JP2584283B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor, and more particularly, to an electrophotographic photosensitive member,
The present invention relates to an electrophotographic photosensitive member having excellent moisture resistance and durability.

(Prior Art) An electrophotographic photosensitive member has various configurations in order to obtain predetermined characteristics or according to the type of an applied electrophotographic process.

Representative electrophotographic photoreceptors include a photoreceptor having a photoconductive layer formed on a support and a photoreceptor having an insulating layer on the surface, and are widely used. A photoreceptor composed of a support and at least one photoconductive layer is used for image formation by the most common electrophotographic processes, ie, charging, image exposure and development, and, if necessary, transfer.

Further, a method using an electrophotographic photosensitive member as an offset original plate for direct plate making has been widely used.

The binder used to form the photoconductive layer of the electrophotographic photoreceptor has excellent film forming properties of itself and the ability to disperse the photoconductive powder in the binder, and the formed recording material layer Has good adhesion to the substrate, and 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. Therefore, it is necessary to provide various electrostatic characteristics such as the necessity of maintaining these characteristics stably and excellent imaging performance.

For example, silicone resins (Japanese Patent Publication No. 34-6670), styrene-butadiene resins (Japanese Patent Publication No. 35-1960), alkyd resins, maleic acid resins,
Polyamide (JP-B-35-11219), vinyl acetate resin (JP-B-41-2425), vinyl acetate copolymer (JP-B-41
No. 2426), an acrylic resin (Japanese Patent Publication No. 35-11216), and an acrylate copolymer (for example, Japanese Patent Publication No. 35-11219).
Nos. JP-B-36-8510, JP-B-41-13946, etc.) are known.

However, in an electrophotographic photosensitive material using these resins, 1) the affinity with the photoconductive powder is insufficient, and the dispersibility of the coating liquid is poor. 2) Poor chargeability of photoconductive layer 3) Poor quality of image part of copied image (especially halftone dot reproducibility / resolution) 4) Suitable for environment (for example, high temperature, high humidity, low temperature, low humidity) when copying image is created The image quality is easily affected,
5) The film strength and adhesiveness of the photosensitive layer are not sufficient, especially when used as an offset master,
One of the problems is that the photosensitive layer is detached and the number of printed sheets cannot be increased.

Various methods have been proposed as methods for improving the electrostatic properties of the photoconductive layer. One of the methods is, for example, a compound containing a carboxyl group or a nitro group in an aromatic ring or a furan ring, or an anhydride of a dicarboxylic acid. And JP-B-42-6878 and JP-B-45-3073. However, even the photosensitive materials improved by these methods do not have sufficient electrostatic characteristics, and a material having particularly excellent light attenuation characteristics has not been obtained. Therefore, in order to improve the sensitivity shortage of this photosensitive material,
Conventionally, a method of adding a large amount of a sensitizing dye to a photoconductive layer has been adopted.However, the light-sensitive material produced by such a method significantly deteriorates whiteness and causes deterioration in quality as a recording medium, In some cases, the dark decay of the photosensitive material deteriorates,
There is a problem that a sufficient copied image cannot be obtained.

On the other hand, Japanese Patent Application Laid-Open No. 60-10254 discloses a method in which the average molecular weight of the resin is adjusted and used as the binder resin used in the photoconductive layer. That is, by using an acrylic resin having an acid value of 4 to 50 and a component having an average molecular weight of 10 ³ to 10 ⁴ and a component having a distribution of 10 ⁴ to 2 × 10 ⁵ , the electrostatic properties (particularly,
A technique for improving the reproducibility of the PPC photoreceptor and the moisture resistance is described.

Furthermore, research on average printing masters using an electrophotographic photosensitive member has been earnestly conducted, and a binder resin for a photoconductive layer that has both electrostatic characteristics as an electrophotographic photosensitive member and printing characteristics as a printing original plate has been obtained. For example, in Japanese Patent Publication No. 50-31011,
Copolymerized with (meth) acrylate monomer and other monomers in the presence of fumaric acid, Tg 10-80 at Mw 1.8-10 × 10 ⁴
C. and a copolymer comprising a (meth) acrylate monomer and a monomer other than fumaric acid. JP-A-53-54027 discloses that a carboxylic acid group is formed by forming at least an atom from an ester bond. Those using a terpolymer containing a (meth) acrylic ester having a substituent which is located at a distance of several sevens, and those disclosed in JP-A-54-20735 and JP-A-57-20254.
No. 4 uses a quaternary or pentameric copolymer containing acrylic acid and hydroxyethyl (meth) acrylate,
JP-A-58-68046 discloses a method using a terpolymer containing a (meth) acrylate ester having an alkyl group having 6 to 12 carbon atoms as a substituent and a carboxylic acid-containing vinyl monomer. It is described that it is effective in improving the desensitizing property of the layer.

(Problems to be Solved by the Invention) However, even if the above-mentioned resin is said to be effective for the electrostatic property, the moisture resistance property and the durability, particularly when it is actually evaluated, the chargeability and the dark charge retention property are particularly high. However, there are problems with the electrostatic characteristics of photosensitivity, the smoothness of the photoconductive layer, and the like, which have not been practically satisfactory.

Further, even in the case of a binder resin developed as an electrophotographic lithographic printing plate precursor, when actually evaluated, there were problems with the above-described electrostatic characteristics, background contamination of printed matter, and the like.

The present invention is to improve the problems of the conventional electrophotographic photoreceptor as described above.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-quality electrophotographic photoreceptor having improved electrostatic characteristics (particularly dark charge retention and photosensitivity) and reproducing a copied image faithful to an original image.

Another object of the present invention is to provide an electrophotographic photoreceptor having a clear and high-quality image even when the environment at the time of forming a copy image fluctuates such as low temperature and low humidity or high temperature and high humidity.

Another object of the present invention is to provide an electrophotographic lithographic printing plate precursor having excellent electrostatic properties (particularly dark charge retention and light sensitivity),
An object of the present invention is to provide a lithographic printing original plate that reproduces a copied image faithful to an original image and does not generate not only a uniform background stain but also a dot-like background stain on a printed matter.

(Means for Solving the Problems) The above object is achieved by an electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductive material and a binder resin.
It has been found that this problem can be solved by an electrophotographic photoreceptor characterized in that the binder resin contains at least one of each of the following resins [A] and [B].

