JP2016139135A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor such that abutting force of a space holding member to the electrophotographic photoreceptor is high and a photosensitive layer of the electrophotographic receptor is suppressed from peeling against long-period repetitive use, a process cartridge and an electrophotographic device.SOLUTION: There are provided a process cartridge and an electrophotographic device that have: a first region where a base, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer are formed in this order; and a second region where the base, second intermediate layer, charge generation layer, and surface layer are formed in this order, or where the base, charge generation layer, and surface layer are formed in this order, or where the surface layer provided on the base is formed. An electrification member abuts on the first region of the electrophotographic receptor, and at least one of space holding members provided on both outer sides of a developer carrier abuts on the second region of the electrophotographic receptor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge having an electrophotographic photosensitive member, and an electrophotographic apparatus.

  The electrophotographic photosensitive member is mounted on a process cartridge or an electrophotographic apparatus, and has a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and the like around it. Image formation is carried out through steps by these plural means, and the surface layer of the photoconductor is damaged and worn due to sliding and contact forces with several peripheral members in those steps.

  In recent years, there has been a demand for a process cartridge and an electrophotographic apparatus having a higher speed and a longer life, and an improvement in the stability of the electrophotographic photosensitive member over a long period is desired. In order to cope with this, a technique for suppressing positive ghost over a long period of time by containing a polymer of a composition containing an electron transport material and a crosslinking agent in the undercoat layer of the electrophotographic photosensitive member is disclosed ( Patent Document 1).

  On the other hand, as process cartridges and electrophotographic devices increase in speed and service life, damage and wear due to friction and contact force with peripheral members that contact the surface layer of the photoreceptor increase, and the durability of the surface layer increases. The problem becomes more apparent. In particular, damage to the photoconductor caused by receiving a contact force from a member (interval holding member) for maintaining (regulating) the interval with the photoconductor used in the developing means is large, and repeated use over a longer period of time. In this case, the surface layer of the photoreceptor may be peeled off.

  Conventionally, in an electrophotographic photoreceptor, an undercoat layer is often provided in order to increase the adhesive force between the conductive substrate and the photosensitive layer. However, even when the undercoat layer is provided, there is a problem that the film of the photosensitive layer is peeled off from the end of the photosensitive layer. Therefore, Patent Document 2 describes a technique for forming a photosensitive layer inside the end portion of the undercoat layer.

  However, when an undercoat layer containing metal oxide particles is used, the exposed undercoat layer receives the rubbing and contact force with the peripheral member, so that the metal oxide particles present on the surface of the undercoat layer Peels off and contaminates the surface layer and peripheral members of the photoreceptor. Therefore, Patent Document 3 describes a technique for forming a photosensitive layer so as to cover the undercoat layer.

JP 2014-29480 A JP 59-184359 A JP 2002-107986 A

  As a result of investigations by the present inventors, referring to the layer structure described in Patent Document 3, the undercoat layer of the electrophotographic photosensitive member contains a polymer of a composition containing an electron transport material and a crosslinking agent. In some cases, we found that: That is, the photosensitive layer may be peeled off at the portion where the spacing member and the photosensitive member abut. In particular, it has been found that there is room for improving the problem of peeling of the photosensitive layer under the condition that the contact force of the spacing member with respect to the photosensitive member is higher and long-term paper passing durability is required.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member, a process cartridge, and an electronic device in which the contact force of the spacing member with respect to the photosensitive member is higher and peeling of the photosensitive layer can be suppressed even after repeated use over a long period of time. It is to provide a photographic apparatus.

The present invention is a process cartridge configured to be detachable from an electrophotographic apparatus main body, and the process cartridge includes:
Cylindrical electrophotographic photoreceptor,
A developer carrying member for supplying a developer to the electrophotographic photosensitive member, a first spacing member that contacts the electrophotographic photosensitive member and holds a gap between the developer carrying member and the electrophotographic photosensitive member; A second spacing member, and
A charging member that contacts the electrophotographic photosensitive member and charges the electrophotographic photosensitive member;
The first spacing member and the second spacing member are provided at positions outside the both ends of the charging member along the generatrix direction of the electrophotographic photosensitive member,
The electrophotographic photoreceptor is
A first region having a support, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(I) a region having a support, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(Ii) a region having a support, a charge generation layer, and a surface layer in this order; and
(Iii) a support, a second region selected from a region having a surface layer provided on the support in this order;
Have
The first intermediate layer contains metal oxide particles and a phenol resin,
The second intermediate layer contains a polymer of a composition comprising an electron transport material and a crosslinking agent;
The charge generation layer contains a thermoplastic resin;
The charging member is in contact with the surface of the first region of the electrophotographic photosensitive member;
The present invention relates to a process cartridge, wherein the first spacing member is in contact with the surface of the second region of the electrophotographic photosensitive member.

Furthermore, the present invention provides
A cylindrical electrophotographic photosensitive member, a developer carrying member for supplying a developer to the electrophotographic photosensitive member, and the electrophotographic photosensitive member abutting the gap between the developer carrying member and the electrophotographic photosensitive member A first spacing member and a second spacing member to be held, and
A charging member that contacts the electrophotographic photosensitive member and charges the electrophotographic photosensitive member;
An electrophotographic apparatus comprising:
The first spacing member and the second spacing member are provided at positions outside the both ends of the charging member along the generatrix direction of the electrophotographic photosensitive member,
The electrophotographic photoreceptor is
A first region having a support, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(I) a region having a support, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(Ii) a region having a support, a charge generation layer, and a surface layer in this order; and
(Iii) a support, a second region selected from a region having a surface layer provided on the support in this order;
Have
The first intermediate layer contains metal oxide particles and a phenol resin,
The second intermediate layer contains a polymer of a composition comprising an electron transport material and a crosslinking agent;
The charge generation layer contains a thermoplastic resin;
The charging member is in contact with the surface of the first region of the electrophotographic photosensitive member;
The electrophotographic apparatus according to claim 1, wherein the first spacing member is in contact with the surface of the second region of the electrophotographic photosensitive member.

  According to the present invention, an electrophotographic photosensitive member, a process cartridge, and an electronic device in which the contact force of the spacing member with respect to the photosensitive member is higher and peeling of the photosensitive layer can be suppressed even after repeated use over a long period of time. A photographic device can be provided.

1 is a diagram illustrating a schematic configuration of an electrophotographic apparatus having a process cartridge including an electrophotographic photosensitive member. It is a figure which shows an example of the layer structure in the edge part area | region of an electrophotographic photoreceptor. It is a figure explaining the relationship between an electrophotographic photoreceptor and a spacing member.

The process cartridge of the present invention is configured to be detachable from the electrophotographic apparatus main body. The process cartridge includes a cylindrical electrophotographic photosensitive member, a developer carrying member for supplying a developer to the electrophotographic photosensitive member, and the electrophotographic photosensitive member in contact with the developer carrying member and the electrophotographic photosensitive member. And a charging member that contacts the electrophotographic photosensitive member and charges the electrophotographic photosensitive member. The first spacing member and the second spacing member are provided at positions outside the both ends of the charging member along the generatrix direction of the electrophotographic photosensitive member. A first region in which the electrophotographic photoreceptor has a support, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(I) a region having a support, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(Ii) a region having a support, a charge generation layer, and a surface layer in this order; and
(Iii) a support, and a second region selected from a region having a surface layer provided on the support in this order. The charging member is in contact with the surface of the first region of the electrophotographic photosensitive member, and the first spacing member is in contact with the surface of the second region of the electrophotographic photosensitive member.
The first intermediate layer contains metal oxide particles and a phenol resin, the second intermediate layer contains a polymer of a composition containing an electron transport material and a crosslinking agent, and the charge generation layer is a thermoplastic resin. Containing.

  Further, the electrophotographic apparatus of the present invention comprises a cylindrical electrophotographic photosensitive member, a developer carrier for supplying a developer to the electrophotographic photosensitive member, and abutting the electrophotographic photosensitive member, the developer carrier and the electrophotographic photosensitive member A first interval holding member and a second interval holding member for holding an interval from the electrophotographic photosensitive member; and a charging member which contacts the electrophotographic photosensitive member and charges the electrophotographic photosensitive member. The electrophotographic photosensitive member, the first interval holding member, the second interval holding member, and the charging member are as described above with respect to the respective relationships.

  The layer structure of the electrophotographic photosensitive member according to the present invention will be described below. The electrophotographic photoreceptor according to the present invention includes a support (conductive support), a first intermediate layer formed on the support, a second intermediate layer on the first intermediate layer, and charge generation on the second intermediate layer. An electrophotographic photosensitive member having a layer and a surface layer (charge transport layer). The photosensitive layer is preferably a laminated type (functional separation type) photosensitive layer separated into a charge generation layer having a charge generation material and a charge transport layer containing a charge transport material.

