JP6701554B2 - Developing method, image forming method and image forming method - Google Patents

Description

The present invention relates to a developing method, an image forming method and an image forming method .

  Conventionally, a carrier that conveys the developer in the circulation conveyance path and a position where the developer supplied from the circulation conveyance path is carried on the surface of itself and the latent image carrier faces the movement of the surface of the developer itself. There is known a developing device having a developer carrying member that conveys the latent image on the latent image carrying member to develop it.

  For example, the developing device described in Japanese Patent Laid-Open No. 2004-187242 is a circulation transfer that circulates a developer containing a toner and a carrier between two transfer paths that transfer the developer in accordance with the rotational driving of a screw member that is a transfer member. Have a road. Then, after the developer supplied to the developing sleeve, which is the developer carrying member, from one of the conveying paths in the circulation conveying path is carried on the surface of the developing sleeve, the developing agent is transferred to the photosensitive member, which is the latent image carrying member, as the developing sleeve rotates. The latent image on the photoconductor is developed by developing the latent image on the photoconductor so as to obtain a toner image.

  The carrier described in Patent Document 2 is known as a carrier contained in the developer. In this carrier, the surface of a particle core material is coated with a resin coating layer, and the resin coating layer is made of a silicon resin in which fine particles of barium sulfate are dispersed. Since fine particles of barium sulfate are harder than silicone resin, it is possible to suppress abrasion of the resin coating layer due to friction and to accelerate charging of the toner, and to charge the toner satisfactorily for a long period of time. Has been done.

  However, according to the experiments by the present inventors, even if such a carrier is used, depending on the configuration of the developing device, a poor charging of the toner may be caused even though the carrier is not used for a long period of time. found.

In order to solve the above-mentioned problems, the present invention provides a circulation conveyance path for circulating and conveying a developer containing a toner and a carrier, a conveyance body for conveying the developer in the circulation conveyance path, and the circulation. A developer that carries the developer supplied from the carrying path on its own surface and then carries it to a position facing the latent image carrier along with its own surface movement to develop the latent image on the latent image carrier. A developing method of a developing device having a carrier, wherein as the carrier, a resin coating layer in which fine particles of barium sulfate are dispersed is coated on the surface of a particle core material, and an image of 40,000 pages from the initial stage is used. The developing method, wherein a stress that increases the abundance ratio of the barium sulfate fine particles on the surface of the carrier from the initial stage is applied to the carrier within a period until the development .

  According to the present invention, there is an excellent effect that the toner in which the surface of the particle core material is coated with the resin coating layer can reliably charge the toner favorably for a long period of time in the developing device.

FIG. 1 is a schematic configuration diagram showing a copying machine according to an embodiment. FIG. 3 is an enlarged configuration diagram showing any one of Y, M, C, and K image forming units in the copying machine together with an intermediate transfer belt and a primary transfer bias roller. FIG. 3 is a perspective view showing the image forming unit. FIG. 3 is an enlarged configuration diagram showing a developing device of the image forming unit. The block diagram which shows the 1st example of the conventional low stress developing device. The block diagram which shows the 2nd example of the conventional low stress developing device. FIG. 3 is an enlarged cross-sectional view partially showing the magnetic carrier in an initial state set in the developing device of the image forming unit (the developing device according to the embodiment). The figure which shows the electronegativity table of Pauling. The figure which showed typically the carrier surface set to the same developing device and used for a certain period of time. The figure which showed typically the carrier surface set to the low stress developing device of the 1st example, and used over a certain period of time. 6 is a graph showing changes over time in toner charge amount (Q/M) when a test image is continuously printed using a low temperature fixing toner B using MPC8002 manufactured by Ricoh Co., Ltd. as a printer tester. 6 is a graph showing a change over time in toner charge amount (Q/M) when a test image is continuously printed using a low temperature fixing toner B using MPC4502 manufactured by Ricoh Co., Ltd. as a printer tester. 9 is a graph showing changes over time in toner charge amount (Q/M) when a test image is continuously printed using a low temperature fixing toner B using MPC4503 manufactured by Ricoh Co., Ltd. as a printer tester. 6 is a graph showing changes with time in toner charge amount in the first experiment. The graph which shows the result which measured the abundance ratio of the electrification microparticles C _a1 (barium sulfate in the first experiment) on the carrier surface by XPS. FIG. 3 is an enlarged configuration diagram showing a developing device of the copying machine according to the first embodiment. FIG. 6 is a partial perspective view showing a supply and recovery screw in a copying machine according to a second embodiment. FIG. 6 is a configuration diagram showing a developing device according to a third embodiment.

An embodiment of a tandem color copying machine (hereinafter referred to as copying machine 500) will be described below as an image forming apparatus to which the present invention is applied.
FIG. 1 is a schematic configuration diagram showing a copying machine 500 according to the embodiment. The copying machine 500 includes a printer unit 100, a document reading unit 4, a document feeding unit 3, a paper feeding unit 7, and the like. The printer unit 100, the document reading unit 4, and the document conveying unit 3 are sequentially stacked on the paper feeding unit 7.

  The document feeding unit 3 feeds the document to the document reading unit 4, and the document reading unit 4 reads the image information of the fed document. The paper feeding unit 7 is a recording medium accommodation unit that accommodates a recording sheet P that is a recording medium, and includes a paper feeding cassette 26 in which a plurality of recording sheets P are stacked and accommodated, and a recording sheet P in the paper feeding cassette 26. A sheet feeding roller 27 that sends the sheet toward the printer unit 100 is provided. The dashed-dotted line in the figure indicates the conveyance path of the recording sheet P in the copying machine 500.

  A discharge tray 30 on which the recording sheets P on which the output images are formed is stacked is arranged above the printer unit 100. The printer unit 100 includes four image forming units 6 (Y, M, C, K) for forming toner images of respective colors (yellow, magenta, cyan, black), and an intermediate transfer unit 10.

  The image forming unit 6 (Y, M, C, K) includes a drum-shaped photoconductor 1 (Y, M, C, K) as an image carrier on which toner images of respective colors are formed, and a photoconductor (Y, M, C). The developing device 5 (Y, M, C, K) for developing the electrostatic latent image formed on the surface of (M, C, K) is provided.

  The intermediate transfer unit 10 includes an intermediate transfer belt 8 stretched by a plurality of stretching rollers and a primary transfer bias roller 9 (Y, M, C, K). The intermediate transfer belt 8 carries a primary color toner image on which the Y, M, C, and K toner images formed on the surfaces of the photoconductors 1Y, 1M, 1C, and 1K are superposed and primarily transferred. To the primary transfer bias rollers 9Y, 9M, 9C and 9K, a primary transfer bias having a polarity opposite to the normal charging polarity of toner is applied. As a result, primary transfer electric fields are formed between the photoconductors 1Y, 1M, 1C and 1K and the primary transfer bias rollers 9Y, 9M, 9C and 9K, respectively. Due to the action of the primary transfer electric field and the primary transfer nip pressure, the toner images of Y, M, C, and K on the photoconductors 1Y, 1M, 1C, and 1K are primarily transferred to the intermediate transfer belt 8.

  The image forming units 6Y, 6M, 6C and 6K are arranged so as to face the intermediate transfer belt 8 of the intermediate transfer unit 10 and to perform primary transfer in the order of Y, M, C and K in the belt moving direction. ing.

  A secondary transfer bias roller 19 is disposed on the right side of the intermediate transfer belt 8 in the figure, and a belt front surface is provided with respect to a portion of the intermediate transfer belt 8 which is wound around the secondary transfer counter roller in the circumferential direction. Abutting from the side, a secondary transfer nip is formed. The recording sheet P is fed into the secondary transfer nip at a predetermined timing. Specifically, the recording sheet P sent from the paper feed cassette 26 by the paper feed roller 27 strikes the registration nip of the registration roller pair 28 through the paper feed path. The registration roller pair 28 rotates the rollers at a predetermined timing to feed the recording sheet P toward the secondary transfer nip. As a result, at the secondary transfer nip, the color toner image on the intermediate transfer belt 8 and the recording sheet P are synchronized with each other and both are in close contact with each other. Then, due to the action of the secondary transfer electric field formed by the secondary transfer bias applied to the secondary transfer bias roller 19 and the action of the secondary transfer nip pressure, the color toner image on the intermediate transfer belt 8 is transferred onto the surface of the recording sheet P. Is secondarily transcribed.

  The recording sheet P that has passed through the secondary transfer nip is fed into the fixing device 20, and is pressurized or heated when passing through the fixing nip, so that the unfixed toner image on the surface is fixed. Be punished.

  Toner containers 11Y, 11M, 11C and 11K are arranged below the discharge tray 30 in the printer unit 100 and above the intermediate transfer unit 10. The toner containers 11Y, 11M, 11C and 11K containing the Y, M, C and K toners to be supplied to the developing devices 5Y, 5M, 5C and 5K are configured to be attachable to and detachable from the printer unit 100. ing.

  Below the image forming units 6Y, 6M, 6C, 6K in the printer unit 100, a latent image for forming an electrostatic latent image by irradiating the surface of the photoconductors 1Y, 1M, 1C, 1K with a laser beam L. An exposure device 12 as a forming means is provided.

  FIG. 2 is an enlarged configuration diagram showing any one of the image forming units 6 (Y, M, C, K) for Y, M, C, K together with the intermediate transfer belt 8 and the primary transfer bias roller 9. is there. In the figure, suffixes Y, M, C, K added to the end of the reference numerals of the respective members are omitted. Also in the following description, the subscripts are appropriately omitted. The configurations of the image forming units for the respective colors are the same, except that the colors of the toners used are different.

  FIG. 3 is a perspective view showing the image forming unit 6. The image forming unit 6 has a structure in which the photoconductor 1, the developing device 5, the cleaning device 2, the charging device 40, and the charge removing unit are held by a common holding body and are integrated into a unit. As a result, the replaceability of the photoconductor 1, the developing device 5, the photoconductor cleaning device 2, and the charging device 40 is facilitated, and the maintainability of the copying machine 500 is improved.

  The photoconductor cleaning device 2 removes the transfer residual toner on the photoconductor 1 from the photoconductor 1 by the cleaning blade 2a. Further, the charging device 40 is configured to generate electric discharge between the charging roller 4a to which a charging bias is applied and the photoconductor 1 to uniformly charge the photoconductor 1. It should be noted that the charge removing unit removes residual charges on the surface of the photoconductor 1 after cleaning.

  In FIG. 1, when the start button is pressed while the original is set on the original table of the original conveying section 3, the original is conveyed by the conveying rollers of the original conveying section 3 from the original table and the original reading section 4 is operated. It is placed on the contact glass. Then, the document reading section 4 optically reads the image information of the document placed on the contact glass.

  Specifically, the document reading unit 4 scans the image of the document on the contact glass while irradiating the light emitted from the illumination lamp. Then, the light reflected by the original is imaged on the color sensor through the mirror group and the lens. The color image information of the original is read by the color sensor for each color separation light of RGB (red, green, blue), and then converted into an electric image signal. Further, processing such as color conversion processing, color correction processing, and spatial frequency correction processing is performed in the image processing unit based on the RGB color separated image signals. As a result, Y, M, C, and K color-separated image information is generated.

  The color-separated image information for Y, M, C, K is sent to the writing control unit for driving the exposure device 12. The writing controller drives the exposure device 12 based on the color-separated image information to oscillate the laser beams L for Y, M, C, and K from the exposure device 12, and thereby the photoconductors 1Y and 1M. , 1C, 1K are optically scanned.

  On the other hand, the photoconductors 1Y, 1M, 1C and 1K are rotationally driven in the clockwise direction in FIGS. 1 and 2 by the drive motor. Then, the surfaces of the photoconductors 1Y, 1M, 1C, 1K are uniformly charged at the portion of the charging device 40 facing the charging roller 4a (charging step). After that, the charged surfaces of the photoconductors 1Y, 1M, 1C, 1K reach the positions where the laser light L is irradiated. In the exposure device 12, laser beams L corresponding to image signals are emitted from four light sources corresponding to Y, M, C and K, respectively. The laser light L for Y, M, C, and K passes through different optical paths for each color component, and is irradiated onto the surface of the photoconductors 1Y, 1M, 1C, and 1K (exposure step).

  The laser light L corresponding to the Y component is applied to the surface of the first Y photoconductor 1Y from the left side of the paper surface of FIG. At this time, the laser light L of the Y component oscillated based on the Y color separation image information from the exposure device 12 arranged below the Y image forming unit 6Y is moved by the polygon mirror that rotates at high speed. Is deflected in the rotation axis direction (main scanning direction) of the photoconductor 1Y. By irradiating the Y photoconductor 1Y through the plurality of optical elements while the laser light L is thus deflected, the surface of the Y photoconductor 1Y after being charged by the charging device 40 is charged. , An electrostatic latent image for Y corresponding to the Y component is formed.

  Similarly, the laser light L corresponding to the M component is applied to the surface of the M photoconductor 1M, which is the second from the left in the drawing of FIG. 1, to form an electrostatic latent image corresponding to the M component. Further, the C component laser beam L is applied to the surface of the third C photoconductor 1C from the left side of the paper surface of FIG. 1 to form a C electrostatic latent image. Further, the laser light L of K component is applied to the surface of the K photoconductor 1K, which is the fourth from the left in the drawing of FIG. 1, to form a K electrostatic latent image.

  After that, the surfaces of the photoconductors 1Y, 1M, 1C and 1K on which the electrostatic latent images for Y, M, C and K are formed reach the positions facing the developing devices 5Y, 5M, 5C and 5K. Then, from the developing devices 5Y, 5M, 5C, 5K containing the developer for Y, M, C, K containing toner and carrier to the electrostatic latent images on the photoconductors 1Y, 1M, 1C, 1K, Y is obtained. , M, C, K toners are supplied to form Y, M, C, K toner images (developing step).

  The surface of the photoconductors 1Y, 1M, 1C, 1K after passing through the developing area at a position facing the developing devices 5Y, 5M, 5C, 5K enters the primary transfer nip for Y, M, C, K, Primary transfer is performed on the surface of the intermediate transfer belt 8 (primary transfer step). Transfer residual toner adheres to the surfaces of the photoconductors 1Y, 1M, 1C and 1K after passing through the primary transfer nips for Y, M, C and K. These are scraped off from the surface of the photoconductors 1Y, 1M, 1C and 1K by the cleaning blade 2a of the photoconductor cleaning device 2 for Y, M, C and K (photoconductor cleaning step).

  The surface of the photoconductor 1 that has passed through the portion facing the photoconductor cleaning device 2 passes through the static elimination portion facing the static elimination means to eliminate residual charges, and a series of image forming processes on the photoconductor 1 are completed. Prepare for the image forming operation.

  The intermediate transfer belt 8 carrying the color toner images by the superimposed transfer of the Y, M, C, and K toner images moves in the counterclockwise direction in FIG. 1 and enters the secondary transfer nip. Then, the recording sheet P fed into the secondary transfer nip as described above is synchronized with the secondary transfer nip. The color toner image on the intermediate transfer belt 8 is secondarily transferred onto the surface of the recording sheet P in the secondary transfer nip (secondary transfer step).

  Transfer residual toner that has not been transferred to the recording sheet P is attached to the surface of the intermediate transfer belt 8 that has passed through the secondary transfer nip. The surface of the intermediate transfer belt 8 that has passed through the secondary transfer nip reaches a portion facing the intermediate transfer belt cleaning device. At this facing portion, the transfer residual toner adhering to the intermediate transfer belt 8 is collected by the intermediate transfer belt cleaning device, and a series of transfer processes on the intermediate transfer belt 8 is completed.

  The recording sheet P to which the color toner image is secondarily transferred at the secondary transfer nip is guided to the fixing device 20. In the fixing device 20, the color image is fixed on the recording sheet P by heat and pressure at the fixing nip formed by the fixing roller and the pressure roller (fixing step).

  The recording sheet P that has passed through the fixing device 20 is discharged as an output image to the outside of the printer unit 100 by the paper discharge roller pair 25 and is stacked on the paper discharge tray 30.

  FIG. 4 is an enlarged configuration diagram showing the developing device 5. The developing device 5 accommodates the developing roller 50 in the developing roller accommodating portion 62. The developing roller 50 includes a rotatable developing sleeve 51 made of a non-magnetic pipe, and a magnet roller 55 included so as not to follow the developing sleeve 51. The magnet roller 55 has a first magnetic pole P1 (S pole), a second magnetic pole P2 (N pole), a third magnetic pole P3 (S pole), a fourth magnetic pole P4 (N pole), and a fourth magnetic pole P4 (N pole) arranged in the roller circumferential direction. It has five magnetic poles P5 (N pole), and these magnetic poles form a plurality of magnetic fields around the developing sleeve 51.

  In the figure, P1 to P5 indicate the distribution of the magnetic flux density (absolute value) in the normal direction on the surface of the developing sleeve 51 of the magnetic field formed by the magnetic poles by dotted lines. The magnetic flux density of the first magnetic pole P1 on the surface of the developing sleeve 51 is 110 [mT]. The magnetic flux density of the second magnetic pole P2 is 70 [mT], the magnetic flux density of the third magnetic pole density P3 is 62 [mT], the magnetic flux density of the fourth magnetic pole density P4 is 42 [mT], and the magnetic flux density of the fifth magnetic pole P5. Is 72 [mT].

  In the developing roller accommodating portion 62, the stress applied to the developer largely depends on the magnetic force of the fifth magnetic pole P5 (the above-mentioned magnetic flux density) and the shapes of the casing and the doctor around P5. The smaller the magnetic force of the fifth magnetic pole P5, the smaller the stress applied to the developer. Further, as the amount of the developer existing within the range of the magnetic force of the fifth magnetic pole P5 decreases, the stress applied to the developer decreases.

  The surface of the developing sleeve 51 is blasted in the developing effective area in the rotation axis direction so that the developer can be satisfactorily carried. A part of the surface of the developing sleeve 51 is partially exposed from the opening 61 of the casing 60 forming the developing roller accommodating portion 62. A region where the exposed portion and the photoconductor 1 face each other is a developing region, and development is performed in this developing region.

  The developing device 5 has a predetermined gap (doctor gap) with respect to a portion of the entire area of the developing sleeve 51 in the circumferential direction, which has passed through a position facing a supply/recovery conveyance path 53a described later and before entering the developing area. It has a doctor blade 51 facing each other. The doctor blade 51 regulates the layer thickness of the developer layer formed on the surface of the developing sleeve 51 and before entering the developing area to a predetermined thickness.

 Further, a magnetic plate 58 is provided adjacent to the upstream side of the doctor blade 52 in the surface movement direction of the developing sleeve 51. The base of the magnetic plate 58 is fixed to the upstream side surface of the doctor blade 52. Further, the tip of the magnetic plate 58 is bent from the base and has a facing surface 58a facing the surface of the developing sleeve 51 on the upstream side of the doctor blade 52 in the sleeve rotation direction.

  Below the developing roller accommodating portion 62, a supply/recovery conveying path 53a for conveying the developer G containing a magnetic carrier (hereinafter also simply referred to as a carrier) and a toner is arranged. Further, on the left side of the supply/recovery conveyance path 53a in the drawing, a stirring conveyance path 54a for conveying the developer G is arranged. The agitating/conveying path 54a communicates with the toner supply port (64 in FIG. 3) through an opening formed above the agitating/conveying path 54a. The supply/recovery conveyance path 53a on the developing sleeve 51 side and the stirring conveyance path 54a on the toner supply port 64 side are separated by a partition wall 57. However, at both ends in the longitudinal direction (the direction orthogonal to the paper surface of the drawing) of both transport paths, both transport paths communicate with each other through the openings provided in the partition wall 57.

  The supply/recovery conveyance path 53 a on the developing sleeve 51 side has a communication port 59 with the developing roller accommodating portion 62. A supply/recovery screw 53 that conveys the developer G in the direction of the rotation axis while stirring the developer G as it is rotationally driven is arranged in the supply/recovery transfer path 53a. A supply/recovery screw 53 that conveys the developer G in the direction of the rotation axis while stirring the developer G as it is rotationally driven is disposed in the stirring/conveying path 54a. These two screws convey the developer in directions opposite to each other in the rotation axis direction.

  In the supply/recovery conveyance path 53a, the developer G is conveyed from one end side to the other end side in the rotation axis direction as the supply/recovery screw 53 is rotationally driven, and from the supply/recovery conveyance path 53a near the other end. It is delivered to the stirring/transporting path 54a. Then, in the stirring/transporting path 54a, the developer G is transported from the other end side to the one end side in the rotation axis direction along with the rotational driving of the stirring/transporting screw 54, and is supplied from the stirring/transporting path 54a near one end. It is delivered to the collecting and conveying path 53a. In this way, the developer G is circulated and conveyed between the stirring/conveying passage 54a and the supply/recovery conveying passage 53a. That is, in the developing device 5, the combination of the agitation transport path 54a and the supply/recovery transport path 53a functions as a circulation transport path that circulates the developer.

