JP2017181692A - Electrophotographic process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process cartridge that prevents an influence of contamination of a charging target body, especially a photoreceptor and can stably form a high-quality electrophotographic image, and an image forming apparatus with high durability using the same.SOLUTION: There is provided an electrophotographic process cartridge comprising at least an electrophotographic photoreceptor and charging means that charges the electrophotographic photoreceptor, where the charging means is a charging roller that contains a compound represented by the following formula (1), and the electrophotographic photoreceptor includes a surface layer having a glass transition point of 85°C or more. In the formula (1), n represents an integer of 1 to 3.SELECTED DRAWING: None

Description

  The present invention relates to an electrophotographic photosensitive member, an image forming apparatus, and an electrophotographic cartridge used for a copying machine, a printer, and the like.

As a means for charging an electrophotographic photosensitive member of an image forming apparatus such as an electrophotographic apparatus (copying machine, optical printer, etc.), an electrostatic recording apparatus, a charged member such as a dielectric, a charged member to which a voltage is applied is charged. Contact charging is known in which the surface of an object to be charged is charged in proximity to or in contact with a body.
Compared with corona charging, contact charging has advantages such as lowering the voltage applied to the charging member and reducing the amount of ozone generated. Such a charging member for contact charging has low surface conductivity in order to prevent leakage due to uniformity of the charged body and pinholes / scratches on the surface of the charged body such as a photoreceptor. Is required. In addition, such a charging member is required to have a low hardness in order to obtain a uniform nip by pressing the member to be charged with a predetermined pressure. In response to such demands, metal oxides such as carbon black, graphite, titanium oxide and silver oxide, metal powders such as Cu and Ag, and the like are applied to the particle surface on a conductive core such as metal. Conductive elastic body containing a polar polymer such as a rubber roller having a conductive elastic body layer in which conductive particles such as particles made conductive by coating are mixed and dispersed in rubber, an acrylonitrile-butadiene rubber), and an epichlorohydrin copolymer. A charging member such as a rubber roller having a layer has been proposed.

  However, the rubber composition constituting the conductive elastic layer includes a residue of a reaction initiator and a by-product generated at the time of synthesizing the base polymer, a low molecular component of the base polymer, a rubber member Components such as a vulcanizing agent, a softening agent, a plasticizer, an anti-aging agent, and a conductive agent for controlling conductivity added during molding are included. Therefore, if such a charging member is pressed against the member to be charged and left for a long time in a high temperature and high humidity state, the charging member and the member to be charged are fused or the charging member has a low resistance in the conductive elastic layer. In some cases, molecular components ooze out, and the surface of the charged body is contaminated and damaged, thereby degrading the quality of the electrophotographic image.

On the other hand, the charging member is contaminated by the adhesion of the developer or the like to the surface by repeated use, and this dirt accumulates, which may cause image defects such as defective charging or vertical streaks due to abnormal charging.
In response to such problems, a charging member having a so-called multilayer structure in which a low molecular component exudation from the rubber layer or a layer made of a non-adhesive resin is provided on the surface of the conductive elastic layer has been proposed. Yes. However, it is disadvantageous in cost to add layers according to each technical problem, and in a charging member having a multi-layer structure, the charging function of the object to be charged, which is the original function of the charging member, is maintained. It was not easy to do.

  In order to prevent contamination of organophotoreceptors due to leakage of low-molecular components from the conductive elastic layer, an example of a solution without adopting a multilayer structure is the combination of epichlorohydrin containing ionic conductive agent and ethylene oxide. A charging roller having an elastic layer made of rubber mainly composed of a polymer is immersed in a treatment solution containing an isocyanate-containing compound and heated to cure the surface of the elastic layer, thereby suppressing contamination of the photoreceptor. A technique is disclosed (Patent Document 1).

On the other hand, in order to solve the above-mentioned problem, the surface of the conductive elastic layer contains a rubber component crosslinked to the conductive elastic layer, and the skin portion of the conductive elastic layer has an intramolecular structure together with the rubber component. It has been reported that it contains a siloxane cross-linked product having polyester and / or polystyrene as a component and having a cross-linking point represented by a Si-O bond, resulting in a charging member with good charging characteristics and excellent stain resistance. (Patent Document 2).

Japanese Patent Application Laid-Open No. 10-45953 JP 2006-350097 A

  However, the cross-linking material described in Patent Document 2 has a problem in that the hardness of the conductive roller as a whole is increased and it is difficult to control the nip and the like. Although the effect was obtained, it was disadvantageous in terms of cost. Furthermore, according to the study by the present inventors, the charging roller using a technique for curing the surface of the elastic layer by immersing it in a treatment liquid containing an isocyanate-containing compound and heating it is surely applied to an organic photoreceptor. Although it was effective in preventing pollution, it was still not enough. Further, the invention described in Patent Document 1 does not take into consideration any surface contamination of the charging roller itself.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic apparatus capable of stably forming a high-quality electrophotographic image and a process cartridge used therefor, even if a charged body, particularly a photosensitive body, is contaminated. It is to provide.

In order to solve the above-mentioned problems, the present inventors have intensively studied, and by using a photosensitive member mainly having a high glass transition point, it is hardly affected by contamination, and has excellent image quality as an electrophotographic apparatus. The present invention has been found out and can be achieved. That is, the gist of the present invention is as follows <1> to <6>.
<1> In an electrophotographic cartridge comprising at least an electrophotographic photosensitive member and charging means for charging the electrophotographic photosensitive member,
The charging means is a charging roller containing a compound represented by the following formula (1):
An electrophotographic process cartridge, wherein a surface transition layer of the electrophotographic photosensitive member has a glass transition point of 85 ° C. or higher and 120 ° C. or lower.

(N represents an integer of 1 to 3)
<2> The electrophotographic process cartridge according to <1>, wherein the charging roller is to be charged by contacting the surface of the electrophotographic photosensitive member.
<3> The electrophotographic process cartridge according to <1> or <2>, wherein the surface layer contains a binder resin, a charge transport material, and an antioxidant.
<4> The surface layer contains a charge transport material, and the content of the charge transport material in the surface layer is 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the binder resin. The electrophotographic process cartridge according to any one of> to <3>.
<5> The electrophotographic process cartridge according to any one of <1> to <4>, wherein the surface layer contains a binder resin having a polysiloxane component.
<6> An image forming apparatus using the electrophotographic process cartridge according to any one of <1> to <5>.

