JPH0264547A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the electrostatic characteristic of the subject body, and to reproduce a faithful copying picture against an original picture by composing a binding resin contd. in the photosensitive body of a specified copolymer. CONSTITUTION:The photoconductive layer of the photosensitive body contains at least an inorg. photoconductive material (such as zinc oxide) and the binding resin (A). The resin (A) is composed of a copolymer having a weight average mol.wt. of 1X10<3>-2X10<4> and contg. >=30wt.% of a recurring unit shown by formula I or II, and 0.5-15wt.% of a recurring unit contg. at least one of a group selected from groups comprising -PO3H2, -SO2H, -COOH, a group shown by formula III and a cyclic acid anhydride group, etc. In the formula, X1 and X2 are each hydrogen atom or 1-10 C hydrocarbon, etc., W1 and W2 are each a linking group, R is 1-10 C hydrocarbon, etc. The copolymer preferably contains 1-20wt.% of a recurring unit contg. a functional group capable of curing with heat and/or light.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having excellent electrostatic properties and moisture resistance.

In particular, it relates to a CPC photoreceptor with excellent performance.

(Prior Art) Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied.

As representative electrophotographic photoreceptors, there are photoreceptors having a photoconductive layer formed on a support and photoreceptors having an insulating layer on the surface, which are widely used.

Photoreceptors, consisting of a support and 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.

The binder 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, and also has excellent properties in the formation of the formed recording layer. It has good adhesion to the substrate, and the photoconductive layer of the recording layer has excellent charging ability, low dark decay (large light decay, little pre-exposure fatigue, and resistance to changes in humidity during imaging). Therefore, it is necessary to have various electrostatic properties such as the need to stably maintain these properties and excellent imaging performance.

Examples of resins that have been known for a long time include silicone resin (Japanese Patent Publication No. 34-6670), styrene-butadiene resin (
(Japanese Patent Publication No. 35-1960), alkyd resin, maleic acid resin, polyamide (Japanese Patent Publication No. 11219-197), vinyl acetate resin (Japanese Patent Publication No. 2425-1977), vinyl acetate copolymer (Japanese Patent Publication No. 2426-197) ,acrylic resin(
(Japanese Patent Publication No. 35-11216), acrylic acid ester copolymers (e.g., Japanese Patent Publication No. 11219/1971, Japanese Patent Publication No. 36/1982)
No. 8510, Japanese Patent Publication No. 41-13946, etc.) are known.

However, electrophotographic light-sensitive materials using these resins lack 1) affinity with the photoconductive powder, resulting in poor dispersibility of the coating solution. 2) Low chargeability of the photoconductive layer, 3
) The quality of the image area of the copied image (especially halftone reproducibility and resolution) is poor; 4) The environment at which the copied image was created (e.g. high temperature,
Low temperature? W, etc.), the image quality is easily affected.

Various methods have been proposed to improve the electrostatic properties of the photoconductive layer, and one such method is to use a compound containing a carboxyl group or a nitro group in an aromatic ring or a furan ring, or a dicarboxylic acid anhydride. Japanese Patent Publications No. 42-6878 and No. 45-3073 disclose a method of further combining materials to coexist in a photoconductive layer. but,
Even with photosensitive materials improved by these methods, their electrostatic properties are still insufficient, and none particularly excellent in light attenuation properties has been obtained. Therefore, in order to improve the lack of sensitivity of this photosensitive material, a method of adding a large amount of sensitizing dye to the photoconductive layer has been conventionally used, but the photosensitive materials produced by this method have a remarkable whiteness. This has caused problems such as deterioration of the quality of the recording medium and, in some cases, deterioration of the dark decay of the photosensitive material, making it impossible to obtain a sufficient copy image.

On the other hand, JP-A-60-10254 discloses a method of adjusting the average molecular weight of a resin used as a binder resin for a photoconductive layer. That is, an acrylic resin with an acid value of 4 to 50 and an average molecular weight distribution of 103 to 10';
A technique has been described for improving electrostatic properties (particularly repeatability as a PPC photoreceptor), moisture resistance, etc. by using together components having a distribution of 1 to 2×10 4 .