(I) Resin [A] having a weight average molecular weight of 1 × 10 ³ to 1 × 10 ⁴ and -PO
₃ H ₂ group, -COOH group, 0.05 copolymerization component containing at least one polar group selected from -SO ₃ H group and -OH group
Resin containing 20% by weight.

(Ii) Resin [B] A polymer containing a repeating unit represented by the following general formula (I), a part of which is cross-linked, and at least one terminal of at least one polymer main chain has -PO ₃ H ₂ group, -SO ₃ H group, at least one resin formed by combining a polar group selected from -COOH group and -OH group.

General formula (I) Wherein, X is -COO -, - OCO -, - CH 2 OCO -, - CH 2 COO
-, - O-or -SO ₂ - represent.

 Y represents a hydrocarbon group having 1 to 22 carbon atoms.

a ₁ and a ₂ 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 hydrocarbon group having 1 to 8 carbon atoms. -Z-COO-Z (Z represents a hydrocarbon group having 1 to 18 carbon atoms).

The binder resin used in the present invention is a low molecular weight resin [A] containing a specific polar group and a partially crosslinked high molecular weight resin having the polar group bonded only to at least one end of the polymer main chain. At least the resin [B].

It is more preferably a polar group contained in the resin (A) -PO ₃ H ₂ groups include -COOH group and -SO ₃ H groups.

The proportion of the copolymer component containing the polar group is determined by the resin [A]
0.05 to 20% by weight, more preferably 0.5 to 10% by weight.
% By weight. The weight average molecular weight of the resin [A] is 1 × 10 ³
１1 × 10 ⁴ , more preferably 3 × 10 ³ -9 × 10 ³
It is.

The glass transition point of the resin (A) is preferably -10 ° C to 100 ° C.
C, more preferably in the range of -5C to 80C.

The weight average molecular weight of the resin [B] is from 5 × 10 ⁴ to 8 × 10 ⁵ , and more preferably from 8 × 10 ^{4 to} 6 × 10 ⁵ .

The glass transition point of the resin [B] is preferably 0 ° C to 120 ° C.
And more preferably from 10 ° C to 95 ° C.

In the present invention, since the polar group contained in the resin [A] is adsorbed to the stoichiometric defect of the inorganic photoconductor and is a low molecular weight substance, the covering property of the surface of the photoconductor is reduced. By improving the value, the trapping of the photoconductor is compensated and the humidity characteristics are improved, while the photoconductor is sufficiently dispersed and aggregation is suppressed. The resin [B] sufficiently enhances the mechanical strength of the photoconductive layer, which is insufficient with the resin [A] alone.

When the content of the polar group in the resin [A] is less than 0.05% by weight, the initial potential is too low to obtain a sufficient image density. On the other hand, when the content of the polar group is more than 20% by weight, the dispersibility is reduced, the film smoothness and the high humidity property of the electrophotographic properties are reduced, and the background fouling is increased when used as an offset master. Therefore, it is not preferable. When the weight average molecular weight of the resin [A] is less than 1 × 10 ³ , the viscosity of the dispersion containing the inorganic photoconductor becomes small, making uniform coating difficult, and even if a photoreceptor is obtained, the electrophotographic properties will be poor. Getting worse. On the other hand, when the weight average molecular weight exceeds 1 × 10 ⁴ , the electrophotographic properties (particularly, DRR and E _1/10 ) deteriorate.

The resin [B] reinforces the mechanical strength of the photoconductive layer without impairing the high performance of the electrophotographic properties due to the use of the resin [A], but has a weight average molecular weight of the resin [B]. Is less than 5 × 10 ⁴ , the film strength becomes insufficient. On the other hand, if the weight average molecular weight exceeds 8 × 10 ⁵ , the solubility of the organic solvent becomes almost negligible, and it becomes practically unusable.

Since the resin [B] of the present invention is a copolymer which is appropriately crosslinked and has a polar group bonded only to one end of the main chain, the interaction between the polymer chains and the polar group and the photoconductive It is considered that the weak interaction with the particles and the like act synergistically to achieve remarkably excellent performance in electrophotographic characteristics and film strength.

Further, in the present invention, the smoothness of the photoconductor surface becomes smooth. When a photoconductor having a rough surface of the photoconductive layer is used as the electrophotographic lithographic printing plate precursor, the dispersion state of the inorganic particles as the photoconductor and the binder resin is not appropriate, and the photoconductive layer is in a state where the aggregates are present. Since the layer is formed, even if the desensitizing treatment with the desensitizing solution is performed, the non-image area is not uniformly and sufficiently hydrophilized, causing the printing ink to adhere during printing, and as a result, the non-image The part will be soiled. Furthermore, even when only the low molecular weight resin [A] in the present invention is used as the binder resin, the photoconductor and the binder resin are sufficiently adsorbed and the surface of the particles can be covered, so that the photoconductive layer has a smooth surface. Although good image quality without stains and background can be obtained in terms of properties and electrostatic characteristics, the film strength is not yet sufficient, and satisfactory results in durability cannot be obtained.

When the resin of the present invention is used, the interaction between the adsorption and coating of the inorganic photoconductor and the binder resin is properly performed, and the film strength of the photoconductive layer is maintained.

The resin [A] may be any of conventionally known resins as long as it has the above-mentioned physical properties. For example, a polyester resin,
Modified epoxy resin, silicone resin, polycarbonate resin, vinyl alkanoate resin, modified polyamide resin, phenol resin, fatty acid alkyd resin, acrylic resin and the like are used.

More specifically, an example of the resin [A] is a (meth) acrylic copolymer containing a monomer represented by the following general formula (II) as a copolymer component and containing a total amount of 30% by weight or more. Can be mentioned.