  It is possible to provide an electrophotographic process cartridge capable of stably forming a high-quality electrophotographic image without contaminating the photoconductor even when a conductive roller not subjected to specific processing is brought into contact with the photoconductor for a long time. .

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 1 is an X-ray diffraction pattern of oxytitanium phthalocyanine used in Examples. 1 is an X-ray diffraction pattern of oxytitanium phthalocyanine used in Examples.

  Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of the embodiments of the present invention, and is appropriately modified and implemented without departing from the spirit of the present invention. can do.

≪Electrophotographic photoreceptor≫
The electrophotographic photosensitive member to which this embodiment is applied has a photosensitive layer on a conductive support. As a specific configuration of the photosensitive layer, for example, a charge generation layer mainly composed of a charge generation material and a charge transport layer mainly composed of a charge transport material and a binder resin are laminated on a conductive support. Multilayer type photoreceptors: Dispersion type (single layer type) photoreceptors having a photosensitive layer in which a charge generating material is dispersed in a layer containing a charge transport material and a binder resin on a conductive support. The glass transition point of the surface layer of the photoreceptor is 85 ° C. or higher and 120 ° C. or lower. 90 degreeC or more is preferable from a viewpoint of crack resistance, and 110 degrees C or less is preferable from a viewpoint of coating-film stability. The glass transition point of the surface layer can be adjusted by selecting the structure of the binder resin, the molecular weight of the binder resin, the content of the charge transport material, and the type of additive. When the glass transition point is 85 ° C. or higher, the distribution of low molecules on the surface of the photoreceptor is relatively small, and it is difficult to interact with the low molecules dissolved from the charging roller.

<Conductive support>
There is no particular limitation on the conductive support, but for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel, and conductive powder such as metal, carbon, and tin oxide are added to impart conductivity. A resin material, a resin, glass, paper, or the like on which a conductive material such as aluminum, nickel, or ITO (indium tin oxide) is deposited or applied on the surface is mainly used. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. As a form of the conductive support, a drum form, a sheet form, a belt form or the like is used. Furthermore, a conductive material having an appropriate resistance value may be used on a conductive support made of a metal material in order to control conductivity and surface properties and to cover defects.

Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method.
The support surface may be smooth, or may be roughened by using a special cutting method or by performing a roughening treatment. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without performing the cutting process.

<Underlayer>
In the present invention, the undercoat layer is not essential, but when an undercoat layer is provided, any undercoat layer can be provided. As the undercoat layer, a binder alone can be used, but it is preferable in terms of electrical characteristics and the like to contain an inorganic filler such as metal oxide particles.
As the metal oxide particles, those having high dispersion stability of the coating liquid are preferable, and specific examples include silica, alumina, titanium oxide, barium titanate, zinc oxide, lead oxide, and indium oxide. Among these, metal oxide particles exhibiting n-type semiconductor characteristics are preferable, titanium oxide, zinc oxide, and tin oxide are more preferable, and titanium oxide is most preferable.

Titanium oxide can be either crystalline or amorphous. In the case of crystalline, the crystalline form may be any of anatase type, rutile type or brookite type, but for reasons such as water absorption, surface treatment efficiency, etc. A type or rutile type is generally used. Particularly preferably, a rutile type is used.
As for the particle size of the metal compound particles, those having an average particle size of usually 100 nm or less are preferable, and 10 to 60 nm is particularly preferable, for the reason of dispersion stability in the coating solution. The particle size of the particles used in the coating solution may be uniform or a composite system having different particle sizes. In the case of a composite system having different particle sizes, those having a maximum particle size peak near 150 nm and a particle size distribution with a minimum particle size of about 30 nm to about 500 nm are preferable. And 0.03 μm may be mixed and used. The metal oxide particles are preferably surface-treated with an organometallic compound or the like.

  As the binder resin contained in the undercoat layer, resin materials such as polyvinyl acetal, polyamide resin, phenol resin, polyester, epoxy resin, polyurethane, and polyacrylic acid can be used. Among these, a polyamide resin having excellent adhesion to the support and low solubility in a solvent used in the charge generation layer coating solution is preferable. Among polyamide resins, a copolymer polyamide having a cycloalkane ring structure as a constituent component is preferable, and a copolymer polyamide having a cyclohexane ring structure as a constituent component is more preferable.

The ratio between the metal oxide particles and the binder resin can be arbitrarily selected, but from the viewpoint of liquid stability, coating properties, and electrical characteristics, 0.5 parts by mass to 8 parts by mass with respect to 1 part by mass of the binder resin. The range of parts is preferable, and the range of 2 parts by mass to 5 parts by mass is more preferable.
If the film thickness of the undercoat layer is too thin, the effect on local charging failure will not be sufficient, and conversely if it is too thick, the residual potential will increase or the adhesive strength between the conductive substrate and the photosensitive layer will decrease. Cause. In the present invention, the thickness of the undercoat layer is preferably 0.1 to 20 μm, more preferably 2 to 10 μm, still more preferably 3 to 6 μm.

  In order to obtain an undercoating liquid containing metal oxide particles and a binder resin, a metal oxide treated with a pulverization or dispersion treatment device such as a planetary mill, ball mill, sand mill, bead mill, paint shaker, attritor, or ultrasonic wave. The binder resin or a solution obtained by dissolving the binder resin in an appropriate solvent may be mixed with the product particle slurry, and dissolution and stirring may be performed. On the contrary, the metal oxide particles may be added to the binder resin solution, and pulverization or dispersion treatment may be performed with the dispersing apparatus as described above.