Furthermore, research is being carried out on lithographic printing original plates using electrophotographic photoreceptors, and a binder resin for the photoconductive layer that has both the electrostatic properties of an electrophotographic photoreceptor and the printing properties of a printing original plate has been developed. For example, in Japanese Patent Publication No. 50-31011, Mwl, 8 to 10
A combination of 7 g of resin at 10 to 80°C at O' and a copolymer consisting of a (meth)acrylate monomer and a monomer other than fumaric acid, and JP-A-53-54027
In this issue, a terpolymer containing a (meth)acrylic acid ester having a substituent having a carboxylic acid group separated from an ester bond by at least 7 atoms is used, and JP-A No. 5
In No. 4-20735 and JP-A No. 57-202544,
Those using quaternary or penta-component copolymers containing acrylic acid and hydroxyethyl (meth)acrylate, and those using JP-A No. 5
No. 8-68046 discloses that a terpolymer containing a (meth)acrylic acid ester having an alkyl group having 6 to 12 carbon atoms as a substituent and a carboxylic acid-containing vinyl monomer is used as an insensitive resin for the photoconductive layer. It is stated that it is effective in improving the chemical properties.

(Problem that the invention attempts to solve!!!) However, even if the resin is said to be effective in the above-mentioned electrostatic properties and moisture resistance properties, when actually evaluated, it shows that it has particularly poor chargeability and dark charge retention. However, there were problems with electrostatic properties such as photosensitivity, smoothness of the photoconductive layer, etc., and it was not practically satisfactory.

Furthermore, even in the case of a binder resin which is said to have been developed as an original plate for electrophotographic planographic printing, when actually evaluated, there were problems with the above-mentioned electrostatic properties, scumming of printed matter, moisture resistance properties, etc.

The present invention is intended to improve the above-mentioned problems of conventional electrophotographic photoreceptors.

An object of the present invention is to provide a high-quality electrophotographic photoreceptor that has improved electrostatic properties (particularly dark charge retention and photosensitivity) and reproduces copied images that are faithful to original images.

Another object of the present invention is to provide an electrophotographic photoreceptor that produces clear, high-quality images even when the environment during copy image formation fluctuates, such as low temperature and low humidity, or high and high temperatures.

Another object of the present invention is to provide a CPC electrophotographic photoreceptor with excellent electrostatic properties and low environmental dependence.

Other objects of the present invention are 1. An object of the present invention is to provide a lithographic printing plate which can be used as an electrophotographic lithographic printing original plate and which can produce printed matter that does not cause any scumming.

Another object of the present invention is to provide an electrophotographic photoreceptor that is less susceptible to the effects of the types of aggravating dyes that can be used in combination.

(Means for Solving the Problem) The above problem is an electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductive material and a binder resin, in which the binder resin has a layer of 1×10 3 to 2×10 4 . The problem is solved by an electrophotographic photoreceptor characterized by containing at least one resin having a weight average molecular weight and containing the following repeating units (i) and (11) as a copolymer component.

(i) At least one represented by formula (1) or formula (If)
30% by weight or more formula ('Q)
co.

(In the formula, X and Xt are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a chlorine atom, a bromine atom,
-COY or -COOY! (Y + and Y2 each represent a hydrocarbon group having 1 to 10 carbon atoms).

However, both Xl and X2 do not represent hydrogen atoms. and 6 bond -COO- to the benzene ring,
Represents a direct bond or a linking group having 1 to 4 linking atoms.

(it) JQst1g group, -3O311 group, -C0
OH group, -P-0) 1 group (R is a hydrocarbon group having 1 to 10 carbon atoms or -OR'(R' is a hydrocarbon group having 1 to 1 o carbon atoms), -3H group and At least one of the acidic group and the cyclic acid anhydride-containing group of the phenolic OH group
at least one repeating unit containing 0 substituents
．． 5-15% by weight.

Furthermore, when the resin contained in the binder resin further contains the following repeating units (ui) as a copolymerized component in addition to the above repeating units (i) and (ii), the film strength is further improved. It was found that an electrophotographic photoreceptor having excellent printing durability could be obtained.

(iii) 1 to 20% by weight of at least one repeating unit containing a thermally and/or photocurable functional group;
Two or more types of each of the above repeating units (i), (ii), and (iii) may be contained in the binder resin.

The conventionally known acidic group-containing binder resins as described above are mainly used for offset masters, and have a large molecular weight (for example, 5XIO' or more) in order to maintain film strength and thereby improve rigidity resistance.

