JP2011197107A - Process cartridge and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus having a long service life, by combining an electrophotographic photoreceptor and a cleaning means, including a cleaning blade.SOLUTION: The image forming apparatus includes: an electrophotographic photoreceptor 10, having at least a photosensitive layer on a conductive substrate and containing fluororesin particles and a binding resin including a structure unit (A); and a cleaning blade 72, comprising a laminated body of a first layer in contact with the electrophotographic photoreceptor 10 and a second layer that is not in contact with the electrophotographic photoreceptor 10, wherein the type-A durometer hardness of the first layer is higher than that of the second layer and is ≥A77 and ≤A85, and the rebound resilience at 23° of the second layer is ≥35% and ≤45% for the cleaning balde 72.

Description

  The present invention relates to a process cartridge and an image forming apparatus.

  In a conventional electrophotographic image forming apparatus, a toner image formed on the surface of an electrophotographic photosensitive member is transferred to a recording medium through processes of charging, exposure, development, and transfer.

  For example, Patent Document 1 discloses a method for reducing the surface energy of a surface layer of a photoreceptor by dispersing fluorine-based resin particles in the surface layer, and Patent Document 2 discloses a conductive metal particle or a surface layer. A method of containing a fluororesin has been proposed.

Patent Document 3 proposes a configuration in which an inorganic fine particle is contained in the outermost surface layer of the photoreceptor, and a polyurethane blade having a rebound resilience of 50% or less and a Young's modulus of 55 kg / cm ² or less is used as a cleaning blade.
In Patent Document 4, inorganic fine particles are contained in the outermost surface layer of the photoreceptor, cleaning is performed with a hardness of 65 or more and permanent elongation of 2% or less, or a rebound resilience of 50% or less, and a 300% modulus of 130 kg / cm ^2. A configuration using a polyurethane blade is proposed.

JP-A-63-221355 JP-A-6-250460 JP-A-8-254841 JP-A-8-320640

  An object of the present invention is to provide an image forming apparatus having a longer life as compared with a case where an electrophotographic photosensitive member having the following configuration and a cleaning unit having a cleaning blade having the following configuration are not combined.

The above problem is solved by the following means. That is,
The invention according to claim 1
An electrophotographic photosensitive member having at least a photosensitive layer on a conductive substrate, the outermost surface layer containing fluororesin particles and a binder resin containing the following structural unit (A);
Charging means for charging the electrophotographic photoreceptor;
Electrostatic latent image forming means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image; and
Toner image forming means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring a toner image formed on the electrophotographic photosensitive member to a transfer target;
A cleaning blade configured by cleaning a surface of the electrophotographic photosensitive member and including a laminate of a first layer in contact with the electrophotographic photosensitive member and a second layer not in contact with the electrophotographic photosensitive member, A cleaning means having a cleaning blade in which the hardness of one type A durometer is higher than that of the second layer and is A77 or more and A85 or less, and the rebound resilience at 23 ° C. of the second layer is 35% or more and 45% or less. When,
An image forming apparatus.

The invention according to claim 2
The binder resin containing the structural unit (A) is a binder resin represented by the following structural formulas (A1) to (A2) (however, in the following structural formula (A2), m: n represents a copolymerization ratio; 2. The image forming apparatus according to claim 1, wherein m: n = 95: 5 to 5:95.

The invention according to claim 3
The image forming apparatus according to claim 2, wherein the binder resin represented by the structural formulas (A1) to (A2) has a copolymerization ratio m: n = 10: 90 to 40:60.

The invention according to claim 4
An electrophotographic photosensitive member having at least a photosensitive layer on a conductive substrate, the outermost surface layer containing fluororesin particles and a binder resin containing the following structural unit (A);
A cleaning blade configured by cleaning a surface of the electrophotographic photosensitive member and including a laminate of a first layer in contact with the electrophotographic photosensitive member and a second layer not in contact with the electrophotographic photosensitive member, Cleaning having a cleaning blade in which the hardness of one type A durometer is higher than that of the second layer and is A77 or more and A85 or less, and the rebound resilience at 23 ° C. of the second layer is 35% or more and 45% or less. Means,
With
A process cartridge that is detachable from the image forming apparatus.

The invention according to claim 5
The binder resin containing the structural unit (A) is a binder resin represented by the following structural formulas (A1) to (A2) (however, in the following structural formula (A2), m: n represents a copolymerization ratio; 5. The process cartridge according to claim 4, wherein m: n = 95: 5 to 5:95.

The invention according to claim 6
6. The process cartridge according to claim 5, wherein the binder resin represented by the structural formulas (A1) to (A2) exhibits a copolymerization ratio m: n = 10: 90 to 40:60.

According to the first aspect of the present invention, there is provided an image forming apparatus having a longer life as compared with the case where the electrophotographic photosensitive member having the above configuration and the cleaning means having the cleaning blade having the above configuration are not combined.
According to the second aspect of the present invention, image formation with a longer lifetime than the case where the binder resins represented by the structural formulas (A1) to (A2) are not applied as the binder resin containing the structural unit (A). An apparatus is provided.
According to the third aspect of the invention, as the binder resin represented by the structural formulas (A1) to (A2), an image having a long lifetime as compared with a case where a resin having a copolymerization ratio m: n outside the above range is applied. A forming apparatus is provided.
According to the fourth aspect of the present invention, there is provided a process cartridge having a longer life as compared with the case where the electrophotographic photosensitive member having the above configuration and the cleaning means having the cleaning blade having the above configuration are not combined.
According to the fifth aspect of the present invention, the process cartridge has a longer life as compared with the case where the binder resin represented by the structural formulas (A1) to (A2) is not applied as the binder resin including the structural unit (A). Is provided.
According to the invention of claim 6, a process having a long life as compared with the case where a binder resin represented by structural formulas (A1) to (A2) having a copolymerization ratio m: n outside the above range is applied. A cartridge is provided.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other this embodiment. 1 is a schematic cross-sectional view showing an electrophotographic photosensitive member according to the present embodiment. It is a schematic sectional drawing which shows the electrophotographic photoreceptor which concerns on this other embodiment. It is a schematic diagram which shows the cleaning blade periphery which concerns on this embodiment.

  Embodiments that are examples of the present invention will be described below.

The image forming apparatus according to this embodiment includes an electrophotographic photosensitive member having at least a photosensitive layer on a conductive substrate, and the outermost surface layer including fluororesin particles and a binder resin including the following structural unit (A). When,
Charging means for charging the electrophotographic photoreceptor;
Electrostatic latent image forming means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image; and
Toner image forming means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring a toner image formed on the electrophotographic photosensitive member to a transfer target;
A cleaning blade configured by cleaning a surface of the electrophotographic photosensitive member and including a laminate of a first layer in contact with the electrophotographic photosensitive member and a second layer not in contact with the electrophotographic photosensitive member, A cleaning means having a cleaning blade in which the hardness of one type A durometer is higher than that of the second layer and is A77 or more and A85 or less, and the rebound resilience at 23 ° C. of the second layer is 35% or more and 45% or less. When,
An image forming apparatus.

In the image forming apparatus according to the present embodiment, the above-described configuration results in an image forming apparatus having a long lifetime. This is because the occurrence of scratches, wear and uneven wear on the electrophotographic photosensitive member, and the occurrence of chipping and wrinkling of the cleaning blade are both suppressed, and it is considered that both of these are maintained over a long period of time. . And this reason is estimated as shown below.
First, when a binder resin containing a biphenyl copolymer component such as the structural unit (A) is applied as a constituent material of the outermost surface layer of the electrophotographic photosensitive member, an electrophotographic photosensitive member having an outermost surface layer with high strength and high resilience is obtained. It is considered to be. In addition to this, it is considered that by including fluororesin particles in the outermost surface layer of the electrophotographic photosensitive member, an electrophotographic photosensitive member having an outermost surface layer having a low friction coefficient, high strength and high resilience is considered.

The hardness of the type A duprometer of the electrophotographic photosensitive member and the first layer in contact with the electrophotographic photosensitive member is higher than that of the second layer and in the above range, and the repulsion of the second layer at 23 ° C. By combining with a cleaning blade having elasticity within the above range, the electrophotographic photosensitive member having the outermost surface layer having the above low friction coefficient and high strength and high resilience can be further cleaned by the cleaning blade with low friction. Therefore, it is considered that the occurrence of scratches, wear and uneven wear of the electrophotographic photosensitive member is further suppressed and these are maintained.
Further, since cleaning is performed with a cleaning blade with low friction, the posture of the cleaning blade can be easily maintained, and the occurrence of chipping or wobbling of the cleaning blade can be suppressed and these can be maintained.

  For this reason, the image forming apparatus according to the present embodiment is considered to be an image forming apparatus having a long lifetime by adopting the above configuration. A process cartridge including the electrophotographic photosensitive member and a cleaning unit having the cleaning blade is considered to be an image forming apparatus having a long life.

Hereinafter, the present embodiment will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.

