JP5625713B2 - Cleaning device and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a facsimile, and a printer.

  In recent years, image forming apparatuses such as copiers, facsimiles, and printers that use electrophotography have tended to use small particle size toners for the purpose of improving image quality. In the direction of lowering the melting point. As the particle size and the melting point are lowered, the fluidity of the toner is deteriorated, and troubles such as defective conveyance of the waste toner and toner fixation due to poor conveyance are likely to occur in the waste toner conveyance path.

  On the other hand, JP 2004-361480 A (Patent Document 1) describes a cleaning device including a toner transport device that discharges toner to the outside of a unit by free-falling from an opening of a discharge port. Has been.

  However, in the configuration in which the toner freely falls by gravity in the transport path for discharging from inside the unit, in the case of toner having poor fluidity, the waste toner cannot be directly discharged to the waste toner through the free fall path, and the toner pool There is a problem that is likely to occur.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems in a conventional cleaning device, and to provide a cleaning device that can transport and discharge waste toner outside the unit without fixing the toner, and an image forming apparatus including the cleaning device. To do.

According to the present invention, there is provided a removing means for removing toner on an image carrier on which a toner image is carried on a surface, and a conveying screw for conveying the toner removed by the removing means toward a toner discharge portion. The cleaning device includes a staying toner scraping unit that is provided in the toner discharge portion and is swung by the transport screw , and the staying toner scraping unit is in contact with the transport screw and swings first. This can be solved by being an agitator comprising a swing part and a second swing part that swings in conjunction with the swing of the first swing part .

Preferably, the agitator has a rotation shaft, and the first rocking portion and the second rocking portion are supported by the rotation shaft and rotate.
Moreover, it is preferable when the said rotating shaft is arrange | positioned in parallel with the axis | shaft of the said conveyance screw.

Moreover, it is preferable that the first swinging portion is provided in a comb-like shape including a plurality of members arranged at intervals along the rotation axis direction.
Further, when the coil pitch of the conveying screw is p, the pitch of the comb teeth of the first swinging portion is preferably k × p (k is a coefficient).

Further, when the coil pitch of the conveying screw is p, it is preferable that the pitch of the comb teeth of the first swing portion is k × p + α (k is a coefficient).
The conveying screw and the agitator are accommodated in a casing of the cleaning device, the toner discharge portion is provided in a part of the casing, and the first swinging portion is made of a flexible material, It is preferable that the first swinging portion comes into contact with the casing when swinging in contact with the conveying screw.

Further, it is preferable that the toner discharge portion is provided below the conveying screw.
The staying toner scraping means is preferably a conductive material.
In addition, according to the present invention, the above problem is solved by an image forming apparatus including the cleaning device according to any one of claims 1 to 9 .

The cleaning device is preferably a device for cleaning the intermediate transfer member.
Further, it is preferable that the cleaning device is a device for cleaning the photosensitive member.

  The volume average particle diameter is 3 to 8 [μm], the value obtained by dividing the volume average particle diameter by the number average particle diameter is in the range of 1.00 to 1.40, and the shape factor SF-2 is 100. It is preferable to use a toner of ~ 190.

  Further, as the toner, at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. It is preferable to use those obtained by the reaction or both.

  Further, as the toner, a value obtained by dividing the single axis r2 of the toner particle by the major axis r1 is in the range of 0.5 to 1.0, and the toner particle thickness r3 (where r1 ≧ r2 ≧ r3) is simply set. It is preferable to use one having a value divided by the axis r2 in the range of 0.7 to 1.0.

  According to the cleaning device of the present invention, since the staying toner scraping means is provided in the toner discharge portion, even when the fluidity of the toner collected by the cleaning device is lowered, the toner can be scraped and the toner is fixed. It is possible to discharge the waste toner out of the cleaning device unit without causing it.

Further , the waste toner can be unraveled by an agitator configured to swing the second swinging portion by swinging the first swinging portion in contact with the conveying screw.

