JP6089804B2 - Developer - Google Patents

Description

  One embodiment of the present invention relates to a developer, a container containing a developer, an image forming apparatus, a process cartridge, and a replenishment developer.

  In recent years, the technology of electrophotographic copying machines and printers is rapidly expanding from monochrome to full color, and the full color market tends to expand. When forming a color image, an electrostatic latent image is formed on the photosensitive member, and three-color toners of yellow, magenta, and cyan, or four-color toners and blacks added with black, and a static image are used. After developing the electrostatic latent image to form a toner image, the toner image is transferred to a recording medium and fixed.

  However, when used for a long time, there is a problem that the influence of the history by the image becomes large.

  Patent Document 1 discloses a magnetic carrier for an electrophotographic developer comprising spherical magnetic composite particles formed by binding ferromagnetic iron oxide particles with a phenol resin as a binder. At this time, the spherical magnetic composite particles have a surface ten-point average roughness Rz of 0.3 to 2.0 μm.

  However, there is a problem that carrier adhesion occurs when used for a long time.

  One embodiment of the present invention provides a developer capable of reducing the influence of image history and suppressing the occurrence of carrier adhesion even when used for a long period of time, in view of the above-described problems of the prior art. For the purpose.

In one embodiment of the present invention, the developer includes a toner and a carrier, and the toner includes base particles including a colorant, a release agent, and a binder resin, and a non-spherical external additive. In the carrier, a protective layer containing a resin and conductive particles is formed on the surface of core particles in which magnetic particles are dispersed in a binder resin, and the average height difference of the protective layer is 0.02 μm or more. 0μm is less than or equal to.

  According to an embodiment of the present invention, it is possible to provide a developer capable of reducing the influence of image history even when used for a long period of time and suppressing the occurrence of carrier adhesion.

FIG. 4 is a schematic diagram illustrating a state in which toner approaches a carrier surface. FIG. 6 is a schematic diagram illustrating a state where toner is held on a carrier surface. FIG. 6 is a schematic diagram illustrating a normal toner. FIG. 4 is a schematic diagram illustrating a state in which an external additive of toner is rolled into a concave portion of a base particle. FIG. 4 is a schematic diagram illustrating a state where the toner and the carrier illustrated in FIG. 3 are in contact with each other. It is a schematic diagram showing a contact state between the carrier and the external additive of the toner when the ratio of the arithmetic average roughness Ra of the carrier to the arithmetic average roughness Ra of the core particles is less than 0.60. It is a schematic diagram showing the contact state between the carrier and the external additive of the toner when the ratio of the arithmetic average roughness Ra of the carrier to the arithmetic average roughness Ra of the core particles is close to 1.00 (when there are few fine particles). It is a schematic diagram showing the contact state between the carrier and the external additive of the toner when the ratio of the arithmetic average roughness Ra of the carrier to the arithmetic average roughness Ra of the core particles is close to 1.00 (when the fine particles are small). It is a perspective view showing an example of the resistance measurement cell used for the measurement of the electrical resistivity of a carrier. FIG. 3 is a schematic diagram of a toner containing a spherical external additive. FIG. 4 is a schematic diagram illustrating a state in which an external additive rolls in a toner containing a spherical external additive. FIG. 3 is a schematic diagram of a toner containing a non-spherical (spindle-shaped) external additive. FIG. 6 is a schematic diagram illustrating a state in which an external additive is difficult to roll in a toner containing a non-spherical (spindle-shaped) external additive. It is a schematic diagram of a toner containing a non-spherical external additive (fusing particles). FIG. 4 is a schematic diagram illustrating a state in which an external additive is difficult to roll in a toner containing a non-spherical external additive (fusing particles). FIG. 6 is a schematic diagram illustrating a state in which contact between the toner and the carrier is reduced by rolling of the external additive. FIG. 6 is a schematic diagram showing a state in which the distance between the base particle and the developing sleeve is shortened. FIG. 5 is a schematic diagram showing a state in which the distance between the base particle and the developing sleeve is maintained. It is a photograph which shows an example of an external additive. It is a photograph which shows an example of an external additive. It is a photograph which shows an example of an external additive. It is a photograph which shows an example of an external additive. It is a photograph which shows an example of an external additive. It is the schematic which shows an example of the apparatus at the time of manufacturing coalesced particle by a dry process. It is a figure which shows an example of a developing device. 1 is a diagram illustrating an example of an image forming apparatus. It is a figure which shows the other example of an image forming apparatus. It is a figure which shows an example of a process cartridge. It is a figure which shows an example of the normal image and abnormal image in a longitudinal belt chart. It is a figure explaining the measuring method (blow-off method) which measures the charge amount of a developing agent.

  Next, the form for implementing this invention is demonstrated with drawing.

  The generation mechanism of the hysteresis phenomenon (ghost phenomenon) is not clear in detail, but is considered as follows. The toner adheres to the developer carrying member according to the immediately preceding image history, and the toner development amount of the next image varies depending on the potential of the toner attached on the developing sleeve. That is, it is considered that the toner development amount of the next image varies depending on the immediately preceding image history.

  More specifically, in the non-image area, a potential is formed to move the toner from the photoreceptor toward the developing sleeve, contrary to the image area, so that the toner adheres onto the developing sleeve (on the developing sleeve). Toner adheres to the toner). When the image portion is developed at the next development in a state where the toner is attached on the developing sleeve in this way, the toner attached on the developing sleeve is charged, so that the developing potential is equal to the potential of the toner on the developing sleeve. This increases the amount of toner development. Further, since the toner adhering to the developing sleeve is consumed at the time of development, the amount of adhering toner is not constant and varies depending on the history of the immediately preceding image. That is, when there is a non-image portion or a paper-to-paper gap immediately before, development of the subsequent image portion causes the above-described development potential to increase, and the subsequent image density increases. On the other hand, when the immediately preceding image is an image having a large image area, the toner adhering to the developing sleeve is consumed when the immediately preceding image is developed, and the effect of increasing the development potential described above is reduced. Concentration does not increase.

  As described above, the history phenomenon is a phenomenon in which the toner adhesion amount on the developing sleeve fluctuates due to the influence of the immediately preceding image, and the density fluctuation of the next image appears due to the fluctuation.

  Further, it has been clarified that, in use over a long period of time, the above-described phenomenon is worsened by the deterioration of the toner, that is, the increase in the adhesion force of the toner due to the embedding and detachment of the toner.

  That is, the toner is designed to develop on the photosensitive member by reducing the adhesion force between the developing sleeve and the carrier with an external additive.

  The adhesion force to the developing sleeve and the carrier will be further described. The adhesion force to the developing sleeve is reduced as shown in FIG. 14 due to the spacer effect by the external additive. Similarly, the non-electrostatic adhesion force is also reduced for the carrier, but by using the non-electrostatic interaction as shown in FIG. 1A and FIG. 1B, it adheres to the carrier rather than the developing sleeve. I have control.

  When the external additive of the toner is buried or detached, the developing sleeve is close to the developing sleeve as shown in FIG. 13, thereby increasing the adhesion force due to van der Waals force or the like, while the adhesion force with the carrier is As shown in FIG. 12, the toner is reduced, and as a result, the toner tends to remain on the developing sleeve, and the ghost phenomenon is accelerated.

  As a cause of embedding and detachment of the external additive of the toner, contact with a carrier having a large specific gravity is considered, and suppression of the above phenomenon was examined by using a carrier having a low specific gravity.

  However, the carrier having a low specific gravity has deteriorated the adhesion of the carrier because the magnetic binding force from the developing sleeve is low.

  Here, the carrier adhesion greatly contributes to the improvement of the carrier adhesion in the non-image area, and will be described below.

  It is known that the cause of non-image part carrier adhesion is due to the counter charge generated on the carrier. However, as a mechanism for generating the counter charge, physical contact with the photoreceptor and potential in the non-image part As a result of intensive studies, it has been clarified that toner is caused by drift.

  The carrier adhesion on the non-image part will be described in detail.

  In the image area, a potential is formed so that toner (here, negatively charged) moves from the developing sleeve to the photosensitive member. On the other hand, in the non-image portion, a reverse potential, that is, a potential that the toner moves onto the developing sleeve is formed so that the toner (minus charge) does not move (scatter and dust) onto the photoreceptor. Since the carrier is positively charged, if a positive charge is generated, a force that moves to the photoconductor acts, and the carrier adheres to the photoconductor, resulting in non-image portion carrier adhesion.

  However, when the toner density is controlled to a general toner concentration (TC7 to 10%) in the non-image area, the toner adheres to the surface of the carrier in a state close to 100% coating, and therefore, it is added to the carrier. There is no charging. However, it has been revealed that the toner moves particularly from the tip of the carrier ear due to the force due to the potential in the non-image area and the physical rubbing when the tip of the carrier contacts the photoreceptor.

  As the toner moves, positive charge (counter charge) is generated in the carrier, and the toner moves to the photosensitive member due to the potential of the non-image portion.

  As a result of intensive studies to achieve fluctuations in image density and deterioration of non-image carrier adhesion, the present inventors set the concavo-convex shape of the carrier and the concavo-convex shape of the protective layer to be within a specified range. Since the carrier does not roll easily, the amount of toner adhering to the developing sleeve is stabilized, and the unevenness of the carrier has a predetermined value, so that the coated carrier partially reduces the resistance of the core particles. It is possible to make a near low resistance part, and the toner adhering to the developing sleeve at the time of non-image is less likely to be consumed at the time of printing, and the external additive of the toner is non-spherical. It is possible to suppress the transfer of toner onto the developing sleeve by electrical interaction, and by reducing the specific gravity of the carrier, deterioration such as embedding and detachment of the external additive of the toner is suppressed, and fluctuations in image density are suppressed. It was finding the Rukoto.

  Furthermore, by making the uneven shape of the carrier, the unevenness of the protective layer, and the external additive of the toner non-spherical, the movement of the toner from the carrier is suppressed by the contact with the photoreceptor and the potential of the non-image area, and the counter charge It has been found that a developer that suppresses the deterioration of the carrier adhesion in the non-image area over a long period of time can be obtained by suppressing the generation.

  The developer includes a toner and a carrier. The toner includes base particles including a colorant, a release agent, and a binder resin, and a non-spherical external additive. The carrier includes magnetic particles in a binder resin. Dispersed, and unevenness having an average height difference of 0.02 μm to 3.0 μm is formed on the surface.

(Career)
The carrier includes core particles and a protective layer formed on the core particles, and further includes other components as necessary.

  By reducing the hazard to the toner by reducing the specific gravity of the carrier, the deterioration of the external additive of the toner is suppressed, the increase in the adhesion force (electrostatic and non-electrostatic) of the toner is suppressed, and the low specific gravity is also reduced. The toner moves from the carrier by strengthening the non-electrostatic bond due to the interaction between the carrier and the irregularities of the protective layer of the carrier and the irregularities of the external additive of the toner. It aims to make it difficult to do.

  Specifically, in the carrier, the contact between the carrier and the toner is increased by the unevenness of the surface of the carrier derived from the core particle of the carrier, and the fine unevenness due to the particles contained in the protective layer is provided on the surface of the protective layer. It is intended to increase the toner holding power of the carrier by contact with the toner external additive.

  By increasing the toner holding power of the carrier, in the non-image area, when a bias is applied in the direction from the photoconductor to the developing sleeve, the toner is prevented from adhering to the developing sleeve, and a ghost phenomenon due to image history is prevented. It is thought that it is suppressing.

  Hereinafter, improvement of the toner holding force of the carrier will be described with reference to the drawings. FIG. 1A is a schematic diagram illustrating a state in which the toner approaches the carrier surface. FIG. 1B is a schematic diagram illustrating a state where the toner is held on the surface of the carrier.

  In FIG. 1B, as indicated by two round broken lines, the toner 101 and the carrier are in contact with each other at a plurality of locations due to the unevenness derived from the core particles 111 of the carrier. In addition, in the range indicated by each round broken line, the carrier and the external additive of the toner 101 are in contact with each other due to fine unevenness formed by the resin 112 and the particles 113 included in the protective layer of the carrier. As described above, since the carrier and the toner have many contact points, the non-electrostatic bond is strengthened by the interaction between the unevenness of the carrier and the unevenness of the toner, and the toner holding power of the carrier is increased. It is considered a thing.

-Arithmetic average roughness Ra of carrier-
The arithmetic average roughness Ra in the carrier is 0.50 μm to 0.90 μm, and preferably 0.60 μm to 0.85 μm.

  When the arithmetic average roughness Ra is less than 0.50 μm, the carrier on the developing sleeve is easy to rotate and the developer does not follow the rotation speed of the developing sleeve, so that the developer slips on the developing sleeve. May end up. As a result, there is a speed difference between the developing sleeve and the developer, and the amount of toner adhering to the developing sleeve during non-image may increase. Further, since the low resistance portion, that is, the protective layer is thin and there are few portions near the core particle exposure, the toner adhering to the developing sleeve at the time of non-image is consumed at the time of printing, and the amount of toner on the developing sleeve is reduced. May fluctuate significantly.

  On the other hand, when the arithmetic average roughness Ra exceeds 0.90 μm, the unevenness of the carrier itself is too large, and the wear of the carrier is biased toward the convex portion, so that the wear of the protective layer may be remarkable.

  Further, in relation to the toner, when the arithmetic average roughness Ra exceeds 0.90 μm, the unevenness of the carrier itself is too large, so that the hazard for the toner becomes high, and the external additive of the toner becomes a base particle. The embedding and the toner external additive are promoted to roll into the recesses of the base particles, and the function of the toner external additive is easily lost.

  Here, the arithmetic average roughness Ra represents unevenness on the surface of the carrier, and contributes to the amount of toner adhering to the developing sleeve.

  Here, FIG. 2 is a schematic view showing a normal toner. FIG. 3 is a schematic diagram illustrating a state in which the external additive of the toner is rolled to the concave portion of the base particle. FIG. 4 is a schematic diagram illustrating a state where the toner and the carrier illustrated in FIG. 3 are in contact with each other.

  In the normal toner 101 shown in FIG. 2, the external additive 103 is uniformly distributed on the surface of the base particle 102. On the other hand, in the toner 101 shown in FIG. 3, the distribution of the external additive 103 on the surface of the base particle 102 is non-uniform as a result of the external additive 103 rolling into the recesses of the base particle 102. The toner shown in FIG. 3 is easily obtained by contact with a carrier having large irregularities. The toner shown in FIG. 3 has a non-uniform distribution of the external additive 103 on the surface of the base particle 102, and therefore, as shown in FIG. It is difficult to obtain a good contact state between the external additive and the carrier. Even when the external additive is buried in the toner, it is difficult to obtain a good contact state between the toner and the carrier. When a spherical external additive is used, the toner is more likely to roll or bury, and the tendency to make it difficult to obtain a good contact state increases.

  The arithmetic average roughness Ra can be obtained by the following measuring method. Using an OPTELICS C130 manufactured by LASERTEC, the image was captured with an objective lens magnification of 50 times and a Resolution of 0.20 μm, and the observation area was 10 μm × 10 μm centered on the top of the carrier and 100 carriers were measured Use the value obtained.

<Core particles>
A method for producing core particles will be described.

  That is, the spherical magnetic composite particles constituting the core particles are obtained by reacting phenols and aldehydes in the presence of a basic catalyst in the presence of a basic catalyst in an aqueous medium. Can be obtained.

  First, the ferromagnetic iron oxide particles will be described.

  Ferromagnetic iron oxide particles contained in the carrier have irregularities on the surface of the core particles, and increase the surface area of the core particles to increase the adhesion between the protective layer and the core particles. Also, the irregularities after coating the protective layer Therefore, it is composed of ferromagnetic iron oxide particles a and ferromagnetic iron oxide particles b having different average particle diameters.

  When the average particle diameter of the ferromagnetic iron oxide particles a having a relatively large average particle diameter is ra and the average particle diameter of the ferromagnetic iron oxide particles b having a relatively small average particle diameter is rb, the irregularities on the surface of the core particles On the other hand, the average particle diameter ratio ra / rb is important. The ratio of the average particle diameter ra / rb is more preferably 1.1 to 10.0, still more preferably 1.1 to 9.0, and still more preferably 1.2 to 5.0.

  The mixing ratio of the ferromagnetic iron oxide particles “a” and the ferromagnetic iron oxide particles “b” contained in the carrier is not particularly limited, but generally the content of the ferromagnetic iron oxide particles “a” is smaller than that of the ferromagnetic iron oxide particles “b”. It is advantageous in that it has a spherical shape and appropriate irregularities on the surface. The total amount of the ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b is preferably 100 parts by mass, and the ferromagnetic iron oxide particles a are preferably contained within a range of 1 to 50 parts by mass, more preferably 10 to 45 parts by mass. Part.

  When the ferromagnetic iron oxide particles a are less than 1 part by mass, the ferromagnetic iron oxide particles b forming the core portion are likely to appear on the surface of the particles, so that the surface layer portion made of the ferromagnetic iron oxide particles a is not formed. Sufficient surface irregularities cannot be obtained.

  The average particle diameter ra of the ferromagnetic iron oxide particles a is preferably 0.25 μm to 5.0 μm. When the average particle diameter ra is less than 0.25 μm, sufficient unevenness cannot be obtained on the magnetic carrier surface. In addition, when the average particle diameter ra exceeds 5.0 μm, the load applied to the convex portions of the surface irregularities becomes large, and the ferromagnetic iron oxide particles a are desorbed to remove the irregularities, or coat the protective layer. Sufficient damage durability against subsequent stirring stress cannot be obtained. A more preferable average particle diameter ra is 0.25 to 2.0 μm.

