JPH02236562A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To maintain good electrostatic characteristics by incorporating a specific macromonomer into a binder resin and incorporating a graft copolymer formed by bonding an acidic group, such as -PO3H2 group or -SO3H group, only to one terminal of the main chain of the polymer therein. CONSTITUTION:The binder resin contains at least one kind of the macromonomers which are expressed by formula I and have 1X10<3> to 2X10<4> weight average mol. wt. as a polymer component and also contains the graft copolymer formed by bonding the acidic group, such as -PO3H2 group or -SO3H group, only to one terminal of the main chain of the polymer. In the formula I, a1, a2, denote a hydrogen atom, cyano group, etc.; X denotes -COO-, -OCO-, etc.; Y denotes a group combining X and -O-; within [ ] is a repeating unit; n denotes 1 to 3 integer; W denotes the groups of the formula II, formula III; R denotes a hydrogen atom or hydrocarbon group. In the formula II, r1, r2 denote a hydrogen atom or alkyl group. The photosensitive body having the excellent electrostatic characteristics and mechanical strength is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor with excellent electrostatic properties, moisture resistance, and durability. (Prior Art) Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied. As representative electrophotographic photoreceptors, there are photoreceptors having a photoconductive layer formed on a support and photoreceptors having an insulating layer on the surface, which are widely used. 'The photoreceptor, consisting of a support and at least one photoconductive layer, is used for image formation by the most common electrophotographic processes, ie, charging, image exposure, development, and, if necessary, transfer. Furthermore, a method of using an electrophotographic photoreceptor as an offset original plate for direct plate making is widely used. The bonding process used to form the photoconductive layer of an electrophotographic photoreceptor has excellent film-forming properties and ability to disperse the photoconductive powder into the binder, as well as excellent dispersion of the photoconductive powder into the binder. In addition, the photoconductive layer of the recording layer has excellent charging ability, low dark decay, large light decay, low pre-exposure fatigue, and changes in humidity during imaging. It is necessary to have various electrostatic properties such as the need to maintain stability and excellent imaging performance. Examples of resins that have been known for a long time include silicone resin (Japanese Patent Publication No. 34-6670), styrene-butadiene resin (
(Japanese Patent Publication No. 35-1960), alkyd resins, maleic acid resins, polyamides (Japanese Patent Publication No. 11219-1987), vinyl acetate resins (Japanese Patent Publication No. 2425-1977), vinyl acetate copolymers (Japanese Patent Publication No. 2426-1977) ,acrylic resin(
(Japanese Patent Publication No. 35-11216), acrylic acid ester copolymers (e.g., Japanese Patent Publication No. 11219/1971, Japanese Patent Publication No. 36/1982)
8510, Special Publication No. 41-13946, etc.) are known. However, electrophotographic materials using these resins lack l) affinity with photoconductive powder;
Poor dispersibility of the coating liquid, 2) Low chargeability of the photoconductive layer, 3) Poor quality of the image area of the copied image (particularly halftone reproducibility and resolution), 4) When creating the copied image. The image quality is easily affected by the environment (e.g. high temperature, high temperature, low temperature and low humidity), 5)
The film strength and adhesion of the photosensitive layer were insufficient, and especially when used as an offset master, there were problems such as detachment of the photosensitive layer during offset printing, making it impossible to print a large number of sheets. Various methods have been proposed to improve the electrostatic properties of the photoconductive layer, and one such method is to use a compound containing a carboxyl group or a ditro group in an aromatic ring or a furan ring, or a dicarboxylic acid anhydride. By combining things further,
A method of coexisting in the photoconductive layer is disclosed in Japanese Patent Publication No. 42-6878,
It is disclosed in Japanese Patent Publication No. 45-3073. However, even with the photosensitive materials improved by these methods, their electrostatic properties are still insufficient, and none with especially excellent light attenuation properties has been obtained. Therefore, in order to improve the lack of sensitivity of this photosensitive material, a method of adding a large amount of sensitizing dye to the photoconductive layer has been conventionally used, but the whiteness of the photosensitive materials produced by this method deteriorates significantly. However, the quality of the recording medium deteriorates, and in some cases, the dark decay of the photosensitive material deteriorates, making it impossible to obtain a sufficient copy image. On the other hand, JP-A-60-10254 discloses a method of adjusting the average molecular weight of a resin as a binder resin for use in a photoconductive layer. That is, an acrylic resin with an acid value of 4 to 50 and an average molecular weight of 10' to 104;
A technique has been described for improving electrostatic properties (particularly good repeatability as an RPC photoreceptor), moisture resistance, etc. by using together components with a distribution of 1 to 2 x 104. Furthermore, research is being carried out on lithographic printing original plates using electrophotographic photoreceptors, and a binder resin for the photoconductive layer that has both the electrostatic properties of an electrophotographic photoreceptor and the printing properties of a printing original plate has been developed. For example, in Japanese Patent Publication No. 50-31011, Mwl. 8X10'～
IOXIO' which uses a resin with TglO ~ 80°C and a copolymer consisting of a (meth)acrylate monomer and a monomer other than fumaric acid, and JP-A-53-5
No. 4027 discloses a method using a terpolymer containing a (meth)acrylic acid ester having a substituent having a carboxylic acid group separated by at least 7 atoms from the ester bond; Kaisho 57-202544
In JP-A-58-68046, a quaternary or penta-component copolymer containing acrylic acid and hydroxyethyl (meth)acrylate is used, and JP-A-58-68046 uses an alkyl group having 6 to 12 carbon atoms as a substituent ( It is described that those using a terpolymer containing a meth)acrylic acid ester and a vinyl monomer containing carbon I are effective in improving the desensitization property of the photoconductive layer. However, even if the resin is said to be effective in the above-mentioned electrostatic properties, moisture resistance properties, and durability,
When actually evaluated, there are problems with electrostatic properties such as chargeability, dark charge retention, photosensitivity, and smoothness of the photoconductive layer.
It was not practically satisfactory. Furthermore, when actually evaluating the binder resin that was said to have been developed as an original plate for electrophotographic lithographic printing, there were problems with the electrostatic properties mentioned above, background smearing of printed matter, etc. Furthermore, in order to solve these problems, a copolymer component containing an acidic group in the side chain of the polymer was used as a binder resin.
Low molecular weight resin containing 5 to 10% by weight (MwlO'~
104), the smoothness and electrostatic properties of the photoconductive layer are improved, and image quality without background smear is obtained. (h% 1104 or more), the film strength of the photoconductive layer can be made sufficient and the printing durability can be improved without impeding the above characteristics.
3-49817, JP-A-63-220148 and JP-A-63-220149. (The invention tries to solve it!ill) However, even if these resins are used, the environment is high temperature and
It has been found that it is still insufficient to maintain stable performance when the temperature fluctuates significantly from high temperature to low temperature and low humidity. In particular, scanning exposure methods using semiconductor laser light require longer exposure times than conventional simultaneous exposure methods using visible light across the entire surface, and there are restrictions on exposure intensity. , higher performance is required in terms of photosensitivity. The present invention is intended to improve the problems of conventional electrophotographic photoreceptors as described above. An object of the present invention is to provide an electrophotographic photoreceptor that stably maintains good electrostatic properties and produces clear, high-quality images even when the environment during copy image formation fluctuates, such as low temperature and low humidity or high temperature and high humidity. It is to provide. Another object of the present invention is to provide a CPC electrophotographic photoreceptor with excellent electrostatic properties and low environmental dependence. Another object of the present invention is to provide an electrophotographic photoreceptor that is effective for scanning exposure using semiconductor laser light. ? Another object of the invention is as an electrophotographic lithographic printing original plate,
It has excellent electrostatic properties (particularly dark charge retention and photosensitivity), reproduces copied images that are faithful to the original, and does not cause not only uniform background smudges on the entire surface of printed matter but also dotted smudges. ,
Another object is to provide a lithographic printing original plate with excellent rigidity resistance.

(Means for Solving the Problems) The above object is to provide an electrophotographic photoreceptor having a light guiding T4 layer containing at least an inorganic photoconductor and a binder resin, wherein the binder resin is represented by the following general formula (1). weight average molecule f
It contains at least one macromonomer of filX10' to 2x104 as a polymerization component, and -PO. l1■ group, -SO3F1 group, -
Contains at least one graft copolymer (hereinafter sometimes referred to as resin (A)) formed by bonding at least one acidic group selected from COOli group I OR (representing a hydrocarbon group) group This is achieved using an electrophotographic photoreceptor that has the following characteristics. General formula (1) at ag Y represents a group connecting X and 10-.

[ ] represents a repeating unit, and n represents an integer from 1 to 3. When n is 2 or more, W in [ ] represents a group different from at least the adjacent W in parentheses. In formula (1), a1 and m may be the same or different, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, -coo-z, or a group having 1 to 8 carbon atoms. -〇〇〇-Z via a hydrocarbon group (Z has 1 carbon number
~18 hydrocarbon groups). X is -C
o O - - O CO - HCH z 7
C O O-, -{co! Fake oco-, → Clh 脣(
28 represents a number from 1 to 3), Pl represents a hydrocarbon group), -CON1ICON}I-
, -CONHCOO- (r+ and r2 may be the same or different and each represents a hydrogen atom or an alkyl group).