The arrangement of claim 2, it is possible to disentangle the waste toner in a simple construction of the agitator and the first oscillating member and the second oscillating member is rotated by being supported by the rotary shaft.
According to the configuration of the third aspect , since the rotating shaft of the agitator is disposed in parallel with the shaft of the conveying screw, the agitator can be swung easily by the conveying screw.

According to the configuration of the fourth aspect , since the first swinging portion of the agitator is provided in a comb shape, the agitator can be swung by the coil of the conveying screw.
According to the configuration of claim 5 , when the coil pitch of the conveying screw is p, the pitch of the comb teeth of the first oscillating portion is k × p (k is a coefficient), so that a large rotational force is obtained in the agitator. It is done.

According to the configuration of claim 6 , when the pitch of the comb teeth of the first oscillating portion is k × p + α (k is a coefficient), the shock at the time of contact is reduced as compared with the case where the pitch is k × p, The generated sound is reduced and a soundproofing effect can be obtained.

According to the configuration of the seventh aspect , the first swinging portion made of a flexible material contacts the casing when the first swinging portion swings in contact with the conveying screw, thereby utilizing the elastic force of the first swinging portion. To swing the agitator.

According to the configuration of the eighth aspect , since the toner discharge portion is provided below the conveying screw, the waste toner can be discharged out of the unit by free fall from the toner discharge portion. Further, the waste toner that has been scraped by the agitator can be efficiently discharged.

According to the configuration of the ninth aspect , friction charging of the agitator can be prevented, and toner discharge performance can be improved.
According to the image forming apparatus of the tenth aspect , since the image bearing member can be satisfactorily cleaned by providing the cleaning device capable of discharging the waste toner to the outside of the unit without the toner adhering to the toner discharge portion, the image quality can be improved over time. Can be maintained.

According to the configuration of the eleventh aspect , since the intermediate transfer member can be cleaned well, a high-quality image can be formed.
According to the structure of the twelfth aspect , since the photosensitive member can be cleaned well, a high-quality image can be formed.

According to the structures of claims 13 to 15 , the effect of preventing toner sticking can be remarkably obtained with respect to the toner having poor fluidity.

1 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus including a cleaning device according to the present invention. FIG. 4 is a cross-sectional view illustrating a configuration of an intermediate transfer member cleaning device. It is sectional drawing of the longitudinal direction of the cleaning apparatus. FIG. 4 is a partial perspective view showing the vicinity of a waste toner discharge port provided in the cleaning device. FIG. 6 is a cross-sectional view of the vicinity of a waste toner discharge port. FIG. 6 is a cross-sectional view of the vicinity of a waste toner discharge port from a direction perpendicular to FIG. 5. FIG. 4 is a cross-sectional view of the vicinity of a toner discharge portion provided with a staying toner scraping unit. It is a perspective view of the agitator simple substance which comprises a staying toner scraping means. It is sectional drawing from a direction perpendicular | vertical to FIG. It is sectional drawing which shows the relationship between the pitch of a conveyance screw, and the space | interval of the comb tooth of an agitator. It is a partial side view which shows another example of the relationship between the pitch of a conveyance screw, and the space | interval of the comb tooth of an agitator. FIG. 3 is a diagram schematically illustrating a toner shape. FIG. 3 is a diagram schematically illustrating the shape of a substantially spherical toner.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional configuration diagram illustrating an example of an image forming apparatus including a cleaning device according to the present invention. The image forming apparatus shown in FIG. 1 is configured as a tandem indirect transfer type color copying apparatus, and includes a copying apparatus main body 100, a paper feed table 200, a scanner (image reading apparatus) 300, an automatic document feeder (ADF). ) 400.

  The copying machine main body 100 is provided with an endless belt-shaped intermediate transfer member 10 at the center. The intermediate transfer member 10 is wound around three support rollers 14, 15, 16 and can be rotated and conveyed clockwise in the figure.

