JP2001083726A - Electrophotographic photoreceptor, its manufacturing method and electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor formed by successively laminating an undercoat layer and a charge generating layer on a conductive substrate and having superior electric characteristics and being freed of occurrence of problems at the time of forming laminate films and having wide freedom in designing of materials for the laminate films. SOLUTION: The undercoat layer is made of a copolymer comprising insulating parts and charge transferring parts, and it is preferred that this copolymer is made of a material hardly soluble in a solvent to be used for forming the photosensitive layer or this copolymer has a three-dimensional cross-linking structure and the charge transferring parts transfer a charge reverse to the charge transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor including a conductive substrate and a photosensitive layer, which has excellent lamination film forming properties and excellent electrical characteristics. Further, the present invention relates to a method for producing such an electrophotographic photoreceptor. Further, the present invention relates to an electrophotographic apparatus using the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art In recent years, electrophotographic technology has played a central role in the fields of copiers, printers, facsimiles, and the like because of its advantages such as high speed and high printing quality.

At present, various organic photoconductors (OPCs) for electrophotography have been proposed and put into practical use as photoconductive organic materials. Photoconductive organic materials are
It can be roughly classified into a hole-transporting material and an electron-transporting material, and a negatively-charged type in which a hole-transporting material is used for the charge-transporting layer and this is laminated on the charge-generating layer, It accounts for the majority of OPCs that are in practical use. In this case, when the photoconductive layer is formed directly on the conductive support, there are problems such as low chargeability and lack of stability of potential upon repetition. In addition, there were also problems such as peeling of the photoconductive layer due to lack of adhesion between the conductive support and the photoconductive layer, and occurrence of coating defects when applying the photoconductive layer on the conductive support. . Furthermore, unevenness of the surface of the conductive support causes unevenness in the thickness of the photoconductive layer, and as a result, image defects such as black spots and white spots occur.

As a means for solving these problems, an attempt has been made to provide an undercoat layer between a conductive support and a photoconductive layer. Examples of a material constituting the undercoat layer include thermoplastic resins such as polyvinyl acetate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyester, and polyamide, or thermosetting resins such as epoxy resin, melamine resin, urethane resin, and phenol resin. The use of resin is being considered (for example,
JP-A-48-47344, JP-A-52-2038
No. 6, JP-A-58-30757, JP-A-60-30
-225856, etc.).

When an undercoat layer containing these materials as a main component is used, it is necessary to increase the thickness of the undercoat layer in order to sufficiently bring out the effects of improving the above-described chargeability and image defects. is there. However, when the film thickness is large, there is a problem that the photosensitivity of the photoconductor is easily reduced and the residual potential is easily increased.

When an undercoat layer containing an organic metal compound such as a metal alkoxide or a metal chelate as a main component is used, a decrease in chargeability and image defects can be suppressed without causing a decrease in photosensitivity or an increase in residual potential. It is known that it is possible (Japanese Patent Publication No. 3-66663,
223439 and the like). However,
The undercoat layer using these organometallic compounds generally has a problem that it is easily affected by the environment such as humidity, and is deteriorated in a relatively short period of time because it is chemically unstable in a coating liquid state.

[0007] The undercoat layer is preferably electron-transporting in terms of its required function. It is considered that these problems can be avoided if an electron-transporting material having sufficient performance can be obtained. Can be As one approach,
Use of an undercoat layer in which a specific electron-transporting or electron-accepting low-molecular compound is added to a polymer resin has been studied (JP-A-55-142356, JP-A-5-142356).
9-170846 and the like).

However, when these low molecular weight compounds are easily soluble in an organic solvent, in the step of coating the photoconductive layer on the undercoat layer formed on the conductive support, the photoconductive layer which is the upper layer is used. In the case of a substance that leaches out into the layer and causes a decrease in the concentration in the undercoat layer, or conversely, is difficult to dissolve in an organic solvent, crystallization easily occurs in the undercoat layer. There is a problem that it is difficult to exhibit the effect of the above.

It has also been considered that the order of the charge generation layer and the charge transport layer is reversed to be used as OPC for positive charging. In this case, however, the charge generation layer having low mechanical strength becomes the upper layer. Therefore, it is necessary to form an overcoat in order to extend the life of the OPC. In this case as well, it is preferable that the material is electron-transporting in terms of function. However, since the electron-transporting material is generally difficult to dissolve in a solvent and is hardly compatible with a resin, the coating is uniform and has high mechanical strength. There was a drawback that a film was difficult to obtain.

Further, as a method of improving this, attempts have been made to polymerize an electron transporting material (see JP-A-52-12153 and JP-A-52-12154). At present, a material having sufficient performance in terms of adhesiveness, strength and the like has not yet been obtained.

On the other hand, a positively charged type in which an electron transporting material is used for the charge transporting layer and laminated on the charge generating layer, or a negatively charged OPC in which the order of the charge generating layer and the transporting layer is reversed. In this case, it is preferable that the charge transporting material in the undercoat layer has a hole transporting property, but at present it has hardly been studied.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances in the prior art, and has excellent electrical characteristics, has no problem during lamination film formation, An object of the present invention is to provide an electrophotographic photosensitive member having a high degree of freedom in material design.

[0013]

Means for Solving the Problems The present inventors have made intensive studies on charge transporting materials and polymer materials, and as a result,
A charge transporting portion (block) and an insulating portion (block) are formed by a block copolymerization and / or graft copolymerization technique in which a plurality of portions (blocks) having a desired function are connected by a covalent bond. Have been found to have excellent overall properties as an undercoat layer material and are suitable, and have completed the present invention. By using this copolymer, an underlayer material having multiple functions can be obtained without impairing each function.

That is, the present inventors have the following <1> to <2>
1> Invention was found. <1> An electrophotographic photoreceptor having an undercoat layer on a conductive substrate, and at least a photosensitive layer containing a charge generation material and a charge transport material on the undercoat layer, wherein the material of the undercoat layer is insulating. A copolymer comprising a conductive portion and a charge transporting portion, wherein the copolymer preferably comprises a material in which the insulating portion of the copolymer is hardly soluble in the solvent used when applying the photosensitive layer. An electrophotographic photoreceptor wherein the charge transporting portion transports a charge opposite to that of the charge transporting material.

<2> In the electrophotographic photoreceptor of the above <1>, the insulating portion preferably has a carboxylic acid. <3> In the electrophotographic photoreceptor of the above item <1>, the chain constituting the insulating portion preferably has a maleic anhydride skeleton. <4> In the electrophotographic photosensitive member according to <1>, the insulating portion preferably has a fluorine atom.

<5> An electrophotographic photoreceptor having at least a subbing layer on a conductive substrate and a photosensitive layer containing a charge generating material and a charge transporting material on the subbing layer,
An electrophotographic photoreceptor, wherein the material of the undercoat layer is a copolymer containing an insulating portion and a charge transporting portion and having a crosslinked structure, wherein the charge transporting portion transports charges opposite to the charge transporting material. .

<6> In the electrophotographic photoreceptor according to the above <5>, the crosslinked structure comprises the insulating portion of the first copolymer and the second portion.
It is preferable to include a structure obtained by cross-linking the copolymer with the insulating portion. The first copolymer and the second copolymer may be the same or different. <7> In the electrophotographic photoreceptor of the above item <5> or <6>, the copolymer may form a crosslinked structure via a crosslinkable functional group. <8> In the electrophotographic photosensitive member according to any one of the above items <5> to <7>, the first insulating portion and the second insulating portion have a functional group, and a crosslinked structure is formed by a condensation reaction of the functional group. Is good.

<9> In the electrophotographic photosensitive member according to any one of the above items <5> to <8>, the insulating portion preferably has a hydroxy group, and the copolymer is preferably crosslinked using a polyvalent isocyanate compound. <10> In the electrophotographic photosensitive member according to any one of the above items <5> to <8>, the insulating portion preferably has an alkoxysilyl group.

<11> In the electrophotographic photosensitive member according to any one of the above items <1> to <10>, the insulating portion preferably contains a polymer derived from a vinyl monomer. <12> In the electrophotographic photoreceptor of the above item <11>, the vinyl monomer is represented by the following general formula (I-α) or (I-α).
It preferably contains at least one compound represented by β).

[0020]

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In the general formula (I-α) or (I-β), R ¹
To R ³ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ⁴ is a substituted alkyl group having 3 or more carbon atoms containing a fluorine atom, a substituted aryl group having 6 or more carbon atoms containing a fluorine atom, a substituted alkyloxycarbonyl group having 3 or more carbon atoms containing a fluorine atom, and a carbon atom containing a fluorine atom. A substituted or unsubstituted cyanoalkyl group, a substituted or unsubstituted cyanoaryl group, or a substituted or unsubstituted carboxyl group; Shows an acid group. Z represents an oxygen atom or a substituted or unsubstituted imino group.

<13> The vinyl monomer contains at least one kind of a compound represented by the following formula (II) and at least one kind of a compound having a crosslinkable functional group represented by the following formula (III): The electrophotographic photosensitive member according to <11>.

[0023]

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In the general formula (II), R ^{11 to} R ¹³ each independently represent a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl or aryl group, and R ¹⁴ represents a halogen atom, or a substituted or unsubstituted group. Alkyl group, aryl group, alkoxy group, acyl group, acyloxy group,
Or an alkoxycarbonyl group. In the general formula (III), R ^{15 to} R ¹⁷ each independently represent a hydrogen atom,
A halogen atom or a substituted or unsubstituted alkyl or aryl group; R ¹⁸ is a chlorosulfone group, a carboxyl group, a hydroxy group, a mercapto group, a nitrile group, an isocyanate group, an amino group, an epoxy group or an alkoxysilyl group; A substituted alkyl group, substituted aryl group, substituted alkoxy group, substituted acyl group, substituted acyloxy group, or substituted alkoxycarbonyl group is shown.

<14> In the electrophotographic photosensitive member of <1> to <13>, the copolymer is a block copolymer and / or
Or it is good to be a graft copolymer. <15> In the electrophotographic photosensitive member according to any one of the above items <1> to <14>, the charge transporting portion preferably contains a repeating unit containing a triarylamine structure. <16> In the electrophotographic photoreceptor of the above item <15>, the triarylamine structure preferably includes a structure represented by the following general formula (IV).

[0026]

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In the general formula (IV), Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group, and X ¹ represents a divalent hydrocarbon group having an aromatic ring structure or a hetero atom-containing hydrocarbon. X ² and X ³ each independently represent a substituted or unsubstituted arylene group; L ¹ represents a divalent hydrocarbon group or a hetero atom-containing hydrocarbon group which may have a branched or ring structure; , M and n each represent an integer selected from 0 or 1.

<17> The electrophotographic photosensitive member according to <16> above
In the above, X of the above general formula (IV) ¹Is replaced or unplaced
It may be a substituted biphenylene group. <18> The electrophotographic photosensitive member according to <15>, wherein
The charge transporting moiety having a riarylamine structure is as follows:
Repeating at least one of the structures represented by the general formula (V)
It is good to have as a unit.

[0029]

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In the general formula (V), Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group, and L ² represents a trivalent hydrocarbon group having an aromatic ring structure or a heteroatom-containing hydrocarbon. Represents a group.

<19> An electrophotographic apparatus having the electrophotographic photosensitive member according to <1> to <18>. <20> a step of preparing a coating liquid containing a copolymer containing an insulating part and a charge transporting part, a step of applying the coating liquid on a conductive substrate to prepare an undercoat layer, and A method for producing an electrophotographic photoreceptor, comprising a step of preparing a photosensitive layer containing a charge generation material and / or a charge transport material on the undercoat layer by a wet coating method after the undercoat layer preparation step.

