JPH04316054A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the electrophotographic sensitive body improved in electrostatic characteristics and photographing performance, especially high and precise in image reproduction performance in the case of using a liquid developer, and superior in photographic characteristics in the case of scanning exposure system using low output laser beams. CONSTITUTION:The binder resin to be used for this electrophotographic sensitive body comprises at least one of a resin A having a weight average molecular weight of 1X10<3>-2X10<4> and comprising >=30wt.% repeating units each represented by formula I and 0.5-15wt.% repeating units each having a polar group; and at least one of a resin B of an AB block copolymer having a weight average molecular weight of 2X10<4>-1X10<6> and comprising block A composed of the resin A and the block B containing repeating units each represented by formula I. In formula I, each of a<1> and a<2> is H, halogen, cyano, or a hydrocarbon group, and R<3> is a hydrocarbon group.

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. As representative electrophotographic photoreceptors, there are photoreceptors having a photoconductive layer formed on a support and photoreceptors having an insulating layer on the surface, which are widely used. 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 original 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 binder resin for the photoconductive layer that has both the electrostatic properties of an electrophotographic photoreceptor and the printing properties of a printing original plate has been developed. is necessary.

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, even if the stoichiometric defect area of the inorganic photoconductor varies slightly, it has a sufficient adsorption area, so the interaction between the inorganic photoconductor, spectral sensitizing dye, and resin is relatively stable. It is inferred that the effect is preserved.

[0006] In order to provide sufficient mechanical strength to the photoconductive layer, which is insufficient with these low molecular weight resins alone, techniques for using other medium to high molecular weight resins in combination or resins containing curable groups have 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.

[0007]

[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.

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, these An electrophotographic photoreceptor having a photoconductive layer using a combination of well-known resins is capable of faithfully copying high-definition images (particularly continuous-tone images) as described above, or is capable of producing low-power laser beams. It has become clear that the scanning exposure method used can cause problems in imaging performance.

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 with excellent electrostatic properties and low 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 that produces reproduced images that are faithful to original images (particularly high-definition continuous tone images). To provide a lithographic printing original plate which reproduces the above, does not cause not only uniform background smearing on the entire surface of printed matter but also dotted smearing, and has excellent printing durability.

[0011]

[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] has a weight average molecular weight of 1 x 103 to 2 x 104,
30% by weight or more of repeating units represented by the following general formula (I) as polymer components, -PO3 H2, -SO3
H, -COOH, -P(=O)(OH)R1 [R1
represents a hydrocarbon group or -OR2 (R2 represents a hydrocarbon group)] and a cyclic acid anhydride group.
Resin containing % by weight.

[0013]

[C4]

[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] At least one resin having an average molecular weight of 2 x 104 to 1 x 106 and containing at least one polar group selected from the specific polar groups shown in the resin [A] above. An AB block copolymer comprising an A block containing at least one polymer component and a B block containing at least a polymer component represented by the general formula (I) in the resin [A].

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 specific polar group-containing polymer component, and an A block containing the specific polar group-containing component. It is composed of at least an AB block copolymer (resin [B]) with a B block containing a polymer component represented by the above formula (I).

As a result of various studies, as mentioned above, in the known technology in which a low molecular weight polar group-containing resin is used 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, the polar group-containing block A according to the present invention and the polar group-free block were selected as medium to high molecular weight resins to be used in combination with the low molecular weight resin [A] containing polar groups. It has been found that the above problem can be effectively solved by using an AB block copolymer having B. This means that due to the synergistic effect of the binder resins [A] and [B] of the present invention, the photoconductor particles are sufficiently dispersed and exist in a non-condensed state, and the spectral sensitizing dye is present on the surface of the photoconductor particles. This is presumed to be due to the fact that the active sites on the surface of the photoconductor are sufficiently adsorbed by the binder resin and the excess active sites on the surface of the photoconductor are sufficiently adsorbed to compensate 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. In addition, the mechanical strength of the photoconductive layer was sufficiently maintained by using a medium to high molecular weight AB block copolymer composed of block A containing a specific polar group and block B not containing it. . This is because the block A part of this resin has a weaker interaction with the photoconductor particles than the resin [A] and the block B part of this resin.
This is thought to be due to the entanglement effect between the polymer chains of the moieties.

Furthermore, the fact that the electrostatic properties are more improved than the known medium to high molecular weight resins used in combination is that the block A portion that interacts with the photoconductor particles has polarity. It is thought that it functions to suppress the adsorption and alienation of spectral sensitizing dyes. This effect is caused by near-infrared light
Particularly remarkable effects were shown with polymethine dyes or phthalocyanine pigments, which are particularly effective as dyes for spectral sensitization of 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 desensitized in the non-image area by chemical treatment 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, the low molecular weight resin [A] has a specific substituent at the 2-position and/or at the 2-position and the 6-position, as shown by the following general formula (Ia) and general formula (Ib). The resin [A] contains a methacrylate component with a specific substituent containing a benzene ring or an unsubstituted naphthalene ring, and an acidic group component (hereinafter, this low molecular weight product is particularly referred to as resin [AA]). is preferred.

