JP2015210446A - Electrophotographic photoreceptor, process cartridge, and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having reduced potential variations, and a process cartridge and an electrophotographic device having the electrophotographic photoreceptor.SOLUTION: An undercoat layer of an electrophotographic photoreceptor comprises a polymer of a composition comprising a compound represented by formula (1), and a charge transport layer of the electrophotographic photoreceptor comprises a resin comprising silicon atoms.

Description

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

  Currently, as an electrophotographic photosensitive member mounted on a process cartridge or an electrophotographic apparatus, there is an electrophotographic photosensitive member containing an organic photoconductive substance (charge generating substance).

  An electrophotographic photoreceptor generally has a support and a photosensitive layer formed on the support. An undercoat layer is often provided between the support and the photosensitive layer for the purpose of suppressing charge injection from the support to the photosensitive layer side and suppressing the occurrence of image defects such as black spots. .

  In recent years, materials having higher sensitivity have been used as charge generating materials for electrophotographic photoreceptors. As the charge generating material becomes highly sensitive, the amount of generated charge increases, so that the charge tends to stay in the photosensitive layer and the potential fluctuation tends to increase. Specifically, in the output image, the color of the initial image and the image after output of 1000 sheets are different.

  As a technique for suppressing (reducing) such potential fluctuations, Patent Document 1 discloses a technique in which an undercoat layer contains an electron transport material such as an imide compound.

JP 2001-83726 A

  In recent years, the demand for the quality of electrophotographic images has been increasing, and the permissible range for the above-described potential fluctuation has become much stricter.

  As a result of the study by the present inventors, in the technique disclosed in Patent Document 1, suppression of potential fluctuation may not be sufficiently improved, and further improvement is necessary.

  An object of the present invention is to provide an electrophotographic photosensitive member in which potential fluctuation is suppressed, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

A support, an undercoat layer provided on the support, a charge generation layer provided on the undercoat layer, and a charge transport layer provided on the charge generation layer, and the charge transport An electrophotographic photoreceptor in which the layer is a surface layer,
The undercoat layer contains a polymer of a composition containing a compound represented by the following formula (1),
The electrophotographic photoreceptor, wherein the charge transport layer contains a resin containing a silicon atom.

(In formula (1), R ^{101 to} R ¹⁰⁶ 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, substituted or unsubstituted A substituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, and one of the carbon atoms in the main chain of the alkyl group is O, S, NR ²⁰¹ (R ²⁰¹ is It represents a hydrogen atom or an alkyl group, and at least one of R ^{101 to} R ¹⁰⁶ is a monovalent group represented by the following formula (A).

  The substituent of the substituted alkyl group is a group selected from the group consisting of an alkyl group, an aryl group, an alkoxycarbonyl group, and a halogen atom.

  The substituent of the substituted aryl group is a group selected from the group consisting of a halogen atom, a nitro group, a cyano group, an alkyl group, and a halogenated alkyl group. )

  In formula (A), at least one of α, β, and γ is a group having a substituent, and the substituent is at least selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group. One kind of group. 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 at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkylene group may be replaced with O, S, or NR ³⁰¹ (R ³⁰¹ is a hydrogen atom or an alkyl group).

  β represents a phenylene group, an alkyl-substituted phenylene group having 1 to 6 carbon atoms, a nitro group-substituted phenylene group, a halogenated phenylene group, or an alkoxy group-substituted phenylene group. These groups may have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent.

γ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, 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 at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkyl group may be replaced with NR ⁴⁰¹ (R ⁴⁰¹ represents an alkyl group). )
Further, the present invention integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, and is detachable from the main body of the electrophotographic apparatus. It relates to a certain process cartridge.

  The present invention also relates to an electrophotographic apparatus having the electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member in which potential fluctuation is suppressed, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

1 is a diagram illustrating a schematic configuration of an electrophotographic apparatus having a process cartridge including the electrophotographic photosensitive member of the present invention. It is a figure explaining the photoconductor testing machine which measures the surface potential of an electrophotographic photoconductor.

  The present invention includes a support, an undercoat layer provided on the support, a charge generation layer provided on the undercoat layer, and a charge transport layer provided on the charge generation layer, and the charge transport The present invention relates to an electrophotographic photosensitive member whose layer is a surface layer. The undercoat layer contains a polymer of a composition containing a compound represented by the following formula (1), and the charge transport layer contains a resin containing a silicon atom.

In formula (1), R ^{101 to} R ¹⁰⁶ 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, substituted or unsubstituted An alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. One of the carbon atoms in the main chain of the alkyl group may be replaced with O, S, NR ²⁰¹ (R ²⁰¹ represents a hydrogen atom or an alkyl group). At least one of R ^{101 to} R ¹⁰⁶ is a monovalent group represented by the following formula (A).

  The substituent of the substituted alkyl group is a group selected from the group consisting of an alkyl group, an aryl group, an alkoxycarbonyl group, and a halogen atom.

  The substituent of the substituted aryl group is a group selected from the group consisting of a halogen atom, a nitro group, a cyano group, an alkyl group, and a halogenated alkyl group.

  In formula (A), at least one of α, β, and γ is a group having a substituent, and the substituent is at least selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group. One kind of group. 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 at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkylene group, O or S or NR ^{301 (R 301} is a hydrogen atom or an alkyl group.) It may be replaced by.

  β represents a phenylene group, an alkyl-substituted phenylene group having 1 to 6 carbon atoms, a nitro group-substituted phenylene group, a halogenated phenylene group, or an alkoxy group-substituted phenylene group. These groups may have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent.