<21> A step of preparing a coating solution containing a copolymer having an insulating portion and a charge transporting portion and having a crosslinkable functional group, and coating the coating solution on a conductive substrate Preparing the undercoat layer by crosslinking the copolymer after or during the coating step, and a photosensitive layer containing a charge generating material and / or a charge transport material after the undercoat layer preparing step. A method for producing an electrophotographic photoreceptor, comprising the step of: preparing on the undercoat layer by a wet coating method.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The electrophotographic photoreceptor of the present invention has a conductive substrate, an undercoat layer on the conductive substrate, and at least a photosensitive layer on the undercoat layer. The photosensitive layer may have any structure as long as it contains a charge generating material and a charge transporting material. For example, the photosensitive layer may have a single-layer structure, a stacked structure, or another structure.
A surface protective layer may be further provided on this photosensitive layer.

The structure of the electrophotographic photosensitive member of the present invention will be described below with reference to the drawings. 1 and 2 are schematic views showing a cross section of the electrophotographic photosensitive member of the present invention. FIG.
1, an undercoat layer 2 containing a copolymer is provided on a conductive substrate 1, and a photosensitive layer 3 containing a charge generation material and a charge transport material is further provided on the undercoat layer 2. In FIG.
A surface protective layer 8 is further provided on the photosensitive layer 3.

FIGS. 3 and 4 are schematic views showing a cross section of an electrophotographic photosensitive member according to another embodiment of the present invention. In FIG. 3, an undercoat layer 2 containing a copolymer is provided on a conductive substrate 1, and a photosensitive layer 3 including a charge generation layer 4 and a charge transport layer 5 is provided on the undercoat layer 2. . In FIG. 4, a surface protective layer 8 is further provided.

FIGS. 5 and 6 are schematic views showing a cross section of an electrophotographic photosensitive member according to another embodiment of the present invention. In FIG. 5, an undercoat layer 2 containing a copolymer is provided on a conductive substrate 1, a charge generation layer 4 is provided thereon, and a first charge transport layer 6 and a second charge transport layer 7 are provided. The photosensitive layer 3 includes the charge generation layer 4, the first charge transport layer 6, and the second charge transport layer 7. In FIG. 6, a surface protection layer 8 is further provided.

Hereinafter, the conductive substrate will be described in order. The conductive substrate that can be used in the present invention may be opaque or substantially transparent.

Examples of the conductive substrate include metals such as aluminum, nickel, chromium, and stainless steel; aluminum, titanium, nickel, chromium, stainless steel, gold,
Plastic films and glasses provided with thin films such as vanadium, tin oxide, indium oxide, and ITO; and papers, plastic films and glasses coated or impregnated with a conductivity-imparting agent.

These conductive substrates can be used in an appropriate shape such as a drum shape, a sheet shape, and a plate shape, but are not limited thereto. Further, if necessary, various kinds of processing can be performed on the surface of the conductive substrate within a range that does not affect the image quality. For example, surface oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed.

The electrophotographic photoreceptor of the present invention comprises an undercoat layer on the conductive substrate, and a photosensitive layer on the undercoat layer. When the photosensitive layer is provided on the undercoat layer, the material of the photosensitive layer is dispersed or dissolved in a solvent and applied onto the undercoat layer. In the present invention, in order to prevent the material of the undercoat layer from being eluted or dissolved or leached by the solvent,
This material was made of a copolymer containing an insulating portion and a charge transporting portion.

In particular, as a first aspect of the present invention, the copolymer, preferably the insulating portion of the copolymer, is made to have poor solubility in the solvent of the photosensitive layer material. Also, as a second aspect of the present invention, the copolymer has a cross-linked structure so that the entire copolymer has poor solubility in a solvent of the photosensitive layer material.

In the present invention, the copolymer is preferably a block copolymer and / or a graft copolymer having an insulating portion and a charge transporting portion. In the present specification, the “portion” in the insulating “portion” and the charge transporting “portion” refers to each “block” of the block copolymer, and the main chain “portion” or branched “portion” of the graft copolymer. Is included.

The copolymer may be connected in any form. That is, assuming that the charge transporting portion is A and the insulating portion is B, AB type, ABA type, BA
Type B, (AB) _n type, (AB) _n type A, and B (AB)
_{an n-} type block copolymer, a charge-transporting portion having a main chain, a graft copolymer having an insulating portion as a side chain, an insulating portion having a main chain, a graft copolymer having a charge-transporting portion as a side chain, Alternatively, a block-graft copolymer obtained by grafting A and / or B to a side chain of a block copolymer such as an ABA type copolymer may be used.

As is well known in the field of polymer blends and polymer alloys, different polymers are generally incompatible with each other, and their mixtures and block copolymers or graft copolymers have a phase-separated state. take. Generally, in a mere mixture, that is, a polymer blend, the phase separation scale is macroscopic to several μm or more (macrophase separation). On the other hand, the block copolymer and the graft copolymer in which each component is connected by a covalent bond give a phase separation state composed of fine domains of submicron or less (microphase separation). It is known that the scale of phase separation in block copolymers and graft copolymers is generally the same dimension as the average length of each block, and is approximately proportional to the molecular weight. The copolymer used in the present invention also generally takes a microphase separated state. However, the copolymer of the present invention does not always take a microphase-separated state, and some copolymers exhibit compatibility and do not cause phase separation depending on the combination of each block.

In general, the phase separation state in a phase-separable block or a graft copolymer depends on the type of constituent blocks,
The most thermodynamically stable structure exists depending on the molecular weight, the composition ratio of both blocks, and the like. In the copolymer consisting of A block and B block, A / B
It depends only on the composition ratio. As the A / B ratio increases, A is a spherical domain and B is a matrix, A is a rod-shaped domain and B
Is matrix, A / B alternating layer, B is rod-shaped domain, A
Is a matrix, B is a spherical domain and A is systematically changed to a matrix. However, when a film is formed by a wet coating method, the phase separation state can be arbitrarily controlled depending on the solvent used, the drying speed, and the like. For example, A / B
Even when the ratio is large and thermodynamically, B has a spherical domain and A has a matrix structure, if a solvent that is a good solvent for B and a poor solvent for A is selected as a coating solvent, , A is a spherical domain and B is a matrix. When a good solvent for both A and B is used and the solvent is rapidly removed, a phase-separated structure (modulated structure) frozen in a spinodal decomposition state can be obtained. Further, when a polymer having a large A / B ratio and having a structure in which B is a spherical domain and A is a matrix is thermodynamically added with a polymer compatible only with B, the amount of addition increases. As a result, the B spheres enlarge, and finally, a phase-separated structure in which A is a globular domain, and a polymer compatible with B and B alone becomes a matrix.

In this specification, the term "insulating" means that the transport energy level is far from the transport energy level of the main transport charge, and that the transport charge is substantially injected at the ordinary electric field strength. Rather, it is effectively in an electrically insulating state for the main charge.

The resistance of the insulating portion in the copolymer of the present invention is preferably 10 ¹³ ohm · cm or more, particularly 10 ¹⁴ ohm · cm.
It is preferably at least ohm · cm. When the resistance value of the insulating portion decreases, transport charges penetrate into the insulating portion,
Problems such as an increase in residual potential and a decrease in repetition stability occur. Incidentally, the electrical resistivity of the insulating portion in the copolymer,
It is difficult to measure directly. Therefore, the resistance of the insulating portion in the copolymer can be substituted by the electric resistivity of a polymer having the same structure as the insulating portion to be treated.

In this specification, the term “charge transporting property” is used.
Means a state in which transport charges can be injected by the intensity of the surrounding electric field. The charge transporting portion of the copolymer of the undercoating layer preferably transports charges opposite to the charge transporting material in the photosensitive layer which is the upper layer of the undercoating layer. The charge mobility of the charge transporting portion in the copolymer of the present invention is one factor that governs the response speed of the electrophotographic photoreceptor, and the higher the mobility, the better. Therefore, these high mobility ones
It is suitably used for a high-speed or small electrophotographic apparatus having a short time from exposure to development. In the electrophotographic apparatus of the present invention, it is preferably 10 ^-8 cm ² / Vs or more at least in an electric field intensity range used for development. More preferably, it is at least 10 ⁻⁷ cm ² / Vs. Incidentally, it is difficult to directly measure the charge mobility of the charge transporting portion. Therefore, the charge mobility of the charge transporting portion can be replaced by the charge mobility of the charge transporting polymer having the same structure as the target charge transporting portion. Mobility measurement is a common practice in the industry, Time-of-Fl
It can be performed by the light method, and the electric field strength is 5 V / μm
Is represented by the value of

Hereinafter, the first and second aspects of the present invention will be described in detail. First, the first aspect of the present invention will be described. In the first aspect of the present invention, the material of the undercoat layer is a copolymer containing an insulating portion and a charge transporting portion, wherein the copolymer is preferably an insulating portion of the copolymer. A copolymer that is hardly soluble in a solvent used for coating the photosensitive layer is used. By using this copolymer, the resistance to the solvent used when applying the photosensitive layer can be increased without impairing the function of the charge transporting portion.

In the present specification, "slightly soluble in a solvent used for coating the photosensitive layer" means that it is hardly soluble in a specific solvent used for coating the photosensitive layer. It may be dissolved in a solvent. The solvent used for coating the photosensitive layer will be described later.

The copolymer of the present invention, preferably, the insulating portion of the copolymer has a group that is hardly soluble in the solvent used when coating the photosensitive layer. Any group which exhibits poor solubility in a solvent used for coating the photosensitive layer may be used as the group exhibiting poor solubility. For example, a fluorine atom, an amide group, a cyano group, a carboxylic acid group,
And those having an acid anhydride structure and those having an acid amide structure. These poorly soluble groups may be present in one or both of the charge transporting portion and the insulating portion, but are preferably present mainly in the insulating portion, particularly preferably only in the insulating portion. The presence thereof is less likely to affect the charge transporting property formed by the charge transporting portion, and is advantageous in electrical characteristics.

It is particularly preferable that the hardly soluble group contains a carboxylic acid group or a fluorine atom or a maleic anhydride skeleton as a main chain. Since these polar groups are hardly soluble in solvents other than the solvent containing the polar groups, they can be preferably used when applying the upper photosensitive layer. In addition, mechanical strength and electrical properties are also excellent.

As described above, the poorly soluble group used in the present invention only needs to be contained in the charge transporting portion and / or the insulating portion. When the insulating portion has a poorly soluble group, the insulating portion may be formed of a portion obtained by polymerizing a repeating unit having a hardly soluble group and a portion obtained by polymerizing a repeating unit having no hardly soluble group. Further, the insulating portion may be formed only of a portion obtained by polymerizing a repeating unit having a poorly soluble group.

In particular, when the hardly soluble group is present only in the insulating portion, the composition ratio of (a repeating unit having a hardly soluble group in the insulating portion) :( a repeating unit having no hardly soluble group) is 1: 1. A range of 20 to 10: 1 is preferable, and a range of 1: 5
A range of 3: 1 is more preferred. If the composition ratio of the repeating unit having a poorly soluble group is too high, the resulting undercoat layer tends to be brittle, and if the composition ratio of the repeating unit having a poorly soluble group is too low, the mechanical properties of the obtained undercoat layer are low. The strength tends to deteriorate.

The copolymer of the present invention can be used to form a block copolymer and / or a graft copolymer comprising a charge transporting portion and an insulating portion. Can be obtained by random copolymerization or block copolymerization of a repeating unit having the formula: Further, it can also be obtained by generating a hardly soluble group in a block copolymer and / or a graft copolymer comprising a charge transporting portion having no hardly soluble group and an insulating portion.