  The average particle diameter rb of the ferromagnetic iron oxide particles b is preferably 0.05 μm to 0.25 μm. When the average particle diameter rb is less than 0.05 μm, the cohesive force of the magnetic iron oxide particles b becomes large, and it becomes difficult to produce a magnetic carrier. On the other hand, when the average particle size rb exceeds 0.25 μm, there is no difference in particle size from the ferromagnetic iron oxide particles a, and it becomes difficult to form a stable surface layer portion with the ferromagnetic iron oxide particles a.

  The ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b are magnetic iron oxide particles such as magnetite particles and maghematite particles.

  The particle shape of the ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b is any one selected from spherical, hexahedral, octahedral, polyhedral, and indeterminate, and the combination may be the same shape or shape. You may combine things with different.

  The ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b have a ferromagnetic surface coated with one or more compounds selected from Al, Mg, Mn, Zn, Ni, Cu, Ti, and Si. Iron oxide particles may be used.

  When using the one coated with the above compound, the amount of the coating element present on the surface of the ferromagnetic iron oxide particles is preferably 0.35 to 4.0% by mass with respect to the total amount of the ferromagnetic iron oxide particles, More preferably, it is 0.4-3.5 mass%.

  Easy magnetic carrier with high electrical resistance by using ferromagnetic iron oxide particles whose surface is coated with one or more compounds selected from Al, Mg, Mn, Zn, Ni, Cu, Ti, Si Can get to.

  Ferromagnetic iron oxide particles whose surface is coated with one or more compounds selected from Al, Mg, Mn, Zn, Ni, Cu, Ti and Si can be obtained by the following production method.

  The surface-coated ferromagnetic iron oxide particles produce magnetite core particles according to a conventional method, and then maintain the slurry containing the core particles in a temperature range of 70 to 95 ° C. to control the pH of the slurry. Then, after adding the covering element salt at a rate of 0.015 mass% / min or less with respect to the core particles, aging for 30 minutes or more, and then adjusting the pH, and then washing and drying according to a conventional method, Can be obtained.

  The core particles for obtaining ferromagnetic iron oxide particles with coated surfaces can be selected in various shapes and particle sizes from the viewpoints of required magnetic properties and dispersibility. However, from the viewpoint of more uniformly performing the surface treatment, it is preferable that the core particle slurry does not contain a substance that is likely to be an inhibitor of the surface treatment, such as unreacted iron hydroxide particles.

There are various methods for obtaining the slurry containing the core particles. For example, by controlling the pH during the oxidation reaction of the Fe ²⁺ aqueous solution to a predetermined value, octahedrons, polyhedrons, hexahedrons, spheres, irregularities A shape can be obtained.

  Moreover, the core particle of a desired particle diameter can be obtained by controlling the growth conditions of the particles during the oxidation reaction.

  In addition, the surface smoothness of the core particles controls the growth conditions at the end of the oxidation reaction, and as is generally known, components such as silica components, aluminum components, calcium components, and spinel ferrite crystal structures such as zinc and manganese It is also possible to control by adding a component that easily forms a slag.

As the Fe ²⁺ aqueous solution, for example, a general iron compound such as ferrous sulfate or ferrous chloride can be used.

  Moreover, aqueous solutions, such as sodium hydroxide and sodium carbonate, can be used for the alkaline solution for obtaining iron hydroxide or as a pH adjuster.

  Each raw material may be selected in consideration of economy and reaction efficiency.

  The pH of the slurry during the Al surface treatment is preferably 8.0 to 9.0, and more preferably 8.2 to 8.8. When the pH of the slurry is less than 8.0, the Al component is not coated on the surface of the core particles and is precipitated by the Al compound alone, resulting in a low electrical resistance value, a high BET specific surface area value, and hygroscopicity. It becomes high and is not preferable. Even when the pH of the slurry exceeds 9.0, the Al component is not coated on the surface of the core particles and is precipitated by the Al compound alone, resulting in a low electrical resistance value, and a high BET specific surface area value. Is undesirably high.

  The pH of the slurry during Mg surface treatment is 9.5 to 10.5, the pH of the slurry during Mn surface treatment is 8.0 to 9.0, and the pH of the slurry during Zn surface treatment is 8.0 to 9.0. The pH during Ni surface treatment is 7.5 to 8.5, the pH during Cu surface treatment is 6.5 to 7.5, the pH during Ti surface treatment is 8.0 to 9.0, and during Si surface treatment The pH of is preferably 6.5 to 7.5. When the pH is out of the above range, the electric resistance value is low, and the hygroscopicity is high, which is not preferable.

  The temperature range of the slurry for surface-treating the coating component is preferably 70 to 95 ° C. When the temperature of the slurry is less than 70 ° C., the BET specific surface area value is high, which is not preferable from the viewpoint of hygroscopicity of the ferromagnetic iron oxide particles themselves. Although the condition value is not particularly limited, it is an aqueous slurry, and therefore the upper limit is about 95 ° C. in consideration of productivity and cost.

  It is preferable to add the coating compound to the slurry containing the core particles at a coating element content of 0.015% by mass / min or less with respect to the core particles. More preferably, it is added at a coating element content of 0.01% by mass / min or less with respect to the core particles. When the coating element is added at a rate higher than 0.015% by mass / min, the coating compound is not coated on the surface of the core particles and precipitates alone, resulting in a low electrical resistance value of the ferromagnetic iron oxide particles themselves, and the BET ratio. The surface area value becomes large and the ferromagnetic iron oxide particles themselves have high hygroscopicity. The lower limit is not particularly limited, but considering productivity, the lower limit is 0.002% by mass / min.

  After adding the coating compound, aging is preferably performed for 30 minutes or more in order to uniformly treat the coating compound on the surface of the core particles. The upper limit is not particularly limited, but considering productivity, the upper limit is about 240 minutes.

  The slurry is preferably well stirred.

  After aging, it is preferable to control the pH of the slurry in the range of 4.0 to 10.0. More preferably, the pH of the slurry is in the range of 6.0 to 8.0. When the pH is less than 4.0, it is difficult to uniformly form the coating compound layer on the core particle surface. Even when the pH exceeds 10.0, it is difficult to uniformly form the coating compound layer on the core particle surface.

  In controlling, the slurry is preferably well stirred.

  After the reaction, it may be washed with water and dried according to a conventional method.

  The surfaces of the ferromagnetic iron oxide particles “a” and the ferromagnetic iron oxide particles “b” are preferably subjected to lipophilic treatment in advance.

  By carrying out the oleophilic treatment, it is possible to obtain a magnetic carrier having a spherical shape more easily.

  In the oleophilic treatment, the ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b are treated with a coupling agent such as a silane coupling agent or a titanate coupling agent, or ferromagnetic in an aqueous solvent containing a surfactant. A method in which iron oxide particles are dispersed and a surfactant is adsorbed on the particle surface is suitable.

  Examples of the silane coupling agent include those having a hydrophobic group, an amino group, and an epoxy group. Examples of the silane coupling agent having a hydrophobic group include vinyl trichlorosilane, vinyl triethoxysilane, vinyl tris (β- Methoxy) silane and the like.

  As the silane coupling agent having an amino group or an epoxy group, the silane coupling agent having an amino group or the silane coupling agent having an epoxy group may be used.

  As the titanate coupling agent, isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate or the like may be used.

  As the surfactant, commercially available surfactants can be used, and those having a functional group capable of binding to a ferromagnetic iron oxide particle or a hydroxyl group on the particle surface are desirable, and the ionicity is cationic or anionic. Is preferred.

  In view of adhesiveness with the phenol resin, treatment with a silane coupling agent having an amino group or an epoxy group is preferable.

  The treatment amount of the coupling agent or surfactant is preferably 0.1 to 10% by mass with respect to the ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b.

  The ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b may be preliminarily mixed and then subjected to the oleophilic treatment or separate treatment. It is essential to use the iron particles a and the ferromagnetic iron oxide particles b in a sufficiently mixed state (hereinafter, the state in which the ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b are sufficiently mixed is referred to as “ Blend powder).

  A method for producing spherical magnetic composite particles comprising a blend powder and a phenol resin is as follows.

  As phenols, in addition to phenol, alkylphenols such as m-cresol, p-cresol, p-tert-butylphenol, o-propylphenol, and a part or all of alkyl groups are substituted with chlorine atoms or bromine atoms. Examples thereof include compounds having a phenolic hydroxyl group such as halogenated phenols.

  The total content of the blend powder in the spherical magnetic composite particles as phenols is preferably 80 to 99% by mass with respect to the spherical magnetic composite particles. When the content is less than 80% by mass, the resin content increases, It becomes easy to do. If it exceeds 99% by mass, the resin content is insufficient and sufficient strength cannot be obtained. More preferably, it is 85-99 mass%.

  Examples of aldehydes include formaldehyde, acetaldehyde, furfural, glyoxal, acrolein, crotonaldehyde, salicylaldehyde, and glutaraldehyde in the form of either formalin or paraaldehyde, with formaldehyde being most preferred.

  The molar ratio of aldehydes to phenols is preferably 1.0 to 4.0. When the molar ratio of aldehydes to phenols is less than 1.0, it is difficult to produce particles, Since hardening is difficult to proceed, the strength of the resulting particles tends to be weak. When it exceeds 4.0, there is a tendency that unreacted aldehydes remaining in the aqueous medium after the reaction increase. More preferably, it is 1.2-3.0.

  As a basic catalyst, the basic catalyst currently used for manufacture of the usual resole resin can be used. For example, ammonia water, hexamethylenetetramine, alkylamines such as dimethylamine, diethyltriamine, and polyethyleneimine can be mentioned, and ammonia water is particularly preferable.

  The basic catalyst is preferably 0.05 to 1.50 in molar ratio to phenols. If it is less than 0.05, curing does not proceed sufficiently and granulation becomes difficult. If it exceeds 1.50, it affects the structure of the phenolic resin, resulting in poor granulation properties, making it difficult to obtain particles having a large particle size.

  Although the reaction is carried out in an aqueous medium, the solid content concentration in the aqueous medium is preferably 30 to 95% by mass, and particularly preferably 60 to 90% by mass.

  The reaction solution to which the basic catalyst has been added is heated to a temperature range of 60 to 95 ° C., and reacted at this temperature for 30 to 300 minutes, preferably 60 to 240 minutes, followed by a polycondensation reaction of a phenol resin and curing.

  At this time, in order to obtain spherical magnetic composite particles with high sphericity, it is desirable to raise the temperature gently.

  The rate of temperature rise is preferably 0.3 to 1.5 ° C / min, more preferably 0.5 to 1.2 ° C / min.

  At this time, it is desirable to control the stirring speed in order to control the particle size.

  The stirring speed is preferably 100 to 1000 rpm.

  After curing, when the reaction product is cooled to 40 ° C. or lower, the blended powder is dispersed in the binder resin, and the structure thereof is the water dispersion of the spherical magnetic composite particles in which the surface layer portion is formed by the ferromagnetic iron oxide particles a. A liquid is obtained.

  The aqueous dispersion containing the spherical magnetic composite particles is filtered and solid / liquid is separated according to a conventional method of centrifugation, followed by washing and drying to obtain spherical magnetic composite particles.

  Further, it is desirable that the carrier is coated as described later.

-Arithmetic average roughness Ra of core particles-
The arithmetic average roughness Ra of the core particles defines the surface roughness of the core particles.

  There is no restriction | limiting in particular as arithmetic mean roughness Ra of the said core particle, Although it can select suitably according to the objective, 0.50 micrometer-1.50 micrometer are preferable, and 0.60 micrometer-1.30 micrometer are more preferable. When the arithmetic average roughness Ra is less than 0.50 μm, it may be difficult to obtain a desired surface roughness when the carrier is produced. When the arithmetic average roughness Ra exceeds 1.50 μm, the carrier is produced. The surface roughness may become too large. On the other hand, when the arithmetic average roughness Ra is within the more preferable range, it is advantageous in that the amount of toner deposited on the developing sleeve can be more controlled when the carrier is manufactured.

  The value of the arithmetic average roughness Ra can be obtained by the same method as the method for measuring the arithmetic average roughness Ra described above.

  The ratio of the arithmetic average roughness Ra of the carrier to the arithmetic average roughness Ra of the core particles is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 0.60 to 1.00, 0.70 to 0.90 is more preferable. When the ratio is less than 0.60, the irregularities of the core particles are filled when the carrier is produced, and the amount of toner adhering to the developing sleeve may increase. That the ratio is close to 1.00 means that the unevenness of the core particle and the unevenness of the carrier are close. In this case, the unevenness of the carrier derived from the core particles makes it difficult to hold the toner on the carrier due to contact between the toner and the carrier at a plurality of points, and therefore the amount of toner adhering to the developer sleeve increases. There is. In addition, the filler responsible for durability in the protective layer is not sufficiently added, or even if added, the particle size is small, and the durability effect may be insufficient.

  On the other hand, when the ratio is within the more preferable range, it is advantageous in terms of both control of the amount of toner adhering to the developing sleeve and durability.

Here, FIG. 5 is a schematic diagram showing the contact state between the carrier and the external toner additive when the ratio is less than 0.60. As shown in FIG. 5, when the ratio is less than 0.60, the protective layer fills the irregularities of the core particles when manufacturing the carrier (forming the protective layer), and the carrier and toner Contact with external additives is reduced.
Therefore, the toner adhesion amount on the developing sleeve may increase.

  6 and 7 are schematic views showing the contact state between the carrier and the toner external additive when the ratio is close to 1.00. FIG. 6 shows a case where the fine particles are small, and FIG. 7 shows a case where the fine particles are small. As shown in FIGS. 6 and 7, when the ratio is close to 1.00, the carrier unevenness derived from the core particles can hold the toner in the carrier by contacting the toner and the carrier at a plurality of points. Since it is difficult, the amount of toner adhering to the developing sleeve may increase.

<Protective layer>
The protective layer contains a resin and particles, and further contains other components as necessary. The protective layer can be formed, for example, by applying a protective layer forming solution containing a resin and particles to the core particles.

  However, since a resin is used for the core particles, a protective layer is not necessarily required.

  The thickness of the protective layer can be controlled by the content of the resin with respect to the core particles. There is no restriction | limiting in particular as content with respect to the said core particle of the said resin in the said carrier, Although it can select suitably according to the objective, The point which can form a local low resistance state with the thickness of a protective layer And 0.5 mass%-3.0 mass% are preferable.

  There is no restriction | limiting in particular as the average thickness h of the said protective layer, Although it can select suitably according to the objective, 0.2 micrometer-2 micrometers are preferable, and 0.2 micrometer-0.5 micrometer are more preferable. When the average thickness is less than 0.2 μm, when the developer is stirred in the developing device, the core particles are easily exposed on the surface of the protective layer, and the change in resistance value may increase. Yes, if it exceeds 2 μm, the convex portions of the core particles are not exposed, and it may be difficult to create a local low resistance state. When the average thickness is within the preferable range, it is advantageous in that a carrier having a local low resistance state can be produced.

  The thickness of the protective layer can be controlled by the content of the resin with respect to the core particles.

  The average thickness h of the protective layer can be obtained from the average value by observing the cross section of the carrier using a transmission electron microscope (TEM), measuring the thickness of the resin portion of the protective layer covering the carrier surface, and the like. it can. Specifically, the distance from the core particle surface to the protective layer surface is measured at any 50 points from the carrier cross section, and the average of the measured values is obtained.

−Average height difference−
The average height difference of the protective layer is 0.02 μm to 3.0 μm, preferably 0.15 μm to 0.40 μm.

  When the average height difference is less than 0.02 μm, there is almost no unevenness due to particles on the surface of the carrier, and adhesion force due to minute contact between the carrier and the external additive of the toner is unlikely to occur. May become a cause of ghost phenomenon. Further, the toner may move from the surface of the carrier due to contact with the photoconductor or non-image potential, and non-image carrier adhesion may be deteriorated. Moreover, since the so-called filler effect is not sufficient, the wear resistance of the protective layer may be deteriorated. Further, since there is almost no unevenness on the surface of the carrier, scraping of the toner spent is not sufficient, and charging stability may be a problem. When the average height difference exceeds 3.0 μm, since the resin does not have sufficient force to restrain the particles, the separation of the particles and the abrasion of the resin based thereon may be a problem. In addition, the ghost phenomenon may be worsened due to an increase in toner transfer to the developing sleeve due to a decrease in the toner holding power of the carrier.

  Here, the average height difference of the protective layer represents unevenness caused by particles contained in the protective layer, and the toner moves onto the developing sleeve using the toner holding force due to contact with the external additive of the toner. This contributes to the suppression of the toner, the contact with the photoconductor and the movement of the toner from the surface of the carrier due to the non-image potential, the carrier resistance adjustment, the wear resistance, and the scraping of the toner spent.

  The average height difference can be measured, for example, by observing the cross section of the carrier using a transmission electron microscope (TEM) and measuring the thickness of the resin portion of the protective layer covering the carrier surface. Specifically, in the carrier cross section, the distance from the core particle surface to the surface of the protective layer is measured at any 50 points in the carrier cross section, and the average value of the 5 points from the large value of the obtained measurement value and the small value is small. The difference from the average value of 5 points from the value.

<Resin>
The resin is not particularly limited and may be appropriately selected depending on the purpose. For example, acrylic resin, amino resin, polyvinyl resin, polystyrene resin, halogenated olefin resin, polyester, polycarbonate, polyethylene, polyfluoride Fluorine such as vinyl, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymers of vinylidene fluoride and vinyl fluoride, terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers Examples include terpolymers and silicone resins. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is preferable.

  Moreover, as said resin, resin containing the hardened | cured material of the mixture containing a silane coupling agent and a silicone resin can also be used suitably.