  As shown in FIG. 1, the image forming apparatus 101 according to the present embodiment includes, for example, an electrophotographic photosensitive member 10 that rotates clockwise as indicated by an arrow a, A charging device 20 (an example of a charging unit) that is provided relative to the photographic photosensitive member 10 and charges the surface of the electrophotographic photosensitive member 10, and the surface of the electrophotographic photosensitive member 10 charged by the charging device 20 is exposed to light. An exposure device 30 (an example of an electrostatic latent image forming unit) that forms an electrostatic latent image, and a toner contained in a developer is attached to the electrostatic latent image formed by the exposure device 30 to form an electrophotographic photosensitive member 10. A developing device 40 (an example of a developing unit) that forms a toner image on the surface and a toner image formed on the surface of the electrophotographic photoreceptor 10 while traveling in the direction indicated by the arrow b while contacting the electrophotographic photoreceptor 10 Belt-like transfer And between transfer member 50, and a cleaning device 70 for cleaning the surface of the electrophotographic photosensitive member 10 (an example of a cleaning unit).

  The charging device 20, the exposure device 30, the developing device 40, the intermediate transfer member 50, the lubricant supply device 60, and the cleaning device 70 are arranged in a clockwise direction on the circumference surrounding the electrophotographic photosensitive member 10. In this embodiment, a mode in which the lubricant supply device 60 is disposed inside the cleaning device 70 will be described. However, the present invention is not limited to this, and the lubricant supply device 60 is disposed separately from the cleaning device 70. It may be in the form.

  The intermediate transfer member 50 is held from the inside while being tensioned by the support rollers 50A and 50B, the back roller 50C, and the drive roller 50D, and is driven in the direction of the arrow b as the drive roller 50D rotates. At a position facing the electrophotographic photosensitive member 10 inside the intermediate transfer member 50, the intermediate transfer member 50 is charged to a polarity different from the charging polarity of the toner, and the electrophotographic photosensitive member 10 is placed on the outer surface of the intermediate transfer member 50. A primary transfer device 51 for adsorbing the upper toner is provided. On the outer side below the intermediate transfer member 50, the recording paper P (an example of a recording medium) is charged to a polarity different from the charged polarity of the toner, and the toner image formed on the intermediate transfer member 50 is placed on the recording paper P. A secondary transfer device 52 for transferring is provided to face the back roller 50C. These members for transferring the toner image formed on the electrophotographic photosensitive member 10 to the recording paper P correspond to an example of a transfer unit.

  Below the intermediate transfer member 50, a recording paper supply device 53 that supplies the recording paper P to the secondary transfer device 52 and a recording paper P on which the toner image is formed in the secondary transfer device 52 are conveyed. A fixing device 80 for fixing the toner image is provided.

  The recording paper supply device 53 includes a pair of transport rollers 53A and a guide slope 53B that guides the recording paper P transported by the transport rollers 53A toward the secondary transfer device 52. On the other hand, the fixing device 80 includes a fixing roller 81 that is a pair of heat rollers for fixing the toner image by heating and pressing the recording paper P onto which the toner image has been transferred by the secondary transfer device 52, and a fixing roller. And a conveyance conveyor 82 that conveys the recording paper P toward 81.

  The recording paper P is conveyed in the direction indicated by the arrow c by the recording paper supply device 53, the secondary transfer device 52, and the fixing device 80.

  The intermediate transfer member 50 is further provided with an intermediate transfer member cleaning device 54 having a cleaning blade for removing the toner remaining on the intermediate transfer member 50 after the toner image is transferred to the recording paper P in the secondary transfer device 52. Yes.

  Details of main components in the image forming apparatus 101 according to the present embodiment will be described below.

(Electrophotographic photoreceptor)
FIG. 3 is a schematic cross-sectional view showing the electrophotographic photoreceptor according to this embodiment. FIG. 4 is a schematic cross-sectional view showing an electrophotographic photoreceptor according to another embodiment.

An electrophotographic photoreceptor 10A shown in FIG. 3 is a so-called function-separated photoreceptor (or a laminated photoreceptor), and an undercoat layer 1 is provided on a conductive substrate 4, on which a charge generation layer 2 and It has a structure in which the charge transport layer 3 is sequentially formed. In the electrophotographic photoreceptor 10A, the charge generation layer 2 and the charge transport layer 3 constitute a photosensitive layer.
In the electrophotographic photoreceptor 10 </ b> A shown in FIG. 3, the charge transport layer 3 is the outermost surface layer disposed on the side farthest from the conductive substrate 4.

An electrophotographic photoreceptor 10B shown in FIG. 4 contains a charge generation material and a charge transport material in the same layer (single-layer type photosensitive layer 6 (charge generation / charge transport layer)).
Specifically, the electrophotographic photoreceptor 10B shown in FIG. 4 has a structure in which the undercoat layer 1 is provided on the conductive substrate 4 and the single-layer type photosensitive layer 6 is formed thereon. .
In the electrophotographic photoreceptor 10 </ b> B shown in FIG. 4, the single-layer type photosensitive layer 6 is the outermost surface layer disposed on the side farthest from the conductive substrate 4.

  In the electrophotographic photoreceptor shown in FIGS. 3 to 4, the undercoat layer 1 may or may not be provided.

  Hereinafter, each element in the electrophotographic photosensitive member will be described. Hereinafter, description will be made with the reference numerals omitted.

First, the conductive substrate will be described. “Conductivity” means, for example, a volume resistivity of 10 ¹³ Ω · cm or less.
Any conductive substrate may be used as long as it is conventionally used. For example, thin films (eg, metals such as aluminum, nickel, chromium, stainless steel, and films of aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, indium tin oxide (ITO), etc.) And a plastic film coated or impregnated with a conductivity-imparting agent, a plastic film coated or impregnated with a conductivity-imparting agent, and the like. The shape of the conductive substrate is not limited to a cylindrical shape, and may be a sheet shape or a plate shape.

  When a metal pipe is used as the conductive substrate, the surface may be left as it is, and treatments such as mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, and wet honing have been performed in advance. Also good.

Next, the undercoat layer will be described.
The undercoat layer is provided as necessary for the purpose of preventing light reflection on the surface of the conductive substrate and preventing inflow of unnecessary carriers from the conductive substrate to the photosensitive layer.

The undercoat layer includes, for example, a binder resin and, if necessary, other additives.
As the binder resin contained in the undercoat layer, acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, Known polymer resin compounds such as polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin, and charge transporting group Examples thereof include charge transporting resins having a conductive resin such as polyaniline. Among these, resins that are insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used.

The undercoat layer may contain a metal compound such as a silicon compound, an organic zirconium compound, an organic titanium compound, or an organic aluminum compound.
The ratio between the metal compound and the binder resin is not particularly limited, and is preferably set within a range in which desired electrophotographic photoreceptor characteristics can be obtained.

  Resin particles may be added to the undercoat layer in order to adjust the surface roughness. Examples of the resin particles include silicone resin particles and cross-linked polymethyl methacrylate (PMMA) resin particles. The surface may be polished after forming the undercoat layer for adjusting the surface roughness. As a polishing method, buffing, sandblasting, wet honing, grinding, or the like is used.

Here, the structure of the undercoat layer is particularly preferably a structure containing at least a binder resin and conductive particles. The conductivity means that the volume resistivity is less than 10 ⁷ Ω · cm, for example.
Examples of the conductive particles include metal particles (particles such as aluminum, copper, nickel, and silver), conductive metal oxide particles (particles such as antimony oxide, indium oxide, tin oxide, and zinc oxide), and conductive substance particles. (Carbon fiber, carbon black, particles of graphite powder) and the like. Among these, conductive metal oxide particles are preferable. You may mix and use 2 or more types of electroconductive particle.
In addition, the conductive particles may be subjected to a surface treatment with a hydrophobizing agent (for example, a coupling agent) or the like to adjust the resistance.
For example, the content of the conductive particles is preferably 10% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 80% by mass or less with respect to the binder resin.

  In forming the undercoat layer, an undercoat layer forming coating solution in which the above components are added to a solvent is used. In addition, as a method of dispersing particles in the coating solution for forming the undercoat layer, a media disperser such as a ball mill, a vibration ball mill, an attritor, a sand mill, a horizontal sand mill, an agitator, an ultrasonic disperser, a roll mill, a high-pressure homogenizer, etc. Medialess dispersers are used. Here, examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high-pressure state, and a penetration method in which a fine flow path is dispersed in a high-pressure state. .

  Examples of the method for applying the coating solution for forming the undercoat layer onto the conductive substrate include dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, and curtain coating. It is done.

  The thickness of the undercoat layer is preferably 15 μm or more, and more preferably 20 μm or more and 50 μm or less.

  Here, although not shown, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer. As the binder resin used for the intermediate layer, acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl In addition to polymer resins such as acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, zirconium, titanium, aluminum, manganese, silicon atom, etc. An organometallic compound containing These compounds may be used alone or as a mixture or polycondensate of a plurality of compounds. Among these, an organometallic compound containing zirconium or silicon is preferable.

  In forming the intermediate layer, a coating solution for forming an intermediate layer in which the above components are added to a solvent is used. As the coating method for forming the intermediate layer, usual methods such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, and a curtain coating method are used.

  The thickness of the intermediate layer is preferably set to a film thickness range of 0.1 μm or more and 3 μm or less, for example. Further, this intermediate layer may be used as an undercoat layer.