  FIG. 2 is a diagram showing an example of a layer structure in the end region of the electrophotographic photosensitive member. As shown in FIG. 2, the first intermediate layer 102 provided on the support 101, the second intermediate layer 103 provided on the first intermediate layer 102, and the charge generation layer provided on the second intermediate layer 103 104, a first region having a surface layer 105 provided on the charge generation layer 104. Then, a second region having a second intermediate layer 103 provided on the support 101, a charge generation layer 104 provided on the second intermediate layer 103, and a surface layer 105 provided on the charge generation layer 104 is formed. Have.

[Support]
As a support body, what has electroconductivity (conductive support body) is preferable. For example, a support made of a metal such as aluminum, iron, nickel, copper, or gold or an alloy can be used. Examples thereof include a support in which a metal thin film such as aluminum, chromium, silver, or gold is formed on an insulating support such as polyester resin, polycarbonate resin, polyimide resin, or glass. Moreover, the support body which formed the thin film of conductive materials, such as an indium oxide, a tin oxide, and a zinc oxide, and the thin film of the conductive ink which added silver nanowire on the insulating support body is mentioned.

  The surface of the support may be subjected to electrochemical treatment such as anodic oxidation, wet honing treatment, blast treatment, cutting treatment, etc. in order to improve electrical characteristics and suppress interference fringes.

[First intermediate layer]
A first intermediate layer is provided on the support.

  The first intermediate layer contains a phenol resin and metal oxide particles. The first intermediate layer is formed by applying a coating solution for the first intermediate layer containing a solvent, a phenol resin and metal oxide particles on a support to form a coating film, and drying and / or curing the obtained coating film Can be formed.

  The coating solution for the first intermediate layer can be prepared by dispersing a phenol resin and metal oxide particles in a solvent. Examples of the dispersion method include a method using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed disperser.

  Examples of the solvent used in the first intermediate layer coating solution include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, and propylene glycol monomethyl. Examples thereof include ethers such as ether, esters such as methyl acetate and ethyl acetate, and aromatic hydrocarbons such as toluene and xylene.

  In addition, in order to suppress the interference of light reflected on the surface of the first intermediate layer and the generation of interference fringes in the output image, the first intermediate layer has a surface for roughening the surface of the first intermediate layer. A surface roughening imparting material may be included. As the surface roughening material, resin particles having an average particle diameter of 1 μm or more and 5 μm or less are preferable. Examples of the resin particles include curable resin particles such as curable rubber, polyurethane, epoxy resin, alkyd resin, phenol resin, polyester, silicone resin, and acrylic-melamine resin. Among these, silicone resin particles that are difficult to aggregate are preferable. Further, the first intermediate layer may contain a leveling agent for enhancing the surface property of the first intermediate layer. Moreover, in order to improve the concealment property of the first intermediate layer, the first intermediate layer may contain pigment particles such as titanium oxide as one kind of metal oxide particles. The mass ratio between the metal oxide particles and the phenol resin is preferably 5/1 to 0.5 / 1, more preferably 3/1 to 1/1. The amount of the phenolic resin is preferably in the above-mentioned range because the adhesion between the first intermediate layer and the charge generation layer is excellent.

  The film thickness of the first intermediate layer is 2 to 40 μm, preferably 10 to 35 μm. The surface roughness of the first intermediate layer is more preferably from the viewpoint of improving the adhesion to the charge generation layer such that the ten-point average roughness Rzjis at a reference length of 0.8 mm is 0.5 μm or more and 2.5 μm or less. .

<Phenolic resin>
As the phenol resin, a commercially available general phenol resin can be used. Among them, the resol type phenol resin has a self-reactive functional group and can be cured as it is by heating, so that it is preferable for use as an electrophotographic photoreceptor. Examples of the resol type phenolic resin include phenolite series manufactured by DIC.

  In addition to the above-mentioned phenol resin as the binder resin, the first intermediate layer is a polymer or copolymer of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, and trifluoroethylene. It may further contain a coalescence, polyvinyl alcohol resin, polycarbonate resin, polyester resin, polysulfone resin, polyphenylene oxide resin, polyurethane resin, cellulose resin, melamine resin, silicon resin, epoxy resin and the like.

<Metal oxide particles>
Next, the metal oxide particles will be described.

  Examples of the metal oxide particles include zinc oxide, lead white, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, bismuth oxide, tin-doped indium oxide and antimony. And particles of tin oxide or zirconium oxide doped with tantalum. Among these, particles of zinc oxide, titanium oxide, and tin oxide are preferable. In preparing the coating solution for the first intermediate layer, the metal oxide particles may be surface-treated with a silane coupling agent or the like for the purpose of improving the dispersibility of the metal oxide particles. Furthermore, for the purpose of controlling the resistance of the first intermediate layer, the metal oxide particles may be doped with another element.

  The number average particle diameter of the metal oxide particles is preferably 30 to 450 nm, and more preferably 30 to 250 nm, in order to suppress the occurrence of black spots due to the formation of local conductive paths.

[Second intermediate layer]
A second intermediate layer is provided on the first intermediate layer.

  A 2nd intermediate | middle layer contains the polymer of the composition containing an electron carrying substance and a crosslinking agent.

<Electron transport material>
Examples of the electron transport material include a quinone compound, an imide compound, a benzimidazole compound, and a cyclopentadienylidene compound. The electron transport material is preferably an electron transport material having a polymerizable functional group. Examples of the polymerizable functional group include a hydroxy group, a thiol group, an amino group, a carboxyl group, or a methoxy group. Below, the compound shown by either of following formula (A1)-(A11) is shown as a specific example of an electron transport substance.

In formulas (A1) to (A11), R ^{11 to} R ¹⁶ , R ^{21 to} R ³⁰ , R ^{31 to} R ³⁸ , R ^{41 to} R ⁴⁸ , R ^{51 to} R ⁶⁰ , R ^{61 to} R ⁶⁶ , R ^{71 to} R ^{78, R 81 ~R 90, R} 91 ~R 98, R 101 ~R 110, and ^R 111 ^{to R 120} each independently represents a monovalent group represented by the following formula (a), a hydrogen atom, a cyano group , A nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. One of CH _{2 in} the main chain of the alkyl group may be replaced with O, S, NH or NR ¹²¹ (R ¹²¹ is an alkyl group). At least one of R ^{11 to} R ¹⁶ , at least one of R ^{21 to} R ³⁰ , at least one of R ^{31 to} R ³⁸ , at least one of R ^{41 to} R ⁴⁸ , at least one of R ^{51 to} R ⁶⁰ , At least one of R ^{61 to} R ⁶⁶ , at least one of R ^{71 to} R ⁷⁸ , at least one of R ^{81 to} R ⁹⁰ , at least one of R ^{91 to} R ⁹⁸ , at least one of R ^{101 to} R ¹¹⁰ , At least one of R ^{111 to} R ¹²⁰ has a monovalent group represented by the formula (A).

The substituent of the substituted alkyl group is an alkyl group, an aryl group, a halogen atom, or an alkoxycarbonyl group. The substituent of the substituted aryl group and the substituent of the substituted heterocyclic group are a halogen atom, a nitro group, a cyano group, an alkyl group, a halogen-substituted alkyl group, and an alkoxy group. Z ²¹ , Z ³¹ , Z ⁴¹ and Z ⁵¹ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. When Z ²¹ is an oxygen atom, R ²⁹ and R ³⁰ do not exist, and when Z ²¹ is a nitrogen atom, R ³⁰ does not exist. When Z ³¹ is an oxygen atom, R ³⁷ and R ³⁸ do not exist, and when Z ³¹ is a nitrogen atom, R ³⁸ does not exist. If Z ⁴¹ is an oxygen atom ^{R 47} and ^{R 48} are ^absent, when ^{Z 41} is a nitrogen atom ^{R 48} is absent. When Z ⁵¹ is an oxygen atom, R ⁵⁹ and R ⁶⁰ do not exist, and when Z ⁵¹ is a nitrogen atom, R ⁶⁰ does not exist.

式（Ａ）中、α、β、及びγの少なくとも１つは重合性官能基を有する基であり、重合性官能基は、ヒドロキシ基、チオール基、アミノ基、カルボキシル基及びメトキシ基からなる群より選択される少なくとも１種の基である。ｌ及びｍは、それぞれ独立に、０又は１であり、ｌとｍの和は、０以上２以下である。

In the formula (A), at least one of α, β, and γ is a group having a polymerizable functional group, and the polymerizable functional group is a group consisting of a hydroxy group, a thiol group, an amino group, a carboxyl group, and a methoxy group. It is at least one group selected from more. l and m are each independently 0 or 1, and the sum of l and m is 0 or more and 2 or less.

α is an alkylene group having 1-6 atoms in the main chain, an alkylene group having 1-6 atoms in the main chain substituted with an alkyl group having 1-6 carbon atoms, or a main chain substituted with a benzyl group. An alkylene group having 1 to 6 atoms, an alkylene group having 1 to 6 atoms in the main chain substituted with an alkoxycarbonyl group, or an alkylene group having 1 to 6 atoms in the main chain substituted with a phenyl group . These groups may have a polymerizable functional group. One of CH _{2 in} the main chain of the alkylene group may be replaced with O, S, NR ¹²² (wherein R ¹²² represents a hydrogen atom or an alkyl group).

