JPH04330448A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To maintain good electrostatic property and to obtain a clear and good quality of an image by containing two kind of a specific resin in a binder resin. CONSTITUTION:The binder resin contains at least one kind of a resin which is a copolymer of 1X10<3>-2X10<4> weight av. molecular weight containing >=30wt.% of a polymer composition having a repeating unit expressed by the formula I and 0.5-15wt.% of a polymer composition having a polar group. And, the binder resin contains at least one kind of resin which is a star type copolymer of 2X10<4>-1X10<6> weight av. molecular weight, made by bonding at least three high mlecular chains containing the polymer composition (A) having the repeating unit expressed by the formula I and the polymer composition (B) having the polar group in the organic molecular chain, containing >=30wt.% of the composition (A) and 0.05-10wt.% of the composituon (B). In the formula I, each of (a<1>) and (a<2>) is hydrogen atom, halogen atom, cyano group or hydrocarbon group, R<3> is hydrocarbon group. Stable electrostatic property is constantly obtained under an atmosphere of low temp., low humidity or high temp., high humidity.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an electrophotographic photoreceptor.
Specifically, the present invention relates to an electrophotographic photoreceptor having excellent electrostatic properties and moisture resistance.

0002

2. Description of the Related 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.

Typical electrophotographic photoreceptors include photoreceptors having a photoconductive layer formed on a support and photoreceptors having an insulating layer on the surface, which are widely used. Photoreceptors, consisting of a support and at least one photoconductive layer, are used for imaging by most common electrophotographic processes, ie, charging, imagewise exposure and development, and optionally transfer.

Furthermore, a method of using an electrophotographic photoreceptor as an offset master plate for direct plate making is widely used. Particularly in recent years, direct electrophotographic lithography has become important as a method for printing high-quality printed matter on the order of several hundred to several thousand sheets. Under these circumstances, the binder resin used to form the photoconductive layer of the electrophotographic photoreceptor has excellent film-forming properties and the ability to disperse photoconductive powder into the binder resin. The formed recording layer has good adhesion to the base material, and the photoconductive layer of the recording layer has excellent charging ability, low dark decay, large light decay, little pre-exposure fatigue, and is easy to photograph. It is necessary to have various electrostatic properties and excellent imaging performance, such as the need to maintain these properties stably depending on changes in humidity.

Furthermore, research is being carried out on lithographic printing original plates using electrophotographic photoreceptors, and a photoconductive layer material that has both the electrostatic properties of an electrophotographic photoreceptor and the printing properties of a printing original plate has been developed. A binder resin is required.

It has been found that in a photoconductive layer containing at least an inorganic photoconductive material, a spectral sensitizing dye, and a binder resin, not only smoothness but also electrostatic properties are greatly affected by the chemical structure of the binder resin. Ta. In particular, in terms of electrostatic properties, the dark charge retention rate (D.R.R.) and photosensitivity are greatly affected.

On the other hand, according to the techniques described in JP-A-63-217354 and JP-A-64-70761, low molecular weight resins or polymers in which acidic group-containing polymerization components are randomly present in the polymer main chain. It has become possible to improve smoothness and electrostatic properties by using a low molecular weight resin with an acidic group bonded to one end of the main chain as a binder resin. These low molecular weight resins have the effect of sufficiently dispersing the photoconductor and suppressing aggregation of the photoconductors, and the inorganic resin does not interfere with the adsorption of the photoconductor and the spectral sensitizing dye. This is presumed to be due to sufficient adsorption to the stoichiometric defects of the photoconductor and a loose and sufficient coating of the surface of the photoconductor.

Due to its mechanism of action, the inorganic photoconductor, spectral sensitizing dye, and resin are relatively stable because they have a sufficient adsorption area even if the stoichiometric defect portion of the inorganic photoconductor varies slightly. It is inferred that peer interaction is preserved.

[0009] In order to make the mechanical strength of the photoconductive layer sufficient, which is insufficient with these low molecular weight resins alone, a technique of using other medium to high molecular weight resins in combination or a resin containing a curable group has been developed. Techniques for curing after film formation by using in combination are disclosed in JP-A-64-564, JP-A-63-220149, JP-A-63-220148, JP-A-1-280761, JP-A-1-116643, and JP-A-1-169455. , 1-2
No. 11766, No. 2-34859, No. 2-53064
No. 2-56558, Japanese Patent Application No. 1-163796,
No. 1-212994, No. 1-229379, No. 1-
It is described in No. 189245, etc.

0010

[Problem to be Solved by the Invention] However, even if these resins or combinations of resins are used, it is still insufficient to maintain stable performance when the environment changes significantly from high temperature and high humidity to low temperature and low humidity. I found out something. The scanning exposure method using semiconductor laser light requires longer exposure time than the conventional simultaneous exposure method using visible light across the entire surface, and there are restrictions on the exposure intensity, so electrostatic properties, especially dark charge retention properties , for light sensitivity,
Higher performance is required.

[0011] In particular, when a scanning exposure method using semiconductor laser light is adopted in an original plate for electrophotographic planographic printing, actual tests using a conventional photoreceptor show that
The above electrostatic properties are not fully satisfactory, especially E
The difference between 1/2 and E1/10 is large, and the gradation of the copied image becomes soft, and furthermore, it becomes difficult to reduce the residual potential after exposure, resulting in noticeable fogging of the copied image.
Further, even when printing as an offset master, problems such as pasting marks of the printed original appear on the printed matter.

Furthermore, in recent years, there has been a desire to realize a technology that faithfully reproduces not only copies of images consisting of line drawings and halftone dots, but also high-definition images consisting of continuous gradation using liquid developers. However, the above-mentioned known techniques could not fully satisfy these demands.

In conventionally known techniques, medium to high molecular weight resins that are used in combination with low molecular weight resins may deteriorate the electrostatic properties that have been improved by the low molecular weight resins, and in fact the above-mentioned An electrophotographic photoreceptor having a photoconductive layer using a combination of these known resins has the advantage of achieving faithful reproduction of high-definition images (particularly continuous-tone images) as described above, or of low-output images. It has become clear that problems may arise in imaging performance using a scanning exposure method using laser light.

The present invention is intended to improve the problems of conventionally known electrophotographic photoreceptors as described above. An object of the present invention is to provide an electrophotographic photoreceptor that always maintains stable and good electrostatic properties and produces clear, high-quality images even when the environment during copy image formation changes such as low temperature and low humidity or high temperature and high humidity. The goal is to provide the following.

Another object of the present invention is to provide a CPC electrophotographic photoreceptor that has excellent electrostatic properties and less environmental dependence. Another object of the present invention is to provide an electrophotographic photoreceptor that is effective in a scanning exposure method using semiconductor laser light.

A further object of the present invention is to use an electrophotographic lithographic printing original plate that has excellent electrostatic properties (particularly dark charge retention and photosensitivity) and is faithful to original images (particularly high-definition continuous tone images). To provide a lithographic printing original plate which reproduces a copy image, does not cause not only uniform background smearing on the entire surface of printed matter but also dotted smearing, and has excellent printing durability.

[0017]

[Means for Solving the Problems] The above object is to provide an electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductor, a spectral sensitizing dye, and a binder resin, the binder resin comprising:
It has been found that this can be achieved by an electrophotographic photoreceptor characterized by containing at least one resin [A] shown below and at least one resin [B] shown below. Resin [A] 30% by weight or more of a polymer component having a weight average molecular weight of 1 x 103 to 2 x 104 and consisting of repeating units represented by the following general formula (I), and -PO3 H2
, -SO3H, -COOH, -P(=O)(OH)R
1. A polymer component having at least one polar group selected from [R1 represents a hydrocarbon group or -OR2 (R2 represents a hydrocarbon group]] and a cyclic acid anhydride group.
A copolymer containing 5 to 15% by weight.

[0018]

[C4]

In formula (I), a1 and a2 each represent a hydrogen atom, a halogen atom, a cyano group or a hydrocarbon group. R
3 represents a hydrocarbon group. ] Resin [B] A polymer component (A) having a weight average molecular weight of 2 x 104 to 1 x 106 and consisting of repeating units represented by general formula (I) in the above resin [A] and the above resin [A] At least three polymer chains containing at least a polymer component (b) containing at least one polar group selected from the specific polar groups shown in the following are bonded to an organic molecule. 30% by weight or more of the polymer component (a) and 0.05 to 1% of the polymer component (b)
Star type copolymer containing 0% by weight.