As the insulating portion in the copolymer of the present invention,
Any material such as polycarbonate, polyarylate, polyester, polysulfone, polymethyl methacrylate, and polyurethane may be used, but the mechanical strength, flexibility, visible light and infrared light transmittance, chemical stability, insulation, etc. And preferably a polymer of a vinyl monomer.

In particular, it is preferable to use, as the vinyl monomer, a monomer obtained by polymerizing at least one compound represented by the following formula (I-α) or (I-β). Further, a product obtained by copolymerizing a vinyl monomer represented by the following general formula (II) and at least one vinyl monomer represented by the following general formula (I-α) or (I-β) is used. Is preferred.

[0058]

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Formula (I-α) or (I-β)
Wherein R ^{1 to} R ³ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Specific examples of a substituted or unsubstituted alkyl group or aryl group include
Examples include a methyl group, an ethyl group, a methoxy group, a chloromethyl group, a phenyl group, and a tolyl group.

In the above general formula (I-β), R ⁴ is a substituted alkyl group having 3 or more carbon atoms containing at least one fluorine atom, a substituted aryl group having 6 or more carbon atoms containing at least one fluorine atom, A substituted alkyloxycarbonyl group having 3 or more carbon atoms containing one fluorine atom, a substituted alkyloxy group having 3 or more carbon atoms containing at least one fluorine atom, a cyclic or acyclic amide group, a cyclic or acyclic cyano group, A substituted or unsubstituted cyanoalkyl group, a substituted or unsubstituted cyanoaryl group,
Alternatively, it is selected from a substituted or unsubstituted carboxylic acid group. The above substituted alkyl group may have a branched chain or a ring structure, and preferably has 1 to 20 carbon atoms.
Examples of the substituted aryl group include a phenyl group, a naphthyl group, and pyrenyl. Z is selected from an oxygen atom or a substituted or unsubstituted imino group.

[0061]

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In the general formula (VI), R ^{5 to} R ⁷ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Specific examples of the substituted or unsubstituted alkyl group or aryl group include a methyl group, an ethyl group, a methoxy group, a chloromethyl group, a phenyl group, a tolyl group, and the like.

In the above general formula (VI), R ⁸ represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkoxyl group, It is selected from a substituted or unsubstituted acyl group, a substituted or unsubstituted acyloxy group, and a substituted or unsubstituted alkoxycarbonyl group. The alkyl group, alkoxy group, alkoxyl group, acyl group, acyloxy group, and alkoxycarbonyl group preferably have 1 to 18 carbon atoms. Examples of the aryl group include a phenyl group, a naphthyl group, and pyrenyl.

In the first aspect of the present invention, specific examples represented by the above general formulas (I-α) and (I-β), which are contained as a repeating unit in the insulating portion, are shown in Tables 1 and 2 below. Table 2
Shown in Table 3 below shows specific examples represented by the general formula (VI). These examples are merely specific examples, and the present invention is not limited to these examples.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

[Table 4]

[0069]

[Table 5]

[0070]

[Table 6]

[0071]

[Table 7]

[0072]

[Table 8]

[0073]

[Table 9]

Next, the second aspect of the present invention will be described. In the second aspect of the present invention, a copolymer containing an insulating portion and a charge transporting portion and having a crosslinked structure is used as a material of the undercoat layer. In particular, it is preferable that the molecular structure of the copolymer be made three-dimensional by the crosslinked structure.

The crosslinked structure may be formed by crosslinking any part of the copolymer. For example, a structure in which the insulating portion of the first copolymer and the insulating portion of the second copolymer are cross-linked, and the charge transporting property of the insulating portion of the first copolymer and the second copolymer. A structure that crosslinks the part, or the first
Any structure may be used to crosslink the charge transporting portion of the copolymer and the charge transporting portion of the second copolymer. Here, the first copolymer and the second copolymer may be the same or different.

A structure in which the insulating portion of the first copolymer and the insulating portion of the second copolymer are cross-linked is preferable.
By using a copolymer in which insulating portions are cross-linked, particularly a copolymer in which the molecular structure is three-dimensionalized by cross-linking, a solvent used when coating the photosensitive layer without impairing the function of the charge transporting portion. Resistance can be increased.

In the following description, the term “copolymer containing an insulating portion and a charge transporting portion and containing a crosslinked structure” is simply referred to as “crosslinked copolymer”. `` Polymer '', `` a copolymer containing an insulating portion and a charge transporting portion and having a crosslinkable functional group '' simply `` copolymer having a crosslinkable functional group '',
Further, “a copolymer containing an insulating portion and a charge transporting portion and not yet crosslinked” may be simply abbreviated as “a copolymer before crosslinking”.

In the preparation of a cross-linked copolymer, the cross-linking reaction proceeds gradually, and a portion where the molecular structure is made three-dimensional may occur during the preparation of the copolymer. For this reason, in this specification, "the molecular structure is not three-dimensionalized" is not "the molecular structure is not three-dimensionally 100%", but is not that the copolymer is in a coating liquid or the like. Means that it is in a range in which fluidity is maintained to such an extent that it can be substantially uniformly dissolved and applied. Therefore, when a copolymer having a crosslinkable functional group is prepared, even if a part of the copolymer is crosslinked, it is included in a state where the molecular structure is not three-dimensional.

The crosslinked copolymer is formed into a film from a coating liquid in which a copolymer before molecular crosslinking whose molecular structure is not three-dimensionally mixed and, if necessary, a crosslinking agent and / or a catalyst. It can be obtained by performing a treatment for crosslinking accordingly. The crosslinked copolymer preferably contains the copolymer as a main component of the binder resin in an amount of 30% by weight or more. It is more preferably at least 50% by weight, further preferably at least 70% by weight.

The crosslinkable functional groups of the copolymer before crosslinking include various crosslinkable functional groups. For example, Crosslinking Agent Handbook (Taiseisha, Showa 56
Years), synthesis and application of reactive polymers (CMC, 19
(1989)) and the like. Examples include hydroxy, alkoxysilyl, epoxy, carboxyl, halogen, isocyanate, mercapto, chlorosulfone, amino, amide, tertiary amino, nitrile, and pyridine groups, and Examples thereof include those having an acid anhydride structure and those having a double bond.

These crosslinkable functional groups may be present in either or both of the charge transporting portion and the insulating portion, but are preferably present mainly in the insulating portion, particularly preferably in the insulating portion alone. It is better to exist. Because the charge transporting portion has little effect on the charge transporting property,
This is because it is advantageous in electrical characteristics.

The crosslinking reaction requires a crosslinking agent and / or a catalyst and crosslinking conditions depending on the reaction. Cross-linking reactions, cross-linking agents, catalysts and cross-linking conditions, and combinations thereof, are described in literatures such as Cross-Linking Agent Handbook (Taiseisha, 1981), Synthesis and Application of Reactive Polymers (CMC, 1989). Any type can be used as long as the crosslinkable functional group crosslinks.

As a crosslinking agent, for example, a sulfur compound, an organic peroxide, a polyvalent phenol resin, a polyvalent amino resin,
Polyvalent halogen compound, polyvalent amine compound, polyvalent azo compound, polyvalent isocyanate compound, polyvalent silyl isocyanate compound polyvalent epoxy compound, silane compound, titanate compound, polyvalent carboxylic acid compound, acid Anhydrides and the like. As organic peroxides, peroxyesters such as t-butyl peroxyisopropyl monocarbonate and t-butyl peroxybenzoate, ketone peroxides, peroxy ketals,
Examples include hydroperoxides, dialkyl peroxides, diacyl peroxides, and peroxydicarbonates.

A mixture of these cross-linking agents in advance with the copolymer before cross-linking is applied, followed by a cross-linking reaction, or after applying the copolymer before cross-linking, spraying or dipping these cross-linking agents. Cross-linking can be effected by contact with steam.

It is particularly preferred that the crosslinkable functional group is a hydroxy group and that the crosslinking agent is a polyvalent isocyanate compound. In this case, as a catalyst, metal acetate, metal chloride, copper sulfate, di-n-butyltin dilaure-
Can be added. Further, it is preferable to heat to promote crosslinking.

As a polyvalent isocyanate compound, it is more desirable to use a derivative obtained from an isocyanate monomer or a modified polyisocyanate such as a prepolymer. Examples thereof include an adduct modified product obtained by adding an isocyanate to a polyol having 3 or more functional groups, a biuret modified product obtained by modifying a compound having a urea bond with an isocyanate compound, an allophanate modified product obtained by adding an isocyanate to a urethane group, and an isocyanurate modified product And the like, and a carbodiimide-modified product is also used. In particular, the biuret-modified hexamethylene diisocyanate and the isocyanurate-modified hexamethylene diisocyanate represented by the following structural formulas (A-1) and (A-2) have mechanical strength and electric strength. It shows particularly excellent characteristics in terms of characteristics.

[0087]

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Further, as other isocyanate compounds,
For example, tolylene diisocyanate (TDI), diphenylmethane diisosocyanate (MDI), 1,5-naphthylene diisocyanate, tolidine diisocyanate, 1,6-
Hexamethylene diisocyanate, xylene diisocyanate, lysine isocyanate, tetramethyl xylene diisocyanate, 1,3,6-hexamethylene triisocyanate, lysine ester triisocyanate, 1,6,11-
Undecane triisocyanate, 1,8-isocyanate
General isocyanate monomers such as -4-isocyanatemethyloctane, triphenylmethanetriisocyanate, and tris (isocyanatephenyl) thiophosphate.

Blocked isocyanates which are included in the above-mentioned modified polyisocyanate and reacted with a blocking agent for temporarily masking the activity of the isocyanate group can also be preferably used. This is preferable from the viewpoint of extending the pot life of the coating liquid.

Further, silane compounds, titanate compounds and the like can be used as a crosslinking agent. Specific examples of these, vinyltrimethoxysilane, vinyltriethoxysilane, tris- (β-methoxyethoxy) vinylsilane, vinyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, β-mercaptoethyltrimethoxysilane, γ-chloropropyltrimethoxysilane, isopropyl tristearoyl titanate, isopropyl methacrylisostearoyl titanate, etc. Known compounds.

Further, the copolymer before crosslinking has a crosslinkable functional group, and a crosslinked copolymer can be obtained by a condensation reaction between the functional groups. In this case, it is not necessary to add a cross-linking agent, and it is possible to eliminate an adverse effect on the charge transporting property caused by the cross-linking agent remaining in the charge transporting portion. In particular, when the cross-linked site of the cross-linked copolymer is mainly present only in the insulating portion, and when the cross-linkable functional group of the copolymer before cross-linking is mainly present only in the insulating portion,
Since the charge transporting portion has no cross-linking agent remaining and the charge transporting portion has neither a cross-linking site nor an uncross-linked cross-linkable functional group, the charge transporting property is not impaired, which is particularly preferable.

Examples of the functional groups capable of undergoing a condensation reaction between the functional groups and thereby forming a crosslinked structure include alkoxysilyl groups, isocyanate groups, a hydroxyl group and an isocyanate group. In particular, an alkoxysilyl group is preferable because it has appropriate reactivity, but is advantageous for synthesis and handling. Further, a crosslinking reaction can be easily caused, and alcohol generated by condensation does not remain in the photosensitive layer by being vaporized, which is preferable.

When the crosslinkable functional group is an alkoxysilyl group, an acid such as acetic acid or hydrochloric acid, an alkali, or an organometallic compound can be added as a catalyst, and water may be further added. Heating can be performed to promote crosslinking.