  β represents a phenylene group, an alkyl group-substituted phenylene group having 1 to 6 carbon atoms, a nitro group-substituted phenylene group, a halogen group-substituted phenylene group, or an alkoxy group-substituted phenylene group. These groups may have a polymerizable functional group.

γ represents a hydrogen atom, an alkyl group having 1 to 6 atoms in the main chain, or an alkyl group having 1 to 6 atoms in the main chain substituted with an alkyl group having 1 to 6 carbon atoms. These groups may have a polymerizable functional group. One of CH _{2 in} the main chain of the alkyl group may be replaced with O, S, or NR ¹²³ (wherein R ¹²³ represents a hydrogen atom or an alkyl group).

  Specific examples of the electron transport material having a polymerizable functional group are shown below. In the table, Aa and A mean a monovalent group represented by the formula (A), and the columns Aa and A show specific examples of the monovalent group represented by the formula (A). Note that the presence of both A and Aa means that a group represented by a different formula (A) exists. In the table, when γ is “−”, it indicates a hydrogen atom, and the hydrogen atom of γ is included in the structure shown in the column of α or β. A101 to A120 are specific examples of the compound represented by the formula (A1). A201 to A206 are specific examples of the compound represented by the above formula (A2). A301 to A305 are specific examples of the compound represented by the above formula (A3). A401 to A405 are specific examples of the compound represented by the above formula (A4). A501 to A504 are specific examples of the compound represented by the above formula (A5). A601 to A605 are specific examples of the compound represented by the above formula (A6). A701 to A705 are specific examples of the compound represented by the above formula (A7). A801 to A805 are specific examples of the compound represented by the formula (A8). A901 to A907 are specific examples of the compound represented by the above formula (A9). A1001 to A1005 are specific examples of the compound represented by the formula (A10). A1101 to A1105 are specific examples of the compound represented by the formula (A11).

  Derivatives having a structure of any one of (A2) to (A6) and (A9) (derivatives of electron transport materials) are Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd., and Johnson Matthey Japan Incorporated. It can be purchased from the company. The derivative having the structure of (A1) can be synthesized by reaction of naphthalene tetracarboxylic dianhydride, which can be purchased from Tokyo Chemical Industry Co., Ltd. or Johnson Matthey Japan Incorporated, and a monoamine derivative. The derivative having the structure (A7) can be synthesized using a phenol derivative that can be purchased from Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Japan Co., Ltd. as a raw material. The derivative having the structure of (A8) can be synthesized by reaction of perylenetetracarboxylic dianhydride that can be purchased from Tokyo Chemical Industry Co., Ltd. or Sigma Aldrich Japan Co., Ltd. and a monoamine derivative. The derivative having the structure (A10) is obtained by oxidizing a phenol derivative having a hydrazone structure with an appropriate oxidizing agent such as potassium permanganate in an organic solvent using a known synthesis method described in Japanese Patent No. 3717320, for example. Can be synthesized. Derivatives having the structure of (A11) are naphthalenetetracarboxylic dianhydride, monoamine derivative and hydrazine, which can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan Co., Ltd. or Johnson Matthey Japan Incorporated. It can be synthesized by the reaction of

The compound represented by any of (A1) to (A11) has a polymerizable functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. As a method for synthesizing a compound represented by any of (A1) to (A11) by introducing a polymerizable functional group into a derivative having any one of the structures (A1) to (A11), the following method is used. Is mentioned. For example, there is a method of directly introducing a polymerizable functional group after synthesizing a derivative having any one of the structures (A1) to (A11). There is also a method of introducing a structure having a polymerizable functional group or a functional group that can be a precursor of the polymerizable functional group. As a method to be described later, based on the halide of the derivative having any one of the structures (A1) to (A11), for example, a cross-coupling reaction using a palladium catalyst and a base is used to form an aryl group having a functional group. There is a way to introduce. Further, there is a method of introducing an alkyl group having a functional group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of a derivative having any one of the structures (A1) to (A11). is there. Further, there is a method of introducing a hydroxyalkyl group or a carboxyl group by allowing an epoxy compound or CO ₂ to act after lithiation based on a halide of a derivative having any one of the structures (A1) to (A11). .

  From the viewpoint of high solvent resistance and forming a strong cross-linked structure, the electron transport material having a polymerizable functional group preferably has two or more polymerizable functional groups in the same molecule.

<Crosslinking agent>
Next, the crosslinking agent having a polymerizable functional group will be described.
As a crosslinking agent, the compound normally used as a crosslinking agent can be used. Specifically, the compounds described in Shinzo Yamashita and Tosuke Kaneko “Crosslinking Agent Handbook” published by Taiseisha (1981) and the like can be used.

The crosslinking agent used in the present invention is preferably an isocyanate compound or an amino compound. The isocyanate compound is a compound having an isocyanate group or a blocked isocyanate group. A preferred amino compound is a compound having a group represented by —CH ₂ —OH or —CH ₂ —O—R ¹ as a substituent.

  Further, the isocyanate compound preferably has 3 to 6 isocyanate groups or blocked isocyanate groups. For example, triisocyanate benzene, triisocyanate methylbenzene, triphenylmethane triisocyanate, lysine triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 2, 2,4-trimethylhexamethylene diisocyanate, methyl-2,6-diisocyanatohexanoate, norbornane diisocyanate modified isocyanurate modified, biuret modified, allophanate modified, adduct modification with trimethylolpropane and pentaerythritol Various modified bodies such as body are exemplified.

  Of these, isocyanurate-modified products and adduct-modified products are more preferable.

The blocked isocyanate group takes the form of -NHCOX (X is a protecting group). X may be any protecting group that can be introduced into an isocyanate group, but groups represented by the following (H1) to (H6) are more preferred.

  Tables 12-1 and 12-2 below show specific examples (B1) to (B21) of isocyanate compounds.

式（Ｃ１）〜（Ｃ５）中、Ｒ^１２１〜Ｒ^１２６、Ｒ^１３１〜Ｒ^１３５、Ｒ^１４１〜Ｒ^１４４、Ｒ^１５１〜Ｒ^１５４、Ｒ^１６１〜Ｒ^１６４はいずれもそれぞれ独立に、水素原子、−ＣＨ_２−ＯＨ，−ＣＨ_２−Ｏ−Ｒ^１を示し、Ｒ^１は炭素数１以上１０以下の分岐してもよいアルキル基を示す。アルキル基としてはメチル基、エチル基、ブチル基などが特に重合性の観点から好ましい。 The amino compound used in the present invention is more preferably a compound represented by any of the following formulas (C1) to (C5), and a molecular weight in the range of 200 to 1000 is a more uniform cured film formation viewpoint. To preferred.

In formulas (C1) to (C5), R ^{121 to} R ¹²⁶ , R ^{131 to} R ¹³⁵ , R ^{141 to} R ¹⁴⁴ , R ^{151 to} R ¹⁵⁴ , and R ^{161 to} R ¹⁶⁴ are each independently a hydrogen atom, − CH ₂ —OH and —CH ₂ —O—R ¹ are shown, and R ¹ represents an alkyl group having 1 to 10 carbon atoms which may be branched. As the alkyl group, a methyl group, an ethyl group, a butyl group and the like are particularly preferable from the viewpoint of polymerizability.

  Specific examples of the compounds represented by the general formulas (C1) to (C5) are shown below, but are not limited thereto. Moreover, although the following specific examples show the thing of a monomer, you may contain the oligomer which is a multimer which uses these as a structural unit. The polymerization degree of the multimer is preferably 2 or more and 100 or less. The multimers and monomers can be used in combination of two or more.

  Examples of generally commercially available compounds represented by formula (C1) include Super Melamine 90 (manufactured by NOF Corporation), Super Becamine (R) TD-139-60, L-105-60, L127. -60, L110-60, J-820-60, G-821-60 (manufactured by DIC), Uban 2020 (Mitsui Chemicals), Sumitex Resin M-3 (Sumitomo Chemical Co., Ltd.), Nicalak MW-30, MW- 390, MX-750LM (manufactured by Nippon Carbide), and the like. As a generally commercially available compound represented by the formula (C2), for example, Superbecamine (R) L-148-55, 13-535, L-145-60, TD-126 (manufactured by DIC) ), Nikaluck BL-60, BX-4000 (manufactured by Nippon Carbide), and the like. Examples of generally commercially available compounds represented by the formula (C3) include Nicalac MX-280 (manufactured by Nippon Carbide). Examples of generally commercially available compounds represented by the formula (C4) include Nicalac MX-270 (manufactured by Nippon Carbide). Examples of generally commercially available compounds represented by the formula (C5) include Nicalak MX-290 (manufactured by Nippon Carbide).