That is, the binder resin of the present invention has the above general formula (
A low molecular weight random copolymer (resin [A]) containing the polymer component represented by I) and the above specific polar group-containing polymer component, the polymer component represented by formula (I) above, and the above specific polar group-containing polymer component. The star copolymer (resin [B]) is formed by bonding at least three polymer chains containing a specific polar group-containing component into an organic molecule.

As a result of various studies, as mentioned above, in the known technique of using a low molecular weight polar group-containing resin in combination with a medium to high molecular weight resin, the medium to high molecular weight resin used in combination,
It has been found that the electrostatic properties improved by the low molecular weight resin described above may deteriorate. It is also more important than expected that these medium to high molecular weight resins can interact more appropriately with the photoconductor, spectral sensitizing dye, and low molecular weight resins in the photoconductive layer. It has become clear that this is the cause.

As a result of repeated studies, we found that the component represented by the formula (I) according to the present invention and the polar group-containing resin were selected as medium to high molecular weight resins to be used in combination with the polar group-containing low molecular weight resin [A]. It has been discovered that the above-mentioned problem can be effectively solved by using a star-type copolymer in which a specific amount of three or more polymer chains containing the component are bonded to organic molecules.

This means that the binder resins [A] and [
Due to the synergistic effect of [B], the photoconductor particles are sufficiently dispersed and exist in a non-condensed state, and the spectral sensitizing dye is sufficiently adsorbed on the surface of the photoconductor particles, and the excess on the photoconductor surface is This is presumed to be due to the fact that the binding resin sufficiently adsorbs the active sites and compensates for the trapping.

That is, the low-molecular-weight resin [A] containing a specific polar group sufficiently adsorbs to the photoconductor particles and disperses the particles uniformly, and because its polymer chains are very short, they do not aggregate. It has important effects such as suppressing the spectral sensitizing dye and preventing absorption and alienation of the spectral sensitizing dye.

Furthermore, by using a star copolymer in which the same molecule contains at least three polymer chains containing a specific polymer component, the mechanical strength of the photoconductive layer can be sufficiently maintained. At the same time, improvements were made in electrostatic properties (particularly photosensitivity) and imaging performance (particularly reproducibility of continuous tone images). Although the details are unknown, this is because the polymer component blocks of this resin are regulated in a star shape, which improves the entanglement effect between polymer chains and also contributes to the effect of further improving electrostatic properties. Therefore, in the interaction between the photoconductor powder, the spectral sensitizing dye, and the resin [A], it is thought that this resin is appropriately involved in suppressing the adsorption and alienation of the dye or in the electrophotographic interaction. It will be done.

This effect was particularly remarkable with polymethine dyes or phthalocyanine pigments which are particularly effective as dyes for spectral sensitization of near-infrared to infrared light. On the other hand, when the electrophotographic photoreceptor of the present invention using photoconductive zinc oxide as a photoconductor is used as a conventionally known direct printing plate, it exhibits excellent imaging properties and extremely good water retention.

That is, the photoreceptor of the present invention, on which a copy image has been formed through an electrophotographic process, is chemically treated to desensitize the non-image area using a conventionally known desensitizing treatment liquid, and this is used as a printing original plate. It shows excellent performance as a printing original plate when printed by offset printing.

When the photoreceptor of the present invention was desensitized, the non-image area was sufficiently made hydrophilic and the water retention property was improved, resulting in a dramatic increase in the number of prints. This is because the above-mentioned zinc oxide particles are uniformly dispersed and the binder resin present on the surface of the zinc oxide particles is in an appropriate state, so that the desensitization reaction with the desensitization treatment solution does not occur and is rapid. This is thought to be due to the effective progression of the disease.

Furthermore, in the present invention, a low molecular weight resin [
A] contains a benzene ring or an unsubstituted naphthalene ring having specific substituents at the 2-position and/or the 2-position and the 6-position, as shown in the following general formulas (Ia) and (Ib). , a resin [A] containing a methacrylate component having a specific substituent and an acidic group component (hereinafter, this low molecular weight product is particularly referred to as resin [AA]) is preferable.

[0030]

[C5]

[0031]

[C6]

[In formulas (Ia) and (Ib), A1 and A2 each independently represent a hydrogen atom, a carbon number of 1 to
10 hydrocarbon groups, chlorine atom, bromine atom, -COR4
or -COOR4 (R4 represents a hydrocarbon group having 1 to 10 carbon atoms).

B1 and B2 each represent a single bond or a linking group having 1 to 4 linking atoms that connects -COO- to the benzene ring. ] When the above-mentioned specific resin [AA] is used, electrophotographic properties (particularly V10, D.R.R., and E1/10) can be further improved than in the case of resin [A].

The reason for this is unclear, but one reason is that the zinc oxide interface in the film is This is thought to be due to proper alignment of these polymer molecular chains.

The binder resin of the present invention will be explained in detail below. First, the resin [A] of the present invention will be explained. The weight average molecular weight of resin [A] is 1 x 103 to 2 x 1
04, and the glass transition point of the resin [A] is preferably -30°C to 110°C, more preferably -20°C to 90°C.
It is.

When the molecular weight of weight% [A] is less than 1×10 3 , the film forming ability decreases and sufficient film strength cannot be maintained, whereas when the molecular weight is greater than 2×10 4 , even the resin of the present invention , especially in photoreceptors using near-infrared to infrared spectral sensitizing dyes, fluctuations in dark decay retention and photosensitivity become somewhat large under harsh conditions of high temperature, high humidity, low temperature and low humidity, and stable If a duplicate image is obtained, the effect of the present invention will be diminished.

The proportion of the polymer component corresponding to the repeating unit of general formula (I) in the resin [A] is 30% by weight or more, preferably 50 to 97% by weight, and the proportion of the copolymer component containing a polar group is 0.5 to 15% by weight, preferably 1
~10% by weight.

[0038] The polar group content in resin [A] is 0.5
If it is less than % by weight, the initial potential will be low and sufficient image density will not be obtained. On the other hand, if the polar group content is more than 15% by weight, the dispersibility decreases no matter how low the molecular weight is, and furthermore, background smudge increases when used as an offset master.

Next, to further explain the repeating unit represented by the general formula (I) that is contained in the resin [A] in an amount of 30% by weight or more, a1 and a2 are a hydrogen atom, a halogen atom (for example, a chlorine atom, bromine atom), a cyano group, or an alkyl group having 1 to 4 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, etc.). R3 represents a hydrocarbon group, specifically an alkyl group, an aralkyl group or an aromatic group, preferably an aralkyl group or an aromatic group which is a hydrocarbon group containing a benzene ring or a naphthalene ring.

Furthermore, R3 preferably has 1 to 18 carbon atoms.
represents an optionally substituted hydrocarbon group. The substituent may be any substituent other than the polar group contained in the polar group-containing polymer component of the resin [A], such as a halogen atom (e.g. fluorine atom,
chlorine atom, bromine atom, etc.), -OR5, -COOR5
, -OCOR5 (R5 represents an alkyl group having 1 to 22 carbon atoms, such as a methyl group, an ethyl group, a propyl group,
butyl group, hexyl group, octyl group, decyl group, dodecyl group, hexadecyl group, octadecyl group, etc.). Preferred hydrocarbon groups include optionally substituted alkyl groups having 1 to 18 carbon atoms (for example,
Methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, octyl group, decyl group, dodecyl group,
Hexadecyl group, octadecyl group, 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3-
bromopropyl group, etc.), an optionally substituted alkenyl group having 4 to 18 carbon atoms (e.g., 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2-hexenyl group, 4-methyl-2-hexenyl group, etc.), 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), carbon number 5 to
8 optionally substituted alicyclic groups (for example, cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl group, etc.) or optionally substituted aromatic groups having 6 to 12 carbon atoms (for example, phenyl group) , naphthyl group, tolyl group, xylyl group, propylphenyl group, butylphenyl group, octylphenyl group, dodecylphenyl group, methoxyphenyl group, ethoxyphenyl group, butoxyphenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromo phenyl group, cyanophenyl group,
acetylphenyl group, methoxycarbonylphenyl group,
(ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecoylamidophenyl group, etc.).