R represents a hydrogen atom or a hydrocarbon group. Furthermore, the binding resin is 1X 10' to 2XIO' of the resin (A).
(Hereinafter, this low molecular weight resin (A) may be particularly referred to as resin [A]), and the following resins (B), (C) and (
D) The electrophotographic photoreceptor containing at least one resin further improves the mechanical strength (printing durability when used as a printing plate) of the electrophotographic photoreceptor. ．． Resin (B) has a weight average molecular weight of 5X10' to 5X10' and contains one POillt group, -SO. H group, -Co! Resin containing no basic groups in II groups and OH. Resin (C); 0.1 to 15% by weight of a copolymer component having a weight average molecular weight of 5X10' to 5X10' and containing at least one functional group selected from an OH group and a basic group. Resin [D]; has a weight average molecular weight of 5X10' to 5X10', and has a content of acidic groups of 50% of the content of acidic groups contained in the resin (A) used together.
% or less, or -POsH, which has a pKa larger than the pKa of the acidic group contained in the resin (A) as a copolymerization component, A resin containing a copolymer component containing one type of acidic group. The resin (A) used as the binder resin (A) of the present invention is a graft polymer containing a monofunctional macroheptanomer having a polyether structure represented by the general formula (1) as a copolymerization component. type copolymer, and the graft type copolymer has an acidic group (-
P(hllt group, -SOJ group, -Cool group and /θN The copolymerization content in the polymer of the macromonomer of general formula (1) and/or (II) is per 100 parts by weight,
It is contained in a proportion of 1 to 70 parts by weight. The acidic group bonded to the end of the main chain is present in the polymer at a ratio of 0.5 to 10 parts by weight per 100 parts by weight. The weight average molecular weight of the resin (A) is 1×103 to 5×t
o' is preferred, and more preferably, when the polymer of the present invention has a low molecular weight of IXIO' to 1.5 XIO', the amount of the macromonomer present is 40 to 70 The parts by weight and the amount of the acidic group bonded at the end of the main chain are preferably as large as 3 to 10 parts by weight per 100 parts by weight. On the other hand, the molecular weight of the polymer is 7 x 104 to 5 x 10'
and high molecular weight, the abundance of the macromonomer is
The amount of the acidic group bonded to the end of the main chain is preferably as small as 0.1 to 2 parts by weight per 100 parts by weight. The conventionally known acidic group-containing binder resins as mentioned above are mainly used for offset masters, and have a resistance to 1 g due to the retention of film strength.
In order to improve l1 properties, the molecular weight is large (for example, 5X10' or more), and these copolymers are random copolymers, and the acidic group-containing copolymer component is randomly added to the main chain of the polymer. It existed. On the other hand, the binder resin (A) used in the present invention is a graft copolymer, and the acidic groups contained in the resin are not randomly present in the polymer main chain.
It is a copolymer with specific bonds only at the ends of the main chain. Therefore, the part of the acidic group present at a specific position away from the main chain of the polymer adsorbs to the stoichiometric defects of the inorganic photoconductor, and the part of the main chain of the polymer covers the surface of the photoconductor. It is estimated that the coating is loose and sufficient. Due to that,
It has been found that while compensating for photoconductor trapping and improving humidity characteristics, the photoconductor is sufficiently dispersed and agglomeration is suppressed. In other words, when the weight average molecular weight of the polymer is small, the coverage of the surface of the photoconductor is improved, and in the case of a high molecular weight polymer, the coverage of the photoconductor surface is significantly improved in the case of a random copolymer. This is thought to be due to the suppression of the phenomenon of promoting aggregation among peers. Therefore,
The surface of the photoconductive layer becomes smooth. On the other hand, when a photoreceptor with a rough surface of the photoconductive layer is used as an electrophotographic lithographic printing original plate, the dispersion state of the zinc oxide particles that are the photoconductor and the binder resin is not appropriate, resulting in the presence of aggregates. Since a photoconductive layer is formed in the dry state, even if desensitization treatment is performed using a desensitization treatment liquid, the non-image areas cannot be made uniformly and sufficiently hydrophilic, causing printing ink to adhere during printing, resulting in Background stains occur in the non-image areas of printed matter. On the other hand, when the binder resin (A) according to the present invention is a low molecular weight substance, there was a concern that the film strength would be weakened. It was found that the film retained its film properties and had sufficient film strength to be used as a CPC photoreceptor or as an offset master plate for printing several thousand sheets. Furthermore, it was found that the photosensitivity was better than that of random copolymer resins that contain acidic groups in the side chains that connect to the main chain of the polymer. Therefore, the spectral sensitizing dye that is normally used to maintain photosensitivity in the visible to infrared light range has a sufficient spectral sensitizing effect when adsorbed to the photoconductor.
It is presumed that the binder resin of the present invention interacts appropriately with the photoconductor without inhibiting the adsorption of the spectral enhancing dye. This effect was particularly remarkable with cyanine dyes or lid cyanine pigments, which are particularly effective as spectral enhancing dyes in the near-infrared to infrared region. If the molecular weight of the binder resin (A) is smaller than 103, the film-forming ability will decrease and sufficient film strength cannot be maintained, while if the molecular weight is larger than 5 x 10', the electrophotographic properties ( However, it is not preferable because the initial potential and dark decay retention rate deteriorate.Especially in the case of such a polymer, if the acidic group content exceeds 3ffi, the electrophotographic characteristics deteriorate significantly, and it is difficult to use it as an offset master. Occasionally, scumming becomes noticeable. If the content of acidic groups bonded to the end of the main chain in the binder resin (A) is less than 0.5% by weight, the initial potential will be low and sufficient image density will not be obtained. On the other hand, if the content of acidic groups is more than 10% by weight, dispersibility decreases, film smoothness and high-temperature electrophotographic properties decrease, and furthermore, background smudge increases when used as an offset master. The glass transition point of the resin (A) is -io'c to 100°C
, more preferably -5℃ to 8℃.
It is 5°C. The macromonomer used in the graft copolymer resin containing a macroheptanomer having a polyether structure as a copolymerization component of the present invention will be explained in more detail. In the macromonomer of formula 1a (+), preferably:
at and a. may be the same or different, and each represents a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom,
fluorine atom), cyano group, alkyl group having t to 3 carbon atoms (
For example, methyl group, ethyl group, proyl group, etc.), -co
oz or -CItCOOZ (Z is an alkyl group having 1 to 8 carbon atoms (e.g., methyl group, ethyl group, probyl group, butyl group, bentyl group, hexyl group, octyl group, etc.), an aralkyl group having 7 to 9 carbon atoms ( (e.g., benzyl group, phenethyl group, 3-phenylbrobyl group, etc.) or optionally substituted phenyl group (e.g., phenyl group, tolyl group, xylyl group, methoxyphenyl group, etc.).More preferred <<
In this case, either 1 or h represents a hydrogen atom. X is preferably -COO-, -OCO-, -CO-
, -CI1mC00-, -cotoco-, -CON}
l-, -CONHCON}I-, P1 is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (for example, a methyl group, an ethyl group, a probyl group, a butyl group, a hexyl group, an octyl group,
Decyl group, dodecyl group, 2-methoxyethyl group, 2-chloroethyl group, 2-cyanoethyl group, benzyl group, methylbenzyl group, chlorobenzyl group, methoxyhenzyl group, phenethyl group, phenyl group, tolyl group, chlorophenyl group, methoxyphenyl group, butylphenyl group, etc.). Y represents a group that connects X and 10-, and represents a direct bond or a group that connects. Examples of Y representing a connecting group include a divalent connecting group which may be via a hetero atom (the hetero atom is an oxygen atom, a sulfur atom, or a nitrogen atom), for example, -O- , -S- , -N- , -COO-
, -CONH-, -SO Tomiichi-SOJH-, -NH
It consists of bonding units such as COO-, -NHCONH-, etc., singly or in combination [However, b,, b8
may be the same or different, and each represents a hydrogen atom, a halogen atom (e.g., a chlorine atom, a bromine atom), a hydroxyl group,
Cyano group, aliphatic group having 1 to 12 carbon atoms (e.g., methyl group, ethyl group, probyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, benzyl group, phenethyl group, 2-chloroethyl group, 2-cyanoethyl group, etc.), and P represents the same content as P above.
．． {However, r1, r! may be the same or different, and may be a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (for example, a methyl group, an ethyl group, a proyl group, a butyl group, a hexyl group,
octyl group, etc.}. [ ] represents a repeating unit, and B represents an integer from 1 to 3. However, when n is 2 or more, W in parentheses represents at least a different group from the adjacent W in parentheses, and for example, the following combinations are possible (in each example below, -1, the first trial and 1k each represent a different group and represent the same content as W). -x-y-o-←one+o}-R -X-'l-0-←-t-o)+tit-o
}-R-X Y O +L O)+G1! 03,112-0}-R-X Y O-{-wl O)
-+W* 0)-←Ml-0}-RR represents a hydrogen atom or a hydrocarbon group. The hydrocarbon group includes an optionally substituted alkyl group having 1 to 18 carbon atoms (e.g., methyl group, ethyl group, probyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, octadecyl group) , 2-methoxyethyl group, 3-methoxyethyl group, 2-cyanoethyl group, 2-ethoxyethyl group), optionally substituted aralkyl group having 7 to 9 carbon atoms (e.g. benzyl group, phenethyl group, 3-phenylbrobyl group) , methylbenzyl group, dimethylbenzyl group, methoxybenzyl group, chlorobenzyl group, etc.), alicyclic group having 5 to 8 carbon atoms (e.g. cyclobentyl group, cyclohexyl group, etc.), optionally substituted group having 6 to 12 carbon atoms Aromatic groups (e.g. phenyl group, tolyl group, xylyl group, naphthyl group,
Chlorophenyl group, propophenyl group, alkoxyphenyl group (alkyl group includes methyl group, ethyl group, probyl group, butyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, etc.), acetoxyphenyl group, Methyl-chlorophenyl group, probylphenyl group,
butylphenyl group, decylphenyl group, etc.). 1a Not of the macromonomer in formula (1).
In addition, in each of the following examples, a is -■, -CH3, -C
I! COOCH3, -CZ, -Br or -CN, b represents -■ or -CI13, i represents an integer of 1 or 2, m represents an integer of 2 to 12, k is an integer of 3 or 4 represents. (A-1) CUt■C C○1 (A-2) CH, Cll-C CO- (^-3) CI! -CH-{-CEI. →zCO
-I X -Y - (A-5) b CHz-C Examples include, but are not limited to:
(CI{*}f-C○1 (A-6) b CHtROC CON}l (ljl !}- Go -(A-11)? CH2-C CONH(CI+■Lou(A-t) b CH .TomiC CONHCOO(CllzhE (A-12) ? CI.=C C00(Cltz｝yOco(Cll■te(＾-8) b CH2TomiC CONICONII(CI+2}-Co -(A-13
) b CH*=C C00((HJyO(:OCtl=Cll-CO(A-
14) b (A-10) CHI-C COO(CHz}r- (A45) CI.-CI+ -{- ct5-dan (A-16) b CH!TenC Coo(CI{zteSOtNH (CHz} i-(A-
17)b CI. -C COO(CHx}r- Coo(CIli};-shell formula (
The polyether type macromonomer shown in 1) can be produced by a conventionally known synthesis method. That is,
It is obtained by cationic polymerization of carboxylic acids or alcohols with epoxides or tetrahydrofurans. Specifically, P. F. Remp
p and E. Fra-nta, Adv: Poly
m. Sci. 5B+ 3 (1984)+R. Asa
mi, M. Takaki, K. κita and
E. Asakura, Makromol. Chem.
186. 685 (1985). R. ^satg't
and M. Takaki. Makromol. C
hes+. Suppl. , 12, 163 (198
5). P. Rempp. P le utzP. Masso
n and E. Franta+ Makroa+ol
．． Chem. , Suppl. B3 (1984),
Takuzo Aida. Shohei Inoue. Journal of Organic Synthesis Association, 43. 3
00 (1985) and others. Specific examples of the macromonomer represented by general formula (1) used in the present invention are shown below, but the scope of the present invention is not limited thereto.