  Table 13 below shows specific examples (C1-1) to (C1-12) of the compound of the formula (C1).

  Table 14 below shows specific examples (C2-1) to (C2-18) of the compound of the formula (C2).

The composition in the second intermediate layer may further contain a thermoplastic resin having a polymerizable functional group. As the thermoplastic resin having a polymerizable functional group, a thermoplastic resin having a structural unit represented by the following formula (D) is preferable.

In formula (D), R ¹ represents a hydrogen atom or an alkyl group. Y ¹ represents a single bond, an alkylene group or a phenylene group. W ¹ represents a hydroxy group, a thiol group, an amino group, a carboxyl group, or a methoxy group.

上記式中、Ｒ^２０１〜Ｒ^２０５は、それぞれ独立に、置換もしくは無置換のアルキル基、又は置換もしくは無置換のアリール基を示す。Ｒ^２０６〜Ｒ^２１０は、それぞれ独立に、置換もしくは無置換のアルキレン基、又は置換もしくは無置換のアリーレン基を示す。Ｒ^２０１がＣ_３Ｈ_７（プロピル基）である場合は（Ｅ−１）はブチラールと示す。 Examples of the thermoplastic resin having the structural unit represented by the formula (D) include polyacetal resin, polyolefin resin, polyester resin, polyether resin, and polyamide resin. These resins preferably further have the following characteristic structure in addition to the structural unit represented by the above formula (D). Characteristic structures are shown in (E-1) to (E-5) below. (E-1) is a structural unit of a polyacetal resin. (E-2) is a structural unit of polyolefin resin. (E-3) is a structural unit of a polyester resin. (E-4) is a structural unit of a polyether resin. (E-5) is a structural unit of polyamide resin.

In the above ^formula, R 201 ^{to R 205} each independently represent a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ^{206 to} R ²¹⁰ each independently represent a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group. When R ²⁰¹ is C ₃ H ₇ (propyl group), (E-1) is represented as butyral.

  Resin having a structural unit represented by the formula (D) (hereinafter also referred to as resin D) is, for example, a polymerizable functional group (hydroxy group, thiol) that can be purchased from Sigma-Aldrich Japan Co., Ltd. or Tokyo Chemical Industry Co., Ltd. Group, amino group, carboxyl group, or methoxy group).

  The resin D can also be generally purchased. Examples of the resin that can be purchased include polyether polyol resins such as AQD-457 and AQD-473 manufactured by Nippon Polyurethane Industry Co., Ltd., Sannics GP-400 and GP-700 manufactured by Sanyo Chemical Industries, Ltd., and Hitachi Chemical. Industrial Co., Ltd., Phthakid W2343, DIC Corporation, Watersol S-118, CD-520, Beckolite M-6402-50, M-6201-40IM, Harima Kasei Co., Ltd., Hollidip WH-1188, Japan Polyester polyol resins such as Eupica ES3604 and ES6538, Polyacrylic polyol resins such as DIC Corporation, Bernock WE-300 and WE-304, and polyvinyl alcohols such as Kuraray Kuraraypoval PVA-203 Resin, BX-1, BM-1 manufactured by Sekisui Chemical Co., Ltd. Which polyvinyl acetal resin, polyamide resin such as Toraysin FS-350 manufactured by Nagase ChemteX Corporation, aqualic manufactured by Nippon Shokubai Co., Ltd., carboxyl group-containing resin such as Finelex SG2000 manufactured by Lead City, DIC ( Co., Ltd., polyamine resins such as racamide, and polythiol resins such as Toray Co., Ltd. QE-340M. Among these, polyvinyl acetal resins, polyester polyol resins and the like are more preferable from the viewpoints of polymerizability and the uniformity of the second intermediate layer.

  The weight average molecular weight (Mw) of the resin D is more preferably in the range of 5000 to 400,000.

  Examples of the quantitative method for the polymerizable functional group in the resin include the following. For example, titration of carboxyl group using potassium hydroxide, titration of amino group using sodium nitrite, titration of hydroxyl group using acetic anhydride and potassium hydroxide, 5,5′-dithiobis (2-nitrobenzoic acid) Titration of the thiol group used can be mentioned. Moreover, the calibration curve method obtained from the IR spectrum of the sample which changed the polymeric functional group introduction ratio is mentioned.

  Table 18 below shows specific examples of the resin D. In Table 18, the “characteristic site” column indicates the structural unit represented by any of (E-1) to (E-5) above.

The film thickness of the second intermediate layer is preferably from 0.3 μm to 15 μm, and more preferably from 0.5 μm to 5.0 μm.
In the present invention, in order to suppress film peeling of the photosensitive layer, it is necessary that the charge generation layer is in direct contact with the second intermediate layer without the first intermediate layer in the region in contact with the spacing member. Alternatively, the first intermediate layer and the second intermediate layer do not exist, and the charge generation layer needs to be in direct contact with the support. Alternatively, the first intermediate layer, the second intermediate layer, and the charge generation layer do not exist, and the surface layer needs to be in direct contact with the support. In general, the spacing member is installed in the end region of the electrophotographic photosensitive member, which is a non-image forming region. Therefore, in the contact region of the spacing member, the first intermediate layer coating solution or the first intermediate layer is used. The coating liquid for coating and the coating liquid for the second intermediate layer, or the first intermediate layer coating liquid, the second intermediate layer coating liquid, and the charge generation layer coating liquid are uncoated. Alternatively, there is a method in which each coating film is removed by a peeling member after applying the first intermediate layer coating solution, the second intermediate layer coating solution, and the charge generation layer coating solution.
In the present invention, in the case of dip coating, which is a general photoconductor manufacturing method, the support is used as the first intermediate layer coating solution, or the first intermediate layer coating solution and the second intermediate layer on the upper end region side of the photoconductor. The second region can be formed as non-immersed in the intermediate layer coating solution, or the first intermediate layer coating solution, the second intermediate layer coating solution, and the charge generation layer coating solution. Further, on the lower end region side of the photoreceptor, the first intermediate layer coating solution, the first intermediate layer coating solution and the second intermediate layer coating solution, or the first intermediate layer coating solution, After forming the coating film of the coating solution for 2 intermediate | middle layers and the coating liquid for charge generation layers, a 2nd area | region can be formed by removing each of these coating films with a peeling member.
Examples of the peeling member include a rubber blade, a brush, a brush, a sponge, and a fibrous cloth. In any case, the coating film can be efficiently removed by wetting the peeling member with an appropriate solvent and bringing it into contact with each other.
Other methods include a first intermediate layer coating solution, or a first intermediate layer coating solution and a second intermediate layer coating solution, or a first intermediate layer coating solution, a second intermediate layer coating solution, and a charge generation layer. There is a method of forming a coating film by performing masking on a portion of the support corresponding to the second region when immersed in the coating solution. In this method, after the first intermediate layer, the second intermediate layer, and the charge generation layer are formed, the masking is removed to form the surface layer, thereby forming the second region.

(Charge generation layer)
In the region of the photoreceptor where the spacing member does not contact, a charge generation layer is provided on the second intermediate layer. In the region of the photoreceptor where at least one spacing member abuts, a charge generation layer may be provided on the second intermediate layer or the support. The charge generation layer contains a thermoplastic resin as a binder resin. Examples thereof include polyacetal resin and benzal resin.

式（Ｆ）中、Ｒ^２は、水素原子またはアルキル基を示す。Ｙ^２は、単結合またはフェニレン基を示す。

式（Ｇ）中、Ｒ^８は置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基、または水素原子を示す。 <Polyacetal resin>
The polyacetal resin is preferably a resin having a structural unit represented by the following formula (F) and a structural unit represented by the following formula (G).

In the formula (F), R ² represents a hydrogen atom or an alkyl group. Y ² represents a single bond or a phenylene group.

In formula (G), R ⁸ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a hydrogen atom.

  These resins can also be generally purchased. Examples of the polyacetal resin that can be purchased include Slekk BK series such as BX-1, BM-1, KS-1, and KS-5 manufactured by Sekisui Chemical Co., Ltd.

  In addition to the polyacetal resin described above, the charge generation layer may be a polymer or copolymer of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, Polyvinyl alcohol resin, polycarbonate resin, polyester resin, polysulfone resin, polyphenylene oxide resin, polyurethane resin, cellulose resin, phenol resin, melamine resin, silicon resin, epoxy resin and the like may be further contained. In order to further improve the adhesion to the second intermediate layer or the support, the charge generation layer preferably contains 50% by mass or more of the polyacetal resin of the present invention among the resins in the charge generation layer.

<Charge generating material>
Charge generation materials include azo pigments, perylene pigments, anthraquinone derivatives, anthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives, isoviolanthrone derivatives, indigo derivatives, thioindigo derivatives, metal phthalocyanines, metal-free phthalocyanines, etc. Phthalocyanine pigments and bisbenzimidazole derivatives. Among these, azo pigments or phthalocyanine pigments are preferable. Among the phthalocyanine pigments, oxytitanium phthalocyanine, chlorogallium phthalocyanine, and hydroxygallium phthalocyanine are preferable.