γ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, 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 at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkyl group may be replaced with NR ⁴⁰¹ (R ⁴⁰¹ represents an alkyl group). )
In the compound represented by the formula (1), at least one of R ¹⁰⁵ and ¹⁰⁶ is a monovalent group represented by the above formula (A), which has a great effect of suppressing potential fluctuation.

  In formula (A), at least one of α, β, and γ is a group having the substituent, and the fact that the substituent is a hydroxy group has a great effect of suppressing potential fluctuation. Moreover, you may mix 2 or more types of compounds shown by Formula (1).

[Support]
As the support, those having conductivity (conductive support) are preferable, and for example, a support made of a metal such as aluminum, nickel, copper, gold, iron, or an alloy can be used. A support in which a thin film of metal such as aluminum, silver, or gold is formed on an insulating support such as polyester resin, polycarbonate resin, polyimide resin, or glass, or a thin film of conductive material such as indium oxide or tin oxide is formed. A support 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.

  A conductive layer may be provided between the support and the undercoat layer described below. The conductive layer can be obtained by forming a coating film of a coating liquid for conductive layer in which conductive particles are dispersed in a resin on a support and drying it. Examples of the conductive particles include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, and metal oxide powder such as conductive tin oxide and ITO. Can be mentioned.

  Examples of the resin include polyester resin, polycarbonate resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

  Examples of the solvent for the conductive layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents. The thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or less, more preferably 1 μm or more and 35 μm or less, and even more preferably 5 μm or more and 30 μm or less.

  As a general electrophotographic photosensitive member, a cylindrical electrophotographic photosensitive member in which a photosensitive layer (charge generation layer, charge transport layer) is formed on a cylindrical support is widely used. It is also possible to have a shape of

[Undercoat layer]
An undercoat layer is provided between the support or the conductive layer and the charge generation layer.

  This invention contains the polymer of the composition in which an undercoat layer contains the compound shown by the said Formula (1).

  Among these exemplary compounds, compounds represented by the following formulas (11) to (15) are preferable from the viewpoint of suppressing potential fluctuation.

  Derivatives having a structure represented by the formula (1) (derivatives of electron transport materials) are disclosed in, for example, US Pat. No. 4,442,193, US Pat. No. 4,992,349, US Pat. No. 5,468,583, Chemistry of materials, Vol. 19, no. It is possible to synthesize using a known synthesis method described in 11, 2703-2705 (2007). Moreover, it is compoundable by reaction with the naphthalene tetracarboxylic dianhydride and monoamine derivative which can be purchased from Tokyo Chemical Industry Co., Ltd., Sigma Aldrich Japan Co., Ltd., and Johnson Matthey Japan Incorporated.

The compound represented by the formula (1) has a polymerizable functional group (hydroxy group, thiol group, amino group, and carboxyl group). As a method of introducing these substituents into the derivative having the structure of the formula (1), a method of directly introducing a polymerizable functional group into the derivative having the structure of the formula (1), the polymerizable functional group, or the polymerizable There is a method of introducing a structure having a functional group that can be a precursor of a functional group. As a method to be described later, for example, there is a method of introducing a functional group-containing aryl group using a cross-coupling reaction using a palladium catalyst and a base based on a halide of a naphthylimide derivative. For example, there is a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base based on a halide of a naphthylimide derivative. Further, there is a method of introducing a hydroxyalkyl group or a carboxyl group by reacting an epoxy compound or CO2 after lithiation based on a halide of a naphthylimide derivative. As a raw material for synthesizing a naphthylimide derivative, there is a method using the naphthalenetetracarboxylic dianhydride derivative or monoamine derivative having the polymerizable functional group or a functional group that can be a precursor of the polymerizable functional group.

  As a raw material for synthesizing a naphthylimide derivative, there is a method using the naphthalenetetracarboxylic dianhydride derivative or monoamine derivative having the polymerizable functional group or a functional group that can be a precursor of the polymerizable functional group.

  Although the undercoat layer contains a polymer of a composition containing the compound represented by formula (1), it is preferable that the composition further contains a crosslinking agent and a resin.

  The crosslinking agent will be described. As the crosslinking agent, an electron transport material having a polymerizable functional group and a compound that polymerizes or crosslinks with a thermoplastic resin having a polymerizable functional group can be used. Specifically, compounds described in Shinzo Yamashita and Tosuke Kaneko “Crosslinking Agent Handbook” published by Taiseisha (1981) and the like can be used.

  Examples of the functional group in the crosslinking agent include -NCO group (hereinafter also referred to as isocyanate group), -NOR group, -SiOR group, acrylic group and the like. Among these, an isocyanate group is preferable from the viewpoint of suppressing potential fluctuation.

Furthermore, an isocyanate compound having 2 to 6 isocyanate groups (—NCO groups) or blocked isocyanate groups (—NHCOX ¹ group, X ¹ is a protecting group) is preferable. X ¹ may be any protecting group that can be introduced into an isocyanate group, but is more preferably a group represented by any of the following formulas (X1) to (X7).

  Specifically, triisocyanate benzene, triphenylmethane triisocyanate, lysine triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 2,2,4-trimethyl Examples include various modified products such as isocyanurate modified products of biisocyanates such as hexamethylene diisocyanate, methyl-2,6-diisocyanate hexanoate, norbornane diisocyanate, biuret modified products, allophanate modified products, and adducts with trimethylolpropane.

  The isocyanate compound of the present invention preferably has a cyclic structure. More preferred is an isocyanurate structure, which is the structure shown below.