Further, in each example, a, b, Q, m, and k represent the same contents as above.

(M-]) b (G2) b (M-3) b (G4) b (?I-5) (M-13) b b (M-15) b The binder resin of the present invention is It is a graft copolymer containing a macromonomer of formula (1) as a copolymerization component, and the other copolymerization components are those that satisfy the physical properties of the binding resin described above, and that are compatible with the macroheptanomer and radicals. Any monomer that can be copolymerized may be used. (G9) (M-10) (M-11) b Preferably, the monomer represented by the following monocatalytic formula (It) is contained as a copolymerization component in an amount of 30% to 99% by weight in the copolymer. ．． X+-R+ In general formula (n), bls bz is a in formula (1)
1.a! represents the same content as, more preferably represents a hydrogen atom or a methyl group. Xt represents -C00-, 10C01 or -O-, preferably -COO-. R● represents a hydrocarbon group having 1 to 18 carbon atoms. Preferably, an optionally substituted alkyl group having 1 to 18 carbon atoms (for example, a methyl group, an ethyl group, a probyl group, a butyl group, a bentyl group, a hexyl group, an octyl group, a decyl group,
Dodecyl group, tridecyl group, tetradecyl group, 2-methoxyethyl group, 2-ethoxyethyl group, 2-hydroxyethyl group, 3-hydroxybrobyl group, 2-hydroxybubutyl group, 2-chloroethyl group, 2-cyanoethyl group , 2-(N,N-dimethylamino)ethyl group, 2.3-
dihydroxypropyl group, 3-canibamoylbutyl group, etc.), optionally substituted aralkyl groups having 7 to 12 carbon atoms (e.g. benzyl group, phenethyl group, methoxybenzyl group, ethoxybenzyl group, methylbenzyl group, dimethylbenzyl group) group, chlorobenzyl group, dichlorobenzyl group, dipromobenzyl group, acetoxybenzyl group, cyanobenzyl group, naphthylmethyl group, 2-naphthylethyl group, etc.), optionally substituted cycloalkyl having 5 to 8 carbon atoms groups (e.g. cyclobentyl group, cyclohexyl group, cycloheptyl group, etc.), optionally substituted aryl groups (e.g. phenyl group, tolyl group, xylyl group, mesityl group, naphthyl group, methoxyphenyl group, ethoxyphenyl group, Chlorophenyl group, dichlorophenyl group,
(promophenyl group, dibromophenyl group, chloroptomophenyl group, acetoxyphenyl group, acetylphenyl group, chloromethyl-phenyl group, promomethyl-phenyl group, cyanophenyl group, methoxycarbonylphenyl group, etc.). Furthermore, the resin of the present invention may contain monomers other than these as copolymerization components together with the macromonomer of general formula (1) and the monomer of general formula (II) described above. For example, α-olefins, vinyl alkanoates or allyl esters, acrylic nitriles, mekuri nitriles, vinyl ethers, acrylamides, methacrylamides, styrenes, heterocyclic vinyl RCs, such as vinylpyrrolidone, vinylpyridine, vinylimidazole , vinylthiophene, vinylimidazoline, vinylpyrazole, vinyldioxane, vinylquinoline, vinylthiazole, vinyloxazine, etc.). However, the content of these other monomers in the copolymer does not exceed 20% by weight.

In the graft copolymer of the present invention, if the copolymerization component corresponding to the macromonomer is less than 1% by weight, it will not be sufficiently dispersed as a photosensitive layer coating material.
If it exceeds 70% by weight, the copolymerization with general formula (II') will not proceed sufficiently, and only the monocatalytic (It) monomer or other monomers will be present in addition to the desired graft copolymer. A polymer is formed. Furthermore, when these resins are used for dispersion, aggregation with the photoconductor occurs. The resin (A) has acidic groups (-PO3H. group, -SO.H group, -Coo}I group,
and R! The hydrocarbon group represented by is the same as the hydrocarbon group represented by R in formula (1). Specifically, methods for producing these resins include a method using a polymerization initiator containing the acidic group or a functional group that can be converted later to replace the acidic group; A method using a chain transfer agent containing a functional group that can be converted into
It can be produced by a method of using both of the above methods in combination, or by a method of introducing the functional group by utilizing a termination reaction in an anionic polymerization method.

For example, P, Dreyfuss+R. P. louirk
, Encycle, Polys+. Sci. Eng. 7
551 (1987), V. f'ercec, Ap
pl. Polym. Sci. 285 95 (1985
), P. F. Rempp, E. Franta,
Adv. Poly1. Sci. 58+ 01984)
, Y. Yamashita, J. Appl.
Polym. Sci. ^ppl. Polym. symp
．． 36, 193 (1981), R. Asaa+
i, M-Takaki+ Makromol. C
hem. Suppl. 12163 (1985) etc. can be produced by the synthesis method cited in the review. In some cases, the electrophotographic photoreceptor of the present invention is desired to have greater mechanical strength while maintaining its excellent electrophotographic properties. For this purpose, a method of introducing a thermally and/or photocurable functional group into the main chain of the graft copolymer can be applied.