Next, the charge generation layer will be described.
The charge generation layer includes, for example, a charge generation material and a binder resin. Examples of such charge generating materials include phthalocyanine pigments such as metal-free phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, dichlorotin phthalocyanine, and titanyl phthalocyanine, and in particular, a Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-rays. A chlorogallium phthalocyanine crystal having strong diffraction peaks at least at 7.4 °, 16.6 °, 25.5 ° and 28.3 °, a Bragg angle (2θ ± 0.2 °) to CuKα characteristic X-ray of at least 7 Metal-free phthalocyanine crystals having strong diffraction peaks at .7 °, 9.3 °, 16.9 °, 17.5 °, 22.4 °, and 28.8 °, Bragg angle (2θ ± 0) with respect to CuKα characteristic X-rays .2 °) at least 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 ° Hydroxygallium phthalocyanine crystals having strong diffraction peaks at 25.1 ° and 28.3 °, Bragg angles (2θ ± 0.2 °) with respect to CuKα characteristic X-rays of at least 9.6 °, 24.1 ° and 27.2 A titanyl phthalocyanine crystal having a strong diffraction peak at 0 ° can be mentioned. In addition, examples of the charge generation material include quinone pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, anthrone pigments, quinacridone pigments, and the like. These charge generation materials may be used alone or in combination of two or more.

Examples of the binder resin constituting the charge generation layer include polycarbonate resin such as bisphenol A type or bisphenol Z type, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene. Copolymer resin, acrylonitrile-butadiene copolymer, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride Examples thereof include resins, silicone resins, phenol-formaldehyde resins, polyacrylamide resins, polyamide resins, poly-N-vinylcarbazole resins. These binder resins may be used alone or in combination of two or more.
The mixing ratio of the charge generating material and the binder resin is desirably in the range of 10: 1 to 1:10.

When forming the charge generation layer, a coating solution for forming a charge generation layer in which the above components are added to a solvent is used.
As a method for dispersing particles (for example, electrification generating material) in the coating solution for forming the charge generation layer, a media disperser such as a ball mill, a vibration ball mill, an attritor, a sand mill, a horizontal sand mill, a stirring, an ultrasonic disperser, a roll mill Medialess dispersers such as high-pressure homogenizers are used. Examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high-pressure state, and a penetration method in which a fine flow path is dispersed in a high-pressure state.

  Examples of the method for applying the charge generation layer forming coating liquid on the undercoat layer include dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, and curtain coating. It is done.

  The thickness of the charge generation layer is desirably set in the range of 0.01 μm to 5 μm, more desirably 0.05 μm to 2.0 μm.

Next, the charge transport layer will be described.
The charge transport layer includes, for example, a charge transport material, a binder resin containing the structural unit (A), and fluororesin particles.

  Examples of the charge transport material include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [ Pyrazoline derivatives such as pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, N, N′-bis (3,4-dimethylphenyl) biphenyl- Aromatic tertiary amino compounds such as 4-amine, tri (p-methylphenyl) aminyl-4-amine, dibenzylaniline, N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine Aromatic tertiary diamino compounds such as 3- (4'-dimethylaminophenyl) -5,6-di- (4'-methoxyphenyl) -1,2,4 1,2,4-triazine derivatives such as triazine, hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2,3- Benzofuran derivatives such as di (p-methoxyphenyl) benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly -Hole transport materials such as -N-vinylcarbazole and its derivatives, quinone compounds such as chloranil and broanthraquinone, tetraanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7 -Fluorenone such as tetranitro-9-fluorenone Examples thereof include an electron transport material such as a compound, a xanthone compound, and a thiophene compound, and a polymer having a group consisting of the above-described compounds in a main chain or a side chain. These charge transport materials may be used alone or in combination of two or more.

  The binder resin containing the structural unit (A) is not particularly limited as long as it contains the structural unit (A). For example, the binder resin is a copolymer of the structural unit (A) and another structural unit. Biphenyl copolymerization type polycarbonate resin is mentioned.

  Other structural units include polycarbonate resin such as bisphenol A type, bisphenol C type or bisphenol Z type, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, polyvinyl formal Examples thereof include resins, polysulfone resins, silicone resins, polyacrylamide resins, polyamide resins and the like. Among these, polycarbonate resin such as bisphenol C type or bisphenol Z type is desirable.

  In the biphenyl copolymer polycarbonate resin, the copolymerization ratio (corresponding to the m: n ratio in the following specific examples) of the structural unit (A) and other structural units is, for example, m: n = 95: 5 to 5: The range is preferably 95, preferably 50:50 to 5:95, and more preferably 30:70 to 10:90.

  Specific examples of the binder resin containing the structural unit (A) include, but are not limited to, the following.

  Among the binder resins containing the structural unit (A), from the viewpoint of extending the life of the image forming apparatus, the binder resins represented by the structural formulas (A1) to (A3) (however, the structural formulas (A1) to In (A3), m: n represents a copolymerization ratio, and m: n is preferably in the range of 95: 5 to 5:95. In particular, the above structural formulas (A1) to (A3) The binder resin represented by the formula (1) preferably has a copolymerization ratio m: n = 10: 90 to 40:60, more preferably a copolymerization ratio m: n = 15: 85 to 30:70). There should be. Among the binder resins represented by the structural formulas (A1) to (A3), the binder resins represented by the structural formulas (A1) to (A2) are preferable.

  Note that other binder resins than the binder resin containing the structural unit (A) may be used as long as the function is not impaired. Examples of the other binder resin include polycarbonate resin such as bisphenol A type or bisphenol Z type, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene copolymer. Resin, acrylonitrile-butadiene copolymer resin, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride resin, Insulating resins such as silicone resin, phenol-formaldehyde resin, polyacrylamide resin, polyamide resin, chlorinated rubber, and polyvinylcarbazole, polyvinylanthracene, polyvinyl chloride Organic photoconductive polymers such as Rupiren like. These binder resins may be used alone or in combination of two or more.

Here, the binder resin containing the structural unit (A) is desirably 10% by mass or more and 90% by mass or less, and more desirably 30% by mass or more and 90% by mass or less with respect to the total solid content of the outermost surface layer. More preferably, it is 50 mass% or more and 90 mass% or less.
Also. The blending ratio of the charge transporting material and the binder resin (binder resin containing the structural unit (A) + other binder resin) is preferably 10: 1 to 1: 5.

  Examples of the fluororesin particles include a tetrafluoroethylene resin, a trifluoroethylene chloride resin, a hexafluoropropylene resin, a vinyl fluoride resin, a vinylidene fluoride resin, a difluorodiethylene chloride resin, and copolymers thereof. It is desirable to select one or more of the particles. Among these, as the fluororesin particles, tetrafluoroethylene resin particles and vinylidene fluoride resin particles are particularly desirable.

The primary particle size of the fluororesin particles is preferably 0.05 μm or more and 1 μm or less, and preferably 0.1 μm or more and 0.5 μm or less.
The primary particles are obtained by obtaining a sample piece from the outermost surface layer of the electrophotographic photosensitive member, and observing this with a SEM (scanning electron microscope), for example, at a magnification of 5000 times or more. The diameter is measured and this is taken as the average value obtained for 50 particles. Note that a JSM-6700F manufactured by JEOL Ltd. is used as the SEM, and a secondary electron image with an acceleration voltage of 5 kV is observed.

  The fluororesin particles are preferably used in combination with a fluorine-based graft polymer as a dispersant. The amount of the dispersant is not particularly limited, but is preferably 0.1% by mass or more and 10% by mass or less with respect to the fluororesin particles.

  The content of the fluororesin particles is desirably 2% by mass or more and 15% by mass or less, and more desirably 4% by mass or more and 12% by mass or less with respect to the total solid content of the charge transport layer (outermost surface layer). More preferably, it is 6 mass% or more and 10 mass% or less.

Here, the charge transport layer may further contain a fluorine-modified silicone oil as necessary. Examples of the fluorine-modified silicone oil include fluorine-modified silicone oil in which a part or all of the substituents of the organopolysiloxane are substituted with a fluoroalkyl group (for example, a fluoroalkyl group having 1 to 10 carbon atoms).
The content of the fluorine-modified silicone oil is, for example, preferably in the range of 0.1 ppm to 1000 ppm, and preferably in the range of 0.5 ppm to 500 ppm.

  The charge transport layer is formed using a charge transport layer forming coating solution in which the above components are added to a solvent. As a method of dispersing particles (for example, inorganic particles or fluororesin particles) in the charge transport layer forming coating solution, a media dispersing machine such as a ball mill, a vibrating ball mill, an attritor, a sand mill, a horizontal sand mill, stirring, or ultrasonic dispersion Medialess dispersers such as a machine, a roll mill, and a high-pressure homogenizer are used. Examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high-pressure state, and a penetration method in which a fine flow path is dispersed in a high-pressure state.

As a method for applying the charge transport layer forming coating solution on the charge generation layer, dip coating method, push-up coating method, wire bar coating method, spray coating method, blade coating method, knife coating method, curtain coating method, etc. The method is used.
The film thickness of the charge transport layer is desirably set in the range of 5 μm to 50 μm, more desirably 10 μm to 40 μm.

Next, the single layer type photosensitive layer will be described.
The single-layer type photosensitive layer includes, for example, a charge generating material, a binder resin containing the structural unit (A), and fluororesin particles, and includes a charge transporting material as necessary.

The content of the charge generating material in the single-layer type photosensitive layer is about 10% by mass to 85% by mass, desirably 20% by mass to 50% by mass. In addition, the content of the charge transport material is desirably 5% by mass or more and 50% by mass or less.
The film thickness of the single-layer type photosensitive layer is desirably about 5 μm to 50 μm, and more desirably 10 μm to 40 μm.