  The developer G in the developing device 5 is adjusted so that the ratio of toner in the developer (toner concentration) falls within a predetermined range. More specifically, the toner replenishing device is driven according to the decrease in the toner concentration of the developer due to the development, and the toner contained in the toner container 11 (see FIG. 1) is agitated and conveyed through the toner replenishing device 54a. A proper amount is replenished inside. A concentration detection sensor 56 for detecting the toner concentration of the developer is provided on the bottom surface of the stirring/conveying path 54a. When the concentration detection sensor 56 detects that the toner concentration of the developer in the circulation conveyance path is insufficient, the toner replenishing device is driven to move the toner from the toner container 11 (see FIG. 1) into the stirring conveyance path 54a via the toner replenishment port 64. Toner is replenished.

  In the supply/recovery conveyance path 53a, among the developers G agitated and conveyed as the supply/recovery screw 53 is rotationally driven, the developer G attracted to the developing sleeve 51 by the magnetic force of the fifth magnetic pole P5 of the magnet roller 55. The toner is carried on the developing sleeve 51 through the communication port 59. At this time, the stress applied by the fifth magnetic pole P5 is relatively strong among the stresses applied to the developer. In order to adjust the stress applied to the carrier of the developer in the developing device 5 to a certain level or more, the magnetic force of the fifth magnetic pole P5 is made relatively large, and a large amount of the developer is present in the magnetic field influence range of the fifth magnetic pole P5. You should do so.

  The developer G attracted by the magnetic pole of the fifth magnetic pole P5 is carried by the scooping portion 511 which is a supply position on the surface of the developing sleeve 51. The carrier in the developer G is attracted to the developing sleeve 51 by the magnetic force of the magnet roller 55 contained in the developing sleeve 51, and is carried on the developing sleeve 51. Further, the toner in the developer G is charged to the opposite polarity to the carrier due to frictional charging with the carrier when the developer G is stirred, and electrostatic force acts between the carrier and the toner, so that the toner is adsorbed to the carrier. And is carried on the developing sleeve 51 together with the carrier. Then, the developer G carried on the developing sleeve 51 moves around the developing roller 50 as the developing sleeve 51 rotates.

  The developer G carried on the developing sleeve 51 is conveyed in the counterclockwise direction in FIG. 2 as the developing sleeve 51 rotates, and reaches the position where the doctor blade 52 and the surface of the developing sleeve 51 face each other. Then, the developer G on the developing sleeve 51 passes through a gap (doctor gap) between the doctor blade 52 and the surface of the developing sleeve 51 at this position, so that the layer thickness is regulated and the developer amount is optimized. To be done. On the upstream side of the doctor blade 52, the facing surface 58a of the magnetic plate 58 is provided so as to face the developing sleeve 51. By the action of the facing surface 58a, the stirring function of the developer in the doctor blade 52 portion can be improved.

  When the developer G on the developing sleeve 51 that has passed through the doctor blade 52 is conveyed to the developing area facing the photoconductor 1, the developer G stands up on the developing sleeve 51 by the magnetic force of the magnet roller 55. The developing sleeve 51 moves in the same direction in the developing region at a linear velocity higher than that of the surface of the photoreceptor 1. Then, the carrier standing on the developing sleeve 51 supplies the toner adhering to the surface of the photoconductor 1 to the surface of the photoconductor 1 while rubbing the surface of the photoconductor 1. Since the developing bias is applied to the developing sleeve 51 from the power source, a developing electric field is formed in the developing area.

  Between the electrostatic latent image on the photoconductor 1 and the developing sleeve 51, an electrostatic force toward the electrostatic latent image side acts on the toner on the developing sleeve 51. As a result, the toner on the developing sleeve 51 adheres to the electrostatic latent image on the photoconductor 1. Due to this adhesion, the electrostatic latent image on the photoconductor 1 is developed into a toner image. After that, the developer G of which the toner on the developing sleeve 51 has been consumed reaches the upper side of the developing roller accommodating portion 62 as it rotates, and is separated from the surface of the developing sleeve 51 at this position.

  The developer G on the surface of the developing sleeve 51 is generated by the magnetic force at the inflection point 512 which is a developer separating magnetic pole composed of the fourth magnetic pole P4 and the fifth magnetic pole P5 which are magnetic poles of the same polarity (N pole) adjacent to each other. By the action, the developing sleeve 51 is separated from the surface.

  In the copying machine according to the embodiment, the low temperature fixing toner is used as the toner supplied to the developer. Since the low-temperature fixing toner is softened and fixed at a relatively low heating temperature, the fixing temperature can be lowered and the cost can be reduced. It is a toner that is favorably used in recent years when energy saving is promoted.

  The mode in which the copying machine or the developing device 5 uses a specific toner means, for example, a mode in which the copying machine or the developing device 5 is shipped with the specific toner stored therein. A mode in which the product name or product number of a specific toner is described as the toner to be set in the instruction manual also corresponds to the specific “use toner” mode. The same applies to the mode in which the copying machine or the developing device 5 uses a specific carrier.

  As a method for producing a low-temperature fixing toner excellent in low-temperature fixing property, a method of producing a toner from an elongation reaction product of urethane-modified polyester as a toner binder is disclosed (for example, JP-A No. 11-133665). .. Further, a method for producing a toner which is excellent in powder flowability and transferability in the case of a small particle diameter toner and is also excellent in heat resistant storage stability, low temperature fixing property and high temperature offset resistance is also disclosed (for example, JP-A-2002-287400 and JP-A-2002-351143). Further, a method for producing a toner having a aging step for producing a toner binder having a stable molecular weight distribution and achieving both low-temperature fixing property and high-temperature offset resistance is disclosed (for example, Japanese Patent No. 2579150 and Japanese Patent Laid-Open No. 7579150). 2001-158819). Further, for the purpose of obtaining good low-temperature fixability, a toner containing a resin containing a crystalline polyester resin and a releasing agent, and having a sea-island phase separation structure in which the resin and the wax are incompatible with each other is also disclosed. (For example, Japanese Patent Laid-Open No. 2004-46095). Further, a toner containing a crystalline polyester resin, a release agent and a graft polymer has also been proposed (for example, Japanese Patent Application Laid-Open No. 2007-271789). Since these techniques melt the crystalline polyester resin more rapidly than the amorphous polyester resin, it is possible to realize low-temperature fixing. However, even if the crystalline polyester resin corresponding to the island in the sea-island phase separation structure is melted, most of the amorphous polyester resin corresponding to the sea is not melted yet. Then, both the crystalline polyester resin and the amorphous polyester resin do not fix unless they are melted to some extent, and therefore these techniques do not satisfy the high level low-temperature fixability that has been further increased in recent years.

  As a toner containing an amorphous polyester obtained by reacting a reactive precursor having a branched structure having a very low glass transition temperature with a curing agent for the purpose of obtaining a higher level of low-temperature fixing property, for example, Japanese Patent No. 5408210 is used. The one described in Japanese Patent Publication is known. This toner utilizes the property that the polyester resin, which has a very low glass transition temperature, is deformed at low temperature. It is deformed by heat and pressure during fixing, and is easily adhered to a recording medium such as paper at a lower temperature. Is used to realize a high level of low-temperature fixability. In addition, since the reactive precursor is non-linear, it has a branched structure in the molecular skeleton, and the molecular chain has a three-dimensional network structure, so it deforms at low temperature, but it does not flow like rubber. It has the property. Therefore, it is possible to maintain the heat resistant storage stability and the high temperature offset resistance of the toner.

  In the copying machine according to the embodiment, the toner charging performance of the carrier is stably and satisfactorily maintained for a long period of time even when the low-temperature fixing toner in which the spent layer of the base resin component is easily generated on the carrier surface is used. Is provided (the details will be described later). However, even if the toner does not have low-temperature fixability, as a result of adding a large amount of an external additive typified by silica or titanium oxide for the purpose of imparting fluidity to the toner, the external additive is The same effect can be obtained even in the case of spending money on the carrier. Further, in order to cover the decrease in stress resistance of the base material resin due to low temperature fixing, a toner to which a large amount of an external additive represented by silica or titanium oxide is added may suppress the spent of the base material resin. Instead, it is more likely to cause spent of the external additive. Even when such a toner is used, the same effect can be exhibited.

  The toner used in the copying machine according to the embodiment contains an amorphous polyester resin and a crystalline polyester resin, and further contains other components such as a colorant, if necessary. In order to improve the low-temperature fixability, it is conceivable to lower the glass transition temperature or lower the molecular weight so that the polyester resin (for example, amorphous polyester resin) is melted together with the crystalline polyester resin. However, simply lowering the glass transition temperature or the molecular weight of the polyester resin may deteriorate the heat-resistant storage stability of the toner and the high-temperature offset property during fixing when the melt viscosity is reduced. high. On the other hand, the polyester resin used as the base material resin of the toner used in the copying machine according to the embodiment contains an amorphous polyester resin A, an amorphous polyester resin B, and a crystalline polyester resin C described later. is doing.

  Since the amorphous polyester resin A described later has a very low glass transition temperature, it has a property of being deformed at a low temperature, is deformed by overheat and pressure at the time of fixing, and is a recording medium such as paper at a lower temperature. It has the property of easily adhering to. In addition, since the reactive precursor is non-linear, it has a branched structure in the molecular skeleton, and the molecular chain has a three-dimensional network structure, so it deforms at low temperature, but it does not flow like rubber. It has the property. As a result, it becomes possible to easily maintain the heat resistant storage stability and the high temperature offset resistance of the toner. When the amorphous polyester resin A has a urethane bond or a urea bond with high cohesive energy, the adhesiveness to a recording medium such as paper is more excellent. Further, since the urethane bond or urea bond behaves like a pseudo-crosslinking point, the rubber-like property becomes stronger, and as a result, the toner has excellent heat-resistant storage stability and high-temperature offset resistance. That is, the toner used in the copying machine according to the embodiment has an amorphous polyester resin A, which has a glass transition temperature in an ultra-low tone region but has a high melt viscosity and is hard to flow, an amorphous polyester resin B, and a crystalline property. By containing the polyester resin C, it becomes possible to maintain heat resistant storage stability and high temperature offset resistance even if the glass transition temperature is set lower than in the past.

  The above-mentioned amorphous polyester resin A is obtained by the reaction between a non-linear reactive precursor and a curing agent, and has a glass transition temperature of −60 [° C.] or higher and lower than 0° C. The amorphous polyester resin A contains at least one of a urethane bond and a urea bond from the viewpoint of more excellent adhesiveness to a recording sheet such as paper. When the amorphous polyester resin A contains at least one of a urethane bond and a urea bond, the urethane bond or the urea bond behaves like a pseudo cross-linking point, and the amorphous polyester resin A has rubber properties. Make stronger This improves heat resistant storage stability and high temperature offset resistance of the toner. Details of such an amorphous polyester resin A are described in JP 2013-225096 A and the like.

  In order to lower the glass transition temperature Tg of the polyester resin A and to easily impart the property of deforming at low temperature, it is desirable that the polyester resin A contains a diol component. This diol component preferably contains an aliphatic diol having 3 or more and 12 or less carbon atoms, and more preferably 4 or more carbon atoms.

  The polyester resin A preferably contains an aliphatic diol having 3 to 12 carbon atoms in an amount of 50 [mol%] or more, more preferably 80 [mol%] or more, and 90 mol [% or more] or more. Is more preferable. Examples of the aliphatic diol having 3 to 12 carbon atoms include 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol and 3-methyl- Examples include 1,5-pentanediol and the like. Further, it may be 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol or the like.

The diol component contained in the polyester resin A is an aliphatic diol having 4 or more and 12 or less carbon atoms, the main chain of the diol component has an odd number of carbon atoms, and has an alkyl group in its side chain. It is preferably one. As the aliphatic diol having a carbon number of the main chain portion that is an odd number and having an alkyl group in the side chain and having 4 to 12 carbon atoms, an aliphatic diol represented by the chemical formula "HO-(CR1R2) _n -OH" A diol can be illustrated. In this chemical formula, R1 and R2 represent an alkyl group having 1 to 3 carbon atoms. n represents an odd number of 3-9. In each of the n repeating units, R1 may be the same or different. In the n repeating units, R2 may be the same or different.

  In order to lower the glass transition temperature Tg of the polyester resin A and to easily impart the property of deforming at a low temperature, the polyester resin A contains an aliphatic diol having 3 or more and 12 or less carbon atoms in an amount of 50 or more in all alcohol components. mol%] or more is preferable. Further, it is preferable to contain 30 [mol%] or more of an aliphatic dicarboxylic acid having 4 to 12 carbon atoms. Examples of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and dodecanedioic acid.

  The diol component is not particularly limited and can be appropriately selected according to the purpose. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 3-methyl-1, 5-pentanediol etc. can be illustrated. Further, aliphatic diols such as 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol and 1,12-dodecanediol; diethylene glycol, triethylene glycol, dipropylene glycol and the like may be used. .. Also, a diol having an oxyalkylene group such as polyethylene glycol, polypropylene glycol or polytetramethylene glycol; 1,4-cyclohexanedimethanol may be used. It may also be an alicyclic diol such as hydrogenated bisphenol A (an alicyclic diol to which an alkylene oxide such as ethylene oxide, propylene oxide or butylene oxide is added). Further, it may be an alkylene oxide adduct of bisphenol. The busphenols are bisphenols such as bisphenol A, bisphenol F and bisphenol S, to which alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide are added. Of these, aliphatic diols having 4 to 12 carbon atoms are preferable. These diols may be used alone or in combination of two or more.

  The dicarboxylic acid component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aliphatic dicarboxylic acid and aromatic dicarboxylic acid. Moreover, these anhydrides may be used, a lower (C1-C3) alkyl ester compound may be used, and a halide may be used. The aliphatic dicarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid and fumaric acid. The aromatic dicarboxylic acid is appropriately selected depending on the intended purpose without any limitation, but it is preferably an aromatic dicarboxylic acid having 8 to 20 carbon atoms. The aromatic dicarboxylic acid having 8 to 20 carbon atoms is appropriately selected depending on the intended purpose without any limitation, and examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Among these, an aliphatic dicarboxylic acid having 4 to 12 carbon atoms is preferable. These dicarboxylic acids may be used alone or in combination of two or more.

  The above-mentioned trihydric or higher alcohol is not particularly limited and may be appropriately selected according to the purpose. For example, trihydric or higher aliphatic alcohol, trihydric or higher polyphenols, trihydric or higher polyphenols may be selected. Examples thereof include alkylene oxide adducts. Examples of the trihydric or higher aliphatic alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol. Examples of the trivalent or higher polyphenols include trisphenol PA, phenol novolac, and cresol novolac. Examples of the alkylene oxide adduct of polyphenols having a valence of 3 or more include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to a polyphenol having a valence of 3 or more.

  The polyisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diisocyanate and trivalent or higher valent isocyanate. Examples of the diisocyanate include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and the like in which these are blocked with a phenol derivative, oxime, caprolactam, or the like. Examples of the trivalent or higher valent isocyanate include lysine triisocyanate, a trivalent or higher valent alcohol reacted with a diisocyanate, and a polyisocyanate reacted to form an isocyanurate. Above all, it is preferable to use a polyisocyanate having an isocyanurate skeleton because it acts as a stronger cross-linking point and is further excellent in heat resistant storage stability and high temperature offset resistance. The content of the trivalent isocyanate component is preferably 0.2 [mol]% or more and 1.0 mol [%] or less with respect to the resin composition content in the THF insoluble content of the toner. When a crosslinked structure is formed from a trivalent isocyanate component, the cohesive force of the molecular chain is increased due to pseudo-crosslinking due to urethane or urea bond at the crosslink point, so good heat resistant storage stability is exhibited even with a small crosslink density, and low temperature fixing Can be achieved at a high level. If the trivalent isocyanate component is less than 0.2 [mol %], the branched structure will be insufficiently formed, and the portion where the network structure becomes nonuniform becomes the starting point, so that heat resistance storage stability and filming resistance May worsen. When the trivalent isocyanate component is more than 1.0 [mol]%, a low temperature fixing property may be deteriorated due to the formation of a dense crosslinked structure.

  The aliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate and decamethylene. Examples thereof include diisocyanate. Further, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane diisocyanate, etc. may be used.

  The alicyclic diisocyanate is appropriately selected depending on the intended purpose without any limitation, and examples thereof include isophorone diisocyanate and cyclohexylmethane diisocyanate. The aromatic diisocyanate is not particularly limited and may be appropriately selected depending on the purpose. For example, tolylene diisocyanate, diisocyanato diphenyl methane, 1,5-naphthylene diisocyanate, 4,4′-diisocyanato diphenyl, 4,4′-diisocyanato-3,3′-dimethyldiphenyl and the like can be exemplified. .. Further, 4,4'-diisocyanato-3-methyldiphenylmethane, 4,4'-diisocyanato-diphenyl ether, or the like may be used.

  The araliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include α,α,α′,α′-tetramethylxylylene diisocyanate. The isocyanurates are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include tris(isocyanatoalkyl)isocyanurate and tris(isocyanatocycloalkyl)isocyanurate. These polyisocyanates may be used alone or in combination of two or more.

  The curing agent is not particularly limited as long as it is a curing agent capable of reacting with a polyester prepolymer to form the polyester resin A, and can be appropriately selected according to the purpose. For example, an active hydrogen group-containing compound and the like can be mentioned.

  The active hydrogen group in the active hydrogen group-containing compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups. And so on. These may be used alone or in combination of two or more.

  The active hydrogen group-containing compound is not particularly limited and may be appropriately selected depending on the intended purpose, but amines are preferable because they can form a urea bond. The amines are not particularly limited and can be appropriately selected depending on the purpose. For example, diamines, trivalent or higher valent amines, amino alcohols, amino mercaptans, amino acids, and those in which these amino groups are blocked may be mentioned. These may be used alone or in combination of two or more. Among these, diamine and a mixture of diamine and a small amount of trivalent or higher amine are preferable.

  The diamine is appropriately selected depending on the intended purpose without any limitation, and examples thereof include aromatic diamine, alicyclic diamine, and aliphatic diamine. The aromatic diamine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include phenylenediamine, diethyltoluenediamine and 4,4'-diaminodiphenylmethane. The alicyclic diamine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diaminocyclohexane and isophoronediamine. Is mentioned. The aliphatic diamine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ethylenediamine, tetramethylenediamine and hexamethylenediamine. The trivalent or higher amine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diethylenetriamine and triethylenetetramine. The amino alcohol is appropriately selected depending on the intended purpose without any limitation, and examples thereof include ethanolamine and hydroxyethylaniline. The amino mercaptan is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aminoethyl mercaptan and aminopropyl mercaptan. The amino acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aminopropionic acid and aminocaproic acid. Further, the blocked amino group is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include ketimine compounds and oxazoline compounds obtained by blocking an amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

  The glass transition temperature Tg of the polyester resin A is preferably −60 [° C.] or higher and 0 [° C.] or lower, and more preferably −40 [° C.] or higher and −20 [° C.] or lower. If the glass transition temperature Tg is less than -60 [°C], the flow of the toner at a low temperature cannot be suppressed, and the heat-resistant storage stability may deteriorate or the filming resistance may deteriorate. Further, when the glass transition temperature Tg exceeds 0 [° C.], the toner due to heating and pressure during fixing cannot be sufficiently deformed, and the low-temperature fixability may be insufficient.

  The weight average molecular weight of the polyester resin A is not particularly limited and can be appropriately selected depending on the purpose. However, in GPC (gel permeation chromatography) measurement, 20,000 or more and 1,000,000 or less are preferable. The weight average molecular weight is a molecular weight of a reaction product obtained by reacting the reactive precursor with the curing agent. If the weight average molecular weight is less than 20,000, the toner may easily flow at low temperature and may have poor heat resistant storage stability. Further, the viscosity at the time of melting may be lowered, and the high temperature offset property may be lowered.

  The above-mentioned amorphous polyester resin B is preferably a polyester resin having a glass transition temperature Tg of 40[° C.] or higher and 70[° C.] or lower. And it contains a diol component and a dicarboxylic acid component. The other polyester resin is preferably a linear polyester resin.

  The other polyester resin is preferably an unmodified polyester resin. The unmodified polyester resin is the following polyester resin. That is, a polyester obtained by using a polyvalent alcohol and a polyvalent carboxylic acid, a polyvalent carboxylic anhydride, a polyvalent carboxylic acid such as a polyvalent carboxylic acid ester or a derivative thereof, and not modified by an isocyanate compound or the like. It is a resin. Details of such a polyester resin are described in JP 2013-225096 A and the like.

  Examples of the polyhydric alcohol include diol and the like. Examples of the diol include ethylene glycol, propylene glycol; hydrogenated bisphenol A, alkylene (carbon number 2 to 3) oxide (average added mole number 1 to 10) adduct of hydrogenated bisphenol A, and the like. It is an alkylene (C2-3) oxide (average addition mole number 1-10) adduct of bisphenol A. Examples of the bisphenol A include polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene (2.2)-2,2-bis(4-hydroxyphenyl)propane. Can be mentioned. These may be used alone or in combination of two or more.

  Examples of the polycarboxylic acid include dicarboxylic acid. Examples of the dicarboxylic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid; dodecenylsuccinic acid, octylsuccinic acid, and other alkyl groups having 1 to 20 carbon atoms or alkenyl groups having 2 to 20 carbon atoms. Examples include substituted succinic acid. These may be used alone or in combination of two or more.

  For the purpose of adjusting the acid value or the hydroxyl value, the other polyester resin may contain at least one of a trivalent or higher carboxylic acid and a trivalent or higher alcohol at the end of the resin chain. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, and acid anhydrides thereof. Examples of trihydric or higher alcohols include glycerin, pentaerythritol, and trimethylolpropane.