  As commercially available isocyanate compounds, for example, Sumika Bayer Urethane Co., Ltd., BL3175, BL3475, BL3575, Asahi Kasei Chemicals Corporation, TPA-B80E, TPA-B80X, SBN-70D, SBN-70M, etc. should be used. Can do.

  As the resin, a thermoplastic resin having a polymerizable functional group is preferable. Examples of the thermoplastic resin include thermoplastic resins having a structural unit represented by the following formula (B).

In the formula (B), R ¹¹ represents a hydrogen atom or an alkyl group. Y represents a single bond or a phenylene group. W ¹ represents a hydroxy group, a thiol group, an amino group, or a carboxyl group.

  Examples of the thermoplastic resin having the structural unit represented by the formula (B) include an acetal resin, a polyolefin resin, a polyester resin, a polyether resin, and a polyamide resin. The structural unit represented by the above formula (B) may be included in the following characteristic structure, or may be included other than the characteristic structure. Characteristic structures are shown in the following (B-1) to (B-5). (B-1) is a structural unit of an acetal resin. (B-2) is a structural unit of a polyolefin resin. (B-3) is a structural unit of a polyester resin. (E-4) is a structural unit of a polyether resin. (B-5) is a structural unit of polyamide resin.

In the above formula, R ^{501 to} R ⁵¹⁰ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.

  Examples of the resin that can be purchased as the thermoplastic resin having the structural unit represented by the above formula (B) include the following. 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 Industry Co., Ltd., Phthalkid W2343 manufactured by Hitachi Chemical Co., Ltd., DIC Polyester polyol resins such as Watersol S-118 and CD-520 manufactured by Harima Chemical Co., Ltd., and Haripip WH-1188 manufactured by Harima Kasei Co., Ltd. Polyacrylic polyols such as Burnock WE-300 and WE-304 manufactured by DIC Corporation Resins, polyvinyl alcohol resins such as Kuraray Kuraraypoval PVA-203, Sekisui Chemical Co., Ltd. KW-1 and KW-3, BX-1, BM-1, KS-1, KS -3, KS-5Z and other polyvinyl acetal resins, Toraysin F manufactured by Nagase ChemteX Corporation -350 and other polyamide compound resins, Nippon Shokubai Co., Ltd. Aquaric, Lead City Co., Ltd. Finelex SG2000 and other carboxyl group-containing resins, DIC Co., Ltd. racamide and other polyamines, Toray Industries, Inc. QE Polythiols such as -340M.

  The undercoat layer of the present invention may contain a catalyst for the purpose of promoting polymerization. Examples of the catalyst include dibutyltin dilaurate, amine catalyst, and metal soap.

  Examples of the solvent used in the coating solution for the undercoat layer include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

  As a form of polymerization, a crosslinking agent, a compound represented by the formula (1), and a resin having a structural unit represented by the formula (B) react to form a polymer (cured product).

  The undercoat layer of the present invention forms an undercoat layer by forming a coating film of a coating solution for an undercoat layer containing the compound represented by the formula (1) and heating and drying the coating film. Although these compounds are polymerized (cured) by a chemical reaction after the coating film is formed, the chemical reaction is accelerated and the polymerization is accelerated by heating at that time.

  The content of the polymer is preferably 50% by mass or more and 100% by mass or less, and preferably 80% by mass or more and 100% by mass or less with respect to the total mass of the undercoat layer, from the viewpoint of suppressing potential fluctuation. Is more preferable.

  In addition to the polymer, the undercoat layer may contain organic fine particles, inorganic fine particles, a leveling agent, and the like in order to improve the film formability and electrical characteristics of the undercoat layer. However, their content in the undercoat layer is preferably less than 50% by mass and more preferably less than 20% by mass with respect to the total mass of the undercoat layer.

  In addition, another layer such as a second undercoat layer not containing the polymer according to the present invention may be provided between the support and the undercoat layer or between the undercoat layer and the photosensitive layer. .

  The compound according to the present invention was confirmed by the following method.

-Mass spectrometry The molecular weight was measured using a mass spectrometer (MALDI-TOF MS: ultraflex manufactured by Bruker Daltonics Co., Ltd.) under the conditions of acceleration voltage: 20 kV, mode: Reflector, molecular weight standard product: fullerene C60. It confirmed with the obtained peak top value.

NMR analysis 1H-NMR, 13C-NMR analysis (FT-NMR: JNM-manufactured by JEOL Ltd.) in 1,1,2,2-tetrachloroethane (d2) or dimethyl sulfoxide (d6) at 120 ° C. The structure was confirmed by EX400 type).

-GPC analysis It measured with the gel permeation chromatography "HLC-8120" by Tosoh Corporation, and computed in polystyrene conversion.

  In addition, an undercoat layer obtained by forming a coating film of an undercoat layer coating solution containing an isocyanate compound, a resin, and an electron transport material, and heating and drying the coating film is immersed in cyclohexanone, before and after the immersion. The weight of the undercoat layer was confirmed. It was confirmed that the components of the undercoat layer were not dissolved by immersion, and were cured (polymerized).

-Surface roughness Rzjis (X) was confirmed using the contact-type surface roughness meter (Brand name: Surfcorder SE3500, Kosaka Laboratory (made)) as a measuring device. Measurement length: 2.5 mm, measurement speed: 0.1 mm / second, the measurement location is the average of 12 points in the longitudinal direction, 3 points each of 30 mm, 185 mm, and 340 mm from the upper end of the coating, 4 points in the circumferential direction The value was taken as data.