  There is no restriction | limiting in particular as said silicone resin, According to the objective, it can select suitably. The silicone resin may be a commercially available product. Examples of the commercially available product include SR2410 (manufactured by Toray Dow Corning Silicone). These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as said resin, Although it can select suitably according to the objective, At least A part represented by the following general formula (A), and B part represented by the following general formula (B) A resin containing a cross-linked product obtained by hydrolyzing the containing copolymer to produce a silanol group for condensation is preferred.

However, in said general formula (A), R1 represents either a hydrogen atom or a methyl group, R2 represents a C1-C4 alkyl group, m represents the integer of 1-8, X represents a molar ratio in the copolymer and represents 10 mol% to 90 mol%.

However, in said general formula (B), R1 represents either a hydrogen atom or a methyl group, R2 represents a C1-C4 alkyl group, R3 represents a C1-C8 alkyl group. Represents any of a group and an alkoxy group having 1 to 4 carbon atoms, m represents an integer of 1 to 8, Y represents a molar ratio in the copolymer, and represents 10 mol% to 90 mol%. .

  The silane coupling agent can stably disperse the particles. There is no restriction | limiting in particular as said silane coupling agent, According to the objective, it can select suitably, (gamma)-(2-aminoethyl) aminopropyl trimethoxysilane, (gamma)-(2-aminoethyl) aminopropyl methyl dimethoxy. Silane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxy Silane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilazane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, octadecyldimethyl [3- ( Trimetoki Silyl) propyl] ammonium chloride, γ-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, allyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, dimethyldi Examples include ethoxysilane, 1,3-divinyltetramethyldisilazane, and methacryloxyethyldimethyl (3-trimethoxysilylpropyl) ammonium chloride. These may be used alone or in combination of two or more.

  As the silane coupling agent, an appropriately prepared product or a commercially available product may be used. Examples of the commercially available product include AY43-059, SR6020, SZ6023, SH6020, SH6026, SZ6032, SZ6050, AY43-310M, SZ6030, SH6040, AY43-026, AY43-031, sh6062, Z-6911, sz6300, sz6075, sz6079, sz6083, sz6070, sz6072, Z-6721, AY43-004, Z-6187, AY43-021 AY43-043, AY43-040, AY43-047, Z-6265, AY43-204M, AY43-048, Z-6403, AY43-206M, AY43-206E, Z6341, AY43-210MC, Y43-083, AY43-101, AY43-013, AY43-158E, Z-6920, Z-6940 (manufactured by Toray Silicone Co., Ltd.).

  There is no restriction | limiting in particular as content of the said silane coupling agent, Although it can select suitably according to the objective, 0.1 mass%-10 mass% are preferable with respect to the said resin. When the content is less than 0.1% by mass, the adhesion between the core particles or the particles and the resin is lowered, and the protective layer may fall off during long-term use. If it exceeds 50%, toner filming may occur during long-term use.

  The protective layer includes, for example, a silicone resin having a silanol group and / or a hydrolyzable functional group, a polymerization catalyst, and, if necessary, a resin other than a silicone resin having a silanol group and / or a hydrolyzable functional group, a solvent It can form using the composition for protective layers containing this.

  Specifically, it may be formed by condensing silanol groups while coating the core particles with the protective layer composition, or after coating the core particles with the protective layer composition, It may be formed by condensation.

  The method for condensing the silanol group while coating the core particles with the protective layer composition is not particularly limited. For example, the core particles are coated with the protective layer composition while applying heat, light, and the like. The method etc. are mentioned.

  Further, the method for condensing the silanol group after coating the core particles with the protective layer composition is not particularly limited and may be appropriately selected depending on the purpose. For example, the core layer is coated with the protective layer composition. The method of heating after coat | covering particle | grains etc. is mentioned.

<Particle>
There is no restriction | limiting in particular as said particle | grains, Although it can select suitably according to the objective, It is preferable that at least any one of an alumina, a silica, titanium, barium, tin, and carbon is included.

  As the particles, both conductive particles and non-conductive particles can be used, and the conductive particles and non-conductive particles may be used in combination.

  Here, the conductive particles refer to particles having a powder specific resistance of 100 Ω · cm or less, and the non-conductive particles refer to particles having a powder specific resistance exceeding 100 Ω · cm.

  The powder specific resistance can be measured, for example, as follows. 5 g of a sample is put in a cylindrical vinyl chloride tube having an inner diameter of 1 inch, and the upper and lower sides are sandwiched between electrodes. A pressure of 10 kg / cm 2 is applied to these electrodes by a press. Subsequently, an LCR meter (4216A, produced by Yokogawa-HEWLETT-PACKARD) is connected in this pressurized state. The resistance r (Ω) immediately after the connection is read and the total length L (cm) is measured with a caliper to calculate the powder specific resistance (Ω · cm). The calculation formula is shown in the following formula.

Powder specific resistance (Ω · cm) = {(2.54 / 2) 2 × π} × r / (L-11.35)
r: resistance immediately after connection L: full length when sample is filled 11.35: full length when sample is not filled The conductive particles are not particularly limited and can be appropriately selected according to the purpose. Conductive particles formed by layering tin dioxide, indium oxide, etc. on a substrate such as aluminum oxide, titanium dioxide, zinc oxide, silicon dioxide, barium sulfate, zirconium oxide, etc .; conductive particles formed using carbon black, etc. It is done. Among these, conductive particles formed by forming a layer of tin dioxide or indium oxide on a base of aluminum oxide, titanium dioxide, or barium sulfate are preferable.

  There is no restriction | limiting in particular as said nonelectroconductive particle, According to the objective, it can select suitably, For example, aluminum oxide, titanium dioxide, zinc oxide, silicon dioxide, barium sulfate, a zirconium oxide etc. are mentioned.

  There is no restriction | limiting in particular as a common logarithm of the powder specific resistance of the said particle | grains, Although it can select suitably according to the objective, -3 [log ((omega | ohm) * cm)]-3Log [log ((omega | ohm) * cm)] Is preferred. When the powder specific resistance is less than −3 [log (Ω · cm)], the resistance of the particles is too low, and thus the toner may not be sufficiently charged during frictional charging with the toner. When [log (Ω · cm)] is exceeded, the carrier resistance adjustment capability is not sufficient, and the edge effect and the fineness of the image may be deteriorated.

  The volume average particle diameter D of the particles is preferably 50 nm to 700 nm, and more preferably 300 nm to 600 nm. By having a particle size within the above range, particles are likely to come out from the surface of the protective layer, and it is easy to make a partial low resistance, and furthermore, it is easy to scrape the spent on the carrier surface and is excellent in wear resistance.

  The volume average particle diameter D of the particles can be measured using, for example, an ultracentrifugal automatic particle size distribution analyzer CAPA-700 (manufactured by Horiba, Ltd.). Specifically, the measurement is performed according to the following procedure.

  In a juicer mixer, 300 mL of a toluene solution is added to 30 mL of aminosilane (SH6020, manufactured by Toray Dow Corning Co., Ltd.). Add 6.0 g of the sample, set the mixer rotation speed to low and disperse for 3 minutes. An appropriate amount of the dispersion is added to 500 mL of a toluene solution prepared in advance in a 1,000 mL beaker and diluted. The obtained diluted solution is continuously stirred with a homogenizer. The volume average particle size is measured with an ultracentrifugal automatic particle size distribution analyzer CAPA-700 (manufactured by Horiba, Ltd.).

-Measurement conditions-
Measurement condition rotational speed: 2,000 rpm
Maximum particle size: 2.0 μm
Minimum particle size: 0.1 μm
Particle size interval: 0.1 μm
Dispersion medium viscosity: 0.59 mPa · s
Dispersion medium density: 0.87 g / cm ³
Particle density: True specific gravity value measured using a dry automatic bulk density meter Accupic 1330 (manufactured by Shimadzu Corporation) The content of the particles in the protective layer is not particularly limited and may be appropriately selected depending on the purpose. However, it is preferably 50 parts by mass to 500 parts by mass and more preferably 100 parts by mass to 300 parts by mass with respect to 100 parts by mass of the resin.

  When the content is less than 50 parts by mass, the effect of preventing the protective layer from being scraped or peeled off may be reduced. When the content exceeds 500 parts by mass, the proportion of the resin that appears on the carrier surface is relatively high. The toner tends to be spent on the carrier surface. On the other hand, when the content is within the preferable range, it becomes possible to suppress the protective layer from being scraped or peeled off when used for a long time in a developing device.

  The ratio (D / h) of the volume average particle diameter D (μm) of the particles to the average thickness h (μm) of the protective layer is not particularly limited and may be appropriately selected depending on the purpose. 0.01 to 1.00 is preferable, and 0.10 to 1.00 is more preferable.

  When the D / h is less than 0.01, the unevenness caused by the particles is hardly seen, the surface of the protective layer becomes flat, the charging performance is deteriorated due to adhesion of the toner, and the image quality is improved. If it exceeds 1.00, when running in a low image area, the convex portion due to the particles of the protective layer may be scraped, resulting in a decrease in resistance and the image quality. There are things to do. On the other hand, when the D / h is within the more preferable range, it is advantageous in that durability is good and carrier adhesion can be suppressed.

  There is no restriction | limiting in particular as content in the protective layer of the said particle | grain, Although it can select suitably according to the objective, 10 mass%-90 mass% are preferable, 40 mass%-85 mass% are more preferable, 50 A mass% to 80 mass% is particularly preferred.

  When the content is less than 10% by mass, since the ratio of particles on the surface of the carrier is small, the effect of relaxing contact with a strong impact on the resin may be reduced, and when it exceeds 90% by mass, Since the ratio of the resin on the surface of the carrier is small, the charging performance may be lowered, and the ability of retaining particles by the resin may be insufficient.

  In addition, content of the said particle | grain is represented by a following formula.

Content of particles (% by mass) = {particles / (particles + total amount of resin solids)}
<Carrier manufacturing method>
There is no restriction | limiting in particular as a manufacturing method of the said carrier, Although it can select suitably according to the objective, The said resin and the said particle | grain are contained on the surface of the said core particle using a fluid bed type coating apparatus. A method of manufacturing by applying a protective layer forming solution is preferred. In addition, when apply | coating the said protective layer formation solution, you may advance condensation of the resin contained in the said protective layer, and after apply | coating the said protective layer formation solution, condensation of the resin contained in the said protective layer You may proceed. There is no restriction | limiting in particular as the condensation method of the said resin, According to the objective, it can select suitably, For example, the method of giving a heat | fever, light, etc. to the said protective layer formation solution, etc. are mentioned. .

<Volume specific resistance value of carrier>
The volume resistivity of the carrier, it is preferably not more than 1 × 10 ⁹ Ω · cm or more 1 × ^{10 17} Ω · cm volume resistivity, 1 × 10 ⁹ Ω · cm or more 1 × ^{10 12} Ω · cm or less Is more preferable. When the volume specific resistance is less than 1 × 10 ⁹ Ω · cm, the amount of toner adhering to the developer carrying member during non-image (for example, the amount of toner adhering to the developing sleeve due to the bias toward the developing sleeve) May increase, and image uniformity may not be obtained. If the volume resistivity exceeds 1 × 10 ¹⁷ Ω · cm, the toner adhering to the developer carrier during printing is consumed, and image uniformity may not be obtained. In addition, when it falls below the measurable lower limit of the high resist meter, the volume specific resistance value is not substantially obtained, and it will be treated as a breakdown.

  The volume specific resistance value can be measured by the following method.

  First, an electrode having a distance between electrodes of 2 mm and a surface area of 2 cm × 4 cm, a cell made of a fluororesin container containing the electrode is filled with a carrier, and a tapping machine PTM-1 type (manufactured by Sankyo Piotech Co., Ltd.) is used. Tapping operation is performed for 1 minute at a tapping speed of 30 times / min. Next, a DC voltage of 1,000 V is applied between the two electrodes, the DC resistance is measured by a high resistance meter 4329A (4329A + LJK5HVLVWDQFH 0HWHU; manufactured by Yokogawa Hewlett-Packard Co., Ltd.), electric resistivity RΩ · cm is obtained, and LogR is calculated. .

<Weight average particle diameter Dw of carrier>
The weight average particle diameter Dw of the carrier refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction / scattering method.

  There is no restriction | limiting in particular as the weight average particle diameter Dw of the said carrier, Although it can select suitably according to the objective, It is preferable that it is 20 micrometers-65 micrometers. When the weight average particle diameter is within the above range, the effect of improving carrier adhesion, image quality, etc. is remarkable. This is because when the weight average particle size is less than 20 μm, the uniformity of the particles is lowered, and fine powders of less than 20 μm are liable to adhere to a solid carrier due to centrifugal force during development or injection of development bias, and are sufficient on the machine side. Problems such as carrier adhesion may occur due to the inability to establish a skill to use. On the other hand, if it exceeds 65 μm, the reproducibility of image details is poor and a fine image may not be obtained.

  The weight average particle size Dw is calculated based on the particle size distribution (relationship between the number frequency and the particle size) of particles measured on a number basis.

  The weight average particle diameter Dw in this case is represented by the following formula (1).

Dw = {1 / Σ (nD2)} × {Σ (nD4)} (1)
(In formula (1), D represents the representative particle size (μm) of particles present in each channel, and n represents the total number of particles present in each channel)
The channel indicates a length for dividing the particle size range in the particle size distribution diagram into measurement width units, and adopts an equal length (particle size distribution width) of 2 μm.

  In addition, as the representative particle size of the particles present in each channel, the lower limit value of the particle size stored in each channel is adopted.

  The number average particle diameter Dp is calculated based on the particle size distribution of the particles measured on the basis of the number.

  The number average particle diameter Dp in this case is expressed by the following formula (2).

Dp = (1 / N) × (ΣnD) (2)
In the above formula (2), N represents the total number of particles measured, n represents the total number of particles present in each channel, and D represents the lower limit value of the particle size present in each channel (2 μm). .

  As a particle size analyzer for measuring the particle size distribution, a Microtrac particle size analyzer (model HRA9320-X100, manufactured by Honeywell) is used. The measurement conditions are as follows.

-Measurement conditions-
[1] Particle size range: 100 nm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42
<Carrier magnetization>
The magnetization of the carrier (magnetic moment) is not particularly limited and may be appropriately selected depending on the purpose, in a magnetic field of ^{1kOe, 40Am 2 / kg~90Am 2 /} kg is preferred.

  For the measurement of the magnetization, for example, a highly sensitive vibration sample type magnetometer (VSM-P7-15, manufactured by Toei Kogyo Co., Ltd.) can be used. As a specific measurement method, about 0.15 g of a carrier is weighed, and the carrier is filled in a cell (see FIG. 8) having an inner diameter of 2.4 mm and a height of 8.5 mm, and 1,000 Elstet (Oe) Measure under a magnetic field of. The cell shown in FIG. 8 is a cell composed of a fluororesin container 2 containing electrodes 1a and 1b having a distance between electrodes of 0.2 cm and a surface area of 2.5 cm × 4 cm, and is filled with a carrier 3.

(Developer)
The developer includes a carrier and a toner.

  The toner has base particles and a non-spherical external additive, and further contains other components as necessary.

  The toner contains the non-spherical external additive to achieve high fluidity, and the external additive is buried even when a load is applied to the toner by stirring in the developing device. Suppressing and rolling is excellent in maintaining the toner retaining force of the carrier over time.

  Here, an example of rolling of the external additive will be described with reference to the drawings. FIG. 9A, FIG. 10A, and FIG. 11A are schematic views of a toner containing an external additive. The shape of the external additive 103 of the toner 101 shown in FIG. 9A is a sphere. The shape of the external additive 103 of the toner 101 shown in FIG. 10A is a non-spherical shape (spindle shape). The external additive 103 of the toner 101 shown in FIG. 11A is non-spherical coalesced particles.

  In the toner 101 shown in FIG. 9A, since the external additive 103 has a spherical shape, when a load is applied to the toner 101, the external additive 103 rolls on the surface of the base particle 102 in the direction of the arrow, As a result, the external additive 103 becomes non-uniform (see FIG. 9B).

  In the toner 101 shown in FIGS. 10A and 11A, since the external additive 103 has a non-spherical shape, the external additive 103 is difficult to roll even when a load is applied to the toner 101 (see FIGS. 10B and 10B). 11B).

  When the external additive is buried or rolled, the tie due to the interaction between the unevenness of the carrier and the unevenness of the toner obtained in FIG. It is difficult to obtain sufficient contact between the fine irregularities of the protective layer including the resin 112 and the particles 113 and the external additive (see the round broken line portion in FIG. 12).

  Although the toner adheres to the surface of the carrier, the toner may move from the surface of the carrier due to the contact with the photoconductor or the influence of the potential of the non-image area. When the toner moves, a counter charge may occur on the carrier and the carrier may adhere to the non-image area, and it is important to fix the toner on the surface of the carrier.

  Further, when the external additive is buried or rolled, the distance between the base particle and the developing sleeve is shortened (see FIG. 13), and the adhesion between the toner and the developing sleeve may be increased.

  On the other hand, if the embedding or rolling of the external additive is suppressed, the distance between the base particle and the developing sleeve can be maintained (see FIG. 14), and the non-electrostatic adhesion between the toner and the developing sleeve can be reduced. Can be kept low.

  In other words, the non-image portion is prevented by suppressing the embedding or rolling of the external additive in the toner, keeping the holding force (adhesion force) between the toner and the carrier large, and keeping the adhesion force with the developing sleeve low. In this case, when a bias is applied in the direction from the photoconductor to the developing sleeve, it is possible to suppress the toner from adhering to the developing sleeve and to further suppress the ghost phenomenon due to the image history.

  Furthermore, when the non-spherical external additive is coalesced particles, and the coalescence degree G of the coalesced particles is 1.5 to 4.0, the above effect becomes remarkable.