  In the present embodiment, of the three support rollers 14, 15, 16, an intermediate transfer member cleaning device (cleaning) that removes residual toner remaining on the intermediate transfer member 10 after image transfer is provided on the left side of the support roller 16 in the drawing. Means) 17 is provided. Further, four image formations of yellow, magenta, cyan and black are formed on the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15 along the conveyance direction. Means (image forming units) 18 are arranged side by side, and these image forming means 18 constitute a tandem image forming apparatus 20. An exposure device 21 is further provided on the tandem image forming apparatus 20.

  On the other hand, a secondary transfer device (secondary transfer unit) 22 is provided on the side opposite to the tandem image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet. A fixing device 25 for fixing the transferred image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.

  The secondary transfer device 22 described above also has a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a transfer roller or a non-contact charger may be disposed as the secondary transfer device 22, but in this case, it is difficult to provide this sheet conveying function together.

  Further, in the present embodiment, the sheet reversal for reversing the sheet to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. A device 28 is provided.

Next, image formation by the color copying apparatus having the above configuration will be described.
When making a copy using the color copying apparatus having the above-described configuration, first, a document is set on the document table 30 of the automatic document feeder 400 or the automatic document feeder 400 is opened and the document is placed on the contact glass 32 of the scanner 300. Is set, and the automatic document feeder 400 is closed and pressed by it.

  Next, when a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is conveyed by the automatic document feeder 400 and moved onto the contact glass 32, and then the scanner 300 is driven. The first traveling body 33 and the second traveling body 34 travel. On the other hand, when the document is set on the contact glass 32, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34. The reflected light is further reflected by the mirror of the second traveling body 34 and enters the reading sensor 36 through the imaging lens 35. Thereby, the content of the original is read.

  When the start switch is pressed as described above, one of the support rollers 14, 15, and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer member 10 is rotated and conveyed. Is done. Simultaneously with the rotation of the intermediate transfer member 10, the individual image forming means 18 (18Y, 18M, 18C, 18K) rotates the photosensitive member (image carrier) 40 (40Y, 40M, 40C, 40K), Monochromatic images of yellow (Y), magenta (M), cyan (C), and black (K) are formed on the photoreceptor 40, respectively. Then, along with the conveyance of the intermediate transfer member 10, these single color images are sequentially transferred from the photosensitive member 40 to the intermediate transfer member 10 by the action of the transfer charger 62 (62 Y, 62 M, 62 C, 62 K). A composite color image is formed.

  Further, when the start switch is pressed as described above, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and a sheet is fed from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages. It is paid out. The fed sheets are separated one by one by the separation roller 45, introduced into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and then registered. The roller 49 is abutted and stopped. On the other hand, when the manual feed tray 51 is used, the paper feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, and the fed sheets are separated one by one by the separation roller 52 and then manually fed. The paper is introduced into the paper path 53 and is similarly stopped against the registration roller 49.

  Thereafter, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, and the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22. A color image is recorded on the sheet by the transfer by the secondary transfer device 22.

  The sheet after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25. After the transfer image is fixed by applying heat and pressure by the fixing device 25, the switching claw 55 is switched. The paper is discharged by a discharge roller 56 and stacked on a paper discharge tray 57. On the other hand, in the case of double-sided copying, the sheet on which the image is transferred on one side is introduced into the sheet reversing device 28 by the switching of the switching claw 55 and reversed, and then guided again to the transfer position, and the image is also recorded on the back side. Thereafter, the paper is discharged onto a paper discharge tray 57 by a discharge roller 56.

  On the other hand, the intermediate transfer body 10 after the image transfer is prepared by the intermediate transfer body cleaning device 17 to remove the residual toner remaining on the intermediate transfer body 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare the image again.