<Photosensitive layer>
As for the type of the photosensitive layer, a charge generation material and a charge transport material are present in the same layer, a single layer type in which the charge generation material is dispersed in the binder resin, and a charge generation layer in which the charge generation material is dispersed in the binder resin. And a functional separation type (laminated type) composed of two layers of a charge transport layer in which a charge transport material is dispersed in a binder resin. As the laminated type photosensitive layer, a charge generation layer and a charge transport layer are laminated in this order from the conductive support side, and a reverse lamination layer in which a charge transport layer and a charge generation layer are laminated in reverse order. Any one of them can be used, but a sequentially laminated photosensitive layer that can exhibit the most balanced photoconductivity is preferable.

[Charge generation layer-stacked type]
The charge generation layer is formed by binding a charge generation material with a binder resin. Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments, but organic photoconductive materials are preferred, especially organic pigments. Is preferred. Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, phthalocyanine pigments or azo pigments are particularly preferable. When organic pigments are used as the charge generating substance, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

  When using a phthalocyanine pigment as a charge generation material, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum or other metal or oxide thereof, halide, water Those having crystal forms of coordinated phthalocyanines such as oxides and alkoxides, and phthalocyanine dimers using oxygen atoms as bridging atoms are used. In particular, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystal types Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, type II, etc. The [mu] -oxo-aluminum phthalocyanine dimer is preferred.

  Among these phthalocyanines, A-type (also known as β-type), B-type (also known as α-type), and powder X-ray diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type and 28.1 ° have the strongest peaks, and 26.2 ° have peaks A hydroxygallium phthalocyanine, G-type μ-oxo-gallium, having a clear peak at 28.1 ° and a half width W of 25.9 ° of 1 ° ≦ W ≦ 0.4 ° A phthalocyanine dimer and the like are particularly preferable.

  The phthalocyanine compound may be a single compound or several mixed or mixed crystal states. As the mixed state that can be put in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or they may be mixed in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, and crystallization. It may be the one that caused the condition. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

The binder resin used in the charge generation layer is not particularly limited, but examples include polyvinyl butyral resin, polyvinyl formal resin, and polyvinyl acetal such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal or acetal. Resin, polyarylate resin, polycarbonate resin, polyester resin, modified ether polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, Polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride-vinegar Vinyl chloride-vinyl acetate copolymer such as vinyl copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer , Styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicon-alkyd resin, phenol-formaldehyde resin and other insulating resins, poly-N-vinylcarbazole, polyvinylanthracene, polyvinylperylene, etc. And organic photoconductive polymers. Any one of these binder resins may be used alone, or two or more thereof may be mixed and used in any combination.

Specifically, for example, the charge generation layer is prepared by dispersing a charge generation material in a solution obtained by dissolving the above-described binder resin in an organic solvent to prepare a coating solution, and applying the coating solution on the conductive support (by applying an undercoat layer). If provided, it is formed by coating (on the undercoat layer).
In the charge generation layer, the compounding ratio (mass) of the binder resin and the charge generation material is usually 10 parts by mass or more, preferably 30 parts by mass or more, and usually 30 parts by mass or more with respect to 100 parts by mass of the binder resin. The range is 1000 parts by mass or less, preferably 500 parts by mass or less, and the film thickness is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less. If the ratio of the charge generation material is too high, the stability of the coating solution may be reduced due to aggregation of the charge generation material, while if the ratio of the charge generation material is too low, the sensitivity as a photoreceptor may be decreased. There is.

  As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or a bead mill dispersion can be used. At this time, it is effective to refine the particles to a particle size in the range of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

[Charge transport layer-stacked type]
The charge transport layer of the multilayer photoconductor contains a charge transport material and usually contains a binder resin and other components used as necessary. The charge transport layer may be composed of a single layer, or may be a stack of a plurality of layers having different constituent components or composition ratios. The film thickness is usually 5 μm to 50 μm, preferably 10 μm to 45 μm.

  The charge transport material is not particularly limited, and any material can be used. Examples of charge transport materials include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron withdrawing materials such as quinone compounds such as diphenoquinone, carbazole derivatives, indoles Derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives and multiple types of these compounds bind Or an electron donating substance such as a polymer having a group consisting of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable. These charge transport materials may be used alone or in combination. Specific examples of suitable structures of the charge transport material are shown below.

  The charge transport layer is formed by binding a charge transport material or the like with a binder resin. As the binder resin, vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof, polycarbonate, polyester, polyester polycarbonate, polysulfone, phenoxy, epoxy, silicone resin, and other thermoplastic resins and various A thermosetting resin etc. are mentioned. Among these resins, a polycarbonate resin or a polyester resin is preferable from the viewpoint of light attenuation characteristics as a photoreceptor and mechanical strength. Specific examples of the repeating structural unit suitable for the binder resin are shown below. These specific examples are shown for illustration, and any known binder resin may be mixed and used as long as it is not contrary to the gist of the present invention, but a resin having a polysiloxane component from the viewpoint of crack resistance. It is preferable to use together.

The viscosity average molecular weight of the binder resin is usually 20,000 or more, preferably 30,000 or more, more preferably 40,000 or more, further preferably 50,000 or more, and photosensitive layer formation from the viewpoint of mechanical strength. From the viewpoint of preparing a coating solution for the above, it is usually 150,000 or less, preferably 120,000 or less, more preferably 100,000 or less.
As a ratio of the whole binder resin and the charge transport material, the charge transport material is usually used at a ratio of 10 parts by mass or more with respect to 100 parts by mass of the binder resin in the same layer. Among these, 20 parts by mass or more is preferable from the viewpoint of reducing the residual potential, and 30 parts by mass or more is more preferable from the viewpoint of stability and charge mobility when repeatedly used. On the other hand, the charge transport material is usually used in an amount of 150 parts by mass or less and a ratio of 120 parts by mass or less from the viewpoint of thermal stability of the photosensitive layer. Among these, 100 parts by mass or less is preferable from the viewpoint of compatibility between the charge transport material and the binder resin, and 80 parts by mass or less is more preferable from the viewpoint of wear resistance.

  Examples of the resin component constituting the resin having a polysiloxane component include vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylate ester resin, methacrylate ester resin, vinyl alcohol resin, and ethyl vinyl ether. Polymers and copolymers, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicone-alkyd resin, poly- N-vinyl carbazole resin and a resin obtained by copolymerizing a plurality of these resins are used. Among these, polycarbonate resin or polyarylate resin is preferable from the viewpoint of mechanical strength. From the viewpoint of dispersibility, among polyester resins, it is preferable to have a structural unit represented by the following formula (1b).