  The molecular weight of the polyester resin B is not particularly limited and can be appropriately selected according to the purpose. However, if the molecular weight is too low, the heat-resistant storage stability of the toner and durability against stress such as stirring in the developing machine may be poor.If the molecular weight is too high, the viscoelasticity of the toner during melting becomes high and the low temperature fixability is improved. May be inferior to. Therefore, in GPC (gel permeation chromatography) measurement, the weight average molecular weight (Mw) is preferably 3,000 to 10,000. The number average molecular weight (Mn) is preferably 1,000 to 4,000. In addition, Mw/Mn is preferably 1.0 to 4.0. Further, the weight average molecular weight (Mw) is more preferably 4,000 to 7,000. Further, the number average molecular weight (Mn) is more preferably 1,500 to 3,000. Further, the Mw/Mn is more preferably 1.0 to 3.5.

  The acid value of the polyester resin B is not particularly limited and can be appropriately selected depending on the purpose. However, it is preferably 1 [mgKOH/g] to 50 [mgKOH/g], and more preferably 5 [mgKOH/g] to 30 [mgKOH/g]. When the acid value is 1 [mgKOH/g] or more, the toner tends to be negatively charged, and further, the affinity between the paper and the toner at the time of fixing to the paper is improved, and the low-temperature fixability is improved. be able to. If the acid value exceeds 50 [mgKOH/g], the charging stability, particularly the charging stability against environmental changes, may be reduced.

  The hydroxyl value of the polyester resin B is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 5 [mgKOH/g] or more.

  The glass transition temperature Tg of the polyester resin B is preferably 40 [° C.] or higher and 70 [° C.] or lower, and more preferably 50 [° C.] or higher and 60 [° C.] or lower. When the glass transition temperature Tg is less than 40 [° C.], the heat resistant storage stability of the toner and the durability against stress such as stirring in the developing machine are deteriorated, and the filming resistance may be deteriorated. If the glass transition temperature Tg exceeds 70[° C.], the deformation due to heating and pressurization at the time of fixing the toner is not sufficient, and the low temperature fixability may be insufficient.

  The molecular structure of the polyester resin A or the polyester resin B can be confirmed by X-ray diffraction, GC/MS, LC/MS, IR measurement or the like in addition to NMR measurement by a solution or solid.

  The content of the polyester resin A and the polyester resin B is not particularly limited and can be appropriately selected according to the purpose. The polyester resin A is preferably contained in an amount of 5 to 25 parts by mass, more preferably 10 to 20 parts by mass, based on 100 parts by mass of the toner. When the content is less than 5 parts by mass, the low temperature fixability and the high temperature offset resistance may deteriorate. On the other hand, if it exceeds 25 parts by mass, heat-resistant storage stability may be deteriorated and glossiness of an image obtained after fixing may be lowered. When the content is within the more preferable range as described above, it is advantageous in that all of the low temperature fixing property, the high temperature offset resistance and the heat resistant storage stability are excellent.

  On the other hand, with respect to 100 parts by mass of the toner, the polyester resin B is preferably contained in a ratio of 50 parts by mass to 90 parts by mass, more preferably 60 parts by mass to 80 parts by mass. If the content is less than 50 parts by mass, the dispersibility of the pigment and the release agent in the toner may be deteriorated, and image fogging and disturbance may be likely to occur. On the other hand, when it exceeds 90 parts by mass, the content of the polyester resin A becomes small, so that the low-temperature fixability may be deteriorated. When the content is in the more preferable range as described above, it is advantageous in that the high image quality and the low temperature fixability are all excellent.

  Since the above-mentioned crystalline polyester resin C has high crystallinity, it exhibits a hot-melt property showing a sharp decrease in viscosity near the fixing start temperature. By including the crystalline polyester resin C having such characteristics together with the polyester resin A and the polyester resin B, the heat resistant storage stability due to the crystallinity is improved until just before the melting start temperature. Then, at the melting start temperature, a sharp decrease in viscosity (sharp melt) is induced by melting of the crystalline polyester resin, and the crystalline polyester resin is compatible with the polyester resin accordingly, and the viscosity is rapidly decreased together, thereby fixing. Therefore, it is possible to obtain a toner having both good heat-resistant storage stability and low-temperature fixability. Also, the release width (difference between the lower limit fixing temperature and the high temperature resistant offset generation temperature) shows good results.

  The crystalline polyester resin C is obtained by using a polyhydric alcohol and a polyvalent carboxylic acid such as a polyvalent carboxylic acid, a polyvalent carboxylic acid anhydride, a polyvalent carboxylic acid ester or a derivative thereof. The crystalline polyester resin is obtained by using a polyhydric alcohol and a polyvalent carboxylic acid such as a polyvalent carboxylic acid, a polyvalent carboxylic acid anhydride or a polyvalent carboxylic acid ester, or a derivative thereof. A modified polyester resin, for example, the above-mentioned prepolymer and a resin obtained by crosslinking and/or elongation reaction of the prepolymer do not belong to the crystalline polyester resin.

  Details of the crystalline polyester resin C are described in JP 2013-225096 A and the like.

  The presence or absence of crystallinity of the crystalline polyester resin can be confirmed by a crystal analysis X-ray diffractometer (for example, X'Pert Pro MRD Phillips). Specifically, first, the target sample is ground with a mortar to prepare a sample powder, and the obtained sample powder is uniformly applied to the sample holder. Then, the sample holder is set in the diffractometer and the diffraction spectrum is measured. In the measurement results, among the plurality of peaks obtained in the range of 20°<2θ<25° with respect to the diffraction peak, if the peak half-width of the peak having the highest peak intensity is 2.0 or less, the crystal You may judge that you have sex. In contrast to the crystalline polyester resin, the polyester resin having no crystallinity as described above is an amorphous polyester resin.

Specific measurement conditions for X-ray diffraction are as follows, for example.
・Tension kV: 45 kV
・Current: 40mA
・MPSS
・Upper
・Gonio
・Scanmode:continuos
・Start angle: 3°
・End angle: 35°
・Angle Step: 0.02°
・Lucient beam optics
・Diverence slit: Div slit 1/2
・Diffusion beam optics
・Anti scatter slit: As Fixed 1/2
・Receiving slit: Prog rec slit

  The polyhydric alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diols and trihydric or higher alcohols. Examples of the diols include saturated aliphatic diols. Examples of the saturated aliphatic diol include straight-chain saturated aliphatic diols and branched saturated aliphatic diols. Among these, straight-chain saturated aliphatic diols are preferable, and straight-chain saturated aliphatic diols having 2 to 12 carbon atoms. Saturated aliphatic diols are more preferred. When the saturated aliphatic diol is branched, the crystallinity of the crystalline polyester resin may be lowered and the melting point may be lowered. If the saturated aliphatic diol has more than 12 carbon atoms, it becomes difficult to obtain a practical material. The carbon number is more preferably 12 or less.

  Examples of the saturated aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol and the like can be exemplified. Further, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol and the like may be used. Further, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol and the like may be used. Among these, the following are preferable in that the crystalline polyester resin has high crystallinity and excellent sharp meltability. That is, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol are preferable.

  Examples of the trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.

  The polyvalent carboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include divalent carboxylic acids and trivalent or higher carboxylic acids. Examples of the divalent carboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, speric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12- Dodecane dicarboxylic acid etc. can be illustrated. Further, saturated aliphatic dicarboxylic acids such as 1,14-tetradecanedicarboxylic acid and 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid and terephthalic acid may be used. Further, aromatic dicarboxylic acids such as dibasic acids such as naphthalene-2,6-dicarboxylic acid, malonic acid and mesaconinic acid may be used. Further, their anhydrides or lower (C1 to C3) alkyl esters may be used.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and their anhydrides and their lower compounds. (C1-C3) alkyl ester etc. are mentioned. In addition to the saturated aliphatic dicarboxylic acid and the aromatic dicarboxylic acid, the polycarboxylic acid may include a dicarboxylic acid having a sulfonic acid group. Further, in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid, a dicarboxylic acid having a double bond may be contained. These may be used alone or in combination of two or more.

  The crystalline polyester resin C is preferably composed of a linear saturated aliphatic dicarboxylic acid having 4 or more and 12 or less carbon atoms and a linear saturated aliphatic diol having 2 or more and 12 or less carbon atoms. That is, it is preferable to have a structural unit derived from a saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a structural unit derived from a saturated aliphatic diol having 2 to 12 carbon atoms. Since such crystalline polyester resin C has high crystallinity and excellent sharp melt property, it can exhibit excellent low-temperature fixability.

  The melting point of the crystalline polyester resin C is appropriately selected depending on the intended purpose without any limitation, but it is preferably 60 [°C] or higher and 80 [°C] or lower. When the melting point is less than 60 [° C.], the crystalline polyester resin C is likely to melt at a low temperature, and the heat-resistant storage stability of the toner may deteriorate. On the other hand, if it exceeds 80 [° C.], the melting of the crystalline polyester resin due to heating at the time of fixing is insufficient, and the low-temperature fixability may decrease.

  The molecular weight of the crystalline polyester resin C is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint that the one having a sharp molecular weight distribution and a low molecular weight has excellent low-temperature fixability, and the heat-resistant storability is deteriorated when there are many components having a low molecular weight, the following molecular weights are preferable. That is, in the GPC measurement of the soluble component of orthodichlorobenzene, the weight average molecular weight (Mw) is 3,000 to 30,000, the number average molecular weight (Mn) is 1,000 to 10,000, and Mw/ It is preferable that Mn is 1.0 to 10. More preferably, the weight average molecular weight (Mw) is 5,000 to 15,000, the number average molecular weight (Mn) is 2,000 to 10,000, and Mw/Mn is 1.0 to 5.0.

  The acid value of the crystalline polyester resin C is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of the affinity between the paper and the resin, it is preferably 5 [mgKOH/g] or more, and more preferably 10 [mgKOH/g] or more, in order to achieve a desired low-temperature fixing property. preferable. On the other hand, in order to improve the high temperature offset resistance, it is preferably 45 [mgKOH/g] or less.

  The hydroxyl value of the crystalline polyester resin C is not particularly limited and can be appropriately selected according to the purpose. In order to achieve a desired temperature fixing property and a good charging characteristic, 0 [mgKOH/g] to 50 [mgKOH/g] is preferable, and 5 [mgKOH/g] to 50 [mgKOH /G] is more preferable.

  The molecular structure of the crystalline polyester resin C can be confirmed by X-ray diffraction, GC/MS, LC/MS, IR measurement, etc., in addition to NMR measurement by solution or solid. For the sake of simplicity, use a method of detecting, as the crystalline polyester resin, an infrared absorption spectrum having absorption based on δCH (out-of-plane bending vibration) of an olefin at 965±10 cm −1 or 990±10 cm−1. You can

  The content of the crystalline polyester resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 parts by mass to 20 parts by mass with respect to 100 parts by mass of the toner, and 5 parts by mass. More preferably, it is from 15 parts by mass to 15 parts by mass. If the content is less than 3 parts by mass, the low-temperature fixability may be poor because the sharp melting by the crystalline polyester resin is insufficient. On the other hand, if it exceeds 20 parts by mass, heat-resistant storage stability may be deteriorated or image fogging may be likely to occur. When the content is within the above-mentioned more preferable range, it is advantageous in that all of the high image quality and the low temperature fixability are excellent.

  Examples of the other components include a release agent (release agent), a colorant, a charge control agent, an external additive, a fluidity improver, and a cleanability improver.

  The release agent is not particularly limited and can be appropriately selected from known release agents. Examples of release agents for waxes and waxes include plant waxes such as carnauba wax, cotton wax, and wood wax rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and sercine; paraffins and the like. Natural wax can be illustrated. Further, natural wax such as petroleum wax such as microcrystalline and petrolatum may be used. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene and polypropylene; synthetic waxes such as esters, ketones and ethers may be used. In addition, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride, and chlorinated hydrocarbons; low molecular weight crystalline polymer resins, and the following crystalline polymers may be used. .. That is, a long-chain alkyl such as a homopolymer or copolymer of polyacrylate such as poly-n-stearyl methacrylate or poly-n-lauryl methacrylate (for example, copolymer of n-stearyl acrylate-ethyl methacrylate). It is a crystalline polymer having a group. Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax and polypropylene wax are preferable.

  The melting point of the release agent is appropriately selected depending on the intended purpose without any limitation, but it is preferably 60 [°C] or higher and 80 [°C] or lower. When the melting point is less than 60 [° C.], the release agent is likely to melt at low temperatures, and the heat resistant storage stability may be poor. When the melting point is higher than 80° C., even if the resin is melted and is in the fixing temperature range, the release agent may not be sufficiently melted to cause fixing offset, resulting in image loss.

  The content of the release agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 2 parts by mass to 10 parts by mass with respect to 100 parts by mass of the toner, and 3 parts by mass. More preferably, it is from 8 parts by mass to 8 parts by mass. If the content is less than 2 parts by mass, the high temperature offset resistance during fixing and the low temperature fixability may be poor. On the other hand, if it exceeds 10 parts by mass, heat-resistant storage stability may be deteriorated or image fogging may be likely to occur. When the content is within the above-mentioned more preferable range, it is advantageous in improving image quality and fixing stability.

  The colorant is not particularly limited and can be appropriately selected according to the purpose. Examples include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, and oil yellow. it can. Also, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Balkan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, etc. good. Further, anthrazan yellow BGL, isoindolinone yellow, red iron oxide, red lead, lead red vermillion, cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, para red, and phise red may be used. Further, parachlor ortho-nitroaniline red, resole fast scarlet G, brilliant fast scarlet, brilliant carnmin BS, permanent red (F2R, F4R, FRL, FRLL, F4RH) may be used. Further, Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, etc. may be used. Further, permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B and the like may be used. Further, thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, etc. may be used. Further, alkali blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, ultramarine blue, navy blue and the like may be used. Further, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, etc. may be used. Further, emerald green, pigment green B, naphthol green B, green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithobon and the like may be used.

  The content of the colorant is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 part by mass to 15 parts by mass with respect to 100 parts by mass of the toner, and 3 parts by mass. More preferably, it is from 10 to 10 parts by mass.

  The colorant can also be used as a masterbatch that is combined with a resin. Examples of the resin to be manufactured or kneaded with the masterbatch include, in addition to the above-mentioned other polyester resins, polymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene or a substitution product thereof; styrene-p- Chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic Butyl acid copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate Copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer , Styrene-based copolymers such as styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, Examples thereof include polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, and paraffin wax. These may be used alone or in combination of two or more.

  The masterbatch can be obtained by mixing a resin for a masterbatch and a colorant by applying a high shearing force and kneading. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. Further, a method of so-called flushing method in which an aqueous paste containing water of a coloring agent is mixed and kneaded with a resin and an organic solvent, the coloring agent is transferred to the resin side, and water and an organic solvent component are also removed. The cake can be used as it is. Therefore, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

  The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdic acid chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), and the like. .. Further, it may be an alkylamide, a simple substance or compound of phosphorus, a simple substance or compound of tungsten, a fluorine-based activator, a salicylic acid metal salt, and a salicylic acid derivative metal salt. Trade names include Bontron 03, a nigrosine dye, Bontron P-51, a quaternary ammonium salt, Bontron S-34, a metal-containing azo dye, E-82, an oxynaphthoic acid metal complex, and E-a salicylic acid metal complex. 84 and E-89 of a phenol-based condensate. All of these are sold by Orient Chemical Industry Co., Ltd. Further, quaternary ammonium salt molybdenum complex TP-302, TP-415, etc., sold by Hodogaya Chemical Co., Ltd. may be used. Further, LRA-901, a boron complex LR-147, etc. sold by Nippon Carlit Co. may be used. Further, copper phthalocyanine, perylene, quinacridone, azo pigments, and other high molecular compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts may be used.

  The content of the charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 part by mass to 10 parts by mass with respect to 100 parts by mass of the toner. It is more preferably 0.2 parts by mass to 5 parts by mass. When the content is more than 10 parts by mass, the chargeability of the toner is too large, the effect of the main charge control agent is diminished, the electrostatic attraction with the developing roller is increased, and the fluidity of the developer is lowered. However, the image density may be lowered. These charge control agents can be melt-kneaded with the masterbatch and the resin and then dissolved and dispersed, or, of course, may be added when directly dissolved or dispersed in an organic solvent, or fixed on the toner surface after the toner particles are prepared. May be.

As the external additive, in addition to oxide fine particles, inorganic fine particles or hydrophobically treated inorganic fine particles may be used in combination, but the average particle size of the hydrophobically treated primary particles is 1 [nm] to 100 [nm]. ] Is preferable. It is more preferable that the inorganic fine particles have an average particle diameter of 5 [nm] to 70 [nm]. In addition, one or more kinds of inorganic fine particles having an average particle diameter of 20 [nm] or less of the primary particles subjected to the hydrophobization treatment are included, and one or more kinds of inorganic fine particles having an average particle diameter of 30 [nm] or more are included. Preferably. In addition, the specific surface area by BET method ^is preferably ^{20 [m 2 / g~500m 2 /} g].

  The external additive is appropriately selected depending on the intended purpose without any limitation. Examples thereof include fine silica particles, hydrophobic silica, fatty acid metal salts (eg, zinc stearate, aluminum stearate, etc.), metal oxides (eg, titania, alumina, tin oxide, antimony oxide, etc.) and fluoropolymers.

  Suitable additives include hydrophobized silica, titania, titanium oxide, and alumina fine particles. Examples of the silica fine particles include R972, R974, RX200, RY200, R202, R805, R812 (all manufactured by Nippon Aerosil Co., Ltd.). Examples of titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Industry Co., Ltd.) and the like. Further, TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.), MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Co., Ltd.) may be used.

  As the hydrophobized titanium oxide fine particles, T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Industry Co., Ltd.), TAF-500T, TAF-1500T (any one). Also manufactured by Fuji Titanium Industry Co., Ltd.) and the like. Further, MT-100S, MT-100T (all manufactured by Teika Co., Ltd.), IT-S (manufactured by Ishihara Sangyo Co., Ltd.) and the like may be used.

  The hydrophobized oxide fine particles, the hydrophobized silica fine particles, the hydrophobized titania fine particles, and the hydrophobized alumina fine particles can be obtained, for example, as follows. That is, it can be obtained by treating hydrophilic fine particles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. Further, silicone oil-treated oxide fine particles and inorganic fine particles obtained by treating silicone oil with heat if necessary to heat it are also suitable.

  Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl modified silicone oil, and fluorine modified silicone oil. Further, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, etc. may be used. Further, carboxyl modified silicone oil, mercapto modified silicone oil, methacryl modified silicone oil, α-methylstyrene modified silicone oil and the like may be used.

  As the inorganic fine particles, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, silica ash. Examples include stone and diatomaceous earth. Further, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like may be used. Among these, silica and titanium dioxide are particularly preferable.

  The content of the external additive is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 part by mass to 5 parts by mass with respect to 100 parts by mass of the toner, It is more preferably 0.3 part by mass to 3 parts by mass.

  The average particle size of the primary particles of the inorganic fine particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 100 [nm] or less and 3 [nm] or more and 70 [nm]. ] The following is more preferable. When it is smaller than this range, the inorganic fine particles are buried in the toner, and it becomes difficult to effectively exhibit its function. On the other hand, if it is larger than the above range, the surface of the photoreceptor is unevenly damaged, which is not preferable.

  The fluidity improver is not particularly limited as long as it can be subjected to surface treatment to increase hydrophobicity and prevent deterioration of fluidity characteristics and charging characteristics even under high humidity, and is appropriately selected according to the purpose. can do. Examples thereof include a silane coupling agent, a silylating agent, a silane coupling agent having a fluoroalkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. It is particularly preferable that the silica and the titanium oxide are surface-treated with such a fluidity improver and used as hydrophobic silica and hydrophobic titanium oxide.

  The cleaning property improver is not particularly limited as long as it is added to the toner in order to remove the developer after transfer remaining on the photoconductor or the primary transfer medium, and may be appropriately selected according to the purpose. You can Examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, and polymer fine particles produced by soap-free emulsion polymerization such as polymethylmethacrylate fine particles and polystyrene fine particles. The polymer particles preferably have a relatively narrow particle size distribution, and preferably have a volume average particle diameter of 0.01 [μm] to 1 [μm].

  The toner used in the copying machine according to the embodiment preferably has a glass transition temperature (Tg1st) of 20 [° C.] or more and 50 [° C.] or less in the first temperature rise of differential scanning calorimetry (DSC). In a general toner, when the glass transition temperature Tg is about 50[° C.] or lower, toner aggregation is likely to occur due to temperature changes during transportation and storage environment of the toner assuming summer and tropical regions. As a result, solidification in the toner bottle and fixing of the toner in the developing machine occur. In addition, defective supply due to toner clogging in the toner container and image abnormality due to toner sticking in the developing device are likely to occur.

  Further, in the toner, since the polyester resin which is a low Tg component is non-linear, the heat resistant storage stability can be maintained. In particular, when the polyester resin having the above-described structure represented by the chemical formula has a urethane bond or a urea bond having high cohesive force, the effect of maintaining heat resistant storage stability becomes more remarkable.