  Usually, when a small particle size toner is used in an electrophotographic image forming apparatus, the non-electrostatic adhesion force between the toner and the photosensitive member or between the toner and the intermediate transfer member is increased, so that the transfer efficiency is lowered. To do. In particular, when a small-diameter toner is used in a high-speed machine, non-electrostatic adhesion to the intermediate transfer member is increased by reducing the particle diameter of the toner, and the transfer nip portion, It is known that the time during which the toner is subjected to the transfer electric field in the nip portion of the secondary transfer is shortened, so that the transfer efficiency in the secondary transfer is significantly reduced.

  However, by using the toner containing the non-spherical external additive, the non-electrostatic adhesion force of the toner is reduced, and even when the transfer time is shortened as in a high-speed machine, the fixability is hindered. Sufficient transfer efficiency can be obtained. Furthermore, even when the mechanical stress with time is large as in a high-speed machine, the external additive does not roll into the recesses and the function of the external additive is not lost, and sufficient transfer efficiency is maintained over the long term. It is possible.

  There is no restriction | limiting in particular as said external additive, Although it can select suitably according to the objective, It is preferable to contain a non-spherical external additive.

  The non-spherical external additive is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a spindle-shaped external additive and coalesced particles.

-Fused particles-
The coalesced particles are non-spherical particles obtained by coalescing primary particles, that is, secondary particles in which a plurality of primary particles (reference numerals 1A to 1D) are coalesced (aggregated) as shown in FIG. Say. The “cohesive particles” may be referred to as “secondary particles”.

-Primary particles-
The primary particles are not particularly limited and can be appropriately selected depending on the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, Tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Inorganic particles, organic particles, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, silica is preferable because it can prevent the external additive from being buried and detached from the base particles.

  The volume average particle diameter of the secondary particles, that is, the volume average particle diameter of the coalesced particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 15 nm to 400 nm, preferably 50 nm to 300 nm. More preferred. When the volume average particle diameter is less than 15 nm, the external additive is easily embedded, and sufficient durability can be maintained. Cleaning performance may be insufficient. Since the adhesion of the external additive is remarkably inferior and the external additive is easily detached from the toner, the transferability may not be maintained.

  The volume average particle diameter of the secondary particles is measured by field emission scanning of a sample obtained by dispersing the secondary particles in an appropriate solvent (such as THF) and then removing the solvent on the substrate to dry the sample. This is done by measuring the particle size of secondary particles in the field of view with an electron microscope (FE-SEM, acceleration voltage: 5 kV to 8 kV, observation magnification: 8,000 times to 10,000 times). The whole image is predicted from the outer frame of the bonded secondary particles, and the longest length of the whole image (the length of the arrow shown in FIG. 2) is measured (measured number of particles: 100 or more). .

-Manufacturing method of coalesced particles-
The method for producing the coalesced particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, a method of producing by the sol-gel method is preferable, and specifically, the primary particles and the treatment agent are mixed. Or the method of manufacturing by making it chemically combine by baking and making it secondary-aggregate and making it a secondary particle (cohesion particle) is preferable. When synthesizing by the sol-gel method, coalescent particles may be prepared by a one-step reaction in the presence of the treatment agent. Although an example of a manufacture example is shown below, it is not restricted to this.

-Treatment agent-
There is no restriction | limiting in particular as said processing agent, According to the objective, it can select suitably, For example, a silane processing agent, an epoxy processing agent, etc. are mentioned. These may be used alone or in combination of two or more. When silica is used as the primary particles, the Si—O—Si bond formed by the silane-based treatment agent is more heated than the Si—O—C bond formed by the epoxy-based treatment agent. From the viewpoint of stability, a silane-based treatment agent is preferable. Moreover, you may use processing adjuvants (water, 1 mass% acetic acid aqueous solution, etc.) as needed.

-Silane treatment agent-
There is no restriction | limiting in particular as said silane type processing agent, According to the objective, it can select suitably, For example, alkoxysilanes (tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxy) Silane, dimethyldiethoxysilane, methyldimethoxysilane, methyldiethoxysilane, diphenyldimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, etc.); silane coupling agents (γ-aminopropyltolethoxysilane, γ-glycidoxy) Propyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, methylvinyldi Methoxysilane, etc.); vinyltrichlorosilane, dimethyldichlorosilane, methylvinyldichlorosilane, methylphenyldichlorosilane, phenyltrichlorosilane, N, N′-bis (trimethylsilyl) urea, N, O-bis (trimethylsilyl) acetamide, dimethyltrimethylsilyl Examples thereof include a mixture of amine, hexamethyldisilazane and cyclic silazane.

  As shown below, the silane-based treatment agent causes the primary particles (for example, silica primary particles) to form chemical bonds to form secondary aggregation.

  When the silica primary particles are treated using the alkoxysilanes, the silane coupling agent, or the like as the silane treatment agent, as shown in the following formula (A), a silanol group bonded to the silica primary particles And an alkoxy group bonded to the silane-based treatment agent react to form a new Si—O—Si bond by dealcoholization and secondary aggregation.

  When the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, the chloro group of the chlorosilanes and the silanol group bonded to the silica primary particles are dehydrochlorinated to form new Si. The silanol group bonded to —O—Si forms a new Si—O—Si bond by the dehydration reaction, and secondarily aggregates. Further, when the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, when water coexists in the system, the chlorosilanes are first hydrolyzed into water to generate silanol groups, The silanol groups bonded to the silanol groups and the silica primary particles form a new Si—O—Si bond by the dehydration reaction, and are secondarily aggregated.

  When the silica primary particles are treated with silazanes as the silane treatment agent, a new Si-O-Si bond is formed by deammoniation of the silanol groups bonded to the amino groups and the silica primary particles. Secondary aggregation.

However, in said formula (A), R shows an alkyl group.

-Epoxy treatment agent-
There is no restriction | limiting in particular as said epoxy type processing agent, According to the objective, it can select suitably, For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, Examples thereof include bisphenol A novolac type epoxy resin, biphenol type epoxy resin, glycidylamine type epoxy resin, and alicyclic epoxy resin.

  As shown in the following formula (B), the epoxy treating agent chemically bonds the silica primary particles to form secondary aggregation. When the silica primary particles are treated using the epoxy-based treatment agent, silanol groups bonded to the silica primary particles add an epoxy group oxygen atom and a carbon atom bonded to the epoxy group of the epoxy-based treatment agent. Thus, a new Si—O—C bond is formed and secondary aggregation occurs.

There is no restriction | limiting in particular as mixing mass ratio (primary particle: treatment agent) of the said processing agent and the said primary particle, Although it can select suitably according to the objective, 100: 0.01-100: 50 is preferable. . In addition, it exists in the tendency for a coalescence degree to become high, so that there is much quantity of the said processing agent.

  There is no restriction | limiting in particular as a mixing method of the said processing agent and the said primary particle, According to the objective, it can select suitably, For example, the method of mixing with a well-known mixer (spray dryer etc.) etc. are mentioned. When mixing, the primary particles may be prepared and then mixed with the treatment agent, or when the primary particles are prepared, the treatment agent is allowed to coexist and prepared in a one-step reaction. May be.

According to this production method, D ₅₀ / D ₁₀ needs to be 1.2 or less in the particle size distribution of the average secondary particle diameter D, and particularly preferably 1.15 or less. Here, D ₅₀ is the average particle size of 50% th measured from smaller particles of secondary particle diameter observed by the FE-SEM, D ₁₀ represents the average particle size of 10% th measured from smaller particles ing. D ₅₀ / D ₁₀ indicates the ratio of small particles having a secondary particle size and center particle, and an increase in this value indicates that there are many particles having a small secondary particle size. That is, either the particle A existing in the state of primary particles in which coalescence has not progressed, or the coalescence has progressed, but the primary particles themselves have many particles B having a small particle diameter, or both. It means that. Such particles A or B do not have sufficient functions. The particle A cannot function as an irregular additive and is inferior in embedment resistance, so there is a concern that an abnormal image may be generated. On the other hand, B cannot function as a spacer effect, and is buried due to external stress. There is a high possibility that it cannot be suppressed. It is desirable to reduce these particles, ie, D ₁₀ is large. When D ₅₀ / D ₁₀ exceeds 1.2, the amount of the above-described particles A and B is too large, so that it is difficult to perform the function as a deformed additive characterized for suppressing burying.

  The coalesced particles are not particularly limited as long as the following formula (1) is satisfied, and can be appropriately selected according to the purpose.

  Since the coalesced particles maintain the cohesive force (cohesive force) between the primary particles even under a constant stirring condition, the durability of the toner is enhanced.

(Nx / 1000) × 100 ≦ 30 (1)
However, in the formula (1), Nx represents the number of unattached primary particles in 1,000 particles of the external additive. The number of unattached primary particles in 1,000 particles was 67 Hz for 10 minutes with respect to 0.5 g of the external additive and 49.5 g of the carrier placed in a 50 mL bottle. After stirring using a rocking mill (manufactured by Seiwa Giken Co., Ltd.), it is selected by observing with a scanning electron microscope.

  When the coalescing force of the coalesced particles is strong (as shown in FIG. 16C, primary particles that are not coalesced in 1,000 of the coalesced particles (for example, particles shown in a black frame in FIG. 16C)) If the ratio of the external additive is 30% or less), the external additive in the toner is less likely to crack or disintegrate due to the load of the developing device (cracking or disintegrating particles), and burying or rolling of the external additive is suppressed. Thus, the occurrence of abnormal images such as ghosts over time can be suppressed.

  In the formula (1), the non-fused primary particles refer to particles that are present alone as the primary particles, and after stirring the coalesced particles under the stirring conditions using the paint conditioner. Particles that have cracked or collapsed, for example, as shown by reference numeral 2 in FIG. 16B, FIG. 16C, and FIG. 16D, the primary particles are not coalesced and the particles exist alone. .

  In the formula (1), the shape of the non-attached primary particles is not particularly limited and can be appropriately selected according to the purpose. For example, as shown by reference numeral 2 in FIG. Often exists in state.

  In the formula (1), the method for confirming the presence of the unattached primary particles is not particularly limited and may be appropriately selected depending on the intended purpose. The method of confirming that the particles are present alone is preferable.

  There is no restriction | limiting in particular as a measuring method of the volume average particle diameter of the said primary particle | grains which are not coalesced, Although it can select suitably according to the objective, a scanning electron microscope (FE-SEM, acceleration voltage: 5 kV-8 kV). , Observation magnification: 8,000 times to 10,000 times), by measuring the average value of the particle diameters of unattached primary particles in the field of view (measured number of particles: 100 or more).

  In the formula (1), as the measurement of the unattached primary particles occupying the 1,000 particles, after stirring, the particles are observed with a scanning electron microscope, and the symbol 2 in FIG. Like the particles shown in the black frame of L, the particles present alone are measured as one unattached primary particle.

  In the formula (1), when measuring the number of cracked or disintegrated particles in 1,000 particles, coalescing particles formed by coalescing a plurality of particles were confirmed by the scanning electron microscope. In this case, the coalesced particles are measured as one particle.

  In the formula (1), the carrier is not particularly limited and may be appropriately selected depending on the intended purpose, but a protective layer forming solution of an acrylic resin and a silicone resin containing alumina particles is applied to the surface of the sintered ferrite powder. It is preferable to use coated ferrite powder obtained by drying.

  In said Formula (1), there is no restriction | limiting in particular as said 50 mL bottle, According to the objective, it can select suitably, For example, the commercially available glass bottle (made by Nidec Rika Glass Co., Ltd.) etc. are mentioned.

-Characteristics of coalesced particles-
The degree of coalescence of the coalesced particles (volume average particle diameter of secondary particles / volume average particle diameter of primary particles) is not particularly limited and may be appropriately selected depending on the intended purpose. 4.0 is preferred. When the degree of coalescence is less than 1.5, the external additive tends to roll into the recesses on the surface of the base particles and may not be excellent in transferability. Since the additive is easily peeled off, the carrier may be contaminated or the photoconductor may be damaged, which may cause image defects over time.

  The method for confirming that the primary particles of the coalesced particles are coalesced is not particularly limited and can be appropriately selected according to the purpose, but is observed with a scanning electron microscope (SEM). Thus, a method of confirming that the primary particles are coalesced is preferable.

  By using the coalesced particles, high fluidity of the toner is realized, and the embedding and rolling of the external additive are suppressed even when a load is applied to the toner such as stirring in the developing device. Thus, it is possible to maintain a high transfer rate over time.

  There is no restriction | limiting in particular as content of the said external additive, Although it can select suitably according to the objective, 0.1 mass part-5.0 mass parts are preferable with respect to 100 mass parts of base particles.

-Dry method-
There is no restriction | limiting in particular as said dry method, According to the objective, it can select suitably, For example, it can carry out using an apparatus as shown in FIG.

  The apparatus shown in FIG. 17 includes an evaporator 501 for vaporizing and supplying a raw material silicon compound, a supply pipe 502 for supplying a raw material silicon compound gas, a supply pipe 503 for supplying a combustible gas, and a support. A supply pipe 504 for supplying a flammable gas, a burner 505 connected to these supply pipes 502, 503, and 504, a reactor 506 (performing a flame hydrolysis reaction), and a cooling connected to the downstream side of the reactor 506 Tubes 507A, 507B, and 507C, a recovery device 508 that recovers the manufactured silica powder, an exhaust gas treatment device 509A installed downstream of the recovery device 508, and an exhaust fan 509B.

  For example, the supply pipe 504 is opened to supply oxygen gas to the burner, the ignition burner is ignited, then the supply pipe 503 is opened to supply hydrogen gas to the burner to form a flame, and silicon tetrachloride is evaporated to this. Gasified in a vessel 501 and supplied to cause a flame hydrolysis reaction, and the generated silica powder is recovered by the bag filter of the recovery device 508. The exhaust gas after the powder recovery is processed by the exhaust gas processing device 509A and exhausted through the exhaust fan 509B.

  There is no restriction | limiting in particular as content of the said non-spherical external additive in the said external additive, Although it can select suitably according to the objective, 10 mass%-90 mass% are preferable, 25 mass%-60 % By mass is more preferable, and 35% by mass to 55% by mass is particularly preferable.

  There is no restriction | limiting in particular as content of the said external additive in the said toner, Although it can select suitably according to the objective, 0.5 mass part-8.0 mass parts with respect to 100 mass parts of base particles. Is preferable, 2.0 parts by mass to 7.0 parts by mass is more preferable, and 3.5 parts by mass to 5.5 parts by mass is particularly preferable.

  The binder resin used for the toner is not particularly limited, and preferably contains at least two kinds of resins. Polyester resin, silicone resin, styrene / acryl resin, styrene resin, acrylic resin, epoxy resin, diene resin Known binder resins such as phenol resins, terpene resins, coumarin resins, amideimide resins, butyral resins, urethane resins, and ethylene / vinyl acetate resins can be used.

Among them, the resin phase for toner is preferably a polyester resin that has sufficient flexibility even when the molecular weight is lowered, in that it can sharply melt during fixing and smooth the image surface. Other resins may be used in combination. Polyester resin is a general formula A- (OH) m (1)
[Wherein, A represents an alkyl group having 1 to 20 carbon atoms, an alkylene group, or an aromatic group or heterocyclic aromatic group which may have a substituent. m represents an integer of 2 to 4. ]
And one or more polyols represented by the general formula B- (COOH) n (2)
[Wherein, B represents an alkyl group having 1 to 20 carbon atoms, an alkylene group, or an aromatic group or heterocyclic aromatic group which may have a substituent. n represents an integer of 2 to 4. ]
1 type, or 2 or more types of polycarboxylic acid represented by these are polyesterified.

Specific polyols represented by the general formula (1) include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2, 3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methyl Propanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide addition Products, hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, and the like.

Specific polycarboxylic acids represented by the general formula (2) include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, and sebacic acid. Azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, Isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5 -Hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxyprop 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, emporic trimer acid, cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, Examples include butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, and ethylene glycol bis (trimellitic acid).

(Active hydrogen group-containing compound)
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when a polymer capable of reacting with the active hydrogen group-containing compound undergoes an extension reaction, a crosslinking reaction, or the like in an aqueous medium. The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. For example, a polymer that can react with the active hydrogen group-containing compound contains an isocyanate group. In the case of the polyester prepolymer (A), the amines (B) are preferable because they can be increased in molecular weight by a reaction such as an elongation reaction and a crosslinking reaction with the isocyanate group-containing polyester prepolymer (A).

  The active hydrogen group is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. Examples thereof include a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), amino group, carboxyl group, mercapto group. , Etc. can be used. These may be used individually by 1 type and may use 2 or more types together. Among these, alcoholic hydroxyl groups are particularly preferable.

  There is no restriction | limiting in particular as amines (B), According to the objective, it can select suitably, For example, diamine (B1), trivalent or more polyamine (B2), amino alcohol (B3), amino mercaptan (B4) ), Amino acid (B5), amino acid block of B1 to B5 (B6), and the like can be used. These may be used individually by 1 type and may use 2 or more types together. Among these, diamine (B1), a mixture of diamine (B1) and a small amount of a trivalent or higher polyamine (B2) are particularly preferable.

  Examples of the diamine (B1) include aromatic diamines, alicyclic diamines, aliphatic diamines, and the like. Examples of the aromatic diamine include phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, and the like. Examples of the alicyclic diamine include 4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, and isophoronediamine. Examples of the aliphatic diamine include ethylene diamine, tetramethylene diamine, and hexamethylene diamine.

  Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan, aminopropyl mercaptan, and the like. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.

  Examples of the blocked B1-B5 amino group (B6) include, for example, ketimine compounds, oxazolidone compounds, and the like obtained from any of B1 to B5 amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) Is mentioned.