[0022]

[C5]

[0023]

[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 are each -C
Represents a single bond or a linking group having 1 to 4 linking atoms that connects OO- and a benzene ring. ]The above specific resin [AA]
By using this resin, 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 unknown, but one reason is that the planar benzene ring or naphthalene ring with a substituent at the ortho position, which is the ester component of methacrylate, causes these to form at the zinc oxide interface in the film. This is thought to be due to proper arrangement of 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.

If the molecular weight of the resin [A] is less than 1×10 3 , the film-forming ability decreases and sufficient film strength cannot be maintained, whereas if the molecular weight is greater than 2×10 4 , even if the resin of the present invention is used, In particular, for photoreceptors using near-infrared to infrared spectral sensitizing dyes, fluctuations in dark decay retention and light sensitivity become somewhat large under harsh conditions of high temperature, high humidity, low temperature and low humidity, resulting in stable copying. When an image is obtained, the effect of the present invention is diminished. The proportion of the polymer component corresponding to the repeating unit of general formula (I) in the resin [A] is 30% by weight
As mentioned above, the proportion of the copolymer component containing polar groups is preferably 50 to 97% by weight, and 0.5 to 15% by weight, preferably 1 to 10% by weight. If the polar group content in the resin [A] is less than 0.5% by weight, the initial potential will be low and sufficient image density will not be obtained. On the other hand, if the 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) which is contained in the resin [A] in an amount of 30% by weight or more, R3 represents a hydrocarbon group, specifically an alkyl group, It represents 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. Further, R3 preferably represents an optionally substituted hydrocarbon group having 1 to 18 carbon atoms. 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 methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, hexadecyl group, octadecyl group) and the like. Preferred hydrocarbon groups include optionally substituted alkyl groups having 1 to 18 carbon atoms (e.g., 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 (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), group, bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), optionally substituted alicyclic groups having 5 to 8 carbon atoms (for example, cyclohexyl group, 2 -cyclohexylethyl group, 2-cyclopentylethyl group, etc.) or carbon number 6
~12 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, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecoylamidophenyl group, etc. ) etc. In the hydrocarbon group represented by R3, when R3 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. In the repeating unit of the general formula (I) which is a component having such a substituent R3, more preferably the repeating unit of the general formula (Ia)
and/or a polymer component having repeating units represented by general formula (Ib).

In formula (Ia), preferable 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 -COO-
and a single bond connecting the benzene ring or -(CH2)a
- (a represents an integer from 1 to 3), -CH2OCO-
, -CH2 CH2 OCO-, -(CH2)b -
(b represents an integer of 1 or 2), -CH2 CH2
A linking group having 1 to 4 linking atoms such as O-, more preferably a single bond or a linking group having 1 to 2 linking 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.

[0030]

[C7]

[0031]

[Chemical formula 8]

[0032]

[Chemical formula 9]

[0033]

[Chemical formula 10]

[0034]

[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)(O
H) R1 represents a group represented by the following formula 12, where R1 is 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 (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a 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), and R2 represents the same content as R1.

[0036]

[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, and cyclopentane-
1,2-dicarboxylic anhydride ring, cyclohexane-1,
2-dicarboxylic anhydride ring, cyclohexene-1,2-
Dicarboxylic acid anhydride ring, 2,3-bicyclo [2.2.2
] Octadicarboxylic acid anhydride rings, etc., and these rings may be substituted with, for example, halogen atoms such as chlorine atoms or bromine atoms, or alkyl groups such as methyl groups, ethyl groups, butyl groups, hexyl groups, etc. good.

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] is, for example, the general formula (I) [
Any vinyl compound containing the polar group that can be copolymerized with the monomer corresponding to the repeating unit represented by general formulas (Ia) and (Ib)] may be used. "Polymer Data Handbook [Basic Edition]"
It is described in 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-promo 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, vinyl group or allyl group of dicarboxylic acids. Examples include ester derivatives, ester derivatives of these carboxyl or sulfonic acids, and compounds containing the polar group in a substituent of an amide derivative.

Examples of copolymerizable components containing polar groups 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.