(Charge generation layer)
A charge generation layer is provided on the undercoat layer.
Examples of charge generating 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.

  Examples of the binder resin used for the charge generation layer include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, and polyvinyl alcohol. Examples thereof include resins, polyvinyl acetal resins, polycarbonate resins, polyester resins, polysulfone resins, polyphenylene oxide resins, polyurethane resins, cellulose resins, phenol resins, melamine resins, silicon resins, and epoxy resins. Among these, polyester resin, polycarbonate resin, and polyvinyl acetal resin are preferable, and among these, polyvinyl acetal resin is more preferable.

  In the charge generation layer, the mass ratio of the charge generation material to the binder resin (charge generation material / binder resin) is preferably in the range of 10/1 to 1/10, and is preferably 5/1 to 1/5. A range is more preferable. The thickness of the charge generation layer is preferably 0.05 μm or more and 5 μm or less. 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 provided on the charge generation layer. The charge transport layer is the surface layer. The charge transport layer contains a resin containing silicon atoms. This resin is preferably a resin having a siloxane structure. The siloxane structure is a site including silicon atoms at both ends constituting the siloxane structure and groups bonded thereto, and oxygen atoms, silicon atoms and groups bonded thereto sandwiched between the silicon atoms at both ends.

  The resin having a siloxane structure is preferably a polycarbonate resin having a siloxane structure or a polyester resin having a siloxane structure.

  Moreover, it is preferable that content of the siloxane structure in resin containing a silicon atom (siloxane structure) is 10 mass% or more and 40 mass% or less.

  Examples of the charge transport material (hole transport material) include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, benzidine compounds, triarylamine compounds, and triphenylamine. Also included are polymers having groups derived from these compounds in the main chain or side chain.

  In the charge transport layer (hole transport layer), a resin other than the resin containing silicon atoms may be used in combination. Examples of resins other than resins containing silicon atoms include polyester resins, polycarbonate resins, polymethacrylate resins, polyarylate resins, polysulfone resins, and polystyrene resins. Among these, polycarbonate resin and polyarylate resin are preferable. Moreover, it is preferable that these weight average molecular weights (Mw) are the range of 10,000-300,000.

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

  As a method for forming each layer constituting the electrophotographic photosensitive member such as an undercoat layer, a charge generation layer, a charge transport layer, and an outermost surface layer, the material constituting each layer was obtained by dissolving and / or dispersing in a solvent. A coating solution is applied to form a coating film. Then, the method of forming by drying and / or hardening the obtained coating film is preferable. 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 the electrophotographic photosensitive member of the present invention.

  In FIG. 1, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which 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, it receives exposure light (image exposure light) 4 from exposure means (not shown) such as slit exposure or laser beam scanning exposure. 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 introduced into the fixing means 8 to receive the image fixing, and is printed out as an image formed product (print, copy). Is done.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by receiving a transfer residual developer (transfer residual toner) 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.

  Of the above-described components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7, a plurality of components may be housed in a container and integrally combined as a process cartridge. Good. 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.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “part” means “part by mass”. First, a synthesis example of a compound (electron transport material) represented by the formula (1) is shown.

(Synthesis Example 1)
In a 300 ml three-necked flask under a nitrogen stream at room temperature, 26.8 parts (100 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 150 parts of dimethylacetamide were placed. To this, a mixture of 6.9 parts (50 mmol) of 2- (4-aminophenyl) ethanol, 5.9 parts (50 mmol) of L-leucinol and 50 parts of dimethylacetamide was added dropwise with stirring. After completion of dropping, the mixture was heated to reflux for 6 hours. After completion of the reaction, the container was cooled and concentrated under reduced pressure. Ethyl acetate was added to the residue, followed by filtration, and the filtrate was concentrated using silica gel column chromatography (developing solvent: ethyl acetate / toluene). Furthermore, the concentrate was recrystallized with a mixed solution of ethyl acetate / hexane to obtain 15.0 parts of a compound represented by the formula (11).

(Synthesis Example 2)
Under a nitrogen atmosphere, 5.4 parts of naphthalenetetracarboxylic dianhydride, 4 parts of 2,6-diisopropylaniline and 3 parts of 2-amino-1,3-propanediol are added to 200 parts of dimethylacetamide. Stir for hours to prepare a solution.

  After preparing the solution, the mixture was refluxed for 10 hours and separated by silica gel column chromatography (developing solvent: ethyl acetate / toluene), and then the fraction containing the desired product was concentrated. The concentrate was recrystallized with an ethyl acetate / toluene mixed solution to obtain 1.5 parts of a compound represented by the formula (12).

(Synthesis Example 3)
To 200 parts of dimethylacetamide, 5.4 parts of naphthalenetetracarboxylic dianhydride and 5.2 parts of leucinol were added under a nitrogen atmosphere, stirred at room temperature for 1 hour, and then refluxed for 7 hours. After removing dimethylacetamide by distillation under reduced pressure, recrystallization was performed with ethyl acetate to obtain 5.0 parts of a compound represented by the formula (13).

(Synthesis Example 4)
In a nitrogen atmosphere, 5.4 parts of naphthalenetetracarboxylic dianhydride, 4 parts of 4-heptylamine and 3 parts of 2-amino-1,3-propanediol are added to 200 parts of dimethylacetamide and stirred at room temperature for 1 hour. To prepare a solution. After preparing the solution, the mixture was heated to reflux for 8 hours, separated by silica gel column chromatography (developing solvent: ethyl acetate / toluene), and the fraction containing the desired product was concentrated. The concentrate was recrystallized with an ethyl acetate / toluene mixed solution to obtain 2.0 parts of a compound represented by the formula (14).