  A reaction terminator is used to stop the elongation reaction, crosslinking reaction, etc. between the active hydrogen group-containing compound and the polymer capable of reacting with the active hydrogen group-containing compound. Use of a reaction terminator is preferable in that the molecular weight and the like of the adhesive substrate can be controlled within a desired range. As the reaction terminator, monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), or those obtained by blocking them (ketimine compounds) can be used.

  As a mixing ratio of the amines (B) and the isocyanate group-containing polyester prepolymer (A), an isocyanate group [NCO] in the isocyanate group-containing prepolymer (A) and an amino group in the amines (B) [ The mixing equivalent ratio of NHx] ([NCO] / [NHx]) is preferably 1/3 to 3/1, more preferably 1/2 to 2/1, and more preferably 1 / 1.5 to Particularly preferred is 1.5 / 1. This is because if the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may decrease. If it exceeds 3/1, the molecular weight of the urea-modified polyester resin is low. This is because the hot offset resistance may deteriorate.

(Polymer capable of reacting with active hydrogen group-containing compound)
The polymer that can react with the active hydrogen group-containing compound (hereinafter referred to as “prepolymer”) is not particularly limited as long as it has at least a site that can react with the active hydrogen group-containing compound. For example, a polyol resin, a polyacrylic resin, a polyester resin, an epoxy resin, a derivative resin thereof, or the like can be used. Among these, a polyester resin is particularly preferable in terms of high fluidity and transparency during melting. In addition, these may be used individually by 1 type and may use 2 or more types together.

  The site capable of reacting with the active hydrogen group-containing compound in the prepolymer is not particularly limited and may be appropriately selected from known substituents. For example, an isocyanate group, an epoxy group, a carboxylic acid, an acid chloride Group, and the like. These may be contained singly or in combination of two or more. Among these, an isocyanate group is particularly preferable. Among prepolymers, it is easy to adjust the molecular weight of the polymer component, ensuring oil-free low-temperature fixing characteristics for dry toners, especially good release and fixing properties even without a release oil coating mechanism for the heating medium for fixing. In view of the capability, a urea bond-forming group-containing polyester resin (RMPE) is particularly preferable.

  As a urea bond production | generation group, an isocyanate group etc. are mentioned, for example. When the urea bond generating group in the urea bond generating group-containing polyester resin (RMPE) is the isocyanate group, the polyester resin (RMPE) is particularly preferably an isocyanate group-containing polyester prepolymer (A). The isocyanate group-containing polyester prepolymer (A) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is a polycondensate of a polyol (PO) and a polycarboxylic acid (PC), and Examples include those obtained by reacting an active hydrogen group-containing polyester resin with polyisocyanate (PIC). There is no restriction | limiting in particular as a polyol (PO), According to the objective, it can select suitably, For example, diol (DIO), trihydric or more polyol (TO), diol (DIO), and trihydric or more polyol ( TO) and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, diol (DIO) alone or a mixture of diol (DIO) and a small amount of a trivalent or higher polyol (TO) is preferable. Examples of the diol (DIO) include alkylene glycol, alkylene ether glycol, alicyclic diol, alkylene oxide adduct of alicyclic diol, bisphenol, alkylene oxide adduct of bisphenol, and the like.

  As the alkylene glycol, those having 2 to 12 carbon atoms are preferable, and examples thereof include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. It is done. Examples of the alkylene ether glycol include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol. Examples of the alicyclic diol include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A. Examples of the alkylene oxide adduct of alicyclic diol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the alicyclic diol. Examples of bisphenols include bisphenol A, bisphenol F, and bisphenol S. Examples of the alkylene oxide adduct of bisphenols include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, and butylene oxide to bisphenols. Among these, alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols and the like are preferable, and alkylene oxide adducts of bisphenols, alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. Mixtures are particularly preferred.

  The trivalent or higher polyol (TO) is preferably 3 to 8 or higher, for example, a trihydric or higher polyhydric aliphatic alcohol, a trihydric or higher polyphenol, an alkylene of a trihydric or higher polyphenol. And oxide adducts. Examples of the trivalent or higher polyhydric aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, and the like. Examples of the trihydric or higher polyphenols include trisphenol bodies (such as Trisphenol PA manufactured by Honshu Chemical Industry Co., Ltd.), phenol novolacs, cresol novolacs, and the like. Examples of the alkylene oxide adduct of trihydric or higher polyphenols include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide to trihydric or higher polyphenols.

  The mixing mass ratio (DIO: TO) of the diol (DIO) and the trihydric or higher polyol (TO) in the mixture of the diol (DIO) and the trihydric or higher polyol (TO) is 100: 0.01 to 10 Is preferable, and 100: 0.01-1 is more preferable.

  There is no restriction | limiting in particular as polycarboxylic acid (PC), Although it can select suitably according to the objective, For example, dicarboxylic acid (DIC), trivalent or more polycarboxylic acid (TC), dicarboxylic acid (DIC) And a mixture of trivalent or higher valent polycarboxylic acids. These may be used individually by 1 type and may use 2 or more types together. Among these, dicarboxylic acid (DIC) alone or a mixture of dicarboxylic acid (DIC) and a small amount of trivalent or higher polycarboxylic acid (TC) is preferable.

  Examples of the dicarboxylic acid (DIC) include alkylene dicarboxylic acid, alkenylene dicarboxylic acid, aromatic dicarboxylic acid, and the like. Examples of the alkylene dicarboxylic acid include succinic acid, adipic acid, and sebacic acid. Moreover, as alkenylene dicarboxylic acid, a C4-C20 thing is preferable, For example, a maleic acid, a fumaric acid, etc. are mentioned. Moreover, as aromatic dicarboxylic acid, a C8-C20 thing is preferable, for example, a phthalic acid, isophthalic acid, a terephthalic acid, naphthalene dicarboxylic acid etc. are mentioned. Among these, alkenylene dicarboxylic acid having 4 to 20 carbon atoms and aromatic dicarboxylic acid having 8 to 20 carbon atoms are preferable.

  The trivalent or higher polycarboxylic acid (TC) is preferably 3 to 8 or higher, and examples thereof include aromatic polycarboxylic acids. Moreover, as an aromatic polycarboxylic acid, a C9-C20 thing is preferable, for example, trimellitic acid, pyromellitic acid, etc. are mentioned.

  The polycarboxylic acid (PC) is any one selected from dicarboxylic acid (DIC), trivalent or higher polycarboxylic acid (TC), and a mixture of dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid. These acid anhydrides or lower alkyl ester compounds can also be used. Examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like.

  As a mixing mass ratio (DIC: TC) of dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid (TC) in a mixture of dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid (TC), There is no restriction | limiting, According to the objective, it can select suitably, For example, 100: 0.01-10 are preferable and 100: 0.01-1 are more preferable.

  The mixing ratio for the polycondensation reaction between the polyol (PO) and the polycarboxylic acid (PC) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the hydroxyl group in the polyol (PO) [ OH] and the equivalent ratio ([OH] / [COOH]) of the carboxyl group [COOH] in the polycarboxylic acid (PC) are usually preferably 2/1 to 1/1, and 1.5 / The ratio is more preferably 1-1 / 1, and particularly preferably 1.3 / 1-1.02 / 1.

  There is no restriction | limiting in particular as content in the isocyanate group containing polyester prepolymer (A) of a polyol (PO), Although it can select suitably according to the objective, 0.5-40 mass% is preferable, for example. -30 mass% is more preferable, and 2-20 mass% is especially preferable. This is because if the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both the heat-resistant storage stability and the low-temperature fixability of the toner. This is because the low temperature fixability may be deteriorated if the temperature exceeds.

  There is no restriction | limiting in particular as polyisocyanate (PIC), Although it can select suitably according to the objective, For example, aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic diisocyanate, araliphatic diisocyanate, isocyanurates And those blocked with phenol derivatives, oximes, caprolactams, and the like.

  Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetra And methyl hexane diisocyanate. Examples of the alicyclic polyisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate. Examples of the aromatic diisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 3 -Methyldiphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate and the like. Examples of the araliphatic diisocyanate include α, α, α ′, α′-tetramethylxylylene diisocyanate. Examples of isocyanurates include tris (isocyanatoalkyl) isocyanurate and triisocyanatocycloalkyl-isocyanurate. These may be used alone or in combination of two or more.

  As a mixing ratio when the polyisocyanate (PIC) is reacted with an active hydrogen group-containing polyester resin (for example, a hydroxyl group-containing polyester resin), an isocyanate group [NCO] in the polyisocyanate (PIC) and a hydroxyl group in the hydroxyl group-containing polyester resin [ The mixing equivalent ratio with [OH] ([NCO] / [OH]) is usually preferably 5/1 to 1/1, more preferably 4/1 to 1.2 / 1. It is particularly preferably 1 to 1.5 / 1. This is because if the isocyanate group [NCO] exceeds 5, low-temperature fixability may deteriorate, and if it is less than 1, offset resistance may deteriorate.

  There is no restriction | limiting in particular as content in the isocyanate group containing polyester prepolymer (A) of polyisocyanate (PIC), Although it can select suitably according to the objective, For example, 0.5-40 mass% is preferable, 1-30 mass% is more preferable, and 2-20 mass% is further more preferable. This is because, when the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability, and exceeds 40% by mass. This is because the low-temperature fixability deteriorates.

  As an average number of the isocyanate groups contained per molecule of the isocyanate group-containing polyester prepolymer (A), 1 or more is preferable, 1.2 to 5 is more preferable, and 1.5 to 4 is more preferable. This is because if the average number of isocyanate groups is less than 1, the molecular weight of the polyester resin (RMPE) modified with urea bond-forming groups is lowered, and the hot offset resistance is deteriorated.

  The weight average molecular weight (Mw) of the polymer capable of reacting with the active hydrogen group-containing compound is preferably 3,000 to 40,000 in terms of molecular weight distribution by GPC (gel permeation chromatography) soluble in tetrahydrofuran (THF). 4,000 to 30,000 are more preferable. This is because when the weight average molecular weight (Mw) is less than 3,000, the heat resistant storage stability may be deteriorated, and when it exceeds 40,000, the low temperature fixability may be deteriorated.

The molecular weight distribution can be measured by gel permeation chromatography (GPC), for example, as follows. That is, first, the column was stabilized in a 40 ° C. heat chamber, and at this temperature, tetrahydrofuran (THF) was flowed as a column solvent at a flow rate of 1 ml / min to adjust the sample concentration to 0.05 to 0.6% by mass. Measurement is performed by injecting 50 to 200 μl of a tetrahydrofuran sample solution of the resin. In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared by several monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical Co. Or Toyo Soda Kogyo Co., Ltd. having a molecular weight of ^{6 × 10 2, 2.1 × 10} 2, 4 × 10 2, 1.75 × 10 4, 1.1 × 10 5, 3.9 × 10 5, 8.6 It is preferable to use those of × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ and use at least about 10 standard polystyrene samples. An RI (refractive index) detector can be used as the detector.

(Stabilizer)
Various stabilizers for emulsifying and dispersing the oily phase in which the toner composition is dispersed are used in the liquid containing water. Such dispersants include surfactants, inorganic particle dispersants, polymer particle dispersants and the like.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, bis (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine It is below.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (Daikin Kogyo Co., Ltd.), MegaFuck F-110, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F-150 (manufactured by Neos).

  Examples of cationic surfactants include aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, and benzaza. Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Megafac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos).

  In addition, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant that is hardly soluble in water.

  Moreover, the same effect as the inorganic dispersant was confirmed for the particle polymer. For example, MMA polymer particles 1 μm and 3 μm, styrene particles 0.5 μm and 2 μm, styrene-acrylonitrile particle polymer 1 μm, (PB-200H (manufactured by Kao) SGP (Soken), Technopolymer SB (Sekisui Plastics), SGP-3G (Soken) Micropearl (Sekisui Fine Chemical)).

  In addition, as a dispersant that can be used in combination with the above inorganic dispersant and particle polymer, the dispersed droplets may be stabilized by a polymeric protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as Pinyl acetate, pinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

(Other ingredients)
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a coloring agent, a mold release agent, a charge control agent, an inorganic particle, a fluid improvement agent, a cleaning property improvement agent, magnetic Materials, metal soaps, and the like.

(Coloring agent)
The colorant for toner is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, 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, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow ( G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Zhu, Cadmium Red , Cadmium Mercury Red, Antimon Zhu, Permanent Red 4 , Para Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B , Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, 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, Thioindigo Maroo , Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green , Chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green gold, Acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon, etc. These may be used individually by 1 type and may use 2 or more types together.

  The content of the colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass. When the content of the colorant is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, poor pigment dispersion occurs in the toner, resulting in a reduction in the coloring power, and the toner. The electrical characteristics may be degraded.

  The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, polyester, styrene or a substituted polymer thereof, styrene copolymer, polymethyl methacrylate, polybutyl Methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic Examples thereof include hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffin waxes. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polymer of styrene or a substituted product thereof include polyester resin, polystyrene, poly p-chlorostyrene, polyvinyl toluene, and the like. Examples of the styrene copolymer include a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-methyl acrylate copolymer. Polymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate 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 N-acrylonitrile-indene copolymer, Styrene - maleic acid copolymer, styrene - maleic acid ester copolymer, and the like.

  The master batch can be produced by mixing or kneading a resin for a master batch and a colorant with a high shear force. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. This flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. For the mixing or kneading, for example, a high shear dispersion device such as a three-roll mill is preferably used. The colorant can be arbitrarily contained in both the first resin phase and the second resin phase by utilizing the difference in affinity for the two resins. It is well known that the colorant deteriorates the charging performance of the toner when present on the toner surface. Therefore, the charging performance (environmental stability, charge retention ability, charge amount, etc.) of the toner can be improved by selectively containing a colorant in the first resin phase present in the inner layer.

(Release agent)
There is no restriction | limiting in particular as a mold release agent, Although it can select suitably according to the objective, The low melting-point mold release agent whose melting | fusing point is 50-120 degreeC is preferable. The low melting point release agent, when dispersed with the resin, effectively acts as a release agent between the fixing roller and the toner interface, thereby preventing oilless (a release agent such as oil on the fixing roller). Even if it is not applied), the hot offset property is good.

  Preferable examples of the release agent include waxes and waxes. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, and rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cercin; paraffin and microcrystalline. And natural waxes such as petroleum waxes such as Petrolatum; In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax; synthetic waxes such as esters, ketones and ethers; Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons; poly-n-stearyl methacrylate and poly-n-lauryl which are low molecular weight crystalline polymer resins A homopolymer or copolymer of a polyacrylate such as methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.); a crystalline polymer having a long alkyl group in the side chain, or the like may be used. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as melting | fusing point of a mold release agent, Although it can select suitably according to the objective, 50-120 degreeC is preferable and 60-90 degreeC is more preferable. If the melting point is less than 50 ° C., the wax may adversely affect the heat-resistant storage stability, and if it exceeds 120 ° C., a cold offset may easily occur during fixing at a low temperature. The melt viscosity of the release agent is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point of the wax. When the melt viscosity is less than 5 cps, the releasability may be lowered, and when it exceeds 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained. There is no restriction | limiting in particular as content in the said toner of a mold release agent, Although it can select suitably according to the objective, 0-40 mass% is preferable and 3-30 mass% is more preferable. When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

  The release agent can be arbitrarily contained in both the first resin phase and the second resin phase by utilizing the difference in affinity for the two resins. By selectively including in the second resin phase present in the outer layer of the toner, the release of the release agent can occur sufficiently even in a short heating time during fixing, so that sufficient release properties can be obtained. Further, by selectively including the release agent in the first resin phase present in the inner layer, the spent of the release agent to other members such as a photoreceptor and a carrier can be suppressed. The arrangement of the release agent may be designed relatively freely, and an arbitrary arrangement can be taken according to each image forming process.

-Charge control agent-
The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, Alkoxy amine, quaternary ammonium salt (including fluorine-modified quaternary ammonium salt), alkylamide, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine activator, salicylic acid metal salt, salicylic acid derivative metal salt, copper Examples thereof include phthalocyanine, perylene, quinacridone, azo pigments, and other polymer compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt.

  Trade names of the charge control agents include, for example, Nigrosine dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, and oxynaphthoic acid metal complex E-82. , Salicylic acid metal complex E-84, phenol condensate E-89 (above, manufactured by Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.) Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, NX VP434 (above, Hoechst), LRA-901, LR -147 (above, manufactured by Nippon Carlit Co., Ltd.).

  The content of the charge control agent is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the binder resin. 0.2 mass part-5 mass parts are more preferable. When the content exceeds 10 parts by mass, the chargeability of the toner is too large, the effect of the main charge control agent is reduced, the electrostatic attraction force with the developing roller is increased, and the flowability of the developer is reduced. The image density may be reduced. The charge control agent may be melt-kneaded with a masterbatch and resin, and then dissolved and dispersed, or may be added when directly dissolving or dispersing in the organic solvent, and is fixed after the toner particles are formed on the toner surface. You may make it.

  The base particle contains the modified polyester resin, the unmodified polyester resin, and the colorant, and the base particle has a site capable of reacting with the active hydrogen group-containing compound that is a precursor of the modified polyester resin. The polymer having, the active hydrogen group-containing compound, the unmodified polyester resin, and the colorant are added to an organic solvent and emulsified or dispersed to obtain an emulsified or dispersed liquid, and then the emulsified or dispersed liquid is used. It is preferably obtained by subjecting an active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound to elongation or crosslinking reaction.

<Toner production method>
There is no restriction | limiting in particular as a manufacturing method of the said toner, According to the objective, it can select suitably, For example, the method of manufacturing by the pulverization method, the method of manufacturing by the polymerization method, etc. are mentioned. Among these, the method of producing by a polymerization method is preferable in that the toner can be reduced in particle size.