  Each layer constituting the photosensitive layer may contain additives such as an antioxidant, a light stabilizer, and a heat stabilizer. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

Further, each layer constituting the photosensitive layer may contain at least one electron accepting substance. Examples of the electron acceptor include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, Examples include chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid. Of these, benzene derivatives having an electron-withdrawing substituent such as fluorenone, quinone, Cl, CN, and NO ₂ are particularly desirable.

  The electrophotographic photoreceptor 10 may have a form in which a protective layer is separately provided on the photosensitive layer. In this embodiment, the protective layer corresponds to the outermost surface layer, and the fluororesin particles and the structural unit (A ) Containing a binder resin.

(Charging device)
Examples of the charging device 20 include a contact charger using a conductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube, and the like. Further, examples of the charging device 20 include a non-contact type roller charger and a known charger such as a scorotron charger using a corona discharge or a corotron charger. As the charging device 20, a contact charger is preferable.
In this embodiment, even if a charger that applies a voltage in which an alternating current is superimposed on a direct current is used or a discharge product is likely to be generated, an electrophotography can be obtained even if such a method is adopted. Adhesion / deposition of discharge products on the photoreceptor 10 is suppressed, and white spots in the image are suppressed.

(Exposure equipment)
Examples of the exposure apparatus 30 include optical system devices that expose the surface of the electrophotographic photoreceptor 10 with light such as semiconductor laser light, LED light, and liquid crystal shutter light imagewise. The wavelength of the light source is preferably within the spectral sensitivity region of the electrophotographic photoreceptor 10. As the wavelength of the semiconductor laser, for example, near infrared having an oscillation wavelength around 780 nm is preferable. However, the present invention is not limited to this wavelength, and a laser having an oscillation wavelength of 600 nm or a laser having an oscillation wavelength of 400 nm to 450 nm as a blue laser may be used. Further, as the exposure apparatus 30, for example, a surface emitting laser light source of a multi-beam output type is also effective for color image formation.

(Developer)
The developing device 40 is disposed, for example, opposite to the electrophotographic photoreceptor 10 in the developing region, and includes, for example, a developing container 41 (developing device main body) that contains a two-component developer composed of toner and a carrier, and a replenishment device. A developer storage container (toner cartridge) 47. The developing container 41 includes a developing container main body 41A and a developing container cover 41B that closes the upper end thereof.

  The developing container main body 41A has, for example, a developing roll chamber 42A that accommodates the developing roll 42 therein, and is adjacent to the first stirring chamber 43A and the first stirring chamber 43A adjacent to the developing roll chamber 42A. Second agitating chamber 44A. Further, in the developing roll chamber 42A, for example, a layer thickness regulating member 45 for regulating the layer thickness of the developer on the surface of the developing roll 42 is provided when the developing container cover 41B is attached to the developing container main body 41A. Yes.

  The first stirring chamber 43A and the second stirring chamber 44A are partitioned by, for example, a partition wall 41C. Although not shown, the first stirring chamber 43A and the second stirring chamber 44A are arranged in the longitudinal direction of the partition wall 41C (developing device). (Longitudinal direction) Openings are provided at both ends, and the circulation stirring chamber (43A + 44A) is constituted by the first stirring chamber 43A and the second stirring chamber 44A.

  The developing roll 42 is disposed in the developing roll chamber 42 </ b> A so as to face the electrophotographic photoreceptor 10. Although not shown, the developing roll 42 is provided with a sleeve outside a magnetic roll (fixed magnet) having magnetism. The developer in the first stirring chamber 43A is adsorbed on the surface of the developing roll 42 by the magnetic force of the magnetic roll and is transported to the developing area. Further, the developing roller 42 has a roll shaft supported rotatably on the developing container main body 41A. Here, the developing roll 42 and the electrophotographic photoreceptor 10 rotate in the same direction, and the developer adsorbed on the surface of the developing roll 42 at the opposite portion is opposite to the traveling direction of the electrophotographic photoreceptor 10. It is conveyed from the direction to the development area.

  Further, a bias power source (not shown) is connected to the sleeve of the developing roll 42 so that a developing bias is applied (in this embodiment, a direct current component is applied so that an alternating electric field is applied to the developing region. (A bias in which an alternating current component (DC) is superimposed on (AC) is applied).

  In the first stirring chamber 43A and the second stirring chamber 44A, a first stirring member 43 (stirring / conveying member) and a second stirring member 44 (stirring / conveying member) that convey the developer while stirring are disposed. The first stirring member 43 includes a first rotating shaft that extends in the axial direction of the developing roll 42, and an agitating / conveying blade (protrusion) that is helically fixed to the outer periphery of the rotating shaft. Similarly, the second agitating member 44 includes a second rotating shaft and an agitating / conveying blade (protrusion). The stirring member is rotatably supported by the developing container main body 41A. The first stirring member 43 and the second stirring member 44 are arranged such that the developer in the first stirring chamber 43A and the second stirring chamber 44A is conveyed in the opposite directions by rotation thereof. .

  One end of a replenishment conveyance path 46 for supplying replenishment developer including replenishment toner and replenishment carrier to the second agitation chamber 44A is connected to one end side in the longitudinal direction of the second agitation chamber 44A. The other end of the replenishment conveyance path 46 is connected to a replenishment developer storage container 47 that contains a replenishment developer.

  In this manner, the developing device 40 supplies the replenishment developer from the replenishment developer storage container (toner cartridge) 47 to the development device 40 (second stirring chamber 44A) through the replenishment conveyance path 46.

Here, the developer used in the developing device 40 will be described.
As the developer, a two-component developer including a toner and a carrier is employed.

First, the toner will be described.
The toner includes, for example, toner particles containing a binder resin, a colorant, and, if necessary, other additives such as a release agent, and external additives as necessary.

The toner particles have an average shape factor (shape factor = (ML ² / A) × (π / 4) × 100), and ML represents the maximum length of the particles, where A represents the maximum length of the particles (Representing the projected area) is preferably from 100 to 150, more preferably from 105 to 145, and even more preferably from 110 to 140. Further, the toner preferably has a volume average particle diameter of 3 μm or more and 12 μm or less, more preferably 3.5 μm or more and 10 μm or less, and further preferably 4 μm or more and 9 μm or less.

  The toner particles are not particularly limited by the production method, and for example, a kneading and pulverizing method in which a binder resin, a colorant and a release agent, and a charge control agent and the like are added, if necessary, are kneaded, pulverized, and classified; A method of changing the shape of the particles obtained by the kneading and pulverization method by mechanical impact force or thermal energy; the polymerization monomer of the binder resin is emulsion-polymerized, the formed dispersion, the colorant and the release agent Emulsion polymerization aggregation method to obtain a toner particle by mixing a mold agent and, if necessary, a dispersion of a charge control agent, and agglomerating and heat-fusing; a polymerizable monomer for obtaining a binder resin, and coloring Suspension polymerization method in which a solution of an agent, a release agent and, if necessary, a charge control agent is suspended in an aqueous solvent for polymerization; a binder resin, a colorant and a release agent, and if necessary, a charge control agent Toner particles produced by a solution suspension method in which a solution such as a liquid is suspended in an aqueous solvent and granulated There will be used.

  Further, a known method such as a production method in which the toner particles obtained by the above method are used as a core, and agglomerated particles are further adhered and heated and fused to give a core-shell structure is used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly desirable.

  The toner is produced by mixing the toner particles and the external additive with a Henschel mixer or a V blender. Further, when the toner particles are produced by a wet method, they may be externally added by a wet method.

  On the other hand, as the carrier, iron powder, glass beads, ferrite powder, nickel powder, or the like coated with a resin is used. Further, the mixing ratio of the carrier and the toner is not particularly limited and is set within a known range.

(Transfer device)
Examples of the primary transfer device 51 and the secondary transfer device 52 include a contact transfer charger using a belt, a roller, a film, a rubber blade, and the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, and the like. A transfer charger known per se can be used.

  As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) such as polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber containing a conductive agent is used. Further, as the form of the intermediate transfer member, a cylindrical one is used in addition to the belt shape.

(Cleaning device)
The cleaning device 70 includes a housing 71, a cleaning blade 72 disposed so as to protrude from the housing 71, and a lubricant supply device 60 disposed downstream of the cleaning blade 72 in the rotation direction of the electrophotographic photosensitive member 10. , Including.
The cleaning blade 72 may be supported by the end portion of the casing 71 or may be separately supported by a support member (holder). The form supported at the end of 71 is shown.

First, the cleaning blade 72 will be described.
The cleaning blade 72 is a plate-like member extending in a direction along the rotation axis of the electrophotographic photosensitive member 10, and the tip portion applies pressure upstream of the rotation direction (arrow a) of the electrophotographic photosensitive member 10. It is provided so that it contacts while hanging.
Specifically, as shown in FIG. 5, the cleaning blade 72 includes a first layer 72 </ b> A that contacts the electrophotographic photoreceptor 10 (hereinafter referred to as a contact layer 72 </ b> A) and a second layer that does not contact the electrophotographic photoreceptor 10. The layer 72B (hereinafter referred to as the base layer 72B) and a stacked body may be used. The cleaning blade 72 is joined by bringing the base layer 72B into contact with a support member (for example, an end of the casing 71).
The support member is not limited to the end portion of the casing 71, and may be a member formed of aluminum, stainless steel, or the like.