  When the glass transition temperature (Tg1st) in the first temperature rise is less than 20 [° C.], heat-resistant storage stability lowers, blocking in the developing machine, and filming on the photoconductor are likely to occur. If it exceeds 50 [° C.], the low temperature fixability of the toner may deteriorate.

  In the toner, the difference (Tg1st-Tg2nd) between the glass transition temperature (Tg1st) at the first temperature increase and the glass transition temperature (Tg2nd) at the second temperature increase in the differential scanning calorimetry (DSC) is appropriately determined according to the purpose. You can choose. However, it is more preferably 10[° C.] or higher. The upper limit of the difference is appropriately selected depending on the intended purpose without any limitation, but the difference (Tg1st-Tg2nd) is preferably 50[°C] or less.

  When the difference is 10 [° C.] or more, it is advantageous in that the low temperature fixing property is more excellent. Further, when the difference is 10 [° C.] or more, it means that the crystalline polyester resin which was present in an incompatible state before heating (before the first temperature increase) and the polyester resin are heated. It means that after that (after the first temperature rise), a compatible state is achieved. The compatible state after heating does not have to be a complete compatible state.

  The melting point of the toner is appropriately selected depending on the intended purpose without any limitation, but it is preferably 60 [°C] or higher and 80 [°C] or lower.

The toner preferably has a storage elastic modulus at 50[° C.] of 1.0×10 ⁷ [Pa] or more. Further, it is desirable that the loss elastic modulus at 80 [° C.] is 8.0×10 ⁴ [Pa] or more and 5.0×10 ⁵ [Pa] or less. Further, it is desirable that the loss elastic modulus at 160[° C.] is 2.0×10 ² [Pa] or more and 3.0×10 ³ [Pa] or less.

The storage elastic modulus of 50[° C.] is a general temperature reached by the surface temperature of the developer carrier, the photoconductor, and their peripheral members in the image forming apparatus that has performed the continuous image forming operation. Is generally subjected to the developing step in this temperature range. If the toner is easily deformed in an environment of 50[° C.], the toners may aggregate in the developing section or may be fixed to the developer carrier, resulting in dot-like stains derived from toner aggregates on the image. White spots occur due to abnormal supply of toner to the photoconductor. In addition, heat resistant storage stability is reduced. Therefore, the toner is required to have a characteristic that it is difficult to be deformed at 50[° C.], and thus the storage elastic modulus at 50[° C.] is desired to be 1.0×10 ⁷ [Pa] or more. ..

By using a resin having a high glass transition temperature Tg as a base material resin or controlling the amount of a crystalline resin having a low elasticity, the storage elastic modulus at 50[° C.] of the toner is 1.0×10 ⁷ [. Pa] or higher.

On the other hand, in order to achieve excellent low-temperature fixability, it is desired that the loss elastic modulus of the toner be relatively low. Therefore, the loss elastic modulus at 80 [° C.] of the toner is desired to be 8.0×10 ⁴ [Pa] or more and 5.0×10 ⁵ [Pa] or less. In order to achieve excellent low temperature fixability, it is necessary to lower the melting temperature of the toner. The temperature of 80[° C.] is the temperature reached by the surface temperature of the developer carrier, the photoconductor, and their peripheral members when the continuous image forming operation is performed in a high temperature and high humidity environment. Therefore, in a relatively soft toner having a loss elastic modulus at 80 [° C.] of less than 5.0×10 ⁴ [Pa], the base resin is likely to be spent, which may cause a decrease in charge of the carrier over time.

The base resin of the toner contains the amorphous polyester resin A and the amorphous polyester resin B having a glass transition temperature of 40[° C.] or more and 70[° C.] or less, and thus good low temperature fixing can be achieved. Can be realized. Further, the amorphous polyester resin A and the amorphous polyester resin B are preferably compatible with each other. In addition, by controlling the characteristic values such as the molecular weight and the glass transition temperature of the amorphous polyester resin A and the compounding amount, and by controlling the characteristic values such as the melting point of the crystalline polyester resin C and the compounding amount, It becomes possible. That is, the loss elastic modulus at 80[° C.] of the toner can be set to 8.0×10 ⁴ [Pa] or more and 5.0×10 ⁵ [Pa] or less.

If the loss elastic modulus at 80 [° C.] of the toner is less than 8.0×10 ⁴ [Pa], the heat-resistant storage property is insufficient and the fluidity of the toner after storage and the machine (image forming apparatus) When heated, it solidifies and causes conveyance failure.

In order to secure high high-temperature offset resistance, a sufficiently wide fixing temperature range, and a sufficiently high toner spreadability in the fixing temperature range and to obtain excellent color reproducibility, the loss elastic modulus of 160 [° C.] of the toner is It is desirable to be 2.0×10 ² [Pa] or more and 3.0×10 ³ [Pa] or less. Note that, in general, at the time of fixing, it is considered that a temperature lower than the fixing temperature by about 20[° C.] is applied to the toner because heat is taken by a recording medium such as paper. A toner having a loss elastic modulus at 160 [° C.] of 2.0×10 ² [Pa] or more and 3.0×10 ³ [Pa] or less has, for example, a glass transition temperature in an ultra-low range and is melted. It can be preferably realized by using the amorphous polyester resin A which has high viscosity and is hard to flow.

If the loss elastic modulus at 160[° C.] is less than 2.0×10 ² [Pa], the temperature at which high-temperature offset occurs decreases, so that a sufficient fixing temperature range cannot be secured. Further, when the loss elastic modulus at 160 [° C.] exceeds 3.0×10 ³ [Pa], a wide fixing temperature range can be secured, but the spreadability of the toner becomes poor. The color gamut becomes narrow (that is, the color reproducibility decreases). The loss elastic modulus at 160[° C.] is particularly preferably 1.0×10 ³ [Pa] or less.

  The volume average particle diameter of the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3 [μm] or more and 7 [μm] or less. The ratio of the volume average particle diameter to the number average particle diameter is preferably 1.2 or less. Further, it is preferable to contain a component having a volume average particle diameter of 2 [μm] or less in an amount of 1 [number%] or more and 10 [number%] or less.

  The SP value, the glass transition temperature Tg, the acid value, the hydroxyl value, the molecular weight, and the melting point of the polyester resin, the crystalline polyester resin, and the release agent may be measured by themselves. It may be calculated as That is, by separating each component from an actual toner by gel permeation chromatography (GPC) and the like, and applying the analysis method described below to each of the obtained components, SP value, Tg, molecular weight, melting point, mass ratio of constituent components May be calculated.

  Separation of each component by GPC can be performed as follows, for example. That is, in GPC measurement using THF (tetrahydrofuran) as a mobile phase, the eluate is fractionated by a fraction collector or the like, and the fractions corresponding to the desired molecular weight portion in the total integral of the elution curve are collected. After the concentrated eluate is concentrated and dried by an evaporator or the like, the solid content is dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, and 1H-NMR measurement is performed. Calculate the constituent monomer ratios.

  Another method is to calculate the constituent monomer ratio by concentrating the eluate, hydrolyzing it with sodium hydroxide, etc., and qualitatively and quantitatively analyzing the decomposition products by high performance liquid chromatography (HPLC). be able to. When the toner production method is one in which toner base particles are formed while a polyester resin is produced by an elongation reaction and/or a crosslinking reaction of the non-linear reactive precursor and the curing agent, , May be done as follows. That is, each component may be separated from the actual toner by GPC or the like, and the glass transition temperature Tg of the separated polyester resin may be obtained. Alternatively, separately, a polyester resin may be synthesized by an elongation reaction and/or a cross-linking reaction between the non-linear reactive precursor and the curing agent, and the glass transition temperature Tg or the like may be measured from the synthesized polyester resin. ..

  The following method can be exemplified as a method of separating each component when analyzing the toner. That is, first, 1 [g] of toner is put into 100 [ml] of THF, and a solution containing soluble components is obtained while stirring for 30 minutes under the condition of 25 [°C]. This is filtered through a 0.2 [μm] membrane filter to obtain a THF-soluble component in the toner. Then, this is dissolved in THF to prepare a sample for GPC measurement, and the sample is injected into GPC used for measuring the molecular weight of each resin described above. On the other hand, a fraction collector is arranged at the eluate outlet of the GPC, and the eluate is collected at predetermined counts, and the eluate is collected every 5% in area ratio from the start of elution of the elution curve (rise of the curve). To get Then, for each eluate, 30 [mg] of sample is dissolved in 1 [ml] of deuterated chloroform, and 0.05 [vol %] of tetramethylsilane (TMS) is added as a reference substance. The solution was filled in a glass tube for NMR measurement having a diameter of 5 [mm], and a nuclear magnetic resonance apparatus (JNM-AL400 manufactured by JEOL Ltd.) was used for 128 times at a temperature of 23 [°C] to 25 [°C]. Accumulate and obtain spectrum. Various numerical values can be obtained for the monomer composition such as polyester resin and crystalline polyester resin contained in the toner, and the composition ratio from the peak integration ratio of the obtained spectrum.

Specifically, the peaks may be assigned as follows, and the component ratio of the constituent monomers may be determined from the respective integral ratios. That is, the attribution of peaks is as follows, for example.
・Around 8.25 [ppm]: derived from the benzene ring of trimellitic acid (for one hydrogen)
-Around 8.07 [ppm] to 8.10 [ppm]: Derived from the benzene ring of terephthalic acid (for 4 hydrogens)
・Around 7.1 [ppm] to 7.25 [ppm]: derived from the benzene ring of bisphenol A (4 hydrogens)
・Around 6.8 [ppm]: Origin of benzene ring of bisphenol A (4 hydrogens) and double bond of fumaric acid (2 hydrogens)
-Around 5.2 [ppm] to 5.4 [ppm]: bisphenol A propylene oxide adduct derived from methine (one hydrogen)
-Around 3.7 [ppm] to 4.7 [ppm]: bisphenol A propylene oxide adduct derived from methylene (2 hydrogens) and bisphenol A ethylene oxide adduct derived from methylene (4 hydrogens)
・1.6 [around ppm]: Derived from the methyl group of bisphenol A (for 6 hydrogens)

  From these results, for example, the extract recovered in the fraction in which 90% or more of the polyester resin having the structure represented by the above-mentioned chemical formula can be treated as the polyester resin having the structure represented by the same chemical formula. Similarly, the extract recovered in the fraction in which the other polyester resin accounts for 90% or more can be treated as the other polyester resin. Further, the extract recovered in the fraction in which the crystalline polyester resin accounts for 90% or more can be treated as the crystalline polyester resin.

  The THF insoluble matter of the toner can be extracted, for example, as follows. That is, 1 part by weight of toner is added to 40 parts by weight of THF and refluxed for 6 hours, and then the insoluble component is precipitated by a centrifugal separator to separate the insoluble component and the supernatant liquid. The insoluble component is dried at 40[° C.] for 20 hours to obtain a THF insoluble matter. The THF-insoluble matter corresponds to a non-linear polyester resin. Therefore, the THF-insoluble matter has a plurality of structural portions derived from trivalent isocyanate.

The composition in the THF-insoluble matter can be analyzed by X-ray diffraction, GC/MS, LC/MS, IR measurement, etc. in addition to NMR measurement by a solution or solid. Simply, it can be analyzed by the pyrolysis simultaneous methylation GC-MS method using a methylation reaction reagent, for example, under the following conditions.
・Device name: Shimadzu QP2010 Frontier Lab Py2020D
・Data analysis software: Shimadzu's GCMSsolution
・Heating temperature: 280℃
・Reaction thermal decomposition temperature: 300℃
・Column name: Ultra ALLOY-5 L=30 [m], ID=0.25 [mm], Film=0.25 [μm]
-Temperature bath temperature: 50°C (holding 1 minute) to 10°C/min to 330°C (holding 11 minutes)
-Carrier gas: constant at 53.6 [kPa], He 1.0 [ml/min]
・Injection mode: Split (1:100)
・Ionization method: EI method (70 eV)
・Measurement mode: Scan mode ・Library: NIST 20 MASS SPECTRAL

The hydroxyl value of the resin can be measured using a method based on JIS K0070-1966. Specifically, first, 0.5 [g] of the sample is precisely weighed in a 100 [ml] volumetric flask, and 5 [ml] of the acetylating reagent is added thereto. Next, after heating in a warm bath of 100±5° C. for 1 to 2 hours, the flask is taken out of the warm bath and allowed to cool. Further, water is added and shaken to decompose acetic anhydride. Next, in order to completely decompose acetic anhydride, the flask is again heated in a warm bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. Furthermore, the hydroxyl value is measured at 23[° C.] using an automatic potentiometric titrator DL-53 Titortor (manufactured by METTLER TOLEDO) and an electrode DG113-SC (manufactured by METTLER TOLEDO). Then, analysis is performed using LabX Light Version 1.00.000. For the calibration of the device, a mixed solvent of toluene 120 [ml] and ethanol 30 [ml] is used. At this time, the measurement conditions are as follows.
・Stir Speed: 25 [%]
・Time: 15 [s]
・EQP titration titrant/sensor titrant CH3ONa
・Concentration: 0.1 [mol/l]
・Sensor DG115
・Unit of measurement mV
・Predispensing to volume: 1.0 [ml]
・Wait time [s] 0
・Tirant addition Dynamic
・DE(set): 8.0 [mV]
・DV (min): 0.03 [mL]
-DV (max) [mL] 0.5
・Measure mode Equilibrium controlled
・DE [mV] 0.5
・DT[s] 1.0
・T(min) [s] 2.0
・T(max) [s] 20.0
・Recognition Threshold 100.0
・Steepest jump only No
・Range No
・Tendency None
-Termination at maximum volume [mL] 10.0
・At potential No
・At slope No
・After number EQPs Yes n=1
-Comb. termination conditions No
・Evaluation Procedure Standard
・Potential1 No
・Potential2 No
・Stop for revaluation No

  Further, the acid value can be measured by using a method according to JIS K0070-1992. Specifically, first, 0.5 [g] of a sample (0.3 g of ethyl acetate-soluble content) is added to 120 [ml] of toluene and dissolved by stirring at 23° C. for about 10 hours. Next, 30 [ml] of ethanol is added to obtain a sample solution. If the sample does not dissolve, use a solvent such as dioxane or tetrahydrofuran. Further, using an automatic potentiometric titrator DL-53 Titortor (manufactured by METTLER TOLEDO) and an electrode DG113-SC (manufactured by METTLER TOLEDO), the acid value was measured at 23[° C.], and the analysis software LabX Light Version 1 was used. Analyze using 0.0000. A mixed solvent of toluene 120 [ml] and ethanol 30 [ml] is used for the calibration of the device. At this time, the measurement conditions are the same as those for the above hydroxyl value.

  In addition, titration was performed with a previously standardized 0.1N potassium hydroxide/alcohol solution, and from the titer, acid value [mgKOH/g]=titer [mL]×N×56.1 [mg/mL]/sample [ g] (N is a factor of 0.1 N potassium hydroxide/alcohol solution) to calculate the acid value.

  The melting point and glass transition temperature Tg of a substance can be measured using, for example, a DSC system (differential scanning calorimeter) (“Q-200”, manufactured by TA Instruments). Specifically, the melting point and glass transition temperature Tg of the target sample are measured as follows. First, about 5.0 [mg] of the target sample is put in a sample container made of aluminum, the sample container is placed on a holder unit, and set in an electric furnace. Then, in a nitrogen atmosphere, heating is performed from −80 [° C.] to 150 [° C.] at a temperature increase rate of 10 [° C./min] (first temperature increase). Then, the temperature is decreased from 150 [°C] to -80 [°C] at a temperature decrease rate of 10 [°C/min], and further heated to 150 [°C] at a temperature increase rate of 10 [°C/min] (second temperature increase). To do. In each of the first temperature increase and the second temperature increase, a DSC curve is measured using a differential scanning calorimeter (“Q-200”, manufactured by TA Instruments). From the obtained DSC curve, a DSC curve at the time of the first temperature rise can be selected by using an analysis program in the Q-200 system, and the glass transition temperature of the target sample at the first temperature rise can be determined. Similarly, the DSC curve at the time of the second temperature increase can be selected to determine the glass transition temperature of the target sample at the second temperature increase.

  Further, from the obtained DSC curve, a DSC curve at the time of the first heating is selected using an analysis program in the Q-200 system, and the endothermic peak top temperature at the first heating of the target sample is determined as the melting point. You can Similarly, a DSC curve at the time of the second temperature increase can be selected and the endothermic peak top temperature at the second temperature increase of the target sample can be obtained as the melting point.

  When the toner is used as the target sample, the glass transition temperature at the first temperature increase is Tg1st, and the glass transition temperature at the second temperature increase is Tg2nd. Regarding the glass transition temperature Tg and melting point of other constituent components such as polyester resin, crystalline polyester resin, release agent, etc., unless otherwise specified, the endothermic peak top temperature and the glass transition temperature at the time of the second temperature increase are The melting point and glass transition temperature Tg of the target sample are used.

Regarding the volume average particle diameter (D4), number average particle diameter (Dn), and ratio (D4/Dn) of the two, for example, Coulter Counter TA-II, Coulter Multisizer II (both manufactured by Coulter, Inc.), etc. Can be used for measurement. In the present invention, the value using Coulter Multisizer II is defined as the volume average particle diameter (D4) or the number average particle diameter (Dn). The measuring methods are as follows. First, a surfactant (preferably polyoxyethylene alkyl ether (nonionic surfactant)) as a dispersant is added in an amount of 0.1 [ml] to 5 [ml] in 100 [ml] to 150 [ml] of an electrolytic aqueous solution. ] Add The electrolytic aqueous solution is a 1 mass% NaCl aqueous solution prepared using first-grade sodium chloride, and for example, ISOTON-II (manufactured by Coulter, Inc.) can be used. Add 2 [mg] to 20 [mg] of the measurement sample. The electrolytic aqueous solution in which the sample is suspended is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. After that, the volume and the number of the toner particles or the toner are measured by the above-mentioned measuring device using the aperture of 100 [μm], and the volume distribution and the number distribution are calculated. The volume average particle diameter (D4) and the number average particle diameter (Dn) of the toner are calculated from the obtained distributions. The channels listed below are targeted.
-2.00 μm or more and less than 2.52 μm-2.52 μm or more and less than 3.17 μm-3.17 μm or more and less than 4.00 μm-4.00 μm or more and less than 5.04 μm-5.04 μm or more and less than 6.35 μm・6.35 µm or more and less than 8.00 µm ・8.00 µm or more and less than 10.08 µm ・10.08 µm or more and less than 12.70 µm ・12.70 µm or more and less than 16.00 µm ・16.00 µm or more but less than 20.20 µm・20.20 μm or more and less than 25.40 μm ・25.40 μm or more and less than 32.00 μm ・Using 13 channels of 32.00 μm or more and less than 40.30 μm, particles having a particle size of 2.00 μm or more and less than 40.30 μm Target.

The molecular weight of each component of the toner can be measured, for example, as follows.
The measurement conditions are as listed below.
-Gel permeation chromatography (GPC) measuring device: GPC-8220GPC (manufactured by Tosoh Corporation)
・Column: TSKgel Super HZM-H 15 cm triplet (manufactured by Tosoh Corporation)
Temperature: 40 [℃]
・Solvent: Tetrahydrofuran (THF)
・Flow rate: 0.35 [ml/min]
-Sample: Inject 0.4 [ml] sample of 0.15 [mass%]-Pretreatment of sample: Dissolve toner in tetrahydrofuran THF (stabilizer-containing Wako Pure Chemical Industries) at 0.15 [mass%] , Filtered with 0.2 [μm] filter

The THF sample solution is injected by 100 [μl] and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, Showdex STANDARD Std. No S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, S-0.580 are used. An RI (refractive index) detector is used as the detector.

  The storage elastic modulus (G′) and loss elastic modulus (G″) of the toner can be measured using, for example, a dynamic viscoelasticity measuring device (ARES, manufactured by TA Instruments). is there. The frequency at the time of measurement is 1 [Hz]. The measurement sample is molded into a pellet shape having a diameter of 8 [mm] and a thickness of 1 [mm] to 2 [mm], and fixed on a parallel plate having a diameter of 8 [mm]. Then, from a state of being stabilized at 40[° C.], a temperature rising rate of 2.0[° C.] up to 200[° C.] at a frequency of 1 Hz (6.28 rad/s) and a strain amount of 0.1% (strain amount control mode). /Min] and the storage elastic modulus and loss elastic modulus are measured.

  In the low temperature range of 40 to 50[° C.], the adhesion between the toner and the device is insufficient, and the toner may slip at the start of measurement, and the elastic modulus may be measured lower than it should be. In such a case, the elastic modulus may seem to increase as the temperature rises, but this is not an accurate value. Therefore, it is necessary to measure the elastic modulus in the low temperature region by raising the temperature to 55 to 60[° C.] to bring the toner and the measuring device into close contact with each other and then lowering the temperature to the measurement start temperature.

  The method for producing the toner is not particularly limited and may be appropriately selected depending on the intended purpose. The toner contains a polyester resin and a crystalline polyester resin. Further, if necessary, it is preferable to granulate by dispersing an oil phase containing the release agent, the colorant and the like in an aqueous medium. In particular, it is more preferable that the polyester resin contains two types of polyester resins, that is, the polyester resin having the structure represented by the above chemical formula and the other polyester resin. Further, the toner preferably contains, as a polyester resin, the polyester prepolymer (reaction product of a reaction product of the polyester portion of R2 in the above chemical formula and the polyisocyanate, that is, a reaction precursor to be reacted with a curing agent). Furthermore, it is preferable that the polyester resin contains the other polyester resin having no urethane bond or urea bond. Further, if necessary, it is preferable to granulate by dispersing an oil phase containing the curing agent, the release agent, the colorant and the like in an aqueous medium.