In the hydrocarbon group represented by R3, R3
When is an aliphatic group, it is preferable that the component represented by formula (I) preferably contains 60% by weight or more of a hydrocarbon group having 1 to 5 carbon atoms.

[0042] Among the repeating units of general formula (I) which are components having such a substituent R3, polymer components of repeating units represented by the above general formula (Ia) and/or general formula (Ib) are more preferable. can be mentioned.

In formula (Ia), preferred A1 and A2 are, independently of each other, a hydrogen atom, a chlorine atom and a bromine atom, as well as a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. Alkyl groups (e.g. methyl group, ethyl group, propyl group, butyl group, aralkyl group having 7 to 9 carbon atoms (e.g. benzyl group, phenethyl group, 3-
phenylpropyl group, chlorobenzyl group, dichlorobenzyl group, bromobenzyl group, methylbenzyl group, methoxybenzyl group, chloromethylbenzyl group) and aryl groups (e.g. phenyl group, tolyl group, xylyl group, bromophenyl group, methoxyphenyl group) , chlorophenyl group,
dichlorophenyl group), and -COOR4 and -C
OOR4 (Preferably R4 has the above carbon number 1 to
Examples of preferred hydrocarbon groups include those listed above.

In formulas (Ia) and (Ib), B1
and B2 are each a single bond connecting -COO- and a benzene ring, or -(CH2)a- (a represents an integer of 1 to 3), -CH2OCO-, -CH2CH2OCO
-, -(CH2)b - (b represents an integer of 1 or 2), -CH2CH2O-, etc., with 1 to 4 connected atoms
, and more preferably a single bond or a linking group having 1 to 2 bonded atoms.

Formula (Ia) used in the resin [A] of the present invention
) or (Ib) are listed below. However, the scope of the present invention is not limited thereto. In addition, in the following (a-1) to (a-20), c is an integer of 1 to 4, d is 0 or an integer of 1 to 3,
e is an integer from 1 to 3, R6 is -CcH2c+1
or -(CH2)d-C6H5 (however, c,
d is the same as above), and D1 and D2 may be the same or different and represent a hydrogen atom, -Cl, -Br, or -I.

[0046]

[C7]

[0047]

[Chemical formula 8]

[0048]

[Chemical formula 9]

[0049]

[Chemical formula 10]

[0050]

[Chemical formula 11]

Next, the polar group-containing component of the low molecular weight resin [A] will be explained. The polar group is -PO3 H2,
-SO3H, -COOH, -P(=O)(OH)R1
-, a cyclic acid anhydride-containing group is preferred.

Here, -P(=O)(OH)R1 is
It represents a group represented by the following formula 12, where the R1
represents a hydrocarbon group or -OR2 group (R2 represents a hydrocarbon group), specifically R1 represents an optionally substituted hydrocarbon group having 1 to 6 carbon atoms (e.g. methyl group, ethyl group, propyl group). group, butyl group, 2-chloroethyl group, 2
-bromoethyl group, 2-fluoroethyl group, 3-chloropropyl group, 3-methoxypropyl group, 2-methoxybutyl group, benzyl group, phenyl group, propenyl group, methoxymethyl group, ethoxymethyl group, 2-ethoxyethyl group) etc., and R2 represents the same content as R1.

[0053]

[Chemical formula 12]

Further, the cyclic acid anhydride-containing group is a group containing at least one cyclic acid anhydride, and examples of the cyclic acid anhydride include aliphatic dicarboxylic anhydride, aromatic dicarboxylic anhydride, Things can be mentioned.

Examples of aliphatic dicarboxylic anhydrides include:
Succinic anhydride, glutaconic anhydride ring, maleic anhydride ring, cyclopentane-1,2-dicarboxylic anhydride ring, cyclohexane-1,2-dicarboxylic anhydride ring, cyclohexene-1,2-dicarboxylic anhydride ring acid anhydride ring, 2
, 3-bicyclo[2.2.2]octadicarboxylic acid anhydride rings, etc., and these rings include, for example, halogen atoms such as chlorine atoms and bromine atoms, methyl groups, ethyl groups, butyl groups, hexyl groups, etc. The alkyl group, etc. may be substituted.

Examples of aromatic dicarboxylic anhydrides include phthalic anhydride ring, naphthalene-dicarboxylic anhydride ring, pyridine-dicarboxylic anhydride ring, thiophene-dicarboxylic anhydride ring, etc. These rings are
For example, halogen atoms such as chlorine atom and bromine atom, alkyl groups such as methyl group, ethyl group, propyl group, butyl group, hydroxyl group, cyano group, nitro group, alkoxycarbonyl group (alkoxy groups include, for example, methoxy group, ethoxy groups) etc. may be substituted.

The polar group-containing copolymerization component of the resin [A] can be copolymerized with a monomer corresponding to the repeating unit of general formula (I) [including general formulas (Ia) and (Ib)]. Any vinyl compound containing the polar group that can be polymerized may be used.
It is described in "Handbook [Basic Edition]" Baifukan (published in 1986), etc. Specifically, acrylic acid, α- and/or β-substituted acrylic acid (e.g. α-acetoxy form, α-acetoxymethyl form, α-(2-amino)methyl form, α-
Chloro form, α-bromo form, α-fluoro form, α-tributylsilyl form, α-cyano form, β-chloro form, β-bromo form, α-chloro-β-methoxy form, α,β-dichloro form, etc. ), methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid half amides, crotonic acid, 2-alkenylcarboxylic acids (e.g. 2-pentenoic 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, vinylsulfonic acid, vinylphosphonic acid, dicarboxylic acids. Examples include half-ester derivatives of vinyl or allyl groups, ester derivatives of these carboxylic or sulfonic acids, and compounds containing the polar group in the substituent of amide derivatives. Examples of polar group-containing copolymer components are shown below. Here, b1 represents H or CH3, and b2
represents H, CH3 or CHCOOCH3, R7
represents an alkyl group having 1 to 4 carbon atoms, R8 represents an alkyl group having 1 to 6 carbon atoms, a benzyl group, or a phenyl group, f represents an integer of 1 to 3, and g represents an integer of 2 to 11. , h represents an integer of 1 to 11, i represents an integer of 2 to 4, and j represents an integer of 2 to 10.

[0058]

[Chemical formula 13]

[0059]

[Chemical formula 14]

[0060]

[Chemical formula 15]

[0061]

[Chemical formula 16]

[0062]

[Chemical formula 17]

[0063]

[Chemical formula 18]

[0064]

[Chemical formula 19]

[0065]

[C20]

[0066]

[C21]

[0067]

[C22]

[0068]

[C23]

[0069]

[C24]

Furthermore, the low molecular weight resin [A] includes monomers of general formula (I), (Ia) and/or (Ib) and the polar group-containing monomers described above, as well as other monomers other than these. Other monomers may be contained as copolymerization components.

Examples of such other copolymerization components include, for example, methacrylic esters, acrylic esters, and crotonic esters containing substituents other than those explained in general formula (I), as well as α-olefins. esters, vinyl carboxylates or allyl esters (for example, carboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, benzoic acid, naphthalene carboxylic acid, etc.), acrylonitrile, methacrylonitrile, vinyl ethers, itaconic esters (
(e.g. dimethyl ester, diethyl ester, etc.), acrylamides, methacrylamides, styrenes (e.g. styrene, vinyltoluene, chlorostyrene, hydroxystyrene, N,N-dimethylaminomethylstyrene, methoxycarbonylstyrene, methanesulfonyloxystyrene, vinyl naphthalene, etc.), vinyl sulfone-containing compounds, vinyl ketone-containing compounds, heterocyclic vinyls (
For example, vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylthiophene, vinylimidazoline, vinylpyrazole, vinyldioxane, vinylquinoline,
vinyltetrazole, vinyloxazine, etc.).

Resin [A] has a weight average molecular weight of 1×103
It is a random copolymer with a low amount of ~2 x 104, but these polymerization methods can be easily synthesized by radical polymerization, ionic polymerization, etc. by selecting polymerization conditions in conventionally known methods. can. In view of the monomers to be polymerized, the polymerization solvent, the reaction temperature setting, etc., it is advantageous and preferable to carry out a radical polymerization reaction from the viewpoint of purification, equipment, reaction method, etc.