That is, in the present invention, a monomer containing at least one heat- and/or photo-curable functional group is copolymerized with the macromonomer of formula (1) described above and preferably the monomer of general formula (n). It is preferable to contain it as Such heat- and/or photo-curable functional groups suitably crosslink the polymers, thereby strengthening the interaction between the polymers and improving the strength of the film. Therefore,
The resin of the present invention further containing such a heat-curable and/or photo-curable functional group strengthens the interaction between the binder resin without hindering the adsorption and coating of the binder resin with the surface of the zinc oxide particles. As a result, it has the effect of further improving the film strength. The heat- and/or photo-curable functional group of the present invention refers to a functional group that can cure a resin with at least one of heat and light. The "thermosetting functional group (functional group that performs a thermosetting reaction)" of the present invention is, for example, the "refined thermosetting polymer of thermosetting polymer" (
C. lI. C■, published in 1986), Yuji Harasaki "Latest Binder Technology Handbook" Chapter ■-I (General Technology Center, 19
(Published in 1985), Takayuki Otsu, “Synthesis, Design, and Development of New Applications of Acrylic Resins” (Chubu Business Development Center Publishing Department, 1988)
The functional groups cited in the references can be used in reviews such as Eizo Omori's "Functional Acrylic Resins" (Technosystem, published in 1985). For example, -Oil group, -St{ group,
-NO snow group, NHR + r group, represent a hydrocarbon group, specifically R. )
, -CONHCH*OR+* (R+2 is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms (e.g., methyl group, ethyl group, proyl group, butyl group, hexyl group, octyl group, etc.)
represents a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, etc.), or an alkyl group having 1 to 4 carbon atoms (for example, a methyl group, an ethyl group, etc.). Moreover, specifically, as the polymerizable double bond group, CHx-ClI
- CH*-CH-CHx-, CL-Ctl-NHC
O-, CHt-CH-Ctlx4}ICO-, CHg=
CI-SOg-, CLl=CIl-CO-, CL-C
ll-0- CHz iris Cll-3-, etc. Examples of the "photocurable functional group" of the present invention include Takahiro Tsunoda, "Photosensitive Resin", Printing Society Publishing Department (1972), Gentaro Nagamatsu, Hideo Inui, "R Photosensitive Polymer", Kodansha (1977).
year) G. A. Delgenne+'f! cycle
pedia or Polye*er Science
and Technology, Suppl+wan
t. "Vol. 1 (1976), etc. can be used. Specifically, addition polymer groups such as allyl ester groups and vinyl ester groups, cinnamoyl groups, optionally substituted maleimide ring groups, etc. can be used. In the present invention, in order to synthesize a resin containing a thermally and/or photocurable functional group, as a copolymer component containing the thermally and/or photocurable functional group, A monomer containing the thermosetting functional group may be used. When the resin of the present invention contains the thermosetting functional group,
In order to promote the crosslinking reaction in the photosensitive layer, a reaction accelerator may be added as necessary. In the case of a reaction mode that forms a chemical bond between functional groups, for example, organic acids (acetic acid,
(propionic acid, butyric acid, benzenesulfonic acid, p-}luenesulfonic acid, etc.), crosslinking agents, and the like. Specifically, as a crosslinking agent, Shinzo Yamashita, Tsukasuke Kaneko, editor.
Compounds described in Crosslinking Agent Handbook J Taiseisha (1981) etc. can be used. For example, commonly used crosslinking agents such as organic silane, polyurethane, polyisocyanate, epoxy resin, melamine resin, etc. A curing agent, etc. can be used. In the case of a polymerizable reaction mode, a polymerization initiator (peroxides, azobis-based compounds, etc., preferably an azobis-based polymerization initiator), a polyfunctional polymerizable initiator, etc. Group-containing monomers (e.g. vinyl methacrylate, allyl methacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, divinyl succinate, divinyl adibate, diallyl succinate,
2-methylvinyl methacrylate, divinylbenzene, etc.). Further, in the present invention, when using a binder resin containing such a thermosetting functional group, a thermosetting treatment is performed. This heat curing process can be performed by tightening the drying conditions during conventional photoreceptor production. For example, 60°C~
The treatment may be carried out at 120° Ct for 5 minutes to 120 degrees. If the above-mentioned reaction accelerator is used in combination, the treatment can be carried out under milder conditions.

In the present invention, the binder resin further includes a low molecular weight (resin (AL) having a weight average molecular weight of 1 x 1O3 to 2 x 104 and the above-mentioned resin CB having a high molecular weight (weight average molecular weight of 5 x 10' to 5 x 1OS)), When either one of (C) and CD) is contained, the mechanical strength of the electrophotographic photoconductor is further improved. Resins [B] to (D) are used to sufficiently level the mechanical strength of the photoconductive layer, which is insufficient with resin (A) alone. (B
) to (D) in combination, the electrophotographic photoreceptor of the present invention has good surface smoothness of the photoconductor layer even when used as an original plate for electrophotographic lithography, and the photoconductor layer has good surface smoothness. Since the zinc oxide particles, which are Adhesion to non-image areas is suppressed, and background smudges do not occur even when a large number of prints, such as 10,000, are printed.

That is, in the present invention, resin (AL) and resin (B) - (
When one of D) is used in combination, the adsorption/coating interaction between the inorganic photoconductor and the binder resin is properly performed, and the film strength of the photoconductive layer is better maintained.

In the resin (AL), the amount of the macroheptanomer (formula (I)) in the copolymer is 10% of the resin (AL), 1%
It accounts for 40 to 70% by weight. The weight average molecular weight of the resin (AL) is preferably IXIO' to l. 5 x 10', more preferably 3XlO' to 1. OX 10'.

In the binder resin used in the present invention, a low molecular weight resin (
The case where ALI is used in combination with the high molecular weight resin CB) which does not contain any acidic groups or basic groups will be described in detail.

The resin that can be used in the present invention (Bl does not contain the above-mentioned acidic groups (main chain terminal acidic groups contained in resin (A)) in either the polymer main chain or the terminal, and also contains a basic group. It is a resin with a weight average molecular weight of 5X10' to 5X10'.More preferably a weight average molecular weight of 18X10' to 5X10'.
3XIO'.

The glass transition point of resin CB) is preferably 0°C to 120°C.
The temperature range is preferably 10°C to 80°C. As the resin (B), any of those conventionally used as binder resins for electrophotography may be used, and they may be used alone or in combination. For example, Harumi Miyahara, Hidehiko Takei, “Imaging J 1978 No.
8 9-12, Ryuji Kurita, Jiro Ishiwatari, "Polymer", 1
7. 278-284 (1968) and other review articles cited. Specifically, olefin polymers and copolymers, vinyl chloride copolymers, vinylidene chloride copolymers, vinyl alkanoate polymers and copolymers, allyl alkanoate polymers and copolymers, styrene and its derivatives, Polymers and copolymers, butadiene-styrene copolymers, isobrene-styrene copolymers, butadiene-unsaturated carboxylic acid ester copolymers, acrylonitrile copolymers, methacrylic nitrile copolymers, alkyl vinyl ether copolymers, Acrylic ester polymers and copolymers, methacrylic ester polymers and copolymers, styrene-acrylic ester copolymers, styrene-methacrylic ester copolymers,
Itaconic acid diester polymers and copolymers, maleic anhydride copolymers, acrylamide copolymers, methacrylamide copolymers, hydroxyl-modified silicone resins, polycarbonate resins, ketone resins, amide resins, hydroxyl- and carboxyl-modified polyester resins , butyral resin, polyvinyl acetal resin, cyclized rubber-methacrylic ester copolymer, cyclized rubber-acrylic ester copolymer, copolymer containing a heterocycle containing no nitrogen atom (?
Examples of monocyclic rings include furan ring, tetrahydrofuran ring, thiophene ring, dioxane ring, dioxolane ring, lactone ring, penzofuran ring, penzothiophene ring, 1,3
- dioxecune ring, etc.) epoxy resins, etc. More specifically, a (meth)acrylic copolymer containing at least one monomer represented by the following general formula ([I) in a total amount of 30% by weight or more as a (co)polymer component. Alternatively, polymers can be cited as examples of resin (B). General formula (III) d3 In formula (IV), d is a hydrogen atom, a halogen atom (e.g., a chloro atom, a bromo atom), a cyano group, or a carbon number of 1 to
represents an alkyl group having 4 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms. R' is an optionally substituted alkyl group having 1 to 1 carbon atoms (e.g., methyl group, ethyl group,
probyl group, butyl group, bentyl group, hexyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, 2-methoxyethyl group, 2-ethoxyethyl group, etc.), substituted with 2 to 18 carbon atoms. alkenyl groups (e.g., vinyl, allyl, isobropenyl, butenyl, hexenyl, hebutenyl, octenyl, etc.), optionally substituted aralkyl groups having 7 to 14 carbon atoms (e.g., benzyl, phenethyl, methoxybenzyl group, ethoxybenzyl group, methylbenzyl group, etc.), optionally substituted cycloalkyl groups having 5 to 8 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, cycloheptyl group, etc.), aryl groups (e.g., phenyl group), base,
Represents tolyl group, xylyl group, mesityl group, naphthyl group, methoxyphenyl group, ethoxyphenyl group, chlorophenyl group, dichlorophenyl71) R l is preferably an alkyl group having 1 to 4 carbon atoms, or an alkyl group having 7 to 14 carbon atoms. an optionally substituted aralkyl group (particularly preferred are an optionally substituted benzyl group, phenethyl group, naphthylmethyl group, and 2-naphthylethyl group), or an optionally substituted phenethyl group or Naphthyl group (Substituents include chlorine atom, bromine atom, methyl group, ethyl group, probyl group, acetyl group, methoxycarbonyl group, ethoxy carbonyl group, etc.) These substituents are substituted with 2 or 3 ). Furthermore, as a component copolymerizable with the above (meth)acrylic acid ester in the resin (B), -a formula (II
Monomers other than I) may be used, such as α-olefins, vinyl alkanoates or allyl esters, acrylonitrile, methacrylonitrile, vinyl ethers, acrylamides, methacrylamides, styrenes, heterocyclic vinyl [For example, nonmetallic atoms other than nitrogen atoms (
5-7 members containing 1-3 oxygen atoms, sulfur atoms, etc.
It is a membered heterocycle, and specific examples include vinylthiophene, vinyldioxane, vinylfuran, etc. As a preferable example, for example, carbon number 1-3
vinyl alkanoates or allyl esters, acrylonitrile, methacrylonitrile, styrene and styrene derivatives such as vinyltoluene, butylstyrene, methoxystyrene, chlorostyrene, dichlorostyrene, promostyrene, ethoxystyrene, etc.). On the other hand, examples of the basic group not contained in the resin CB) that can be used in the present invention include an optionally substituted amino group and a nitrogen atom-containing heterocyclic group. Next, in the binder resin provided in the present invention, the above-described low molecular weight resin [^L], a high molecular weight resin (C) containing at least one of an O}l group and a basic group, and This section describes in detail the case where these are used in combination. In the resin (C), the proportion of the copolymerized component containing 1011 groups and/or basic groups is 0.05 in the resin (C).
15% by weight, more preferably 0.5 to 10% by weight. The weight average molecular weight of resin (C) is 5X10'
~5X10', preferably 8x104~10'
It is. The glass transition point of the resin (C) is preferably o”
c to 120°C, more preferably 10°C to 80°C
It is. In the present invention, the 011 group component or basic group component in the resin (C) has a weak interaction with the photoconductor particle interface and the resin (AL), thereby stabilizing the dispersion of the photoconductor dispersion. It is also thought to have the effect of further improving the film strength after film formation. However, if the proportion of these components in the resin (C) exceeds 15% by weight, the photoconductive layer will be affected by moisture and the moisture resistance of the photoconductive layer will decrease. As the resin (C), conventionally known resins such as those described for the resin (B) can be used as long as they have the physical properties described above. More specifically, the resin (C) is a (meth)acrylic copolymer containing 1% or more of the monomers represented by the general formula (I [[) in total as copolymer components. This can be cited as an example. rO contained in resin (C)
The "copolymerization component containing an H group and/or a basic group" is a vinyl compound containing the substituent (OH group and/or basic group) that can be copolymerized with the general formula (1) above. You can use either. Examples of the basic group include an amino group and a nitrogen atom-containing heterocyclic group represented by the following general formula (IV). General formula (IV) In formula (IV), Lx and RI4 may be the same or different, and each represents a hydrogen atom, an optionally substituted alkyl group (for example, a methyl group, an ethyl group, a proyl group, a butyl group,
Hexyl group, octyl group, decyl group, dodecyl group, tetradecyl group, octadecyl L2-promoethyl group, 2-
chloroethyl group, 2-hydroxyethyl group, 2-cyanoethyl group, 2-methoxyethyl group, 3-ethoxybutyl group, etc.), optionally substituted alkenyl groups (e.g. allyl group, isobrobenyl group, 4-butynyl group, etc.) ), ff#
Aralkyl groups (for example, benzyl group, phenethyl group, chlorobenzyl group, methylbenzyl group, methoxybenzyl group, hydroxybenzyl group, etc.), alicyclic groups (for example, cyclobentyl group, cyclohexyl group, etc.), aryl groups (for example, cyclobenzyl group, cyclohexyl group, etc.), which may be For example, phenyl group, tolyl group, xylyl group, mesityl group, butylphenyl group, methoxyphenyl group, chlorophenyl group, etc.). Furthermore, R1, and Rl
4 may be connected via a hydrocarbon group, which may be via a hetero atom. Furthermore, as a nitrogen atom-containing heterocycle, 1 to 3 nitrogen atoms are used.
These heterocycles may further include a benzene ring, a naphthalene ring, etc. to form a condensed ring. Furthermore, these rings may contain substituents. Specifically, for example, pyrrole ring, imidazole ring, pyrazole ring, biridine ring, biverazine ring, birimidine ring, pyridazine ring, indolizine ring, indole ring, 2H-virol fi, 3H-
Indole ring, indazole ring, purine ring, morpholine ring, isoquinoline ring, phthalazine ring, naphthyridine ring,
Quinoxazine ring, acridine ring, phenanthridine ring,
Phenazine ring, pyrrolidine ring, viroline ring, imidazolidine ring, imidazoline ring, virazolidine ring, birazoline ring, piperidine ring, piperazine ring, quinacridine ring, indoline ring, 3,3-dimethylindolenine ring, 3,3
-dimethylnaphthoindolenine ring, thiazole ring, penzothiazole ring, naphthothiazole ring, oxazole ring, penzoxazole ring, naphthoxazole ring, selenazole ring, penzoselenazole ring, naphthoselenazole ring, oxazoline ring, isoxazole ring, penzoxazole ring, morpholine ring, pyrrolidone ring, triazole ring, penzotriazole ring, triazine ring and the like.