(Synthesis Example 5)
Under a nitrogen atmosphere, 5.4 parts of naphthalenetetracarboxylic dianhydride, 2.6 parts of leucinol and 2.7 parts of 2- (2-aminoethylthio) ethanol are added to 200 parts of dimethylacetamide at room temperature for 1 hour. After stirring, the mixture was refluxed for 7 hours. Dimethylacetamide was removed from the resulting black brown solution by distillation under reduced pressure, and then dissolved in an ethyl acetate / toluene mixed solution. After separation by silica gel column chromatography (developing solvent: ethyl acetate / toluene), the fraction containing the desired product was concentrated. The concentrate was recrystallized with a toluene / hexane mixed solution to obtain 2.5 parts of a compound represented by the formula (15).

  Next, an electrophotographic photoreceptor was produced and evaluated as follows.

(Example of support)
An aluminum cylinder (JIS-A3003, aluminum alloy) was used as a support (conductive support). The length and diameter are shown in Table 1.

[Conductive layer preparation example 1]
214 parts of titanium oxide (TiO ₂ ) particles coated with oxygen-deficient tin oxide (SnO ₂ ) as metal oxide particles,
132 parts of phenol resin (monomer / oligomer of phenol resin) as a binding material (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content: 60% by mass), and
98 parts of 1-methoxy-2-propanol as solvent
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 resin particles (trade name: Tospearl 120, as a surface roughening agent) so as to be 10% by mass with respect to the total mass of the metal oxide particles and the binder material in the dispersion after removing the glass beads. Momentive Performance Materials, Inc., average particle size 2 μm) was added to the dispersion. Furthermore, silicone oil as a leveling agent (trade name: SH28PA, manufactured by Toray Dow Corning Co., Ltd.) so that the total mass of the metal oxide particles and the binder material in the dispersion is 0.01% by mass. ) Was added to the dispersion and stirred to prepare a coating solution for a conductive layer. This conductive layer coating solution was dip-coated on a support, and the resulting coating film was dried and thermally cured at 150 ° C. for 30 minutes to form a conductive layer 1 having a thickness of 30 μm.

[Conductive layer preparation example 2]
207 parts of titanium oxide (TiO ₂ ) particles coated with tin oxide (SnO ₂ ) doped with phosphorus (P) as metal oxide particles,
144 parts of a phenolic resin (trade name: Priorofen J-325) as a binding material, and
98 parts of 1-methoxy-2-propanol as solvent
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 resin particles (trade name: Tospearl 120) were added to the dispersion so that the total mass of the metal oxide particles and the binder material in the dispersion after removing the glass beads was 15% by mass. Furthermore, by adding and stirring the silicone oil (trade name: SH28PA) to the dispersion so as to be 0.01% by mass with respect to the total mass of the metal oxide particles and the binder material in the dispersion, A coating solution for a conductive layer was prepared. The conductive layer coating solution was dip-coated on a support, and the resulting coating film was dried and thermally cured at 150 ° C. for 30 minutes to form a conductive layer having a thickness of 30 μm.

[Conductive layer preparation example 3]
200 parts of barium sulfate fine particles (powder resistivity: 120 Ω · cm, tin oxide coverage: 40%) coated with oxygen-deficient tin oxide (SnO ₂ ) as metal oxide particles,
Titanium oxide (trade name: TITANIX JR, manufactured by Teika Co., Ltd., average particle size 0.27 μm),
166 parts of phenolic resin (trade name: Priorofen J-325) as a binder and 100 parts of 1-methoxy-2-propanol as a solvent are placed in a sand mill using 400 parts of glass beads with a diameter of 0.8 mm. The dispersion was performed under the conditions of a rotational speed of 2000 rpm, a dispersion treatment time of 3 hours, and a set temperature of cooling water of 18 ° C. to obtain a dispersion.

  Glass beads were removed from this dispersion with a mesh (aperture: 150 μm). Silicone resin particles (trade name: Tospearl 120) were added to the dispersion so that the total mass of the metal oxide particles and the binder material in the dispersion after removing the glass beads was 10% by mass. Furthermore, by adding and stirring the silicone oil (trade name: SH28PA) to the dispersion so as to be 0.01% by mass with respect to the total mass of the metal oxide particles and the binder material in the dispersion, A coating solution for a conductive layer was prepared. This conductive layer coating solution was dip-coated on a support, and the resulting coating film was dried and thermally cured at 145 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.