Specifically, examples of the polymerization initiator include commonly known azobis-based initiators, peroxides, and the like. In particular, as a feature of synthesizing a low molecular weight substance, a known method such as increasing the amount of the initiator used or increasing the polymerization temperature setting may be applied. Specifically, the amount of initiator used can be in the range of 0.1 to 20% by weight based on the total monomers, and the polymerization temperature can be in the range of 30 to 200C.

Furthermore, a method of using a chain transfer agent in combination is also known. For example, a desired weight average molecular weight can be adjusted by using a mercapto compound, a halogenated compound, etc. in an amount of 0.01 to 10% by weight based on the total monomer amount.

Next, the resin [B] of the present invention will be explained. Resin [B] contains at least three polymer chains containing at least a polymer component (a) represented by the above general formula (I) and a specific polar group-containing polymer component (b) within the same organic molecule. It is a resin made of a so-called star copolymer that is bonded to a star type copolymer. That is, the polymer is schematically represented, for example, as follows.

[0076]

[C25]

[0077]

[C26]

In the above, X represents an organic molecule, and [P
[olymer] represents a polymer chain. Here, the three or more polymer chains bonded to the organic molecule may be structurally the same or different, and each has at least a polymer component represented by general formula (I) and a polar group-containing components in the above proportions. Furthermore, the lengths of each polymer chain may be the same or different.

The weight average molecular weight of resin [B] is 2×104
~1x106, preferably 3x104 ~5x10
It is 5. When the molecular weight of the resin [B] is smaller than 2 x 104, the film forming ability is reduced and sufficient film strength cannot be maintained, and when the molecular weight is larger than 1 x 106, the effect of the resin [B] of the present invention is reduced. However, the electronic properties are comparable to those of conventionally known resins.

The glass transition point of the resin [B] is -10°C
The temperature range is preferably 100°C to 100°C, more preferably 0°C to 90°C. Resin [B] is a branched star copolymer as described above, but the proportions of each polymer component in the entire copolymer are the same as described above.

[0081] The specific contents of the copolymerization component represented by the general formula (I) and the specific polar group-containing component contained in the resin [B] are the same as those explained for the resin [A]. Examples include:

The amount of the specific polar group-containing component in the star type copolymer [B] is 10
0.05 to 10 parts by weight per 0 parts by weight, more preferably 0 parts by weight
．． It is contained in a proportion of 1 to 5 parts by weight.

[0083] The polar group content in resin [B] is 0.0
If it is less than 5% by weight, the initial potential will be low and sufficient image density cannot be obtained, and if the polar group content is more than 10% by weight, the dispersibility will decrease and the film smoothness and electrophotographic properties will deteriorate. This is undesirable because the characteristics of high temperature and high humidity are reduced, and when used as an offset master, background smudge increases.

Furthermore, the specific polar group-containing polymer component contained in the resin [B] is 10% by weight based on the total amount of the specific polar group-containing polymer component contained in the resin [A]. ~
It is preferably used in a range of 50% by weight. If the amount is less than 10% by weight, electrophotographic properties (particularly charge retention in the dark and photosensitivity) are significantly reduced, and the strength of the film is also reduced. Moreover, if it exceeds 50% by weight, the uniformity of dispersion becomes insufficient, the electrophotographic properties deteriorate, and the water retention property as an offset original plate decreases.

[0085] Two or more types of polymerization components containing the above-mentioned specific polar groups may be contained in the polymer chain. On the other hand, the amount of the polymer component consisting of the repeating unit represented by the general formula (I) in the resin [B] is 30% by weight or more, preferably 30% by weight to 9% by weight based on the total weight of the copolymer.
9.95% by weight, more preferably 50% to 99.5% by weight
Weight%.

[0086] Resin [B] may also contain other copolymer components in addition to the above-mentioned polymer components, and such polymer components preferably correspond to repeating units of the following general formula (II). Examples include polymer components.

[0087]

[C27]

[In formula (II), X1 is -COO-, -
OCO-,-(CH2)p-OCO-,-(CH2
)p -COO- (p represents an integer from 1 to 3), -
O-, -SO2-, -CO-, -CON-Q2-,
-SO2 N-Q2 -, -CONHCOO-, -CO
It represents NHCONH- or -C6H4- (here, Q2 represents a hydrogen atom or a hydrocarbon group), and Q1 represents a hydrocarbon group.

m1 and m2 may be the same or different, and each represents the same content as a1 and a2 in the above formula (I). ] Here, in addition to a hydrogen atom, Q2 is preferably a hydrocarbon group such as an optionally substituted alkyl group having 1 to 18 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group). group, octyl group, decyl group, dodecyl group, hexadecyl group, octadecyl group, 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3-bromopropyl group etc.), an optionally substituted alkenyl group having 4 to 18 carbon atoms (e.g., 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group, 1-pentenyl group) group, 1-hexenyl group, 2-hexenyl group, 4-methyl-2-hexenyl group, etc.), optionally substituted aralkyl group having 7 to 12 carbon atoms (e.g., 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.), an optionally substituted alicyclic group having 5 to 8 carbon atoms (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 group, tolyl group, xylyl group, propylphenyl group, butylphenyl group, octylphenyl group, dodecylphenyl group, methoxyphenyl group) ,
Ethoxyphenyl group, butoxyphenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromophenyl group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarboxyphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecoylamidophenyl group, etc.).

When X1 represents -C6H4-,
The benzene ring may have a substituent. As substituents,
Halogen atoms (e.g. chlorine atom, bromine atom, etc.), alkyl groups (e.g. methyl group, ethyl group, propyl group, butyl group, chloromethyl group, methoxymethyl group, etc.), alkoxy groups (e.g. methoxy group, ethoxy group, propioxy group) , butoxy group, etc.). Q1 represents a hydrocarbon group, and a preferable hydrocarbon group has 1 to 1 carbon atoms.
22 optionally substituted alkyl groups (for example, methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group) , 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-methoxycarbonylethyl group, 2-
methoxyethyl group, 3-bromopropyl group, etc.), optionally substituted alkenyl groups having 4 to 18 carbon atoms (for example, 2
-Methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2-hexenyl group, 4-
methyl-2-hexenyl group, etc.), optionally substituted aralkyl groups having 7 to 12 carbon atoms (e.g., 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.), optionally substituted alicyclic groups having 5 to 8 carbon atoms (e.g., cyclohexyl group, 2- cyclohexylethyl group, 2-cyclopentylethyl group, etc.), carbon number 6-1
2 optionally substituted aromatic groups (e.g. phenyl group,
Naphthyl group, tolyl group, xylyl group, propylphenyl group, butylphenyl group, octylphenyl group, dodecylphenyl group, methoxyphenyl group, ethoxyphenyl group, butoxyphenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromophenyl group group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group,
butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecoylamidophenyl group, etc.).

More preferably, in general formula (II), X1 is -COO-, -OCO-, -CH2OCO
-, -CH2 COO-, -O-, -CONH-, -S
Represents O2 NH- or -C6 H4 -.

Furthermore, as a polymer component that can be contained in the resin [B] together with the polymer component represented by formula (II), other repeating units that can be copolymerized with the polymer component represented by formula (II) are also included. Monomers corresponding to, for example acrylonitrile,
methacrylonitrile, heterocyclic vinyls (e.g. vinylpyridine, vinylimidazole, vinylpyrrolidone, vinylthiophene, vinylpyrazole, vinyldioxane,
vinyloxazine, etc.). These other monomers are used in an amount not exceeding 20 parts by weight based on 100 parts by weight of the total polymer component of resin [B].

The star copolymer [B] of the present invention can be synthesized using a conventional method for synthesizing a star polymer of a monomer containing a polar group and having a polymerizable double bond group. can. For example, one example is a polymerization reaction using a carbanion as an initiator. Specifically, M. Mort
on, T. E. Helminiak etal, J.
Polym. Sci. , 57, 471 (1962), B
．． Gordon III, M. Blumenthal, J.
．． E. Loftus, etal, Polym. Bull
．． , 11, 349 (1984), R. B. Bates,
W. A. Beavers, etal, J. Org. Ch
em. , 44, 3800 (1979).