These 011, li and/or basic groups can be used, for example, in the Polymer Data Handbook [Basic kIA
]” Baifukan (1986) etc., the desired monomer can be incorporated into the substituent of an ester derivative or amide conductor derived from a vinyl group-containing carboxylic acid or sulfonic acid. can get. For example, 2-hydroxyethyl methacrylate, 3-hydroxybutyl methacrylate, 3-hydroxy-2-chloromethacrylate, 4-hydroxybutyl methacrylate, 6-hydroxybutyl methacrylate,
Hydroxyhexyl methacrylate, lO-hydroxydecyl methacrylate, N-(2-hydroxyethyl)acrylamide, N-(3-hydroxypropyl)methacrylamide, N-(α,α-dihydroxymethyl)
Ethylmethacrylamide-N-(4-hydroxybutyl)methacryl! Reamide, N,N-dimethylaminoethyl methacrylate, 2-(N,N-diethylaminoethyl)methacrylate, 3-(N,N-dimethylbuchivil)
methacrylate, 2-(N,N-dimethylethyl)methacrylamide, hydroxystyrene, hydroxymethylstyrene, N. N-dimethylaminomethylstyrene, N
．． N-diethylaminomethylstyrene, N-butyl-N
Examples include various monomers such as -methylaminomethylstyrene and N-(hydroxyphenyl)methacrylamide.
As a vinyl compound having a nitrogen atom-containing heterocycle,
For example, the above-mentioned "Polymer Data Handbook [Basic Edition]" No. 175. 〜181 pages, D. A. Tosa eyes a,
rReactiva Ilateracyclic
Monomers”chap 1 of”F
Unctional Monomers Vol.
2Z Mar-csl DeRRsr Inc. N.
Y. (1974), L. S. LusRinrBas-
ic Monomers J chap 3 of
@Functional Monom-ers Vol.
．． 2”, MarcelDeRRer Inc.N.
Y. (1974) and the like. Furthermore, the resin (C) may contain monomers other than these as copolymerization components together with the monomers containing the Ol (group and/or basic group) described above. For example, resin (C)
Specific examples include monomers similar to those described in B) as being able to be contained as other copolymerization components. Next, in the binder resin provided in the present invention, the low molecular weight resin (AL) and the content of acidic Go contained in the resin (AL) have a content of 50% or less, preferably 30% or less. Acidic groups can be used as side chains of copolymerization components, or resins (AL
The case where an acidic group having a larger pKa than the acidic group contained in ) is used as a side chain of the copolymerization component in combination with the high molecular weight resin (D) contained will be described in detail. The weight average molecular weight of the resin (D) is 5 x 10' to 5 x 10'
However, 7X10' to 4X10' is preferable. resin(
The acidic group contained in the side chain of the polymer D) is preferably contained in the resin (D) in a proportion of 0.05 to 3% by weight. More preferably, it is 0.1 to 1.5% by weight. Further, it is preferable that acidic groups are included in the red resin (D) in combinations shown in Table A below. Table 18 The glass transition point of the resin (D) is preferably 0°C to 120
°C range, more preferably O'C to 100'C. More preferably it is 10°C to 80°C. Resin C
D) is more sensitive to photoconductor particles than resin [^L].
It exhibits a very weak interaction and has the function of gently covering the film, and without sacrificing the function of the resin [^L], it can provide sufficient mechanical strength to the photoconductive layer, which is insufficient with the resin (AL) alone. It is something to tighten. Furthermore, if the content of side chain acidic groups in the resin (D) exceeds 3% by weight, adsorption of the resin (D) to the photoconductor particles will occur, destroying the dispersion of the photoconductor and forming aggregates or precipitates. The electrostatic properties of the resulting photoconductor may deteriorate significantly, or the smoothness of the photoconductor surface may deteriorate. This is undesirable because the surface becomes rough and the strength against mechanical wear deteriorates. In the P-OR3 group in I1 resin (D), R is more specifically, for example, an optionally substituted alkyl group having 1 to 12 carbon atoms (e.g., methyl group, ethyl group, proyl group, butyl group). group, hexyl group, octyl group, decyl group,
dodecyl group, 2-chloroethyl group, 2-methoxyethyl group, 2-ethoxyethyl group, 3-methoxybrobyl group, etc.), optionally substituted aralkyl group having 7 to 12 carbon atoms (e.g. benzyl group, phenethyl group) , chlorobenzyl group, methoxybenzyl group, methylbenzyl W, etc.), an optionally substituted alicyclic group having 5 to 8 carbon atoms (e.g. cyclopentyl group, cyclohexyl group, etc.) or an optionally substituted aryl group ( For example, phenyl group, tolyl group,
(xylyl group, mesityl group, naphthyl group, chlorophenyl group, methoxyphenyl group, etc.). The resin (D) may be any conventionally known resin as long as it has the physical properties described above, and for example, the conventionally known resins described in Resin CB) can be used. More specifically, an example of the resin CD) is an acrylic copolymer containing a total amount of 30% by weight or more of the monomer represented by the general formula (III) as a copolymer component. be able to. Resin CD provided for the present invention)
The "copolymer component containing an acidic group" can be any vinyl compound containing an acidic group that can be copolymerized with the above-mentioned general formula (1).
For example, ``Polymer Data Handbook'' edited by the Polymer Science Society of Japan.
Basic Edition] Baifukan (published in 1986), etc.
Specifically, acrylic acid, α and/or βtta acrylic acid (e.g. α-acetoxy form, α-acetoxymethyl form, α-1(2-amino)methyl form, α-chloro form, α-bromo form, α-fluoro form) body, α-tributylsilyl body, α-
Cyano form, β-chloro form, β-bromo form, α-chloro-β
-methoxy, α,β-dichloroform, etc.), methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid half amides, crotonic acid, 2-alkenylcarboxylic acids (
For example, 2-bentenoic acid, 2-methyl-2-hexenoic acid,
2-octenoic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-octenoic acid, etc.), maleic acid, maleic acid half esters, maleic acid half amides, vinylbenzenecarboxylic acid, vinylbenzenesulfonic acid, Examples include half-ester derivatives of vinyl or allyl groups of vinyl sulfonic acid, vinylphosphonic acid, and dicarboxylic acids, and compounds containing the acidic group in the substituent group of ester derivatives and amide derivatives of these carboxylic acids or sulfonic acids. ．． Specific examples of these compounds include the following. However, in each of the following examples, e is -H, -C
Ilff, -CI, -Br, -CN-, -CIlg
COOC}l. or -CH. COOl+, f is -
11 or -CHs, n1 represents an integer from 2 to l8, cap represents an integer from 1 to l2, and 2. represents an integer from 1 to 4.