The cleaning blade 72 is configured such that the contact layer 72A has a type A durometer hardness higher than that of the base layer 72B.
The type A durometer hardness of the contact layer 72A is A77 or more and A85 or less. The rebound resilience at 23 ° C. of the base layer 72B is not less than 35% and not more than 45%.

The contact layer 72A preferably has a Type A durometer hardness of A80 or more and 85 or less.
The overall rebound resilience of the cleaning blade 72 (laminated body of the contact layer 72A and the base layer 72B) is preferably 35% or more and 45% or less.
Here, the type A durometer hardness is a value measured using a type A durometer as defined in JIS K7215 in accordance with the hardness test method indicated in JIS K7311.
The measurement of the impact resilience is in accordance with the Lücke impact resilience test of the impact resilience test method for JIS K6255 vulcanized rubber and thermoplastic rubber. When measuring the impact resilience, the sample to be measured is preliminarily under the temperature (when the impact resilience at 23 ° C. is measured, in a 23 ° C. environment) so that the sample is at the measurement measurement temperature. It is better to leave the sample unattended.

  The cleaning blade 72 is not limited to a two-layer laminated structure, and may be formed of a laminated body of three or more layers, for example, an intermediate layer is provided between the contact layer 72A and the base layer 72B.

Examples of the material constituting the cleaning blade 72 (the contact layer 72A and the base layer 72B) include urethane rubber, silicon rubber, fluorine rubber, propylene rubber, and butadiene rubber. Among these, urethane rubber is preferable.
The urethane rubber (polyurethane) is not particularly limited as long as it is usually used for forming polyurethane, for example, a urethane prepolymer comprising a polyol such as a polyester polyol such as polyethylene adipate or polycaprolactone and an isocyanate such as diphenylmethane diisocyanate. For example, it is preferable to use a crosslinking agent such as 1,4-butanediol, trimethylolpropane, ethylene glycol or a mixture thereof as a raw material.

  When the cleaning blade 72 is manufactured from the urethane rubber (polyurethane), a polyurethane molding method that is usually used may be used, and examples thereof include the following methods. First, the crosslinking agent and the like are added to a prepolymer obtained by mixing the polyol subjected to the dehydration treatment and the isocyanate and reacting at a temperature of 100 ° C. or higher and 120 ° C. or lower for 30 minutes or longer and 90 minutes or shorter. The mixture is poured into a pre-heated mold of a centrifugal molding machine and cured for 30 minutes to 60 minutes. After the curing reaction, a cylindrical sheet having a thickness of 2 mm or more and 3 mm or less is obtained by taking out from the mold. This is cut into strips to obtain the cleaning blade 72.

The cleaning blade 72 made of the laminate can be obtained, for example, by injecting another kind of prepolymer with a time difference when injecting the prepolymer into the mold of the centrifugal molding machine.
Further, the characteristics (hardness, impact resilience, etc.) of each cleaning blade are adjusted by the type of constituent material.

  Here, in the cleaning blade 72, the contact layer 72A in contact with the electrophotographic photosensitive member 10 is particularly preferably composed of the following elastic member.

The elastic member constituting the contact layer 72A has a 100% modulus of preferably 6.5 MPa or more, more preferably 7.0 MPa or more, and further preferably 9.0 MPa or more. On the other hand, the elastic member preferably has a 100% modulus of, for example, 19.6 MPa or less, and more preferably 15.0 MPa or less.
If this 100% modulus is too small, the hardness decreases and the dynamic deflection of the cleaning blade tends to increase, and it may be difficult to suppress uneven wear of the electrostatic latent image holding member. On the other hand, when the 100% modulus of the elastic member is too large, the followability of the cleaning blade to the electrostatic latent image holding member is deteriorated, and it may be difficult to obtain good cleaning properties.

The elastic member constituting the contact layer 72A preferably has an elongation at break of 250% or more, more preferably 300% or more, and further preferably 350% or more. On the other hand, the breaking elongation of the elastic member is preferably 500% or less, more preferably 450% or less, and still more preferably 400% or less.
If the elongation at break is too small, when the foreign substance on the surface of the electrostatic latent image holding member collides with the tip of the cleaning blade with a strong force, it becomes difficult for the tip of the cleaning blade to follow and deform within a relatively short time. Edge chipping may occur. On the other hand, if the elongation at break is too large, the followability (adhesiveness) to the electrophotographic photosensitive member is likely to increase, the frictional force with the electrophotographic photosensitive member increases, and as a result, wear of the cleaning blade tends to increase. is there.

  Here, both 100% modulus and elongation at break are values measured according to J1SK6251. That is, a dumbbell-shaped No. 3 test piece is used and measured at a tensile speed of 500 mm / min to obtain a stress-strain curve (ambient temperature 23 ° C.), which is obtained based on this curve. In addition, the measuring apparatus used the Toyo Seiki Co., Ltd. product and the strograph AE elastomer.

Specifically, for example, an elastomer material including a hard segment and a soft segment may be selected as the elastic member constituting the contact layer 72A. By including both the hard segment and the soft segment, the elastomer material tends to satisfy the conditions of the contact layer 72A (type A durometer hardness, 100% modulus, elongation at break).
“Hard segment” and “soft segment” are the materials that make up the former in the elastomer material and are relatively harder than the materials that make up the latter. Means a segment made of a material relatively softer than the material constituting the former.

The mass ratio of the material composing the hard segment to the total amount of the hard segment and the material composing the soft segment (hereinafter sometimes referred to as “hard segment material ratio”) is in the range of 46 mass% to 96 mass%. It is preferable that it is in the range of 50% by mass or more and 90% by mass or less, and more preferably in the range of 60% by mass or more and 85% by mass or less.
If the hard segment material ratio is too small, the wear resistance of the elastic member tends to be lowered, and wear may occur at an early stage, making it difficult to maintain good cleaning properties over a long period of time. On the other hand, if the hard segment material ratio is too large, the edge tip becomes too hard and the flexibility and extensibility tend to decrease, and chipping occurs early, making it difficult to maintain good cleaning properties over a long period of time. is there.

The combination of the material constituting the hard segment (hereinafter referred to as the hard segment material) and the material constituting the soft segment (hereinafter referred to as the soft segment material) can be selected from known resin materials. Such a combination is suitable.
That is, it is preferable to use a polyurethane resin as the hard segment material. In this case, the weight average molecular weight of the polyurethane resin is preferably in the range of 1000 or more and 4000 or less, and more preferably in the range of 1500 or more and 3500 or less. If the weight average molecular weight is too small, the elasticity of the polyurethane resin tends to be lost when the cleaning blade is used in a low temperature environment, and cleaning failure may easily occur. Also, if the weight average molecular weight is too large, the permanent deformation of the polyurethane resin tends to increase, and it becomes difficult to maintain the pressing force with which the cleaning blade comes into contact with the electrophotographic photosensitive member, resulting in poor cleaning. is there.
Examples of the polyurethane resin used as the hard segment material as described above include Daicel Chemical Industries, Plaxel 205, Plaxel 240, and the like.

  When a polyurethane resin is used as the hard segment material, it is preferable to use (a) a resin having a functional group capable of reacting with an isocyanate group as the soft segment material combined with the hard segment material. The physical properties of this resin are as follows: (b) glass transition temperature of 0 ° C. or lower, (c) viscosity at 25 ° C. in the range of 600 mPa · s to 35000 mPa · s, (d) weight average molecular weight of 700 to 3000 It is preferable to be within the range. If these physical properties are not satisfied, the moldability at the time of producing the cleaning blade 72 (contact layer 72A) may be easily deteriorated, or the characteristics of the cleaning blade itself may be deteriorated.

  These physical properties are more preferably in the range of glass transition temperature of −10 ° C. or lower, viscosity at 25 ° C. of 1000 mPa · s to 3000 mPa · s, and weight average molecular weight of 900 to 2800. In addition, when the cleaning blade 72 (contact layer 72A) is manufactured using centrifugal molding, the viscosity at 25 ° C. is preferably in the range of 600 mPa · s to 3500 mPa · s.

  The soft segment material satisfying the structures and physical properties shown in the above (a) to (d) can be selected from known resins, but at least a terminal having a flexible functional group capable of reacting with an isocyanate group. A certain resin is preferable. In addition, this resin is preferably an aliphatic resin having a linear structure from the viewpoint of flexibility.

  Specific examples of the soft segment material include an acrylic resin containing two or more hydroxyl groups, a polybutadiene resin containing two or more hydroxyl groups, and an epoxy resin having two or more epoxy groups.

  Examples of the acrylic resin containing two or more hydroxyl groups include Actflow (grade: UMB-2005B, UMB-2005P, UMB-2005, UME-2005, etc.) manufactured by Soken Chemical Co., Ltd. As polybutadiene resin containing the above hydroxyl groups, Idemitsu Kosan Co., Ltd. make, R-45HT etc. are mentioned, for example.