As described above, the crosslinkable functional group of the copolymer before crosslinking used in the present invention may be contained in either or both of the charge transporting portion and the insulating portion. The insulating portion may be formed of a block in which a repeating unit having a crosslinkable functional group is polymerized and a block in which a repeating unit having no crosslinkable functional group is polymerized. Further, the insulating portion may be formed only of a block in which a repeating unit having a crosslinkable functional group is polymerized.

In particular, when the crosslinkable functional group is present only in the insulating portion, the (repeating unit having a crosslinkable functional group) and the (repeating unit having no crosslinkable functional group) in the insulating portion may be used. The composition ratio is preferably in the range of 1:20 to 10: 1, and more preferably in the range of 1: 5 to 3: 1. If the composition ratio of the repeating unit having a crosslinkable functional group is too high, the composition tends to become brittle, and if the composition ratio of the repeating unit having a crosslinkable functional group is too low, the mechanical strength tends to deteriorate.

As the insulating portion in the copolymer on the second surface of the present invention, the same as in the first surface, polycarbonate,
Polyarylate, polyester, polysulfone, polymethyl methacrylate, polyurethane, etc., may be anything, but in terms of mechanical strength, flexibility, visible and infrared light transmission, chemical stability, insulation, etc. It is preferred to be composed of a polymer of a vinyl monomer.

In particular, in the second aspect of the present invention, as the vinyl monomer, those obtained by polymerizing at least one vinyl monomer represented by the following general formula (II) are preferable. Further, a vinyl monomer having a crosslinkable functional group represented by the following general formula (III) and a vinyl monomer represented by the following general formula (II) are preferable.

[0098]

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In the general formula (II), R ^{11 to} R ¹³ are each independently selected from a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl or aryl group.
Specific examples of the substituted or unsubstituted alkyl group or aryl group include a methyl group, an ethyl group, a methoxy group, a chloromethyl group, a phenyl group, a tolyl group and the like.

In the above general formula (II), R ¹⁴ is selected from a substituted or unsubstituted alkyl group, aryl group, alkoxy group, acyl group, acyloxy group and alkoxycarbonyl group. The alkyl group, the alkoxy group, the acyl group, the acyloxy group, and the alkoxycarbonyl group preferably have 1 to 18 carbon atoms. Examples of the aryl group include a phenyl group, a naphthyl group, and pyrenyl.
Examples of the substituent include a halogen atom, a phenyl group, a hydroxy group, an amino group, an isocyanate group, an epoxy group, and an alkoxysilyl group.

In the above formula (III), R ^{15 to} R ¹⁷ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Specific examples of the substituted or unsubstituted alkyl group or the substituted or unsubstituted aryl group include a methyl group, an ethyl group, a methoxy group, a chloromethyl group, a phenyl group, a tolyl group, and the like.

In the above formula (III), R ¹⁸ is a substituted alkyl group substituted by a chlorosulfone group, a carboxyl group, a hydroxy group, a mercapto group, a nitrile group, an isocyanate group, an amino group, an epoxy group or an alkoxysilyl group. , A substituted aryl group, a substituted alkoxy group, a substituted acyl group, a substituted acyloxy group, or a substituted alkoxycarbonyl group. The substituted alkyl group may have a branched or cyclic structure, but preferably has 1 to 20 carbon atoms. Examples of the substituted aryl group include a phenyl group, a naphthyl group, and pyrenyl.

In the second aspect of the present invention, specific examples represented by the above general formula (II), which are contained as a repeating unit in the insulating portion, are shown in Table 4 below. In addition, the general formula (I
Specific examples represented by II) are shown in Table 5 below. These examples are merely specific and are not limiting.

[0104]

[Table 10]

[0105]

[Table 11]

[0106]

[Table 12]

[0107]

[Table 13]

The charge transporting portion of the copolymer of the present invention is such that the repeating unit contains a structure having a charge transporting property and transports a charge opposite to that of the charge transporting material contained in the photosensitive layer. For example, it may be made of any material such as polyvinylcarbazole. However, those containing a fluorenone or triarylamine structure in the repeating unit are preferred in terms of charge mobility, charge injection property, charge life, visible light and infrared light transmittance, chemical stability and the like. In particular, a triarylamine structure represented by the following general formula (IV)
Or those containing at least one of the structures represented by (V) as a repeating unit are preferred.

[0109]

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In the general formula (IV), Ar ¹ and Ar ² are each independently selected from a substituted or unsubstituted aryl group. Specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, a pyrenyl group and the like.
Examples of the substituent include a methyl group, an ethyl group, a methoxy group, and a halogen atom.

X ¹ is selected from a divalent hydrocarbon group having an aromatic ring structure and a hetero atom-containing hydrocarbon group. Specific examples include a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, a methylenediphenyl group, a cyclohexyredenediphenyl group, an oxydiphenyl group, a thiodiphenyl group, and a methyl-substituted, ethyl-substituted, and methoxy-substituted product thereof. Or a halogen-substituted product. In particular, a substituted or unsubstituted biphenylene group is preferred from the viewpoint of charge transportability.

X ² and X ³ are each independently selected from a substituted or unsubstituted arylene group. Specifically, phenylene group, biphenylene group, terphenylene group, naphthylene group and the like, and their methyl-substituted products, ethyl Substitute,
Methoxy-substituted or halogen-substituted products are exemplified.

L ¹ is selected from a divalent hydrocarbon group or a heteroatom-containing hydrocarbon group which may have a branched chain or a ring structure, and is optional as long as it exhibits at least one of the preferable characteristics described above. Those containing a bonding group selected from an ether bond, an ester bond, a carbonate bond, a siloxane bond and the like and having 20 or less carbon atoms are preferred. Specific examples include the following.

[0114]

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In the general formula (V), Ar ³ and Ar ⁴ are each independently selected from a substituted or unsubstituted aryl group. Specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, and a pyrenyl group. Examples of the substituent include an alkyl or alkoxy group having 1 to 12 carbon atoms, a diphenylamino group, and a halogen atom.

L ² is selected from a trivalent hydrocarbon group having an aromatic ring structure or a heteroatom-containing hydrocarbon group, and is arbitrary as long as it exhibits at least one of the preferable characteristics described above. Preferably not more than one. Specific examples include the following.

[0117]

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In the copolymer of the present invention, the compound represented by the above general formula (IV), which is contained as a repeating unit in the charge transporting moiety.
Is shown in Table 6 below. Table 7 below shows specific examples represented by the general formula (V).

[0119]

[Table 14]

[0120]

[Table 15]

[0121]

[Table 16]

The method for synthesizing the copolymer used in the present invention is described in various literatures, for example, 4th edition Experimental Chemistry Lecture 28 Polymer Synthesis (Maruzen, 1992), Macromonomer Chemistry and Industry (IPC, 1990) , Polymer compatibilization and evaluation technology (Technical Information Association, 1992), Polymer New Material One
Any suitable synthetic method that can provide a block copolymer and / or a graft copolymer described in literature such as Point 12 Polymer Alloy (Kyoritsu, 1988) can be used.

For example, a desired block copolymer can be obtained by previously synthesizing a charge transporting polymer and an insulating polymer and reacting and bonding the polymers. Further, when the polymerization mode of the monomer forming the charge transporting portion and the monomer forming the insulating portion are the same and the reactivities of both are greatly different, first, by simply polymerizing a mixture of the monomers, first, After the monomer having higher reactivity is polymerized and the monomer is consumed, the monomer having lower reactivity is polymerized to obtain a desired block copolymer. In addition, a polymer of one monomer is synthesized in advance, and the terminal and / or side chain of the polymer has a polymerization initiating ability of azo, peroxyester, peroxy, dithiocarbamate, alkali metal alcoholate, alkali metal alkyl, or the like. A desired block copolymer or graft copolymer can also be obtained by introducing a group-containing polymerization initiator and polymerizing the other monomer with the polymerization initiator. According to this method, a block copolymer or a graft copolymer comprising a polycondensation or polyaddition polymer and an addition polymerization or ring-opening polymerization polymer can be easily obtained. In addition, using a compound having a plurality of groups having a polymerization initiation ability such as azo, peroxyester, and peroxy in a molecule, first, one monomer is polymerized from a part of the polymerization initiation groups, and then the other polymerization initiation is started. The desired block copolymer can also be obtained by polymerizing the other monomer from the group. Also, a desired block copolymer can be obtained by sequentially polymerizing each monomer by a living polymerization method such as a cation living polymerization method, an anion living polymerization method, or a radical living polymerization method. The living polymerization method can easily control the molecular weight of each block,
In addition, it has the advantage that a polymer having a narrow molecular weight distribution can be obtained. Also, a desired block copolymer can be obtained by sequentially polymerizing each monomer by an immortal polymerization method, an Iniferter method, or the like. Furthermore, a desired macro-copolymer can be obtained by synthesizing a macromonomer in which the other monomer has been introduced into the terminal of the polymer of one monomer in advance, and polymerizing the macromonomer.

The molecular weight of the copolymer (copolymer comprising an insulating portion and a charge transporting portion) of the present invention may be any value, but is 2,000 or more in order to exhibit high molecular properties. It is desired. Preferably 5,000 or more,
More preferably 10,000 or more, further preferably 2
It is more than 0000. The molecular weight is not limited in terms of electrical properties or mechanical properties, and there is no particular limitation on the upper limit of the molecular weight. However, when the film is formed by the wet coating method,
It should be within a range that gives an appropriate solution viscosity. Generally, it is preferable that it is 5,000,000 or less.

The weight ratio between the charge transporting portion and the insulating portion in the copolymer of the present invention is set between 1: 9 and 9: 1. In particular, 2: 8 to 8: 2 is preferable.
3: 7 to 7: 3 are particularly preferred. If the weight ratio of the charge-transporting portion is small, the charge-transporting portion cannot exhibit sufficient charge-transporting properties, causing problems such as an increase in residual potential and a decrease in repetition stability. When the weight ratio of the charge transporting portion is large, the solvent resistance tends to be low.

Antioxidants, light stabilizers, heat stabilizers, etc. are added to the copolymer for the purpose of preventing deterioration of the photoreceptor due to ozone or oxidizing gas generated in the electrophotographic apparatus, or light or heat. can do. As an antioxidant,
Known ones can be used. Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like. Known light stabilizers can be used. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine, and electron-withdrawing compounds or electron-donating compounds that can deactivate the photoexcited state by energy transfer or charge transfer.

Further, various layers can be dispersed and contained in the layer containing the copolymer of the undercoat layer of the photoreceptor of the present invention. For example, insulating particles such as an organic filler and an inorganic filler may be dispersed for the purpose of preventing interference fringes from occurring.

The thickness of the undercoat layer containing the poorly soluble copolymer of the present invention is suitably from 0.01 to 10 μm, preferably from 0.05 to 5 μm. The undercoat layer can be obtained by applying a liquid obtained by dissolving or dispersing a copolymer as a material in a certain solvent.

As the application method, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method can be used.

In the electrophotographic photoreceptor of the present invention, the photosensitive layer contains a charge generation material and a charge transport material. The photosensitive layer may be a single layer having the charge generation material and the charge transport material in one layer, or may be composed of a plurality of layers.

In the case of a single layer, the photosensitive layer is preferably formed by dispersing a charge-generating material in a resin containing a charge-transporting material. In the case of a plurality of layers, the photosensitive layer is a laminated type comprising a charge-generating layer and a charge-transporting layer. You may. When the charge transport layer comprises a plurality of layers, the charge transport layer may be two or more layers.

When the photosensitive layer of the electrophotographic photosensitive member of the present invention is of a single-layer type, it can be prepared by dispersing and applying a charge generating material in a binder resin containing a charge transporting material (for example, 1 and 2). In addition, a material having electron affinity can be included for the purpose of improving photosensitivity, reducing residual potential, and the like. In addition, antioxidants and / or UV absorbers can be included to maintain chemical stability.