(In the formula (1b), Ar ^{b1 to} Ar ^b4 each independently represent an arylene group which may have a substituent, Z represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group. M represents 0. And represents an integer of 2 or less, and Y represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group.
In said formula (1b), as carbon number of the arylene group in Ar < ^b1 > -Ar < ^b4 >, it is 6 or more normally, and is 20 or less normally, Preferably it is 10 or less, More preferably, it is 6. Specific examples of Ar ^{b1 to} Ar ¹³ include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthylene group, anthrylene group, phenanthrylene group, and the like. Among these, the arylene group is preferably a 1,4-phenylene group from the viewpoint of electrical characteristics. An arylene group may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations. In addition, examples of the substituent that Ar ^{b1 to} Ar ^b4 may have include an alkyl group, an aryl group, a halogen group, and an alkoxy group. Among these, when a polyester resin is used as the binder resin for the photosensitive layer, the alkyl group having 1 to 4 carbon atoms and the carbon number 6 to 12 carbon atoms are considered in consideration of mechanical properties and solubility in the photosensitive layer forming coating solution. An aryl group is preferable, and an alkoxy group having 1 to 4 carbon atoms is also preferable. Specifically, the alkyl group is preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group, the aryl group is preferably a phenyl group or a naphthyl group, and the alkoxy group is a methoxy group, an ethoxy group, a propoxy group, A butoxy group is preferred.

More specifically, Ar ^b3 and Ar ^b4 each independently preferably have a substituent number of 0 or more and 2 or less, more preferably from the viewpoint of adhesiveness, more preferably from the viewpoint of wear resistance. It is particularly preferable that the number of groups is one. Moreover, as a substituent, an alkyl group is preferable and a methyl group is particularly preferable. From the viewpoints of electrical properties and wear resistance, when s is 0 in the formula (1b), Ar ^b3 and Ar ^b4 are preferably arylene groups having an alkyl group. On the other hand, Ar ^b1 and Ar ^b2 each independently preferably have 0 or more and 2 or less substituents, and more preferably have no substituents from the viewpoint of wear resistance.

In the above formula (1b), Y is a single bond, an oxygen atom, a sulfur atom or an alkylene group. As the alkylene group, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —, and cyclohexylene are preferable, and —CH ₂ —, —CH (CH ₃ ) —, — are more preferable. C _{(CH 3) 2} - a. In the formula (1b), Z is a single bond, an oxygen atom, a sulfur atom or an alkylene group, and among them, Z is preferably an oxygen atom. In this case, s is preferably 0 or 1, and particularly preferably 1.

Specific examples of the dicarboxylic acid residue which is a structural unit represented by the formula (1b) when m is 1 include diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,3′-dicarboxylic acid Residue, diphenyl ether-2,4′-dicarboxylic acid residue, diphenyl ether-3,3′-dicarboxylic acid residue, diphenyl ether-3,4′-dicarboxylic acid residue, diphenyl ether-4,4′-dicarboxylic acid residue Etc. Among these, considering the simplicity of production of the dicarboxylic acid component, diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,4′-dicarboxylic acid residue, diphenyl ether-4,4′-dicarboxylic acid Residues are more preferred, and diphenyl ether-4,4′-dicarboxylic acid residues are particularly preferred. Specific examples of dicarboxylic acid residues when m is 0 include phthalic acid residues, isophthalic acid residues, terephthalic acid residues, toluene-2,5-dicarboxylic acid residues, p-xylene-2,5- Dicarboxylic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,3-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2′-dicarboxylic acid residue, Biphenyl-4,4'-dicarboxylic acid residue is mentioned. Preferably, phthalic acid residue, isophthalic acid residue, terephthalic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2′-dicarboxylic acid residue Group, biphenyl-4,4′-dicarboxylic acid residue, particularly preferably an isophthalic acid residue or a terephthalic acid residue. It is also possible to use a combination of these dicarboxylic acid residues.
From the viewpoint of electrical characteristics, among polycarbonate resins, it is preferable to have a structural unit represented by the following formula (2b).

(In the general formula (2b), the substituents R ^b1 and R ^b2 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the substituents may be bonded to form a ring. R ^b3 and R ^b4 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, W represents a single bond, an oxygen atom, or —CR ^b5 R ^b6 —, and the substituents R ^b5 and R ^b6 independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, provided that t and u units have different structures.)

The carbon number of the alkyl group is usually 8 or less, preferably 6 or less, and more preferably 3 or less. Specific examples of the alkyl group include linear alkyl groups such as a methyl group, an ethyl group, and a propyl group, branched alkyl groups such as an isopropyl group, a tert-butyl group, and an isobutyl group, a cyclohexyl group, and a cyclopentyl group. A cyclic alkyl group can be mentioned, and among these, a methyl group is particularly preferable from the viewpoint of synthesis. Further, the substituents may be bonded to each other to form a ring. The carbon number of the aryl group is usually 30 or less, preferably 20 or less, and more preferably 15 or less. Specific examples include a phenyl group, a naphthyl group, an anthranyl group, a pyrenyl group, etc., a phenyl group or a naphthyl group is preferable from the viewpoint of synthesis, a naphthyl group is particularly preferable from the viewpoint of crack resistance, and ease of production. From this viewpoint, a phenyl group is particularly preferable. Specific examples of suitable structures are shown below.

As the configuration of the resin having a polysiloxane component, the configuration of a resin having a known polysiloxane can be used. For example, if the resin component is A and the polysiloxane component is B, A-B (block copolymer having a polysiloxane component at one end), B-A-B (block having a polysiloxane component at both ends) Copolymer), A-B-A (block copolymer having a resin component on both sides of the polysiloxane component), A-A (-B) -A (polysiloxane component is branched from the main chain resin) Block copolymer). One of these or a combination of a plurality of components may be used.
The polysiloxane structure is preferably a structure represented by the following general formula (3b), a diol component represented by the following general formula (5b), or the following general formula (6b).