[Undercoat layer production example 1]
8.5 parts of the compound represented by formula (11) in Synthesis Example 1, 15 parts of blocked isocyanate compound (trade name: SBN-70D, manufactured by Asahi Kasei Chemicals Corporation), polyvinyl alcohol resin (trade name: KS-5Z) 0.97 parts, manufactured by Sekisui Chemical Co., Ltd.)
Zinc hexanoate (II) (trade name: zinc hexanoate (II), manufactured by Mitsuwa Chemicals Co., Ltd.) 0.15 part as a catalyst and mixing of 88 parts of 1-methoxy-2-propanol and 88 parts of tetrahydrofuran It was dissolved in a solvent to prepare an undercoat layer coating solution. The undercoat layer coating solution is dip-coated on the conductive layer, and the resulting coating film is heated at 170 ° C. for 20 minutes to be cured (polymerized), thereby forming the undercoat layer 1 having a thickness of 0.6 μm. Formed. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 2]
In subbing layer preparation example 1, the catalyst was changed to zinc 2-ethylhexanoate (trade name: bis (2-ethylhexanoic acid) zinc / mineral spirit solution (Zn: 15%), Wako Pure Chemical Industries, Ltd.) The undercoat layer 2 was formed in the same manner as in the undercoat layer preparation example 1 except that. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 3]
In the undercoat layer production example 1, 8.5 parts of the compound represented by the formula (11) was changed to the compound represented by the formula (12) of Synthesis Example 2 and changed to 15.7 parts of the blocked isocyanate compound. The undercoat layer 3 was formed in the same manner as in the undercoat layer preparation example 3. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer production example 4]
In the undercoat layer preparation example 3, the undercoat layer 4 was formed in the same manner as the undercoat layer preparation example 3 except that the compound represented by the formula (12) was changed to the compound represented by the formula (13) in the synthesis example 3. . Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 5]
In the undercoat layer preparation example 3, the undercoat layer 5 was formed in the same manner as the undercoat layer preparation example 3 except that the compound represented by the formula (12) was changed to the compound represented by the formula (14) in the synthesis example 4. . Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer production example 6]
In the undercoat layer preparation example 3, the undercoat layer 6 was formed in the same manner as the undercoat layer preparation example 3 except that the compound represented by the formula (12) was changed to the compound represented by the formula (15) of the synthesis example 5. . Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 7]
In the undercoat layer production example 2, 8.5 parts of the compound represented by the formula (11) was changed to 8.0 parts of the compound represented by the formula (12) and changed to 15.7 parts of a blocked isocyanate compound. The undercoat layer 7 was formed in the same manner as in the undercoat layer preparation example 2. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 8]
In the undercoat layer preparation example 7, the undercoat layer 8 was formed in the same manner as the undercoat layer preparation example 7, except that the compound represented by the formula (12) was changed to the compound represented by the formula (13). Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer production example 9]
In the undercoat layer preparation example 7, the undercoat layer 9 was formed in the same manner as the undercoat layer preparation example 7, except that the compound represented by the formula (12) was changed to the compound represented by the formula (14). Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 10]
An undercoat layer 10 was formed in the same manner as in the undercoat layer preparation example 7 except that the compound represented by the formula (12) in the undercoat layer preparation example 7 was changed to the compound represented by the formula (15). Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 11]
In the undercoat layer preparation example 1, the undercoat layer 11 was formed in the same manner as the undercoat layer preparation example 1 except that the blocked isocyanate compound was changed to trade name: SBN-70M, manufactured by Asahi Kasei Chemicals Corporation. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 12]
In undercoat layer preparation example 1, undercoat layer 12 was formed in the same manner as undercoat layer preparation example 1 except that the polyvinyl acetal resin was changed to trade name: BX-5, manufactured by Sekisui Chemical Co., Ltd. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 13]
In the undercoat layer preparation example 1, the undercoat layer 13 was formed in the same manner as the undercoat layer preparation example 1 except that the polyvinyl acetal resin was changed to trade name: BM-5, manufactured by Sekisui Chemical Co., Ltd. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 14]
In the undercoat layer preparation example 1, the undercoat layer 14 was formed in the same manner as the undercoat layer preparation example 1 except that the polyvinyl acetal resin was changed to trade name: KS-3, manufactured by Sekisui Chemical Co., Ltd. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 15]
In the undercoat layer preparation example 1, the undercoat layer 15 is the same as the undercoat layer preparation example 1 except that the compound represented by the formula (11) is changed to 8.0 parts and the blocked isocyanate compound is changed to 15.7 parts. Formed. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer production example 16]
In the undercoat layer preparation example 1, the undercoat layer 16 was formed in the same manner as the undercoat layer preparation example 1 except that the film thickness was changed to 0.5 μm. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 17]
In the undercoat layer preparation example 1, the undercoat layer 17 was formed in the same manner as the undercoat layer preparation example 1 except that the film thickness was changed to 0.7 μm. Table 2 shows the thickness and composition of the undercoat layer.

[Example 18 for producing undercoat layer]
In the undercoat layer preparation example 16, the undercoat layer 18 was formed in the same manner as the undercoat layer preparation example 16 except that 1-methoxy-2-propanol was changed to methanol and the film thickness was changed to 0.4 μm. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 19]
In the undercoat layer preparation example 16, the undercoat layer 19 was formed in the same manner as the undercoat layer preparation example 16 except that 1-methoxy-2-propanol was changed to ethanol. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 20]
In the undercoat layer preparation example 16, the undercoat layer 20 was formed in the same manner as the undercoat layer preparation example 16 except that a step of heating at 120 ° C. for 3 minutes was performed before heating at 170 ° C. for 20 minutes. Table 2 shows the thickness and composition of the undercoat layer.

[Undercoat layer preparation example 21]
10 parts of copolymer nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) and 30 parts of methoxymethylated nylon resin (trade name: Toresin EF30T, manufactured by Nagase ChemteX Corporation)
An undercoat layer coating solution was prepared by dissolving in a mixed solution of 500 parts of methanol and 250 parts of butanol.

  The undercoat layer coating solution was dip-coated on the conductive layer, and the resulting coating film was heated at 100 ° C. for 20 minutes to form an undercoat layer 18 having a thickness of 0.6 μm. Table 2 shows the thickness and composition of the undercoat layer.