General formula (II) In the general formula (I), b ₁ is a hydrogen atom or carbon atom 1
Represents to 4 alkyl groups, b ₂ represents a hydrogen atom, a halogen atom (e.g. chlorine atom, bromo atom), a cyano group or an alkyl group having 1 to 4 carbon atoms. R 'has 1 carbon atom
To 18 optionally substituted alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl,
Hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, 2-methoxyethyl, 2
-Ethoxyethyl group and the like), an optionally substituted alkenyl group having 2 to 18 carbon atoms (for example, a vinyl group, an allyl group,
Isopropenyl group, butenyl group, hexenyl group, heptenyl group, octenyl group and the like, and optionally substituted aralkyl group having 7 to 12 carbon atoms (for example, benzyl group, phenethyl group, methoxybenzyl group, ethoxybenzyl group, methylbenzyl) A substituted or unsubstituted cycloalkyl group having 5 to 8 carbon atoms (eg, cyclopentyl group, cyclohexyl group, cycloheptyl group, etc.), an optionally substituted aryl group (eg, phenyl group, tolyl group) , A xylyl group, a mesityl group, a naphthyl group, a methoxyphenyl group, an ethoxyphenyl group, a chlorophenyl group, a dichlorophenyl group, etc.).

The “copolymer component containing a polar group” in the resin [A] of the present invention may be any vinyl compound containing the polar group which can be copolymerized with the monomer of the general formula (II). . For example, it is described in “Polymer Data Handbook [Basic Edition]” edited by The Society of Polymer Science, Baifukan (1986). Specifically, acrylic acid, α- and / or β-substituted acrylic acid (for example, α-acetoxy form, α-acetoxymeter form, α- (2-amino) ethyl form, α-chloro form, α-form
-Bromo, α-fluoro, α-tributylsilyl, α-cyano, β-chloro, β-bromo, α-
Chloro-β-methoxy, α, β-dichloro, etc.), methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid semiamides, crotonic acid, 2-alkenylcarboxylic acids (eg, 2-pentenoic acid, -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, vinylbenzene Carboxylic acid, vinylbenzenesulfonic acid, vinylsulfonic acid, vinylphosphonic acid, half-ester derivatives of vinyl groups or allyl groups of dicarboxylic acids, and the carboxylic acid or sulfonic acid ester derivatives and amide derivatives in the substituents thereof. Examples include compounds containing a polar group.

Further, the resin [A] of the present invention may contain, as a copolymerization component, other monomers other than the above-mentioned monomer of the general formula (II) and the monomer containing the polar group. .

For example, α-olefins, vinyl alkanoate or allyl esters, acrylonitrile, methacrylonitrile, vinyl ethers, acrylamides, methacrylamides, styrenes, heterocyclic vinyls (eg, vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylthiophene) , Vinyl imidazoline, vinyl pyrazole, vinyl dioxane, vinyl quinoline, vinyl thiazole, vinyl oxazine, etc.).

On the other hand, the resin [B] of the present invention is a polymer containing at least one kind of the repeating unit represented by the general formula (I), which is partially cross-linked, and has at least one end of one main chain. only a -PO ₃ H ₂ group, -SO ₃ H groups, formed by combining at least one polar group selected from -COOH group and -OH group polymers.

In the repeating unit represented by the formula (I), the hydrocarbon group may be substituted.

In the general formula (I), X is preferably -COO-, -O
_{CO -, - CH 2 OCO -} , - CH 2 COO- or represents -O-, more preferably -COO -, - represents a CH ₂ COO- or -O-.

Y preferably represents an optionally substituted hydrocarbon group having 1 to 18 carbon atoms. As the substituent, any substituent may be used as long as it is a substituent other than a polar group bonded to one end of the polymer main chain. For example, a halogen atom (for example, a fluorine atom,
A chlorine atom, a bromine atom, _{etc.), - O-Y 1 -} , - COO-Y 2, -O
_{CO-Y 3 (Y 1 ~Y} 3 represents an alkyl group having 6 to 22 carbon atoms, e.g., hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, and the like) substituent such as Is mentioned. Preferred hydrocarbon groups include
An alkyl group having 1 to 18 carbon atoms which may be substituted (for example,
Methyl, ethyl, propyl, butyl, heptyl, hexyl, octyl, decyl, dodecyl,
Hexadecyl group, octadecyl group, 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3
-Bromopropyl group and the like, and an optionally substituted alkenyl group having 4 to 18 carbon atoms (eg, 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group) , A 1-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, a 4-methyl-2-hexenyl group, etc., and an optionally substituted aralkyl group having 7 to 12 carbon atoms (for example, benzyl group, phenethyl group, 3 -Phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group,
Chlorobenzyl group, bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), having 5 to 8 carbon atoms
An optionally substituted alicyclic group (e.g., cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl group, etc.) or an optionally substituted aromatic group having 6 to 12 carbon atoms (e.g., phenyl group, Naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl, dichlorophenyl, bromophenyl Group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecyloylamidophenyl group, etc.).

a ₁ and a ₂ may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, an alkyl group having 1 to 3 carbon atoms, —COO -Z or -CH ₂ COO-Z (Z preferably represents an aliphatic group having 1 to 22 carbon atoms). More preferably, a ₁ and a ₂ may be the same or different from each other, and include a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (for example, a methyl group,
Ethyl, propyl, etc.), - COO-Z or -CH ₂ COO-
Z (Z more preferably represents an alkyl group or an alkenyl group having 1 to 18 carbon atoms, for example, a methyl group, an ethyl group,
Propyl, butyl, hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, pentenyl, hexenyl, octenyl, decenyl and the like. The alkenyl group may have the same substituent as that represented by Y).

In addition, a polar group that binds to only one terminal of the polymer main chain has a chemical structure that is directly bonded to one terminal of the polymer main chain or that is bonded via an arbitrary linking group.

Examples of the bonding group include a carbon-carbon bond (single bond or double bond), a carbon-heteroatom bond (for example, an oxygen atom, a sulfur atom, a nitrogen atom, and a silicon atom), and a heteroatom-heteroatom bond. It is composed of any combination of atomic groups. For example, [R ₁ and R ₂ represent a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, a hydroxyl group, an alkyl group (eg, a methyl group, an ethyl group, a propyl group, etc.) ], CH = CH, -O-, -S-, -COO -, - SO ₂ -, -NHCOO-, -NHCONH-, [Where R ₃ is a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a benzyl group, a phenethyl group, a phenyl group, a tolyl group, etc.) ) or -OR ₄ (R ₄ represents a represents the same meaning as the hydrocarbon group of R _3)] and the like.

The resin [B] of the present invention corresponds to a polymer component selected from the repeating units represented by the general formula (I) as a homopolymer component or a repeating unit represented by the general formula (I). It is a polymer which is contained as a copolymer component obtained by copolymerization with another monomer which can be copolymerized with the monomer and partially crosslinked.