Here, the registration roller 49 is generally used while being grounded, but it is also possible to apply a bias for removing paper dust from the sheet. For example, a bias is applied using a conductive rubber roller. The surface is a conductive NBR rubber having a diameter of 18 mm and a thickness of 1 mm. The electrical resistance is about 10E9 (10 ⁹ ) Ωcm in terms of the volume resistance of the rubber material, and the applied voltage is a voltage of about −800 V on the toner transfer side (front side) and a voltage of about +200 V on the back side of the paper. Apply. In general, in the intermediate transfer method, it is difficult for paper dust to move to the photoconductor, so that it is not necessary to consider paper dust transfer and may be grounded. A DC bias is applied as the applied voltage, but this may be an AC voltage having a DC offset component in order to charge the sheet more uniformly. Thus, the paper surface after passing through the registration roller 49 to which a bias is applied is slightly charged on the negative side. Therefore, in the transfer from the intermediate transfer body 10 to the sheet, there are cases where the transfer conditions are changed and the transfer conditions are changed as compared with the case where no voltage is applied to the registration roller 49.

  The above-mentioned intermediate transfer member cleaning is generally performed by bringing a rubber blade represented by polyurethane rubber into contact with the belt. This is because an inexpensive and reliable cleaning property can be expected.

  In the present embodiment, as described above, the blade cleaning method is adopted as the cleaning device 17 for the intermediate transfer member 10. However, in this method, when paper dust is caught between the blade and the belt, a cleaning failure occurs. . In the image forming apparatus according to the present embodiment, the transfer paper directly contacts the belt 10 (intermediate transfer member), and thus paper powder cannot be avoided.

  Therefore, as a method for preventing the influence of paper dust and ensuring cleaning properties, the cleaning device 17 in the present embodiment is provided with a paper dust removing member 101 on the upstream side of the blade 103 as shown in FIG. It is configured to prevent. Here, as an example of the paper dust removing member, the brush roller 101 is used. The paper dust is removed by bringing this into contact with the intermediate transfer belt 10. The brush roller 101 may be rotated together with the intermediate transfer belt 10, but it is preferable that the brush roller 101 is driven. In this example, the material of the brush hair is PET resin. The blade 103 and the brush roller 101 are in contact with the same opposing roller 20 via the intermediate transfer belt 10.

  By placing the brush roller 101 upstream of the blade 103, it is possible to remove toner at the same time as removing paper dust, and the effect of reducing the burden of blade cleaning and extending the life of the blade 103 can be expected.

  As described above, since the paper dust removing member 101 for removing the paper dust on the intermediate transfer belt 10 is provided on the upstream side of the cleaning blade 103 in the rotation direction of the intermediate transfer belt 10, It is possible to prevent the deterioration of the cleaning property due to the sandwiching of the powder at a low cost with a simple configuration without impairing the image formation.

  Further, in the image forming apparatus of the present embodiment, since the paper dust removing member 101 is formed by the brush roller, the toner can be collected simultaneously with the paper dust removing, the burden on the blade 103 is lightened, and the life of the blade 103 is extended. be able to.

  In the present embodiment, a cleaning device 41 (FIG. 1) for cleaning the photosensitive drum 40 is also provided. Since the photoconductor cleaning device and the intermediate transfer belt cleaning device have the same configuration, the features of the present invention will be described below using the intermediate transfer belt cleaning device 17 as an example.

  As shown in FIG. 2, in the cleaning device 17, a conveying screw 102 that is a conveying means for discharging the collected waste toner (and paper dust) to the outside of the unit of the cleaning device is disposed. The conveying screw 102 extends in the width direction of the intermediate transfer belt 10 (the axial direction of the brush roller 101), and waste toner (and paper dust) conveyed to the end on one side in the axial direction by the conveying screw 102. Is discharged to the outside of the unit from a discharge port of a toner discharge portion provided at the end, and sent to a waste toner tank (not shown) via a conveyance path (not shown).

  FIG. 3 is a cross-sectional view of the cleaning device 17 in the longitudinal direction (the axial direction of the brush roller 101). As shown in this figure, a protruding portion 105 that protrudes from the casing (housing) 104 to the outside of the unit is provided at a lower portion of one side surface (end surface) of the cleaning device 17. FIG. 4 is a partial perspective view showing the vicinity of the protruding portion 105 where the waste toner discharge port is provided. FIG. 5 is a sectional view along the axial direction of the protruding portion 105 (the axial direction of the conveying screw 102). FIG. 6 is a cross-sectional view in a direction perpendicular to the axis of the protruding portion 105 (the axis of the conveying screw 102). As can be seen from these drawings, the conveying screw 102 is provided with an end portion on one side extending to the inside of the protruding portion 105, and a waste toner discharge port is formed on the lower surface of the end portion of the protruding portion 105. An opening 106 is formed.