On the other hand, resins containing acidic groups and/or cyclic acid anhydride-containing groups containing methacrylate copolymer components with specific substituents (hereinafter referred to as acidic groups unless otherwise specified) are used in the present invention. (including cyclic acid anhydrides)
Because the acidic groups contained in the resin are adsorbed to the stoichiometric defects of the inorganic photoconductor and it is a low molecular weight substance,
It was discovered that improving the coverage of the photoconductor surface compensates for photoconductor trapping and dramatically improves humidity characteristics, while also ensuring sufficient dispersion of the photoconductor and suppressing agglomeration. Ta.

Furthermore, the surface of the photoconductor becomes smooth.

When a photoreceptor with a rough surface of the photoconductive layer is used as an electrophotographic lithographic printing original plate, the dispersion state of the photoconductor particles and the binder resin may not be appropriate, and the photoconductive layer may be damaged in the presence of aggregates. As a result, even if desensitization treatment is performed using a desensitization treatment liquid, the non-image area cannot be made uniformly and sufficiently hydrophilic.
This causes adhesion of printing ink during printing, resulting in background smudges in non-image areas of printed matter.

On the other hand, due to the lower molecular weight of the binder resin according to the present invention, there was a concern that the strength of the film would weaken. It has been found that the film has sufficient film strength for use as a CPC photoreceptor or as an offset original plate for printing several tens of sheets.

Furthermore, the resin of the present invention further contains at least 11 thermally and/or photocurable functional groups! ! It has been found that when the functional group is contained, the functional group appropriately crosslinks the polymers, thereby strengthening the interaction between the polymers and improving the strength of the membrane. Therefore, the resin of the present invention further containing a heat-curable and/or photo-curable functional group can further improve the mutual interaction between the binder resin and the inorganic photoconductor particle surface without impeding proper adsorption and coating of the binder resin. This has the effect of strengthening the action and, as a result, improving the film strength.

The weight average molecular weight of the binder resin is 1 x 103 to 2.
x 104, preferably 5 x 103 to 1 x 103, the proportion of the copolymer component (i) corresponding to the repeating unit of formula (1) or formula ([1)] is 30% by weight or more, preferably 50% by weight. ~97% by weight, and the proportion of the copolymer component (ii) containing the acidic group is 0.5 to 15% by weight, preferably 1 to 10% by weight, and the nuclear heat and/or photocurable functional When the group-containing copolymer component (iii) is present, its proportion is 1 to 20% by weight. The glass transition temperature of the resin is preferably between -10"C and 100"C.
More preferably, the temperature is -5°C to 80''C.

If the molecular weight of the binder resin is smaller than 1X10'', film formation will decrease and sufficient film strength cannot be maintained;
If it is larger than XIO', electrophotographic characteristics (especially initial potential and dark decay retention) will deteriorate, which is not preferable. Particularly in the case of such a polymer, if the acidic content exceeds 3%, the electrophotographic properties deteriorate significantly, and when used as an offset master, background smudge becomes noticeable.

If the acidic group content in the binder resin is less than 0.5% by weight, the initial potential will be low (and sufficient image density cannot be obtained).On the other hand, if the acidic group content is more than 15% by weight, the dispersion will be poor. The film smoothness and high-temperature electrophotographic properties are reduced, and when used as an offset master, background smearing increases.

Furthermore, when heat and/or photocurable functional groups are present in the binder resin, if the content is less than 1% by weight, the curing reaction is insufficient and the effect of improving film strength due to the curable functional groups cannot be obtained. On the other hand, if the content of the functional group is more than 20% by weight, the degree of curing of the film becomes too high, resulting in poor electrophotographic properties, and furthermore, background smearing increases when used as an offset master, which is not preferable.

30% by weight as a copolymer component in the binder resin of the present invention
The repeating unit (i) contained above is represented by the above formula (1) or (II).

In formula (1), preferred X and X! In addition to hydrogen atoms, chlorine atoms, and bromine atoms, preferred hydrocarbon groups include alkyl groups having 1 to 41 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, etc.), and 7 to 9 carbon atoms. Aralkyl groups (e.g. benzyl group, phenethyl group, 3-phenylzolovyl group, chlorobenzyl group, dichlorobenzyl group, bromobenzyl group, methylbenzyl group, methoxybenzyl group, chloro-methyl-benzyl group, etc.), aryl groups (e.g. phenyl group, tolyl group,
xyl group, bromophenyl group, methoxyphenyl group, chlorophenyl group, dichlorophenyl group, etc.), -COY, and -COOY! (Preferred Yl and Y8
Examples of the hydrocarbon group include those described above as preferred hydrocarbon groups. however,
Xl and X! Both do not represent a hydrogen atom.