  As a method for producing such a toner, a known dissolution suspension method can be mentioned. As an example of a method for producing a toner, a method of forming base material particles while producing a polyester resin having a structure represented by the above chemical formula by an elongation reaction and/or a crosslinking reaction between the polyester prepolymer and the curing agent is described. explain. In such a method, the aqueous medium is prepared, the oil phase containing the toner material is prepared, the toner material is emulsified or dispersed, and the organic solvent is removed.

  The aqueous medium can be prepared, for example, by dispersing resin particles in the aqueous medium. The amount of the resin particles added to the aqueous medium is not particularly limited and may be appropriately selected depending on the intended purpose, but is 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the aqueous medium. Preferably.

  The aqueous medium is appropriately selected depending on the intended purpose without any limitation, and examples thereof include water, a solvent miscible with water, and a mixture thereof. These may be used alone or in combination of two or more. Of these, water is preferred.

  The solvent miscible with water is appropriately selected depending on the intended purpose without any limitation, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, and lower ketones. The alcohol is appropriately selected depending on the intended purpose without any limitation, and examples thereof include methanol, isopropanol, and ethylene glycol. The lower ketones are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include acetone and methyl ethyl ketone.

  The oil phase containing the toner material can be prepared as follows. That is, a toner material containing at least the polyester prepolymer, the other polyester resin, and the crystalline polyester resin, and further containing the curing agent, the release agent, the colorant, and the like, is used as an organic material. Dissolve or disperse in a solvent.

  The organic solvent is appropriately selected depending on the intended purpose without any limitation, but it is preferably an organic solvent having a boiling point of less than 150 [°C] from the viewpoint of easy removal. The organic solvent having a boiling point of less than 150[° C.] is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform and monochlorobenzene. Alternatively, it may be dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, or the like. These may be used alone or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is more preferable.

  The emulsification or dispersion of the toner material can be performed by dispersing an oil phase containing the toner material in the aqueous medium. Then, when the toner material is emulsified or dispersed, the curing agent and the polyester prepolymer are subjected to an elongation reaction and/or a crosslinking reaction to generate a polyester resin having a structure represented by the above chemical formula. The polyester resin having the structure represented by the above chemical formula can be produced, for example, by any of the following methods (1) to (3).

(1) An oil phase containing the polyester prepolymer and the curing agent is emulsified or dispersed in an aqueous medium, and the curing agent and the polyester prepolymer are allowed to undergo an elongation reaction and/or a crosslinking reaction in the aqueous medium. As a result, a polyester resin having the structure represented by the above chemical formula is produced.
(2) The oil phase containing the polyester prepolymer is emulsified or dispersed in an aqueous medium to which the curing agent has been added in advance, and the curing agent and the polyester prepolymer undergo an elongation reaction and/or a crosslinking reaction in the aqueous medium. Let As a result, a polyester resin having the structure represented by the above chemical formula is produced.
(3) After the oil phase containing the polyester prepolymer is emulsified or dispersed in an aqueous medium, the curing agent is added to the aqueous medium, and the curing agent and the polyester prepolymer are added from the particle interface in the aqueous medium. And elongation reaction and/or crosslinking reaction. As a result, a polyester resin having the structure represented by the above chemical formula is produced.

  When the curing agent and the polyester prepolymer are subjected to an elongation reaction and/or a crosslinking reaction from the particle interface, a polyester resin having a structure represented by the above chemical formula is preferentially formed on the surface of the resulting toner. Thereby, a concentration gradient of the polyester resin having the structure represented by the above chemical formula can be provided in the toner.

  The reaction conditions (reaction time, reaction temperature) for producing the polyester resin having the structure represented by the chemical formula are not particularly limited, and may be appropriately selected depending on the combination of the curing agent and the polyester prepolymer. You can choose. The reaction time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 minutes to 40 hours, more preferably 2 hours to 24 hours. The reaction temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0 [°C] to 150 [°C], more preferably 40 [°C] to 98 [°C].

  The method for stably forming the dispersion containing the polyester prepolymer in the aqueous medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the method include adding an oil phase prepared by dissolving or dispersing a. The disperser for the dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include low-speed shearing dispersers, high-speed shearing dispersers, friction dispersers, and high-pressure jet dispersers. Examples thereof include a disperser and an ultrasonic disperser. Among these, the high-speed shearing disperser is preferable in that the particle size of the dispersion (oil droplets) can be controlled to 2 [μm] to 20 [μm]. When this high-speed shearing disperser is used, conditions such as the number of revolutions, dispersion time, dispersion temperature, etc. can be appropriately selected according to the purpose. The number of revolutions is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1,000 [rpm] to 30,000 [rpm], and 5,000 [rpm] to 20,000 [rpm]. rpm] is more preferable. The dispersion time is appropriately selected depending on the intended purpose without any limitation, but it is preferably 0.1 minutes to 5 minutes in the case of a batch method. The dispersion temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0 [°C] to 150 [°C] and 40 [°C] to 98 [°C] under pressure. Is more preferable. Generally, the higher the dispersion temperature, the easier the dispersion.

  The amount of the aqueous medium used when emulsifying or dispersing the toner material is not particularly limited and can be appropriately selected according to the purpose. The amount is preferably 50 parts by mass to 2,000 parts by mass, more preferably 100 parts by mass to 1,000 parts by mass, relative to 100 parts by mass of the toner material. If the amount of the aqueous medium used is less than 50 parts by mass, the dispersed state of the toner material may deteriorate, and toner base particles having a predetermined particle size may not be obtained. If it exceeds 2,000 parts by mass, the production cost may increase.

  When emulsifying or dispersing the oil phase containing the toner material, it is preferable to use a dispersant from the viewpoint of stabilizing the dispersion such as oil droplets, forming a desired shape and sharpening the particle size distribution. .. The dispersant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include surfactants, sparingly water-soluble inorganic compound dispersants, and polymeric protective colloids. These may be used alone or in combination of two or more. Among these, the surfactant is preferable. The surfactant is appropriately selected depending on the intended purpose without any limitation, and examples thereof include anionic surfactant, cationic surfactant, nonionic surfactant, and amphoteric surfactant. be able to. The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, alkylbenzene sulfonate, α-olefin sulfonate, phosphoric acid ester and the like can be mentioned. Among these, those having a fluoroalkyl group are preferable.

  A catalyst can be used in the elongation reaction and/or the crosslinking reaction when forming the polyester resin having the structure represented by the above chemical formula. The catalyst is appropriately selected depending on the intended purpose without any limitation, and examples thereof include dibutyltin laurate and dioctyltin laurate.

  The method for removing the organic solvent from the dispersion liquid such as the emulsified slurry is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of gradually raising the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, a method of spraying the dispersion liquid in a dry atmosphere to remove the organic solvent in the oil droplets, and the like can be mentioned. When the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, etc., and further classified. The classification may be carried out by removing a fine particle portion by a cyclone, a decanter, a centrifugal separator or the like in a liquid, or a classification operation may be carried out after drying. The obtained toner base particles may be mixed with particles such as the external additive and the charge control agent. At this time, by applying a mechanical impact force, it is possible to suppress detachment of the particles of the external additive or the like from the surface of the toner base particles.

  The method of applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of applying an impact force to the mixture using a blade rotating at high speed, a method of introducing the mixture into a high-speed air stream and accelerating the particles to collide the particles with each other or a suitable collision plate may be mentioned. The device used in these methods is not particularly limited and can be appropriately selected according to the purpose. For example, an Ong mill (manufactured by Hosokawa Micron), a type I mill (manufactured by Nippon Pneumatic Co., Ltd.) that reduces the grinding air pressure, a hybridization system (manufactured by Nara Machinery Co., Ltd.), a cryptotron system (Kawasaki Heavy Industries, Ltd.) Manufactured), automatic mortar and the like.

  When the above toner (low-temperature fixing toner) is used, a spent layer of toner is formed and grows on the surface of the carrier, whereby the toner charging performance of the carrier is likely to decrease with time. For this reason, conventionally, in a developing device using a low-temperature fixing toner, it is general to devise to reduce the stress applied to the carrier as much as possible.

  FIG. 5 is a configuration diagram showing a low-stress developing device 5'of a first example which, unlike the copying machine according to the embodiment, applies relatively weak stress to the internal carrier. The low-stress developing device 5'is provided in the casing 60 at a position close to the doctor blade 51 and at a position upstream of the doctor blade 51 in the sleeve rotation direction so as to considerably reduce the volume of the space. The shape has been devised. At the above-mentioned position, the developer regulated by the doctor blade 51 stays while rotating around the sleeve with vigorous rotation, so that a strong stress is applied to the carrier. In order to considerably reduce the amount of the developer to which such a strong stress is applied, the volume of the space at the above position is considerably reduced.

  FIG. 6 is a block diagram showing a second example of a low stress developing device 5″, which is different from the copying machine according to the embodiment in that it applies relatively weak stress to the internal carrier. The developing device 5″ uses a fifth magnetic pole P5 having a considerably weak magnetic force to reduce the stress applied to the developer. The magnetic force of the fifth magnetic pole P5 in the copying machine according to the embodiment is 72 [mT], while the magnetic force of the fifth magnetic pole P5 in the low stress developing device 5″ is 55 [mT].

  In these low-stress developing devices, the spent of the low-temperature fixing toner on the surface of the carrier can be suppressed to a certain extent. However, when the temperature inside the apparatus becomes high during continuous image forming operation, the low-temperature fixing toner is spent. For this reason, it is not possible to reliably prevent the deterioration of the toner charging performance of the carrier due to the spent low temperature fixing toner on the surface of the carrier.

  Next, a characteristic configuration of the copying machine according to the embodiment will be described. The carrier used in the copying machine is one in which the surface of a particle core material is coated with a resin coating layer in which fine particles made of a substance having an electronegativity of 1.4 or less are dispersed.

FIG. 7 is an enlarged sectional view partially showing the magnetic carrier in the initial state set in the developing device 5. On the surface of the core _{C a1,} the resin coating layer _{C a2} is covered, the chargeable fine particles _{C a3} are dispersed in the resin coat layer _{C a2.} Most of the carrier surface is the resin coating layer C _a2 , and the chargeable fine particles C _a3 are barely exposed on the surface. Therefore, the chargeability of the resin coat layer C _a2 mainly contributes to the chargeability of the toner.

The element used as the electrostatic fine particles C _a3 has an electronegativity as described in “Japan Imaging Society (2008), “Chemical Toner” (series “Digital Printer Technology”) p77-78, Tokyo Denki University Press. Is smaller, the positive chargeability tends to be higher. The electronegativity includes Pauling's electronegativity, all-red roach's electronegativity, Mulliken's electronegativity, and the like, but in this specification, Pauling's electronegativity is used to _measure the chargeable fine particles C _a3 . Consider the chargeability. Details of Pauling's electronegativity are described in detail in the following documents. L. Pauling, “The Nature of the Chemical Bond”, Cornell University Press (1960); Masao Koizumi, “Chemical Bond Theory”, Kyoritsu Shuppan (1962).

FIG. 8 shows a Pauling electronegativity table. Here, silica and titanium oxide are often used as additives for toner, and silicon contained in these has electronegativity of 1.8 and titanium has electronegativity of 1.5. A resin material generally used as a base material resin for toner also has an electronegativity of 1.5 or more. On the other hand, in the reversal development method, toner is generally negatively charged by friction. Therefore, it is necessary that the carrier has a positive chargeability with respect to the base resin and additives of the toner. Therefore, as the chargeable fine particles C _a3 , one made of a substance having an electronegativity of 1.4 or less is used. There is. Examples of such substances include lithium, sodium, magnesium, potassium, calcium, scandium, rubidium and strontium. Further, yttrium, zirconium, cesium, barium, hafnium, francium, radium, various lanthanoids, various actinoids and the like may be used. By configuring the chargeable fine particles C _a3 with these, it is possible to frictionally charge the toner to a negative polarity by friction with the chargeable fine particles C _a3 .

From the viewpoints of environmental safety and availability (cost, quantity, etc.), among the chargeable fine particles C _a3 made of the above-mentioned substances, compounds containing magnesium oxide, magnesium hydroxide, barium sulfate, magnesium (hydrotalcite) Those consisting of are preferred. In any of them, the toner can be charged well. From the viewpoint of environmental stability, hydrotalcite and barium sulfate are particularly suitable.

The chargeable fine particles C _a3 may be used as they are, but may be one in which a conductive layer is provided under the resin coat layer C ^a2 to adjust the electric resistance. As a substance forming the conductive layer, indium tin oxide (ITO), phosphorus-doped tin (PTO), tungsten-doped tin (WTO), or the like can be used. In the case of phosphorus-doped tin (PTO), in order to obtain a desired resistance value, the conductive layer must be thicker than indium tin oxide (ITO) or tungsten-doped tin (WTO). The stress required to expose is relatively high. Therefore, indium tin oxide (ITO) or tungsten-doped tin (WTO) is preferable. Furthermore, tungsten-doped tin (WTO) is most preferable in terms of cost and availability (rare metal-less).

  As a method for uniformly depositing the salt hydrate layer of tin, for example, in the case of WTO, the following method may be used. First, a tungsten salt (tungsten chloride, tungsten oxychloride, sodium tungstate, tungstic acid, etc.) is prepared. In addition, tin salts (tin salts such as tin chloride, tin sulfate, and tin nitrate, stannates such as sodium stannate and potassium stannate, and organic tin compounds such as tin alkoxide) are also prepared. Then, an acidic aqueous solution in which those salts are dissolved, and a pH adjusting agent (basic aqueous solution) for depositing and depositing the dropped tungsten and tin in the form of hydrate on the surface of the pigment particles are charged fine particles. Are simultaneously added dropwise to the dispersed aqueous solution. As a result, it is possible to carry out the process while preventing the chargeable fine particles from being dissolved or surface-modified by an acid or an alkali. When indium tin oxide (ITO) or phosphorus-doped tin (PTO) is used, the above-mentioned tungsten may be replaced with phosphorus/indium. Of course, the treatment method is not limited to these as long as it can have conductivity.

As another method of adjusting the electric resistance of the carrier, a method of dispersing conductive fine particles in the coating resin may be adopted in addition to the charging fine particles C _a3 . Specifically, the low resistance material may be dispersed in the coating resin. Examples of the low resistance material include conductive polymers such as carbon, phosphorus-doped tin (PTO), tungsten-doped tin (WTO), indium tin oxide (ITO), tin oxide, zinc oxide, and polyaniline. Of these, tungsten-doped tin (WTO), indium tin oxide (ITO), and tin oxide are preferable from the viewpoint of not inhibiting charging with time. Further, tungsten-doped tin (WTO) or tin oxide is preferable from the viewpoint of cost and availability (rare metal-less).

A resistance may be adjusted by providing a conductive layer on the surface of the chargeable fine particles C _a3 . In this case, titanium oxide, alumina, silica, zinc oxide and the like can be cited as the substance constituting the inorganic fine particles, and alumina is particularly preferable. Indium tin oxide (ITO), tungsten-doped tin (WTO), and phosphorus-doped tin (PTO) can be used as the material forming the conductive layer. Tungsten-doped tin (WTO) or phosphorus-doped tin (PTO) is preferable in terms of cost and availability. As the method for providing the conductive layer on the inorganic fine particles, the same method as the method for providing the conductive layer on the surface of the above-mentioned chargeable fine particles can be used. Two or more types of chargeable fine particles C _a3 may be used in combination.

The particle size of the chargeable fine particles C _a3 is preferably 300 [nm] or more and 900 [nm] or less. Or the chargeable fine particles C _a3 to expose partially protruded on the surface of the resin coating layer C _a2 is the particle size of the charged particles C _a3, larger than the thickness of the resin coating layer C _a2, Even if it is made small, it must be close to the thickness. In the latter case, the chargeable fine particles C _a3 are barely exposed on the carrier surface in the initial _stage, but the exposure rate of the chargeable fine particles C _a3 increases as the resin coat layer C _a2 is scraped. ..

When the particle size of the charging fine particles C _a3 is less than 300 [nm], the height of the fine particles exposed from the surface of the resin coating layer C _a2 becomes insufficient, and even if a strong stress is applied to the carrier in the developing device. It becomes difficult for the chargeable fine particles C _a3 to be exposed on the carrier surface. As a result, it becomes impossible to sufficiently suppress the deterioration of the toner charging performance of the carrier with time. Further, if the height is not sufficient, the entire carrier may be covered with the spent layer of toner.

If the particle size of the charging fine particles C _a3 exceeds 900 [nm], the average particle size of the charging particles C _a3 becomes too large with respect to the average particle size of the carrier (20 to 50 μm), and the charging particles C _It becomes easy for _a3 to separate from the carrier. As a result, it becomes difficult to sufficiently suppress the deterioration of the toner charging performance of the carrier with time.

The particle size of the chargeable fine particles C _a3 can be measured as follows. First, the carrier is mixed with an embedding resin (manufactured by Devcon, two-liquid mixture, 30-minute curing type epoxy resin), left overnight to be cured, and mechanically polished to prepare a rough cross-section sample. A cross section polisher (SM-09010 manufactured by JEOL) is used for this, and the cross section is finished under the conditions of an acceleration voltage of 5.0 [kV] and a beam current of 120 [μA]. Then, an image is taken with a scanning electron microscope (Merlin manufactured by Carl Zeiss) under the conditions of an acceleration voltage of 0.8 [kV] and a magnification of 30,000 times. The photographed image is captured in the TIFF format, and the equivalent circle diameter of 100 particles of the charged fine particles C _a3 is measured by using Image-Pro Plus manufactured by Media Cybernetics, and the average value is obtained. The result is _{defined as} the particle size of the chargeable fine particles C _a3 .

In order to adjust the chargeability of the carrier in the initial state and to stably disperse the chargeable fine particles C _a3 , it is desirable to include an aminosilane coupling agent in the resin material of the resin coat layer C _a2 . This is because the initial chargeability (charge in a state where no scraping or spent is generated) can be adjusted by the amount of the aminosilane coupling agent. The addition amount of the aminosilane coupling agent is preferably 0.1 to 10 [wt%] with respect to the weight of the resin coat layer _Ca2 .

  The type of aminosilane coupling agent is not particularly limited. Examples thereof include r-(2-aminoethyl)aminopropyltrimethoxysilane, r-(2-aminoethyl)aminopropylmethyldimethoxysilane, and r-methacryloxypropyltrimethoxysilane. N-β-(N-vinylbenzylaminoethyl)-r-aminopropyltrimethoxysilane hydrochloride, r-glycidoxypropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane And so on. Further, vinyltriacetoxysilane, r-chloropropyltrimethoxysilane, hexamethyldisilazane, r-anilinopropyltrimethoxysilane, vinyltrimethoxysilane and the like may be used. Further, octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride, r-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, allyltriethoxysilane, etc. may be used. Further, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, dimethyldiethoxysilane, 1,3-divinyltetramethyldisilazane, etc. may be used. Further, methacryloxyethyl dimethyl(3-trimethoxysilylpropyl) ammonium chloride or the like may be used. Two or more of these may be used in combination.

  Examples of commercially available silane coupling agents include AY43-059, SR6020, SZ6023, SH6026, SZ6032, SZ6050, AY43-310M, SZ6030, SH6040, AY43-026 and the like. Moreover, AY43-031, sh6062, Z-6911, sz6300, ss6075, sz6079, sz6083, sz6070, sz6072, Z-6721, AY43-004, Z-6187, AY43-021, AY43-043, etc. may be used. Also, AY43-040, AY43-047, Z-6265, AY43-204M, AY43-048, Z-6403, AY43-206M, AY43-206E, Z6341, AY43-210MC, AY43-083, AY43-101 and the like may be used. .. Moreover, AY43-013, AY43-158E, Z-6920, Z-6940, etc. may be used. Both are manufactured by Toray Silicone Co., Ltd.

  The volume average particle diameter of the carrier is preferably 20 [μm] to 50 [μm]. When the volume average particle size of the carrier is less than 20 [μm], the magnetization per particle becomes weak, and carrier adhesion may occur. If it exceeds 50 [μm], it becomes difficult to obtain a high-resolution image. The volume average particle diameter of the carrier can be measured using an SRA type of Microtrac particle size analyzer (manufactured by Nikkiso Co., Ltd.). It is possible to use the one which is set in the range of 0.7 [μm] or more and 125 [μm] or less. Further, methanol is used for the dispersion liquid, and the refractive index of methanol is set to 1.33 and the refractive index of the carrier and the core material is set to 2.42.

The content ratio of the charged particles _{C a3} in the resin coat layer _{C a2} is 20 wt% or more with respect to the weight of the resin coating layer _{C a2,} is preferably 70 wt% or less. When the content ratio is less than 20% by weight, the amount of the chargeable fine particles C _a3 is insufficient, and it becomes impossible to obtain a sufficient charging ability during the toner spent. If the content of the chargeable fine particles _{C a3} exceeds 70 wt%, the charged particles _{C a3} in the resin coat layer _{C a2} is excessive. As a result, a sufficient binding force cannot be obtained and the chargeable fine particles C _a3 are easily peeled off, so that the carrier is easily attached to the photoconductor 1.