[0094] However, when using this reaction, the "
A specific polar group is used as a protected functional group, and after polymerization, the protecting group is removed. The protection of the specific polar group of the present invention with a protecting group and the removal of the protecting group (deprotection reaction) can be easily carried out using conventionally known knowledge. For example, there are various descriptions in the above-mentioned cited documents, and furthermore, Yoshio Iwakura, Keisuke Kurita, "Reactive Polymer" published by Kodansha Co., Ltd. (1977), T. W. Gr.
eene, “Protective Groups
in Organic Synthesis”,
John Wiley & Sons (1981)
, J. F. W. McOmie, “Protective
Groups in Organic Ch.
emistry” Plenum Press, (19
This can be carried out by appropriately selecting a method described in detail in a review such as 1973).

Another method is to use the monomer of the present invention with the specific polar group left unprotected, and use a compound containing a dithiocarbament group and/or a compound containing a xanthate group as an initiator. It can also be synthesized by performing a polymerization reaction under light irradiation. For example, Takayuki Otsu, Polymer, 3
7, 248 (1988), Shunichi Himori, Ryuichi Otsu, Pol
ym. Rep. Jap. 37.3508 (1988),
JP-A-64-111, JP-A-64-26619, Azuma Nobuyuki et al., Polymer Preprints, Ja
Pan, 36, (6), 1511 (1987), M. N
iwa, N. Higashi, etal, J. Macr
omol. Sci. Chem. A24(5), 567(
It can be synthesized according to the synthesis method described in (1987) et al.

As the binder resin for the photoconductive layer of the present invention, in addition to the resin [A] and resin [B] of the present invention, the above-mentioned known resins for inorganic photoconductors can also be used in combination. However, the usage ratio of these other resins is 10% of the total binder resin.
It is preferable that the amount does not exceed 30% by weight based on 0 parts by weight. If this ratio is exceeded, the effect of the present invention will be significantly reduced.

Typical examples of other resins that can be used in combination include vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-methacrylate copolymer, methacrylate copolymer, and acrylate copolymer. , vinyl acetate copolymer, polyvinyl butyral, alkyd resin, silicone resin, epoxy resin, epoxy ester resin, polyester resin, etc.

Specifically, Ryuji Shibata and Jiro Ishiwata, "Polymer" Vol. 17, p. 278 (1968), Harumi Miyamoto and Hidehiko Takei, "Imaging", 1973 (No. 8), p. 9,
Edited by Koichi Nakamura "Practical technology of binders for insulating materials" No. 10
Chapter, C. H. C. Publishing (1985), D. D. Ta
tt, S. C. Heidecker, Tappi, 49
(No. 10), 439 (1966), E. S. Bal
tazzi, R. G. Blanclotte eta
l, Photo. Sci. Eng. 16 (No. 5),
354 (1972), Nguyen Tranh Khe, Shimizu
Isamu, Eiichi Inoue, Journal of the Electrophotography Society 18 (No. 2), 28
(1980), JP-B No. 50-31011, JP-A-53
-54027, 54-20735, 57-20
Examples include resins disclosed in Publications No. 2544 and No. 58-68046.

The total amount of binder resin used in the photoconductive layer of the present invention is 1 part by weight based on 100 parts by weight of the inorganic photoconductor.
It is preferably 0 parts by weight to 100 parts by weight, more preferably 15 parts by weight to 50 parts by weight.

[0100] The ratio of resin [A] and resin [B] used in the present invention is 0.05 to 0 in weight ratio of resin [A]/resin [B].
．． The ratio is preferably 8/0.95 to 0.20, more preferably 0.10 to 0.50/0.90 to 0.50.

If the total amount of the binder resin is less than 10 parts by weight, the film strength of the photoconductive layer cannot be maintained. If the amount exceeds 100 parts by weight, the electrostatic properties will deteriorate, resulting in deterioration of copied images in actual imaging performance.

[0102] Furthermore, in the ratio of resin [A] and resin [B] used in the present invention, if the weight ratio of resin [A] is less than 0.05, the effect of improving electrostatic properties will be diminished. On the other hand, 0.8
If this is the case, the film strength of the photoconductive layer may not be maintained sufficiently (especially as an original plate for electrophotographic lithographic printing).

[0103] Inorganic photoconductive materials used in the present invention include zinc oxide, titanium oxide, zinc sulfide, cadmium sulfide,
Cadmium carbonate, zinc selenide, cadmium selenide,
Examples include tellurium selenide and lead sulfide.

Spectral sensitizing dyes used in the present invention include:
Various dyes may be used alone or in combination as necessary. For example, Harumi Miyamoto, Hidehiko Takei, Imaging 1973 (N
o. 8) Page 12, C. J. Young et al., R.C.A.
Review 15, 469 (1054), Wataru Kiyota, Transactions of the Institute of Electrical Communication Engineers J63-C (No. 2),
97 (1980), Yuji Harasaki et al., Industrial Science Magazine 6678
and 188 (1963), Tadaaki Tani, Journal of the Photographic Society of Japan 35
Carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, cited in reviews such as , 208 (1972), etc.
Examples include xanthene dyes, phthalein dyes, polymethine dyes (for example, oxonol dyes, merocyanine dyes, cyanine dyes, rhodacyanine dyes, styryl dyes, etc.), phthalocyanine dyes (which may contain metals), and the like.

More specifically, carbonium dyes, triphenylmethane dyes, xanthene dyes, and phthalein dyes are mainly used in the Japanese Patent Publication No. 51-45.
No. 2, JP-A-50-90334, JP-A No. 50-11422
No. 7, No. 53-39130, No. 53-82353,
U.S. Patent Nos. 3,052,540 and 4,054,45
Examples include those described in No. 0, JP-A-57-16456, and the like.

Polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes and rhodacyanine dyes include F. M. Hammer “The Cya”
nine Dyes and Related C
It is possible to use the pigments described in ".
More specifically, U.S. Pat. No. 3,047,384, U.S. Pat.
, No. 125,447, No. 3,128,179, No. 3,
132,942, British Patent No. 3,622,317, British Patent No. 1,226,892, British Patent No. 1,309,274, British Patent No. 1,405,898, Japanese Patent Publication No. 48-7814, British Patent No. 5
Examples include dyes described in No. 5-18892 and the like.

Furthermore, as a polymethine dye that spectrally sensitizes in the near-infrared to infrared light region with a long wavelength of 700 nm or more, JP-A No. 4
No. 7-840, No. 47-44180, Special Publication No. 51-4
No. 1061, JP-A-49-5034, JP-A No. 49-451
No. 22, No. 57-46245, No. 56-35141, No. 57-157254, No. 61-26044, No. 61-27551, U.S. Patent No. 3,619,154, No. 4,175,956 , “Research D.
isclosure” 1982, 216, No. 117~
Examples include those described on page 118. The photoreceptor of the present invention is excellent in that its performance does not easily vary depending on the sensitizing dye, even when various sensitizing dyes are used together. Furthermore, if necessary, various conventionally known additives for electrophotographic photosensitive layers such as chemical sensitizers can be used in combination. for example,
Review mentioned above: Imaging 1973 (No. 8) No. 1
Electron-accepting compounds (e.g., halogens, benzoquinones, chloranil, acid anhydrides, organic carboxylic acids, etc.) cited in reviews such as page 2, Hiroshi Komon et al., “Development and practical application of bacterial photoconductive materials and photoreceptors,” Vol. Examples include polyarylalkane compounds, hindered phenol compounds, and p-phenylenediamine compounds cited in Chapters 4 to 6 of the review published by Nihon Kagaku Information Co., Ltd. (1986).

The amount of these various additives added is not particularly limited, but is usually 0.0 parts by weight per 100 parts by weight of the photoconductor.
001 to 2.0 parts by weight. The thickness of the photoconductive layer is 1 to 1
00μ, especially 10 to 50μ is suitable.

Further, when a photoconductive layer is used as the charge generation layer of a photoconductor with a stacked structure 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 0.0μ. 5
μ is preferred.