As a method for introducing a crosslinked structure into the polymer, a generally known method can be used. That is, in the polymerization reaction of the monomer, there are a method of polymerizing in the presence of a polyfunctional monomer and a method of including a functional group which advances a crosslinking reaction in a polymer and crosslinking by a polymer reaction.

The resin [B] of the present invention has a simple production method (for example, a long reaction time is required, the reaction is not quantitative, and there are few problems such as contamination with impurities due to the use of a reaction promoting aid). From, a functional group that undergoes a self-crosslinking reaction: -CONHCH ₂ O
A crosslinking reaction by R ₅ (R ₅ represents a hydrogen atom or an alkyl group) or by polymerization is effective.

In the case of a polymerization-reactive group, preferably, a method of crosslinking a polymer chain by polymerizing a monomer having two or more polymerizable functional groups together with the monomer of the above formula (I) is preferable. .

Specific examples of the polymerizable functional group include CH ₂ CHCH— and CH ₂ CHCH—
CH ₂ −, CH ₂ CH ₂ = CH-CONH-, _{CH 2 = CH-NHCO-, CH} 2 = CH-CH 2 -NHCO-, CH 2 = CH-SO
_2- , CH ₂ CHCH—CO—, CH ₂ CHCH—O—, CH ₂ CHCH—S— and the like can be mentioned, and the monomer having two or more polymerizable functional groups is A monomer having two or more of the same or different polymerizable functional groups may be used.

Specific examples of the monomer having two or more polymerizable functional groups include, for example, styrene derivatives such as divinylbenzene and trivinylbenzene as monomers having the same polymerizable functional group:
Polyhydric alcohols (eg, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol # 200, # 400, # 600, 1,3-butylene glycol, neopentyl glycol, dipropylene glycol, polypropylene glycol, trimethylolpropane, trimethylol Ethane, pentaerythritol, etc.) or polyhydroxyphenol (eg, hydroquinone, resorcin, catechol and derivatives thereof)
Methacrylic acid, acrylic acid or crotonic acid esters, vinyl ethers or allyl ethers: dibasic acids (eg, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, itaconic acid, etc.) Vinyl esters, allyl esters, vinylamides or allylamides: polyamines (eg, ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, etc.) and carboxylic acids containing vinyl groups (eg, methacrylic acid, acrylic Acid, crotonic acid, allyl acetic acid, etc.).

Further, as a monomer having a different polymerizable functional group, for example, a carboxylic acid containing a vinyl group (for example, methacrylic acid, acrylic acid, methacryloyl acetic acid, acryloyl acetic acid, methacryloyl propionic acid, acryloyl propionic acid, itaconiloyl acetic acid, Reactant of niloylpropionic acid, carboxylic anhydride and alcohol or amine (eg, allyloxycarbonylpropionic acid, allyloxycarbonylacetic acid, 2-allyloxycarbonylbenzoic acid, allylaminocarbonylpropionic acid, etc.)
Ester derivatives or amide derivatives containing a vinyl group (e.g., vinyl methacrylate, vinyl acrylate, vinyl itaconate, allyl methacrylate, allyl acrylate, allyl itaconate, vinyl methacryloyl acetate, vinyl methacryloyl propionate, methacryloyl Allyl propionate, vinyloxycarbonylmethyl methacrylate, vinyloxycarbonylmethyloxycarbonylethylene acrylate, N-allylacrylamide, N-allylmethacrylamide, N
-Allylitaconamide, allylamide methacryloylpropionate, etc.) or amino alcohols (e.g., aminoethanol, 1-aminopropanol, 1-aminobutanol, 1-aminohexanol, 2-aminobutanol, etc.) and vinyl-containing carboxylic acid Acid condensates and the like.

In the present invention, a partially crosslinked resin [B] is obtained by polymerizing a monomer having two or more polymerizable functional groups using 15% by weight or less, preferably 10% by weight or less of all monomers. ] Can be formed.

The resin (B) of the present invention is soluble in an organic solvent, specifically, a temperature of 25 ° C. with respect to 100 parts by weight of a toluene solvent.
In this case, it is sufficient that the resin [B] dissolves at least 5 parts by weight or more. Further, the resin [B] of the present invention in which a specific polar group is bonded only to at least one terminal of the polymer main chain, is added to the terminal of a living polymer obtained by conventionally known anionic or cationic polymerization. A method of reacting various reagents (method by an ionic polymerization method), a method of radical polymerization using a polymerization initiator and / or a chain transfer agent containing a specific polar group in a molecule (a method by a radical polymerization method), or According to a synthesis method such as a method of converting a polymer having a terminal reactive group obtained by an ionic polymerization method or a radical polymerization method into a specific polar group of the present invention by a polymer reaction, as described above. It can be easily manufactured.

Specifically, P. Dreyfuss, RPQuirk, Encycl.Polym.Sc
Review of i.Eng, 7 : 551 (1987), Yoshiki Chujo, Yuya Yamashita, "Dyes and Chemicals", 30 , 232 (1985), Akira Ueda, Susumu Nagai, "Science and Industry" 60 , 57 (1986), etc. It can be produced by the method described in the cited document or the like.

The polymer of the resin [B] used in the present invention specifically includes a monomer corresponding to the repeating unit represented by the general formula (I), the above-mentioned polyfunctional monomer and the polar group. A method of polymerizing a mixture of the chain transfer agents to be contained with a polymerization initiator (for example, an azobis compound, a peroxide or the like), or a polymerization using the polymerization initiator containing the polar group without using the chain transfer agent. Or a method using a compound containing the polar group as both a chain transfer agent and a polymerization initiator, and further, in the above three methods, as a substituent of the chain transfer agent or the polymerization initiator, an amino group, After the polymerization reaction using a compound containing a halogen atom, an epoxy group, an acid halide group, and the like, a method of introducing the polar group by reacting with a functional group by a polymer reaction, and the like, and the like. Can As the chain transfer agent to be used, for example, a mercapto compound containing the polar group or a substituent capable of being induced to the polar group (for example, thioglycolic acid, thiomalic acid, thiosalicylic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, N- (2-mercaptopropionyl) glycine, 2
-Mercaptonicotinic acid, 3- [N (2-mercaptoethyl) carbamoyl] propionic acid, 3- [N- (2-
Mercaptoethyl) amino] propionic acid, N- (3-
Mercaptopropionyl) alanine, 2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid,
4-mercaptobutanesulfonic acid, 2-mercaptoethanol, 3-mercapto-1,2-propanediol, 1
-Mercapto-2-propanol, 3-mercapto-2
-Butanol, mercaptophenol 2-mercaptoethylamine, 2-mercaptoimidazole, 2-mercapto-3-pyridinol or the like, or an iodoalkyl compound containing the above polar group or substituent (for example, iodoacetic acid, iodopropionic acid, 2-iodo) Ethanol, 2
-Iodoethanesulfonic acid, 3-iodopropanesulfonic acid, etc.). Preferably, a mercapto compound is used.