  Waste toner and paper dust collected by the cleaning blade 103 and the brush roller 101 in the cleaning device 17 are transported to the right in FIG. 3 by the transport screw 102 and sent into the protruding portion 105. Waste toner, paper dust, and the like sent into the projecting portion 105 are free-dropped from an opening 106 provided on the lower surface of the projecting portion 105, and then are disposed through a transport path such as a tube (not shown). (Not shown).

  Here, in the conventional cleaning device, when the toner is discharged from the waste toner discharge port by free-falling, when the fluidity of the waste toner is lowered, the vicinity of the opening which is the waste toner discharge port In addition, there is a problem that waste toner or the like sticks to the toner, and toner accumulation easily occurs.

  Therefore, in the cleaning device according to the present invention, as described below with reference to FIGS. 7 to 9, a staying toner scraping means for scraping off the staying toner in the vicinity of the opening 106 is provided.

  FIG. 7 is a cross-sectional view (a cross-sectional view along the axial direction of the conveying screw 102) near the toner discharge portion provided with the staying toner scraping means. FIG. 8 is a perspective view of a single agitator constituting the staying toner scraping means. FIG. 9 is a cross-sectional view (a cross-sectional view perpendicular to the axis of the conveying screw 102) of the protruding portion 105 provided with the staying toner scraping means.

  As shown in these drawings, an agitator 120 as a staying toner scraping means swings around a shaft 121 in an opening 106 which is a waste toner discharge port provided in a protruding portion 105 of the cleaning device 17. It is attached as possible. As can be seen from FIG. 9, the shaft 121 that is the rotation center of the agitator 120 is supported in parallel with the shaft 120 a of the conveying screw 102. As can be seen from FIG. 8, the agitator 120 protrudes from the shaft 121 on the opposite side of the shaft 121, the comb tooth portion 122 (first swinging portion) protruding from the shaft 121, and the comb tooth portion 122. It is comprised from the flat plate part 123 (2nd rocking | swiveling part). Further, the comb-tooth portion 122 includes an upright portion 122a that rises straight from the shaft 121 and a bent portion 122b that follows the upright portion. Thereby, the shape of the comb-tooth part 122 seen from the axial direction of the shaft 121 is a "<" shape as shown in FIG. Note that at least the comb teeth 122 of the agitator 120 are formed of a flexible member.

  As can be seen from FIG. 9, the agitator 120 has a wall surface of the opening 106 such that the comb tooth portion 122 is on the upper side (conveying screw 102 side) and the flat plate portion 123 is on the lower side (opening portion 106 side). (In this example, it is arranged at a position close to the one side wall surface) so that the tip of the bent portion 122b of the comb tooth portion 122 can come into contact with the casing wall surface above the opening so that the agitator 120 does not rotate around once. It is supported.

  As shown in FIG. 7, the conveying screw 102 extends in the protruding portion 105, and the blade 102 b contacts the comb tooth portion 122 of the agitator 120 when the screw rotates, so that the agitator 120. Is supported. Here, the blades 102b of the conveying screw 102 are inclined with respect to the shaft 102a (continuously obliquely as shown in FIG. 10), and the comb tooth portion 122 has a gap in the axial direction. Therefore, when the conveying screw 102 rotates, the blade 102b repeats contact and non-contact with the comb tooth portion 122 (a state in which the blade 102b enters the gap between the comb teeth).