Moreover, as an epoxy resin which has two or more epoxy groups, it does not have a hard and brittle property like the conventional general epoxy resin, and the thing which is flexible and tougher than the conventional epoxy resin is good.
As this epoxy resin, for example, in terms of molecular structure, those having a structure (flexible skeleton) that increases the mobility of the main chain in the main chain structure are suitable. Examples include a skeleton, a cycloalkane skeleton, and a polyoxyalkylene skeleton, and a polyoxyalkylene skeleton is particularly preferable.
Moreover, as a physical property surface of the epoxy resin, an epoxy resin having a lower viscosity than the molecular weight of the conventional epoxy resin is preferable. In particular,
The epoxy resin has a weight average molecular weight in the range of 900 ± 100, preferably a viscosity at 25 ° C. in the range of 15000 ± 5000 mPa · s, and in the range of 15000 ± 3000 mPa · s. More preferably.
As an epoxy resin which has such a characteristic, Dainippon Ink and Chemicals make, EPLICON EXA-4850-150 etc. are mentioned, for example.

Next, the arrangement conditions of the cleaning blade 72 will be described.
The cleaning blade 72 has an angle A in contact with the electrophotographic photosensitive member 10 of 7.0 ° or more and 15.5 ° or less (preferably 9.0 ° or more and 12.0 ° or less), and with respect to the electrophotographic photosensitive member 10. pressing pressure N is 0.6 gf / mm ² or more 6.0gf / mm ² or less (preferably 1.5 gf / mm ² or more 5.0gf / mm ² or less) is set to, it is possible to dispose.
Here, the angle A at which the cleaning blade 72 is in contact with the electrophotographic photosensitive member 10 is specifically the contact layer of the cleaning blade 72 when viewed from the rotational axis direction of the electrophotographic photosensitive member 10 as shown in FIG. 72A is an angle (°) between the surface facing the electrophotographic photosensitive member 10 and the upstream side in the rotation direction of the tangent L at a position where the contact layer 72A of the cleaning blade 72 is in contact with the electrophotographic photosensitive member 10.
The pressing pressure N of the cleaning blade 72 against the electrophotographic photosensitive member 10 is the center of the electrophotographic photosensitive member 10 at a position where the contact layer 72A of the cleaning blade 72 is in contact with the electrophotographic photosensitive member 10, as shown in FIG. It is the pressure (gf / mm < ² >) pressed toward.

The thickness (total thickness) of the cleaning blade 72 is, for example, preferably from 1 mm to 3 mm, preferably from 1.5 mm to 2.5 mm, and more preferably from 1.8 mm to 2.2 mm.
On the other hand, the thickness of the contact layer 72A is desirably 0.05 mm or more and 1.5 mm or less, and more desirably 0.1 mm or more and 1.0 mm or less.
Further, the thickness of the base layer 72B is preferably, for example, 0.9 mm or more and 2.9 mm or less, and more preferably 1.5 mm or more and 2.0 mm or less.

Next, the lubricant supply device 60 will be described.
The lubricant supply device 60 is provided, for example, inside the cleaning device 70 and upstream of the cleaning blade 72 in the rotation direction of the electrophotographic photosensitive member 10.

  The lubricant supply device 60 includes, for example, a rotating brush 61 disposed in contact with the electrophotographic photosensitive member 10 and a solid lubricant 62 disposed in contact with the rotating brush 61. . In the lubricant supply device 60, the rotating brush 61 is rotated while being in contact with the solid lubricant 62, whereby the lubricant 62 adheres to the rotating brush 61, and the attached lubricant 62 becomes the electrophotographic photosensitive member. The film of the lubricant 62 is formed on the surface 10.

The lubricant supply device 60 is not limited to the above form, and may be a form that employs a rubber roller instead of the rotating brush 61, for example.
Examples of the lubricant 62 include metal soap and wax.

  Next, the operation of the image forming apparatus 101 according to the present embodiment will be described. First, the electrophotographic photoreceptor 10 rotates along the direction indicated by the arrow a, and at the same time is negatively charged by the charging device 20.

  The electrophotographic photoreceptor 10 whose surface is negatively charged by the charging device 20 is exposed by the exposure device 30, and a latent image is formed on the surface.

  When the portion where the latent image is formed on the electrophotographic photoreceptor 10 approaches the developing device 40, the developing device 40 (developing roll 42) attaches toner to the latent image and forms a toner image.

  When the electrophotographic photosensitive member 10 on which the toner image is formed further rotates in the direction of arrow a, the toner image is transferred to the outer surface of the intermediate transfer member 50.

  When the toner image is transferred to the intermediate transfer member 50, the recording paper P is supplied to the secondary transfer device 52 by the recording paper supply device 53, and the toner image transferred to the intermediate transfer member 50 is transferred by the secondary transfer device 52. Transferred onto the recording paper P. As a result, a toner image is formed on the recording paper P.

  The toner image is fixed on the recording paper P on which the image is formed by the fixing device 80.

  Here, after the toner image is transferred to the intermediate transfer member 50, the electrophotographic photosensitive member 10 is transferred, and then the lubricant supply device 60 supplies the lubricant 62 to the surface of the electrophotographic photosensitive member 10. A film of the lubricant 62 is formed on the surface of the photographic photoreceptor 10. Thereafter, the toner and discharge products remaining on the surface are removed by the cleaning blade 72 of the cleaning device 70. Then, the electrophotographic photosensitive member 10 from which the transfer residual toner and discharge products are removed in the cleaning device 70 is charged again by the charging device 20 and is exposed in the exposure device 30 to form a latent image.

Further, for example, as illustrated in FIG. 2, the image forming apparatus 101 according to the present embodiment includes an electrophotographic photosensitive member 10, a charging device 20, a developing device 40, a lubricant supply device 60, and a cleaning in a housing 11. A configuration including a process cartridge 101A that integrally accommodates the apparatus 70 may be employed. The process cartridge 101A integrally contains a plurality of members and is attached to and detached from the image forming apparatus 101. In the image forming apparatus 101 shown in FIG. 2, the developing device 40 is not provided with the replenishment developer storage container 47.
The configuration of the process cartridge 101A is not limited to this. For example, the process cartridge 101A only needs to include at least the electrophotographic photoreceptor 10 and the cleaning device 70. For example, the charging device 20, the exposure device 30, the developing device 40, and the primary At least one selected from the transfer device 51 may be provided.

  In addition, the image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration. For example, the cleaning is performed around the electrophotographic photosensitive member 10 and downstream of the primary transfer device 51 in the rotation direction of the electrophotographic photosensitive member 10. A first neutralization device may be provided on the upstream side of the rotation direction of the electrophotographic photosensitive member relative to the device 70 so that the polarity of the remaining toner is aligned and easily removed with a cleaning brush. Even if the second static eliminating device for neutralizing the surface of the electrophotographic photosensitive member 10 is provided on the downstream side in the rotational direction of the electrophotographic photosensitive member relative to the upstream side in the rotational direction of the electrophotographic photosensitive member relative to the charging device 20. Good.

  Further, the image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration, and may employ a known configuration, for example, a method of directly transferring a toner image formed on the electrophotographic photosensitive member 10 to the recording paper P. Alternatively, a tandem image forming apparatus may be employed.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention. Unless otherwise specified, all “parts” mean “parts by mass”.

[Production of photoconductor]
(Preparation of photoreceptor 1)
100 parts by mass of zinc oxide (average particle diameter: 70 nm, manufactured by Teica, specific surface area value: 15 m ² / g) is stirred and mixed with 500 parts by mass of methanol, and KBM603 (manufactured by Shin-Etsu Chemical Co., Ltd.) is used as a silane coupling agent. 25 parts by mass was added and stirred for 2 hours. Thereafter, methanol was distilled off under reduced pressure, and baking was performed at 120 ° C. for 3 hours to obtain silane coupling agent surface-treated zinc oxide particles.
60 parts by mass of the surface-treated zinc oxide particles, 0.6 parts by mass of alizarin, 13.5 parts by mass of blocked isocyanate (Sumidule 3173, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, and butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.) 15 parts by mass, 38 parts by mass of a solution obtained by dissolving 85 parts by mass of methyl ethyl ketone and 25 parts by mass of methyl ethyl ketone are mixed, and 4 hours in a sand mill using glass beads having a diameter of 1 mm. Was dispersed to obtain a dispersion. To the obtained dispersion, 0.005 parts by mass of dioctyltin dilaurate and 4.0 parts by mass of silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone) are added as a catalyst to obtain an undercoat layer coating solution. It was. This coating solution was applied on an aluminum substrate having a diameter of 30 mm by a dip coating method, followed by drying and curing at 180 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 23 μm.

  Next, as a charge generation material, a mixture of 15 parts by mass of hydroxygallium phthalocyanine crystal, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and 300 parts by mass of n-butyl alcohol is used. Then, using a glass bead having a diameter of 1 mm, it was dispersed in a sand mill for 4 hours to obtain a coating solution for a charge generation layer. This charge generation layer coating solution was dip-coated on the undercoat layer and dried to obtain a charge generation layer having a thickness of 0.2 μm.