<Crushing method>
The pulverization method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of producing base particles by melting or kneading a toner material and pulverizing or classifying it. For the purpose of setting the average circularity of the toner to 0.97 to 1.0, the shape may be controlled by applying a mechanical impact force to the obtained toner base particles. In this case, examples of a method for applying the mechanical impact force include a method using a device such as a hybridizer or mechanofusion. Further, the toner is obtained by treating the base particles thus produced with an external additive.

<Polymerization method>
There is no restriction | limiting in particular as said polymerization method, According to the objective, it can select suitably, For example, suspension polymerization method, solution suspension polymerization method, emulsion polymerization aggregation method, etc. are mentioned. Among these, the emulsion polymerization aggregation method is preferable, and the dissolution suspension method is more preferable.

-Dissolution suspension method-
The dissolution suspension method is not particularly limited and may be appropriately selected depending on the intended purpose, but a method of production by aqueous granulation is preferable, an oil phase preparation step, an aqueous phase preparation step, an emulsification or dispersion step, The method of manufacturing by including a solvent removal process, a washing | cleaning thru | or drying process, and an external additive process process is more preferable.

  Specific examples of the dissolution suspension method are not particularly limited and may be appropriately selected depending on the intended purpose. However, a toner obtained by dissolving or dispersing at least the binder resin and the colorant in an organic solvent. A matrix particle obtained by adding a material dissolution or dispersion into an aqueous phase and emulsifying or dispersing to obtain an emulsion or dispersion, and then removing the organic solvent from the emulsion or dispersion, and an external additive And a method of producing a toner by mixing the toner.

  Among the dissolution suspension methods, an ester extension method is preferable. Specific examples of the ester extension method include at least the active hydrogen group-containing compound, a polymer having a site capable of reacting with the active hydrogen group-containing compound, A solution or dispersion of a toner material obtained by dissolving or dispersing the coloring resin and the colorant in an organic solvent is added to the aqueous phase and emulsified or dispersed to obtain an emulsion or dispersion, and then the emulsification. Or a matrix obtained by extending or cross-linking the active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound in a dispersion, and removing the organic solvent from the emulsion or dispersion. A method of producing a toner by mixing particles and an external additive is preferable.

-Oil phase preparation process-
The oil phase preparation step is a step of preparing an oil phase (solution or dispersion of toner material) by dissolving or dispersing a toner material containing at least the binder resin and the colorant in an organic solvent. Further, components other than the polymer having a polymer site capable of reacting with the active hydrogen group-containing compound in the toner material may be added and mixed in an aqueous medium in the preparation of an aqueous phase to be described later. When the dissolved or dispersed liquid of the material is added to the aqueous medium, it may be added to the aqueous medium together with the dissolved or dispersed liquid.

There is no restriction | limiting in particular as said organic solvent, Although it can select suitably according to the objective, The organic solvent whose boiling point is less than 150 degreeC is preferable at the point which solvent removal is easy. The organic solvent having a boiling point of less than 150 ° C. is not particularly limited and may be appropriately selected depending on the intended purpose. For example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1 1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is preferable. There is no restriction | limiting in particular as the usage-amount of the said organic solvent, Although it can select suitably according to the objective, 40 mass parts-300 mass parts are preferable with respect to 100 mass parts of said toner materials, and 60 mass parts-140 mass parts. Part is more preferable, and 80 parts by mass to 120 parts by mass is particularly preferable.

-Aqueous phase preparation process-
The aqueous phase preparation step is a step of preparing an aqueous phase (aqueous medium). There is no restriction | limiting in particular as said aqueous phase, According to the objective, it can select suitably, For example, water, the solvent miscible with water, these mixtures etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, water is preferable. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolv (registered trademark), etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like. Can be mentioned.

-Emulsification or dispersion process-
The emulsification or dispersion step is a step of obtaining an emulsification or dispersion by dispersing the oil phase in the aqueous phase. The toner material is not necessarily mixed when the particles are formed in the aqueous phase, and may be added after the particles are formed. For example, the particles containing no colorant may be formed. Thereafter, a coloring agent can be added by a known dyeing method. There is no restriction | limiting in particular as the usage-amount of the water phase with respect to 100 mass parts of said toner materials, Although it can select suitably according to the objective, 50 mass parts-2,000 mass parts are preferable, 100 mass parts-1, 000 parts by mass is more preferable. If the amount used is less than 50 parts by mass, the toner material may be poorly dispersed, and toner particles having a predetermined particle size may not be obtained. If it exceeds 2,000 parts by mass, it is not economical. There is. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  The dispersant used in the emulsification or dispersion step is not particularly limited and can be appropriately selected depending on the purpose. For example, an anionic surfactant, a cationic surfactant, a nonionic surfactant, Amphoteric surfactants, anionic surfactants having fluoroalkyl groups, cationic surfactants having fluoroalkyl groups, inorganic compounds (tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc.), particle polymers (MMA polymer particle 1 μm, MMA polymer particle 3 μm, styrene particle 0.5 μm, styrene particle 2 μm, styrene-acrylonitrile particle polymer 1 μm, etc.). Among these, a surfactant having a fluoroalkyl group is preferable in that the effect can be obtained in a very small amount.

There is no restriction | limiting in particular as content of the said dispersing agent, Although it can select suitably according to the objective, In the case of a resin particle dispersion liquid, 0.01 mass%-1 mass% are preferable, 0.02 mass% -0.5 mass% is more preferable, and 0.1 mass% -0.2 mass% is especially preferable. When the content is less than 0.01% by mass, aggregation may occur in a state where the pH of the emulsification or dispersion is not sufficiently basic. There is no restriction | limiting in particular as content of the said dispersing agent, Although it can select suitably according to the objective, In the case of a colorant dispersion or a mold release agent dispersion, 0.01 mass%-10 mass% are preferable. 0.1 mass% to 5 mass% is more preferable, and 0.5 mass% to 0.2 mass% is particularly preferable. When the content is less than 0.01% by mass, the stability between the particles is different at the time of agglomeration, so that the release of specific particles may occur. When the content exceeds 10% by mass, the particle size distribution of the particles becomes wide. In some cases, it may be difficult to control the particle size.

  As the trade name of the dispersant, Surflon S-111, S-112, S-113, S-121 (above, manufactured by Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129, FC-135 (above, manufactured by Sumitomo 3M), Unidyne DS-101, DS-102, DS-202 (above, manufactured by Daikin Industries), MegaFuck F-l0, F-l20, F-113, F-150 F-191, F-812, F-824, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 132, 306A, 501, 201, 204 (above, manufactured by Tochem Products Co., Ltd.), Footent F-100, F-300, F150 (above, manufactured by Neos), SGP, SGP-3G (above, Soken) Ltd.), manufactured by PB-200H (Kao Corporation), manufactured by Techno Polymer SB (manufactured by Sekisui Plastics Co., Ltd.), MICROPEARL (manufactured by Sekisui Fine Chemical Co., Ltd.).

When the dispersant is used, the dispersant may remain on the surface of the toner particles. However, it is preferable to remove it after the reaction in terms of the charged surface of the toner. Furthermore, it is preferable to use a solvent that can dissolve the modified polyester resin after the reaction of the polyester prepolymer, in that the particle size distribution becomes sharp and the viscosity of the toner material is lowered. The solvent is preferably a volatile solvent having a boiling point of less than 100 ° C. in terms of easy removal. For example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1 , 2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, methanol, and other water-miscible solvents. These may be used individually by 1 type and may use 2 or more types together. Among these, aromatic solvents such as toluene and xylene, and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable.

  The disperser used in the emulsification or dispersion step is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a low-speed shear disperser, a high-speed shear disperser, a friction disperser, a high pressure Examples thereof include a jet disperser and an ultrasonic disperser. Among these, a high-speed shearing disperser is preferable in that the particle diameter of the dispersion (oil droplets) can be controlled to 2 μm to 20 μm.

  When the high-speed shearing disperser is used, conditions such as the number of rotations, the dispersion time, and the dispersion temperature can be appropriately selected according to the purpose.

  There is no restriction | limiting in particular as said rotation speed, Although it can select suitably according to the objective, 1,000 rpm-30,000 rpm are preferable, and 5,000 rpm-20,000 rpm are more preferable.

  There is no restriction | limiting in particular as said dispersion | distribution time, Although it can select suitably according to the objective, In the case of a batch system, 0.1 minute-5 minutes are preferable.

  There is no restriction | limiting in particular as said dispersion | distribution temperature, Although it can select suitably according to the objective, 0 degreeC-150 degreeC is preferable under pressure, and 40 degreeC-98 degreeC is more preferable. In general, dispersion is easier when the dispersion temperature is higher.

-Solvent removal process-
The solvent removal step is a step of removing the organic solvent from the emulsion or dispersion (dispersion liquid such as an emulsion slurry). The method for removing the organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of gradually elevating the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, dispersion Examples thereof include a method in which the liquid is sprayed (spray dryer, belt dryer, rotary kiln, etc.) in a dry atmosphere (air, nitrogen, carbon dioxide, combustion gas, etc.) to remove the organic solvent in the oil droplets. By this method, the desired quality can be obtained in a short time. When the organic solvent is removed, base particles are formed.

-Cleaning or drying process-
The washing or drying step is a step of washing or drying the base particles. The base particles may be further classified. The classification may be performed by removing fine particle portions in a liquid by a cyclone, a decanter, centrifugation, or the like, or may be performed after drying. The obtained unnecessary fine particles or coarse particles can be used again for forming fine particles. At that time, fine particles or coarse particles may be in a wet state.

-External additive treatment process-
The external additive treatment step is a step of mixing and processing the base particles after drying and the external additive. The toner is obtained by mixing the base particles and the external additive. There is no restriction | limiting in particular as an apparatus used for the said mixing, Although it can select suitably according to the objective, Henschel mixer (made by Mitsui Mining Co., Ltd.) is preferable. A mechanical impact force may be applied in order to prevent the particles such as the external additive from being detached from the surface of the base particles. The method for applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. For example, a method for applying the impact force to the mixture using blades rotating at high speed, For example, a method may be used in which the mixture is charged and accelerated to cause the particles or particles to collide with an appropriate collision plate. The apparatus used in the above method is not particularly limited and can be appropriately selected depending on the purpose. For example, an ang mill (manufactured by Hosokawa Micron), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) and a pulverization air pressure are modified. And a hybridization system (manufactured by Nara Machinery Co., Ltd.), a kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

<Toner characteristics>
The ratio (Dv / Dn) between the volume average particle diameter (Dv) and the number average particle diameter (Dn) in the toner is not particularly limited and may be appropriately selected depending on the intended purpose. Is preferable, and 1.00-1.30 is more preferable. When the ratio (Dv / Dn) is less than 1.00, the toner is fused to the surface of the carrier during long-term agitation in the developing device, and the chargeability of the carrier and the cleaning property are likely to deteriorate. There is. When the ratio (Dv / Dn) exceeds 1.30, it is difficult to obtain a high-resolution and high-quality image, and the toner particle diameter varies when the toner in the developer is balanced. May increase.

  The average circularity of the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.95 to 0.98. If the average circularity is less than 0.95, the image uniformity during development deteriorates, and the toner transfer efficiency from the photosensitive member to the intermediate transfer member or from the intermediate transfer member to the recording material decreases, and uniform transfer is obtained. It may disappear. The production method by the dissolution suspension method is a method for producing a toner by emulsifying in an aqueous medium, and is particularly effective for reducing the particle size of a color toner and obtaining a shape having an average circularity in the above range. Is.

  The average circularity can be measured using, for example, a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 mL to 150 mL of water from which impure solids have been removed in advance is added, 0.1 mL to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 g to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the concentration and dispersion of the toner are adjusted to 3,000 / μL to 10,000 / μL. taking measurement.

<Method for producing developer>
The method for producing the developer is not particularly limited and may be appropriately selected depending on the purpose. For example, the method for producing the developer by mixing the carrier and the toner and stirring the mixture with a turbuler mixer. Etc.

(Replenishment developer)
The replenishment developer includes the carrier described above and the toner described above. Further, the replenishment developer can be applied to an image forming apparatus that forms an image while discharging excess developer in the developing device. Further, the developing device using the replenishment developer can obtain a stable image quality for a very long time. That is, the image forming apparatus using the replenishment developer replaces the deteriorated carrier in the development apparatus and the undegraded carrier in the replenishment developer, and keeps the charge amount stable for a long period of time. Therefore, a stable image can be obtained. This method is particularly effective when printing a large image area. Deterioration at the time of printing a large image area is mainly due to a decrease in carrier charging ability due to toner spent on the carrier. However, using this method, the amount of carrier replenishment increases when the image area is large. The frequency with which the changed carriers are replaced increases.

  There is no restriction | limiting in particular as content of the carrier in the said developer for replenishment, Although it can select suitably according to the objective, 3 to 30 mass% is preferable.

  The mixing ratio of the replenishment developer is preferably 2 to 50 parts by mass, preferably 5 to 12 parts by mass of the toner with respect to 1 part by mass of the carrier. When the amount of toner is less than 2 parts by mass, the amount of replenishment carrier is excessive, the carrier is excessively supplied, and the carrier concentration in the developing device becomes too high, so that the charge amount of the toner tends to increase. Further, when the charge amount of the toner increases, the developing ability decreases and the image density decreases. On the other hand, if the amount exceeds 50 parts by mass, the carrier ratio in the replenishment developer decreases, so that the replacement of carriers in the image forming apparatus decreases, and the effect on carrier deterioration cannot be expected.

(Developer)
The developing device includes the developer described above, and appropriately has other structures as necessary. It is preferable that the developer is filled in a storage container whose shape is easily deformed, and has a developer replenishing device that sucks the replenishing developer with a suction pump and supplies the developer to the developing device.

  FIG. 18 is a diagram illustrating an example of the developing device. The developing device 40 disposed facing the photoconductor 20 includes a developing sleeve 41, a developer containing member 42, a doctor blade 43, a support case 44, and the like.

To a support case 44 having an opening on the side of the photoconductor 20, a toner hopper 45 serving as a toner storage unit that stores the toner 21 is joined. A developer containing portion 46 containing toner 21 and a carrier 23 adjacent to the toner hopper 45 is used to stir the toner 21 and the carrier 23 and impart friction / release charge to the toner 21. A developer stirring mechanism 47 is provided. Inside the toner hopper 45, a toner agitator 48 and a toner replenishing mechanism 49 are disposed as toner supplying means rotated by a driving means (not shown). The toner agitator 48 and the toner replenishing mechanism 49 send out the toner 21 in the toner hopper 45 toward the developer accommodating portion 46 while stirring. A developing sleeve 41 is disposed in a space between the photoconductor 20 and the toner hopper 45. The developing sleeve 41, which is rotationally driven in the direction of the arrow in the figure by a driving means (not shown), is disposed in the interior thereof so as not to change relative position with respect to the developing device 40 in order to form a magnetic brush by the carrier 23. In addition, it has a magnet (not shown) as magnetic field generating means. A doctor blade 43 is integrally attached to the developer accommodating member 42 on the side facing the side attached to the support case 44. In this example, the doctor blade 43 is disposed in a state where a certain gap is maintained between the tip of the doctor blade 43 and the outer peripheral surface of the developing sleeve 41.

(Image forming apparatus and image forming method)
The image forming apparatus includes: an electrostatic latent image forming unit that forms an electrostatic latent image on a photoconductor; and the electrostatic latent image formed on the photoconductor using a developer described above to develop a toner image. Developing means for containing the developer, transfer means for transferring the toner image formed on the photoreceptor to a recording medium, and fixing means for fixing the toner image transferred to the recording medium. Including. The developing means is not particularly limited and may be appropriately selected depending on the intended purpose. However, a means for developing using a developer having a magnetic brush to form a toner image is preferable. Examples of the developing unit include the developing device.

  The image forming method includes an electrostatic latent image forming step of forming an electrostatic latent image on a photoreceptor, and developing the electrostatic latent image formed on the photoreceptor using the developer described above to form a toner image. A developing step for transferring the toner image, a transfer step for transferring the toner image formed on the photoreceptor to a recording medium, and a fixing step for fixing the toner image transferred to the recording medium. There is no restriction | limiting in particular as said image development process, Although it can select suitably according to the objective, The process which develops using the developing agent in which the magnetic brush was formed, and forms a toner image is preferable.

  An embodiment of an image forming apparatus will be described with reference to FIG.

  As shown in FIG. 19, first, the photoconductor 20 is rotationally driven at a predetermined peripheral speed, and the charging device 32 uniformly charges the peripheral surface of the photoconductor 20 to a predetermined positive or negative potential. Next, the peripheral surface of the photoreceptor 20 is exposed by the exposure device 33, and electrostatic latent images are sequentially formed. Further, the electrostatic latent image formed on the peripheral surface of the photoconductor 20 is developed by the developing device 40 using a developer containing a carrier and toner to form a toner image. Next, the toner image formed on the peripheral surface of the photoconductor 20 is synchronized with the rotation of the photoconductor 20 and sequentially onto the transfer paper fed between the photoconductor 20 and the transfer device 50 from the paper feed unit. Transcribed. Further, the transfer paper onto which the toner image has been transferred is separated from the peripheral surface of the photoconductor 20, introduced into the fixing device and fixed, and then printed out as a copy (copy) to the outside of the image forming apparatus. . On the other hand, after the toner image is transferred, the surface of the photoreceptor 20 is cleaned by the cleaning device 60 after the remaining toner is removed, and then the charge is removed by the charge eliminating device 70 and repeatedly used for image formation.