  When the blade 102b of the screw contacts the comb tooth 122, the comb tooth 122 is pushed by the blade 102b, and the agitator 120 is rotated clockwise in FIG. As described above, the tip of the bent portion 122b of the comb tooth portion 122 is in contact with the casing wall surface, but since the comb tooth portion 122 is formed of a flexible member, the blade 102b is deformed while the comb tooth portion 122 is deformed. When pushed, the agitator 120 rotates. Then, as the screw rotates, when the blade 102b enters the gap between the comb teeth and the pressing of the comb tooth portion 122 is released, the deformed comb tooth portion 122 tries to return to its original state by its own elastic force, Pushing the casing wall surface causes the agitator 120 to rotate counterclockwise in FIG.

  In this way, when the conveying screw 102 rotates, the pressing and releasing of the comb teeth 122 by the blades 102b are repeated, and the agitator 120 swings as indicated by a double-headed arrow in FIG. ). As the agitator 120 repeatedly swings, the flat plate portion 123 protruding from the shaft 121 reciprocates in the vicinity of the opening portion 106, so that even when the fluidity of waste toner or the like is reduced, the opening portion 106. The toner staying in the vicinity is scraped by the agitator 120 (the flat plate portion 123), so that toner accumulation can be prevented in advance. Thus, the waste toner can be discharged out of the cleaning device unit without the waste toner being fixed to the discharge port.

  Here, as shown in FIG. 10, when the pitch of the conveying screw 102 (pitch of the coil blade 102b) is “p”, the interval (pitch) of the comb teeth 122 of the agitator 120 is “k × p” ( It is preferable that k is a coefficient. As an example of the coefficient k, k = 1, k = 0.5, etc. can be set. When k = 1, the comb teeth 122 of the agitator 120 are all in contact with the coil of the conveying screw 102 at the same time. When k = 0.5, the comb teeth 122 of the agitator 120 are separated by one tooth. At the same time, the coil of the conveying screw 102 is brought into contact with the agitator 120 and a large rotational force is obtained.

  Further, N and M may be different integers (N ≠ M), and k = N / M. For example, N = 2, M = 3, etc. are possible. In this case, a certain contact portion, its N-th coil, and M-th comb teeth are in contact at the same time.

  As shown in FIG. 11, when the pitch of the comb teeth 122 is “k × p + α”, the contact timing between the conveying screw 102 and each comb tooth 122 of the agitator 120 is the interval between the comb teeth by α. By shifting, the contact timing is shifted, and the number of comb teeth contacting the screw at the same time is smaller than that in the case of k × p. Thereby, the shock at the time of contact with the conveying screw 102 and the agitator 120 is reduced, the generated sound is reduced, and the soundproofing effect is obtained.

  The comb teeth of the agitator are not limited to the flat plate shape as described above, but may be any shape that can come into contact with the conveying screw, such as a rod shape, a cylindrical shape, or a conical shape.

Further, the intervals between the comb teeth of the agitator are not limited to equal intervals, and may be random. Also in this case, since the conveying screw and each tooth are in contact with each other at random timing, it is possible to prevent generation of a loud sound due to many teeth contacting at once.
Furthermore, by forming the agitator 120 from a conductive material and dropping it to the ground, frictional charging can be prevented and toner discharge performance can be improved.

  As described above, the cleaning device 17 that is a cleaning unit for the intermediate transfer belt is provided with the staying toner scraping unit that scrapes off the staying toner near the opening that is the waste toner discharge port. Also in the cleaning device 41 as the cleaning means, the staying toner scraping means is provided in the vicinity of the opening for discharging the collected waste toner, and toner accumulation in the opening is generated in the same manner as in the cleaning device 17. Can be prevented. Thus, the waste toner can be discharged out of the cleaning device unit without the waste toner being fixed to the discharge port. In the case of the photoconductor cleaning device 41, waste toner discharged out of the unit can be collected in a waste toner tank or sent to a developing device for reuse.

  Here, the toner used in this image forming apparatus is a small diameter, narrow particle size distribution and spheroidization (sphericalization) with a polymerized toner in order to cope with recent rapid colorization and accompanying high image quality. ) Is becoming mainstream. The distribution of toner with a small diameter and a narrow particle diameter is advantageous for high-resolution development, and the spheroidization (true sphere) is advantageous for transfer efficiency, and thereby the image quality such as the sharpness of the toner image is remarkably improved.