[0040]

[Chemical formula 13]

[0041]

[Chemical formula 14]

[0042]

[Chemical formula 15]

[0043]

[Chemical formula 16]

[0044]

[Chemical formula 17]

[0045]

[Chemical formula 18]

[0046]

[Chemical formula 19]

[0047]

[C20]

[0048]

[C21]

[0049]

[C22]

[0050]

[C23]

[0051]

[C24]

[0052] Furthermore, the low molecular weight resin [A] includes monomers of general formulas (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 methacrylic acid esters containing substituents other than those described in general formula (I),
In addition to acrylic esters and crotonic esters,
α-olefins, vinyl carboxylates or allyl esters (e.g., as carboxylic acids, acetic acid, propionic acid, butyric acid, valeric acid, benzoic acid, naphthalenecarboxylic acid, etc.)
, acrylonitrile, methacrylonitrile, vinyl ethers, itaconic acid esters (e.g. dimethyl ester, diethyl ester, etc.), acrylamides, methacrylamides, styrenes (e.g. styrene, vinyltoluene, chlorostyrene, hydroxystyrene, N,N
-dimethylaminomethylstyrene, methoxycarbonylstyrene, methanesulfonyloxystyrene, vinylnaphthalene, etc.), vinyl sulfone-containing compounds, vinyl ketone-containing compounds, heterocyclic vinyls (e.g. 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 200°C.

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. The resin [B] is an AB block copolymer, and the amount of the specific polar group-containing component in the block copolymer [B] is preferably 0.1 per 100 parts by weight of the copolymer [B].
It is contained in a proportion of ~5 parts by weight, more preferably 0.2 to 3 parts by weight. The polar group content in the binder resin [B] is 0
．． If it is less than 1% by weight, the initial potential will be low and sufficient image density cannot be obtained, and if the polar group content is more than 5% by weight, dispersibility will decrease and 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.

[0055] In the resin [B], the total amount of the specific polar group-containing polymer component contained in all the copolymers is greater than the specific polar group-containing polymer component contained in the resin [A]. The amount is preferably 10% by weight to 50% by weight based on the total amount. If the total amount in the resin [B] is less than 10% by weight of that in the resin [A], the electrophotographic properties (especially charge retention in the dark and photosensitivity will be significantly reduced, and the strength of the film will also be reduced. If it exceeds % by weight, the uniformity of dispersion becomes insufficient, the electrophotographic properties deteriorate, and the water retention property as an offset original plate decreases.The weight average molecular weight of the copolymer [B] is 2×104 to 1×
106, preferably 3 x 104 to 5 x 105.

When the molecular weight of the resin [B] is smaller than 2×10 4 , the film-forming ability decreases and sufficient film strength cannot be maintained, and when the molecular weight is larger than 1×10 6 , the effect of the resin [B] of the present invention is reduced. This results in electronic properties comparable to those of conventionally known resins. The glass transition point of the resin [B] is preferably in the range of -10°C to 100°C, more preferably 0°C to 90°C. Specific examples of the polymer component containing a specific polar group constituting the A block of the AB block copolymer (resin [B]) of the present invention include the polymer component containing a specific polar group of the resin [A] described above. The same components as the combined component can be mentioned.

[0057] Two or more types of polymerization components containing the above-mentioned specific polar groups may be contained in the A block,
In that case, the two or more types of polar group-containing components may be contained in the A block in either random copolymerization or block copolymerization. Further, a polymer component other than the polar group-containing polymer component described above may be contained in the block A, and such a polymer component is preferably a polymer component corresponding to a repeating unit of the following general formula (II). can be mentioned.

[0058]

[C25]

[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-, -C
ONHCONH- or -C6H4- (where Q2 represents a hydrogen atom or a hydrocarbon group). Q1
represents a hydrocarbon group. m1 and m2 may be the same or different from each other, and a1 and a2 in the above formula (I)
and represent the same content. ]

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 (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a 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 (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), group, bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), optionally substituted alicyclic groups having 5 to 8 carbon atoms (for example, 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, ethoxy carboxyphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecoylamidophenyl group, etc.).

[0061] 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 the polymer component that can be contained in the A block together with the polymer component represented by formula (II), monomers corresponding to other repeating units that can be copolymerized with the polymer component of formula (II), e.g. acrylonitrile, methacrylonitrile,
Heterocyclic vinyls (e.g. vinylpyridine, vinylimidazole, vinylpyrrolidone, vinylthiophene, vinylpyrazole, vinyldioxane, vinyloxazine, etc.)
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 components of the A block.

Next, the polymer components constituting the B block component in the AB block copolymer [B] will be explained in detail. The B block component has at least the general formula (I
), and the component represented by formula (I) preferably accounts for 30 to 100% by weight, more preferably 50 to 10% by weight of the B block component.
Contains 0% by weight. The specific contents of the components of general formula (I) are the same as those explained for resin [A]. Other polymer components that may be contained include those similar to those described as the component represented by general formula (II) or other components that may be contained in block A. However, block B is characterized in that it does not contain the specific polar group-containing component contained in block A.

The AB block copolymer [B] of the present invention is:
It can be produced by a conventionally known polymerization reaction method. Specifically, in the monomer corresponding to the polymer component containing the specific polar group, the polar group is previously protected as a functional group, and an organometallic compound (for example, alkyl lithiums, lithium diisopropylamide, alkyl magnesium After synthesizing an AB block copolymer using a known so-called living polymerization reaction such as an ionic polymerization reaction using a hydrogen iodide/iodine system (halides, etc.), a photopolymerization reaction using a porphyrin metal complex as a catalyst, or a group transfer polymerization reaction. , a method of forming a polar group by deprotecting a functional group with a protected polar group by a hydrolysis reaction, a hydrogenolysis reaction, an oxidative decomposition reaction, a photolysis reaction, etc. can be mentioned. One example is shown in reaction scheme (1) below.