  It is preferable that the image forming apparatus replenishes the above-described replenishment developer to the developing device and performs development while discharging the excess developer in the developing device. The replenishment developer is preferably filled in a storage container whose shape is easily deformed, and is provided with a developer replenishment device that sucks the replenishment developer with a suction pump and supplies the replenishment developer to the developing device. .

  FIG. 20 is a diagram illustrating another example of the image forming apparatus. The photosensitive member 20 is provided with at least a photosensitive layer on a conductive support, and is driven by driving rollers 24a and 24b, and is charged by a charging device 32, image exposure by an exposure device 33, development by a developing device 40, and corona charging. The transfer using the transfer device 50 having a container, the pre-cleaning exposure by the pre-cleaning exposure light source 26, the cleaning by the brush-like cleaning means 64 and the cleaning blade 61, and the static elimination by the static elimination device 70 are repeated. Pre-cleaning exposure is performed on the photoconductor 20 (of course, in this case, the support is translucent) from the support side.

(Process cartridge)
The process cartridge includes a photoconductor and a developing unit that develops the electrostatic latent image formed on the photoconductor using the developer described above, and is supported by the image forming apparatus.

  An embodiment of a process cartridge will be described with reference to FIG.

  As shown in FIG. 21, the process cartridge 10 develops the photosensitive member 11, the charging device 12 for charging the photosensitive member 11, and the electrostatic latent image formed on the photosensitive member using the developer. A developing device 13 for forming a toner image, and a cleaning device 14 for removing the toner remaining on the photosensitive member after transferring the toner image formed on the photosensitive member to a recording medium. It can be attached to and detached from the main body of an image forming apparatus such as a printer.

  The process cartridge is preferably one that discharges excess developer and is newly replenished with developer, and a photoreceptor on which an electrostatic latent image is formed, and an electrostatic latent image on the photoreceptor. And a developing device that visualizes the image, and is detachably mounted on the main body of the image forming apparatus that replenishes the developer for replenishment and discharges the developer from the developing device. It is preferable. Moreover, it is preferable that the developing device in the process cartridge has the developer in the developing device.

  Examples of the present invention will be described below, but the present invention is not limited to the examples.

  In the following description, “part” and “%” mean “part by mass” and “% by mass” unless otherwise specified.

<Core particle manufacturing method>
A production example of the core particles will be described below.

  First, Table 1 shows various characteristics of the ferromagnetic iron oxide particles used as the ferromagnetic iron oxide particles a and the ferromagnetic iron oxide particles b.

(Lipophilic treatment 1)
After 1000 parts of iron oxide particles 1 were charged into the flask and sufficiently stirred, 5.0 parts of a silane coupling agent having an epoxy group (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and the temperature was raised to about 100 ° C. By heating and mixing well for 30 minutes, ferromagnetic iron oxide particles a coated with a coupling agent were obtained.

(Lipophilic treatment 2)
After 1000 parts of iron oxide particles 2 were charged into the flask and sufficiently stirred, 10.0 parts of a silane coupling agent having an epoxy group (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) was added and the temperature was raised to about 100 ° C. By heating and mixing well for 30 minutes, ferromagnetic iron oxide particles b coated with a coupling agent were obtained.

  The flask was charged with 30 parts of ferromagnetic iron oxide particles a subjected to lipophilic treatment 1 and 70 parts of ferromagnetic iron oxide particles b subjected to lipophilic treatment 2 (ra / rb = 1.5), and a stirring speed of 250 rpm. And stirred well for 30 minutes.

<Production of spherical magnetic composite particles (core particle 1)>
Phenol 10 parts 37% formalin 15 parts Mixed powder of ferromagnetic iron oxide particles a powder and b powder 100 parts 25% ammonia water 3.5 parts Water 15 parts The above materials are placed in a 1 L four-necked flask and stirred at 250 rpm. The mixture was heated to 85 ° C. for 60 minutes with stirring, and then reacted and cured at the same temperature for 120 minutes to produce composite magnetic particles composed of ferromagnetic iron oxide particles and a cured phenol resin.

  Next, after cooling the content in the flask to 30 ° C., the supernatant was removed, and the precipitate in the lower layer was washed with water and then air-dried.

  Next, this was dried at 150 to 200 ° C. under reduced pressure (5 mmHg or less) to obtain spherical magnetic composite particles (core particles 1).

The obtained core particles had an average particle diameter of 37 μm, a specific gravity of 3.82 g / cm ³ and a bulk density of 1.92.

<Manufacture of core particles 2-8>
The core particle 2 is operated under the same conditions as the core particle 1 except that the types and mixing ratios of the ferromagnetic iron oxide particles a and b, the type of lipophilic agent, and the production conditions of the core particles are variously changed. ~ 8 was obtained. Production conditions are shown in Tables 2 and 3.

The obtained core particle 2 had an average particle diameter of 42 μm, a specific gravity of 3.50 g / cm ³ , and a bulk density of 1.95. Moreover, the obtained core particle 3 had an average particle diameter of 36 μm, a specific gravity of 3.90 g / cm ³ , and a bulk density of 2.08.

<Manufacture of core particle 9>
74 parts of Fe ₂ O ₃ , 20 parts of MnO ₂ , 5 parts of Mg (OH) 2 and 1 part of ZnO are weighed, mixed in a wet ball mill for 25 hours, pulverized, granulated with a spray dryer and dried. Then, preliminary calcination 1 was performed in an electric furnace at 800 ° C. for 7 hours.

  The obtained calcined product 1 was pulverized for 2 hours with a wet ball mill, granulated and dried with a spray dryer, and then calcined 2 at 900 ° C. for 6 hours with an electric furnace.

  The obtained calcined product 2 was pulverized with a wet ball mill for 5 hours, granulated and dried with a spray dryer, and then subjected to main calcination at 900 ° C. for 12 hours in an electric furnace to produce Mn—Mg ferrite particles (core particles 9 )

The obtained core particle 9 had an average particle diameter of 36 μm, a specific gravity of 5.20 g / cm ³ , and a bulk density of 2.43.

<Manufacture of electroconductive particle 1>
100 g of aluminum oxide (manufactured by Sumitomo Chemical Co., Ltd., AKP-30) was dispersed in 1 liter of water to form a suspension, and this liquid was heated to 70 ° C. A solution obtained by dissolving 100 g of stannic chloride and 3 g of phosphorus pentoxide in 1 liter of 2N hydrochloric acid and 12% by mass of aqueous ammonia were dropped into the suspension over 2 hours so that the pH of the suspension was 7-8. did. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dried powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain conductive particles 1.

  The volume resistivity of the obtained conductive particles 1 was 8 Ω · cm.

<Production of conductive particles 2>
100 g of aluminum oxide (manufactured by Sumitomo Chemical Co., Ltd., AKP-30) was dispersed in 1 liter of water to form a suspension, and this liquid was heated to 70 ° C. To the suspension, a solution of 10 g of stannic chloride and 0.30 g of phosphorus pentoxide dissolved in 100 mL of 2N hydrochloric acid and 12% by mass aqueous ammonia was added for 12 minutes so that the pH of the suspension would be 7-8. It was dripped. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dried powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain conductive particles 2.

  The obtained conductive particles 2 had a volume average particle size of 300 nm and a volume resistivity of 1,200 Ω · cm.

<Production of conductive particles 3>
100 g of aluminum oxide (manufactured by Sumitomo Chemical Co., Ltd., AKP-30) was dispersed in 1 liter of water to form a suspension, and this liquid was heated to 70 ° C. To the suspension, a solution of 150 g of stannic chloride and 4.5 g of phosphorus pentoxide in 1.5 liters of 2N hydrochloric acid and 12% by mass aqueous ammonia was added so that the suspension had a pH of 7-8. It was added dropwise over time. After dropping, the cake obtained by filtering and washing the suspension was dried at 110 ° C. Next, this dry powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain conductive particles 3.

  The obtained conductive particles 3 had a volume average particle size of 300 nm and a volume resistivity of 3 Ω · cm.

<Production of conductive particles 4>
A tin oxide fine powder (primary particle size 50 nm) having a BET surface area of 50 m 2 / g is heated in contact with acetone gas in a nitrogen atmosphere and maintained at a temperature of 300 ° C. for 2 hours to carry out surface modification treatment, thereby conducting Sex particles 4 were obtained.

<Conductive particles 5>
As the conductive particles 5, Black Pearls-2000 (manufactured by Cabot, specific surface area 1,500 mm ² / g, aspect ratio 3) was used.

<Synthesis of Resin 1>
300 g of toluene was charged into a flask equipped with a stirrer, and the temperature was raised to 90 ° C. under a nitrogen gas stream. Subsequently, 84.4 g (200 mmol, Silaplane TM-0701T, manufactured by Chisso Corporation), 3-methacryloxypropylmethyldiethoxysilane 39 g (150 mmol), and methyl methacrylate were added thereto. A mixture of 65.0 g (650 mmol) and 2,2′-azobis-2-methylbutyronitrile 0.58 g (3 mmol) was added dropwise over 1 hour. After completion of the dropwise addition, a solution prepared by dissolving 0.06 g (0.3 mmol) of 2,2′-azobis-2-methylbutyronitrile in 15 g of toluene was further added (2,2′-azobis-2-methylbutyro A total amount of nitrile 0.64 g, 3.3 mmol) was mixed at 90 ° C. to 100 ° C. for 3 hours and radical copolymerized to obtain a methacrylic copolymer (resin 1). The weight average molecular weight of the obtained resin 1 was 33,000. Subsequently, it diluted with toluene so that the non volatile matter of this resin 1 might be 25 mass%. The viscosity of the resin 1 solution thus obtained was 8.8 mm ² / s, and the specific gravity was 0.91.

<Synthesis of Resin 2>
In Production Example 3-1, the radical copolymer was changed in the same manner as in Resin 1 except that 39 g (150 mmol) of 3-methacryloxypropylmethyldiethoxysilane was replaced with 37.2 g (150 mmol) of 3-methacryloxypropyltrimethoxysilane. A methacrylic copolymer (Resin 2) was obtained by polymerization.

The weight average molecular weight of the obtained methacrylic copolymer was 34,000. Subsequently, it diluted with toluene so that the non volatile matter of this methacrylic copolymer solution might be 25 mass%. The viscosity of the copolymer solution thus obtained was 8.7 mm ² / s, and the specific gravity was 0.91.

<Resin 3>
As the resin 3, a silicone resin solution (SR2410, manufactured by Toray Dow Corning Silicone) was used.

<Preparation of resin 4>
118.69 parts by mass of 50% by mass acrylic resin solution (Hitaroid 3001, manufactured by Hitachi Chemical Co., Ltd.), 37.18 parts by mass of 70% by mass guanamine solution (My Coat 106, manufactured by Mitsui Cytec Co., Ltd.) Then, 0.68 parts by mass of 40% by mass of an acidic catalyst (Catalyst 4040, manufactured by Mitsui Cytec Co., Ltd.) was mixed to obtain a protective layer coating solution (resin 4 coating solution).

<Preparation of base particle A>
<< Dissolution of toner material or preparation of dispersion >>
-Synthesis of unmodified polyester resin (low molecular weight polyester resin)-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 84 parts by mass of bisphenol A propion oxide 3 mol adduct, 274 parts by mass of terephthalic acid, and dibutyltin oxide 2 parts by mass were added and reacted at 230 ° C. under normal pressure for 8 hours. Subsequently, the obtained reaction liquid was reacted under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to synthesize an unmodified polyester resin.

  The obtained unmodified polyester resin had a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 5,600, and a glass transition temperature (Tg) of 55 ° C.

-Preparation of masterbatch (MB)-
1,000 parts by weight of water, 540 parts by weight of carbon black (“Printex35”; manufactured by Degussa, DBP oil absorption = 42 mL / 100 g, pH = 9.5), and 1,200 parts by weight of the unmodified polyester resin, Mixing was performed using a Henschel mixer (Mitsui Mining Co., Ltd.). The mixture was kneaded for 30 minutes at 150 ° C. with two rolls, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron) to prepare a master batch.

-Preparation of toner material phase-
In a beaker, 100 parts by mass of the unmodified polyester resin and 130 parts by mass of ethyl acetate were stirred and dissolved. Next, 10 parts by mass of carnauba wax (molecular weight = 1,800, acid value = 2.5, penetration = 1.5 mm (40 ° C.)) and 10 parts by mass of the master batch were charged, and a bead mill (“Ultra Visco” Mill "; manufactured by Imex Co., Ltd.), a raw material solution was prepared by three passes under the condition that the liquid feeding speed was 1 kg / hr, the disk peripheral speed was 6 m / s, and 80% by volume of 0.5 mm zirconia beads were filled, A toner material solution or dispersion (toner material phase) was prepared.

-Preparation of resin particles 1-
In a reaction vessel in which a stir bar and a thermometer are set, 683 parts by mass of water, 16 parts by mass of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 83 parts by mass of styrene, When 83 parts by weight of methacrylic acid, 110 parts by weight of butyl acrylate and 1 part by weight of ammonium persulfate were charged and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts by mass of a 1% by mass ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours to vinyl resin (a copolymer of sodium salt of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate) An aqueous dispersion of [Resin particle dispersion 1] was obtained. It was 9 nm when the volume average particle diameter of [resin particle dispersion liquid 1] was measured with LA-920 (manufactured by Horiba, Ltd.).

-Preparation of aqueous medium phase-
660 parts by mass of water, 25 parts by mass of the above [resin particle dispersion 1], 25 parts by mass of an aqueous solution of 48.5% by mass of sodium dodecyl diphenyl ether disulfonate (“Eleminol MON-7”; manufactured by Sanyo Chemical Industries, Ltd.), and 60 parts by mass of ethyl acetate was mixed and stirred to obtain a milky white liquid (aqueous medium phase 1).

-Preparation of emulsion or dispersion-
150 parts by mass of aqueous medium phase 1 is put in a container, and stirred at a rotational speed of 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), and 100 parts by mass of the toner material dissolved or dispersed therein Was added and mixed for 10 minutes to obtain an emulsified or dispersed liquid (emulsified slurry A).

-Removal of organic solvent-
In a flask equipped with a deaeration pipe, a stirrer, and a thermometer, 100 parts by mass of the emulsified slurry A was charged, and the solvent was removed by removing the solvent under reduced pressure at 30 ° C for 12 hours while stirring at a stirring peripheral speed of 20 m / min. Obtained.

-Washing-
After filtering the whole amount of the solvent removal slurry A under reduced pressure, 300 parts by mass of ion-exchanged water was added to the filter cake, mixed and redispersed (at 12,000 rpm for 10 minutes) with a TK homomixer, and then filtered. To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filtered three times to obtain a washing slurry A.

-Heat treatment-
The resulting washed slurry A was aged at 45 ° C. for 10 hours, filtered and a heat-treated cake was obtained.

-Drying-
After the heat treatment, the cake was dried at 45 ° C. for 48 hours in a forward air dryer, and sieved with a mesh having an opening of 75 μm to obtain base particles A.

<Preparation of base particle B>
-Synthesis of crystalline polyester resin-
In a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, 1,6-hexanediol 2,300 g, fumaric acid 2,530 g, trimellitic anhydride 291 g, and hydroquinone4. 9 g was added, reacted at 160 ° C. for 5 hours, then heated to 200 ° C. and reacted for 1 hour, and further reacted at 8.3 kPa for 1 hour to obtain crystalline polyester resin 1.

-Synthesis of amorphous polyester resin (low molecular weight polyester resin)-
In a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, 229 parts by mass of bisphenol A ethylene oxide side 2 mol adduct, 529 parts by mass of bisphenol A propylene oxide 3 mol adduct, 208 parts by mass of terephthalic acid, 46 parts by mass of adipic acid and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. for 7 hours at normal pressure, and further reacted for 4 hours at a reduced pressure of 10 mmHg to 15 mmHg. 44 parts by mass of merit acid was added and reacted at 180 ° C. and normal pressure for 2 hours to obtain an amorphous polyester resin.

-Synthesis of polyester prepolymer (prepolymer)-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 81 parts by mass of bisphenol A propylene oxide 2 mol adduct, 283 parts by mass of terephthalic acid, 22 parts by mass of merit acid and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 8 hours, and further reacted at reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain [Intermediate polyester]. The [intermediate polyester] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

  Next, 410 parts by mass of [intermediate polyester], 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate were placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and reacted at 100 ° C. for 5 hours. [Prepolymer] was obtained. [Prepolymer] had a free isocyanate mass% of 1.53%.

-Synthesis of ketimine compounds-
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound]. The amine value of [ketimine compound] was 418.

-Synthesis of master batch (MB)-
1,200 parts by mass of water, carbon black (manufactured by Printex 35 Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5] 540 parts by mass, 1,200 parts by mass of the amorphous polyester resin synthesized above were added, The mixture was mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a [masterbatch].

-Preparation of pigment / WAX dispersion-
In a container in which a stir bar and a thermometer are set, 378 parts by weight of [amorphous polyester resin], 110 parts by weight of Carnauba WAX, 22 parts by weight of CCA (salicylic acid metal complex E-84: manufactured by Orient Chemical Industry Co., Ltd.), and acetic acid 947 parts by mass of ethyl was charged, heated to 80 ° C. with stirring, maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts by mass of [Masterbatch] and 500 parts by mass of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution].

  [Raw material solution] 1,324 parts by mass were transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were 80. Carbon black and WAX were dispersed under the conditions of volume% filling and 3 passes. Next, 1,02.3 parts by mass of a 65% by mass ethyl acetate solution of [amorphous polyester resin] was added, followed by one pass with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion]. The solid content concentration of the [pigment / WAX dispersion] (130 ° C., 30 minutes) was 50 mass%.