  However, reducing the particle size of the toner increases the specific surface area and increases the adhesion force of the toner per unit weight to the surface of the image carrier, which makes it difficult to clean the surface of the image carrier. Further, the reduction in the toner particle size deteriorates the fluidity of the toner and requires a larger amount of additive, which may cause chipping and abrasion of the cleaning blade, local streak scratches on the surface of the image carrier, and the like. It is known to be.

  In addition, when the sphericity of the toner is increased, the above-described blade counter contact method generally used in the related art increases the amount of toner passing through the blade, so that it is necessary to increase the contact pressure more than before. Increasing the pressure reduces the margin against edge chipping due to the local shearing force of the blade.

Next, the toner suitably used in the image forming apparatus of the present invention will be described.
In order to reproduce minute dots of 600 dpi or more, the toner preferably has a volume average particle diameter of 3 to 8 μm. The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is preferably in the range of 1.00 to 1.40. The closer (Dv / Dn) is to 1.00, the sharper the particle size distribution. With such a toner having a small particle size and a narrow particle size distribution, the toner charge amount distribution is uniform, a high-quality image with little background fogging can be obtained, and the electrostatic transfer method has a high transfer rate. can do.

The toner shape factor SF-1 is preferably in the range of 100 to 180, and the shape factor SF-2 is preferably in the range of 100 to 180.
FIG. 12 is a diagram schematically illustrating the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) 2 / AREA} × (100π / 4) Expression (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.

The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) 2 / AREA} × (100π / 4) Expression (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.

  Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.

  When the shape of the toner is close to a spherical shape, the contact state between the toner and the toner or the toner and the photoconductor becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases, and the toner and the photoconductor The attraction force becomes weaker and the transfer rate becomes higher. If either of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.

The toner suitably used in the image forming apparatus of the present invention includes a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. A toner obtained by crosslinking and / or elongation reaction in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.
(polyester)

The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight is 10,000 to 400,000, preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ); Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

  The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).

  In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the gloss when used in the full-color image forming apparatus 100 are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond.

  The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.

  The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.

  In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

[Colorant]
As the colorant, all known dyes and pigments can be used. 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, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol 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, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, 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, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

[Charge control agent]
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSYVP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (manufactured by Nippon Carlit) ), Copper phthalocyanine, perylene, quinacridone, azo face And other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

[Release agent]
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .

  The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

[External additive]
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × 10 −3 to 2 μm, and particularly preferably 5 × 10 −3 to 0.5 μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle size of 5 × 10-2 μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed, a fluidity-imparting agent is not detached from the toner, a good image quality that does not cause fireflies and the like is obtained, and a reduction in residual toner is further achieved. .

  Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

  Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.

[Toner Production Method]
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, 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 can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

  The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
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 salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

  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 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

  The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao), SGP (manufactured by Soken), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).

In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.
As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer 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 acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, 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, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.

  Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

The shape of the toner suitably used in the image forming apparatus according to the present invention is a substantially spherical shape, and can be represented by the following shape rule.
FIG. 13 is a diagram schematically illustrating the shape of the toner. In FIG. 13, when a substantially spherical toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner of the present invention has a major axis and a minor axis. Ratio (r2 / r1) (see FIG. 13 (b)) is 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) (see FIG. 13 (c)) is 0.7 to It is preferable to be in the range of 1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high-quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.

Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.
As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this. For example, an appropriate form can be adopted as the configuration of the cleaning device within the scope of the present invention. The shape and pitch of the conveying screw are arbitrary. Further, the configuration, material, and the like of the agitator as the staying toner scraping means can adopt an appropriate form within the scope of the present invention. The location of the cleaning device with respect to the photosensitive member as the image carrier or the intermediate transfer member is also arbitrary. It is also possible to use a belt-like photoreceptor or an intermediate transfer drum.