[0065]

[C26]

These include, for example, P. Lutz, P. M
asson etal, Polym. Bull. 12
．． , 79 (1984), B. C. Anderson, G.
．． D. Andrews etal, Macromol
ecules, 14, 1601 (1981), K. Ha
tada, K. Ute. etal, Polym. J. 1
7, 977 (1985), 18, 1037 (1986)
, Koichi Miguchi, Koichi Hatada, Polymer processing, 36, 366 (1
987), Toshinobu Higashimura, Mitsuo Sawamoto, Collection of Polymer Papers, 46,
189 (1989), M. Kuroki, T. Aida
, J. Am. Chem. Soc. 109, 4737 (1
987), Takuzo Aida, Shohei Inoue, Synthetic Organic Chemistry, 43,
300 (1985), D. Y. Sogah, W. R. H
ertleretal. Macromolecules
, 20, 1473 (1987) and the like.

Furthermore, the AB block copolymer [B] uses a monomer with its polar group unprotected and uses 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, Kobunshi, 37, 248 (1988), Shunichi Himori, Ryuichi Otsu, P.
olym. Rep. Jap. 37.3508 (1988
), JP-A-64-111, JP-A-64-26619, Higashi Nobuyuki et al., Polymer Preprints,
Japan, 36, (6), 1511 (1987), M
．． Niwa, N. Higashi, etal, J. Ma
cromol. Sci. Chem. A24(5), 56
7 (1987) and others.

Regarding the protection of a specific polar group of the present invention with a protecting group and the removal of the protecting group (deprotection reaction),
This can be easily done using conventionally known knowledge. For example, there are various descriptions in the cited documents, and furthermore,
Yoshio Iwakura, Keisuke Kurita, "Reactive Polymer" Kodansha Co., Ltd. (1977), T. W. Greene, “Prote
Active Groups in Organi
John Wiley
& Sons (1981), J. F. W. Mc
Omie, “Protective Groups
in Organic Chemistry”Ple
num Press, (1973) and the like can be suitably selected. Furthermore, block A can be obtained by synthesizing an azobis compound (i.e., polymeric azobis initiator) containing any part of block B, and using this as an initiator, the monomer equivalent to forming the other block is synthesized. It is also possible to use a method of synthesizing the class by a radical polymerization reaction.

Specifically, it can be synthesized by the method described in Akira Ueda, Susumu Nagai, Collection of Kobunshi Ronsen, 44, 469 (1987), Akira Ueda, Osaka City Industrial Research Institute Report, 84 (1989), etc. Can be done. When synthesizing using this reaction, the weight average molecular weight of the polymer azobis initiator should be 2 x 104 or less due to the ease of synthesis of the polymer azobis initiator and the regularity of the blocking polymerization reaction. preferable. On the other hand, in the resin [B] of the present invention, it is preferable that block B has a longer polymer chain than block A. From the above, when synthesizing by this reaction, a method using a block A-containing polymer initiator is preferable. For example, the reaction can be carried out using the reaction scheme (2) shown below.

[0070]

[C27]

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, acrylate copolymer, and 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 the binder resin used in the photoconductive layer of the present invention is preferably 10 parts by weight to 100 parts by weight based on 100 parts by weight of the inorganic photoconductor.
More preferably, it is 15 parts by weight to 50 parts by weight.

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

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. As the spectral sensitizing dye used in the present invention, various dyes may be used alone or in combination, if necessary. For example, Harumi Miyamoto, Hidehiko Takei, Imaging 1973 (No. 8) p. 12, C. J
．． Young et al., RCA Review 15, 4
69 (1054), Wataru Kiyota, Transactions of the Institute of Electrical Communication Engineers J
63-C (No. 2), 97 (1980), Yuji Harasaki et al., Industrial Science Magazine 66 78 and 188 (1963
), Tadaaki Tani, Journal of the Photographic Society of Japan 35, 208 (1972)
Carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein dyes, polymethine dyes (e.g., oxonol dyes, merocyanine dyes, cyanine dyes, rhodacyanine dyes, styryl dyes, etc.), phthalocyanine dyes ( may contain metal), etc.

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 No. 3,052,540, U.S. Patent No. 4,054,4
50, JP-A-57-16456, and the like. Examples of polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes, and rhodacyanine dyes include F. M. Hammer “The Cyan”
ineDyes and Related Co.
The dyes described in U.S. Pat. No. 3,047,384, U.S. Pat. No. 3,125,447, No. 3,128,179,
British Patent No. 3,132,942, British Patent No. 3,622,317, British Patent No. 1,226,892, British Patent No. 1,309,
No. 274, No. 1,405,898, Special Publication No. 1974-7
Examples include dyes described in No. 814 and No. 55-18892.