These chain transfer agents or polymerization initiators are each used in an amount of 0.5 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the total monomers.

In addition, the resin [B] may be used together with a monomer corresponding to the repeating unit represented by the general formula (I) and the above-mentioned polyfunctional monomer, and other monomers other than these (for example, the resin [A ] As the other monomer which may be contained in the above-mentioned) may be contained as a copolymerization component.

Further, in addition to the resins [A] and [B] of the present invention, other resins can be used in combination. Examples of such resins include alkyd resins, polybutyral resins, polyolefins, ethylene-vinyl acetate copolymer, styrene resins, styrene-butadiene resins, acrylate butadiene resins, and vinyl alkanoate resins.

When the other resin exceeds 30% (weight ratio) of the total amount of the binder resin using the resin of the present invention, the effect of the present invention (especially, improvement of electrostatic characteristics) is lost.

The ratio of the amount of the resin [A] and the amount of the resin [B] used in the present invention differs depending on the type, particle size, and surface state of the inorganic photoconductive material used, but generally the ratio of the resin [A] and the resin [B] is different. The ratio used is 5-80 to 95-20 (weight ratio), preferably
It is 15-60 to 85-40 (weight ratio).

Examples of the inorganic photoconductive material used in the present invention include zinc oxide-titanium oxide, zinc sulfide, cadmium sulfide, cadmium carbonate, zinc selenide, cadmium selenide, tellurium selenide, and lead sulfide.

The total amount of the binder resin used for the inorganic photoconductive material is 10 to 100 parts by weight, preferably 15 to 50 parts by weight, based on 100 parts by weight of the photoconductor.

In the present invention, various dyes can be used as spectral sensitizers as needed. For example, Harumi Miyamoto, Hidehiko Takei, Imaging 1973 (No.8), page 12, CJ Young, etc., RCA
Review 15 , 469 (1954), Kohei Kiyota, IEICE Transactions J 63-C (No.2), 97 (1980), Yuji Harasaki et al., Industrial Science Journals 66 78 and 188 (1963), Tadaaki Tani, Carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, and the like, as described in Photographic Society of Japan 35 , 208 (1972), etc.
Examples include xanthene dyes, phthalein dyes, polymethine dyes (eg, oxanol dyes, merocyanine dyes, cyanine dyes, rhodacyanine dyes, styryl dyes, etc.), phthalocyanine dyes (which may contain metals), and the like.

More specifically, those using mainly a carbonium dye, a triphenylmethane dye, a xanthene dye, and a phthalein dye are described in JP-B-51-452,
-90334, JP-A-50-114227, JP-A-53-39130,
JP-A-53-82353, U.S. Pat. No. 3,052,540, U.S. Pat. No. 4,054,450, and JP-A-57-16456 are examples.

Examples of polymethine dyes such as oxanol dyes, merocyanine dyes, cyanine dyes, and rhodacyanine dyes include F.I.
M. Hamer `` The Cyanine Dyes and Related Compounds ''
Can be used, more specifically, more specifically,
U.S. Patent 3,047,384, U.S. Patent 3,110,591, U.S. Patent 3,121,008, U.S. Patent 3,125,447, U.S. Patent 3,128,179, U.S. Patent 3,132,942, U.S. Pat.
622,317, UK Patent 1,226,892, UK Patent 1,309,
No. 274, British Patent No. 1,405,898, JP-B-48-7814, JP-B-55-18892 and the like.

Further, as polymethine dyes for spectrally sensitizing the near infrared to infrared light region having a long wavelength of 700 nm or more, JP-A-47-840, JP-A-47-44180, JP-B-51-41061, and JP-A-51-41061 49−5034
No., JP-A-49-45122, JP-A-57-46245, JP-A-56
No. -35141, JP-A-57-157254, JP-A-61-26044,
JP-A-61-27551, U.S. Pat.No. 3,619,154, U.S. Pat.No.4,175,956, `` Research Disclosure '' 1982, 21
6, pages 117 to 118 and the like. The photoreceptor of the present invention is excellent in that even when various sensitizing dyes are used in combination, the performance is hardly changed by the sensitizing dye. Furthermore, various conventionally known additives for an electrophotographic photosensitive layer such as a chemical sensitizer can be used in combination, if necessary.
For example, the review mentioned above: Imaging 1973 (No. 8) No. 12
"Recent development and commercialization of photoconductive materials and photoreceptors", e.g., electron accepting compounds (e.g., halogen, benzoquinone, chloranil, acid anhydride, organic carboxylic acid, etc.) and Hiroshi Komon, which are described in pages and other reviews. Chapters 4 to 6: Polyarylalkane compounds, hindered phenol compounds, P-phenylenediamine compounds, and the like, which are referred to in the review articles of Japan Science Information Co., Ltd., Publishing Division (1986).

The amounts of these various additives are not particularly limited, but are usually 0.0001 to 2.0 parts by weight based on 100 parts by weight of the photoconductor.

The thickness of the photoconductive layer is preferably from 1 to 100 µ, particularly preferably from 10 to 50 µ.

When a photoconductive layer is used as the charge generation layer of the photoreceptor in which the charge generation layer and the charge transport layer are stacked, the thickness of the charge generation layer is preferably 0.01 to 1 μm, particularly preferably 0.05 to 0.5 μm.

In some cases, an insulating layer is provided for the main purpose of protecting the photoreceptor, improving durability, and improving dark attenuation characteristics. At this time, the insulating layer is set relatively thin, and the insulating layer provided when the photosensitive member is used in a specific electrophotographic process is set relatively thick.

In the latter case, the thickness of the insulating layer is between 5 and 70 μm, especially 10
Set to ~ 50μ.