(In the general formula (3b), W ² represents a single bond, O, CO, COO, NH, NHCO, S, SO, SO 2, and Y represents a divalent group containing at least one of aliphatic and aromatic. R ^{b7 to} R ^b9 represent an organic group, at least one of which is a siloxane group represented by the following general formula (4b), the rest being an alkyl group having 1 to 10 carbon atoms, and an alkenyl having 3 to 10 carbon atoms A group, a halogen, a halogenated alkyl group, an alkoxyl group, or an aryl group which may have a substituent.

(In General Formula (4b), R ^{b10 to} R ^b11 represent an alkyl group or an aryl group, and n represents an integer of 1 to 500.

(In General Formula (5b), R ^{b13 to} R ^b14 each independently represents an alkyl group which may have a substituent, an aryl group which may have a substituent, or Formula (3b), p and q each independently represents an integer of 0 to 500.)

(In General Formula (6b), R ^{b17 to} R ^b23 each independently represents an alkyl group or an aryl group which may have a substituent, and R ^b24 represents an alkyl group which may have a substituent. Represents an aryl group which may have a substituent or formula (4b), and f to j each independently represents an integer of 0 to 500.)
The ratio (mol%) of the material amount of the bisphenol component represented by the general formula (4b) or the general formula (5b) contained in one molecule of the resin component is not particularly affected unless the effect of the present invention is significantly affected. Although not limited, it is usually 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less, and particularly preferably 5 mol% or less. Moreover, it is 0.001 mol% or more normally, Preferably it is 0.01 mol% or more, More preferably, it is 0.05 mol% or more. The mass ratio (wt%) of the bisphenol component represented by the general formula (4b) or general formula (5b) contained in one molecule is not particularly limited as long as it does not significantly affect the effect of the present invention. Usually, it is 30 wt% or less, preferably 20 wt% or less, more preferably 10 wt% or less. Moreover, it is 0.01 wt% or more normally, Preferably it is 0.05 wt% or more, More preferably, it is 0.1 wt% or more.

The ratio of the polysiloxane structure in the resin having a polysiloxane structure is usually 10% by mass or less, and preferably 7% by mass or less. Usually, it is 0.1% by mass or more, preferably 0.2% by mass or more.
The viscosity average molecular weight of the resin having a polysiloxane component is arbitrary as long as the effects of the present invention are not significantly impaired, but from the viewpoint of wear resistance, it is preferably 5,000 or more, more preferably 10,000 or more. . Moreover, from a viewpoint of the solubility to a solvent and productivity, Preferably it is 100,000 or less, More preferably, it is 90,000 or less. In addition, a viscosity average molecular weight can be measured by the method as described in an Example using an Ubbelohde type capillary viscometer etc., for example.

  The compounding ratio (mass) of the resin having the polysiloxane component and the other binder resin in the total binder resin in the photosensitive layer is usually 2 for the resin having the polysiloxane component with respect to 100 parts by mass of the total binder resin. It is preferably 4 parts by mass or more from the viewpoint of surface slipperiness or more by mass part. From the viewpoints of wear resistance and surface mechanical properties, it is usually 90 parts by mass or less, preferably 50 parts by mass or less, more preferably 30 parts by mass or less.

  The binder resin other than the resin having a polysiloxane component in all the binder resins is not particularly limited as long as it is soluble in an organic solvent used for the photosensitive layer forming coating solution. Examples of binder resins other than resins having a polysiloxane component include polyvinyl butyral resins, polyvinyl formal resins, and polyvinyl acetal resins such as partially acetalized polyvinyl butyral resins in which a part of butyral is modified with formal or acetal. , Polycarbonate resin, polyester resin, modified ether-based polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, polyamide resin, polyvinyl pyridine resin , Cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, casein, vinyl chloride-vinyl acetate copolymer, Roxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, etc., vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer Insulating resins such as polymers, vinylidene chloride-acrylonitrile copolymers, styrene-alkyd resins, silicon-alkyd resins, phenol-formaldehyde resins, and organic photoconductive materials such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylperylene. The polymer can be selected and used, but is not limited to these polymers. These binder resins may be used alone or in combination of two or more. Among these, from the viewpoint of improving the elastic deformation rate, a polycarbonate resin and a polyester resin are preferably used. From the viewpoint of suppressing fogging, among the polyester resins, a resin having a structural unit represented by the formula (1b) is preferable.

The viscosity average molecular weight of the binder resin other than the resin having a polysiloxane component is arbitrary as long as the effects of the present invention are not significantly impaired. From the viewpoint of mechanical strength, it is usually 20,000 or more, preferably 30,000 or more. More preferably, it is 40,000 or more. Further, from the viewpoint of productivity such as the dispersibility of the compound and the viscosity of the coating solution, it is usually 100,000 or less, preferably 9
It is not more than 10,000, more preferably not more than 80,000. The viscosity average molecular weight can be measured by a known method using, for example, an Ubbelohde capillary viscometer.

The thickness of the charge transport layer is not particularly limited, but from the viewpoint of electrical characteristics and image stability, and from the viewpoint of high resolution, it is usually preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 35 μm or less, and still more preferably. 15 μm or more and 25 μm or less.
In order to improve the film forming property, flexibility, coating property, stain resistance, gas resistance, light resistance, etc. in the charge transport layer, or to further improve the mechanical strength of the photosensitive layer, a well-known plasticizer, It is also preferable to add additives such as a lubricant, a dispersion aid, an antioxidant, an ultraviolet absorber, an electron-withdrawing compound, a dye, a pigment, a sensitizer, a leveling agent, a stabilizer, a fluidity-imparting agent, and a crosslinking agent. . Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. Examples of dyes and pigments include various pigment compounds and azo compounds. Examples of leveling agents include silicone oil and fluorine-based surfactants.