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 issue, “Research
Disclosure” 1982, 216, 117
Examples include those described on pages 118 to 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 also be used in combination. For example, the aforementioned review article: Imaging 1973 (No. 8) p. ``Development and practical application of photoconductive materials and photoreceptors'', Chapters 4 to 6, Nihon Kagaku Information Co., Ltd. Publishing Department (1986), cites polyarylalkane compounds, hindered phenol compounds, and p-phenylene. Examples include diamine compounds.

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. In addition, 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~
1μ, especially 0.05 to 0.5μ is suitable. In some cases, an insulating layer is added mainly for the purpose of protecting the photoreceptor, improving its durability, dark decay characteristics, etc. At this time, the insulating layer is set to be relatively thin, and when the photoreceptor is used 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 between 5 and 70μ, in particular 1
It is set to 0 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 preferably 5 to 40 microns, particularly 10 to 30 microns. Typical resins used to form the insulating layer or charge transport layer include polystyrene resin, polyester resin, cellulose resin, polyether resin,
Thermoplastic resins and effective resins such as vinyl chloride resin, vinyl acetate resin, vinyl chloride acid vinyl 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 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.
A water-resistant adhesive layer is provided on the surface of the support, a pre-coat layer of at least one phase is provided as required on the surface layer of the support, and a conductive plastic substrate on which Al or the like is vapor-deposited is used as paper. You can use a laminated one.

Specifically, examples of conductive substrates or conductive materials include 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 in both the PPC system and the CPC system, and can be used in combination with either a dry developer or a liquid developer. 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 can be applied not only to black and white copy images but also to color copy images (for example, Kuro Takizawa, ``
Photo Industry" 33, 34 (1975), Masayasu Anzai, "Methods described in Institute of Electronics and Communication Engineers Technical Research Report 77, 17 (1977), etc.).

Furthermore, the present invention is also effective in systems for other applications 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, or as a photoreceptor using photoconductive zinc oxide or photoconductive titanium oxide, which is non-polluting and has good whiteness. The body can be used as a marking material for a draft or a color proof used in an offset printing process.

[0081]

[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] After heating a mixed solution of 95 g of benzyl methacrylate, 5 g of acrylic acid, and 200 g of toluene to a temperature of 90°C under a nitrogen stream, 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.

[0082]

[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]. Mw of each resin [A] is 5.0×103 to 9.0×10
It was 3.

[0084]

[Table 1]

[0085]

[Table 2]

[0086]

[Table 3]

[0087]

[Table 4]

[0088]

[Table 5]

[0089]

[Table 6]

[0090]

[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] 100 g of methyl methacrylate and 200 g of tetrahydrofuran
The mixed solution of g was thoroughly degassed under a nitrogen stream and cooled to -20°C. 1,1-diphenylbutyllithium 0.8g
was added and reacted for 12 hours. Furthermore, a mixed solution of 60 g of methyl acrylate, 6 g of triphenylmethyl methacrylate, and 5 g of tetrahydrofuran was added to this mixed solution after sufficiently degassing under a nitrogen stream, and the mixture was reacted for further 8 hours. After the mixture was cooled to 0° C., 10 ml of methanol was added and reacted for 30 minutes to terminate the polymerization. The resulting polymer solution was brought to a temperature of 30° C. while stirring, and 3 ml of a 30% hydrogen chloride ethanol solution was added thereto and stirred for 1 hour. next,
The solvent was distilled off from the reaction mixture under reduced pressure until the total volume was reduced to half, and then reprecipitated into 1 liter of petroleum ether. The precipitate was collected and dried under reduced pressure, and the Mw of the polymer obtained was 7.3 x 104, and the yield was 72 g.

[0093]

[C29]

Synthesis Example 2 of Resin [B]: [B-2] 70 g of methyl methacrylate: 30 g of methyl acrylate (tetraphenylporphinate) aluminum methyl 0.
A mixed solution of 5 g and 60 g of methylene chloride was brought to a temperature of 30° C. under a nitrogen stream. This was irradiated with 300 W xenon lamp light from a distance of 25 cm through a glass filter, and reacted for 12 hours. Further, 60 g of methyl acrylate and 3.2 g of benzyl methacrylate were added to this mixture, and after irradiation with light for 8 hours, 3 g of methanol was added to this reaction mixture and stirred for 30 minutes to stop the reaction. Next, Pd-C was added to this reaction mixture, and 1
A time catalytic reduction reaction was performed. After filtering out insoluble matter, the mixture was reprecipitated into 500 ml of petroleum ether, and the precipitate was collected and dried. The obtained polymer had a yield of 118 g and a Mw of 8×104.
Met.