[0110] 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 for 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 5 to 70 μm.
In particular, it is set to 10 to 50μ. Charge transport materials for the laminated photoreceptor include polyvinylcarbazole, oxazole dyes, pyrazoline dyes, triphenylmethane dyes, and the like. The thickness of the charge transport layer is 5 to 40
μ, particularly 10 to 30 μ is suitable.

Typical resins used for forming the insulating layer or charge transport layer include polystyrene resin, polyester resin, cellulose resin, polyether resin,
Thermoplastic resins and curable resins such as vinyl chloride resin, vinyl acetate resin, vinyl chloride vinyl acid copolymer resin, polyacrylic resin, polyolefin resin, urethane resin, polyester resin, epoxy resin, melamine resin, and silicone resin 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, metal, paper, plastic sheet, etc. are basically impregnated with a low-resistance substance, just as in the conventional case. Those that have been subjected to conductive treatment such as by applying a conductive coating, those that have been coated with at least one layer for the purpose of imparting conductivity to the back side of the base (the opposite side to the side on which the photosensitive layer is provided) and preventing curling, etc.
One in which a water-resistant adhesive layer is provided on the surface of the support, one in which at least one or more pre-coated layer is provided on the surface layer of the support as required, and one in which the conductive plastic substrate is vapor-deposited with Al, etc. You can use a laminated one.

[0114] Specifically, as an example of a conductive substrate or a conductive material, see Yukio Sakamoto, Electrophotography, 14 (No. 1).
, P2-11 (1975), Hiroyuki Moriga, "Introductory Chemistry of Special Papers" Kobunshi Publishing (1975), M. F. Hoove
r, J. Macromol. Sci. Chem. A-4
(6), pages 1327 to 1417 (1970), etc. are used.

The electrophotographic photoreceptor of the present invention can be used in applications using all conventionally known electrophotographic processes. That is, the photoreceptor of the present invention can be used for both the PPC method and the CPC method, and
As the developer, any combination of a dry developer or a liquid developer can be used.

In particular, since it is possible to form a high-definition faithful copy image of the original, the effects of the present invention are more effectively achieved when used in combination with a liquid developer. In addition, by combining it with a color developer, it is possible to produce not only black and white copies, but also
It can also be applied to color copies (for example, Kuro Takizawa, "Photography Industry" 33, 34 (1975), Masayasu Anzai, "IEICE Technical Research Report 77, 17 (1975),
7 years) etc.).

[0117] Furthermore, it is also effective in systems for other uses using recent electrophotographic processes. For example, the photoreceptor of the present invention using photoconductive zinc oxide as a photoconductor can be used as an original plate for offset lithographic printing, and can also be used as a photoconductive zinc oxide or photoconductive titanium oxide, which is non-polluting and has good whiteness. The photoreceptor can be used as a marking material for a printing plate or a color proof used in an offset printing process.

[0118]

[Examples] Examples of the present invention are illustrated below, but the content of the present invention is not limited thereto.

[Synthesis of Resin [A]] Synthesis Example 1 of Resin [A]: [A-1] A mixed solution of 95 g of benzyl methacrylate, 5 g of acrylic acid, and 200 g of toluene was heated to a temperature of 90° C. under a nitrogen stream. Later, A. I. B. N. 6.0 g was added and reacted for 4 hours. Furthermore, A. I. B. N. 2 g was added and reacted for 2 hours. The weight average molecular weight (abbreviated as Mw) of the obtained copolymer [A-1] was 8,500.

[0120]

[C28]

Synthesis Examples 2 to 28 of resin [A]: [A-2]
~[A-28] Resins [A-2] to [A-28] in Table A below were synthesized by operating the same polymerization conditions as in Synthesis Example 1 of Resin [A].

[0122] Mw of each resin [A] is 5.0×103 ~
It was 9.0×103.

[0123]

[Table 1]

[0124]

[Table 2]

[0125]

[Table 3]

[0126]

[Table 4]

[0127]

[Table 5]

[0128]

[Table 6]

[0129]

[Table 7]

Synthesis example 29 of resin [A]: [A-29] 2
A mixed solution of 95 g of 6-dichlorophenyl methacrylate, 5 g of acrylic acid, 2 g of n-dodecyl mercaptan and 200 g of toluene was heated to a temperature of 80° C. under a nitrogen stream. I. B. N. 2g was added and reacted for 4 hours, then A. I. B. N. Add 0.5g and continue for 2 hours. I.
B. N. 0.5 g was added and reacted for 3 hours. After cooling, it was reprecipitated into 2 liters of a mixed solution of methanol/water (9/1), and the precipitate was collected by decantation and dried under reduced pressure. The yield of the waxy copolymer obtained was 78 g, and the Mw was 6.
It was 3×103. [Synthesis of resin [B]] Synthesis example 1 of resin [B]: [B-1] 67 g of methyl methacrylate, 32 g of methyl acrylate
g, 1 g of acrylic acid and initiator [I-1] 1 having the following structure
A mixed solution of 7.5 g and 150 g of tetrahydrofuran was heated to 50° C. under a nitrogen stream. 400 in this solution
Photopolymerization was carried out by irradiating light for 10 hours with a W high-pressure mercury lamp from a distance of 10 cm through a glass filter. The obtained reaction product was reprecipitated in 1 liter of methanol, the precipitate was collected and dried, and the yield was 72 g with a weight average molecular weight (Mw: resin [B
] A polymer was obtained whose Mw was 5×10 4 (value determined by GPC method in terms of polystyrene).

[0131]

[C29]

[0132]

[C30]

Synthesis Example 2 of Resin [B]: [B-2] Resin [
In Synthesis Example 1 of B], 17.5 g of initiator [I-1]
The procedure was carried out under the same conditions as in Synthesis Example 1, except that 10 g of initiator [I-2] having the following structure was used instead of . The yield of the obtained polymer was 75 g, and the Mw was 6 x 104.

[0134]

[Chemical formula 31]

[0135]

[C32]

Synthesis examples 3 to 9 of resin [B]: [B-3] to
[B-9] Methyl methacrylate 65g, methyl acrylate 30
Each polymer was obtained by operating under the same conditions as in Synthesis Example 1, except that a mixed solution of 1 g, 4 g of N-vinylpyrrolidone, 1 g of methacrylic acid, 0.0312 mol of the initiator shown in Table B below, and 100 g of tetrahydrofuran was used. Ta.

[0137] The Mw of each polymer obtained is 6 x 104 ~
The range was 8×104.

[0138]

[Table 8]

[0139]

[Table 9]

[0140]

[Table 10]

Synthesis Examples 10 to 15 of Resin [B]: [B-1
0] to [B-15] In Synthesis Example 1 of Resin [B], instead of methyl methacrylate, methyl acrylate and acrylic acid,
In addition to using each monomer corresponding to the polymerization component described in C,
Each polymer was obtained by operating under the same conditions as in Synthesis Example 1. The Mw of each polymer obtained is 5 x 104 to 6 x 104
It was within the range of

[0142]

[Table 11]

[0143]

[Table 12]

Synthesis Examples 16 to 19 of Resin [B]: [B-1
6] ~ [B-19] Methyl methacrylate 71.5g, methyl acrylate 25g, acrylonitrile 2.5g, acrylic acid 1g,
Each polymer was obtained by operating under the same conditions as in Synthesis Example 1, except that a mixed solution of 0.0315 mol of the initiator shown in Table D below and 100 g of tetrahydrofuran was used.

[0145] The Mw of each polymer obtained is 5 x 104 ~
The range was 8×104.

[0146]

[Table 13]

[0147]

[Table 14]

Synthesis Examples 20 to 24 of Resin [B]: [B-2
0] to [B-24] 11.3 g of the initiator [I-2] and a mixture of monomers corresponding to each polymer component shown in Table-E below were heated to a temperature of 40°C under a nitrogen stream. Warmed.

[0149] The following operation was carried out in the same manner as in Synthesis Example 1, and after light irradiation and polymerization, the solid content was taken out and dissolved in 250 ml of tetrahydrofuran, and then reprecipitated in 1.5 liters of methanol to remove the precipitate. It was collected by filtration and dried. The yield of each polymer is 60 to 75 g, and the Mw is 6 x 104 to 8 x 104.
Met.