  Electron-withdrawing compounds include tetracyanoquinodimethane, dicyanoquinomethane, cyano compounds such as aromatic esters having a dicyanoquinovinyl group, nitro compounds such as 2,4,6-trinitrofluorenone, and condensation of perylene. Polycyclic aromatic compounds, diphenoquinone derivatives, quinones, aldehydes, ketones, esters, acid anhydrides, phthalides, metal complexes of substituted and unsubstituted salicylic acid, metal salts of substituted and unsubstituted salicylic acid, aromatic carboxylic acids And metal salts of aromatic carboxylic acids. Preferably, cyanide compounds, nitro compounds, condensed polycyclic aromatic compounds, diphenoquinone derivatives, metal complexes of substituted and unsubstituted salicylic acid, metal salts of substituted and unsubstituted salicylic acid, metal complexes of aromatic carboxylic acid, aromatic carboxylic acid Metal salts are used.

<Method for forming each layer>
Each layer constituting the photoreceptor is formed by immersing, coating, spraying, nozzle coating, bar coating, roll coating, blade coating, etc., on a support, a coating solution obtained by dissolving or dispersing a substance contained in each layer in a solvent. In this method, the coating and drying steps are sequentially repeated for each layer.
Although there is no particular limitation on the solvent or dispersion medium used for the production of the photosensitive layer, specific examples include ethers such as tetrahydrofuran, 1,4-dioxane and dimethoxyethane, esters such as methyl formate and ethyl acetate, acetone, Ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene and xylene, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, Chlorinated hydrocarbons such as 1,2-dichloropropane and trichloroethylene, nitrogen-containing compounds such as n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine and triethylenediamine, acetonitrile, and N-methylpyrrolide , N, N- dimethylformamide, aprotic polar solvents such as dimethyl sulfoxide and the like. Moreover, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and kinds.

The amount of the solvent or dispersion medium used is not particularly limited, but considering the purpose of each layer and the properties of the selected solvent / dispersion medium, it is appropriate so that the physical properties such as solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to adjust.
In the case of the charge transport layer, the solid content concentration of the coating solution is usually 5% by mass or more, preferably 10% by mass or more, and usually 40% by mass or less, preferably 35% by mass or less. Further, the viscosity of the coating solution is usually in the range of 10 cps or more, preferably 50 cps or more, and usually 500 cps or less, preferably 400 cps or less.

In the case of the charge generation layer, the solid content concentration of the coating solution is usually 0.1% by mass or more, preferably 1
It is made into the range of the mass% or more, and 15 mass% or less normally, Preferably it is 10 mass% or less. The viscosity of the coating solution is usually 0.01 cps or more, preferably 0.1 cps or more, and usually 20 cps or less, preferably 10 cps or less.
Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.

≪Image forming device≫
An image forming apparatus such as a copying machine or a printer using the electrophotographic photosensitive member of the present invention includes at least charging, exposure, development, transfer, and cleaning processes. Also good.
As a charging method (charging machine), a charging roller containing a compound represented by the following formula (1) is used. A direct charging means for charging a direct charging member to which a voltage is applied by contacting the surface of the photosensitive member is preferable. As the charging method, DC charging or AC superimposed DC charging can be used.

  The rubber component contained in the charging roller includes diene rubber and hydrogenated products thereof (for example, natural rubber (NR), isoprene rubber (IR), epoxidized NR, styrene-butadiene rubber (SBR), butadiene rubber (BR ( High cis BR and low cis BR)), acrylonitrile-butadiene rubber (NBR), hydrogenated NBR, hydrogenated SBR, olefinic rubber (eg, ethylene-propylene rubber (EPDM, EPM), maleic acid-modified ethylene-propylene rubber) (M-EPM)), butyl rubber (IIR), isobutylene and aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), halogen-containing rubber (for example, Br-IIR, Cl-IIR, isobutylene-paramethylstyrene) Copolymer bromide (Br-IPMS), Chlorop Wren rubber (CR), epichlorohydrin rubber (CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid modified chlorinated polyethylene (M-CM)), alkyl ether rubber, silicone rubber (for example, methyl vinyl) Silicone rubber, dimethyl silicone rubber, methylphenyl vinyl silicone rubber), sulfur-containing rubber (for example, polysulfide rubber), fluorine rubber (for example, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing rubber) Silicone rubber, fluorine-containing phosphazene rubber), etc. After adding a compounding agent to these, vulcanized rubber is obtained by means such as heating.

In order to obtain conductivity, the conductive rubber such as carbon black, zinc oxide, tin oxide and titanium oxide mixed with raw material rubber, ion conductive rubber such as acrylonitrile butadiene rubber and epichlorohydrin rubber. Conductive rubber may be used, and if necessary, an ionic conductive agent such as alkali metal perchlorate, long-chain alkyl sulfonate and tetraalkyl quaternary ammonium salt may be mixed in the ionic conductive rubber. Good. However, it is preferable not to use an ionic conductive agent in terms of bridging and blooming. Moreover, it is preferable to use an ion conductive rubber from the viewpoint of easy control of conductivity, and it is preferable to use acrylonitrile butadiene rubber, epichlorohydrin rubber or alkyl ether rubber from the viewpoint of processability.
As a low molecular component additive contained in the charging roller, a compound represented by the following formula (1) is contained.

  The compound represented by the formula (1) acts as an anti-aging agent. As a specific example, “NOCRACK NS-5” (trade name, manufactured by Ouchi Shinsei Chemical Co., Ltd.) or the like is used. The addition amount is preferably set to 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the polymer elastic body (rubber component) from the viewpoint of flexibility of the conductive elastic body. In addition to these, additives such as a plasticizer, a softening agent, an anti-aging agent, and a vulcanization accelerator may be contained. Examples of petroleum softeners include paraffinic, naphthenic and aromatic process oils. Plant softeners include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, wax, rosin, pine oil, tall oil and the like. Examples of the plasticizer include adipate plasticizers such as dioctyl adipate (DOA), diisodecyl adipate (DIDA), dibutyl glycol adipate, and dibutylbitol adipate. Sebacate plasticizers such as dioctyl sebacate (DOS) and dibutyl sebacate (DBP), tricresyl phosphate (TCP) cresyl phenyl phosphate (CDP), tributyl phosphate (TBP), trioctyl phosphate (TOP) ), Phosphate plasticizers such as tributoxyethyl phosphate (TBXP), polyether plasticizers, and polyester plasticizers. The addition amount of these plasticizers is preferably set to 5 parts by mass or more and 400 parts by mass or less with respect to 100 parts by mass of the polymer elastic body (rubber component) from the viewpoint of the flexibility of the charging roller. Particularly preferably, it is 10 parts by mass or more and 300 parts by mass or less.