[0095]

[C30]

Synthesis Example 3 of Resin [B] [B-3] A mixed solution of 100 g of ethyl methacrylate and 200 g of toluene was sufficiently degassed under a nitrogen stream and cooled to 0°C. Then, 2.5 g of 1,1-diphenyl-3-methylpentyllithium was added and stirred for 6 hours. Furthermore, 60 g of methyl methacrylate and 4.6 g of 4-vinylphenyloxytrimethylsilane were added to this mixture, and the mixture was stirred for 6 hours, and then 3 g of methanol was added and stirred for 30 minutes. Next, 10 g of a 30% hydrogen chloride ethanol solution was added to this reaction mixture, and the mixture was stirred at 25° C. for 1 hour. The precipitate was reprecipitated into 1 liter of methanol, and the collected precipitate was washed twice with 300 ml of methanol and dried. The obtained polymer had a yield of 121 g and a Mw of 6.
It was 5×104.

[0097]

[Chemical formula 31]

Synthesis Example 4 of Resin [B]: [B-4] A mixture of 67 g of methyl methacrylate and 4.8 g of benzyl N,N-diethyldithiocarbamate was sealed in a container under a nitrogen stream and heated to a temperature of 50 g. did. This was irradiated with light for 6 hours using a 400 W high-pressure mercury lamp from a distance of 10 cm through a glass filter for photopolymerization. After adding 32 g of methyl acrylate, 1 g of acrylic acid, and 180 g of methyl ethyl ketone, the mixture was purged with nitrogen and irradiated with light for 10 hours again. The obtained reaction product was reprecipitated in 1 liter of methanol, collected and dried. The obtained polymer had a yield of 73 g and a Mw of 4.8×
It was 104.

0099

[C32]

Synthesis Example 5 of Resin [B]: [B-5] 50 g of methyl methacrylate, 25 g of ethyl methacrylate,
A mixture of 1.0 g of benzyl isoprusanthate was sealed in a container under a nitrogen stream and heated to a temperature of 50°C. This was irradiated with light from a 10 cm distance through a glass filter for 6 hours using a 400 W high-pressure mercury lamp for photopolymerization. This polymer was made into a solution with a concentration of 40% in tetrahydrofuran, 22 g of methyl acrylate was added thereto, the atmosphere was replaced with nitrogen, and the solution was again irradiated with light for 10 hours. Then add 2-(2'
-carboxyethyl) carbonyloxyethyl methacrylate (3 g) was added, the atmosphere was again replaced with nitrogen, and the mixture was again irradiated with light for 8 hours. The obtained reaction product was reprecipitated in 2 liters of methanol, and the collected powder was dried. The obtained polymer had a yield of 63 g and a Mw of 6 x 104.

[0101]

[Chemical formula 33]

Synthesis Example 6 of Resin [B]: [B-6] A mixed solution of 97 g of ethyl acrylate, 3 g of methacrylic acid, 2 g of 2-mercaptoethanol and 200 g of tetrahydrofuran was heated to 60° C. with stirring under a nitrogen stream. . To this, 2,2'-azobisisovaleronitrile (A
．． I. V. N. ) was added and reacted for 4 hours, and then A
．． I. V. N. 0.5 g was added and reacted for 4 hours.

After bringing the reaction mixture to a temperature of 20°C, 4
, 4'-azobis(sia)valeric acid) 8.6 g, dicyclohexyldicarbodiimide 12 g, 4-(N,N-dimethyl)pyridyl 0.2 g and tetrahydrofuran 30 g
A mixed solution of was added dropwise over 1 hour. After further stirring for 2 hours, 5 g of 85% formic acid aqueous solution was added and further stirred for 30 minutes. Next, after separating the precipitated crystals by filtration, the filtrate was collected at a temperature of 25
The solvent was distilled off under reduced pressure at °C. The Mw of the obtained polymer (polymer initiator) having the following structure was 6.3×10 3 .

[0104]

[C34]

[0105] A mixed solution of 70 g of methyl methacrylate and 170 g of toluene was heated to a temperature of 70% while stirring under a nitrogen stream.
Warmed to ℃. To this, add 30g of the above polymer to 33g of toluene.
After replacing the solution with 0 g of nitrogen in advance, the solution was added and reacted for 8 hours. The obtained polymer was reprecipitated in 2 liters of methanol, and the collected powder was dried. The yield of the obtained polymer was 72 g, and the Mw was 4 x 104.

[0106]

[C35]

Synthesis example 7/16 of resin [B]: [B-7]
~ [B-16] Using the same reaction method as in Synthesis Example 3 of resin [B], the following table-B
Resin [B] shown below was synthesized. Mw of the obtained copolymer
was in the range of 5 x 104 to 9 x 104.

[0108]

[Table 8]

[0109]

[Table 9]

[0110]

[Table 10]

Synthesis Examples 17 to 23 of Resin [B]: [B-1
7] ~ [B-23] Using the same reaction method as in Synthesis Example 4 of resin [B], the following table-C
Resin [B] shown below was synthesized. Mw of the obtained copolymer
was in the range of 4 x 104 to 8 x 104.