式中で、Ｒ１は水素原子またはメチル基を示し、Ｒ２は炭素原子数１〜４のアルキル基を示す。また、ｍは１〜８の整数を示し、Ｘは１０〜９０モル％を示す。

式中で、Ｒ１は水素原子またはメチル基を示し、Ｒ２は炭素原子数１〜４のアルキル基を示し、Ｒ３は炭素原子数１〜８のアルキル基、または炭素原子数１〜４のアルコキシ基を示し、ｍは１〜８の整数を示し、Ｙは１０〜９０モル％を示す。 The resin coat layer C _a2 contains a repeating unit (A part) represented by the following chemical _formula 1 and a repeating unit (B part) represented by the following chemical _{formula 2, and} is an acrylic resin obtained by radical copolymerization. It is desirable that the resin is obtained by heat-treating the copolymer.

In the formula, R1 represents a hydrogen atom or a methyl group, and R2 represents an alkyl group having 1 to 4 carbon atoms. Moreover, m shows the integer of 1-8 and X shows 10-90 mol%.

In the formula, R1 represents a hydrogen atom or a methyl group, R2 represents an alkyl group having 1 to 4 carbon atoms, R3 is an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. , M represents an integer of 1 to 8, and Y represents 10 to 90 mol %.

  The portion A contains a monomer component (monomer A component) that produces the repeating unit represented by Chemical formula 2. Further, the B portion contains a monomer component (monomer B component) that produces the repeating unit represented by Chemical formula 2. In the A portion (and the monomer A component), X is 10 to 90 [mol %], and more preferably 30 to 70 [mol %]. In the portion B (and the monomer A component), X=10 to 90 [mol %], and more preferably 30 to 70 [mol %].

  The A portion (monomer A component) has an atomic group having a large number of methyl groups in its side chain; tris(trimethylsiloxy)silane. When the ratio of the A portion (monomer A component) to the entire resin becomes high, the surface energy of the coating layer on the carrier core material (core material particles) becomes small, and the resin component of the toner, the wax component, etc. adhere to each other. Less. When the A portion (monomer A component) is less than 10 [mol %], a sufficient effect of reducing the surface energy cannot be obtained, and the adhesion of the toner component rapidly increases. On the other hand, when the A portion (monomer A component) is more than 90 [mol %], the toughness due to the effect of the B portion (monomer B component) becomes insufficient, and the adhesiveness between the core material particles and the coating layer decreases, The durability of the carrier film (coating layer) deteriorates.

R2 in the formulas of chemical formulas 1 and 2 is an alkyl group having 1 to 4 carbon atoms, and the monomer A component that produces such an A portion is not limited, but for example, the following are listed. An example is a tris(trialkylsiloxy)silane compound represented by a chemical formula. In the formula, Me is a methyl group, Et is an ethyl group, and Pr is a propyl group.
_{· CH 2 = CMe-COO-} C 3 H 6 -Si (OSiMe 3) 3
_{· CH 2 = CH-COO-} C 3 H 6 -Si (OSiMe 3) 3
_{· CH 2 = CMe-COO-} C 4 H 8 -Si (OSiMe 3) 3
_{· CH 2 = CMe-COO-} C 3 H 6 -Si (OSiEt 3) 3
_{· CH 2 = CH-COO-} C 3 H 6 -Si (OSiEt 3) 3
_{· CH 2 = CMe-COO-} C 4 H 8 -Si (OSiEt 3) 3
_{· CH 2 = CMe-COO-} C 3 H 6 -Si (OSiPr 3) 3
_{· CH 2 = CH-COO-} C 3 H 6 -Si (OSiPr 3) 3
_{· CH 2 = CMe-COO-} C 4 H 8 -Si (OSiPr 3) 3

  The method for producing the monomer component A for producing the A portion is not particularly limited, but, for example, a method of reacting tris(trialkylsiloxy)silane with allyl acrylate or allyl methacrylate in the presence of a platinum catalyst can be exemplified. .. Further, a method of reacting methacryloxyalkyltrialkoxysilane and hexaalkyldisiloxane in the presence of a carboxylic acid and an acid catalyst described in JP-A No. 11-217389 may be used.

  The monomer B component (including the precursor) for forming the B moiety is radically polymerizable difunctional [when R3 is an alkyl group in the formula of Chemical Formula 2], or trifunctional [in the formula of Chemical Formula 2]. And R3 is an alkoxy group], and Y=10 to 90 [mol %]. When the content of the component B is 10 [mol%] or more, sufficient toughness is obtained. Further, when it is 90 [mol %] or less, the problem that the film becomes hard and brittle and film abrasion is likely to occur can be prevented. In addition, it is possible to prevent deterioration of environmental characteristics. If a large number of hydrolyzed crosslinking components remain as silanol groups, environmental characteristics (humidity dependence) may be deteriorated.

  Examples of the monomer B component include 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltriethoxysilane. Further, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltri(isopropoxy)silane, 3-acryloxypropyltri(isopropoxy)silane and the like may be used.

式中で、Ｒ１、ｍ、Ｒ２、Ｒ３、Ｘ、Ｙは、それぞれ上述したものと同じ。 Obtained by hydrolyzing a copolymer represented by the following formula 3 and obtained by radically copolymerizing a monomer A component and a monomer B component to generate a silanol group and condensing with a catalyst. It is preferable to coat the core material with the crosslinked product to be heat-treated to form a resin layer.

In the formula, R1, m, R2, R3, X and Y are the same as those described above.

式中において、Ｒ１、ｍ、Ｒ２、Ｒ３、Ｘ、Ｙは、それぞれ上述したものと同じ。 An acrylic compound (monomer) may be added as the C component to the A component and the B component. A copolymer represented by the following chemical formula 4 can be given as an example in which such a monomer C component (also referred to as C component) is added.

In the formula, R1, m, R2, R3, X and Y are the same as those described above.

  In the copolymer of the above formula, X=10 [mol%] to 40 [mol%], Y=10 [mol%] to 40 [mol%], and Z=30 [mol%] to 80 [mol%]. Mol%] and “60 [mol%]<Y+Z<90 [mol%]”.

式中で、Ｒ１、Ｒ２は上述したものと同じである。 The C component is represented by the following chemical formula 5.

In the formula, R1 and R2 are the same as those described above.

  The C component imparts flexibility to the coating layer and improves the adhesiveness between the core material and the coating layer, but if the C component is 30 [mol%] or more, sufficient adhesion is achieved. Sex is obtained. Further, when it is 80 [mol%] or less, it is possible to prevent either of the A component and the B component from becoming 10 [mol%] or less, and the water repellency, hardness and flexibility of the carrier film (film scraping). Can be achieved at the same time.

  The acrylic compound (monomer) as the C component is preferably an acrylic acid ester or a methacrylic acid ester. Specific examples thereof include methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, butyl acrylate, and 2-(dimethylamino)ethyl methacrylate. Further, 2-(dimethylamino)ethyl acrylate, 3-(dimethylamino)propyl methacrylate, 3-(dimethylamino)propyl acrylate, etc. may be used. Of these, alkyl methacrylate is more preferable, and methyl methacrylate is particularly preferable. Further, one kind of these compounds may be used alone, or a mixture of two or more kinds may be used.

As a technique for enhancing durability by crosslinking the resin coat layer C _a2 , the technique described in Japanese Patent No. 3691115 can be used. A copolymer of an organopolysiloxane having a vinyl group at least at the terminal and a radical copolymerizable monomer having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, an amide group and an imide group is prepared. It is a technique of coating the surface of magnetic particles with a thermosetting resin crosslinked with an isocyanate compound. However, with this technique, there is a possibility that sufficient durability may not be obtained against peeling or excessive abrasion of the resin coat layer C _a2 . The reason is not clear, but in the case of a thermosetting resin obtained by crosslinking the above-mentioned copolymer with an isocyanate compound, it is considered as follows. That is, the functional group (active hydrogen-containing group such as amino group, hydroxy group, carboxy group and mercapto group) per unit weight that reacts (crosslinks) with the isocyanate compound in the copolymer resin is small, and two-dimensional , Or a three-dimensional dense crosslinked structure cannot be formed. For this reason, when used for a long time, peeling of the coating or excessive abrasion is likely to occur (the abrasion resistance of the coating layer is small), and it is presumed that sufficient durability cannot be obtained.

When the resin coat layer C _a2 is peeled off or excessively scraped, a change in image quality due to a decrease in carrier resistance and carrier adhesion occur. In addition, the fluidity of the developer is reduced, which causes a decrease in the amount of the developer drawn up by the sleeve, which causes a decrease in image density, scumming due to excessive toner density, and toner scattering.

Therefore, in the carrier used in the copying machine according to the embodiment, the resin coating layer C _a2 has a large number of bifunctional or trifunctional crosslinkable functional groups (points) per unit weight of resin (2 per unit weight). 2 to 3 times as many). Further, since the resin is formed by cross-linking the resin by polycondensation, the resin coat layer C _a2 is made extremely tough to prevent the resin coat layer C _a2 from peeling or excessive scraping. .. In addition, since the resin has a larger bond energy due to the cross-linking by the siloxane bond than the cross-linking by the isocyanate compound and is stable against heat stress, it is possible to improve the temporal stability of the resin coat layer C _a2. Is possible.

It is preferable that the copolymer is hydrolyzed to generate a silanol group and polycondensed to form the resin coat layer Ca ₂ . Examples of the catalyst used in the condensation polymerization include titanium-based catalysts, tin-based catalysts, zirconium-based catalysts and aluminum-based catalysts. Among these catalysts, a titanium-based catalyst is preferably used, and titanium diisopropoxybis(ethylacetoacetate) is particularly preferably used. It is considered that this has a large effect of promoting the condensation reaction of the silanol group and that the catalyst is hard to deactivate.

As the resin forming the resin coat layer C _a2 , in addition to the above-mentioned resins, silicon resin, acrylic resin, or these can be used together. Acrylic resin has excellent adhesiveness and low brittleness, so it has very good abrasion resistance, but on the other hand, it has high surface energy, so when used in combination with a toner that easily spends, toner component spent accumulates. There may be a problem such as a decrease in charge amount due to. In this case, since the surface energy is low, it becomes difficult to generate spent of the toner component. The above-mentioned problems can be prevented by using together with the silicone resin, which is effective in abrading the resin coat layer C _a2 and making it difficult to form the spent layer of the toner on the carrier surface. On the other hand, since the silicone resin has weak adhesiveness and high brittleness, it is inferior in abrasion resistance. Therefore, when two or more kinds of resins are used in combination, it is preferable to consider the balance of each resin so that the resin coating layer C _a2 that is hard to be spent and has abrasion resistance can be formed.

  As the silicone resin, generally known silicone resins can be used. For example, straight silicone composed only of organosilosan bond, silicone resin modified with alkyd, polyester, epoxy, acrylic, urethane and the like can be mentioned. Examples of commercially available straight silicone resins include KR271, KR255, KR152 manufactured by Shin-Etsu Chemical, SR2400, SR2406, SR2410 manufactured by Toray Dow Corning Silicone. It is possible to use these as a silicon resin alone, but it is also possible to simultaneously use other components that undergo a crosslinking reaction, charge amount adjusting components, and the like. Furthermore, examples of the modified silicone resin include KR206 (alkyd modified), KR5208 (acrylic modified), ES1001N (epoxy modified), and KR305 (urethane modified) manufactured by Shin-Etsu Chemical. Further, SR2115 (epoxy-modified), SR2110 (alkyd-modified) manufactured by Toray Dow Corning Silicon Co. may be used.

As a method of forming the resin coat layer C _a2 , for example, the following method can be used. That is, the barium sulfate fine particles, a silicone resin having a silanol group and/or a hydrolyzable functional group, and a catalyst are added to the copolymer. If necessary, a coating layer composition containing a resin other than a silicone resin having a silanol group and/or a hydrolyzable functional group, a solvent, etc. is added. The resin coat layer C _a2 is formed using the obtained resin. Specifically, it may be formed by condensing silanol groups while coating the core material C _a1 with the resin, or by coating the core material C _a1 with the resin and then condensing the silanol groups. It may be formed. The method of condensing the silanol groups while coating the core material C _a1 with the resin is not particularly limited, and examples thereof include a method of coating the core material C _a1 with the resin while applying heat, light or the like. The method of condensing the silanol groups after coating the core material C _a1 with the resin is not particularly limited, but includes a method of coating the core material C _a1 with the resin and then heating.

It is preferable that the resin coat layer C _a2 has no film defects and that the average film thickness thereof is 0.30 to 1.50 [μm]. When the average film thickness is 0.30 [μm] or more, the chargeable fine particles C _a3 can be sufficiently held, so that the chargeable fine particles C _a3 can be prevented from separating from the resin coating layer C _a2 . Further, when the average film thickness is 1.50 [μm] or less, it is possible to prevent the problem that it is difficult to take in the chargeable fine particles C _a3 into the resin coat layer C _a2 and exert sufficient chargeability. be able to.

The core material C _a1 is not particularly limited as long as it is a magnetic material, but is not limited to ferromagnetic metals such as iron and cobalt; iron oxides such as magnetite, hematite, and ferrite; various alloys and compounds; Examples include dispersed resin particles. Among them, Mn-based ferrite, Mn-Mg-based ferrite, and Mn-Mg-Sr ferrite are preferable from the viewpoint of environment.

  In the developer containing the toner and the carrier, the toner may be monochrome toner or color toner.

FIG. 9 is a diagram schematically showing the surface of a carrier set in the developing device 5 of the copying machine according to the embodiment and used for a certain period of time. Due to stress in the developing device 5, the resin coat layer C _a2 is scraped off, and the ratio of the chargeable fine particles C _a3 exposed on the surface of the coat layer is increased compared to the initial stage. On the other hand, in the resin coat layer C _a2 , the spent layer Sp of the toner is fixed at the same time as the abrasion. As a result, the toner charging performance of the resin coat layer C _a2 portion is deteriorated, but instead, the exposure amount of the charging fine particles C _a3 increases, so that the entire carrier exhibits sufficient toner charging performance.

FIG. 10 is a diagram schematically showing a carrier surface which is set in the low stress developing device 5′ and used for a certain period of time. Since the stress applied to the carrier by the low-stress developing device 5′ is weak, the resin coat layer C _a2 is not scraped and the chargeable fine particles C _a3 are not exposed on the surface. On the other hand, since the fixing of the spent layer Sp of the toner to the resin coating layer C _a2 progresses, most of the carrier surface covered with spent layer Sp, it becomes impossible to exhibit sufficient toner charge performance as a whole carrier .. As a result, various problems due to insufficient toner charge amount such as toner scattering, transfer failure, and background stain (fogging) occur.

  Therefore, the developing device 5 of the copying machine according to the embodiment is configured to apply a relatively strong stress to the carrier such that the resin coating layer Ca2 of the carrier is surely scraped away with time.

Next, a characteristic configuration of the copying machine according to the embodiment will be described.
In order to apply the relatively strong stress to the carrier as described above, the presence of the chargeable fine particles C _{a3 on} the surface of the carrier due to the abrasion of the resin coating layer C _a2 at least during the period when printing for 40,000 pages is completed from the initial stage. The ratio needs to be increased. It is known from the results of various experiments conducted by the present inventors that the number of sheets of 40,000 sheets is saturated with the toner charge performance of the carrier due to the spent of toner at about 40,000 sheets or less. ..

FIG. 11 shows a change over time in the toner charge amount (Q/M) when a test image is continuously printed using a toner B having a low temperature fixing property described later using MPC8002 manufactured by Ricoh Co., Ltd. as a printer tester. It is a graph. As the continuous printing condition, a condition is adopted in which toner images of respective colors having an image area ratio of 40% are continuously printed on A4 paper at 1000 [page/Job]. Unlike the copying machine according to the embodiment, a carrier containing no chargeable fine particles C _a3 in the resin coat layer C _a2 is set in the developing device 5 for each color (carrier set as standard in MPC8002). I'm using one. Therefore, even if the resin coating layer C _a2 wears over time, the toner charging performance of the carrier does not increase accordingly. As shown in the figure, in the period until 20,000 sheets are continuously printed, the toner charge amount sharply decreases as the number of printed sheets increases. However, when the number of prints exceeds 20,000, the toner charge amount does not decrease so much even if the number of prints increases. When the number of prints reaches 40,000 (the position of the dot in the figure), the toner charge amount is maintained constant even after the number of prints increases.

FIG. 12 shows a change over time in the toner charge amount (Q/M) when a test image is continuously printed using a toner B having a low-temperature fixing property described later using MPC4502 manufactured by Ricoh Co., Ltd. as a printer tester. It is a graph. As the continuous printing condition, a condition is adopted in which toner images of respective colors having an image area ratio of 20% are continuously printed on A4 paper at 1000 [page/Job]. Unlike the copying machine according to the embodiment, the developing device 5 for each color has a carrier in which the resin-coated layer C _a2 does not contain the chargeable fine particles C _a3 (a carrier set as standard in the MPC4502). ) Is used. Therefore, even if the resin coating layer C _a2 wears over time, the toner charging performance of the carrier does not increase accordingly. As shown in the figure, in the period until 40000 sheets are continuously printed (the position indicated by the dotted line in the figure), the toner charge amount sharply decreases as the number of printed sheets increases. However, when the number of prints exceeds 40,000, the toner charge amount does not decrease so much even if the number of prints increases. When the number of prints reaches 40,000 (the position of the dot in the figure), the toner charge amount does not decrease thereafter even if the number of prints increases.

FIG. 13 shows a change over time in the toner charge amount (Q/M) when a test image is continuously printed using a low-temperature fixing toner B described below using MPC4503 manufactured by Ricoh Co., Ltd. as a printer tester. It is a graph. As the continuous printing condition, a condition is adopted in which toner images of respective colors having an image area ratio of 20% are continuously printed on A4 paper at 1000 [page/Job]. Different from the copying machine according to the embodiment, the developing device 5 for each color has a carrier in which the resin coating layer C _a2 does not contain the chargeable fine particles C _a3 (a carrier set as standard in the MPC4503). ) Is used. Therefore, even if the resin coating layer C _a2 wears over time, the toner charging performance of the carrier does not increase accordingly. As shown in the figure, in the period until 40000 sheets are continuously printed (the position indicated by the dotted line in the figure), the toner charge amount sharply decreases as the number of printed sheets increases. However, when the number of prints exceeds 40,000, the toner charge amount does not decrease so much even if the number of prints increases. When the number of prints reaches 40,000 (the position of the dot in the figure), the toner charge amount does not decrease thereafter even if the number of prints increases.

From these experimental results, when a carrier containing no chargeable fine particles C _a3 and a low temperature fixing toner are used in combination, the toner charging performance of the carrier is deteriorated due to the toner spent. It can be seen that the following prints saturate and stabilize.

As a method of adjusting the strength of the stress applied to the carrier in the developing device 5, a method of adjusting the magnetic flux density of the fifth magnetic pole P5 or an amount of the developer existing in the magnetic field influence range of the fifth magnetic pole P5 is adjusted. There is a method of doing. By using these methods, the carrier by the developing device 5 is configured to increase the abundance ratio of the charging fine particles C _a3 measured by XPS by the time the printing of at least 40,000 sheets is completed. The amount of stress applied to the is adjusted. In other words, the surface exposure amount of the chargeable fine particles C _a3 is increased at the time of printing 40000 sheets as compared with the initial amount. In particular, it is desirable that the existence ratio is increased by 0.2 [atomic %] or more by comparing the initial time and the time of printing 40,000 sheets.

If it can be confirmed that the abundance ratio of the charging fine particles C _{a3 on} the surface of the carrier measured using XPS is 40,000 or less and 40,000 sheets or more are increased compared to the initial carrier, 40,000 prints are not necessarily printed. No need to go and check.

  As an image output mode for measuring the existence ratio, it is desirable to output an image having a large image area because the toner spent in the developing device 5 is replaced, that is, as the toner consumption amount is large, the toner spent tends to proceed. .. According to the statistics of output mode of users, most users use the image area ratio of 40% or less for high speed machines of 51 [cpm] or more and the image area ratio of 20% or less for low speed machines of 50 [cpmtn flat or less. I found out. For this reason, an image having an image area ratio of 40% is output for a high-speed machine of 51 [cpm] or more, and an image having an image area ratio of 20% is output for a low-speed machine of 50 [cpm] or less.