[Charge generation layer preparation example 1]
Bragg angles (2θ ± 0.2 °) of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 in CuKα characteristic X-ray diffraction A crystalline form of hydroxygallium phthalocyanine crystal (charge generation material) having a peak at ° was prepared. 10 parts of this hydroxygallium phthalocyanine crystal, 5 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 260 parts of cyclohexanone are placed in a sand mill using glass beads having a diameter of 1 mm. Dispersed for 5 hours. Next, 240 parts of ethyl acetate was added thereto to prepare a charge generation layer coating solution. This charge generation layer coating solution was dip-coated on the undercoat layer, and the resulting coating film was dried at 95 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.18 μm.

[Charge transport layer preparation example 1]
8.1 parts of a charge transport material represented by the following formula (E-1), 0.9 part of a charge transport material represented by the following formula (E-2), and a structural unit represented by the following formula (F-1) as a resin Polycarbonate resin F1 (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) 10 parts, polycarbonate resin G1 having a structural unit represented by the following formula (G) (weight average molecular weight 40,000) 0.002 A coating solution for a charge transport layer was prepared by dissolving a part in 35 parts of dimethoxymethane, 45 parts of orthoxylene and 10 parts of methyl benzoate.

(In formula (G), 0.95 and 0.05 are copolymerization ratios of two structural units.)
This charge transport layer coating solution was dip-coated on the charge generation layer and dried at 120 ° C. for 1 hour to form a charge transport layer 1 having a thickness of 26 μm.

[Charge transport layer preparation example 2]
In the charge transport layer production example 1, the polycarbonate resin F1 and the polycarbonate resin G1 contain a structural unit represented by the following formula (C-1) and a structural unit represented by the following formula (C-2) in a ratio of 5: 5. 10 parts of a polyester resin C1 (weight average molecular weight 120,000), a structural unit represented by the following formula (F-1), a structural unit represented by the following formula (F-2), and a following formula (F-3) The polycarbonate resin F2 (weight average molecular weight 40,000) having the terminal structure shown was changed to 0.3 part. Otherwise, the charge transport layer 2 was formed in the same manner as in Charge Transport Layer Preparation Example 1. The total mass of the terminal structure represented by the formula (F-3) and the structural unit represented by the formula (F-1) with respect to the polycarbonate resin F2 is 30% by mass.

[Charge transport layer preparation example 5]
9 parts of a charge transport material represented by the following formula (E-1), 1 part of a charge transport material having a structure represented by the following formula (E-3),
As the resin, structural units represented by the following formulas (A-1), (A-2), (A-3), and (A-4), represented by the following formulas (B-1) and (B-2) 3 parts of a polyester resin A1 (weight average molecular weight 90,000) having a structural unit
7 parts of a polyester resin C1 (weight average molecular weight 120,000) containing the structural unit represented by the following formula (C-1) and formula (C-2) in a ratio of 5: 5 is 40 parts of dimethoxymethane and orthoxylene. A charge transport layer coating solution was prepared by dissolving in 60 parts of a mixed solvent. The charge transport layer coating solution was dip coated on the charge generation layer and dried at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 16 μm. The mass ratio of the structural units represented by the formulas (A-1), (A-2), (A-3), and (A-4) is 2.25: 0.75: 5.25: 1. And the mass ratio of the structural units represented by formula (B-1) and formula (B-2) is 3: 7. Furthermore, with respect to polyester resin A1, content of the structural unit shown by Formula (A-1), (A-2), (A-3), and (A-4) is 10 mass%, Content of the structural unit shown by Formula (B-1) and Formula (B-2) is 90 mass%.

  It was confirmed that the formed charge transport layer contained a domain structure containing the polyester resin A1 in a matrix containing the charge transport material and the polyester resin C1.

[Charge Transport Layer Preparation Examples 2 to 4, 6 to 27]
In the charge transport layer production examples 2 to 4 and 6 to 27, the charge transport material, polycarbonate resin, polyester resin A1 and polyester resin C1 shown in Table 3 are shown in Table 3, and the polyester resin C shown in Table 4 is used. Used and changed as shown in Table 5. Otherwise, charge transport layers 2 to 4 and 6 to 27 were formed in the same manner as in Charge Transport Layer Preparation Example 1.

  The numbers in the columns of Formula (A) and Formula (B) in Table 3 indicate the mass ratio of each structural unit. Formula (A) / Formula (B) in Table 3 represents the mass ratio of the structural unit represented by Formula (A) and the structural unit represented by Formula (B) in polyester resin A.

  The numbers in the column of formula (C) in Table 4 indicate the mass ratio of each structural unit.

  The numbers in the column of polyester resin A and polyester resin C in Table 5 indicate the mixing mass ratio of each resin. Resin (A) / resin (C) in Table 5 represents the mass ratio of polyester resin A and polyester resin C.

(Photosensitive member production examples 1 to 15, 26)
The electrophotographic photosensitive member was manufactured by combining the production examples of each layer with the electrophotographic photosensitive member. Specifically, electrophotographic photoreceptors were produced according to photoreceptor preparation examples 1 to 15 and 26 shown in Table 6.

[Evaluation Example 1]
The electrophotographic photoreceptor produced in the above photoreceptor preparation example was installed in a photoreceptor testing machine having a charging roller and an exposure device shown in FIG. 2 in an environment of a temperature of 15 ° C. and a humidity of 10% RH. Measurements were made. Details are as follows.

  The surface potential evaluation is performed by attaching a potential probe (model 6000B-7C: manufactured by Trek Japan Co., Ltd.) and measuring the potential at the center of the electrophotographic photosensitive member by a surface potential meter (model 344: manufactured by Trek Japan Co., Ltd.). Was measured using. As for the surface potential of the photoconductor, the initial dark portion potential (Vd), the initial bright portion potential (Vl), and the applied voltage and the amount of image exposure were set so that the rotational speed of the photoconductor per minute is as shown in Table 7. . The charge removal light was set to be 3 times the amount of light exposure. In the charging method in Table 7, DC indicates a method in which a DC voltage is applied to the roller, and AC / DC indicates a method in which a DC voltage and an AC voltage are superimposed and applied to the roller.