[0112]

[Table 11]

[0113]

[Table 12]

Example 1 Resin [A-7] 6g (as solid content), Resin [B-1]
] 34g (as solid content), photoconductive zinc oxide 200
g, a mixture of 0.018 g of cyanine dye [I] having the following structure, 0.15 g of phthalic anhydride, and 300 g of toluene was heated in a homogenizer (manufactured by Nippon Seiki Co., Ltd.) at a rotation speed of 6 x 10.
A photosensitive layer-forming product was prepared by dispersing at 3 rpm for 10 minutes, and the dry adhesion amount was 22 g/m2.
An electrophotographic light-sensitive material was prepared by coating with a wire bar, drying at 110° C. for 10 seconds, and then leaving in a dark place at 20° C. and 65% RH for 24 hours.

[0115]

[C36]

Comparative Example 1 Example 1 was repeated except that 34 g of resin [R-1] having the following structure was used instead of 34 g of resin [B-1].
An electrophotographic light-sensitive material was prepared in the same manner as above.

[0117]

[C37]

Comparative Example 2 An electrophotographic light-sensitive material was prepared in the same manner as in Example 1, except that 34 g of resin [B-1] was replaced with resin [R-2] having the following structure. did.

[0119]

[C38]

[0120] Regarding these photosensitive materials, electrostatic properties, imaging properties, and environmental conditions (20°C, 65% RH) and (30°C)
℃, 80% RH) was investigated. The above results are shown in Table-D.

[0121]

[Table 13]

[0122] The implementation of the evaluation items shown in Table D is as follows. Note 1) Electrostatic properties: In a dark room at a temperature of 20°C and 65% RH.
-6k using a paper analyzer (Paper Analyzer SP-428 model manufactured by Kawaguchi Electric Co., Ltd.) for each photosensitive material.
After performing corona discharge at V for 20 seconds, it was left to stand for 10 seconds, and the surface potential V10 at this time was measured. Next, the potential V100 was measured after leaving it to stand still in the dark for 90 seconds.
The retention of the potential after dark decay for 0 seconds, that is, the dark decay retention rate [DRR (%)] is (V100 /V10) x 10
It was calculated as 0 (%).

[0123] Furthermore, the surface of the photoconductive layer is 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, 65% RH (I), and 3
The test was carried out at 0° C. and 80% RH (II).

Note 2) Imaging properties: 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 semiconductor laser (with an output of 2.8 mW) was used as a light source. Using an oscillation wavelength of 780 nm), the radiation dose was 64 erg/cm2 on the surface of the photosensitive material, the pitch was 25 μm, and the scanning speed was 300 m/s.
ELP-T (
The reproduced image (fogging, image quality) obtained by developing it using Fuji Photo Film Co., Ltd. and washing and fixing it with isoparaffin Isopar G (Shell Chemical Co., Ltd.) solvent rinse solution. Visual evaluation was performed.

[0125] The environmental conditions at the time of imaging were 20°C, 65% RH (I
) and 30°C and 80% RH (II). As shown in Table D, 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. Further, although it does not match the electrostatic characteristics, unevenness occurred in the intermediate density of the continuous tone portion of the copied original. The E1/100 value differs greatly between the photoreceptor of the present invention and the photoreceptor of the comparative example. E1/
The 100 value indicates how much potential remains in the non-image area (already exposed area) after exposure in actual imaging performance, and the smaller this value is, the greater the potential in the non-image area after development. Indicates that scumming will not occur.

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 has been revealed that only when the resin of the present invention is used, an electrophotographic photoreceptor that satisfies electrostatic properties and imaging performance can be obtained, and is especially advantageous for photoreceptor systems using semiconductor laser beam scanning exposure.

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.

[0128]

[C39]

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. The results are shown in Table E.

[0130]

[Table 14]

[0131] The implementation of the evaluation items shown in Table E 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 the surface of the photoconductive layer is desensitized by passing it through, 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: A toner image is formed by plate making under the same conditions as the imaging performance in Note 2) above.
The desensitization process was carried out under the same conditions as the above, and this was used as an offset master to run on an offset printing machine (Oliver Model 52 manufactured by Sakurai Seisakusho Co., Ltd.), so that there would be no background smudges in the non-image areas of the printed matter and no problems with the image quality in the image areas. indicates the number of sheets that can be printed (the larger the number of sheets printed, the better the printability). Table -
As shown in E, in the photosensitive material of the present invention, 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 is presumed to be due to the photoconductor and the binder resin being sufficiently adsorbed and covering 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.

[0133] The above describes the resin [A] and the resin [
B] appropriately interacts with the zinc oxide particles, forming a state in which the desensitization reaction by the desensitization treatment liquid can easily and sufficiently proceed, and film strength due to the action of the resin [B]. This shows that a significant improvement has been achieved.