  The configuration of the image forming unit of the image forming apparatus is also arbitrary, and the arrangement order of the color process cartridges in the tandem type is arbitrary. In addition to the tandem type, a configuration in which a plurality of developing devices are arranged around a single photosensitive member, or a configuration using a revolver type developing device is also possible. The present invention can also be applied to a full color machine using three color toners, a multicolor machine using two color toners, or a monochrome apparatus. Of course, the image forming apparatus is not limited to a copying machine, but may be a printer, a facsimile machine, or a multifunction machine having a plurality of functions.

10 Intermediate transfer member 17 Cleaning device (Intermediate transfer member cleaning device)
18 Image forming unit 20 Opposing roller 40 Photoconductor 41 Cleaning device (photoconductor cleaning device)
DESCRIPTION OF SYMBOLS 100 Copying apparatus main body 101 Brush roller 102 Conveying screw 103 Cleaning blade 104 Casing (cleaning apparatus housing)
105 Projection part 106 Opening part (waste toner discharge port)
120 Agitator (Restoring means for staying toner)
121 Shaft (Agitator shaft)
122 Comb teeth (first swing part)
123 Flat plate part (second swing part)
200 Paper feed table 300 Scanner (image reading device)
400 Automatic document feeder (ADF)

JP 2004-361480 A

Claims (15)

In a cleaning apparatus having a removing means for removing toner on an image carrier on which a toner image is carried on a surface, and a conveying screw for conveying the toner removed by the removing means toward a toner discharge portion,
A staying toner scraping means which is provided in the toner discharge portion and is swung by the conveying screw ;
A first swinging portion that swings in contact with the conveying screw; and a second swinging portion that swings in conjunction with the swinging of the first swinging portion. A cleaning device comprising an agitator comprising: The cleaning apparatus according to claim 1 , wherein the agitator has a rotation shaft, and the first swinging portion and the second swinging portion rotate while being supported by the rotation shaft. The cleaning apparatus according to claim 2 , wherein the rotation shaft is disposed in parallel with an axis of the conveying screw. The said 1st rocking | fluctuation part is provided in the comb-tooth shape which consists of a some member arrange | positioned at intervals along the said rotating shaft direction, The Claim 2 or 3 characterized by the above-mentioned. Cleaning device. When the coil pitch of the conveying screw is p, the pitch of the comb teeth of the first oscillating portion is k × p (k is a coefficient).
The cleaning apparatus according to claim 4 , wherein: When the coil pitch of the conveying screw is p, the pitch of the comb teeth of the first oscillating portion is k × p + α (k is a coefficient).
The cleaning apparatus according to claim 4 , wherein: The conveying screw and the agitator are accommodated in a casing of the cleaning device, and the toner discharge portion is provided in a part of the casing.
The first oscillating part is made of a flexible material, and the first oscillating part contacts the casing when oscillating in contact with the conveying screw . 5. The cleaning device according to any one of 4 above. The toner discharge portion and which are located below the conveying screw, a cleaning device according to any one of claims 1-7.   The cleaning device according to claim 1, wherein the staying toner scraping means is made of a conductive material. An image forming apparatus comprising: a cleaning device according to any one of claims 1-9. The image forming apparatus according to claim 10 , wherein the cleaning device is a device for cleaning an intermediate transfer member. The image forming apparatus according to claim 10 , wherein the cleaning device is a device that cleans a photosensitive member. The volume average particle size is 3 to 8 [μm], the value obtained by dividing the volume average particle size by the number average particle size is in the range of 1.00 to 1.40, and the shape factor SF-2 is 100 to 190. characterized by using the toner is, the image forming apparatus according to any one of claims 10-12. As the toner, at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. The image forming apparatus according to claim 13 , wherein what is obtained by both reactions is used. As the toner, a value obtained by dividing the uniaxial axis r2 of the toner particle by the major axis r1 is in the range of 0.5 to 1.0, and the thickness r3 of the toner particle (where r1 ≧ r2 ≧ r3) is determined as the uniaxial axis r2. in dividing the value it is characterized by using a, which is in the range of 0.7 to 1.0, the image forming apparatus according to claim 13 or 14.

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