-Preparation of crystalline polyester dispersion-
100 g of [Crystalline Polyester Resin] and 400 g of ethyl acetate were put in a metal 2 L container, dissolved by heating at 75 ° C., and then rapidly cooled in an ice-water bath at a rate of 27 ° C./min. To this, 500 mL of glass beads (diameter 3 mm) was added, and pulverized for 10 hours with a batch type sand mill apparatus (manufactured by Campehapio Co., Ltd.) to obtain [Crystalline Polyester Dispersion].

-Synthesis of organic particle emulsion-
In a reaction vessel in which a stir bar and a thermometer are set, 683 parts by mass of water, 11 parts by mass of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30: Sanyo Chemical Industries, Ltd.), 138 parts by mass of styrene, When 138 parts by weight of methacrylic acid and 1 part by weight of ammonium persulfate were charged and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts by mass of a 1% by mass ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and then an aqueous dispersion of vinyl resin (styrene salt copolymer of styrene-methacrylic acid-methacrylic acid ethylene oxide adduct sulfate). [Resin particle dispersion 2] was obtained. The volume average particle diameter of the [resin particle dispersion 2] measured by LA-920 was 0.14 μm.

-Preparation of aqueous medium phase 2-
990 parts by weight of water, 83 parts by weight of [resin particle dispersion 2], 37 parts by weight of a 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7: Sanyo Chemical Industries, Ltd.), and 90 parts by weight of ethyl acetate Were mixed and stirred to obtain a milky white liquid (aqueous medium phase 2).

-Emulsification / solvent removal-
[Pigment / WAX Dispersion 2] 664 parts by mass, [Prepolymer] 109.4 parts by mass, [Crystalline Polyester Dispersion] 73.9 parts by mass, and [Ketimine Compound] 4.6 parts by mass are put in a container. After mixing for 1 minute at 5,000 rpm with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), add 1,200 parts by mass of [Aqueous medium phase 2] to the container, and with a TK homomixer, rotating at 13,000 rpm. The mixture was mixed for 20 minutes to obtain [Emulsion slurry 2].

  [Emulsion slurry 2] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 2].

-Cleaning and drying-
[Dispersion Slurry 2] After 100 parts by mass of vacuum filtration,
(1): 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts by mass of 10 mass% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(4): Add 300 parts by mass of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filter twice to perform [Filter cake 2]. Obtained.

  [Filter cake 2] was dried with a circulating dryer at 45 ° C. for 48 hours, and sieved with a mesh having an opening of 75 μm to obtain base particles B.

<Preparation of external additive>
-Preparation of coalesced particles (silane-treated silica) (silica 1-3 and silica 6-8)-
In the production of coalesced particles, fused silica was produced by secondary agglomeration with various treatment agents using silica primary particles having various average particle diameters. The degree of coalescence was adjusted according to the average particle diameter of the silica primary particles used, the treatment agent, the mixing ratio of the silica primary particles and the treatment agent, and the treatment conditions (firing temperature, firing time). Mixing of the silica primary particles and the treatment agent was performed using a spray dryer.

-Preparation of coalesced particles (non-spherical dry silica) (silica 4 and 5)-
The coalesced particles were manufactured by the dry method using the apparatus shown in FIG.

<Preparation of Toner A>
With respect to 100 parts by mass of the base particle A, 2.0 parts by mass of fused silica (silica 1) in Table 1, 2.0 parts by mass of silica having an average particle diameter of 10 nm to 20 nm, and titanium oxide having an average particle diameter of 20 nm 0 6 parts by mass was mixed with a Henschel mixer, and passed through a sieve having a mesh size of 500 mesh to obtain toner A.

<Preparation of toners B to E and G to J>
Toners B to E and G to J were obtained in the same manner as toner A except that silica 1 was replaced with silica.

<Preparation of Toner F>
Toner F was obtained in the same manner as toner A, except that base particle A was replaced by base particle B and silica 1 was replaced by silica 4.

Example 1
<Manufacture of carriers>
In order to form a protective layer for the carrier, a protective layer forming solution A (solid content: 10% by mass) having the following composition was prepared. This protective layer forming solution A was applied to 1,000 parts by mass of the core particles 1 and dried. Here, application | coating thru | or drying were performed using the fluid bed type | mold coating apparatus which controlled the temperature in a fluid tank to each 70 degreeC. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain a carrier. Table 4 shows the characteristics of the carrier.

-Composition of protective layer forming solution A-
Resin for protective layer (resin 1, solid content 75% by mass) 30 parts by mass Conductive particles 1 56 parts by mass Catalyst 4 parts by mass (titanium diisopropoxybis (ethylacetoacetate ))
(Orgatechs TC-750, manufactured by Matsumoto Fine Chemical Co., Ltd.)
Silane coupling agent: 0.6 parts by mass (SH6020, manufactured by Toray Dow Corning)
・ Toluene: remainder <Development of developer>
The carrier (930 parts by mass) obtained above and a toner (70 parts by mass) for a commercially available digital full color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.) are mixed, and the mixture is used at 81 rpm for 5 minutes using a turbuler mixer. The developer for evaluation was prepared by stirring. The replenishment developer was prepared using the carrier and the toner so as to have the premix ratio shown in Table 4 (the content ratio (mass%) of the carrier in the replenishment developer).

(Evaluation)
The developer was evaluated according to various evaluation items shown below. The results are shown in Table 6.

<Evaluation of ghost images>
Each produced developer and each replenishment developer are set in a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.), and a character chart with an image area of 8% (size of one character: about 2 mm × 2 mm) ) Was output 100,000 sheets. Thereafter, the vertical band chart shown in FIG. 22 was printed, and the influence of the immediately preceding image history was evaluated by measuring the density difference between the one round of the sleeve (a) and the one round after (b). For the measurement, a color value measuring device (X-Rite 938, manufactured by X-Rite) was used. Measurement was performed at three locations of the center, rear, and front of the sleeve, and the average density difference was taken as ΔID. The evaluation criteria were as follows.

<< Evaluation criteria >>
◎: ΔID is 0.01 or less ○: ΔID is more than 0.01 and 0.03 or less Δ: ΔID is more than 0.03 and 0.06 or less ×: ΔID is more than 0.06 Here, ◎, ○, △, and × are ◎: very good, ◯: good, △: acceptable, ×: unusable levels for practical use, ◎, ○, and △ are acceptable, It was rejected.

<Evaluation of initial carrier adhesion>
Each developer is set in a remodeled machine obtained by remodeling a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.), the background potential is fixed at 150 V, a non-image chart, and a 1 cm × 1 cm BOX is 3 mm apart. Developed the charts lined with.

  At the time of no image chart, the number of carriers adhering to the surface of the photoreceptor was counted by five visual field observations with a magnifying glass, and the average number of carriers adhering per 100 cm 2 was taken as the carrier adhering amount.

<< Evaluation criteria >>
◎: 20 or less ○: 21 or more and 60 or less Δ: 61 or more and 80 or less ×: 81 or more ◎, ○ and Δ were accepted, and x was rejected.

  During the BOX chart, the transfer current was reduced to 2 μA, and white spots on the A3 image were evaluated.

<< Evaluation criteria >>
◎: 5 or less ○: 6 or more and 10 or less △: 11 or more and 30 or less ×: 31 or more ◎, ○ and Δ were accepted, and x was rejected.

<Evaluation of edge effect>
Each developer was set in a modified machine obtained by modifying a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.), and a test pattern having a large area image was output. In the obtained image pattern, the difference between the image density at the center and the image density at the edge was visually evaluated according to the following evaluation criteria.

<< Evaluation criteria >>
A: There is no difference. O: There is a slight difference. Δ: There is a difference but it is acceptable. X: There is a difference to an unacceptable level. A, O, and Δ are accepted and x is rejected.

<Evaluation of image definition>
Each produced developer is set in a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.), and a character chart with a 5% image area (size of one character: about 2 mm × 2 mm) is output. Evaluation was made based on the reproducibility of the character image portion, and ranking was performed as follows.

<< Evaluation criteria >>
◎: Very good ○: Good △: Acceptable level ×: Unpractical level ◎, ○ and Δ were accepted, and x was rejected.

<Evaluation of toner dust>
When the image was formed under the same image forming conditions as the evaluation of the fineness of the image, the toner dust on the portion other than the character portion (white portion) was visually observed and evaluated according to the following evaluation criteria.

<< Evaluation criteria >>
A: The toner is not observed at all and is in a good state.

  ○: Toner stains are slightly observed but in good condition.

  (Triangle | delta): It is a grade in which dirt is observed slightly and does not become a problem.

  X: Very dirty and out of the allowable range.

  ◎, ○, and Δ were accepted, and x was rejected.

<Evaluation of color mixing>
The color stain (color mixture) was evaluated by setting each developer on a commercially available digital full-color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.) and stirring the developing unit alone for 1 hour. The developer thus obtained was developed and fixed, and the L * 1, a * 1, and b * 1 values of the CIE color system at the location where the image density was 1.5 were determined. On the other hand, in order to obtain an image free from color stains, an image formed with toner alone (including fixing) without being brought into contact with the carrier is prepared, and the CIE table of the portion where the image density is 1.5 as described above. L * 0, a * 0, and b * 0 values of the color system were obtained. The color difference ΔE between the two images obtained in this way is obtained by the following formula. If ΔE ≦ 3.0, there is no problem in actual use, so it is accepted (O), and ΔE> 3.0 is a problem in actual use, so it is rejected. (X).

ΔE = {(L * 0−L * 1) ² + (a * 0−a * 1) ² + (b * 0−b * 1) ² } ^1/2
<Durability evaluation>
Each produced developer was set in a remodeled machine obtained by remodeling a commercially available digital full color printer (RICOH Pro C901, manufactured by Ricoh Co., Ltd.), and 100,000 sheets of single color running evaluation were performed. After this running was completed, the carrier adhesion, the charge reduction amount, and the resistance reduction amount of the carrier were evaluated. The carrier adhesion was evaluated by the same method and evaluation criteria as the above-described initial carrier adhesion evaluation.

<< Evaluation of resistance drop >>
The amount of decrease in resistance is calculated by putting a carrier before running between electrodes of a resistance measurement parallel electrode (gap 2 mm), applying a DC voltage of 1000 V, and measuring a resistance value after 30 seconds as a high resist meter (4329A + LJK 5HVLVWDQFH 0HWHU; Yokogawa From the value (R1) obtained by converting the value measured by Hewlett-Packard Co.) into the volume resistivity, the carrier in which the toner in the developer after running can be removed by the blow-off device (see FIG. 23), The value obtained by subtracting the value (R2) measured by the same method as the resistance measuring method was used. In FIG. 23, reference numeral 3 indicates a carrier, reference numeral 5 indicates toner, and reference numeral 7 indicates a blow gauge.

  If the absolute value of the resistance reduction amount is within 3.0 Log (Ω · cm), it is at a level causing no problem in actual use.

  In addition, the cause of the resistance change is scraping of the resin film of the carrier, spent toner component, detachment of particles having a large particle size in the carrier coating film, etc. it can.

<< Evaluation of charge reduction >>
The charge reduction amount was measured by a general blow-off method (TB-200, manufactured by Toshiba Chemical Co., Ltd.) on a sample that was mixed and frictionally charged at a ratio of 7% by mass of toner to 93% by mass of the carrier before running. The carrier obtained by removing the toner in the developer after running by the blow-off device was subtracted from the charged amount (Q1) obtained by subtracting the charged amount (Q2) measured by the same method as described above.

  If the charge reduction amount is within 10.0 μc / g, there is no problem in practical use. Further, since the cause of the decrease in the charge amount is the toner spent on the carrier surface, the toner spent can be evaluated based on the charge decrease amount.

(Examples 2 to 21 and Comparative Examples 1 to 10)
A carrier was produced in the same manner as in Example 1 except that the type of core particles, the type of particles, the dispersion method, the production method, and the like were changed as shown in Table 4.

  A developer was prepared and evaluated in the same manner as in Example 1 except that the carrier shown in Table 4 was used. The results are shown in Table 6.

(Examples 22-50 and Comparative Examples 11-21)
In Examples 22 to 50 and Comparative Examples 11 to 21, the toners shown in Table 5 were used.

  A carrier was produced in the same manner as in Example 1 except that the type of core particles, the type of particles, the dispersion method, the production method and the like were changed as shown in Table 4 in the production of the carrier of Example 1.

  In Example 1, a developer was prepared and evaluated in the same manner as in Example 1 except that the toner shown in Table 5 and the carrier shown in Table 4 were used. The results are shown in Table 6. In Examples 22 to 50 and Comparative Examples 11 to 21, the following evaluation was also performed.

  In Table 4, the dispersing means represents a dispersing means for dispersing conductive particles in the protective layer forming solution.

DESCRIPTION OF SYMBOLS 1a Electrode 1b Electrode 2 Fluororesin container 3 Carrier 5 Toner 7 Brokerage 10 Process cartridge 11 Photoconductor 12 Charging device 13 Developing device 14 Cleaning device 20 Photoconductor 21 Toner 23 Carrier 24a, 24b Driving roller 26 Pre-cleaning exposure light source 32 Charging Device 33 Exposure device 40 Developing device 41 Developing sleeve 42 Developer containing member 43 Doctor blade 44 Support case 45 Toner hopper 46 Developer containing portion 47 Developer stirring mechanism 48 Toner agitator 49 Toner replenishing mechanism 50 Transfer device 60 Cleaning device 61 Cleaning blade 64 Brush-like cleaning means 70 Neutralizing device 101 Toner 102 Base particles 103 External additive 111 Core particles 112 Resin 113 Fine particles 120 Developing sleeve

JP 2011-13676 A

Claims (16)

Having toner and carrier,
The toner has base particles containing a colorant, a release agent and a binder resin, and a non-spherical external additive,
The carrier has a protective layer containing a resin and conductive particles formed on the surface of the core particles in which magnetic particles are dispersed in a binder resin.
Developer, wherein the protective layer has an average height difference is 3.0μm or less than 0.02 [mu] m. The external additive includes coalesced particles in which a plurality of primary particles are coalesced,
Assuming that the median diameter of the coalesced particles is D ₅₀ [nm] and the particle diameter of the coalesced particles from the smaller particle size side is 10%, D ₁₀ [nm], the formula D ₅₀ / D ₁₀ ≦ 1.2
The developer according to claim 1, wherein: The external additive includes coalesced particles in which a plurality of primary particles are coalesced,
After putting 0.5 g of the coalesced particles and 49.5 g of the carrier into a 50 mL bottle, the number of primary particles not coalesced among 1000 particles stirred for 10 minutes at 67 Hz using a rocking mill is 300. The developer according to claim 1, wherein the developer is one or less.   The developer according to claim 1, wherein the carrier has an arithmetic average roughness Ra of 0.40 μm or more and 0.85 μm or less.   The developer according to any one of claims 1 to 4, wherein the magnetic particles include a plurality of ferromagnetic iron oxide particles having different average particle sizes. Developer according to any one of claims 1 to 5, wherein the weight ratio of the conductive particles to the resin contained in the protective layer is 1 to 3. Development according to the protective layer, any one of claims 1 to 6 and the ratio of Volume average particle diameter of the conductive particles to the average thickness is characterized in that 0.01 to 1.00 Agent. The conductive particles are either common logarithm of the powder specific resistivity -3 [log (Ω · cm) ] of more than 3 [log (Ω · cm) ] according to claim 1 to 7, characterized in that less is The developer according to one item. The conductive particles, alumina particles, silica particles, titanium dioxide particles, any one of claims 1 to 8, characterized in that it comprises barium sulphate particles, a least one selected from the group consisting of tin dioxide particles and carbon The developer according to item. Resin contained in the protective layer, the developer according to any one of claims 1 to 9, characterized in that it comprises a silicone resin. The resin contained in the protective layer, the developer according to any one of claims 1 to 10, characterized in that it comprises a cured product of a composition comprising a silane coupling agent and silicone resins. The resin contained in the protective layer has a general formula
(In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is an alkyl group having 1 to 4 carbon atoms, and m is an integer of 1 to 8)
Structural units and general formulas derived from compounds represented by
(In the formula, R ³ is a hydrogen atom or a methyl group, R ⁴ is an alkyl group having 1 to 4 carbon atoms, and R ⁵ is an alkyl group or carbon number having 1 to 8 carbon atoms. Is an alkoxy group of 1 to 4, and n is an integer of 1 to 8.
The content of the structural unit derived from the compound represented by the general formula (A) is 10 mol% or more and 90 mol% or less, and is represented by the general formula (B). developer according to any one of claims 1 to 11 the content of the constitutional unit derived from the compound is characterized in that it comprises a crosslinked product of a copolymer is less 10 mol% or more 90 mol% that. Means for forming an electrostatic latent image on the photoreceptor;
An electrostatic latent image formed on the photosensitive member, using a developer according to any one of claims 1 to 12, means for forming a toner image,
Means for transferring a toner image formed on the photoreceptor to a recording medium;
An image forming apparatus comprising means for fixing a toner image transferred to the recording medium. Developer containing container, characterized in that it comprises a developer according to any one of claims 1 to 12. A photosensitive member and an electrostatic latent image formed on the photosensitive member are developed using the developer according to any one of claims 1 to 12 , and a unit for forming a toner image is integrally supported. And
A process cartridge which is detachable from a main body of an image forming apparatus. Having toner and carrier,
The toner has base particles containing a colorant, a release agent and a binder resin, and a non-spherical external additive,
The carrier has a protective layer containing a resin and conductive particles formed on the surface of the core particles in which magnetic particles are dispersed in a binder resin.
The protective layer has an average height difference is at 3.0μm or less than 0.02 [mu] m,
A replenishing developer, wherein a mass ratio of the toner to the carrier is 2 or more and 50 or less.