  In the charge generation layer, the mass ratio between the charge generation material and the resin (charge generation material / resin) is preferably in the range of 10/1 to 1/10, and preferably in the range of 5/1 to 1/5. Is more preferable. The thickness of the charge generation layer is preferably 0.05 to 5 μm. Examples of the solvent used in the charge generation layer coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

(Charge transport layer)
A charge transport layer is formed on the charge generation layer. When this charge transport layer is the outermost surface, it becomes a surface layer.

  Examples of the charge transport material include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, benzidine compounds, triarylamine compounds, and triphenylamine. Alternatively, it may be a polymer having a group derived from these compounds in the main chain or side chain. Among these, a triarylamine compound, a benzidine compound, or a styryl compound is preferable.

  Examples of the binder resin used for the charge transport layer include polyester resin, polycarbonate resin, polymethacrylate resin, polyarylate resin, polysulfone resin, and polystyrene resin. Among these, polycarbonate resin and polyarylate resin are preferable. Moreover, as these molecular weight, the range of a weight average molecular weight (Mw) = 10,000-300,000 is preferable.

  In the charge transport layer, the mass ratio of the charge transport material and the binder resin (charge transport material / binder resin) is preferably 10/5 to 5/10, and more preferably 10/8 to 6/10.

  The thickness of the charge transport layer is preferably 3 μm or more and 40 μm or less. Examples of the solvent used in the charge transport layer coating liquid include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

  Further, a surface protective layer may be formed on the charge transport layer, and in this case, the surface protective layer becomes the surface layer. The surface protective layer contains conductive particles or a charge transport material and a binder resin. The surface protective layer may further contain an additive such as a lubricant. Further, the binder resin itself of the protective layer may have conductivity and charge transport property. In that case, the protective layer may not contain conductive particles other than the resin or a charge transport material. Further, the binder resin of the protective layer may be a thermoplastic resin or a curable resin that is polymerized by heat, light, radiation (electron beam, etc.), or the like. In this case, the charge transport layer and the surface protective layer can be combined to form a surface layer.

  Examples of the method for forming each layer constituting the electrophotographic photosensitive member such as the first intermediate layer, the second intermediate layer, the charge generation layer, and the surface layer include the following methods. That is, it is a method of forming by forming a coating film of a coating solution obtained by dissolving and / or dispersing materials constituting each layer in a solvent and drying the coating film. Examples of the method for applying the coating liquid include a dip coating method (dip coating method), a spray coating method, a curtain coating method, and a spin coating method. Among these, the dip coating method is preferable from the viewpoints of efficiency and productivity.

[Process cartridge and electrophotographic apparatus]
FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge provided with an electrophotographic photosensitive member.

  In FIG. 1, a cylindrical electrophotographic photosensitive member 1 is rotationally driven in a direction of an arrow about a shaft 2 at a predetermined peripheral speed. The surface (circumferential surface) of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging unit 3 (primary charging unit: charging roller or the like). Next, exposure (image exposure) 4 from exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is then developed with toner contained in the developer of the developing means 5 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred onto a transfer material (such as paper) P by a transfer bias from a transfer unit (such as a transfer roller) 6. The transfer material P is taken out from the transfer material supply means (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 1 and fed. Is done.

  The transfer material P that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member 1 and is introduced into the fixing means 8 to be image-fixed and discharged out of the apparatus as an image formed product (print, copy). The

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by receiving a developer (toner) remaining after transfer by a cleaning means (cleaning blade or the like) 7. Next, after being subjected to charge removal processing by pre-exposure light (not shown) from pre-exposure means (not shown), it is repeatedly used for image formation. As shown in FIG. 1, when the charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.

  Among the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7 described above, a plurality of components are selected and placed in a container and integrally combined as a process cartridge. May be. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 1, the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5 and the cleaning unit 7 are integrally supported to form a cartridge. The process cartridge 9 is detachably attached to the main body of the electrophotographic apparatus using guide means 10 such as a rail of the main body of the electrophotographic apparatus. The spacing member of the present invention is attached to a developer carrying member for supplying the developer to the electrophotographic photosensitive member of the developing means 5 shown in FIG. FIG. 3 shows the relationship between the developer carrying member, the electrophotographic photosensitive member, and the spacing member.

  FIG. 3 is an example of a partial layout diagram of the process cartridge in which the spacing member 11 is provided at the end of the developer carrier 5a. In FIG. 3, the interval holding member 11 has a cylindrical shape, and the interval holding member 11 is fitted into both end portions in the axial direction of the developer carrier 5a. The spacing member 11 and the electrophotographic photosensitive member 1 are in contact with each other in the contact area S outside the image forming area T. At this time, the electrophotographic photosensitive member 1 and the developer carrying member 5a are relatively rotatable, and a predetermined pressure is applied to both, so that the electrophotographic photosensitive member 1 and the developer carrying member 5a are biased in the approaching direction. ing.

  Damage to the photoconductor caused by receiving the contact force from the spacing member is large. Therefore, in order to express the effect of the present invention, at least one of the spacing members is in contact with the surface of the second region of the electrophotographic photosensitive member.

  As an example, when the development method is contact development, the developing roller as the developer carrying member needs to come into contact with the photosensitive member, and the amount of the developing roller to enter must be adjusted, and a spacing member is used. In the case of non-contact development, the distance between the sleeve, which is a developer carrying member, and the photosensitive member is very important, and a spacing member is used for these purposes.

  As the spacing member, a cylindrical member having a certain thickness is used. As the material of the spacing member, polyolefin resin such as polyethylene, polyester resin such as polyethylene terephthalate (PET), fluorine resin such as polytetrafluoroethylene (PTFE), acetal such as polyoxymethylene (POM) Resin. In addition, rubbers such as polyisoprene rubber (natural rubber), polyurethane rubber, chloroprene rubber, acrylonitrile / butadiene rubber, silicone rubber, and fluorine rubber can be used. In addition, a metal having elasticity such as aluminum, iron, copper, titanium, or an alloy containing these as a main component can be given.

In the present invention, the charging member contacts the surface of the first region of the electrophotographic photosensitive member from the viewpoint of ensuring the leakage resistance.
In the present invention, both of the spacing members may be in contact with the surface of the second region of the electrophotographic photosensitive member.
In the present invention, the electrophotographic photosensitive member further includes a first intermediate layer provided on the support, a charge generation layer provided on the first intermediate layer, and a surface layer provided on the charge generation layer. You may have the 3rd area | region which has. One of the spacing members contacts the surface of the second region of the electrophotographic photosensitive member, and the other of the spacing members contacts the surface of the third region of the electrophotographic photosensitive member.

Further, when the pressure of the spacing member that contacts the electrophotographic photosensitive member is different between one and the other, the larger pressure contacts the surface of the second region of the electrophotographic photosensitive member, and the pressure is The smaller one is preferably in contact with the surface of the third region of the electrophotographic photosensitive member.
Further, in the present invention, the film thickness of the end of the electrophotographic photosensitive member in the second direction of the electrophotographic photosensitive member in the second region of the electrophotographic photosensitive member in contact with the first spacing member is such that the film thickness at the central side of the electrophotographic photosensitive member is in contact with the charging member. It is preferable that the thickness is 7 μm or more thinner than the film thickness of the end portion on the same side as the first spacing member in the bus-line direction of the electrophotographic photosensitive member in the first region of the photographic photosensitive member. The central end of the electrophotographic photosensitive member in the bus line direction in the second region of the electrophotographic photosensitive member is the most electrophotographic among the second regions of the electrophotographic photosensitive member in contact with the first spacing member. This is an area (end) located on the center side of the photoreceptor in the direction of the generatrix. The end of the electrophotographic photosensitive member in the bus direction in the first region of the electrophotographic photosensitive member is the outermost portion of the first region of the electrophotographic photosensitive member in contact with the charging member in the bus direction of the electrophotographic photosensitive member. It is the area | region (edge part) located.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. In the examples, “part” means “part by mass”.

Example 1
An aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 260.5 mm and a diameter of 30 mm was used as a support (conductive support).

First middle layer:
214 parts of titanium oxide (TiO ₂ ) particles coated with oxygen-deficient tin oxide (SnO ₂ ) as metal oxide particles,
132 parts of phenolic resin (trade name: Priorofen J-325) as a binder resin, and
40 parts of methanol and 58 parts of 1-methoxy-2-propanol
Place in a sand mill using 450 parts of glass beads with a diameter of 0.8 mm, perform dispersion treatment under the conditions of rotation speed: 2000 rpm, dispersion treatment time: 4.5 hours, cooling water set temperature: 18 ° C. to obtain a dispersion. It was. Glass beads were removed from this dispersion with a mesh (aperture: 150 μm). Silicone oil as a leveling agent (SH28PA, manufactured by Toray Dow Corning Co., Ltd.) so that the total mass of the metal oxide particles and the binder resin in the dispersion after removing the glass beads is 0.01% by mass. Was added to the dispersion. Furthermore, the silicone resin particles (Mossive Co., Tospearl 120) are used as the dispersion so that the total mass of the metal oxide particles and the binder resin in the dispersion after removing the glass beads is 10% by mass. Added.