Next, as a material for forming the charge transport layer, as liquid A: tetrafluoroethylene resin particles (average particle size: 0.2 μm) 1.0 part by mass, fluorine-based graft polymer (GF300, manufactured by Toagosei Co., Ltd., weight average) 0.01 part by mass of molecular weight 30,000) was kept at a liquid temperature of 20 ° C. together with 3 parts by mass of tetrahydrofuran and 1 part by mass of toluene and stirred for 48 hours to obtain a tetrafluoroethylene resin particle suspension. Next, as the B liquid: 4 parts by mass of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine as a charge transport material, and a copolymerization ratio m represented by the following structural formula (A1): 6 parts by mass of n = 20: 80 biphenyl copolymerized polycarbonate resin (weight average molecular weight 72,000) and 0.1 part by mass of 2,6-di-tert-butyl-4-methylphenol as an antioxidant are mixed. Then, 24 parts by mass of tetrahydrofuran and 11 parts by mass of toluene were mixed and dissolved.
After the A liquid was added to the B liquid and stirred and mixed, the pressure was increased to 500 kgf / cm ² using a high-pressure homogenizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) equipped with a through-type chamber having a fine flow path. 10 ppm of silicone oil (trade name: KP-323, manufactured by Shin-Etsu Silicone) was added to the liquid obtained by repeating the dispersion treatment three times, and stirred to obtain a coating liquid for forming a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 115 ° C. for 30 minutes to form a charge transport layer having a thickness of 20 μm.

(Preparation of photoconductor 2)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, the biphenyl copolymerization type represented by the structural formula (A1) and having a copolymerization ratio m: n = 5: 95 (weight average molecular weight 72,000). Photoreceptor 2 was produced in the same manner as Photoreceptor 1 except that polycarbonate resin was used.

(Preparation of photoreceptor 3)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, the biphenyl copolymerization type represented by the structural formula (A1) and having a copolymerization ratio m: n = 0: 100 (weight average molecular weight 39,000). Photoreceptor 3 was produced in the same manner as Photoreceptor 1 except that polycarbonate resin was used.

(Preparation of photoconductor 4)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, a polycarbonate resin represented by the following structural formula (A2) and having a copolymerization ratio m: n = 20: 80 (weight average molecular weight 75,000) is used. A photoreceptor 4 was produced in the same manner as the photoreceptor 1, except that

(Preparation of photoconductor 5)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, the biphenyl copolymerization type represented by the structural formula (A2) and having a copolymerization ratio m: n = 5: 95 (weight average molecular weight 75,000). Photoreceptor 5 was produced in the same manner as Photoreceptor 1 except that polycarbonate resin was used.

(Preparation of photoreceptor 6)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, the biphenyl copolymerization type represented by the structural formula (A2) and having a copolymerization ratio m: n = 0: 100 (weight average molecular weight 60,000). Photoreceptor 6 was produced in the same manner as Photoreceptor 1 except that polycarbonate resin was used.

(Preparation of photoconductor 7)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, the biphenyl copolymerization type represented by the structural formula (A1) and having a copolymerization ratio m: n = 40: 60 (weight average molecular weight 50,000). Photoreceptor 7 was produced in the same manner as Photoreceptor 1 except that polycarbonate resin was used.

(Preparation of photoconductor 8)
Instead of the biphenyl copolymerization type polycarbonate resin described in the photoreceptor 1, a biphenyl copolymerization type represented by the structural formula (A2) and having a copolymerization ratio m: n = 40: 60 (weight average molecular weight 50,000). A photoconductor 8 was produced in the same manner as the photoconductor 1 except that polycarbonate resin was used.

  Table 1 summarizes the structural formula, copolymerization ratio m: n, and fluororesin particle amount of the polycarbonate used in the preparation of the above photoreceptors.

[Production of cleaning blade]
(Preparation of cleaning blade 1)
Polycaprolactone polyol (Daicel Chemical Industries, Plaxel 205, average molecular weight 529, hydroxyl value 212 KOHmg / g) and polycaprolactone polyol (Daicel Chemical Industries, Plaxel 240, average molecular weight 4155, hydroxyl value 27 KOHmg / g) A hard segment material of a polyol component was prepared.
In addition, an acrylic resin containing two or more hydroxyl groups (Act Flow UMB-2005B, manufactured by Soken Chemical Co., Ltd.) was prepared as a soft segment material.
And the said hard segment material and the said soft segment material were mixed in the ratio of 8: 2 (mass ratio).

Next, 6,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT, hereinafter referred to as “MD1”) is used as an isocyanate compound with respect to 100 parts by mass of the mixture of the hard segment material and the soft segment material. .26 parts by mass was added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere. The amount of isocyanate compound used in this reaction was selected so that the ratio of isocyanate group to hydroxyl group contained in the reaction system (isocyanate group / hydroxyl group) was 0.5.
Next, 34.3 parts by mass of the above isocyanate compound was further added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere to obtain a prepolymer. The total amount of isocyanate compound used in the use of the prepolymer was 40.56 parts by mass.
Next, this prepolymer was heated to 100 ° C. and degassed for 1 hour under reduced pressure. Thereafter, 7.14 parts by mass of a mixture of 1,4-butanediol and trimethylolpropane (mass ratio = 60/40) is added to 100 parts by mass of the prepolymer, and it is sufficiently not to foam for 3 minutes. Mixed. This mixture was cured at 140 ° C. for 10 minutes with a centrifugal molding machine with an adjusted mold to obtain a contact layer material.
Next, the contact layer material was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C., and a curing reaction was performed for 10 minutes to form a flat contact layer.

On the other hand, instead of the mixture of the hard segment material and the soft segment material, Coronate 4086 (manufactured by Nippon Polyurethane Industry Co., Ltd.) as the polyol component, and NIPPOLAN 4038 (Nippon polyurethane) as the isocyanate compound with respect to 100 parts by mass of the polyol component A base layer material treated in the same manner as the contact layer material was obtained except that 6.8 parts by mass of Kogyo Co., Ltd. was added.
Next, the base layer material was poured into a centrifugal molding machine in which the contact layer was formed into a flat plate shape and allowed to cure for 1 hour to form a flat base layer on the contact layer to obtain a flat plate having a two-layer structure. . This flat plate was heated at 110 ° C. for 24 hours to allow the crosslinking reaction to proceed, and then cooled and cut to a predetermined size to obtain a cleaning blade having a thickness of 2 mm and a width of 333 mm.
The cleaning blade thus obtained was designated as cleaning blade 1.

(Preparation of cleaning blade 2)
As a material for the contact layer, instead of a mixture of a hard segment material and a soft segment material, 100 parts by mass of a prepolymer obtained by using polyethylene adipate (manufactured by Sanyo Chemical Industries, San Ester 2620), and (1 , 4-butanediol: trimethylolpropane: ethylene glycol = 80: 10: 10) except that 7.6 parts by mass was added to obtain a cleaning blade 2 in the same manner as the cleaning blade 1.

(Preparation of cleaning blade 3)
Only the material for the base layer in the cleaning blade 1 was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C. and cured for 1 hour to obtain a flat plate having a single layer structure. This flat plate was heated at 110 ° C. for 24 hours to allow the crosslinking reaction to proceed, then cooled and cut to the desired dimensions to obtain a blade having a thickness of 1 mm and a width of 333 mm. Then, two blades were produced and bonded to obtain a cleaning blade 3.

(Preparation of cleaning blade 4)
A flat plate having a single layer structure obtained in the cleaning blade 3 was cut into a desired size to obtain a blade having a thickness of 2 mm and a width of 333 mm. This was designated as a cleaning blade 4.

(Preparation of cleaning blade 5)
An acrylic resin containing two or more hydroxyl groups (Akaflow Chemicals, Actflow UMB-2005B) was prepared as a soft segment material.
Then, the hard segment material obtained in the cleaning blade 1 and the soft segment material were mixed at a ratio of 8: 2 (mass ratio).

Next, 6,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT, hereinafter referred to as “MD1”) is used as an isocyanate compound with respect to 100 parts by mass of the mixture of the hard segment material and the soft segment material. .26 parts by mass was added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere. The amount of isocyanate compound used in this reaction was selected so that the ratio of isocyanate group to hydroxyl group contained in the reaction system (isocyanate group / hydroxyl group) was 0.5.
Next, 34.3 parts by mass of the above isocyanate compound was further added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere to obtain a prepolymer. The total amount of isocyanate compound used in the use of the prepolymer was 40.56 parts by mass.

  Next, this prepolymer was heated to 100 ° C. and degassed for 1 hour under reduced pressure. Thereafter, 7.14 parts by mass of a mixture of 1,4-butanediol and trimethylolpropane (mass ratio = 60/40) is added to 100 parts by mass of the prepolymer, and it is sufficiently not to foam for 3 minutes. Mixed.

  Next, the mixture was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C., and a curing reaction was performed for 10 minutes to obtain a flat plate having a single layer structure. After cooling the flat plate, a cleaning blade 5 having a thickness of 2 mm and a width of 333 mm was obtained.

(Preparation of cleaning blade 6)
Polycaprolactone polyol (Daicel Chemical Industries, Plaxel 205, average molecular weight 529, hydroxyl value 212 KOHmg / g) and polycaprolactone polyol (Daicel Chemical Industries, Plaxel 240, average molecular weight 4155, hydroxyl value 27 KOHmg / g) A hard segment material of a polyol component was prepared.
In addition, an acrylic resin containing two or more hydroxyl groups (Act Flow UMB-2005B, manufactured by Soken Chemical Co., Ltd.) was prepared as a soft segment material.
And the said hard segment material and the said soft segment material were mixed in the ratio of 8: 2 (mass ratio).

  Next, 6,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT, hereinafter referred to as “MD1”) is used as an isocyanate compound with respect to 100 parts by mass of the mixture of the hard segment material and the soft segment material. .26 parts by mass was added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere. The amount of the isocyanate compound used in this reaction is selected so that the ratio of isocyanate group to hydroxyl group (isocyanate group / hydroxyl group) contained in the reaction system is 0.5.