  Examples of vulcanizing agents include dibenzothiazyl sulfide “Noxeller DM-P” (trade name, manufactured by Ouchi Shinsei Chemical Co., Ltd.), tetramethylthiuram monosulfide “Noxeller TS” manufactured by Ouchi Shinsei Chemical Industries Co., Ltd.) , And sulfur (manufactured by Tsurumi Chemical Co., Ltd.) can be used. When these additives flow out from the charging roller and come into contact with the photoreceptor, the surface of the photoreceptor may be contaminated.

  As the exposure light, halogen lamps, fluorescent lamps, lasers (semiconductors, He—Ne), LEDs, photoconductor internal exposure systems, and the like are used. As digital electrophotographic systems, lasers, LEDs, optical shutter arrays, and the like are used. preferable. As the wavelength, in addition to monochromatic light of 780 nm, monochromatic light near a short wavelength in the 600 to 700 nm region and short wavelength monochromatic light in the 380 to 500 nm region can be used.

As the toner, in addition to the pulverized toner, a polymerized toner such as suspension polymerization or emulsion polymerization aggregation method can be used. In particular, in the case of the polymerized toner, those having a small particle diameter of about 4 to 8 μm in average diameter are used, and those having a shape close to a spherical shape or those outside a potato-like spherical shape can be used. The polymerized toner is excellent in charging uniformity and transferability and is suitably used for high image quality.
For the transfer step, electrostatic transfer methods such as corona transfer, roller transfer, and belt transfer, pressure transfer methods, and adhesive transfer methods are used. For fixing, heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like is used.

For cleaning, brush cleaner, magnetic brush cleaner, electrostatic brush cleaner, magnetic roller cleaner, blade cleaner, etc. are used.
In many cases, the static elimination step is omitted, but when used, a fluorescent lamp, LED, or the like is used, and an exposure energy that is three times or more of the exposure light is often used as the intensity. In addition to these processes, a pre-exposure process and an auxiliary charging process may be included.

An embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.
As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.

The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are disposed along the outer peripheral surface of the electrophotographic photosensitive member 1.
The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2, but other corona charging devices such as corotron and scorotron, and contact-type charging devices such as charging brushes are often used.

  In many cases, the electrophotographic photosensitive member 1 and the charging device 2 are designed to be removable from the main body of the image forming apparatus as a cartridge including both of them (hereinafter also referred to as a photosensitive cartridge). For example, when the electrophotographic photoreceptor 1 or the charging device 2 deteriorates, the photoreceptor cartridge can be removed from the image forming apparatus main body, and another new photosensitive cartridge can be mounted on the image forming apparatus main body. ing. Also, the toner described later is often stored in the toner cartridge and designed to be removable from the main body of the image forming apparatus. When the toner in the used toner cartridge runs out, this toner cartridge is removed. It can be removed from the main body of the image forming apparatus and another new toner cartridge can be mounted. Further, a cartridge equipped with all of the electrophotographic photosensitive member 1, the charging device 2, and the toner may be used.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a short wavelength of 380 nm to 500 nm. .

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component conductive toner development, two-component magnetic brush development, or a wet development method can be used. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like that are disposed to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  The cleaning device 6 is not particularly limited, and any cleaning device such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, or a blade cleaner can be used. However, the present invention is effective for a blade cleaner. Is easy to demonstrate. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1. The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.

  When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6. After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.

  In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

  The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.

<Manufacture of coating liquid for undercoat layer formation>
Coating liquid A
A rutile type titanium oxide having an average primary particle diameter of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by mass of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were added to a Henschel mixer. 1 kg of a raw slurry obtained by mixing 50 parts of surface-treated titanium oxide obtained by mixing with 120 parts of methanol, and using a zirconia bead having a diameter of about 100 μm (YTZ manufactured by Nikkato Co., Ltd.) as a dispersion medium, a mill volume of about 0 Using a 15-liter Ultra Apex Mill (UAM-015 type) manufactured by Kotobuki Kogyo Co., Ltd., a titanium oxide dispersion was prepared by dispersing for 1 hour in a liquid circulation state with a rotor peripheral speed of 10 m / second and a liquid flow rate of 10 kg / hour. .

The titanium oxide dispersion, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula Compound represented by (B)] / hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [following formula (E ) And a copolymerized polyamide pellet having a composition molar ratio of 75% / 9.5% / 3% / 9.5% / 3% while stirring and mixing the mixture to obtain polyamide pellets. After dissolution, ultrasonic dispersion with an ultrasonic transmitter with an output of 1200 W is performed for 1 hour, and a PTFE membrane filter (a) with a pore size of 5 μm is added. The mixture was filtered through Dovetec Mytecs LC), and the mass ratio of the surface-treated titanium oxide / copolymerized polyamide was 3/1, and the mass ratio of the mixed solvent of methanol / 1-propanol / toluene was 7/1/2. Thus, an undercoat layer-forming coating solution A having a solid content concentration of 18.0% by mass was obtained.

<Manufacture of coating solution for forming charge generation layer>
Charge generation layer forming coating solution B
The charge generation layer forming coating solution was prepared as follows. As a charge generation substance, 20 parts of oxytitanium phthalocyanine shown in the X-ray diffraction spectrum of FIG. 2 and 280 parts of 1,2-dimethoxyethane were mixed, and pulverized with a sand grind mill for 1 hour for atomization dispersion treatment. Subsequently, 10 parts of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) were added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-. A binder liquid obtained by dissolving in 85 parts of a mixed solution of methyl-2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution B1 for forming a charge generation layer.

As a charge generation material, 20 parts of oxytitanium phthalocyanine shown in the X-ray diffraction spectrum of FIG. 3 and 280 parts of 1,2-dimethoxyethane were mixed and pulverized with a sand grind mill for 4 hours for atomization dispersion treatment. Subsequently, 10 parts of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) were added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-. A binder solution obtained by dissolving in 85 parts of a mixture of methyl-2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a charge generation layer forming coating solution B2.
The charge generation layer forming coating solution B1 and the charge generation layer forming coating solution B2 were mixed at a ratio of 6: 4 to prepare the charge generation layer forming coating solution B used in this example.