In the single-layer type photoreceptor of the present invention, the compounding ratio (weight ratio) of the charge generating material and the binder resin in the photosensitive layer is 1: 1.
A range of １ ： 1: 100 is preferred. More preferably, 1:
It is set in the range of 3 to 1:50. If the compounding ratio of the charge generation material to the binder resin is too large, dark decay increases and mechanical properties deteriorate. On the other hand, if the mixing ratio of the charge generating material to the binder resin is too small, problems such as a decrease in photosensitivity and an increase in residual potential occur.

The thickness of the photosensitive layer in the single-layer type is generally 1 to 100 μm, preferably 5 to 50 μm.
It is set in the range of μm. As a coating method, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used.

As a solvent used for forming the single-layer type photosensitive layer, a solvent having a property of dissolving a binder resin described later is used. Examples of specific solvents include toluene,
Xylene and the like can be mentioned. When the single-layer type photosensitive layer is provided on the undercoat layer, the solvent resistance required for the undercoat layer is one that is resistant to the above-mentioned solvent.

The case where the electrophotographic photoreceptor of the present invention is of a laminate type comprising a charge generation layer and a charge transport layer will be described below. The charge generation layer is formed by depositing a charge generation material by a vacuum deposition method.
Alternatively, it can be produced by coating a material in which a charge generation material is dispersed or dissolved in a binder resin. The charge generation layer may contain a charge transporting low molecular weight compound and / or a charge transporting high molecular weight compound. In addition, an antioxidant and / or an ultraviolet absorber may be included to maintain chemical stability.

In the charge generation layer of the laminated photoreceptor of the present invention, when the layer has a charge generation material and a binder resin, the charge generation material: binder resin composition ratio (weight ratio) is 1
The range of 0: 1 to 1:10 is preferred. More preferably,
The ratio is preferably in the range of 3: 1 to 1: 1. If the compounding ratio of the charge generation material to the binder resin is too large, dark decay increases and mechanical properties deteriorate. On the other hand, if the mixing ratio of the charge generating material to the binder resin is too small, problems such as a decrease in photosensitivity and an increase in residual potential occur.

The thickness of the charge generation layer used in the present invention is generally from 0.05 to 5 μm, and preferably from 0.1 to 2.0 μm. As a coating method, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used. The solvent used at this time preferably has the property of dissolving the binder resin described below. Examples of the solvent used when applying the charge generation layer include xylene and butyl acetate. When the charge generation layer is provided on the undercoat layer, the solvent resistance required for the undercoat layer is one that is resistant to the solvent.

As the charge generating material used for the single-layer type photosensitive layer and the laminated type charge generating layer in the electrophotographic photoreceptor of the present invention, known materials can be used. For example, amorphous selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and alloys, zinc oxide,
Inorganic photoconductive materials such as titanium oxide, a-Si, a-SiC, and organic pigments such as phthalocyanine, squarium, anthantrone, perylene, azo, anthraquinone, pyrene, pyrylium salts, and thiapyrylium salts And dyes can be used, but are not limited thereto. These organic pigments and dyes can be used alone or in combination of two or more.

The phthalocyanine-based compound has an oscillation wavelength of 60 nm of an LED or a laser diode which is currently favorably used as a light source in a digital electrophotographic apparatus.
Since it has excellent photosensitivity at 0 to 850 nm, it is particularly preferable as the charge generation material of the present invention. Specifically, it is a metal-free phthalocyanine, a metal phthalocyanine, and as a central metal of the metal phthalocyanine, Cu, Ni, Zn, Co,
Fe, V, Si, Al, Sn, Ge, Ti, In, G
a, Mg, Pb and the like. In addition, oxides, hydroxides, halides, alkylated compounds, alkoxylated compounds and the like of these central metals can also be used. Specific examples include metal-free phthalocyanine, titanyl phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, vanadyl phthalocyanine, chloroindium phthalocyanine, and dichlorotin phthalocyanine. Further, those having an arbitrary substituent in these phthalocyanine rings can also be used. further,
Those in which arbitrary carbon atoms in these phthalocyanine rings are substituted with nitrogen atoms are also effective. As the form of these phthalocyanine compounds, it is possible to use amorphous or all polymorphic forms.

Among these phthalocyanine compounds,
Titanyl phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, and dichlorotin phthalocyanine have particularly excellent photosensitivity and are particularly preferred as charge generation materials.

Examples of the binder resin used for the single-layer and multilayer charge-generating layers in the electrophotographic photoreceptor of the present invention include polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal resin, polycarbonate resin, and polyester resin. , Acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin,
Examples include, but are not limited to, vinyl chloride-vinyl acetate copolymers, silicone resins, phenolic resins, poly-N-vinyl carbazole resins, and the like. These binder resins can be block, random or alternating copolymers. These binder resins can be used alone or in combination of two or more.

As the charge transporting layer in the photoreceptor of the present invention, a known charge transporting layer used as a charge transporting layer in a conventional laminated photoreceptor can be used. For example, benzidine compounds, amine compounds, hydrazone compounds,
Stilbene compounds, hole transporting low molecular weight compounds such as carbazole compounds or fluorenone compounds, malononitrile compounds, electron transporting low molecular weight compounds such as diphenoquinone compounds, alone or as a mixture of two or more, polycarbonate, A solid solution film in which molecules are uniformly dispersed in an insulating resin such as polyarylate, polyester, polysulfone, and polymethyl methacrylate, or a polymer compound having a charge transporting ability by itself can be used. Further, an inorganic substance having a charge transporting ability, such as selenium, amorphous silicon, or amorphous silicon carbide, can also be used. Examples of the charge transporting polymer compound include a polymer compound having a charge transporting group such as polyvinylcarbazole in a side chain, and a group having a charge transporting function as disclosed in JP-A-5-232727. And a polysilane having a main chain of

The thickness of the charge transport layer used in the present invention is from 1 to 1
00 μm, preferably 5 to 50 μm. As a coating method, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used. The solvent used for coating preferably has the property of dissolving the above-mentioned hole or electron transporting low molecular weight compound and insulating resin. Examples of the solvent used when applying the charge transport layer include monochlorobenzene, p-
Xylene, toluene and the like can be mentioned. When the charge transport layer is provided on the undercoat layer, the solvent resistance required for the undercoat layer is one that is resistant to the solvent. In addition, when the material of the charge transport layer is a material that can be formed in a vapor phase, it can be directly formed by a vacuum deposition method or the like.

A surface protective layer may be further provided on a single-layer type photosensitive layer or a photosensitive layer comprising a charge generation layer and a charge transport layer. This surface protective layer protects the photosensitive layer from chemical stress such as ozone, oxidizing gas or ultraviolet light generated from the charging member, or mechanical stress caused by contact with a developer, paper or a cleaning member. Is effective for improving the substantial life of the photosensitive layer. In particular, when the thin charge generating layer is the uppermost layer, the effect of providing the surface protective layer is particularly remarkable.

The film thickness of the surface protective layer is suitably from 0.5 to 20 μm, and preferably from 1 to 10 μm. When a surface protective layer is provided, a blocking layer for preventing leakage of electric charge from the protective layer to the photosensitive layer can be provided between the photosensitive layer and the protective layer, if necessary. As the blocking layer, a known layer can be used.

In the electrophotographic photosensitive member of the present invention, ozone or oxidizing gas generated in the electrophotographic apparatus, or
An antioxidant, a light stabilizer, a heat stabilizer and the like can be added to each layer or the uppermost layer for the purpose of preventing the photoconductor from being deteriorated by light and heat. As the antioxidant, known compounds can be used, and examples thereof include hindered phenol, hindered amine, paraphenylenediamine, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. . As the light stabilizer, known ones can be used, for example, derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine, and electron withdrawing properties that can deactivate the photoexcited state by energy transfer or charge transfer. And a compound or an electron donating compound.

Furthermore, reduction of surface wear, improvement of transferability,
Insulating particles such as a fluororesin may be dispersed in the outermost surface layer for the purpose of improving the cleaning property and the like. As a method for forming each layer, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used.

When two charge transport layers are provided in the electrophotographic photoreceptor of the present invention (FIGS. 5 and 6), the thickness of the first charge transport layer is suitably from 0.1 to 50 μm, and preferably from 0.1 to 50 μm. 0.2 to 15 μm, more preferably 0.5 to 10
It is set in the range of μm. The electrophotographic photoreceptor of the present invention is
If desired, a diffuse reflection layer or the like can be included between the undercoat layer and the conductive substrate.

As the electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention, any apparatus may be used as long as it uses an electrophotographic method. For example, analog exposure type electrophotographic copying machine, laser exposure type digital electrophotographic copying machine,
Electrophotographic facsimile, laser beam printer,
Examples include an LED printer and a liquid crystal shutter printer. Cleaning means together with the electrophotographic photosensitive member,
The device unit may be combined with at least one of a charging unit and a developing unit.

[0151]

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the following examples, and those skilled in the art can modify the following examples based on known knowledge of electrophotographic technology.

<Synthesis Example I-1> Synthesis of Reactive Polymerization Initiator 4,4'-Azobis (4-cyanovaleric chloride) 220 ml of thionyl chloride was cooled with ice, and 4,4'-azobis (4-
100 g of cyanovaleric acid) were gradually added. The mixture was heated at 30 ° C. for 6 hours, and excess thionyl chloride was distilled off under reduced pressure. The residue was recrystallized from chloroform to give 4,4'-azobis (4
42 g of (cyanovaleric acid chloride) crystals were obtained.

<Synthesis Example I-2> 1 g of polyvinyl alcohol (manufactured by Wako Pure Chemical Industries, polymerization degree: about 500), 7.1 g of 2,7-dinitrofluorenone-4-carboxylic acid, and pyridine 7.
9 ml was dissolved in 50 ml of N, N-dimethylacetamide. To this solution, a solution prepared by dissolving 5.7 g of 2,4,6-trinitrochlorobenzene separately prepared in 100 ml of N, N-dimethylacetamide was slowly added dropwise. After the completion of the dropwise addition, the mixture was heated to 80 ° C., and the reaction was continued for 24 hours. After completion of the reaction, 50 ml of acetone was added, and the precipitated polymer was separated by filtration and sufficiently washed with acetone. The obtained polymer was dissolved in 50 ml of N, N-dimethylacetamide. This polymer solution was slowly dropped into acetone while stirring, and a reprecipitation treatment was performed. The precipitated polymer was separated by filtration, sufficiently washed with acetone, and dried under reduced pressure to obtain 3.5 g of a prepolymer. The weight average molecular weight of the obtained prepolymer was 6.3 × 10 ⁴ .

Dissolve 3.0 g of the above polymer and 0.035 g of triethylamine in 20 ml of tetrahydrofuran,
Cooled to below 0 ° C. Here, it was obtained in Synthesis Example I-1.
0.39 g of 4,4'-azobis (4-cyanovaleric chloride)
Was suspended in 1.4 ml of tetrahydrofuran. After reacting at room temperature for 1 hour, the reaction was carried out at 30 ° C. for 6 hours. This reaction solution was dropped into acetone, stirred for 1 hour, and filtered off. This reprecipitation operation was repeated twice more. The remaining compound was dried to obtain 2.5 g of a polymer having an azo type polymerization initiator at a hydroxyl group terminal.