Examples 3 to 18 Resin [A-3] and resin [B-2] in Example 2 were replaced with each resin [A] and each resin [B] in Table-F below. Each electrophotographic photoreceptor was produced in the same manner as in Example 2. Electrostatic properties were measured in the same manner as in Example 2. The results are shown in Table-F.

[0135]

[Table 15]

Further, when the actual imaging performance of these photosensitive materials was investigated, the reproducibility of fine lines and characters was good, and there was no occurrence of unevenness in intermediate tones. A clear copy image with no background fog was obtained.

Examples 19 to 22 Electrophotographic photoreceptor 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 dye shown in Table G below.

[0138]

[Table 16]

[0139]

[Table 17]

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 Resin [
A-1] (Example 23) or resin [A-29] (Example 24) 6.5 g, resin [B-9] 33.5 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 in a homogenizer. and rotation speed 7×103 r. P. M. Dispersion was carried out for 10 minutes to prepare a photosensitive layer-formed product, which was coated on electrically conductive treated paper with a wire bar so that the dry adhesion amount was 20 g/m2, and dried at 110 DEG C. for 20 seconds. Next, each electrophotographic photoreceptor was prepared by leaving it for 24 hours in a dark place at 20° C. and 65% RH.

[0142]

[C40]

[0143]

[C41]

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-2] in Example 23.

[0145]

[C42]

[0146] In the same manner as in Example 1, the characteristics of each photosensitive material were investigated. The results are summarized in Table H below.

[0147]

[Table 18]

[0148] 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 -400 V 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 E1/
The time required for the light to attenuate to 100 is determined, and the exposure amount E1/10 or E1/100 (lux/second) is calculated from this.

Note 7) Imageability 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 EPL-404V (manufactured by Fuji Photo Film Co., Ltd.) using EPL-T as a toner. The resulting copied image (fog, image quality) was visually evaluated. The environmental conditions during imaging were 20°C, 65% RH (I) and 30°C, 80°C.
%RH(II). However, the manuscript for copying (ie, the draft manuscript) was created by cutting out and pasting other manuscripts. No difference was observed in the smoothness and strength of the photoconductive layer among the photosensitive materials. However, in terms of electrostatic properties, Comparative Example 3 had a particularly large value of photosensitivity E1/100, which was further aggravated and deteriorated at high temperature and high humidity. The electrostatic properties of the photosensitive material of the present invention are good, and furthermore, Example 24 using the resin [A] having a specific substituent has very good properties, especially the value of E1/100 is small. . When examining the actual imaging performance, in Comparative Example 3, in addition to the original document, the frame of the cut out and pasted portion (that is, pasting trace) was observed as background stains in the non-image area. 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, 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].

Example 25 5 g of resin [A-23], 5 g of resin [B-12], 200 g of zinc oxide, 0.02 g of uranine, 0.0 g of rose bengal.
A light-sensitive material was prepared using a mixture of 0.04 g of bromophenol blue, 0.40 g of phthalic anhydride, and 300 g of toluene in the same manner as in Example 22. When the photosensitive materials of the present invention were operated in the same manner as in Example 22 and their respective properties were investigated, they were all excellent in chargeability, dark charge retention, and photosensitivity, and the actual copied images were also stable at high temperatures and high humidity (30°C). ,-80%
Even under the harsh conditions of RH), it provided clear images without background fog. Furthermore, when this was used 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-12] Instead of 35g, use the resin [A] in Table-I 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.

[0153]

[Table 19]

All of the photosensitive materials of the present invention have excellent chargeability, dark charge retention, and photosensitivity, and the actual reproduced images are also exposed to high temperatures and high humidity (
Even under harsh conditions (30°C, 80% RH), it provided clear images without background fog or skipped fine lines. Furthermore, when printed as an offset master original plate, clear prints with no background staining were obtained even after printing 10,000 sheets.

[0155]

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), provides clear and high-quality images, and has further excellent mechanical strength. can be obtained. It is particularly effective for scanning exposure methods using semiconductor laser light. Formula (Ia) or (I
By using a repeating unit containing a specific methacrylate component shown in b) in the resin of the present invention, the electrostatic properties are further improved.

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] has a weight average molecular weight of 1 x 103 to 2 x 104,
30% by weight or more of repeating units represented by the following general formula (I) as polymer components, -PO3 H2, -SO3
H, -COOH, -P(=O)(OH)R1 [R1
represents a hydrocarbon group or -OR2 (R2 represents a hydrocarbon group)] and a cyclic acid anhydride group.
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] has a weight average molecular weight of 2 x 104 to 1 x 106,
At least one polar group containing at least one kind of polar group selected from the specific polar groups shown in the resin [A] above.
A composed of an A block containing at least one polymer component and a B block containing at least a polymer component represented by the general formula (I) in the resin [A].
B block copolymer. 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].