The abundance ratio of the chargeable fine particles C _a3 (comprising an element having an electronegativity of 1.4 or less) on the carrier surface can be measured as follows. That is, the carrier is recovered from the inside of the developing device 5, and the toner adhering to the surface of the carrier is air blown using a 795 mesh. The obtained air-blown carrier is put into X-ray electron spectroscopy (XPS), and the abundance ratio of the element on the surface is determined under the following conditions.
・Measuring device: Thermo Scientific K-Alpha
・Measuring light source: Al (monochrometer)
・Measuring area spot diameter: 400 [μm]
・Pass energy: 50 [eV]
・Energy step: 0.1 [eV]

Next, the experiments conducted by the present inventors will be described.
We have manufactured carriers. Specifically, 300 [g] of toluene was put into a flask equipped with a stirrer and heated to 90 [°C] under a nitrogen gas stream. To this was added a mixture consisting of a mixture of the substances listed below dropwise over 1 hour.
_{· CH 2 = CMe-COO-} C 3 H 6 -Si (OSiMe 3) 3 [ wherein, Me represents a methyl group] 3-methacryloxypropyl tris (trimethylsiloxy) silane 84.4 g (200 mmol represented by: Sila plane, TM-0701T/Chisso Corporation)
-39 g (150 mmol) of 3-methacryloxypropylmethyldiethoxysilane
・Methyl methacrylate 65.0 g (650 mmol)
-0.52 g (3 mmol) of 2,2'-azobis-2-methylbutyronitrile

  After the dropwise addition was completed, the following solution was further added, and the mixture was mixed at 90 to 100[° C.] for 3 hours for radical copolymerization to obtain a methacrylic copolymer 1. That is, 0.06 [g] (0.3 mmol) of 2,2′-azobis-2-methylbutyronitrile was dissolved in 15 [g] of toluene (2,2′-azobis-2-). The total amount of methylbutyronitrile was 0.64 [g] (3.3 mmol)).

The following substances were mixed with 20 parts by weight of the obtained methacrylic copolymer having a weight average molecular weight of 35,000 [solid content 100% by mass].
-Silicon resin solution (SR2410 manufactured by Toray Dow Corning Silicone Co., Ltd.) [solid content 20 mass%] 100 parts by weight-Aminosilane [solid content 100 mass%] 3.0 parts by weight-Charging fine particles _Ca3 (barium sulfate particles Sakai) 36 parts by weight of chemical B55) 60 parts by weight of conductive fine particles (oxygen-deficient tin Mitsui Kinzoku primary particle diameter 30 nm) 2 parts of catalyst (titanium diisopropoxybis(ethylacetoacetate) TC750 Matsumoto Fine Chemical Co., Ltd.) Parts by weight

The mixture was diluted with toluene to obtain a resin solution having a solid content of 20% by mass. As the core material C _a1 , Mn ferrite particles having a weight average particle diameter of 35 [μm] were used, and the resin solution was applied to the surface of the core material C _a1 using a atomizing nozzle in a fluidized bed type coating device. The resin solution is applied so that the average film thickness of the resin coat layer C _a2 becomes 1.00 [μm], and the coating or the applied film is controlled while controlling the temperature in the fluidized tank to 60 [° C.]. It was dried. The obtained carrier was baked in an electric furnace at 210° C. for 1 hour. After cooling, the obtained dried product was crushed using a sieve with an opening of 63 [μm] to obtain a carrier with a particle size of 35 [μm]. Hereinafter, this carrier is referred to as carrier A.

  As the developing device, the developing device 5 according to the embodiment shown in FIG. 2 and the low stress developing device 5'shown in FIG. 5 were used. A developer having a toner concentration of 7% was prepared by mixing the obtained carrier A and the toner, and 240 g of the developer was put into each developing device (all used for M). As the toner, a Magenta toner for MPC2503 manufactured by Ricoh Co., Ltd. was used. MPC2503 manufactured by Ricoh Co., Ltd. is used as a printer tester, and a job of continuously printing 100 M test images with an image area of 20% is repeated every 300 seconds, and a cumulative print of 40,000 sheets. Was carried out. Each time each job was completed, an appropriate amount of M toner was sampled from the developing device, and the charge amount was measured. The laboratory environment has a temperature of 23 [° C.] and a relative humidity of 50 [%].

FIG. 14 is a graph showing the change over time in the toner charge amount in this first experiment. The initial toner charge amount is not significantly different between the embodiment (developing device 5) and the low stress development (low stress developing device 5′). However, at the time of printing 40,000 sheets, in the embodiment, the toner charge amount is not much different from the initial charge amount, whereas in the low stress development, the toner charge amount is considerably lower than the initial value. This is because in the low stress development, the resin coat layer C _a2 of the carrier is not worn and the spent layer Sp of the toner grows on the surface of the carrier with time.

FIG. 15 is a graph showing the results of measuring the abundance ratio of the chargeable fine particles C _a1 (barium sulfate in the first experiment) on the carrier surface by XPS. As shown in the figure, in the embodiment, the developing device 5 applies relatively strong stress to the carrier to wear the resin coating layer C _a2 of the carrier over time. The abundance ratio Ba of _a3 is increased by 0.25 [atomic %] compared to the initial stage. On the other hand, in the low stress development, the abrasion of the resin coat layer C _a2 does not proceed so much, and the spent layer Sp of the toner is formed on the carrier surface. Therefore, the abundance ratio of the chargeable fine particles C _a3 at the time of printing 40,000 sheets. Ba is decreased by 0.08 [atomic %] from the initial value.

As described above, in the carrier in which the chargeable fine particles C _a3 are dispersed in the resin coating layer C _a2 , the presence of the chargeable fine particles C _a3 at the time of printing 40,000 sheets can be achieved by combining the carrier with the developing device 5 that applies relatively strong stress. The ratio Ba can be increased from the initial value. This makes it possible to maintain good toner charging performance of the carrier over a long period of time.

Next, the second experiment conducted by the present inventors will be described.
As a comparative carrier, a carrier (BR1603 carrier) for ProC901 manufactured by Ricoh Co., Ltd. was prepared. Unlike the carrier (for example, carrier A) used in the copying machine according to the embodiment, this comparative carrier does not contain the chargeable fine particles C _a3 in the resin coat layer C _a2 . Therefore, the toner charging performance is reduced as the resin coat layer C _a2 wears.

When the abundance ratio of barium sulfate (chargeable fine particles C _a3 of the carrier A) on the carrier surface was measured by XPS, it was 0.15 [atomic%] for the carrier A (initial), but 0 for the comparative carrier. It was [atomic %].

  Various toners were made. First, ketimine was synthesized. Specifically, 170 parts by weight of isophoronediamine 170 and 75 parts by weight of 75 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stir bar and a thermometer and reacted at 50 [° C.] for 5 hours to give [ketimine. Compound] was obtained. The amine value of this [ketimine compound] was 418.

  Next, prepolymer A was synthesized. Specifically, 3-methyl-1,5-pentanediol, terephthalic acid, adipic acid, and titanium tetraisopropoxide (resin component was added to a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe. 1,000 ppm) was added. At this time, OH/COOH, which is the molar ratio of the hydroxyl group to the carboxyl group, was set to 1.15, 3-methyl-1,5-pentanediol in the diol component was set to 100 [mol %], and terephthalic acid in the dicarboxylic acid component was set to 100%. It was set to 40 [mol %]. Furthermore, the amount of adipic acid in the dicarboxylic acid component was set to 60 [mol]. After that, the temperature was gradually raised to 200 [° C.] in about 4 hours, and further raised to 230 [° C.] over 2 hours, and the reaction was performed until the outflow water disappeared. Then, it was made to react under reduced pressure of 10 [mmHg]-15 [mmHg] for 6 hours, and intermediate polyester A'was obtained. The glass transition temperature Tg of the obtained intermediate polyester A′ was −50 [° C.], Mw was 18,000, and Mw/Mn was 2.0.

  In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, an intermediate polyester A'and an isocyanurate type triisocyanate derived from hexamethylene diisocyanate (Bernock DN-901S manufactured by DIC Corporation) are charged. did. At this time, the molar ratio (isocyanate group of DN-901S/hydroxyl group of intermediate polyester) was adjusted to 0.1. The mixture was diluted with ethyl acetate to give a 50% ethyl acetate solution, and then reacted at 100[° C.] for 5 hours to obtain an intermediate polyester A solution. The glass transition temperature Tg of the obtained intermediate polyester A was −45 [° C.], Mw was 22,000, and Mw/Mn was 2.2.

  In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, the intermediate polyester A-10 solution and isophorone diisocyanate (IPDI) were brought to a molar ratio of 1.5 (isocyanate group of IPDI/hydroxyl group of intermediate polyester). I put it in to do. Then, it was diluted with ethyl acetate so as to be a 50% ethyl acetate solution, and then reacted at 100 [° C.] for 5 hours to obtain a prepolymer A solution.

  Next, polyester resin A was synthesized. Specifically, the above-mentioned prepolymer A was stirred in a reaction vessel equipped with a heating device, a stirrer and a nitrogen introducing tube. Furthermore, the [ketimine compound] was added dropwise to the reaction vessel in an amount such that the amine amount of the [ketimine compound] was equimolar to the amount of isocyanate in the prepolymer A, and the mixture was stirred at 45 [° C.] for 10 hours before pre-treatment. The polymer extension product was taken out. The obtained prepolymer extension product was dried under reduced pressure at 50[° C.] so that the amount of residual ethyl acetate was 100 [ppm] or less, to obtain an amorphous polyester resin A.

  Next, polyester resin B was synthesized. Specifically, in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, 2 mol of bisphenol A ethylene oxide side adduct, 3 mol of bisphenol A propylene oxide adduct, isophthalic acid, and Adipic acid was added. At this time, the molar ratio of the bisphenol A ethylene oxide side 2 mol adduct and the bisphenol A propylene oxide 3 mol adduct was adjusted to 85/15. The molar ratio is 2 mol of bisphenol A ethylene oxide side adduct/3 mol of bisphenol A propylene oxide. Further, the molar ratio of terephthalic acid and adipic acid (terephthalic acid/adipic acid) was adjusted to 80/20. Further, the molar ratio of the hydroxyl group to the carboxyl group (OH/COOH) was adjusted to 1.2. Next, it is allowed to react with titanium tetraisopropoxide (500 ppm with respect to the resin component) at normal pressure and 230 [° C.] for 8 hours, and then at a reduced pressure of 10 [mmHg] to 15 [mmHg] for 4 hours. It was Then, trimellitic anhydride was added to the reaction vessel so as to be 1 [mol%] with respect to all resin components, and then reacted at 180 [° C.] and normal pressure for 3 hours to obtain amorphous polyester resin B. Obtained.

  Next, crystalline polyester resin C was synthesized. Specifically, dodecanedioic acid, 1,6-hexanediol, and titanium tetraisopropoxide (as a resin component) were placed in a 5 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. 500 ppm) was charged. At this time, the molar ratio of the hydroxyl group and the carboxyl group (OH/COOH9 was adjusted to 0.9. Then, after reacting at 180 [°C] for 10 hours, the temperature was raised to 200 [°C] and reacted for 3 hours. Then, the reaction was continued for 2 hours at a pressure of 8.3 [kPa] to obtain a crystalline polyester resin C.

  Next, a master batch (MB) was produced. Specifically, first, in 1,200 parts by weight of water, 500 parts by weight of carbon black (manufactured by Printex 35 Dexa) [DBP oil absorption=42 mL/100 mg, pH=9.5], and 500 parts by weight of polyester resin B was added. Then, they were mixed by a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was kneaded by two rolls under the condition of 150[° C.] for 30 minutes and then rolled and cooled. Then, the kneaded product was pulverized with a pulverizer to obtain a [masterbatch].

  Next, a WAX dispersion liquid was prepared. Specifically, first, 50 parts by weight of paraffin wax, 50 parts by weight (manufactured by Nippon Seiro Co., Ltd., HNP-9, hydrocarbon wax, melting point, as a release agent, is placed in a container in which a stirring rod and a thermometer are set. At 75° C., SP value of 8.8), and 450 parts by weight of ethyl acetate (450 parts) were charged. Then, the temperature was raised to 80[° C.] with stirring, the temperature was kept at 80[° C.] for 5 hours, and then cooled to 30° C. for 1 hour. Then, dispersion treatment was performed using a bead mill (Ultra Visco Mill, manufactured by AIMEX Co., Ltd.) to obtain [WAX dispersion liquid]. At this time, as the dispersion conditions, a liquid feed rate of 1 [kg/hr], a disk peripheral velocity of 6 [m/sec], a volume of 0.5 [mm] zirconia beads filled at 80% by volume, and 3 passes were adopted. ..

  Next, a crystalline polyester resin dispersion was prepared. Specifically, in a container with a stir bar and thermometer. 50 parts by weight of the crystalline polyester resin C and 450 parts by weight of 450 parts of ethyl acetate were charged. Then, the temperature was raised to 80[° C.] while stirring, held at 80[° C.] for 5 hours, and then cooled to 30[° C.] in 1 hour. Then, a dispersion treatment was performed using a bead mill (Ultra Visco Mill, manufactured by AIMEX Co., Ltd.) to obtain [Crystalline polyester resin dispersion liquid]. At this time, as the dispersion conditions, a liquid feed rate of 1 [kg/hr], a disk peripheral velocity of 6 [m/sec], a volume of 0.5 [mm] zirconia beads filled at 80% by volume, and 3 passes were adopted. ..

Next, an oil phase was prepared. Specifically, the following substances were put in a container.
-[WAX dispersion] 500 parts by weight-[Prepolymer A] 200 parts by weight-[Crystalline polyester resin dispersion] 500 parts by weight-[Polyester resin B] 750 parts by weight-[Masterbatch] 100 parts by weight-Curing agent 2 parts by weight of kettle [ketimine compound]

  Then, they were mixed for 60 minutes at a speed of 5,000 [rpm] with a TK homomixer (made by Tokushu Kiki Co., Ltd.) to obtain [oil phase].

Next, an organic fine particle emulsion (fine particle dispersion liquid) was synthesized. Specifically, the following substances were charged in a reaction vessel equipped with a stir bar and a thermometer.
・683 parts by weight of water ・11 parts by weight of sodium salt of sulfuric acid ester of methacrylic acid ethylene oxide adduct (Eleminol RS-30: manufactured by Sanyo Chemical Industry Co., Ltd.) ・138 parts by weight of styrene ・138 parts by weight of methacrylic acid ・1 part by weight of ammonium persulfate

  When these were stirred at a speed of 400 [revolution/min] for 15 minutes, a white emulsion was obtained. By heating, the temperature in the system was raised to 75[° C.], and the reaction was carried out for 5 hours. Further, 30 parts by weight of a 1% ammonium persulfate aqueous solution was added, and then the mixture was aged at 75[° C.] for 5 hours. As a result, a [fine particle dispersion] was obtained, which was an aqueous dispersion of a vinyl resin (styrene-methacrylic acid-ethylene methacrylic acid ethylene oxide adduct sulfate sodium salt copolymer). The volume average particle diameter of the fine particles in this [fine particle dispersion] was measured by LA-920 (manufactured by HORIBA), and it was 0.14 [μm]. A part of the [fine particle dispersion] was dried to isolate the resin component.

Next, an aqueous phase was prepared. Specifically, the following substances were mixed.
-990 parts by weight of water-[fine particle dispersion] 83 parts by weight-37 parts by weight of 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries, Ltd.)-90 parts by weight of ethyl acetate.
These were stirred to obtain a [water phase] composed of a milky white liquid.

  Next, an emulsification/solvent removal was prepared. Specifically, 1,200 parts by weight of [aqueous phase] was added to a container containing [oil phase]. Then, the mixture was mixed for 20 minutes by a TK homomixer at a rotation speed of 13,000 [rpm] to obtain [emulsified slurry]. Next, [emulsified slurry] is put into a container in which a stirrer and a thermometer are set, and the solvent is removed at 30 [°C] for 8 hours, followed by aging at 45 [°C] for 4 hours to obtain [dispersed slurry]. Got

100 parts by weight of [dispersion slurry] was filtered under reduced pressure.
(1) Ion-exchanged water (100 parts) was added to the filter cake, mixed with a TK homomixer (rotation speed 12,000 rpm for 10 minutes), and then filtered.

  (2) After adding 100 parts by weight of a 10% sodium hydroxide aqueous solution to the filter cake of (1) and mixing with a TK homomixer (rotation speed 12,000 rpm for 30 minutes), vacuum filtration was performed.

  (3), 100 parts by weight of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed 12,000 rpm for 10 minutes), and then filtered.

  (4), 300 parts by weight of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (rotation speed 12,000 rpm for 10 minutes), and then filtered.

  The above operations (1) to (4) were repeated twice to obtain [filter cake]. This [filter cake] was dried for 48 hours at a temperature of 45[° C.] by an air-circulation dryer, and sieved with a mesh having openings of 75 [μm] to obtain [toner base particles].

  Next, external addition processing was performed. Specifically, with respect to 100 parts by weight of [toner base particles], 0.6 parts by weight of hydrophobic silica (average particle size=100 nm) and 1.0 part by weight of titanium oxide (average particle size 20 nm). And 0.8 part by weight of hydrophobic silica fine powder (average particle size 15 nm) was added. Then, these were mixed by a Henschel mixer to obtain a toner A. This toner A is a low temperature fixing toner.

  As the low-temperature fixing toner, in addition to Toner A, MPC2503 toner (SPR-F2 toner) manufactured by Ricoh Co., Ltd. was prepared. Further, as a comparative toner that is not used for low temperature fixing, a toner for ProC901 (SPR-γ toner) manufactured by Ricoh Co., Ltd. was prepared.

  Various developers were prepared. Using a ball mill, 7 parts by weight of toner (toner A, toner B, or comparative toner) and 93 parts by weight of carrier (carrier A or comparative carrier) were mixed to prepare a developer.

The low-temperature fixability of the toner was evaluated using various developers. Specifically, as a printer tester, a fixing unit remodeling machine of image MP C5002 manufactured by Ricoh Co., Ltd. was prepared. This printer tester evaluated the toner fixability when printing a test image on type 6200 paper (manufactured by Ricoh Co., Ltd.). Specifically, the cold offset temperature (fixing lower limit temperature) and the high temperature offset temperature (fixing upper limit temperature) were examined by confirming the fixability of the image while changing the fixing temperature. Regarding the evaluation conditions of the lower limit fixing temperature, the linear velocity of paper feed=200 [mm/sec], the surface pressure=1.0 [kgf/cm ² ] and the fixing nip width=7 [mm].

Table 1 below shows the characteristics of various toners.

  As shown in Table 1, toner B also exhibits better low-temperature fixability than comparative toner, while toner A exhibits even better low-temperature fixability.

  Print tests were carried out using various developers. As the developing device, the developing device 5 according to the embodiment and the low stress developing device 5'are used. 240 [g] of each of the above-described developers was set in each developing device.

MPC2503 manufactured by Ricoh Co., Ltd. was prepared as a printer tester. The job of continuously printing 100 test images with an image area of 20% was repeated every 300 seconds to print up to 40,000 sheets. Regarding toner concentration, toner replenishment control was carried out so as to maintain 7%. The initial toner charge amount and the toner charge amount at the time of printing 40,000 sheets were measured, and the rate of change between them was calculated. The results are shown in Table 2 below.

  In Table 2, the variation rate of the toner charge amount is obtained as follows. First, the toner charge amount at the time of 100-sheet print, 500-sheet print, 1000-sheet print, 2000-sheet print, and 3000-sheet print was measured by a blow-off device, and the average value thereof was used as the initial value of the toner-charge amount. did. Next, the toner charge amount at the time of printing 38,000 sheets, at the time of printing 39000 sheets, and at the time of printing 40,000 sheets was measured by a blow-off device, and the average value thereof was taken as the time-dependent value of the toner charge amount. Then, the solution of “(time-lapse value−initial value)÷initial value” was obtained as the variation rate of the toner charge amount. When the variation rate is ±20 [%] or less, it is considered that the charging is stable, and ◯ is shown in Table 2. Further, when the variation rate is 20% or more, it is considered that the charging is not stable, and x is shown in Table 2.

  The variation rate of the existence ratio Ba by XPS was obtained as follows. First, the abundance ratio Ba [atomic %] of the chargeable fine particles Ca3 on the surface of the initial carrier was measured by XPS. Next, the abundance ratio Ba [atomic %] of the chargeable fine particles Ca3 on the surface of the carrier after printing 40,000 sheets was measured by XPS. Then, the value obtained by subtracting the former existence ratio Ba from the latter existence ratio Ba was taken as the fluctuation ratio of the existence ratio. Since an error of 0.05 [atomic %] occurs in the measurement by XPS, it cannot be said that the fluctuation rate of 0.05 [atomic %] or less has a fluctuation.

In Table 2, in Experiment Nos. 1 and 2, since the toner A and the toner B having low-temperature fixability are used, sufficient low-temperature fixability is obtained. Further, by combining the carrier A in which the chargeable fine particles C _a3 are dispersed in the resin coat layer C _a2 with the developing device 5 (high stress) according to the embodiment, the variation rate of the existence ratio Ba becomes positive. ing. This indicates that the existence ratio Ba has increased from the initial value. Since the variation rate of the toner charge amount is within the range of ±20%, the toner charge performance of the carrier can be favorably maintained for a long period of time. Therefore, it is possible to achieve both excellent low-temperature fixability and long-term stability of toner charging performance of the carrier.

In Experiment No. 3, excellent low-temperature fixability was obtained by using the toner A having low-temperature fixability, but the variation rate of the toner charge amount was considerably high, and when printing 40,000 sheets, compared to the initial stage. The toner charge amount has dropped significantly. This is because the chargeable fine particles C _a3 are not present in the resin coat layer C _a2 of the carrier, so that the resin coat layer C _a2 is worn or the toner spent layer Sp is formed on the resin coat layer C _a2. This is because the toner charging performance of the carrier deteriorates with time. Therefore, both excellent low-temperature fixability and long-term stability of toner charging performance of the carrier cannot be achieved at the same time.