2 g of the above polymerization initiator-containing polymer, 2 g of methyl methacrylate, and 0.67 g of methacrylic acid were dissolved in 40 ml of tetrahydrofuran, and the solution was replaced with nitrogen.
Heat at 95 ° C. for 95 hours. This solution was added dropwise to methanol, stirred for 1 hour, and filtered off. The obtained solid was sufficiently washed with a mixed solution of tetrahydrofuran / acetone / methanol to obtain 2.2 g of a block copolymer represented by the following structural formula (I-1). This copolymer had a charge transporting block having a fluorenone structure and an insulating block having a carboxylic acid group as a hardly soluble group. The weight average molecular weight of the obtained copolymer is 11 × 10 ⁴ ,
From the integral ratio of the peaks corresponding to the protons specific to both blocks in the ¹ H-NMR spectrum of the obtained block copolymer, the weight composition ratio of the charge transporting block and the insulating block was calculated to be about 3: 2. . Similarly, the weight composition ratio between the hardly soluble portion and the soluble portion in the insulating block was calculated to be about 3: 7.

[0156]

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<Synthesis Example I-3> N, N'-bis (p, m-dimethylphenyl) -N, N'-bis [p- (2-methoxycarbonylethyl) phenyl]-[3,3'- Dimethyl-1,1'-biphenyl] -4,
100 g of 4'-diamine, 200 g of ethylene glycol and 5 g of tetrabutoxy titanium were heated and refluxed for 3 hours under a nitrogen stream. After confirming that N, N'-diphenyl-N, N'-bis [p- (2-methoxycarbonylethyl) phenyl]-[1,1'-biphenyl] -4,4'-diamine has been consumed, ,
The pressure was reduced to 0.5 mmHg, the mixture was heated to 230 ° C. while distilling off ethylene glycol, and the reaction was continued for another 5 hours. Thereafter, the mixture was cooled to room temperature, methylene chloride was added to dissolve the insoluble matter, and the precipitate was reprecipitated from acetone to obtain 90 g of a prepolymer having hydroxy groups at both ends. The weight average molecular weight of the obtained prepolymer was 7.4 × 10 ⁴ .

The above polymer (43 g) and triethylamine (0.5 g) were dissolved in toluene (120 ml) and cooled to 0 ° C. or lower. Here, 5.6 g of 4,4′-azobis (4-cyanovaleric acid chloride) obtained in Synthesis Example I-1 was added to toluene 20
The liquid suspended in ml was dropped. After reacting at room temperature for 1 hour, the reaction was carried out at 30 ° C. for 6 hours. The solvent was distilled off from this, and it was dissolved by adding tetrahydrofuran, added dropwise to methanol, stirred for 1 hour, and filtered. This reprecipitation operation was repeated twice more. The remaining compound was dried to obtain 41 g of a polymer having an azo-type polymerization initiator at a terminal.

6 g of the polymerization initiator-containing polymer, 6 g of methyl methacrylate, and 2 g of maleic anhydride were added to toluene 1
After dissolving in 20 ml and purging with nitrogen, the mixture was heated at 65 ° C. for 95 hours. This solution was added dropwise to methanol, stirred for 1 hour, and filtered off. The obtained solid was sufficiently washed with a mixed solution of tetrahydrofuran / acetone / methanol to obtain 7 g of a block copolymer represented by the following structural formula (I-2). As apparent from the structural formula, this copolymer had a charge transporting block containing a triarylamine structure and an insulating block having a maleic anhydride skeleton as a hardly soluble group. The weight average molecular weight of the resulting copolymer was 10 × 10 ^4, the resulting block copolymer ¹ H-
From the integral ratio of peaks corresponding to protons specific to both blocks in the NMR spectrum, the weight composition ratio of the charge transporting block and the insulating block was calculated to be about 3: 2. Similarly, the weight composition ratio between the hardly soluble portion and the soluble portion in the insulating block was calculated to be about 3: 7.

[0160]

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<Synthesis Example I-4> 2.4 g of the polymerization initiator-containing polymer obtained in Synthesis Example I-3 and 4.8 g of 1,1,2,2,2-pentafluoroethyl acrylate were dissolved in 25 ml of tetrahydrofuran. After purging with nitrogen, the mixture was heated at 70 ° C. for 72 hours. This solution was added dropwise to methanol, stirred for 1 hour, and filtered off. The obtained solid was sufficiently washed with a mixed solution of tetrahydrofuran / acetone / methanol, and a block copolymer 4.6 represented by the following structural formula (I-3) was obtained.
g was obtained. This copolymer, as can be seen from the structural formula,
It had a charge transporting block containing a triarylamine structure and an insulating block having a fluorine atom as a hardly soluble group. The weight average molecular weight of the obtained copolymer is 9.
4 × 10 ⁴ , and ¹ H—N of the obtained block copolymer
From the integral ratio of the peaks corresponding to the protons specific to both blocks in the MR spectrum, the weight composition ratio between the charge transporting block and the poorly soluble insulating block was calculated to be approximately 1: 1.

[0162]

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<Comparative Synthesis Example I-1> The following structural formula (I) was prepared in the same manner as in Synthesis Example I-3 except that 1,1,2,2,2-pentafluoroethyl acrylate was replaced with methyl methacrylate.
-4) was synthesized. This copolymer had a charge transporting block containing a triarylamine structure and an insulating block having a soluble group. The weight average molecular weight of the obtained block copolymer is 10
× 10 ⁴ , and ¹ H-NM of the obtained block copolymer
From the integral ratio of the peaks corresponding to the protons specific to both blocks in the R spectrum, the weight composition ratio of the charge transporting block and the insulating block was calculated to be approximately 1: 1.

[0164]

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(Example I-1) 10 parts by weight of the block copolymer obtained in Synthesis Example I-4 was mixed with tetrahydrofuran 90
The solution dissolved in parts by weight was applied on an aluminum plate by a dip coating method, and then dried by heating at 135 ° C. for 60 minutes to form a 0.8 μm undercoat layer. Next, polycarbonate Z resin (Iupilon Z-400,
8 parts by weight of Mitsubishi Gas Chemical Co., Ltd.) and the following structural formula (I-
2 parts by weight of chlorogallium phthalocyanine was added to a solution prepared by dissolving 5 parts by weight of the low-molecular-weight charge-transporting substance shown in 5) in 85 parts of toluene in advance, and the mixture was dispersed with stainless beads by a ball mill for 48 hours. This coating solution was applied on the undercoat layer by a dip coating method, and dried by heating at 135 ° C. for 60 minutes to form a photosensitive layer having a thickness of 20 μm, thereby producing an electrophotographic photosensitive member having a structure shown in FIG. did.

[0166]

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Even after the formation of the photosensitive layer, the undercoat layer did not have cracks or the like, and the thickness of the photosensitive layer was uniform and excellent. The electrophotographic photoreceptor thus obtained was subjected to normal temperature and normal humidity (20 ° C., 40% RH) using an electrostatic copying paper tester (Electrostatic Analyzer EPA-8100, manufactured by Kawaguchi Electric Works). The electrophotographic properties were evaluated under the environment described above. After adjusting the corona discharge voltage and charging the photoreceptor surface to -750 V, the photoreceptor was passed through an interference filter.
Halogen lamp light monochromatized to 50 nm was adjusted to have a light intensity of ² mW / m ² on the surface of the photoreceptor. This light was irradiated for 7 seconds, and the half-decrease exposure amount E was obtained from the photoinduced potential decay curve.
Asked for ₅₀ . The potential 7 seconds after the start of exposure was defined as the residual potential. E ₅₀ is 6.7mJ / m ^2, the residual potential was -60 V.

Example I-2 10 parts by weight of the block copolymer obtained in Synthesis Example I-3 was mixed with tetrahydrofuran 90
The solution dissolved in parts by weight was applied on an aluminum plate by a dip coating method, and then dried by heating at 135 ° C. for 60 minutes to form a 0.8 μm undercoat layer.

Next, 4 parts by weight of chlorogallium phthalocyanine microcrystals were mixed with 2 parts by weight of a vinyl chloride-vinyl acetate copolymer (trade name: UCAR Solution Vinyl Resin VMCH, manufactured by Union Carbide), 67 parts by weight of xylene, and acetic acid After mixing with 33 parts by weight of butyl and dispersing the mixture with glass beads having a diameter of 1 mm using a sand grinder for 2 hours, the obtained coating solution was applied onto the undercoat layer by a dip coating method. Thereafter, the resultant was dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

Further, 20 parts by weight of the low-molecular charge transporting material represented by the structural formula (I-5) was added to monochlorobenzene 8
It was dissolved in 0 parts by weight and applied on the charge generation layer by a dip coating method. Thereafter, the resultant was dried by heating at 135 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm. Thus, an electrophotographic photosensitive member having a structure shown in FIG. 3 was produced.

After the formation of the charge generation layer, the undercoat layer was free from cracks and the like, and the thickness of the charge generation layer was uniform and excellent. The electrophotographic photosensitive member thus obtained was evaluated in the same manner as in Example I-1, except that the charging polarity was made positive. E ₅₀ is 4.8mJ / m ^2, the residual potential was 40V.

Example I-3 10 parts by weight of the block copolymer obtained in Synthesis Example I-2 was mixed with tetrahydrofuran 90
The solution dissolved in parts by weight was applied on an aluminum plate by a dip coating method, and then dried by heating at 135 ° C. for 60 minutes to form a 0.8 μm undercoat layer.

Next, 4 parts by weight of chlorogallium phthalocyanine microcrystals were mixed with 2 parts by weight of a vinyl chloride-vinyl acetate copolymer (trade name: UCAR Solution Vinyl Resin VMCH, manufactured by Union Carbide), 67 parts by weight of xylene, and acetic acid The mixture was mixed with 33 parts by weight of butyl and dispersed by treating with glass beads having a diameter of 1 mm by a sand grinder for 2 hours. Thereafter, the obtained coating solution was applied on the undercoat layer by a dip coating method, and dried by heating at 100 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer.

Further, 20 parts by weight of a polymer charge transporting material having a molecular weight of 80,000 and comprising a repeating unit represented by the following structural formula (I-6) was dissolved in 80 parts by weight of monochlorobenzene. This solution was applied on the charge generation layer by dip coating, and dried by heating at 135 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm. The electrophotographic photoreceptor having the structure shown in FIG. Was prepared.

[0175]

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Even after the formation of the charge generation layer, the undercoat layer did not generate cracks and the like, and the thickness of the charge generation layer was uniform and excellent. The electrophotographic photoreceptor thus obtained was evaluated in the same manner as in Example I-1. E ₅₀ 4.
4 mJ / m ² and the residual potential was −20 V.

(Comparative Example I-1) 20 parts by weight of a zirconium alkoxide compound (trade name: Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and 2 parts by weight of γ-aminopropyltriethoxysilane (trade name: A1100, manufactured by Nippon Unicar Co., Ltd.) And a solution consisting of 1.5 parts by weight of a polyvinyl butyral resin (S-LEC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 70 parts by weight of n-butanol were applied on an aluminum plate by a dip coating method, and then heated at 170 ° C. The film was cured by heating for 10 minutes to form an undercoat layer having a thickness of 1.0 μm. Next, a charge generation layer and a charge transport layer were formed in the same manner as in Example I-3, and an electrophotographic photoconductor was manufactured. The electrophotographic photoreceptor thus obtained was evaluated in the same manner as in Example I-3. E ₅₀ is 4.9 mJ / m ² , and residual potential is −60.
V.

Comparative Example I-2 Example I-3 was repeated, except that the block copolymer obtained in Comparative Synthesis Example I-1 was used instead of the block copolymer obtained in Synthesis Example I-2. An electrophotographic photoreceptor was prepared in the same manner as described above. The charge generation layer was a film having a non-uniform thickness. This is probably because the undercoat layer was not hardly dissolved, and swelling and dissolution occurred during application of the charge generation layer.