By stirring this dispersion, a coating solution for the first intermediate layer was prepared. The coating solution for the first intermediate layer was dip-coated on the support, and the obtained coating film was dried and thermally cured at 145 ° C. for 20 minutes to form a first intermediate layer having a thickness of 30.2 μm. .
When forming the coating film, the cylinder was immersed in the vertical direction in the coating solution, but the area from the upper end of the cylinder to 14 mm was not applied. Further, the region from the lower end of the cylinder to 2 mm was dipped and pulled up, and then wiped off with a rubber blade to expose the aluminum surface of the support.

Second middle layer:
6.3 parts of an electron transport material (A101),
11.1 parts of a crosslinking agent (B1: protecting group (H5) = 2.68: 1 (mass ratio)),
0.73 parts of resin (D25) (polyacetal resin having a partial structure in which R ²⁰¹ is CH ₃ or C ₂ H ₅ in formula (E-1)),
0.11 part of zinc hexanoate (II) as a catalyst,
A second intermediate layer coating solution was prepared by dissolving in a mixed solvent of 55 parts of tetrahydrofuran and 55 parts of 1-methoxy-2-propanol and stirring. This second intermediate layer coating solution is dip coated on the first intermediate layer, and the resulting coating film is heated for 20 minutes at 170 ° C. to polymerize the second intermediate layer with a film thickness of 0.7 μm. Formed.

  The content of the electron transport material relative to the total mass of the electron transport material, the crosslinking agent, and the resin was 52.5% by mass. When forming the coating film, the cylinder was immersed in the vertical direction in the coating solution, but the area from the upper end of the cylinder to 2 mm was not applied. Further, the region from the lower end of the cylinder to 14 mm was dipped and pulled up, then wetted in advance with a cyclohexanone solvent, and then wiped off with a rubber blade to expose the first intermediate layer surface.

Charge generation layer:
Hydroxygallium phthalocyanine crystal (charge generation material, Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 ° , With peaks at 25.1 ° and 28.3 °) 10 parts
5 parts of polyacetal resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone were placed in a sand mill using glass beads having a diameter of 1 mm and subjected to a dispersion treatment for 3 hours. Next, 250 parts of ethyl acetate was added thereto to prepare a charge generation layer coating solution. The charge generation layer coating solution is dip-coated on the second intermediate layer and the exposed first intermediate layer, and the resulting coating film is dried at 100 ° C. for 10 minutes to generate a charge having a thickness of 0.15 μm. A layer was formed.
When forming the coating film, the cylinder was immersed in the vertical direction in the coating solution, but the area from the upper end of the cylinder to 2 mm was not applied. Furthermore, the area from the lower end of the cylinder to 2 mm was dipped and pulled up, and then wiped off with a rubber blade.

Surface layer (charge transport layer):
7 parts of an amine compound represented by the following formula (4) as a charge transport material;
10 parts of a polyester resin having a structural unit represented by formula (5) and formula (6), a molar ratio of formulas (5) and (6) of 5/5 and a weight average molecular weight of 120,000,
A surface layer coating solution was prepared by dissolving in a mixed solvent of 50 parts of dimethoxymethane and 50 parts of O-xylene. The surface layer coating solution was dip-coated on the charge generation layer, and the resulting coating film was dried at 120 ° C. for 20 minutes to form a surface layer having a thickness of 22 μm.
During the formation of the coating film, the area from the upper end of the cylinder to 2 mm was not applied. Further, the area from the lower end of the cylinder to 2 mm was dipped and pulled up, and then wiped off with a rubber blade.

  As described above, an electrophotographic photosensitive member having a first region, a second region, and a third region was manufactured. A region from the 2 mm position to the 14 mm position on the upper end side of the support is a second region having a second intermediate layer, a charge generation layer, and a charge transport layer in this order on the support. The region from the upper end side 14 mm position to the lower end side 14 mm position of the support is the first region having the first intermediate layer, the second intermediate layer, the charge generation layer, and the charge transport layer in this order on the support. A region from the lower end side 2 mm position to the lower end side 14 mm position of the support is a third region having a first intermediate layer, a charge generation layer, and a charge transport layer in this order on the support.

(Evaluation of adhesion)
A laser beam printer manufactured by Hewlett-Packard Co., Ltd. (trade name: HP LaserJet Enterprise 600 M603, non-contact development method, printing speed: A4 vertical 60 sheets / min) was modified as an evaluation machine, and the adhesion was evaluated. In order to maintain (regulate) the distance between the electrophotographic photosensitive member 1 and the developer carrying member, it is a cylindrical POM (polyoxymethylene) that can rotate 4 mm around the 9 mm position from the upper and lower ends of the electrophotographic photosensitive member. The material spacing member was brought into contact. The contact force was 3000 gf on the upper end side of the electrophotographic photoreceptor 1 and 2000 gf on the lower end side. As for the contact force, the total pressure of the upper end side and the lower end side was set to 5000 gf or more. The charging roller of the charging member contacts the electrophotographic photosensitive member from the upper end side 18.1 mm to the lower end side 18.1 mm of the electrophotographic photosensitive member. The image forming area in this apparatus is an area from the upper end position of about 20 mm to the lower end position of about 20 mm of the electrophotographic photosensitive member.

  The end of the electrophotographic photosensitive member 1 in the second line region in contact with the interval holding member in the direction of the center of the electrophotographic photosensitive member 1 (11 mm position from the upper end side of the electrophotographic photosensitive member, this position is referred to as a future position A). The film thickness of the electrophotographic photosensitive member 1 was 19 μm. In the first region of the electrophotographic photosensitive member 1 in contact with the end of the charging roller, the end on the same side as the spacing member in the generatrix direction of the electrophotographic photosensitive member (18.1 mm position from the upper end side of the electrophotographic photosensitive member, The film thickness at this position (hereinafter referred to as position B) was 33 μm. A value obtained by subtracting the film thickness at the position A from the film thickness at the position B of the electrophotographic photosensitive member 1 (hereinafter, this film thickness difference is referred to as C) was 14 μm.

  Under such conditions, in an intermittent mode in which an image with a printing ratio of 0.1% is stopped on every two sheets of A4 size plain paper in an environment of a temperature of 5 ° C. and a humidity of 10% RH, 500 1,000 images were formed. When the toner runs out, it was replenished as needed. The contact state between the photosensitive layer (charge generation layer and surface layer) of the electrophotographic photosensitive member and the second intermediate layer in the region in contact with the spacing member on the upper end side was visually confirmed every 100,000 sheets. The contact state between the photosensitive layer of the electrophotographic photosensitive member and the first intermediate layer in the region in contact with the spacing member on the lower end side was visually confirmed.

The visual criteria are as follows. The results are shown in Table 20. In addition, when B, C, and D are generated, the generation location is also shown on both the upper end side, the lower end side, and the upper end side lower end side of the electrophotographic photosensitive member.
A: There is no change in the film, and it is good. B: A slight photosensitive layer is lifted on the film. C: The photosensitive layer is clearly lifted on the film, but the film is not peeled. D: The film is peeled off.

(Examples 2 to 6)
The uncoated width from the upper end side of the electrophotographic photosensitive member of each of the first intermediate layer, the second intermediate layer, the charge generation layer, and the surface layer (charge transport layer), the peeling width from the lower end side of the electrophotographic photosensitive member, and The film thickness difference C was applied, and coating was performed as shown in Table 19. Otherwise, the electrophotographic photosensitive members 2 to 6 were produced in the same manner as in Example 1. The electrophotographic photosensitive members 2 to 6 were mounted on a process cartridge set to a contact force as shown in Table 20, and the adhesion strength was evaluated in the same manner as in Example 1 using an electrophotographic apparatus.

(Example 7)
The electrophotographic photosensitive member 1 produced in Example 1 was used, and in the evaluation of adhesion, the contact force of the spacing member to the electrophotographic photosensitive member was changed so that the lower end side of the electrophotographic photosensitive member 1 was 2500 gf. Except for this, the adhesion was evaluated in the same manner as in Example 1.

(Example 8)
The electrophotographic photosensitive member 7 was produced in the same manner as in Example 1 except that the electron transport material (A117) was changed to 6.3 parts in the second intermediate layer of Example 1, and the adhesion strength was the same as in Example 1. Evaluation was made.