<Manufacture of coating liquid for charge transport layer formation>
Charge transport layer forming coating solution C1
85.7 parts of polycarbonate resin represented by the following repeating structure (resin X1, viscosity average molecular weight 40,000), and 14.3 parts of resin having a polysiloxane structure (resin XE1, viscosity average molecular weight 23,000), charge 40 parts of CTM1 as a transport material, 4 parts of compound AD1 represented by the following formula, 0.05 part of a leveling agent silicone oil (Shin-Etsu Chemical KF96-10CS) are dissolved by heating with a tetrahydrofuran solvent to dissolve the solid content. A coating solution C1 for forming a charge transport layer having a concentration of 20% by mass was obtained.

Coating liquid C2
A charge transport layer forming coating solution C2 was prepared in the same manner as C1, except that CTM2 was used instead of CTM1 used for the charge transport layer forming coating solution C1.

Coating liquid C3
Instead of the X1 and XE1 resins used for the charge transport layer forming coating solution C1, 50 parts of a polycarbonate resin represented by the following repeating structure (resin Y1, viscosity average molecular weight 40,000), and the same polycarbonate resin 29.3 For charge transport layer formation in the same manner as C1, except that 20.7 parts of resin (resin Y2, viscosity average molecular weight 40,000) and 20.7 parts of resin having a polysiloxane structure (resin YE1, viscosity average molecular weight 49,600) were used. A coating liquid C3 was prepared.

Coating liquid C4
A charge transport layer forming coating solution C4 was prepared in the same manner as C3, except that the number of parts of CTM1 used in the charge transport layer forming coating solution C3 was changed to 30 parts.
Coating liquid C5
Instead of the Y1 and Y2 resins used in the charge transport layer forming coating solution C3, 50 parts of a polycarbonate resin represented by the following repeating structure (resin Z1, viscosity average molecular weight 50,000),
Similarly, charge transport layer forming coating solution C5 was prepared in the same manner as C3, except that 29.3 parts of polycarbonate resin (resin Z2, viscosity average molecular weight 40,000) was used.

Coating liquid C6
A charge transport layer forming coating solution C6 was prepared in the same manner as C1, except that the number of parts of CTM1 used in the charge transport layer forming coating solution C1 was 75 parts.
Coating liquid C7
A charge transport layer forming coating solution C7 was prepared in the same manner as C3, except that CTM1 used in the charge transport layer forming coating solution C3 was CTM2 represented by the following structure and the number of parts was 75 parts.

<Manufacture of photosensitive drum>
Hereinafter, using the coating liquid, as shown in Table 1, photosensitive drums corresponding to Examples 1 to 5 and Comparative Examples 1 and 2 were produced as follows. A coating solution for forming an undercoat layer, a coating solution for forming a charge generation layer, prepared in a manufacturing example of a coating solution on a cylinder made of an aluminum alloy having an outer diameter of 24 mm, a length of 248 mm, and a wall thickness of 0.75 mm. The coating solution for forming the charge transport layer is sequentially applied and dried by a dip coating method, and the undercoat layer, the charge generation layer, and the charge transport are adjusted so that the film thicknesses after drying are 1.5 μm, 0.5 μm, and 23 μm, respectively. A layer was formed to produce a photoreceptor drum. The charge transport layer was dried at 125 ° C. for 24 minutes.

<Measurement of glass transition point>
The glass transition temperature (° C.) of the surface layer of the photosensitive layer was measured under the following conditions by differential thermal analysis (DSC).
Device name: DSC-60 manufactured by Shimadzu
Temperature range: room temperature to 150 ° C
Temperature increase rate: 10 ° C / min
Atmosphere: N ₂ flow 50 ml / min
The sample was heated once and measured (1st-run), then rapidly cooled with liquefied nitrogen, and again heated and measured (2nd-run).
In the analysis, the midpoint temperature was taken as the glass transition point (glass transition point).

<Crack test>
The obtained photoreceptor was mounted on a cartridge D205E for monochrome printer ML3710 manufactured by Samsung. The charging roller used a mixture of the following formula (1) as an anti-aging agent. It was left at 55 ° C. for 4 weeks, and after that, black solids and halftones were printed with the printer, and it was confirmed whether or not white streaks entered the contact portion with the charging roll. The results are shown in Table-1.

(N represents 1, 2, or 3)
Evaluation standard ◎: No white streak is seen at all ○: White streak is hardly seen △: White streak is seen a little ×: White streak is clearly confirmed

  It can be seen that a crack having a higher glass transition point is superior. The glass transition point is higher when the resin X1 is used, the CTM is higher when the CTM2 is used, and the number of parts is lower. It can be seen that the effect of suppressing cracking under high temperature conditions can be obtained only when a charging roller containing a photoconductor having a specific glass transition point and a specific compound is used.

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
DESCRIPTION OF SYMBOLS 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (6)

In an electrophotographic cartridge comprising at least an electrophotographic photosensitive member and charging means for charging the electrophotographic photosensitive member,
The charging means is a charging roller containing a compound represented by the following formula (1):
An electrophotographic process cartridge, wherein a surface transition layer of the electrophotographic photosensitive member has a glass transition point of 85 ° C. or higher and 120 ° C. or lower.

(N represents an integer of 1 to 3)   The electrophotographic process cartridge according to claim 1, wherein the charging roller is brought into contact with the surface of the electrophotographic photosensitive member to be charged.   The electrophotographic process cartridge according to claim 1, wherein the surface layer contains a binder resin, a charge transport material, and an antioxidant.   The surface layer contains a charge transport material, and the content of the charge transport material in the surface layer is 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the binder resin. The electrophotographic process cartridge according to any one of the above.   The electrophotographic process cartridge according to claim 1, wherein the surface layer contains a binder resin having a polysiloxane component.   An image forming apparatus using the electrophotographic process cartridge according to claim 1.

Images