In formula (1), -1 is a direct bond connecting -coo- and a benzene ring, or (CL)- (n represents an integer of 1 to 3), -CHlCHJCO-(CHtO)-
(m represents an integer of 1 or 2), -cHzcuto
- represents a linking group having 1 to 4 linking atoms, such as -.

- and - in formula (■) represent the same content as -.

Specific examples of the repeating unit (i) represented by formula (1) or (I[) used in the present invention are listed below. but,
The scope of the present invention is not limited thereto.

1-1) C113i-2) C! 13 i-6) H1 H3 i-7) i-4) C1l.

i-9) C11゜ ShitllLr&tls i-10) i-11) i-19) i-20) i-21) CH3・ CH3 CH.

CH.

II3 1h C11゜ Shii3 i-14) i-15) i-16) i-17) i-22) i-23) i-24) i-25) CH3 C.I.

CH3 Ha HI C1(.

CH3 H3 i-26) i-35) i-36) i-37) ShiULIs i-30) ＋　CHz−＾mo + -38) i-40) Moreover, in the resin (A) of the present invention "Acidic group repeating unit (ii) containing The new acidic group is -POJg group, fhH In ``, -COOH group, Like -P-OH group, It is a cyclic acid anhydride-containing group.

In the R-1-oH group, R represents a hydrocarbon group or IOR'011'(R' represents a hydrocarbon group), and R and R' preferably represent an aliphatic group having 1 to 22 carbon atoms (e.g. , methyl group, ethyl group, purpyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, 2-chloroethyl group, 2-methoxyethyl group, 3
-ethoxypropyl group, allyl group, crotonyl group, butenyl group, cyclohexyl group, benzyl group, phenethyl group, 3-phenylpropyl group, methylbenzyl group, chlorobenzyl group, fluorobenzyl group, methoxybenzyl group, etc.), or substituted optional aryl groups (e.g., phenyl group, tolyl group, ethylphenyl group, propylphenyl group, chlorophenyl group, fluorophenyl group, bromophenyl group, chloro-methyl-phenyl group, dichlorophenyl group, methoxyphenyl group, cyanophenyl group) , acetamidophenyl group, fluorophenyl group, butoxyphenyl group, etc.).

In addition, 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 acid anhydride and aromatic dicarboxylic acid anhydride. Can be mentioned.

Examples of aliphatic dicarboxylic anhydrides include succinic anhydride ring, glucuconic acid anhydride ring, maleic anhydride ring, cyclopentane-1,2-dicarboxylic anhydride ring, and cyclohexane-1,2-dicarboxylic acid anhydride ring. Examples include anhydride ring, cyclohexene-1,2-dicarboxylic anhydride ring, 2,3-bicyclo(2,2,2)octanedicarboxylic anhydride ring, etc., and these rings have 1 go, for example, a chlorine atom, Halogen atoms such as bromine atoms, methyl groups, ethyl groups, butyl groups,
Alkyl groups such as hexyl groups may be substituted.

Examples of aromatic dicarboxylic anhydrides include phthalic anhydride rings, naphthalenedicarboxylic anhydride rings, pyridine-dicarboxylic anhydride rings, thiophene-dicarboxylic anhydride rings, etc. , 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,
It may be substituted with a cyano group, a nitro group, an alkoxylcarbonyl group (as an alkoxy group, for example, a methoxy group, an ethoxy group, etc.), or the like.

The copolymerization component corresponding to the repeating unit (ii) containing an acidic group of the present invention can be copolymerized with a methacrylate monomer corresponding to the repeating unit represented by formula (1) or formula (n), for example. Any vinyl compound containing the acidic group may be used.
It is described in 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 methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid half amides, crotonic acid, 2-alkenylcarboxylic acids (e.g. 2-pen-tenoic 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 or allyl group of dicarboxylic acids Examples include half ester derivatives of , ester derivatives of these carboxylic acids or sulfonic acids, and compounds containing the acidic group in the substituent of amide derivatives.