[0150]

[Table 15]

[0151]

[Table 16]

Example 1 and Comparative Examples 1 and 2 Resin [A-
1] 6g (as solid content), resin [B-1] 34g (
(as solid content), 200g of photoconductive zinc oxide, 0.018g of cyanine dye [I] having the following structure, 0.018g of phthalic anhydride.
A mixture of 15 g and 300 g of toluene was heated in a homogenizer (manufactured by Nippon Seiki Co., Ltd.) at a rotation speed of 6 x 103 rpm.
Dispersion was carried out for 10 minutes to prepare a photosensitive layer-forming product, which was coated on electrically conductive treated paper using a wire bar so that the dry adhesion amount was 18 g/m2, dried at 110°C for 10 seconds, and then An electrophotographic light-sensitive material was prepared by leaving it in the dark under conditions of 20° C. and 65% RH for 24 hours.

[0153]

[Chemical formula 33]

Comparative Example 1: In Example 1, resin [B-
1] 34g of resin with the following structure [R-1] instead of 34g
An electrophotographic light-sensitive material was produced in the same manner as in Example 1, except that .

[0155]

[C34]

Comparative Example 2: In Example 1, resin [B-
1] Instead of 34 g, use resin [R-2] 34 with the following structure.
An electrophotographic light-sensitive material was produced in the same manner as in Example 1, except that g was used.

[0157]

[C35]

[0158] Regarding these photosensitive materials, electrostatic properties, imaging properties, and environmental conditions (20°C, 65% RH) and (30°C
, 80% RH). The above results are summarized in Table-F.

[0159]

[Table 17]

[0160] The implementation of the evaluation items shown in Table F is as follows. Note 1) Electrostatic properties: Each photosensitive material was analyzed using a paper analyzer (Paper Analyzer SP-428 model manufactured by Kawaguchi Electric Co., Ltd.) in a dark room at a temperature of 20°C and 65% RH.
After performing corona discharge at -6 kV for 20 seconds, the sample was left for 10 seconds, and the surface potential V10 at this time was measured. Next, the potential V100 was measured after being allowed to stand still in the dark for 90 seconds, and the retention of the potential after dark decay for 90 seconds, that is, the dark decay retention rate [DRR (%)] was determined as (V100/V10).
It was calculated as x100 (%).

[0161] Also, the surface of the photoconductive layer was heated to -40 by corona discharge.
After charging to 0V, the surface of the photoconductive layer is heated with a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength: 780 nm).
Irradiate with light, find the time until the surface potential (V10) attenuates to 1/10, and calculate the exposure amount E1/10 (erg
/cm2). Similarly, the surface potential (V10
) is attenuated to 1/100, and the exposure amount E1/100 (erg/cm2) is calculated from this. The environmental conditions at the time of measurement were 20°C and 65% RH (I).
The test was carried out at 30° C. and 80% RH (II). Note 2) Imaging performance: After leaving each photosensitive material for one day and night under the following environmental conditions, each photosensitive material was charged at -6 kV, and a gallium-aluminum-arsenic with 2.8 mW output was used as a light source.
Using a semiconductor laser (oscillation wavelength: 780 nm), the surface of the photosensitive material was exposed under an irradiation dose of 64 erg/cm2 at a pitch of 25 μm and a scanning speed of 300 m/sec. ELP-T (Fuji Photo Film Co., Ltd.) was Copied images (fogging, image quality) obtained by developing with Isopara Suiko Isopar G (manufactured by Shell Chemical Co., Ltd.) and fixing after washing with a rinse solution of solvent .

[0162] The environmental conditions during imaging were 20°C, 65% RH (I
) and 30°C and 80% RH (II). As shown in Table F, the photosensitive material of the present invention had good electrostatic properties, and the actual copied images had no background fog and the quality of the copied images was clear. On the other hand, Comparative Examples 1 and 2 have photosensitivity (E1/10 and E1/10).
100), and even in actual copied images, fading of thin lines, letters, etc., and slight background fog remained without being removed even after rinsing.

[0163]Also, although it did not match the electrostatic characteristics, unevenness occurred in the intermediate density of the continuous tone portion of the copied original. E1/10 between the photoconductor of the present invention and the photoconductor of the comparative example
0 The values are significantly different. The E1/100 value indicates how much potential remains in the non-image area (already exposed area) after exposure in actual imaging performance.
The smaller this value is, the less background smear will occur in the non-image area after development.

Specifically, it is necessary to make the residual potential below -10V, that is, how much exposure is required to actually make VR below -10V? In the scanning exposure method, it is very important to reduce the VR to −10 V or less with a small exposure amount in terms of the design of the optical system of the copying machine (device cost, precision of the optical system optical path, etc.).

From the above, it is possible to obtain an electrophotographic photoreceptor that satisfies electrostatic properties and imaging performance only when the resin of the present invention is used, which is especially advantageous for photoreceptor systems using semiconductor laser light scanning exposure method. It became clear that Example 2 Resin [A-3] 5g (as solid content), resin [B-2]
] 35g (as solid content), photoconductive zinc oxide 200
g, 0.020 g of methine dye [II] with the following structure, N-
0.20 g of hydroxymaleimide and 30 g of toluene
0 g of the mixture was operated in the same manner as in Example 1 to produce an electrophotographic light-sensitive material.

[0166]

[C36]

Film properties (surface smoothness) of this photosensitive material,
The electrostatic properties, imaging properties, and environmental conditions were set to 30° C. and 80% RH.The electrostatic properties and imaging properties were investigated. Furthermore, the printability when used as an original plate for electrophotographic planographic printing was investigated.

[0168]

[Table 18]

[0169] The implementation of the evaluation items shown in Table G is as follows. Note 3) Smoothness of surface layer: The obtained photosensitive material was measured using a Beck smoothness tester (manufactured by Kumagai Riko Co., Ltd.) with an air capacity of 1 c.
The smoothness (sec/cc) was measured under the conditions of c. Note 4) Contact angle with water: Desensitizing treatment liquid EP for each photosensitive material
Using a solution prepared by diluting L-EX (manufactured by Fuji Photo Film Co., Ltd.) twice with distilled water,
After passing through the photoconductive layer to desensitize it, a drop of 2 μl of distilled water is placed on it, and the contact angle with the water formed is measured using a goniometer. Note 5) Printing durability: Make a plate under the same conditions as the imaging performance in Note 2) above to form a toner image, desensitize it under the same conditions as Note 4) above, and use this as an offset master. This indicates the number of sheets that can be printed using an offset printing machine (Oliver Model 52 manufactured by Sakurai Seisakusho Co., Ltd.) without causing problems with background stains in non-image areas or image quality in image areas (the higher the number of sheets printed, the longer the printing durability (indicates that the condition is good).

As shown in Table G, the photosensitive material of the present invention is
The smooth film of the photoconductive layer had good mechanical strength and electrostatic properties, and the actual copied image had no background fog and the quality of the copied image was clear. This means that the photoconductor and the binder resin are sufficiently adsorbed.
Moreover, it is presumed that this is due to the coating of the particle surface. For the same reason, even when used as an offset master original, the desensitizing treatment with the desensitizing treatment liquid progresses sufficiently, and the contact angle with water in the non-image area is as small as 10 degrees or less, making it sufficiently hydrophilic. It can be seen that When actually printing and observing the background smear on the printed matter, no background smudge was observed, and 10,000 printed matter with clear image quality were obtained.

[0171] The above describes the resin [A] and resin [A] of the present invention.
B] appropriately interacts with the zinc oxide particles, forming a state in which the desensitizing reaction by the desensitizing treatment liquid can proceed easily and sufficiently, and the film strength is improved by the action of the resin [B]. This shows that significant improvements have been achieved. Examples 3 to 18 In Example 2, resin [A-3] and resin [B-2]
In place of, each resin [A] and each resin [B] in Table-H below
Each electrophotographic photoreceptor was produced in the same manner as in Example 1, except that .

[0172] Electrostatic properties were measured in the same manner as in Example 2. The results are shown in Table H.

[0173]

[Table 19]

[0174] Furthermore, when we investigated the actual imaging properties of these photosensitive materials, we were able to obtain clear reproduced images with good reproducibility of fine lines and characters, no unevenness in halftones, and no background fog. Ta.