Examples of the charge transport material of the laminated photoreceptor include polyvinyl carbazole, oxazole dyes, pyrazoline dyes, and triphenylmethane dyes. The thickness of the charge transport layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm.

As the resin used for forming the insulating layer or the charge transport layer, typical ones are polystyrene resin, polyester resin, cellulose resin, polyether resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-copolymer resin, A thermoplastic resin such as a polyacryl resin, a polyolefin resin, a urethane resin, an epoxy resin, a melamine resin, or a silicone resin and a curable resin are appropriately used.

The photoconductive layer according to the present invention can be provided on a conventionally known support. Generally, the support of the electrophotographic photosensitive layer is preferably conductive. As the conductive support, a substrate such as a metal, paper, plastic sheet or the like is impregnated with a low-resistance substance in the same manner as in the related art. A substrate that has been subjected to a conductive treatment, for example, by applying a conductivity to the back surface of the substrate (the surface opposite to the surface on which the photosensitive layer is provided), and further coated with at least one layer for the purpose of preventing curling and the like. A substrate provided with a water-resistant adhesive layer on its surface, a substrate provided with at least one or more pre-coat layers as required on the surface layer of the support, and a substrate-conductive plastic on which Al or the like is deposited is laminated on paper. Can be used.

Specifically, as examples of conductive substrates or conductive materials, Yukio Sakamoto, Electrophotography, 14 (No. 1), P2-11 (1975),
Hiroyuki Moriga, “Chemistry of Introductory Special Papers” Polymer Publishing Association (197
5), MFHoover, J. Macromol. Sci. Chem. A-4 (6), No.
Those described on pages 1327 to 1417 (1970) and the like are used.

(Examples) Examples of the present invention will be described below, but the contents of the present invention are not limited thereto.

Synthesis Example 1: Resin [A] -1 A mixed solution of 95 g of ethyl methacrylate, 5 g of acrylic acid and 200 g of toluene was heated to 90 ° C. under a nitrogen stream, and then heated to 2,2′-azobis (2,4-dimethylvalero). Nitrile)
6 g was added and reacted for 10 hours. Obtained copolymer [A]
The weight average molecular weight of -1 was 7,800, and the glass transition point was 45 ° C.

Synthesis Example 2: Comparative resin (R) -1 After heating a mixed solution of 94 g of ethyl methacrylate, 6 g of acrylic acid, and 200 g of toluene to a temperature of 70 ° C under a nitrogen stream, 0.5 g of azobisisobutyronitrile was added, The reaction was performed for 10 hours. The weight average molecular weight of the obtained copolymer [R] -1 was 60,000.

Synthesis Example 3: Comparative resin [R] -2 After heating a mixed solution of ethyl methacrylate 97 g, acrylic acid 3 g and toluene 200 g to a temperature of 70 ° C. under a nitrogen stream, 0.5 g of azobisisobutyronitrile was added, The reaction was performed for 10 hours. The weight average molecular weight of the obtained copolymer [R] -2 was 65,000.

Production Example 1 of Resin [B] 1: Resin [B] -1 100 g of ethyl methacrylate, 1.5 g of thioglycolic acid,
A mixed solution of 2.5 g of divinylbenzene and 200 g of toluene was heated to 80 ° C. while stirring under a nitrogen stream. 2,2'-azobis (cyclohexane-1-carbonitrile) (abbreviation)
(ACHN) 0.8 g was added and reacted for 4 hours.
After 2 hours, 0.2 g of ACHN was added, and the mixture was reacted for 2 hours. After cooling, the mixed solution was reprecipitated in methanol 1.5, and the white powder was collected by filtration and dried to obtain 88 g of a powder.
The weight average molecular weight of the obtained polymer [B] -1 is 1.5 × 10 ⁵
It was.

Production Examples 2 to 14 of Resin [B]: Resin [B] -2 to -14 Production Example of Resin [B] except that in Preparation Example 1, the monomers shown in Table 1 below were used instead of 100 g of ethyl methacrylate. The same operation as in Example 1 was carried out to produce each resin [B].

Production Examples 15 to 27 of Resin [B]: Resin [B] -15 to -27 In Production Example 1 of Resin [B], instead of 2.5 g of divinylbenzene, which is a polyfunctional monomer for crosslinking, the following table was used. -2
Resin [B] was produced in the same manner as in Production Example 1 except that the polyfunctional monomer or oligomer was used.

Production Example 28 of Resin (B): Resin (B) -28 88.5 g of benzyl methacrylate, 1.5 g of thiomalic acid,
2.5 g divinylbenzene, 150 g toluene and 50 ethanol
g of the mixed solution was heated to 70 ° C. under a nitrogen stream. 2,2 ′
-Azobis (isobutyronitrile) (abbreviations A, I, B, N,) 1.
0 g was added and reacted for 5 hours, and then A, I, B, N and 0.3 g were added and reacted for 3 hours. Further, A, I, B and N and 0.2 g were added and reacted for 3 hours. After cooling, the precipitate was reprecipitated in methanol 2, and the white powder was collected by filtration and dried. The obtained polymer [B] -28 had a yield of 80 g and a polymer w of 1.3 × 10 ⁵ .

Production Examples 29 to 34 of Resin (B): Resins (B) -29 to -34 In the above Production Example 28, except that 1.5 g of thiomalic acid was replaced with 1.5 g of each mercapto compound in Table 3 below, Resin [B] was produced in the same manner as in Production Example 23.

Production Example 35 of Resin [B]: Resin [B] -35 A mixed solution of 100 g of ethyl methacrylate, 0.5 g of ethylene glycol dimethacrylate, 150 g of toluene and 30 g of isopropyl alcohol was heated to a temperature of 80 ° C. under a nitrogen stream. 2,2'-azobis (2-cyanovaleric acid) (abbreviation AC
V.) 1.5 g was added and reacted for 5 hours, and 0.5 g of ACV was further added and reacted for 3 hours. The weight average molecular weight of the obtained polymer [B] -35 was 2.2 × 10 ⁵ .

Production Example 36 to 41 of Resin (B): Resin [B] -36 to -41 In Production Example 35, instead of 100 g of ethyl methacrylate and 0.5 g of ethylene glycol dimethacrylate, each of the compounds described in Table 4 below was used. Except having been changed, each resin [B] was produced in the same manner as in Production Example 35.