"The acidic group-containing repeating unit (ii) J will be exemplified.

b+ =ll, C11i (b+' and below) OO
H ii-3) b.

Integer from n-1 to 11 ii -10) 1←CH*-CH+ H3 CONHCH2COC5O3H COO(CHz)zOcOcH=ctl-COOHCH
.

ii-17) 1←CH, -CH÷ ii-18) b.

ii-19) 0O11 C1, GOOR R=C, ~C4 alkyl group ii-21) t ii-22) b.

ii-27) ii-23) −←cut−c++← m: integer from 2 to 10 ii-24) One←cat-cH← ii-25) b.

t ii-29) ii-26) b.

t O//\O'Tsu0 iI -31) ii -32) m: an integer of 2 to 1O Rj C, an alkyl group, a benzyl group, a phenyl group, and also in the repeating unit (ii) of the present invention ``Heat and ψ
The expression "photocurable functional group" refers to a functional group that performs a curing reaction of resin by at least one of heat and light.

Specific examples of photocurable functional groups include Hideo Inui, Gentabe Nagamatsu, "Photosensitive Polymer" (Kodansha, 1977), Takahiro Tsunoda, "New Photosensitive Resin" (Printing Society Publishing Department, 1981)
Annual), G, [+, Green and B, P, 5
tark, J., Macro.

Sci, Reas, Macro Chem, C21 (
2), 187-273 (1981-82), C, G,
Rattey, rPhotopolya+1rjz
ation of Surface Coatings”
(A, Wiley InterScience Pub
.

Functional groups used in conventionally known photosensitive resins and the like are used as the photocurable resins cited in the review articles such as 1982).

Furthermore, the "thermosetting functional group" in the present invention refers to a functional group other than the above-mentioned acidic group. , Yuji Harasaki [Latest Binder Technology Handbook] Chapter 11-1 (General Technology Center, published in 1985), Otsu Accompanying "Synthesis, Design and Development of New Applications of Acrylic Resins" (Chubu Management Development Center Publishing Department, published in 1985), Omori The functional groups cited in the review articles such as Eizo's "Functional Acrylic Resins" (Technosystem, 1985) can be used.

For example, -○H group, -3H group, -NH* group, -NIIR,
group (R1 represents a hydrocarbon group, for example, a group having 1 to 10 carbon atoms)
an optionally substituted alkyl group (e.g. methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, 2-chloroethyl group, 2-methoxyethyl group, 2-cyanoethyl group, etc.), carbon 4 to 8 optionally substituted cycloalkyl groups (e.g. cycloheptyl group,
cyclohexyl group, etc.), an optionally substituted aralkyl group having 7 to 12 carbon atoms (e.g. benzyl group, phenethyl group,
3-phenylpropyl group, chlorobenzyl group, methylbenzyl group, methoxybenzyl group, etc.), optionally substituted aryl groups (e.g. phenyl group, tolyl group, silyl group,
chlorophenyl group, bromophenyl group, methoxyphenyl group, naphthyl group, etc.], CONHCHgORx (Rt is a hydrogen atom or a carbon number of 1
-8 alkyl groups (e.g. methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, etc.) (al
+ at can each represent a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, etc.), or an alkyl group having 1 to 4 carbon atoms (for example, a methyl group, an ethyl group, etc.). Moreover, specifically as the polymerizable double bond group,
-CIIt・CI(-1C11!・CH-CHffi
-CToIICH-NHCO-1CH*lIC)l-C
Hg-1NHCO-CHg-CH-5o Goose-1CH! =
CH-C0-1CIIt=CH-0-C)lx=CH-
S-, etc. can be mentioned.

In the present invention, as a method for making the binder resin contain at least one type of functional group selected from the group of the curable functional groups, a method of introducing the functional group into the polymer by a polymer reaction, or a method of incorporating one type of the functional group or one or more monomers containing one or more monomers, a monomer corresponding to the repeating unit of general formula (1) or (n), and a monomer corresponding to the "acidic group-containing copolymer component" It can be obtained by a method such as copolymerization reaction with a polymer.

For polymer reactions, conventional methods for low molecule synthesis reactions can be used as they are.
V), (published by Maruzen Co., Ltd.), "Reactive Polymers" by Takao Iwakura and Keisuke Kurita, etc., and are described in detail in the known literature cited as a review.