  FIG. 2 shows an outline of the apparatus. In FIG. 2, 1 is an electrophotographic photosensitive member, 2 is a charging roller, 4 is exposure, and 6 is exposure (static discharge light). 3 is a probe for measuring dark part potential, and 5 is a probe for measuring light part potential.

[Evaluation Examples 2 to 10 and Reference Evaluation Example 11]
Evaluation Example 1 except that the initial dark portion potential (Vd), the initial bright portion potential (Vl), the number of rotations of the photosensitive member per minute, the charging method, and the presence or absence of charge removal light were set as shown in Table 7 in Evaluation Example 1. Was set in the same manner. The results are shown in Table 7.

[Evaluation Example 12]
A laser beam printer (manufactured by Hewlett-Packard Co., Ltd.) in an environment of a temperature of 15 ° C. and a humidity of 10% RH is prepared by adjusting the diameter and length of the electrophotographic photosensitive member. The product was mounted on a modified machine having a trade name: CP4525dn). Then, the surface potential was measured. Details are as follows.

  The surface potential evaluation was performed by modifying the laser beam printer cyan process cartridge, mounting a potential probe (model 6000B-8) at the development position, and measuring the potential at the center of the electrophotographic photosensitive member with a surface potential meter ( Measured using model 344). For the surface potential of the photoconductor, the amount of image exposure was set so that the initial dark portion potential (Vd) was −500 V and the initial bright portion potential (Vl) was −100 V.

  In the laser beam printer (CP4525dn), the rotation speed of the electrophotographic photosensitive member per minute is 147 rotations, the diameter of the electrophotographic photosensitive member is 24 mm, the charging method is a method in which a DC voltage is applied to the roller, and other than the latent image formation. In this method, lightning is provided before charging. The transfer has a transfer system (ITB) having an intermediate transfer belt. The developing method is a contact developing method, and the toner used for the evaluation is a suspension polymerization toner.

  Using the above laser beam printer (CP4525dn), 10,000 full-color images (character images with a color printing rate of 1%) were output on A4 size plain paper.

(Examples 1-28 and Comparative Examples 1-2)
The electrophotographic photoreceptors produced in Photoreceptor Production Examples 1 to 15 were repeatedly used under the conditions of the evaluation examples shown in Table 8, and the difference between the bright part potential (Vlt) after repeated use and the initial bright part potential (Vl) was calculated. evaluated. The results are shown in Table 8.

    ΔVl = | Bright part potential after repeated use (Vlt) −Initial bright part potential (Vl) |

  The examples show that the effect of suppressing potential fluctuation is large.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 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

Claims (6)

A support, an undercoat layer provided on the support, a charge generation layer provided on the undercoat layer, and a charge transport layer provided on the charge generation layer, and the charge transport An electrophotographic photoreceptor in which the layer is a surface layer,
The undercoat layer contains a polymer of a composition containing a compound represented by the following formula (1),
An electrophotographic photoreceptor, wherein the charge transport layer contains a resin containing a silicon atom.

(In formula (1), R ^{101 to} R ¹⁰⁶ 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, substituted or unsubstituted A substituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, and one of the carbon atoms in the main chain of the alkyl group is O, S, NR ²⁰¹ (R ²⁰¹ is It represents a hydrogen atom or an alkyl group, and at least one of R ^{101 to} R ¹⁰⁶ is a monovalent group represented by the following formula (A).
The substituent of the substituted alkyl group is a group selected from the group consisting of an alkyl group, an aryl group, an alkoxycarbonyl group, and a halogen atom.
The substituent of the substituted aryl group is a group selected from the group consisting of a halogen atom, a nitro group, a cyano group, an alkyl group, and a halogenated alkyl group. )

(In Formula (A), at least one of α, β, and γ is a group having a substituent, and the substituent is selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group. At least one group, 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 at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkylene group may be replaced with O, S, or NR ³⁰¹ (R ³⁰¹ is a hydrogen atom or an alkyl group).
β represents a phenylene group, an alkyl-substituted phenylene group having 1 to 6 carbon atoms, a nitro group-substituted phenylene group, a halogenated phenylene group, or an alkoxy group-substituted phenylene group. These groups may have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent.
γ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, 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 at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent. One of the carbon atoms in the main chain of the alkyl group may be replaced with NR ⁴⁰¹ (R ⁴⁰¹ represents an alkyl group). ) The resin containing silicon atoms in the charge transport layer has a siloxane structure,
The electrophotographic photosensitive member according to claim 1, wherein the content of the siloxane structure in the resin is 10% by mass or more and 40% by mass or less. 3. The electrophotographic photosensitive member according to claim 1, wherein at least one of R ¹⁰⁵ and ^{106 in} the formula (1) is a monovalent group represented by the formula (A).   4. The electrophotography according to claim 1, wherein in the formula (A), at least one of α, β, and γ is a group having the substituent, and the substituent is a hydroxy group. 5. Photoconductor.   An electrophotographic photosensitive member according to any one of claims 1 to 4, and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, are integrally supported, and electrophotographic A process cartridge that is detachable from the main unit.   An electrophotographic apparatus comprising: the electrophotographic photosensitive member according to claim 1; a charging unit, an exposure unit, a developing unit, and a transfer unit.

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