Example 1 8 g (as solid content) of resin [A] -1 produced in Synthesis Example 1 and resin [B]-produced in Production Example 1 of Resin [B]
1 (as solid content), a mixture of zinc oxide 200 g, rose bengal 0.05 g, phthalic anhydride 0.05 g and toluene 300 g was dispersed in a ball mill for 2 hours to prepare a photosensitive layer-forming product, 18g /
It was coated with a wire bar so as to obtain m ² , dried at 110 ° C. for 1 minute, and then left in a dark place at 20 ° C. and 65% RH for 24 hours to prepare an electrophotographic photosensitive material.

Comparative Example A Resin [A]-used as binder resin in Example 1
Instead of 1 and [B] -1, only resin [A] -1 was used for 40
An electrophotographic photosensitive material A was produced in the same manner as in Example 1 except that g (as the solid content) was used.

Comparative Example B An electrophotographic photosensitive material B was produced in the same manner as in Example 1, except that only 40 g (as a solid content) of the resin [B] -1 produced in Production Example 1 of the resin [B] was used as the binder resin. did.

Comparative Example C As a binder resin, only resin [R] -3 having the following structure was used.
An electrophotographic photosensitive material C was produced in the same manner as in Example 1 except that g was used.

Resin [R] -3 Comparative Example D Resin [B]-used as binder resin in Example 1
Resin [R] -3 used in Comparative Example C instead of 132 g
An electrophotographic photosensitive material D was produced in the same manner as in Example 1 except that the amount was changed to 32 g.

The film properties (surface smoothness), film strength, electrostatic properties, imaging properties, and imaging properties of these photosensitive materials when the environmental conditions were 30 ° C. and 80% RH were examined. Further, when these photosensitive materials are used as masters for offset masters, the photoconductive desensitizing property (expressed by the contact angle of the photoconductive layer with water after the desensitizing treatment) and printability (ground contamination) , Printing durability, etc.).

The image-capturing property and printability were evaluated by using a fully automatic plate making ELP404V (manufactured by Fuji Photo Film Co., Ltd.) using ELP-T as a developer by exposing and developing to form an image and desensitizing liquid ELP-E. A lithographic printing plate obtained by etching with an etching processor was used for examination (a Hamadastar 800SX model manufactured by Hamadastar Co., Ltd. was used as a printing machine).

 The above results are summarized in Table-5.

The embodiments of the evaluation items shown in Table-5 are as follows.

Note 1) Smoothness of photoconductive layer: The obtained photosensitive material was measured for its smoothness (sec / cc) using a Bekk smoothness tester (manufactured by Kumagaya Riko Co., Ltd.) under the condition of an air capacity of 1 cc. It was measured.

Note 2) Mechanical strength of the photoconductive layer: The surface of the obtained photosensitive material was applied to an emery paper (#) with a load of 50 g / cm ² using a Haydon-14 type surface test material (manufactured by Shinto Chemical Co., Ltd.). Abrasion powder was removed 1000 times repeatedly at 1000), and the remaining film ratio (%) was determined from the decrease in the weight of the photosensitive layer to determine the mechanical strength.

Note 3) Electrostatic properties: Paper analyzer (Paper analyzer manufactured by Kawaguchi Electric Co., Ltd.) in a dark room at a temperature of 20 ° C. and 65% H.
After the 20 seconds corona discharge -6kV with SP-428 type), allowed to stand for 10 seconds to measure the surface potential V ₁₀ at this time.
Then, the potential V ₇₀ after standing still in the dark for 60 seconds was measured, and the retention of the potential after dark decay for 60 seconds, that is, the dark decay retention rate [DRR (%)] was (V ₇₀ / V ₁₀ ). × 100 (%).

After the surface of the photoconductive layer is charged to −400 V by corona discharge, the surface of the photoconductive layer is irradiated with visible light having an illuminance of 2.0 lux, and the time required for the surface potential (V ₁₀ ) to decrease to 1/10 is measured. The exposure amount E _1/10 (lux / sec) is calculated from this.

Note 4) Image-capturing properties: Copy images (fog, image) obtained by leaving each photosensitive material for one day and night under the following environmental conditions and then making a plate using a fully automatic plate-making machine ELP-404V (manufactured by Fuji Photo Film Co., Ltd.) Image quality) was visually evaluated.

Environmental conditions at the time of imaging were 20 ° C 65% RH and 30 ° C 80% RH.

Note 5) Contact angle with water: Each photosensitive material was treated with an desensitizing solution ELP-E (manufactured by Fuji Photo Film Co., Ltd.) for 1 hour in an etching processor.
After passing through the surface to desensitize the surface of the photoconductive layer, a drop of 2 μm of distilled water is placed thereon, and the contact angle with the formed water is measured with a goniometer.

Note 6) Smearing of printed matter: Each photosensitive material is made into a plate using a fully automatic plate making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.) to form a toner image, and desensitized under the same conditions as above (Note 3). Offset printing press (Hamaduster Co., Ltd.)
500 sheets on high-quality paper using a HAMADASTAR 800SX, and visually check for soiling of all printed matter. This is referred to as background smear I of the printed matter.

The background smear II of the printed matter is tested in the same manner as the background smear I except that the desensitizing solution is diluted 5 times and the dampening solution for printing is diluted 2 times. The case of II corresponds to printing under more severe conditions than I.

Note 7) Printing durability: The number of sheets that can be printed without causing any problem in background smear in the non-image area and image quality in the image area by processing each photosensitive material under the evaluation conditions of print smear I described in Note 6) above. (The greater the number of prints, the better the printing durability).

As shown in Table 5, the photosensitive material of the present invention and Comparative Example A had good smoothness and electrostatic properties of the photoconductive layer, the actual copied image had no ground fog, and the copied image quality was clear. This is presumed to be due to the fact that the photoconductivity and the binder resin were sufficiently adsorbed and covered the back surface of the particles.

For the same reason, even when used as an offset master master, the desensitizing treatment with the desensitizing solution proceeds sufficiently, and the contact angle with water in the non-image area is as small as 15 degrees or less and sufficiently hydrophilized. Have been. Even when the printed material was actually printed and the background stain was observed, it was not recognized at all. However, in the case of Comparative Example A, when the strength test and the printing durability test of the photoconductive layer were performed, the film strength was not sufficient, and a serious problem occurred in durability.