(Examples 9 to 10)
The uncoated width from the upper end side of the electrophotographic photosensitive member of each of the first intermediate layer, the second intermediate layer, the charge generation layer, and the surface layer (charge transport layer), the peeling width from the lower end side of the electrophotographic photosensitive member, and The film thickness difference C was applied, and coating was performed as shown in Table 19. Other than that was carried out similarly to Example 8, and produced the electrophotographic photoreceptors 8-9. The electrophotographic photoreceptors 8 to 9 were mounted on a process cartridge set to a contact force as shown in Table 20, and the adhesion strength was evaluated in the same manner as in Example 1 using an electrophotographic apparatus.

(Comparative Example 1)
A second intermediate layer coating solution was prepared and used for coating in the same manner as in Example 1 except that the resin (D25) was removed from the second intermediate layer coating solution of Example 1. Otherwise, in the same manner as in Example 1, the uncoated width from the upper end side of the electrophotographic photosensitive member of each of the first intermediate layer, the second intermediate layer, the charge generation layer, and the surface layer (charge transport layer), and the electrons A comparative electrophotographic photosensitive member 1 was prepared by applying the peeling width from the lower end side of the photographic photosensitive member and the film thickness difference C as shown in Table 19. The comparative electrophotographic photosensitive member 1 was mounted on a process cartridge set to a contact force as shown in Table 20, and the adhesion force was evaluated in the same manner as in Example 1 using an electrophotographic apparatus.

(Example 11)
Electrophotography as shown in Table 19 in the same manner as in Example 10 except that an aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 261.6 mm and a diameter of 24 mm was used as a support (conductive support). Photoconductor 10 was produced.
As described above, an electrophotographic photosensitive member having a first region and a second region was produced. A region from the 2 mm position to the 12 mm position on the upper end side of the support is a second region having a charge transport layer on the support. The region from the upper end side 12 mm position to the lower end side 12 mm position of the support is the first region having the first intermediate layer, the second intermediate layer, the charge generation layer, and the charge transport layer in this order on the support. The region from the lower end side 2 mm position to the lower end side 12 mm position of the support is the second region having the charge transport layer on the support.

Next, a laser beam printer manufactured by Hewlett-Packard Co., Ltd. (trade name: HP LaserJet Enterprise 500 Color M551, contact development method, printing speed: A4 vertical 30 sheets / min) was modified as an adhesion evaluation machine. Evaluation was performed.
A spacing member made of a POM (polyoxymethylene) material having a cylindrical shape with a width of 2 mm about 9 mm from the upper and lower ends of the electrophotographic photosensitive member 10 was brought into contact. The contact force was 2000 gf on the upper end side of the electrophotographic photoreceptor 1 and 2000 gf on the lower end side. The charging roller of the charging member contacts the electrophotographic photosensitive member from the upper end side of 14.5 mm to the lower end side of 14.5 mm. The image forming area in this apparatus is an area from the upper end position of about 20 mm to the lower end position of about 20 mm of the electrophotographic photosensitive member.
The end of the electrophotographic photosensitive member 10 in the second line region that is in contact with the spacing member in the center line direction of the electrophotographic photosensitive member 10 (10 mm from the upper end side of the electrophotographic photosensitive member, this position is referred to as a future position A ′. The film thickness of the electrophotographic photosensitive member 10 was 17 μm. In the first region of the electrophotographic photosensitive member 10 in contact with the end of the charging roller, the end on the same side as the spacing member in the generatrix direction of the electrophotographic photosensitive member (14.5 mm position from the upper end side of the electrophotographic photosensitive member, The film thickness at this position from now on as position B ′) was 30 μm. The value obtained by subtracting the film thickness at the position A ′ from the film thickness at the position B ′ of the electrophotographic photoreceptor 10 (hereinafter, this film thickness difference is C ′) was 13 μm.
Printing conditions and visual judgment were performed in the same manner as in Example 10. The results are shown in Table 20.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photosensitive member 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 8 Fixing means 9 Process cartridge 10 Guide means 11 Spacing member P Transfer material 101: Support body 102: First intermediate layer 103: Second intermediate layer 104: charge generation layer 105: surface layer

Claims (15)

A process cartridge configured to be detachable from the electrophotographic apparatus main body, wherein the process cartridge is
Cylindrical electrophotographic photoreceptor,
A developer carrying member for supplying a developer to the electrophotographic photosensitive member, a first spacing member that contacts the electrophotographic photosensitive member and holds a gap between the developer carrying member and the electrophotographic photosensitive member; A second spacing member, and
A charging member that contacts the electrophotographic photosensitive member and charges the electrophotographic photosensitive member;
The first spacing member and the second spacing member are provided at positions outside the both ends of the charging member along the generatrix direction of the electrophotographic photosensitive member,
The electrophotographic photoreceptor is
A first region having a support, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(I) a region having a support, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(Ii) a region having a support, a charge generation layer, and a surface layer in this order; and
(Iii) a support, a second region selected from a region having a surface layer provided on the support in this order;
Have
The first intermediate layer contains metal oxide particles and a phenol resin,
The second intermediate layer contains a polymer of a composition comprising an electron transport material and a crosslinking agent;
The charge generation layer contains a thermoplastic resin;
The charging member is in contact with the surface of the first region of the electrophotographic photosensitive member;
The process cartridge, wherein the first spacing member contacts the surface of the second region of the electrophotographic photosensitive member. The electrophotographic photoreceptor further has a third region having a support, a first intermediate layer, a charge generation layer, and a surface layer in this order,
The first spacing member is in contact with the surface of the second region of the electrophotographic photosensitive member;
The process cartridge according to claim 1, wherein the second spacing member is in contact with the surface of the third region of the electrophotographic photosensitive member.   The process cartridge according to claim 2, wherein a pressure applied to the first interval holding member is larger than a pressure applied to the second interval holding member at a contact portion with the electrophotographic photosensitive member.   The electrophotographic film in which the film thickness of the end portion on the central side in the generatrix direction of the electrophotographic photosensitive member in the second region of the electrophotographic photosensitive member that is in contact with the first spacing member is in contact with the charging member 4. The process cartridge according to claim 2, wherein the process cartridge is thinner by 7 μm or more than the film thickness of the end portion on the same side as the first spacing member in the generatrix direction of the electrophotographic photoreceptor in the first region of the photoreceptor.   2. The process cartridge according to claim 1, wherein both the first spacing member and the second spacing member are in contact with the surface of the second region of the electrophotographic photosensitive member. The process cartridge according to claim 1, wherein the electron transport material of the second intermediate layer is a compound represented by any one of the following formulas (A1) to (A11).

In formulas (A1) to (A11), R ^{11 to} R ¹⁶ , R ^{21 to} R ³⁰ , R ^{31 to} R ³⁸ , R ^{41 to} R ⁴⁸ , R ^{51 to} R ⁶⁰ , R ^{61 to} R ⁶⁶ , R ^{71 to} R ^{78, R 81 ~R 90, R} 91 ~R 98, R 101 ~R 110, R 111 ~R 120 are each independently a monovalent group represented by the following formula (a), a hydrogen atom, a cyano group, A nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic ring is shown. One of CH _{2 in} the main chain of the alkyl group may be replaced with O, S, NH or NR ¹²¹ (R ¹²¹ is an alkyl group). At least one of R ^{11 to} R ¹⁶ , at least one of R ^{21 to} R ³⁰ , at least one of R ^{31 to} R ³⁸ , at least one of R ^{41 to} R ⁴⁸ , at least one of R ^{51 to} R ⁶⁰ , At least one of R ^{61 to} R ⁶⁶ , at least one of R ^{71 to} R ⁷⁸ , at least one of R ^{81 to} R ⁹⁰ , at least one of R ^{91 to} R ⁹⁸ , at least one of R ^{101 to} R ¹¹⁰ , At least one of R ^{111 to} R ¹²⁰ has a monovalent group represented by the formula (A).
The substituent of the substituted alkyl group is an alkyl group, an aryl group, a halogen atom, or an alkoxycarbonyl group. The substituent of the substituted aryl group and the substituent of the substituted heterocyclic group are a halogen atom, a nitro group, a cyano group, an alkyl group, a halogen-substituted alkyl group, and an alkoxy group. Z ²¹ , Z ³¹ , Z ⁴¹ and Z ⁵¹ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. When Z ²¹ is an oxygen atom, R ²⁹ and R ³⁰ do not exist, and when Z ²¹ is a nitrogen atom, R ³⁰ does not exist. When Z ³¹ is an oxygen atom, R ³⁷ and R ³⁸ do not exist, and when Z ³¹ is a nitrogen atom, R ³⁸ does not exist. If Z ⁴¹ is an oxygen atom ^{R 47} and ^{R 48} are ^absent, when ^{Z 41} is a nitrogen atom ^{R 48} is absent. When Z ⁵¹ is an oxygen atom, R ⁵⁹ and R ⁶⁰ do not exist, and when Z ⁵¹ is a nitrogen atom, R ⁶⁰ does not exist.