In Experiment No. 4, good low-temperature fixability was obtained by using the toner A having low-temperature fixability. However, since the developing device is the low stress developing device 5′, the resin coat layer C _a2 of the carrier A is not abraded over time, and the toner spent layer Sp is formed on the resin coat layer C _a2. To go. As a result, the existence ratio B at the time of printing 40,000 sheets is lower than that at the initial stage. As a result, the variation rate of the toner charge amount increases, and the toner charge amount becomes insufficient when printing 40,000 sheets. Therefore, both excellent low-temperature fixability and long-term stability of toner charging performance of the carrier cannot be achieved at the same time.

In Experiment No. 5, since the comparative toner which does not exhibit the low temperature fixing property is used, it is difficult to generate the toner spent. Therefore, the resin coating layer C _a2 of the carrier A is abraded over time to increase the existence ratio Ba, which greatly increases the variation rate of the toner charge amount. Moreover, low-temperature fixability cannot be realized. Therefore, both excellent low-temperature fixability and long-term stability of toner charging performance of the carrier cannot be achieved at the same time.

  Therefore, in Experiment No. 6, since the comparative toner is used, the low temperature fixing property cannot be realized. Since the combination of the comparative toner that is not easily softened and the low-stress developing device 5′ is used, the growth of the spent layer Sp of the toner is suppressed on the surface of the carrier A, and the toner of the carrier is maintained for a long period of time. It is possible to maintain good charging performance. However, since low-temperature fixability cannot be realized, it is not possible to achieve both excellent low-temperature fixability and long-term stability of carrier toner charging performance.

  In consideration of the above experimental results, the copying machine according to the embodiment employs the condition of Experiment No. 1 or Experiment No. 2.

Next, the copying machine according to each embodiment will be described. Unless otherwise specified below, the configuration of the copying machine according to each example is the same as that of the embodiment.
[First embodiment]
FIG. 16 is an enlarged configuration diagram showing the developing device 5 of the copying machine according to the first embodiment. In the developing device 5, the projection 70a is formed on the bottom surface which is the inner wall of the supply and recovery conveyance path 53a. These protrusions 70 a extend in the direction of the rotation axis of the stirring and conveying screw 54. Further, three projections 70b are formed on the bottom surface of the stirring/transporting path 54a. These protrusions 70b extend in the rotation axis direction of the supply and recovery screw 53.

The protrusions 70a and 70b rub against the carrier to promote the abrasion of the resin coating layer C _a2 . If the abrasion of the resin coating layer C _a2 can be promoted, the number of the protrusions 70a and the protrusions 70b, the arrangement position, and the shape are not particularly limited. Further, it is not always necessary to provide the protrusions in the supply/recovery conveyance path 53a and the stirring conveyance path 54a in good condition, and the protrusions may be provided in only one of them. When the protrusions 70a and the protrusions 70b are made of a metal material, the amount of stress applied to the carrier can be increased and wear of the resin coat layer _Ca2 can be further promoted.

  Further, when a convex portion is provided on the wall surface of the stirring and conveying path 54a, the force for stirring the agent is increased as compared with a smooth wall surface such as a normal circulation conveying path, so that the toner immediately after replenishment can be efficiently charged. The effect is obtained. That is, it becomes possible to supply the developer to the developing sleeve in a charging state that is better than in the normal configuration.

  As shown in the figure, in the configuration in which the projection 70a is provided on the bottom surface of the supply/recovery transport path 53a, the ability to stir the developer is higher than in the normal supply/recovery transport path 53a. As a result, it is possible to efficiently mix the developer whose toner concentration has been reduced by the development and the developer sent from the agitating/conveying path 54a, and reduce the toner density unevenness in the developer. Therefore, as compared with the normal configuration, it is possible to reduce toner density unevenness and realize high quality image quality.

[Second embodiment]
FIG. 17 is a partial perspective view showing the supply and recovery screw 53 in the copying machine according to the second embodiment. The supply/recovery screw 53 develops in the supply/recovery conveyance path 53a by rotating the screw blade portion 53c that is a conveyance blade portion around a screw shaft 53b that is a conveyance rotation shaft that extends in the rotation axis direction of the developing sleeve 51. The agent G is conveyed.

The supply/recovery screw 53 has an outer peripheral portion 53d of a wing portion 53c made of metal. Then, as compared with the configuration in which the outer peripheral portion is not made of metal, abrasion of the resin coat layer C _a2 of the carrier is promoted. When combined with the protrusion 70a of the copying machine according to the second embodiment, the abrasion of the resin coat layer _Ca2 can be further promoted. Further, in the stirring and conveying screw 54, the outer peripheral portion (tip portion) of the wing portion may be made of metal, similarly to the supply and recovery screw 53.

[Third embodiment]
FIG. 18 is a configuration diagram showing the developing device 5 according to the third embodiment. A second layer thickness regulating member 82 is provided on the upstream side of the developing region in the surface moving direction of the developing sleeve 51, in addition to the doctor blade 52 which is the first layer thickness regulating member. The second layer thickness regulating member 82 has a predetermined gap in the circumferential direction of the developing sleeve 51 after passing through the developing area and before entering a position facing the supply/recovery conveying path 53a. (Hereinafter, referred to as a second regulation gap). The second regulation gap is narrower than the doctor gap formed by the doctor blade 52.

Since the developer passing through the second regulation gap has the toner concentration lowered with the development immediately before, the resin coating layer C is caused by the friction with the second layer thickness regulating member 82 or the friction between the carriers. Efficiently wear _a2 . During development of an image having a large image area where toner spent is likely to proceed, the toner concentration of the developer is considerably lowered. In this case, an image having a large image area in which the spent is easily advanced is output, but the toner concentration is considerably lowered, and the effect of _abrading the resin coat layer C _a2 is further enhanced. Therefore, even when an image having a large image area is output, the spent of toner can be favorably suppressed.

  Although the second layer thickness regulating member 82 is provided in substantially the same direction as the direction in which the magnetic flux density in the normal direction on the surface of the developing sleeve of the third magnetic pole P3 is maximized, the installation position is not limited to this. Further, when it is necessary to further strengthen the stress on the developer, the number of the gap forming members installed may be increased.

What has been described above is an example, and the following unique effects can be obtained.
[Aspect A]
A circulation transfer path (for example, a combination of the supply/recovery transfer path 53a and the stirring transfer path 54a) for circulating and transferring the developer containing the toner and the carrier, and a transfer body (for example, a combination of the transfer transfer path 53a and the stirring transfer path 54a) that transfers the developer. The supply/recovery screw 53 and the agitating/conveying screw 54) and the developer supplied from the circulation/conveying path are carried on their own surfaces, and then conveyed to a position facing the latent image carrier along with their own surface movement. A developing device (for example, developing device 5) having a developer carrying member (for example, developing sleeve 51) for developing the latent image on the latent image carrying member, wherein the carrier has an electronegativity of 1.4 or less. Using a resin coating layer (for example, resin coating layer C _a2 ) in which fine particles of a certain substance are dispersed is coated on the surface of a particle core material (for example, core material C _a1 ), an image of 40,000 pages from the beginning is used. It is characterized in that the carrier is given a stress for increasing the abundance ratio (for example, abundance ratio Ba) of the fine particles on the surface of the carrier from the initial stage within the period until development.

  In such a configuration, the fine particles dispersed in the resin coat layer are generally exposed in the surface of the resin coat layer and rubbed with a general resin toner to generally adopt the toner in the reversal development method. It is charged to the negative polarity which is the polarity. The fine particles dispersed in the resin coat layer have higher hardness than resin. Then, among the dispersed fine particles, a strong frictional force acts between the fine particles exposed from the surface of the resin coating layer and the carrier (for example, the supply/recovery screw) or another carrier. Spent of toner is unlikely to occur on the surface of the fine particles. Since the solid surface of the resin coat layer has a relatively low hardness and elasticity, the spent toner may adhere to form a spent layer. When this spent layer grows to the extent that it protrudes beyond the fine particles exposed from the surface of the resin coat layer, a step is created between the surface of the fine particles and the spent layer, so that the side of the protrusion of the spent layer is Friction force comes to be applied from one side. Due to this frictional force from the side, the spent layer is peeled off from the solid surface of the resin coat layer. Further, a frictional force is exerted from the side on the protruding portion of the fine particles that partially project themselves from the surface of the resin coating layer, or a carrier is applied to the solid surface of the resin coating layer. Will be rubbed directly. As a result, the fine particles protruding from the surface of the resin coat layer and the solid surface of the resin coat layer are scraped off, and the resin coat layer is gradually worn away. Then, along with the abrasion, fine particles that were not exposed to the surface of the resin coat layer until then become newly exposed, or the cross-sectional area after abrasion of the already exposed fine particles increases. The ratio of the fine particles present on the carrier surface is higher than in the initial stage. In the mode A, the stress in the developing device is applied to the carrier in the developing device in such a manner that the abundance ratio of the fine particles on the carrier surface is increased within the period from the initial stage until the image of 40,000 pages is developed. In such a configuration, as in the experimental results shown in the embodiment, even if the thickness of the resin coat layer is reduced due to wear, friction between the fine particles dispersed in the resin coat layer and the toner keeps the toner for a long period of time. It can be stably charged over a long period of time. Therefore, in the developing device, the toner in which the surface of the particle core material is coated with the resin coating layer can reliably charge the toner satisfactorily for a long period of time.

[Aspect B]
Aspect B is characterized in that, in Aspect A, a carrier having a volume average particle diameter of 300 [nm] or more and 900 [nm] or less is used as the carrier. With this configuration, it is possible to prevent the toner charging performance of the carrier from being insufficient due to the insufficient protrusion height of the fine particles from the surface of the resin coating layer. Further, it is possible to suppress the formation of the spent layer of the toner on the entire carrier due to the insufficient height of the fine particles protruding. Further, it is possible to prevent the fine particles from being separated from the resin coating layer due to the volume average particle diameter of the fine particles being too large.

[Aspect C]
Aspect C is a method according to Aspect B or A, wherein the resin coat layer is made of a resin material containing an aminosilane coupling agent, as the carrier. With such a configuration, the toner charging performance of the carrier in the initial state can be adjusted by the amount of the aminosilane coupling agent.

[Aspect D]
Aspect D is characterized in that in any of Aspects A to C, the toner having a storage elastic modulus at 80 [° C.] of 1.9×10 ⁵ [Pa] or less is used. With such a configuration, it is possible to prevent the toner charging performance of the carrier from deteriorating with time while realizing excellent low-temperature fixability of the toner.

[Aspect E]
Aspect E is a toner according to Aspect D, wherein the toner has a storage elastic modulus at 50 [° C.] of 1.0×10 ⁷ [Pa] or more and a storage elastic modulus at 160 [° C.] of 2.1×10 ^3. It is characterized by using a material having a pressure of [Pa] or less. In such a configuration, the storage elastic modulus at 50[° C.] of the toner is 1.0×10 ⁷ [Pa] or more, so that the toner can exhibit good heat resistant storage stability. In addition, the storage elastic modulus at 160 [° C.] of the toner is 2.1×10 ³ [Pa] or less, so that the toner has good offset resistance (transfer of the toner to a fixing roller or the like). Prevent) can be exerted.

[Aspect F]
Aspect F is characterized in that, in Aspect D or E, the toner particles are made of a material containing an amorphous polymer resin and a crystalline polymer resin. In such a configuration, by including the crystalline polymer in the toner, it is possible to exhibit good low-temperature fixability for the toner. Further, even if the toner spent layer is attached to the carrier due to the inclusion of the crystalline polymer in the toner, the action of the amorphous polymer resin causes the toner of the carrier due to the spent attachment. It is possible to suppress a decrease in charging performance.

[Aspect G]
Aspect G is the toner according to Aspect F, wherein the difference between the glass transition temperature at the first temperature increase and the glass transition temperature at the second temperature increase in the differential scanning calorimetry of the toner particles is 10 [° C.] or more. It is characterized by being used. With such a constitution, it is possible to exhibit good low-temperature fixing property, sharp melt property, and heat-resistant storage property for the toner.

[Aspect H]
Aspect H is the same as Aspect G, except that the toner particles are made of a material containing an amorphous polyester resin, the amorphous polyester resin has a branched structure, and the amorphous polyester resin has a branched structure. The resin having a glass transition temperature of −60 [° C.] or higher and 0 [° C.] or lower is used. With such a configuration, it is possible to exhibit better low-temperature fixability and heat-resistant storability to the toner than the aspect G.

[Aspect I]
Aspect I is the toner according to Aspect H, wherein the toner particles include a material containing a second amorphous polyester resin in addition to the first amorphous polyester resin which is the amorphous polyester resin. The glass transition temperature of the second amorphous polyester resin is 40[° C.] or higher and 70[° C.] or lower, and the glass transition temperature of the first temperature rise in differential scanning calorimetry of the toner particles is 20. It is characterized by using a material having a temperature of [° C.] or more and 50 [° C.] or less. With such a configuration, it is possible to exhibit even better low-temperature fixability and heat-resistant storage stability than the aspect H for the toner.

[Aspect J]
Aspect J is characterized in that, in any one of Aspects A to I, a plurality of protrusions are provided on the inner wall of the circulation conveyance path. With such a configuration, the resin coating layer of the carrier can be favorably abraded over time due to the plurality of protrusions.

[Aspect K]
Aspect K is a method according to Aspect J, wherein a screw member that conveys the developer in the rotation axis direction along with the rotation of itself is used as the conveyer, and at least the tip of the spiral blade of the screw member is made of a metal material. It is characterized by being configured. With such a configuration, the resin coating layer of the carrier can be favorably abraded with time by the blade tip portion of the screw member.

[Aspect L]
Aspect L is, in any one of Aspects A to K, after passing through a position facing the circulation conveyance path along with the surface movement, of the entire area of the peripheral surface of the developer carrier, A first layer thickness regulating member that regulates the layer thickness of the developer on the developer carrying member so as to face the region before entering the facing position of the developer via a predetermined gap; After passing through the position facing the latent image carrier along with the movement, the developer is opposed to a region before entering the position facing the circulation conveyance path with a gap narrower than the gap. A second layer thickness regulating member for regulating the layer thickness of the developer on the carrier is provided. In such a configuration, the resin coat layer of the carrier can be favorably abraded over time by promoting the stress application to the carrier by the action of the second layer thickness regulating member.

[Aspect M]
Aspect M is a latent image carrier that carries a latent image, a developing device that develops the latent image, a charging unit that charges the latent image carrier, and a latent image on the surface of the latent image carrier after charging. Among the latent image writing means for writing the data, the developing device, at least one of the latent image carrier, the charging means, and the latent image writing means are held as a unit on a common holding body. In the image unit, any one of modes A to L is used as the developing device.

[Aspect N]
Aspect N is a latent image carrier that carries a latent image, a developing device that develops the latent image, a charging unit that charges the latent image carrier, and a latent image on the surface of the latent image carrier after charging. In the image forming apparatus including a latent image writing unit that writes the image, any one of modes A to L is used as the developing device.

[Aspect O]
Aspect O is a latent image carrier that carries a latent image, a developing device that develops the latent image, a charging unit that charges the latent image carrier, and a latent image on the surface of the latent image carrier after charging. And a conveying means for conveying the developer containing the toner and the carrier in a circulating manner, a conveying body for conveying the developer in the circulating conveying path, and the circulating conveyance. After carrying the developer supplied from the path on its own surface, it is carried to the position facing the latent image carrier with the movement of its surface, and the developer carrying the latent image on the latent image carrier is developed. An image forming apparatus having a body in the developing device, wherein the surface of a particle core material is coated with a resin coat layer in which fine particles of a substance having an electronegativity of 1.4 or less are dispersed as the carrier. Use one
During the period from the initial stage until the image of 40,000 pages is developed, a stress is applied to the carrier to increase the abundance ratio of the fine particles on the surface of the carrier in the developing device from the initial stage. It is a thing.

1Y, 1M, 1C, 1K: photoconductor (latent image carrier)
5: Developing device 12: Exposure device (latent image writing means)
51: developing sleeve (developer carrier)
53: Supply and recovery screw (conveyor)
53a: Supply and recovery conveyance path (part of circulation conveyance path)
54: Stirring and conveying screw (conveyor)
54a: Agitation transport path (part of circulation transport path)
C _a1 : Core material (particle core material)
C _a2 : resin coat layer

JP, 2009-47886, A Patent No. 5534409

Claims (15)

A circulation transport path for circulating and transporting a developer containing toner and a carrier, a transport body for transporting the developer in the circulation transport path, and a developer supplied from the circulation transport path on its own surface. A developing method for a developing device , comprising: a developer carrier that carries the latent image on the latent image carrier by carrying it to a position opposite to the latent image carrier as the surface moves. ,
As the carrier, a resin coat layer in which fine particles of barium sulfate are dispersed is used, which is coated on the surface of the particle core material.
A developing method , wherein stress is applied to the carrier during the period from the initial stage until the image of 40,000 pages is developed, which stress increases the abundance ratio of the barium sulfate fine particles on the surface of the carrier from the initial stage . The developing method according to claim 1,
A development method , wherein the barium sulfate fine particles have a volume average particle diameter of 300 [nm] or more and 900 [nm] or less. The developing method according to claim 1 or 2,
The developing method , wherein the resin coat layer is made of a resin material containing an aminosilane coupling agent, as the carrier. The developing method according to any one of claims 1 to 3,
A development method , wherein the toner has a loss elastic modulus at 80 [° C.] of 1.9×10 ⁵ [Pa] or less. The developing method according to claim 4,
The toner having a storage elastic modulus at 50 [° C.] of 1.0×10 ⁷ [Pa] or more and a loss elastic modulus at 160 [° C.] of 2.1×10 ³ [Pa] or less. A developing method characterized by using . The developing method according to claim 4 or 5,
A development method characterized in that toner particles made of a material containing an amorphous polymer resin and a crystalline polymer resin are used as the toner . The developing method according to claim 6,
As the toner, a developing method which comprises using those differences between the first heating of the glass transition temperature and heating the second time in the glass transition temperature in a differential scanning calorimetry of the toner particles is 10 [° C.] or higher .. The developing method according to claim 7,
As the toner, the toner particles are made of a material containing an amorphous polyester resin, the amorphous polyester resin has a branched structure, and the glass transition temperature of the amorphous polyester resin is −60. A developing method using a material having a temperature of [° C.] or more and 0 [° C.] or less. The developing method according to claim 8,
As the toner, the toner particles are made of a material containing a second amorphous polyester resin in addition to the first amorphous polyester resin which is the amorphous polyester resin. The glass transition temperature of the polyester resin is 40[° C.] or higher and 70[° C.] or lower, and the first glass transition temperature in the differential scanning calorimetry of the toner particles is 20[° C.] or higher, 50[° C.] or higher. ] The following developing method is used. The developing method according to any one of claims 1 to 9,
A developing method characterized in that a plurality of protrusions are provided on an inner wall of the circulation conveyance path. The developing method according to claim 10,
As the carrier, using a screw member that conveys the developer in the rotation axis direction with the own rotation, and characterized in that at least the blade tip of the spiral blade in the screw member is constituted by a metallic material development Way . The developing method according to any one of claims 1 to 11,
Of the entire area of the peripheral surface of the developer carrier, after passing through the position facing the circulation conveyance path due to the surface movement and before entering the position facing the latent image carrier, A first layer thickness regulating member that regulates the layer thickness of the developer on the developer carrying member so as to face each other with a gap therebetween, and a facing position of the latent image carrying member with the surface movement in the entire area. After passing through the first and second positions, the layer thickness of the developer on the developer carrying member is regulated so as to face the area before entering the position facing the circulation conveyance path with a gap narrower than the gap. A developing method comprising a two-layer thickness regulating member. A latent image carrier that carries a latent image, a developing device that develops the latent image, a charging unit that charges the latent image carrier, and a latent image that writes the latent image on the surface of the latent image carrier after charging. of the writing means, and the developing device, the latent image bearing member, said charging means, and work of the image forming units held in a common holding member at least one as a unit in the latent image writing means The image method,
An image forming method, wherein the developing method according to claim 1 is used as a developing method of the developing device . A latent image carrier that carries a latent image, a developing device that develops the latent image, a charging unit that charges the latent image carrier, and a latent image that writes the latent image on the surface of the latent image carrier after charging. An image forming method of an image forming apparatus , comprising:
An image forming method, wherein the developing method according to claim 1 is used as a developing method of the developing device . A latent image carrier that carries a latent image, a developing device that develops the latent image, a charging unit that charges the latent image carrier, and a latent image that writes the latent image on the surface of the latent image carrier after charging. A circulation carrier path that includes a writing unit and that circulates and conveys a developer containing toner and a carrier, a carrier that conveys the developer in the circulation carrier path, and a circulation carrier path that supplies the developer. And carrying a developer on its surface, and carrying the developer to a position facing the latent image carrier along with its surface movement to develop the latent image on the latent image carrier. An image forming method for an image forming apparatus included in a developing device, comprising:
As before Kiki Yaria, using those coated with a resin coating layer obtained by dispersing barium sulfate fine particles on the surface of the particle core,
Within the period from the initial stage until the image of 40,000 pages is developed, a stress is applied to the carrier so as to increase the abundance ratio of the barium sulfate fine particles on the surface of the carrier in the developing device from the initial stage. Image forming method.

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