[0175] Further, when printing was performed in the same manner as in Example 2 using the original offset master plate, at least 10,000 or more prints could be made in each case. From the above, each of the photosensitive materials of the present invention was good in all respects of the smoothness of the photoconductive layer, film strength, electrostatic properties, and printability.

Furthermore, it was found that the electrostatic properties were further improved by using resin [AA]. Examples 19 to 22 Electrophotographic materials were produced under the same conditions as in Example 1, except that the methine dye [I] used in Example 1 was replaced with the dyes shown in Table I below.

[0177]

[Table 20]

All of the photosensitive materials of the present invention have excellent chargeability, dark charge retention, and photosensitivity, and even in the harsh conditions of high temperature and high humidity (30° C., 80% RH), even in actual copied images,
Providing clear images with no background fog. Examples 23 and 24 and Comparative Example 3 6.5 g of either resin [A-2] (Example 23) or resin [A-7] (Example 24), resin [B-8] 33.
A mixture of 5 g, 200 g of zinc oxide, 0.02 g of uranine, 0.03 g of methine dye [VII] with the following structure, 0.03 g of methine dye [VIII] with the following structure, 0.18 g of p-hydroxybenzoic acid, and 300 g of toluene was heated in a homogenizer. A photosensitive layer-formed product was prepared by dispersing the product in a 7×103 rpm chamber for 10 minutes, and then applied it to conductive-treated paper with a wire bar to a dry adhesion amount of 20 g/m2, and heated at 110°C. Dry for 20 seconds. Then 20 minutes in the dark
Each electrophotographic photoreceptor was produced by leaving it for 24 hours under conditions of 65% RH.

[0179]

[C37]

[0180]

[C38]

Comparative Example 3 A photosensitive material was produced in the same manner as in Example 23, except that resin [R-3] having the following structure was used instead of resin [B-8].

[0182]

[C39]

[0183] In the same manner as in Example 1, the characteristics of each photosensitive material were investigated. The results are summarized in Table J below.

[0184]

[Table 21]

[0185] In the above measurements, the electrostatic properties and imaging properties were carried out in the same manner as in Example 1, except that the following operations were followed. Note 6) Method for measuring electrostatic properties E1/10 and E1/100 After the surface of the photoconductive layer was charged to -400V by corona discharge, the surface of the photoconductive layer was irradiated with visible light at an illuminance of 2.0 lux. , the surface potential (V10) is 1/10 or E
The time required for the light to attenuate to 1/100 is determined, and from this the exposure amount E1/10 or E1/100 (lux/second) is calculated. Note 7) Imaging properties: After each photosensitive material was left for one day and night under the following environmental conditions, it was plate-made using a fully automatic plate-making machine ELP-404V (manufactured by Fuji Photo Film Co., Ltd.) using ELP-T as a toner. The copied images (fogging, image quality) were visually evaluated. The environmental conditions during imaging were 20°C and 65%RH.
(I) and (II) at 30° C. and 80% RH. However, the manuscript for copying (ie, the draft manuscript) was created by cutting out another original and pasting it together.

No difference was observed in the smoothness and strength of the photoconductive layer among the photosensitive materials. but,
In terms of electrostatic properties, Comparative Example 3 particularly has a photosensitivity E1/10.
The value of 0 was large, and this was further exacerbated by high temperature and high humidity, resulting in deterioration. The electrostatic properties of the photosensitive material of the present invention are good, and the resin having a specific substituent [
Example 24 using E
The value of 1/100 has become smaller.

When examining the actual imaging performance, in Comparative Example 3, in addition to the original as a copy image, the frame of the cut out and pasted part (that is, the pasting trace) was recognized as background stains in the non-image area. Ta. However, in all cases of the present invention, clear images without background stains were obtained.

Furthermore, when these were desensitized and printed as offset printing original plates, 10,000 prints with clear image quality and no background smudge were obtained for all of the products of the present invention. However, in Comparative Example 3, the above-mentioned pasting marks were not removed even with the desensitization treatment, and were generated from the printed matter.

From the above, only the photosensitive material of the present invention can provide good characteristics. Example 25 5 g of resin [A-22] and 35 g of resin [B-11], 200 g of zinc oxide, 0.02 g of uranine, 0.04 g of rose bengal, 0.03 g of bromophenol blue, 0.40 g of phthalic anhydride, and 300 g of toluene. a mixture of
A photosensitive material was prepared by the following operations in the same manner as in Example 22.

[0190] The photosensitive materials of the present invention were operated in the same manner as in Example 22, and their respective properties were examined. All of them had excellent chargeability, dark charge retention, and photosensitivity, and the actual copied images were also stable at high temperatures and high humidity. of(
Even under severe conditions (30° C., -80% RH), clear images without background fog were provided.

[0191] Further, when printing was performed using this as an original plate for an offset master, prints with clear image quality were obtained even after printing 10,000 copies. Examples 26 to 37 In Example 25, 5 g of resin [A-22] and resin [
B-11] Instead of 35g, use the resin [A] in Table-K below.
Each photosensitive material was produced in the same manner as in Example 25, except that 5 g of resin [B] and 35 g of resin [B] were used.

[0192]

[Table 22]

All of the photosensitive materials of the present invention have excellent chargeability, dark charge retention, and photosensitivity, and actual copied images can also be produced under high temperature and high humidity (
Even under harsh conditions (30°C, 80% RH), it provided clear images without background fog or skipped fine lines.

Furthermore, when printing was performed as an offset master original plate, printed matter with clear image quality and no scumming was obtained even after printing 10,000 sheets.

[0195]

Effects of the Invention According to the present invention, an electrophotographic photoreceptor is provided which has excellent electrostatic properties (especially electrostatic properties under severe conditions), has clear and high-quality images, and also has excellent mechanical strength. can be obtained. It is particularly effective for scanning exposure methods using semiconductor laser light.

By using a repeating unit containing a specific methacrylate component represented by formula (Ia) or (Ib) in the resin of the present invention, the electrostatic properties are further improved.

[Table 23]

Claims (3)

[Claims] Claim 1. An electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductive material, a spectral sensitizing dye, and a binder resin, wherein the binder resin comprises at least one of the following resins [A] and the following: An electrophotographic photoreceptor comprising at least one resin [B]. Resin [A] 30% by weight or more of a polymer component having a weight average molecular weight of 1 x 103 to 2 x 104 and consisting of repeating units represented by the following general formula (I), and -PO3 H2
, -SO3H, -COOH, -P(=O)(OH)R
1. A polymer component having at least one polar group selected from [R1 represents a hydrocarbon group or -OR2 (R2 represents a hydrocarbon group]] and a cyclic acid anhydride group.
A copolymer containing 5 to 15% by weight. embedded image In formula (I), a1 and a2 each represent a hydrogen atom, a halogen atom, a cyano group or a hydrocarbon group. R3 represents a hydrocarbon group. ] Resin [B] A polymer component (A) having a weight average molecular weight of 2 x 104 to 1 x 106 and consisting of repeating units represented by general formula (I) in the above resin [A] and the above resin [A] At least three polymer chains containing at least a polymer component (b) containing at least one polar group selected from the specific polar groups shown in the following are bonded to an organic molecule. 30% by weight or more of the polymer component (a) and 0.05 to 1% of the polymer component (b)
Star type copolymer containing 0% by weight. 2. The resin [A] is one of the aryl group-containing methacrylate components represented by the following general formula (Ia) and the following general formula (Ib) as the copolymer component represented by the general formula (I). The electrophotographic photoreceptor according to claim 1, characterized in that it contains at least one. [Formula 2] [Formula 3] In formulas (Ia) and (Ib), A1 and A2 are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a chlorine atom, -COR4 or -COOR4 (R4 is represents a hydrocarbon group having 1 to 10 carbon atoms, and B1 and B
2 represents a single bond or a linking group having 1 to 4 linking atoms, each of which links -COO- to a benzene ring. ] 3. In the resin [B], the total amount of the specific polar group-containing polymer component contained in the entire copolymer is
3. The electrophotographic photoreceptor according to claim 1, wherein the amount is 10% by weight to 50% by weight based on the total amount of the specific polar group-containing polymer component contained in the resin [A].