(Example I-4) An electrophotographic photosensitive member was produced in the same manner as in Example I-3, except that an aluminum drum having a roughened surface was used instead of the aluminum substrate.
The printer was mounted on a laser printer (Laser Press 4105, manufactured by Fuji Xerox Co., Ltd.) and a printing test was performed. At this time, an ND filter was provided in the optical path of the laser beam in order to obtain an optimal exposure amount. FIG. 7 shows a schematic configuration diagram of this laser printer. A pre-exposure light source (red LED) 11, a charging scorotron 12, an exposure laser optical system 13, a developing device 14, a transfer corotron 15, and a cleaning blade 16 are sequentially arranged around the photosensitive drum 10 in the order of the process. I have. The exposure laser optical system 13 includes an exposure laser diode having an oscillation wavelength of 780 nm, and emits light based on a digitally processed image signal. The emitted laser light 13 is configured to expose the photoreceptor while being scanned by a polygon mirror, a plurality of lenses, and a mirror. Reference numeral 17 denotes a sheet.

(Comparative Example I-3) An electrophotographic photosensitive member was manufactured in the same manner as in Comparative Example I-1, except that an aluminum drum having a roughened surface was used instead of the aluminum substrate.
A printing test was performed in the same manner as in Example I-4. Example I-4
And the quality of the printing obtained in Comparative Example I-3,
Example I-4 was superior in print quality in terms of contrast reproducibility and the like, and the change in print quality after a 1,000-sheet print test was small.

<Synthesis Example II-1> Synthesis of reactive polymerization initiator 4,4'-azobis (4-cyanovaleric chloride) In the same manner as in Synthesis Example I-1, 4,4'-azobis (4-cyano Valeric acid chloride) was synthesized to obtain 42 g of the compound.

<Synthesis Example II-2> As in Synthesis Example I-2, 3.5 g of a prepolymer having a weight average molecular weight of 6.3 × 10 ⁴ was obtained as an intermediate. In addition, using this prepolymer, 2.5 g of a polymer having an azo-type polymerization initiator at a hydroxyl group terminal was obtained in the same manner as in Synthesis Example I-2.

The above polymerization initiator-containing polymer (2 g), methyl methacrylate (2 g), and 2-hydroxyethyl methacrylate (0.67 g) were dissolved in tetrahydrofuran (40 ml).
After purging with nitrogen, the mixture was heated at 65 ° C. for 95 hours. This solution was added dropwise to methanol, stirred for 1 hour, and filtered off.
The obtained solid was sufficiently washed with ethanol to obtain 2.4 g of a block copolymer represented by the following structural formula (II-3). As can be seen from the structural formula (II-3), this copolymer had a charge transporting block containing a fluorenone structure and an insulating block having a hydroxy group as a crosslinkable functional group. The weight average molecular weight of the obtained copolymer was 10 × 10 ⁴ , and the charge transporting block was determined from the integral ratio of the peaks corresponding to the protons specific to both blocks in the ¹ H-NMR spectrum of the obtained block copolymer. The weight composition ratio between the and the insulating block was calculated to be about 3: 2. Similarly, the weight composition ratio of the crosslinked portion and the non-crosslinked portion in the insulating block was calculated to be about 3: 7.

[0184]

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<Synthesis Example II-3> N, N'-bis (p, m-dimethylphenyl) -N, N'-bis [p- (2-methoxycarbonylethyl) phenyl]-[3,3'- Dimethyl-1,1'-biphenyl] -4,
100 g of 4'-diamine, 200 g of ethylene glycol and 5 g of tetrabutoxy titanium were heated and refluxed for 3 hours under a nitrogen stream. After confirming that N, N'-diphenyl-N, N'-bis [p- (2-methoxycarbonylethyl) phenyl]-[1,1'-biphenyl] -4,4'-diamine has been consumed, ,
The pressure was reduced to 0.5 mmHg, the mixture was heated to 230 ° C. while distilling off ethylene glycol, and the reaction was continued for another 5 hours. Thereafter, the mixture was cooled to room temperature, methylene chloride was added to dissolve the insoluble matter, and the precipitate was reprecipitated from acetone to obtain 90 g of a prepolymer having hydroxy groups at both ends. The weight average molecular weight of the obtained prepolymer was 7.4 × 10 ⁴ .

43 g of the above polymer and 0.5 g of triethylamine were dissolved in 120 ml of toluene, and cooled to 0 ° C. or lower. Here, 5.6 g of 4,4′-azobis (4-cyanovaleric chloride) obtained in Synthesis Example II-1 was added to 20 m of toluene.
l was added dropwise. After reacting at room temperature for 1 hour, the reaction was carried out at 30 ° C. for 6 hours. The solvent is distilled off from here,
Tetrahydrofuran was added to dissolve the solution, dropped into methanol, stirred for 1 hour, and then filtered. This reprecipitation operation was repeated twice more. The remaining compound was dried to obtain 41 g of a polymer having an azo-type polymerization initiator at a terminal.

6 g of the polymerization initiator-containing polymer, 6 g of methyl methacrylate, and 2 g of 2-hydroxyethyl methacrylate were dissolved in 120 ml of toluene, and the mixture was purged with nitrogen and heated at 65 ° C. for 95 hours. This solution was added dropwise to methanol, stirred for 1 hour, and filtered off. The obtained solid was sufficiently washed with methanol to obtain 6 g of a block copolymer represented by the following structural formula (II-4). This copolymer had a charge transporting block containing a triarylamine structure and an insulating block having a hydroxy group as a crosslinkable functional group, as shown in Structural Formula (II-4). The weight average molecular weight of the obtained copolymer is 12 × 1
0 is ^4, from the area ratio of the peaks corresponding to the two blocks unique proton ¹ H-NMR spectrum of the obtained block copolymer, the weight composition ratio of the charge transporting blocks insulating block is about 3: Calculated as 2. Similarly, the weight composition ratio between the crosslinked portion and the non-crosslinked portion in the insulating block was calculated to be about 3: 7.

[0188]

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<Synthesis Example II-4> N, N'-bis (p, m-dimethylphenyl) -N, N'-bis [p- (2-methoxycarbonylethyl) phenyl]-[3,3'- Dimethyl-1,1'-biphenyl] -4,
4'-Diamine is converted to N, N-bis (p, m-dimethylphenyl) -N-
[p- (m, m'-Bismethoxycarbonylethyl) phenyl] amine was replaced with 2-methoxyethyl methacrylate by trimethoxysilylpropyl methacrylate, and was treated in the same manner as in Synthesis Example II-3. A block copolymer composed of a charge transporting block having a triarylamine structure and an insulating block having an alkoxysilyl group as a crosslinkable functional group represented by -5) was synthesized. The weight average molecular weight of the obtained copolymer was 11 × 10 ⁴
From the integration ratio of the peaks corresponding to the protons specific to both blocks in the ¹ H-NMR spectrum of the obtained block copolymer, the weight composition ratio of the charge transporting block and the insulating block was approximately 3: 2. calculated. The weight composition ratio between the crosslinked portion and the non-crosslinked portion in the insulating block was calculated to be about 3: 7.

[0190]

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<Synthesis Example II-5> Synthesis was performed in the same manner as in Synthesis Example II-3 except that 2-hydroxyethyl methacrylate of Synthesis Example II-3 was not added. The weight average molecular weight of the obtained block copolymer was 11 × 10 ⁴ , and the charge transport property was determined from the integral ratio of peaks corresponding to protons specific to both blocks in the ¹ H-NMR spectrum of the obtained block copolymer. The weight composition ratio between the block and the insulating block was calculated to be approximately 2: 1.

Example II-1 5 parts by weight of the block copolymer obtained in Synthesis Example II-4 was previously dissolved in 95 parts of toluene, and 0.1 part by weight of acetic acid was added. It was applied on top and cured by heating at 135 ° C. for 60 minutes to form a 0.8 μm undercoat layer. Next, polycarbonate Z resin (Iupilon Z-400,
8 parts by weight of Mitsubishi Gas Chemical Co., Ltd. and structural formula (II-6)
2 parts by weight of chlorogallium phthalocyanine were added to a solution of 5 parts by weight of a low-molecular charge transporting material previously shown in 85 parts of toluene, and the mixture was dispersed with stainless beads by a ball mill for 48 hours. This coating solution was applied on the undercoat layer by a dip coating method,
Heat drying for 0 minutes to form a photosensitive layer having a thickness of 20 μm,
An electrophotographic photosensitive member having the structure shown in FIG. 1 was produced.

[0193]

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Even after the formation of the photosensitive layer, the undercoat layer did not have cracks or the like, and the photosensitive layer was a uniform and good film. The electrophotographic photoreceptor thus obtained was subjected to normal temperature and normal humidity (20 ° C., 40% RH) using an electrostatic copying paper tester (Electrostatic Analyzer EPA-8100, manufactured by Kawaguchi Electric Works). The electrophotographic properties were evaluated under the environment described above. After adjusting the corona discharge voltage and charging the photoreceptor surface to -750 V, the photoreceptor was passed through an interference filter.
Halogen lamp light monochromatized to 50 nm was adjusted to have a light intensity of ² mW / m ² on the surface of the photoreceptor. This light was irradiated for 7 seconds, and the half-exposure amount E
Asked for ₅₀ . The potential 7 seconds after the start of exposure was defined as the residual potential. E ₅₀ is 6.8mJ / m ^2, the residual potential is -7
It was 0V.

Example II-2 10 parts by weight of the block copolymer obtained in Synthesis Example II-3 and 1 part by weight of a trivalent isocyanate compound represented by the structural formula (II-1) as a crosslinking agent were used. A solution dissolved in 90 parts by weight of cyclohexanone was applied on an aluminum plate by a dip coating method, and then cured by heating at 150 ° C. for 60 minutes.
An undercoat layer of 0.8 μm was formed.

Next, 4 parts by weight of chlorogallium phthalocyanine microcrystals were mixed with 2 parts by weight of a vinyl chloride-vinyl acetate copolymer (trade name: UCAR Solution Vinyl Resin VMCH, manufactured by Union Carbide), 67 parts by weight of xylene, and acetic acid The mixture was mixed with 33 parts by weight of butyl and dispersed by treating with glass beads having a diameter of 1 mm in a sand grinder for 2 hours. Thereafter, the obtained coating solution was applied on the undercoat layer by a dip coating method, and dried by heating at 100 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer.

Further, 20 parts by weight of the low molecular charge transporting compound represented by the structural formula (II-6) was added to monochlorobenzene 80
It was dissolved in parts by weight and applied on the charge generation layer by dip coating. Thereafter, the resultant was dried by heating at 135 ° C. for 1 hour to form a charge transporting layer having a thickness of 20 μm. Thus, an electrophotographic photosensitive member having a structure shown in FIG. 3 was produced.

After the formation of the charge generation layer, the undercoat layer was free from cracks and the like, and the thickness of the charge generation layer was uniform and excellent. The electrophotographic photosensitive member thus obtained was evaluated in the same manner as in Example II-1, except that the charging polarity was made positive. E ₅₀ is 5.7mJ / m ^2, the residual potential was 60V.

Example II-3 10 parts by weight of the block copolymer obtained in Synthesis Example II-2 and 1 part by weight of a trivalent isocyanate compound represented by the structural formula (II-1) as a crosslinking agent were used. A solution dissolved in 90 parts by weight of cyclohexanone was applied on an aluminum plate by a dip coating method, and then cured by heating at 150 ° C. for 60 minutes.
An undercoat layer of 0.8 μm was formed.