coz=ci COOH CH3 CII=CI COOI+ f f CHt=C CONII(CHz)r++cOOH f? I1■”” CH Cl *OCO (CH z)
Ill + COOHCHHz=CH+CIIg〒co
on l: integer from 1 to 4 f f f (l1) f C113 CI{ffi=c? Il■COOH CONICI1 CI2COOH (l3) f (l4) f CIh=C Coo (CH z) m lNIICO (CH z
) m, COOH (m+ may be the same or different) f f 0H ' f 0H f 0H f ■ CL-C COO (CHz) lTl+sOsH υ■ f f CH! =C COO(CL),, CON(CIIzCHzCOOH
) 2f f しυu■ f Furthermore, the resin CD) of the present invention can be copolymerized with the monomer of the general formula CDI) and the monomer containing an acidic group, as well as other monomers other than these. May be included as an ingredient. For example, the same monomers described as being able to be contained as other copolymerization components in resin (B) can be cited as specific examples. Furthermore, the resin (AL) and resin (C) or (D) of the present invention
Other resins can also be used in combination.

Examples of such resins include alkyd resins, polybutyral resins, polyolefins, ethylene-vinyl acetate copolymers, styrene resins, styrene-butadiene resins, acrylate-butadiene resins, vinyl alkanoate resins, and the like. The other resins mentioned above are all binder resins IIl using the resin of the present invention.
If the amount (AL) and CC) or (D) exceeds 30% (weight ratio), the effects of the present invention (especially improvement in electrostatic properties) will be lost. The ratio of the amount of the resin (AL) used in the present invention to any one of the resins (B) to (D) varies depending on the type, particle size, and surface condition of the inorganic photoconductive material used, but generally the resin The ratio of (AL) and any of the resins (B) to (D) used is 5 to 80 to 95 to 20 (ffifi ratio), preferably 15 to 60 to 85 to 40 (weight ratio). The ratio of the weight average molecular weight of the resin (AL) to any one of the resins (B) to (D) is preferably 1.2 or more, more preferably 2.0 or more. Inorganic photoconductive materials used in the present invention include zinc oxide,
Examples include titanium oxide, zinc sulfide, cadmium sulfide, cadmium carbonate, zinc selenide, cadmium selenide, tellurium selenide, lead sulfide, etc. The total amount of binder resin used for the inorganic photoconductive material is 10 to 100 parts by weight, preferably 15 to 50 parts by weight, per 100 parts by weight of the photoconductor. ．． In the present invention, various dyes can be used in combination as spectral sensitizers, if necessary. For example, Harumi Miyamoto, Hidehiko Takei, "Imaging" plate (No. 8), p. 12, C. J
．． Young et al., RCA Review ball 469 (
1954), Wataru Kiyota, Journal of the Institute of Electrical Communication, 97 (1980), Yuji Harasaki et al., Industrial Chemistry Journal fifi7B and 188 (1963), Tadaaki Tani, Journal of the Photographic Society of Japan, 208 (1972) ), carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein dyes, vorimethine dyes (e.g., oxonol dyes, merocyanine dyes, cyanine dyes, logcyanine dyes, styryl dyes, etc.), Examples include lid cyanine dyes (which may contain metal). More specifically, examples of those mainly using carbonium dyes, triphenylmethane dyes, xanthene dyes, and phthalein dyes include Japanese Patent Publication No. 51-452, Japanese Patent Application Publication No. 50-90334, and Japanese Patent Application Laid-open No. 1987-90334. -114227, JP 53-39130, JP 53-82353,
U.S. Patent No. 3.052,540, U.S. Patent No. 4.05
Examples include those described in No. 4.450, JP-A-57-16456, and the like. Examples of vorimethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes, and logocyanine dyes include P. M. IIarsmer rThe
Cyanine Dyes andRelated C
It is possible to use dyes described in US Pat. No. 3,047,384, US Pat. No. 3,110,591, US Pat.
No. 21.008, U.S. Patent No. 3. 125,447, U.S. Pat. No. 3,128,179, U.S. Pat.
．． No. 132,942, U.S. Patent No. 3.622.317, British Patent No. 1.226.892, British Patent No. 1.3
09,274, British Patent No. 1,405,898, Japanese Patent Publication No. 48-7814, Japanese Patent Publication No. 18892-1987, and the like. Furthermore, as a polymethine dye that spectrally sensitizes the near-infrared to infrared light region with a long wavelength of 700 nm or more, JP-A-47-840, JP-A-47-44180, JP-A-51-41061, JP-A-Sho No. 49-5034, JP-A-49-45122, JP-A-57-46245
No., JP-A-56-35141, JP-A-57-1572
No. 54, JP-A-61-26044, JP-A-61-27
No. 551, U.S. Patent No. 3,619,154, U.S. Patent No. 4,175,956, rResearch Dis
closure J 1982, 216, 117th~
Examples include those described on page 118. The photoreceptor of the present invention is excellent in that its performance is unlikely to be affected by sensitizing dyes even when used in combination with various sensitizing dyes. Furthermore, if necessary, various conventionally known additives for electrophotographic photosensitive layers, such as chemical thickening agents, may be used in combination. for example,
Review mentioned above: Imaging 1973 (No. 8) No. 1
Electron-accepting compounds (e.g., halogens, penzoquinone, chloranil, acid anhydrides, organic carboxylic acids, etc.) cited in the review on page 2, Hiroshi Komon et al., "Recent development and practical application of photoconductive materials and photoreceptors" Chapters 4 to 6: Japanese Science Information ■Publishing Department (
Examples include polyarylalkane compounds, hindered phenol compounds, P-phenylenediamine compounds, etc. cited in the review of 1986).

The amount of these various additives added is not particularly limited, but
Usually 0.0001 to 2.0 parts per 100 parts by weight of photoconductor.
It is 0 parts by weight. The thickness of the photoconductive layer is preferably 1 to 100 μm, particularly 10 to 50 μm.

In addition, when a photoconductive layer is used as a charge generation layer in a laminated type photoreceptor consisting of a charge generation layer and a charge transport layer, the thickness of the charge generation layer is 0.01 to 1μ, particularly 0.05 to 0.5μ. It is suitable. In some cases, an insulating layer is added mainly for the purpose of protecting the photoreceptor, improving its durability, dark decay characteristics, etc.

At this time, the insulating layer is set to be relatively thin, and when the photoreceptor is used in a specific electrophotographic process, the insulating layer provided is set to be relatively thick.

In the latter case, the thickness of the insulating layer is between 5 and 70μ, in particular 1
It is set to 0 to 50μ.

Charge transport materials for laminated photoconductors include polyvinyl rubazole, oxazole dyes, birapurine dyes, and triphenylmethane dyes. The thickness of the charge transport layer is preferably 5 to 40 microns, particularly 10 to 30 microns. Typical resins used to form the insulating layer or charge transport layer include polystyrene resin, polyester resin, cellulose resin, polyether resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acid copolymer resin, Thermoplastic resins and curable resins such as polyacrylic resins, polyolefin resins, urethane resins, epoxy resins, melamine resins, and silicone resins are used as appropriate. The photoconductive layer according to the present invention can be provided on a conventionally known support. Generally speaking, the support for the electrophotographic photosensitive layer is preferably electrically conductive.As the electrically conductive support, for example, a low-resistance material is coated on a base material such as metal, paper, or plastic sheet, just as in the conventional case. Those that have been subjected to conductive treatment such as impregnating them, those that have been coated with at least one layer for the purpose of imparting conductivity to the back surface of the substrate (the surface opposite to the surface on which the photosensitive layer is provided) and further preventing curling, etc. Those with a water-resistant adhesive layer on the surface of the support, those with at least one or more pre-coated layers provided on the surface layer of the support as required, and those with conductive plastic on which AI or the like is deposited on paper. Laminated materials can be used. Specifically, examples of conductive substrates or conductive materials include:
Yukio Sakamoto, “Electronic Photography J, 14 (No. 1), P2~
11 (1975), Hiroyuki Moriga, "Introductory Chemistry of Special Papers", Kobunshi Publishing (1975), M,F. I{over,
J. Macromol. Sci. Chem. A-
4 (6), pp. 1327-1417 (1970)
Use those listed in etc.