On the other hand, in the case of the resin used in Comparative Example B, (30 ° C., 80
% RH), the obtained copied image deteriorated.

As a comparative example, the resin [R] produced in Resin Synthesis Example 3
An attempt was made to prepare a zinc oxide dispersion using -1, but a dispersion was not obtained, and a solidified body was formed, and a coating layer could not be obtained. Therefore, when only the high-molecular-weight resin [R] -3 having a reduced acid component was used as in Comparative Example C, the resulting photoreceptor significantly deteriorated the smoothness of the surface of the photosensitive layer, and exhibited both electrostatic characteristics and printability. It got worse enough to be impractical. This is thought to be due to the fact that the photoconductor and the binder resin are adsorbed, but that aggregation between the photoconductor particles occurs.

Further, the low molecular weight resin and high molecular weight resin [R] -3 of the present invention
In the case of Comparative Example D, the same result as that of Comparative Example C was obtained.

As described above, only the photosensitive material of the present invention was favorable in all aspects of the smoothness, film strength, electrostatic properties and printability of the photoconductive layer.

Examples 2 to 16 As low-molecular-weight resin [A], copolymers shown in Table 6 were produced in the same manner as in the production conditions of resin [A] -1 in Synthesis Example 1.

Same as Example 1 except that each of these resins [A] 8 g (as solid content) and resin [B] -132 g (as solid content) produced in Production Example 1 of Resin [B] were used. The procedure was followed to produce a photosensitive material.

Each characteristic was measured in the same manner as in Example 1. The smoothness and film strength of each light-sensitive material exhibited almost the same characteristics as those of the sample of Example 1. Table 7 shows the results of the electrostatic characteristics and the imaging performance.
It was noted in.

Each of the light-sensitive materials of the present invention is excellent in chargeability, dark charge retention rate, and photosensitivity.
% RH), a clear image free of background fog was obtained.

Example 17 and Comparative Example E A mixed solution of 48.5 g of ethyl methacrylate, 48.5 g of benzyl methacrylate, 3 g of methacrylic acid and 200 g of toluene was heated to a temperature of 105 ° C. in a nitrogen stream, and 10 g of azobisisobutyronitrile was added. For 8 hours.

The weight average molecular weight of the obtained copolymer [A] -17 was 6500.
And the glass transition point was 40 ° C.

6 g of the obtained copolymer (as solid content), resin [B]
34 g of resin [B] produced in Production Example 1 of zinc oxide 2
00g, heptamethine cyanine dye represented by the following structural formula
A mixture of 0.02 g, 0.05 g of phthalic anhydride and 300 g of toluene was dispersed in a ball mill for 2 hours to prepare a photosensitive layer formed product. Otherwise in the same manner as in Example 1, an electrophotographic photosensitive material was produced.

Comparative photosensitive material E A mixed solution of 48.5 g of ethyl methacrylate, 48.5 g of benzyl methacrylate, 3 g of methacrylic acid and 200 g of toluene was heated to 70 ° C. in a nitrogen stream, and 10 g of azobisisobutyronitrile was added. Allowed to react for hours.

The weight average molecular weight of the obtained copolymer [R] -4 was 36,0
The glass transition point was 54 ° C. As a binder resin,
Comparative photosensitive material E was prepared in the same manner as in Example 17 except that only 40 g (as solid content) of copolymer [R] -4 was used.

The electrostatic characteristics of these photosensitive materials were measured using a paper analyzer in the same manner as in Example 1. However, a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength: 830 nm) was used as a light source. The results are shown in Table-8.

Comparative Example E had poor smoothness and dark charge retention (DR
R.) was remarkably reduced. (The apparently small E _{1/10 and} high photosensitivity are due to the large DRR.) The DRR was further deteriorated as compared with Comparative Example C described above. ing. This indicates that conventionally known resins are remarkably affected by the type of spectral sensitizing dye used in combination and have a problem that they are easily affected. On the other hand, the binder resin of the present invention provides a photosensitive material which is extremely excellent in chargeability, dark charge retention and photosensitivity even when the chemical structure of the spectral sensitizing dye is greatly changed.

Examples 18 to 33 The same as Example 1 except that the resin [A] -1 and the resin [B] shown in Table 9 below were combined in a (3/17) weight ratio and used as a total resin amount of 40 g. Each light-sensitive material was produced by the operation of
In the same manner as in Example 1, the smoothness, film strength and electrostatic characteristics of each photosensitive material were measured.

Each of the photosensitive materials of the present invention has good photoconductive layer strength and electrostatic properties, and the actual copied image has clear image quality without background fog even under high temperature and high humidity (30 ° C. and 80% RH). Atsuta.

(Effects of the Invention) According to the present invention, an electrophotographic photosensitive material having excellent performance in all of the smoothness and strength of the photoconductive layer, the electrostatic properties, the image-capturability, and the background stain and printing durability of the printed matter. Is obtained.

Furthermore, the electrophotographic light-sensitive material of the present invention can have excellent photoconductive layer smoothness and electrostatic properties even when used in combination with various sensitizing dyes.

Claims (1)

(57) [Claims] 1. An electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductive material and a binder resin, wherein the binder resin comprises at least one of the following resins [A] and [B], respectively. An electrophotographic photosensitive member characterized by comprising. (I) Resin [A] having a weight average molecular weight of 1 × 10 ³ to 1 × 10 ⁴ and -PO ₃ H
₂ group, -COOH group, a copolymerization component containing at least one polar group selected from -SO ₃ H group and -OH group 0.05 to 20
Resin containing by weight. (Ii) Resin [B] A polymer containing a repeating unit represented by the following general formula (I), a part of which is crosslinked, and at least 1
One of the polymer main chain at one terminal only -PO ₃ H ₂ group, -SO ₃ H group,
A resin formed by bonding at least one type of polar group selected from -COOH groups and -OH groups. General formula (I) Wherein, X is -COO -, - OCO -, - CH 2 OCO -, - CH 2 COO
-, - O-or -SO ₂ - represent. Y represents a hydrocarbon group having 1 to 22 carbon atoms. a ₁ and a ₂ 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 hydrocarbon group having 1 to 8 carbon atoms. -Z-COO-Z (Z represents a hydrocarbon group having 1 to 18 carbon atoms).