In the formula (A), at least one of α, β, and γ is a group having a polymerizable functional group, and the polymerizable functional group is a group consisting of a hydroxy group, a thiol group, an amino group, a carboxyl group, and a methoxy group. It is at least one group selected from more. l and m are each independently 0 or 1, and the sum of l and m is 0 or more and 2 or less.
α is an alkylene group having 1-6 atoms in the main chain, an alkylene group having 1-6 atoms in the main chain substituted with an alkyl group having 1-6 carbon atoms, or a main chain substituted with a benzyl group. An alkylene group having 1 to 6 atoms, an alkylene group having 1 to 6 atoms in the main chain substituted with an alkoxycarbonyl group, or an alkylene group having 1 to 6 atoms in the main chain substituted with a phenyl group . These groups may have a polymerizable functional group. One of CH _{2 in} the main chain of the alkylene group may be replaced with O, S, NR ¹²² (wherein R ¹²² represents a hydrogen atom or an alkyl group).
β represents a phenylene group, an alkyl group-substituted phenylene group having 1 to 6 carbon atoms, a nitro group-substituted phenylene group, a halogen group-substituted phenylene group, or an alkoxy group-substituted phenylene group. These groups may have a polymerizable functional group.
γ represents a hydrogen atom, an alkyl group having 1 to 6 atoms in the main chain, or an alkyl group having 1 to 6 atoms in the main chain substituted with an alkyl group having 1 to 6 carbon atoms. These groups may have a polymerizable functional group. One of CH _{2 in} the main chain of the alkyl group may be replaced with O, S, or NR ¹²³ (wherein R ¹²³ represents a hydrogen atom or an alkyl group).   The process cartridge according to claim 1, wherein the thermoplastic resin of the charge generation layer is a polyacetal resin or a benzal resin. A cylindrical electrophotographic photosensitive member, a developer carrying member for supplying a developer to the electrophotographic photosensitive member, and the electrophotographic photosensitive member abutting the gap between the developer carrying member and the electrophotographic photosensitive member A first spacing member and a second spacing member to be held, and
A charging member that contacts the electrophotographic photosensitive member and charges the electrophotographic photosensitive member;
An electrophotographic apparatus comprising:
The first spacing member and the second spacing member are provided at positions outside the both ends of the charging member along the generatrix direction of the electrophotographic photosensitive member,
The electrophotographic photoreceptor is
A first region having a support, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(I) a region having a support, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(Ii) a region having a support, a charge generation layer, and a surface layer in this order; and
(Iii) a support, a second region selected from a region having a surface layer provided on the support in this order;
Have
The first intermediate layer contains metal oxide particles and a phenol resin,
The second intermediate layer contains a polymer of a composition comprising an electron transport material and a crosslinking agent;
The charge generation layer contains a thermoplastic resin;
The charging member is in contact with the surface of the first region of the electrophotographic photosensitive member;
The electrophotographic apparatus, wherein the first spacing member is in contact with the surface of the second region of the electrophotographic photosensitive member. The electrophotographic photoreceptor further has a third region having a support, a first intermediate layer, a charge generation layer, and a surface layer in this order,
The first spacing member is in contact with the surface of the second region of the electrophotographic photosensitive member;
The electrophotographic apparatus according to claim 8, wherein the second spacing member is in contact with the surface of the third region of the electrophotographic photosensitive member.   The electrophotographic apparatus according to claim 9, wherein a pressure applied to the first spacing member is higher than a pressure applied to the second spacing member at a contact portion with the electrophotographic photosensitive member.   The electrophotographic film in which the film thickness of the end portion on the central side in the generatrix direction of the electrophotographic photosensitive member in the second region of the electrophotographic photosensitive member that is in contact with the first spacing member is in contact with the charging member 11. The electrophotographic apparatus according to claim 9, wherein the electrophotographic apparatus is thinner by 7 μm or more than a film thickness of an end portion on the same side as the first spacing member in the generatrix direction of the electrophotographic photoreceptor in the first region of the photoreceptor.   The electrophotographic apparatus according to claim 8, wherein both the first spacing member and the second spacing member are in contact with the surface of the second region of the electrophotographic photosensitive member. The electrophotographic apparatus according to any one of claims 8 to 12, wherein the electron transport material of the second intermediate layer is a compound represented by any one of the following formulas (A1) to (A11).

In formulas (A1) to (A11), R ^{11 to} R ¹⁶ , R ^{21 to} R ³⁰ , R ^{31 to} R ³⁸ , R ^{41 to} R ⁴⁸ , R ^{51 to} R ⁶⁰ , R ^{61 to} R ⁶⁶ , R ^{71 to} R ^{78, R 81 ~R 90, R} 91 ~R 98, R 101 ~R 110, R 111 ~R 120 are each independently a monovalent group represented by the following formula (a), a hydrogen atom, a cyano group, A nitro group, a halogen atom, an alkoxycarbonyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic ring is shown. One of CH _{2 in} the main chain of the alkyl group may be replaced with O, S, NH or NR ¹²¹ (R ¹²¹ is an alkyl group). At least one of R ^{11 to} R ¹⁶ , at least one of R ^{21 to} R ³⁰ , at least one of R ^{31 to} R ³⁸ , at least one of R ^{41 to} R ⁴⁸ , at least one of R ^{51 to} R ⁶⁰ , At least one of R ^{61 to} R ⁶⁶ , at least one of R ^{71 to} R ⁷⁸ , at least one of R ^{81 to} R ⁹⁰ , at least one of R ^{91 to} R ⁹⁸ , at least one of R ^{101 to} R ¹¹⁰ , At least one of R ^{111 to} R ¹²⁰ has a monovalent group represented by the formula (A).
The substituent of the substituted alkyl group is an alkyl group, an aryl group, a halogen atom, or an alkoxycarbonyl group. The substituent of the substituted aryl group and the substituent of the substituted heterocyclic group are a halogen atom, a nitro group, a cyano group, an alkyl group, a halogen-substituted alkyl group, and an alkoxy group. Z ²¹ , Z ³¹ , Z ⁴¹ and Z ⁵¹ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. When Z ²¹ is an oxygen atom, R ²⁹ and R ³⁰ do not exist, and when Z ²¹ is a nitrogen atom, R ³⁰ does not exist. When Z ³¹ is an oxygen atom, R ³⁷ and R ³⁸ do not exist, and when Z ³¹ is a nitrogen atom, R ³⁸ does not exist. If Z ⁴¹ is an oxygen atom ^{R 47} and ^{R 48} are ^absent, when ^{Z 41} is a nitrogen atom ^{R 48} is absent. When Z ⁵¹ is an oxygen atom, R ⁵⁹ and R ⁶⁰ do not exist, and when Z ⁵¹ is a nitrogen atom, R ⁶⁰ does not exist.

In the formula (A), at least one of α, β, and γ is a group having a polymerizable functional group, and the polymerizable functional group is a group consisting of a hydroxy group, a thiol group, an amino group, a carboxyl group, and a methoxy group. It is at least one group selected from more. l and m are each independently 0 or 1, and the sum of l and m is 0 or more and 2 or less.
α is an alkylene group having 1-6 atoms in the main chain, an alkylene group having 1-6 atoms in the main chain substituted with an alkyl group having 1-6 carbon atoms, or a main chain substituted with a benzyl group. An alkylene group having 1 to 6 atoms, an alkylene group having 1 to 6 atoms in the main chain substituted with an alkoxycarbonyl group, or an alkylene group having 1 to 6 atoms in the main chain substituted with a phenyl group . These groups may have a polymerizable functional group. One of CH _{2 in} the main chain of the alkylene group may be replaced with O, S, NR ¹²² (wherein R ¹²² represents a hydrogen atom or an alkyl group).
β represents a phenylene group, an alkyl group-substituted phenylene group having 1 to 6 carbon atoms, a nitro group-substituted phenylene group, a halogen group-substituted phenylene group, or an alkoxy group-substituted phenylene group. These groups may have a polymerizable functional group.
γ represents a hydrogen atom, an alkyl group having 1 to 6 atoms in the main chain, or an alkyl group having 1 to 6 atoms in the main chain substituted with an alkyl group having 1 to 6 carbon atoms. These groups may have a polymerizable functional group. One of CH _{2 in} the main chain of the alkyl group may be replaced with O, S, or NR ¹²³ (wherein R ¹²³ represents a hydrogen atom or an alkyl group).   The electrophotographic apparatus according to claim 8, wherein the thermoplastic resin of the charge generation layer is a polyacetal resin or a benzal resin. The electrophotographic photoreceptor is
A first region having a support, a first intermediate layer, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(I) a region having a support, a second intermediate layer, a charge generation layer, and a surface layer in this order;
(Ii) a region having a support, a charge generation layer, and a surface layer in this order; and
(Iii) a support, a second region selected from a region having a surface layer provided on the support in this order;
Have
The first intermediate layer contains metal oxide particles and a phenol resin,
The second intermediate layer contains a polymer of a composition comprising an electron transport material and a crosslinking agent;
An electrophotographic photoreceptor, wherein the charge generation layer contains a thermoplastic resin.

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