(Example) Examples of the present invention are illustrated below, but the content of the present invention is not limited to these. Synthesis example 1 of resin (A) of the present invention: (A-1) Penzyl methacrylate 60
A mixture of 20 g of methyl acrylate, 20 g of macroheptanomer (1) having the following structure, and 200 g of toluene was heated to 70° C. under a nitrogen stream. 4.4°-azobis(4-cyanovaleric acid) (abbreviation A.C.V) 1.
Add 0g and stir for 4 hours. Furthermore, A. C. V. 0.
Add 4g and dry for 2 hours.A. 1. V. 0.2g
was added and stirred for 3 hours. The weight average molecular weight (abbreviation Mw) of the obtained copolymer was 4.5×10′. ? Coo +-ClitCIl■o±11 Synthesis Examples 2 to 7 of Resin (A) of the Present Invention: (^-2) to (A-7) In Il) of Synthesis Example 1 of Resin (A), macromonomer (
MM-1) FF The macromonomer shown in Table 21 has {t,
The resins (A) shown in Table 1 below were synthesized by carrying out the reaction in the same manner as in Synthesis Example 1 except for the above. The resulting copolymer cage was 4
xto'~5.5X10'. The resin of the present invention (
Synthesis example 8 of A): 60 g of A-8 pendyl methacrylate
, 40 g of macromonomer (MM-8) with the following structure,
A mixed solution of 150 g of toluene and 50 g of isobrobyl alcohol was heated to a temperature of 80°C under a nitrogen stream. A. C. V. 5.0 g was added and stirred for 4 hours. Sarani A
．． C. V. Add 1.0g for 2 hours, then add A. C.
V,Q. 5 g was added and stirred for 3 hours. The weight average molecular weight of the obtained copolymer was 8.3 x 10'. (MM-8) C113 Synthesis example 9 of resin (A) of the present invention: (A-9) 50 g of pendyl methacrylate, a macromonomer with the following structure (
A mixed solution of 50 g of MM-9), 4.0 g of thioglycolic acid, and 200 g of toluene was heated to a purity of 75"C under a nitrogen stream.
It was heated to 2. 1.5 g of 2'-azobisisobutyronitrile (abbreviated as iA.I.B.N.) was added and stirred for 4 hours, and then A.I.B.N. I. B. N. Add 0.4g for 2 hours, then add A. I. B. N. 0.2 g was added and stirred for 3 hours. What is the weight average molecular weight of the obtained copolymer? ．． O
It was X 10'. (MM-9) CHs Book 6. OX10” Honichi〇00〇HtC}IzO{-(CIlz)nO }
CtHs Example 1 and Comparative Example A Resin of Resin Synthesis Example 1 (^-1) 40g (as solid content), zinc oxide 200g, cyanine dye (1) having the following structure 0.018g, phthalic anhydride 0. 10
A mixture of g and 300 g of toluene was boiled in a Pall mill for 2 hours to prepare a photosensitive layer-forming material, and this was applied to electrically conductive treated paper using a wire bar so that the dry adhesion amount was 20 g/rrl. An electrophotographic light-sensitive material was prepared by drying at 110°C for 30 seconds, and then leaving it in the dark under 200C65%Rl1 conditions for 24 hours. Cyanine dye ([] Comparative resin (P-1) C00(C11z)gOcO(Cllt)zcO
OH weight average molecular weight: 3.8xlO' Film properties (surface smoothness), film strength,
The electrostatic properties, imaging performance, and imaging performance when the environmental conditions were 30'C and 80% RH were investigated. Furthermore, when these photosensitive materials are used as original plates for offset masters, the desensitization of photoconductivity (represented by the contact angle with water of the photoconductive layer after desensitization treatment) and printability (background smudge, The printing durability, etc.) were investigated. The above results are summarized in Table 2. Comparative Example A Resin (A-1) used as binder resin in Example 1
An electrophotographic material was prepared in the same manner as in Example 1, except that 40 g of resin (P-1) having the following structure was used instead of . Table 2 The implementation of the evaluation items shown in Table 2 is as follows. Note 1) Smoothness of photoconductive layer: The obtained photosensitive material was tested using a Beck smoothness tester (Kumagai Riko ■
The smoothness (
sec/cc) was measured.

Note 2) Mechanical strength of photoconductive layer: The surface of the obtained photosensitive material was tested using Heidon-14 type surface test material (
(manufactured by Shinto Kagaku ■) under a load of 50 g/c + J, and was repeatedly probed with emery paper (11000) 1000 times to remove abrasion powder and determine the remaining film rate (Z) from the weight loss of the light-transmitting layer, which was determined as mechanical strength. .

Note 3): Electrostatic properties: In a dark room at a temperature of 20°C and 65% Rl+, each luminescent material was subjected to corona discharge at -6 kV for 20 seconds using a paper analyzer (Kawaguchi Electric 0 grade paper analyzer SP-428 model). After this, the surface potential νl was measured after being left for 10 seconds. Then, the potential V+@ after being allowed to stand still in the dark for 180 seconds. The retention of the potential after dark decaying for 180 seconds, that is, the dark decay retention rate (DRR (!
) was calculated using (V+s*/V+o)XIOO(X)).
After the surface of the photoconductive layer was charged to -400V by corona discharge, it was irradiated with monochromatic light with a wavelength of 780 nm to increase the surface potential +
V'1. ) is attenuated to 1/10, and from this, the exposure R E + y +. (erg/c4) is calculated.

Note 4) Imaging performance: Each photosensitive material was left for one day and night under the following environmental conditions.

Next, the surface of the photosensitive material was charged at -5 KV, and a 64 erg.
/cIa dose, pitch 25I! After exposure, the copied image (fogging,
Image quality) was visually evaluated.

The environmental conditions at the time of imaging are 20°Cε5%l? I+ and 30℃8
Performed at 0% Rl+.

Note 5) Contact angle with water: After each photoconductive material was passed through an etching processor once using a desensitizing liquid ELP-EX (manufactured by Fuji Photo Film) to desensitize the photoconductive layer surface. A droplet of 2 μl of distilled water is placed on this, and the contact angle with the water formed is measured using a goniometer.

Note 6) Each stiffness-resistant photosensitive material is plate-made to form a toner image under the same conditions as Note 4) above, and desensitized under the same conditions as Note 5) above, and this is used as an offset master. The number of sheets that can be printed on an off-cent printing machine (Oliver Model 52, manufactured by Sakurai Seisakusho ■) without causing problems with scumming in the non-image areas of the prints or problems with the image quality of the image areas is not indicated. Good J
(represents childishness).

Note 7): DII1 (image density) Indicates the maximum value at the toner image density in the rough area (can be measured with a Maches reflection densitometer).

As shown in Table 2, the photosensitive materials of the present invention and Comparative Example A had good smoothness and electrostatic properties of the photoconductive layer, and the actual copied images had no ground blur and the quality of the copied images was clear. This is presumed to be due to the fact that the photoconductor and the binder resin are properly adsorbed and cover the particle surface, and do not inhibit the adsorption of the spectral enhancement dye.

For the same reason, even when used as an offset master original, the desensitization treatment with the desensitization treatment liquid progresses sufficiently, and the contact angle with water in the non-image area is small at 15 degrees or less, making it sufficiently hydrophilic. ing. When I actually printed and observed the background stains on the printed matter, I could not find any stains at all. However, in the case of Comparative Example A, although the film strength was sufficient,
Electrostatic properties, especially D. l? ．． R was significantly lowered, and even if one image was actually taken, a sufficient copy image could not be obtained *El/l. The apparent smaller size is due to D. R
．． R. This was different from the so-called good photoconductivity, which produces conductivity when exposed to light. This is because the conventional random copolymer resin covers the surface of the oxidized subparticles excessively and strongly, inhibiting the adsorption of the dye to the particle surface and deteriorating the electrostatic properties. The photosensitive material of the present invention has excellent smoothness, film strength, electrostatic properties, and The printability was good in all respects.

Examples 2 to 7 In Example 1, instead of 40 g of resin (A-1),
Each resin (^-
Each photosensitive material was produced in the same manner as in Example 1, except that 40 g of 2) to (A-7) was used. In the same manner as in Example 1, the smoothness, II strength, and electrostatic properties of each photosensitive material were measured and are listed in Table 3.

Table 3 Each of the photosensitive materials of the present invention has excellent chargeability, dark charge retention rate, and photosensitivity, and the actual reproduced images can be used at high temperatures (30°C, 80%
Even under the harsh conditions of R11), it provided clear images with no occurrence of ground blur or fine line skipping. Furthermore, when printed as an offset master master plate, we were able to print over 7,000 sheets with clear images without any blurring in the non-image areas. Example 8 In Example 1, instead of 40 g of resin (A-1),
Resin (a-8) 8g (as solid content) and poly(ethyl methacrylate) (weight average molecule it 3.4X10
) [An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that 332 g of resin (B-1) was used. The characteristics of the obtained photoreceptor were measured in the same manner as in Example 1. The surface smoothness of the photoconductive layer was 98 (see/cc) and smooth, V+e: -580V, D. R. R: 86χ, El/
+0 27 (erg/cd), (30℃, 80%
The image quality was also good for Rl+). The luminescent material of the present invention has excellent chargeability, dark charge retention rate, and photosensitivity, and the actual copied images are also kept at high temperatures (30°C, BO%R).
Even under the harsh conditions of (I), it provided clear images with no occurrence of ground blur or fine line skipping. Furthermore, when printed as an offset master master plate, we were able to print over 10,000 sheets of clear images with no ground blur in the non-image areas. Example 9 In Example 8, instead of the resin (A-8> 8 g... fat (^-3) 8 g, and instead of the resin (B-1), poly(butyl methacrylate) (weight average molecule! 3) .4X
IO') (An electrophotographic photoreceptor was produced in the same manner as in Example 8 except that 332 g of resin (B-2) was used.
When each characteristic was measured in the same manner as in Example 1, the surface smoothness of the photoconductive layer of each photoreceptor was 100 (see/cc), which was smooth. Lo; -570V, D. R. R. ．．
87χ+EI/I.