Next, 34.3 parts by mass of the above isocyanate compound was further added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere to obtain a prepolymer. The total amount of isocyanate compound used in the use of the prepolymer was 40.56 parts by mass.
Next, this prepolymer was heated to 100 ° C. and degassed for 1 hour under reduced pressure. Thereafter, 7.14 parts by mass of a mixture of 1,4-butanediol and trimethylolpropane (mass ratio = 60/40) is added to 100 parts by mass of the prepolymer, and it is sufficiently not to foam for 3 minutes. Mixed. This mixture was cured at 140 ° C. for 10 minutes with a centrifugal molding machine with an adjusted mold to obtain a contact layer material.

Next, the contact layer material was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C., and a curing reaction was performed for 10 minutes to form a flat contact layer.
On the other hand, instead of the mixture of the hard segment material and the soft segment material, Coronate 4086 (manufactured by Nippon Polyurethane Industry Co., Ltd.) as the polyol component, and NIPPOLAN 4038 (Nippon polyurethane) as the isocyanate compound with respect to 100 parts by mass of the polyol component A base layer material treated in the same manner as the contact layer material was obtained except that 8.6 parts by mass of Kogyo Co., Ltd. was added.
Next, the base layer material was poured into a centrifugal molding machine in which the contact layer was formed into a flat plate shape and allowed to cure for 1 hour to form a flat base layer on the contact layer to obtain a flat plate having a two-layer structure. . This flat plate was heated at 110 ° C. for 24 hours to allow the crosslinking reaction to proceed, and then cooled and cut to a predetermined size to obtain a cleaning blade having a thickness of 2 mm and a width of 333 mm.
The cleaning blade thus obtained was designated as cleaning blade 6.

(Cleaning blade 7-9)
In addition to the above, the contact layer type A dilometer hardness A77, the base layer rebound resilience 35%, the type A dilometer hardness A60 cleaning blade 7, and the contact layer type A dilometer hardness A85, the base layer rebound A cleaning blade 8 having an elastic modulus of 45%, a type A dynamometer hardness A65, a contact layer type A dynamometer hardness A87, a base layer rebound resilience of 48%, and a type A dynamometer hardness A67 cleaning blade 9 was prepared.

  Here, Table 2 shows the characteristics of the obtained cleaning blades.

[Examples 1 to 10, Comparative Examples 1 to 11]
According to the combination of the photoreceptor and the cleaning blade shown in Table 3, these were mounted on a modified machine of Apeos Port IIC4300 (manufactured by Fuji Xerox Co., Ltd.), and the following evaluation was performed. The results are shown in Table 3.

(Evaluation)
-Photoconductor wear-
Photoreceptor wear was evaluated using A4 paper (C2 paper manufactured by Fuji Xerox Co., Ltd.) before and after forming 50,000 images at an image density of 5% under low temperature and low humidity (10 ° C., 15 RH%). The film thickness of the entire layer was measured, and the difference between the average values was evaluated as Δ film thickness.
A: Δ film thickness <5 μm
○: 5 μm ≦ Δ film thickness <10 μm
Δ: 10 μm ≦ Δ film thickness <15 μm
×: 15 μm ≦ Δ film thickness

-Uneven photoconductor wear-
Evaluation of uneven wear of the photoconductor was performed by measuring the film thickness of the photosensitive layer center and the upper end portion of the photosensitive layer 150 mm coated from the center of the photosensitive layer in the above wear evaluation, and the difference was evaluated as Δ uneven wear.
A: Δ Uneven wear <1.5 μm
○: 1.5 μm ≦ Δ uneven wear <3 μm
Δ: 3 μm ≦ Δ Uneven wear <5 μm
×: 5 μm ≦ Δ uneven wear

-Blade missing-
Blade evaluation was performed after forming 20,000 images at an image density of 5% under high temperature and high humidity (30 ° C., 80 RH%) using A4 paper (Fuji Xerox C2 paper). The photoreceptor contact surface of the cleaning blade was observed with a laser microscope and evaluated for the presence or absence of chipping.
○: No chipping occurred ×: Chipping occurred

-Blade dripping-
The evaluation of the blade curl was performed by forming 20,000 images at an image density of 1% under low temperature and low humidity (10 ° C., 15 RH%) using A4 paper (C2 paper manufactured by Fuji Xerox Co., Ltd.). The presence or absence of blade wrinkling was observed and evaluated.
○: No drooling occurred ×: Drowning occurred

-Photoconductor scratches-
Photoreceptor scratches were evaluated by evaluating the ten-point average roughness Rz on the surface of a photoconductor after forming 20,000 images at an image density of 5% using A4 paper (Fuji Xerox C2 paper). Carried out. The ten-point average roughness Rz was measured using a surface roughness shape measuring instrument (SURFCOM 1500D-3DF, manufactured by Tokyo Seimitsu Co., Ltd.). Measurement conditions are: detector: S1500 standard / measurement force: 0.7 mN, probe: DT43801 / tip shape: 2 μm R60 ° conical diamond, measurement area: 4.0 × 2.0 mm, measurement pitch: X0.02 mm / Y0 0.02 mm, measurement speed: 0.6 mm / s. In addition, as a measurement point, the measurement was performed for each of the vicinity of the center of the photoconductor (position of 170 mm from the end) and the vicinity of the end (position of 10 mm from the end). Calculated as Rz.
○: Rz is 1.0 μm or less Δ: Rz is more than 1.0 μm and less than 3.0 μm (a level where there is no problem in image quality)
×: Rz is 3.0 μm or more (white streaks appear on the image)

  From the above results, it can be seen that in this example, as compared with the comparative example, any evaluation of photoconductor wear, photoconductor uneven wear, blade chipping, blade curl, and photoconductor scratch was obtained, and good results were obtained.

DESCRIPTION OF SYMBOLS 1 Undercoat layer, 2 Charge generation layer, 3 Charge transport layer, 4 Conductive substrate, 6 Single layer type photosensitive layer, 10 Electrophotographic photoreceptor, 10A Electrophotographic photoreceptor, 10B Electrophotographic photoreceptor, 20 Charging device, 30 Exposure device, 40 developing device, 41 developing container, 41A developing container body, 41B developing container cover, 41C wall, 42 developing roll, 42A developing roll chamber, 43 stirring member, 43A stirring chamber, 44 stirring member, 44A stirring chamber, 45 Layer thickness regulating member, 46 Supply transport path, 47 Supply developer container, 50 Intermediate transfer member, 50A Support roller, 50B Support roller, 50C Back roller, 50D Drive roller, 51 Primary transfer device, 52 Secondary transfer device, 53 Recording paper supply device, 53A Conveying roller, 53B Induction slope, 54 Intermediate transfer member cleaning device, 60 , 70 cleaning unit, 71 housing, 72 cleaning blade, 80 a fixing device, 81 a fixing roller, 82 conveyor, 101 an image forming apparatus, 101A process cartridge

Claims (6)

An electrophotographic photosensitive member having at least a photosensitive layer on a conductive substrate, the outermost surface layer containing fluororesin particles and a binder resin containing the following structural unit (A);
Charging means for charging the electrophotographic photoreceptor;
Electrostatic latent image forming means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image; and
Toner image forming means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring a toner image formed on the electrophotographic photosensitive member to a transfer target;
A cleaning blade configured by cleaning a surface of the electrophotographic photosensitive member and including a laminate of a first layer in contact with the electrophotographic photosensitive member and a second layer not in contact with the electrophotographic photosensitive member, A cleaning means having a cleaning blade in which the hardness of one type A durometer is higher than that of the second layer and is A77 or more and A85 or less, and the rebound resilience at 23 ° C. of the second layer is 35% or more and 45% or less. When,
An image forming apparatus.

The binder resin containing the structural unit (A) is a binder resin represented by the following structural formulas (A1) to (A2) (however, in the following structural formula (A2), m: n represents a copolymerization ratio; 2. The image forming apparatus according to claim 1, wherein m: n = 95: 5 to 5:95.

  The image forming apparatus according to claim 2, wherein the binder resin represented by the structural formulas (A1) to (A2) has a copolymerization ratio m: n = 10: 90 to 40:60. An electrophotographic photosensitive member having at least a photosensitive layer on a conductive substrate, the outermost surface layer containing fluororesin particles and a binder resin containing the following structural unit (A);
A cleaning blade configured by cleaning a surface of the electrophotographic photosensitive member and including a laminate of a first layer in contact with the electrophotographic photosensitive member and a second layer not in contact with the electrophotographic photosensitive member, A cleaning means having a cleaning blade in which the hardness of one type A durometer is higher than that of the second layer and is A77 or more and A85 or less, and the rebound resilience at 23 ° C. of the second layer is 35% or more and 45% or less. When,
With
A process cartridge that is detachable from the image forming apparatus.

The invention according to claim 5
The binder resin containing the structural unit (A) is a binder resin represented by the following structural formulas (A1) to (A2) (however, in the following structural formula (A2), m: n represents a copolymerization ratio; 5. The process cartridge according to claim 4, wherein m: n = 95: 5 to 5:95.

  6. The process cartridge according to claim 5, wherein the binder resin represented by the structural formulas (A1) to (A2) exhibits a copolymerization ratio m: n = 10: 90 to 40:60.

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