Next, 4 parts by weight of chlorogallium phthalocyanine microcrystals were mixed with 2 parts by weight of a vinyl chloride-vinyl acetate copolymer (trade name: UCAR Solution Vinyl Resin VMCH, manufactured by Union Carbide), 67 parts by weight of xylene, and acetic acid The mixture was mixed with 33 parts by weight of butyl and dispersed by treating with glass beads having a diameter of 1 mm in a sand grinder for 2 hours. Thereafter, the obtained coating solution was applied on the undercoat layer by a dip coating method, and dried by heating at 100 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer.

Further, 20 parts by weight of a polymer charge transporting material having a molecular weight of 80,000 and comprising a repeating unit represented by the following structural formula (II-7) was dissolved in 80 parts by weight of monochlorobenzene. This solution was applied on the charge generation layer by dip coating, and dried by heating at 135 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm. Produced.

[0202]

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Even after the formation of the charge generation layer, the undercoat layer did not generate cracks and the like, and the thickness of the charge generation layer was uniform and excellent. The electrophotographic photoreceptor thus obtained was evaluated in the same manner as in Example II-1. E ₅₀ is 4.5mJ / m ^2, the residual potential was -30 V.

(Comparative Example II-1) 20 parts by weight of a zirconium alkoxide compound (trade name: Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and γ-aminopropyltriethoxysilane (trade name: A1100, manufactured by Nippon Unicar) 2
Parts by weight and polyvinyl butyral resin (S-LEC BM-S,
A solution consisting of 1.5 parts by weight of Sekisui Chemical Co., Ltd.) and 70 parts by weight of n-butanol was applied on an aluminum plate by a dip coating method, and then heated and dried at 170 ° C. for 10 minutes to form a film having a thickness of 1.0 μm. An undercoat layer was formed. Next, a charge generation layer and a charge transport layer were formed in the same manner as in Example II-3, and an electrophotographic photoconductor was manufactured. The electrophotographic photoreceptor thus obtained was evaluated in the same manner as in Example II-3. E ₅₀ is 4.9 mJ / m ² , residual potential is −6
It was 0V.

(Comparative Example II-2) An electrophotographic photosensitive member was prepared in the same manner as in Example II-3, except that no isocyanate compound was added. The charge generation layer was a film having a non-uniform thickness. It is considered that the molecular structure was not three-dimensionally formed by crosslinking of the undercoat layer due to the absence of the isocyanate compound, and swelling and dissolution occurred when the charge generation layer was applied.

(Example II-4) 15 parts by weight of the block copolymer obtained in Synthesis Example II-5 and 1 part by weight of a peroxide, t-butyl peroxyisopropyl monocarbonate, as a crosslinking agent were added to 84 parts by weight of toluene. The solution dissolved in the part was applied on an aluminum plate by a dip coating method, and then cured by heating at 150 ° C. for 30 minutes to form a film having a thickness of 1.0 μm.
m was formed. Next, a charge generation layer and a charge transport layer were formed in the same manner as in Example II-2, to produce a photoconductor for electrophotography. The electrophotographic photoreceptor thus obtained was evaluated in the same manner as in Example II-2. E ₅₀ 5.8
mJ / m ² , and the residual potential was 70 V.

(Example II-5) An electrophotographic photosensitive member was produced in the same manner as in Example II-3 except that an aluminum drum having a roughened surface was used instead of the aluminum substrate, and a laser printer (Laser Press) was used. 4105, manufactured by Fuji Xerox Co., Ltd.). At this time, an ND filter was provided in the optical path of the laser beam in order to obtain an optimal exposure amount. FIG. 7 shows a schematic configuration diagram of this laser printer.

Around the photosensitive drum 10, a pre-exposure light source (red LED) 11, a charging scorotron 12, an exposure laser optical system 13, a developing unit 14, and a transfer corotron 1
5 and the cleaning blade 16 are sequentially arranged in the order of the process. The exposure laser optical system 13 includes an exposure laser diode having an oscillation wavelength of 780 nm, and emits light based on a digitally processed image signal.
The emitted laser light 13 is configured to expose the surface of the photoconductor while being scanned by a polygon mirror and a plurality of lenses and mirrors. Reference numeral 17 denotes a sheet.

(Comparative Example II-3) An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example II-1, except that an aluminum drum having a roughened surface was used instead of the aluminum substrate. A printing test was performed in the same manner as in No. 5. When the quality of the prints obtained in Example II-5 and Comparative Example II-3 was compared, the print quality of Example II-5 was superior in terms of contrast reproducibility, etc. Subsequent changes in print quality were small.

[0210]

According to the present invention, it is possible to provide an electrophotographic photoreceptor which has excellent electrical characteristics, does not cause any problem during lamination film formation, and has a high degree of freedom in designing materials for lamination film formation. Also,
An electrophotographic apparatus using the electrophotographic photosensitive member can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating an example of the structure of a single-layer type photoconductor.

FIG. 2 is a schematic cross-sectional view of a photosensitive member having a protective layer on the photosensitive layer of the single-layer photosensitive member of FIG.

FIG. 3 is a schematic cross-sectional view illustrating an example of the structure of a stacked photoconductor.

FIG. 4 is a schematic cross-sectional view of a photoreceptor having a protective layer on a photosensitive layer of the laminated photoreceptor of FIG.

FIG. 5 is a schematic cross-sectional view illustrating an example of a photoconductor in which two charge transport layers are present among the photosensitive layers of the stacked photoconductor.

6 is a schematic cross-sectional view of a photoconductor having a protective layer on the photoconductor layer of the laminated photoconductor of FIG. 5;

FIG. 7 is a schematic configuration diagram of a laser printer using the photoconductor of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 conductive substrate, 2 undercoat layer, 3 photosensitive layer, 4 charge generation layer, 5 charge transport layer, 6 first charge transport layer, 7
Second charge transport layer, 8 surface protective layer, 10 photoreceptor, 1
1 Pre-exposure light source (red LED), 12 Scorotron for charging, 13 Laser light, 14 Developing device, 15 Corotron for transfer, 16 Cleaning blade, 17 Paper.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08F 222/40 C08F 222/40 293/00 293/00 C08J 3/24 CEY C08J 3/24 CEYZ (72) Inventor Masahiro Iwasaki 1600 Takematsu, Minami Ashigara, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Taketoshi Hoshizaki 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. Address F-term in Fuji Xerox Co., Ltd. (reference) 2H068 AA43 AA48 BB02 BB20 BB44 BB57 BB61 BB62 EA12 FB02 FB05 4F070 AA12 AA17 AA18 AA23 AA25 AA29 AA33 AA34 AA35 AA37 AC35 AC40 GA45 AC53 AC06 GA03 GB09 GC09 4J026 HA06 HA11 HA17 HA46 HB05 HB06 HB09 HB10 HB11 HB12 HB20 HB22 HB32 HE01 HE02 4J10 0 AA15Q AA17Q AA19Q AA21Q AB00Q AB02Q AB03Q AB04Q AB07Q AB07R AC21P AC22P AD07P AE01Q AF10Q AJ01P AJ02P AK31P AK32P AK33P AL03Q AL04Q AL05Q AL08P AL08Q AL08R AL19Q AL24Q AM01P AM02P AM03P AM15P AM17P AM42P AM43P AM45P AM47P AM48P AS06P BA03P BA03R BA16R BA29R BA40P BA40R BA42R BA52R BA58R BA75R BB01P BB01R BB07P BB12P BB17P BB18P BC02Q BC04Q BC26Q BC43P BC43Q BC48Q BC49Q BC54R CA04 CA05 CA31 DA01 HA53 HC04 HC12 HC28 HC36 HC43 HC51 HC54 HC78 HC80 JA43

Claims (10)

[Claims] 1. An electrophotographic photoreceptor having an undercoat layer on a conductive substrate, and a photosensitive layer containing a charge generating material and a charge transport material on the undercoat layer, wherein the material of the undercoat layer is provided. Is a copolymer containing an insulating portion and a charge transporting portion, wherein the insulating portion is made of a material that is hardly soluble in a solvent used when applying the photosensitive layer, and the charge transporting portion is the charge An electrophotographic photoreceptor that transports the opposite charge to the transport material. 2. An electrophotographic photoreceptor having at least a subbing layer on a conductive substrate and a photosensitive layer containing a charge generating material and a charge transporting material on the subbing layer, wherein the material for the subbing layer is provided. Is a copolymer containing an insulating portion and a charge transporting portion and having a crosslinked structure, wherein the charge transporting portion transports a charge opposite to that of the charge transporting material. 3. The electrophotographic photoreceptor according to claim 2, wherein the crosslinked structure includes a structure formed by crosslinking an insulating portion of the first copolymer and an insulating portion of the second copolymer. 4. The electrophotographic photoconductor according to claim 2, wherein the copolymer forms the crosslinked structure via a crosslinkable functional group. 5. The electrophotographic photosensitive member according to claim 1, wherein the insulating portion contains a polymer derived from a vinyl monomer. 6. A vinyl monomer represented by the following general formula (I-
at least one of the compounds represented by α) or (I-β)
The electrophotographic photoreceptor according to claim 5, comprising a seed. Embedded image (Wherein, R ^{1 to} R ³ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. R ⁴ has 3 carbon atoms including a fluorine atom. The above substituted alkyl group, a substituted aryl group having 6 or more carbon atoms containing a fluorine atom, a substituted alkyloxycarbonyl group having 3 or more carbon atoms containing a fluorine atom, a substituted alkyloxy group having 3 or more carbon atoms containing a fluorine atom, cyclic or Z represents an oxygen atom, an acyclic amide group, a cyclic or acyclic cyano group, a substituted or unsubstituted cyanoalkyl group, a substituted or unsubstituted cyanoaryl group, or a substituted or unsubstituted carboxylic acid group. Or a substituted or unsubstituted imino group.) 7. A vinyl monomer represented by the following general formula (II):
6. The electrophotographic photoreceptor according to claim 5, comprising at least one compound represented by the following formula and at least one compound having a crosslinkable functional group represented by the following general formula (III). Embedded image (In the general formula (II), R ^{11 to} R ¹³ each independently represent a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl or aryl group, R ¹⁴ represents a halogen atom,
Or a substituted or unsubstituted alkyl group, aryl group,
Represents an alkoxy group, an acyl group, an acyloxy group, or an alkoxycarbonyl group. In addition, general formula (III)
Wherein R ^{15 to} R ¹⁷ each independently represent a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl or aryl group, and R ¹⁸ represents a chlorosulfone group, a carboxyl group, a hydroxy group, a mercapto group, a nitrile group, A substituted alkyl group, a substituted aryl group, a substituted alkoxy group, a substituted acyl group, a substituted acyloxy group, or a substituted alkoxycarbonyl group substituted with an isocyanate group, an amino group, an epoxy group or an alkoxysilyl group. ) 8. A step of preparing a coating solution containing a copolymer containing an insulating portion and a charge transporting portion, and a step of applying the coating solution on a conductive substrate to prepare an undercoat layer. And a method of preparing a photosensitive layer containing a charge generation material and / or a charge transport material on the undercoat layer by a wet coating method after the undercoat layer preparation step. 9. A step of preparing a coating solution containing a copolymer having an insulating portion and a charge transporting portion and having a crosslinkable functional group, and applying the coating solution on a conductive substrate. A step of preparing an undercoat layer by crosslinking the copolymer after or during the coating step, and a step of preparing a photosensitive layer containing a charge generation material and / or a charge transport material after the undercoat layer preparation step. A method for producing an electrophotographic photosensitive member, comprising a step of preparing the undercoat layer by a wet coating method. 10. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1.