29 (erg/c4), (30°C, 80%R
The image quality in l1) was also good. Furthermore,
Even when printed as an offset master master plate, it was possible to print more than 10,000 sheets. Examples 10 to 15 In Synthesis Example 9 of the resin (A) of the present invention, 4 g of each of the mercapto compounds (chain transfer agents) shown in Table 4 were used in place of 4 g of thioglycolic acid. In the same manner, each resin (A) was produced, and all of the photoreceptors of the present invention exhibited excellent properties. In addition, when printed as an offset master original plate, more than 10,000 prints were obtained.

Examples 16 to 25 (Synthesis of Resin A-16) A 1N compound of 60 g of 26-dichlorophenyl methacrylate, 40 g of macroheptanomer (N-9), 2 g of thioglycolic acid, 150 g of toluene, and 50 g of ethanol was heated under a nitrogen stream. It was heated to a temperature of 80°C. ^． C. 3 g of V was added and reacted for 4 hours, and then A, C. V1. Add Og and 4
Time reacted. The weight average molecular weight of the obtained copolymer was 8
．． Each of these copolymers was used in place of 8 g of resin (a-8) and processed under the same conditions as in Example 8 to produce each photosensitive material. (Preparation of photoreceptor) ) 9 g (as solid content) of the above resin (A-16),
31g each of resin (C) shown in Table 5 below, hebutamethine cyanine dye (■) shown by the following structural formula 0.02
A mixture of 0.0 g, 0.15 g of phthalic anhydride, and 300 g of toluene was boiled in a ball mill for 2 hours to prepare a photoreceptive layer-forming product. An electrophotographic photoreceptor was produced in the same manner as in Example 1. Table 5' GOOf+ The numbers in the table are weight composition ratios (cyanine dye (■)) Characteristics were measured. However, a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength: 830 nm) was used as a light source. The results are shown in Table-6.

Table 6 Examples 26 to 37 6 g of resin (A-17) having the following structure, 34 g each of resin (D) of Table 7 below, and the above cyanine dye (1 1
0.018g, maleic anhydride 0.15g, zinc oxide 2
A photosensitive layer-forming product was prepared by dispersing a mixture of 00g of 00g and 300g of toluene in a ball mill for 2 hours. An electrophotographic photoreceptor was produced in the same manner as in Example 1. Resin (A
-17) Mw 8.5
Even under the harsh conditions of 0% R11), it provided clear images with no ground force blur or skipped fine lines. Further, even after making a plate in the same manner as in Example 1 and printing it as an off-cent master original plate, even after printing 10,000 copies, a print with clear image quality and no staining was obtained. Examples 38 to 43 and Comparative Example B 7.5 g of resin (A-18) with the following structure, Table 8 below
32.5g each of resins CB) to (D), 20g of zinc oxide
0g, uranine 0.02g, rose bengal 0.04g
, 0.03 g of bromophenol blue, 0.20 g of phthalic anhydride, and 300 g of toluene. A photosensitive layer-forming product was prepared by boiling the mixture in a ball mill for 2 hours, and this was applied to electrically conductive treated paper using a wire bar so that the dry adhesion amount was 22 g/rrr, and then heated at 110"C for 1 hour. It was dried for 2 minutes at 20°C and 65% Rl1 in the dark.
Each electrophotographic photoreceptor was prepared by leaving it for 4 hours. Resin (A-18) Mw 6.5xlO' Comparative Example B In Example 38, binder resin (A-18) 7.5 g
Example 38 except that 40 g of the resin (P-1) was used as the binder resin instead of 32.5 g of the resin CB).
An electrophotographic photoreceptor was produced in the same manner as described above.

Note 8) Electrostatic properties: In a dark room at a temperature of 20°C and 65% RH, each photosensitive material was subjected to corona discharge at 6 kV for 20 seconds using a paper analyzer (Paper Analyzer SP-428 model manufactured by Kawaguchi II Machine@). After that, leave it for 10 seconds, and at this time the surface potential ν
1. was measured. Then, the potential V after being left undisturbed for 60 seconds in the dark. and the potential retention after dark decaying for 60 seconds, i.e. dark decay retention rate (1) RR (χ)]
was calculated as (νto/V+o)XIOO(X)te. or,
After the surface of the photoconductive layer is charged to -400V by corona discharge, the surface of the photoconductive layer is irradiated with visible light at an illuminance of 2.0 lux, and the time required for the surface potential (L.) to attenuate to 1/10. From this, calculate the exposure amount E + y lo (Lunox seconds). The original offset plate for printing was made under the following conditions. After each luminescent material was left for one day and night under the following environmental conditions, it was subjected to fully automatic plate making jIJ. EshiP~404V C. A copy image (fogging, image quality) obtained by plate making using ELP-T (manufactured by Fuji Photo Film ■) as a toner was visually evaluated. The environmental conditions during imaging were 20°C 65% Rl1 (1
) and 30°C and 80% Rll (II).

Each photoreceptor of the present invention and Comparative Example B are examples in which the spectral brightening dyes are replaced with three types of dyes that brighten in the visible light range. In the case of the dyes used here, even in Comparative Example B, in which a conventional random copolymer was used as the binder resin, the electrophotographic properties were satisfactory, but when printed using it as an offset master original plate, , the desensitization treatment of the non-image area was not sufficient, and scumming occurred from the beginning of printing.

No such phenomenon was observed in each of the photosensitive materials of the present invention, and 80%
Printed matter with clear image quality of 0.00 or higher and no blurring was obtained.

(Effects of the Invention) According to the present invention, an electrophotographic photoreceptor having excellent static Ti properties and mechanical strength can be obtained.

Claims (4)

[Claims] (1) In an electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductor and a binder resin, the binder resin has a weight average molecular weight of 1× represented by the following general formula (I).
Contains at least one macromonomer of 10^3 to 2 x 10^4 as a polymerization component, and -PO_3H_2 group, -SO_3H group, -CO
There are OH groups and ▲mathematical formulas, chemical formulas, tables, etc.▼{R_1
represents a hydrocarbon group or -OR_2 (R_2 represents a hydrocarbon group) group} contains at least one graft copolymer (resin [A]) formed by bonding at least one acidic group selected from An electrophotographic photoreceptor characterized by: General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In formula (I), a_1 and a_2 may be the same or different, and each represents a hydrogen atom, a halogen atom, a cyano group, or a carbon number of 1 to 8. It represents a hydrocarbon group, -COO-Z, or -COO-Z via a hydrocarbon group having 1 to 8 carbon atoms (Z represents a hydrocarbon group having 1 to 18 carbon atoms). X is -COO-, -OCO-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼ (l_1 and l_2 indicate integers from 1 to 3), -CO-, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (P_1
represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms)
, -CONHCONH-, -CONHCOO-, -O-
, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or -SO_2-
represents. Y represents a group connecting X and -O-. [ ] represents a repeating unit, and represents an integer from 1 to 3. When n is 2 or more, W in [ ] represents a group different from at least the adjacent W in [ ]. W has ▲mathematical formula, chemical formula, table, etc.▼or ▲mathematical formula,
There are chemical formulas, tables, etc. ▼ (r_1 and r_2 may be the same or different and each represents a hydrogen atom or an alkyl group) R represents a hydrogen atom or a hydrocarbon group. (2) The resin [A] has a weight average molecular weight of 1 x 10^3 to 2 x 10^4, and the binder resin further includes the following resin [
The electrophotographic photoreceptor according to claim (1), characterized in that it contains B]. Resin [B]; having a weight average molecular weight of 5 x 10^4 to 5 x 10^5,
and -PO_3H_2 group, -SO_3H group, -CO_2
Resin that does not contain H groups, ▲numerical formulas, chemical formulas, tables, etc.▼ (R_1 represents the same content as above) groups, and basic groups. (3) The resin [A] has a weight average molecular weight of 1 x 10^3 to 2 x 10^4, and the binder resin further has the following resin [
The electrophotographic photoreceptor according to claim (1), characterized in that it contains C]. Resin [C]; having a weight average molecular weight of 5 x 10^4 to 5 x 10^5,
A resin containing 0.1 to 15% by weight of a copolymer component containing at least one functional group selected from an OH group and a basic group. (4) The resin [A] has a weight average molecular weight of 1 x 10^3 to 2 x 10^4, and the binder resin further has the following resin [
D] The electrophotographic photoreceptor according to claim (1). Resin [D]; has a weight average molecular weight of 5 x 10^4 to 5 x 10^5,
and 5 of the acidic group content contained in the resin [A] used in combination.
-PO_3H_2 group, -SO_, which has a pKa larger than the pKa of the acidic group contained in the resin or resin [A] containing a copolymerization component containing an acidic group content of 0% or less
A resin containing a copolymer component containing at least one type of acidic group selected from 3H group, -COOH group, and ▼ mathematical formula, chemical formula, table, etc. ▼ (R_3 represents a hydrocarbon group) group.