On the other hand, examples of monomers containing the "functional group that performs photo and/or thermosetting reactions" include - copolymerization with monomers corresponding to repeating units of general formula (1) or (II) Examples include vinyl compounds containing such functional groups. Specifically, the above-mentioned "acidic group-containing compound"
Examples include compounds similar to those containing the functional group in the substituent.

The repeating unit (iii) containing a "thermal/photocurable functional group" will be exemplified.

bs: -H, -CHa (bz: the same below) C00
CHzCH+=CHz if -5) if -8) ba R knee Cl-C1hl-CHz (JI=C1hb4:H
, cHs (ba: the same below) tii -9) iii -6) -CO-R iii -7) iii -10) COOCToCHCHzooC-R Integer of 1-11 iii -11) iii-15) n ; of l to 4 Integer Z knee 5--Q- ui -16) 1,000 CH, -CH→- 1ii -12) in -17) CONHGHZOR :01-C4 alkyl group Coo(CHz) rl-Z Z : -0)1. -NH2 n : an integer of 2 to 11 m -19) -CH-Cl
A monomer corresponding to the repeating unit of t), a monomer containing the acidic group, and any monomer containing the photo- and/or thermosetting functional group, as well as other monomers other than these. may be contained as a copolymerization component.

For example, α-olefins, vinyl alkanoates or allyl esters, acrylonitrile, methacrylonitrile, vinyl ethers, acrylic esters, methacrylic esters, acrylamides, methacrylamides, styrenes, heterocyclic vinyls (e.g. vinylpyrrolidone, vinylpyridine, vinylimidazole, vinylthiophene, vinylimidacillin, vinylpyrazole, vinyldioxane, vinylkyrin, vinylthiazole, vinyloxazine, etc.).

In the present invention, in order to promote the crosslinking reaction in the photosensitive layer, especially when the functional group contains photo- and/or thermosetting functional groups, a reaction accelerator may be added as necessary. For example, in the case of a reaction mode that forms a chemical bond between organic acids (acetic acid, propionic acid, butyric acid, benzenesulfonic acid,
crosslinking agents such as p-toluenesulfonic acid, etc.

As a crosslinking agent, specifically, Shinzo Yamashita and Tosuke Kaneko ed.
Compounds described in "Crosslinking Agent Handbook" published by Taiseisha (1981) etc. can be used. For example, commonly used crosslinking agents such as organic silane, polyurethane, polyisocyanate, epoxy resin, melamine resin, etc. A curing agent or the like can be used.

In the case of a polymerizable reaction mode, a polymerization initiator (peroxide, azobis-based compound, etc., preferably an azobis-based polymerization initiator), a monomer containing a polyfunctional polymerizable group (for example, vinyl Methacrylate, allyl methacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, divinyl succinate, divinyl adipate, diallyl succinate,
2-methylvinyl methacrylate, divinylbenzene, etc.).

Furthermore, in the case of a resin containing a photocrosslinkable functional group, a sensitizer, a photopolymer monomer, etc. may be added, specifically compounds cited in the above-mentioned review on photosensitive resins. etc. can be used.

Further, in the present invention, when using a binder resin containing a thermosetting functional group, a thermosetting treatment is performed. This heat curing treatment can be performed by tightening the drying conditions during conventional photoreceptor production.

For example, when using a resin containing a photocrosslinkable functional group, which can be subjected to sensitization treatment at 60'C to 120C for 5 to 120 minutes, after coating the photosensitive layer-forming material, electron beam, X-ray, Crosslinking is carried out by irradiation with ultraviolet rays or plasma light, and this can be done not only during drying, but also before or after drying, and the reaction is further accelerated by heating under the above drying conditions. When containing a heat and/or photocurable functional group,
When the above-mentioned reaction accelerator is used in combination, it becomes possible to perform the treatment under milder conditions.

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

Preferable examples include zinc oxide and titanium oxide. The total amount of binder resin used for the inorganic photoconductive material is 10 to 100 parts by weight, preferably 15 to 50 parts by weight, based on 100 parts by weight of the photoconductor.

In the present invention, various dyes can be used in combination as spectral sensitizers, if necessary. For example, Harumi Miyamoto: Hidehiko Takei; Imaging 1973 (No. 8) 12th True, C
, J. Young et al., RCA Review 1546
9 (1954), Wataru Kiyota, Journal of the Institute of Electrical Communication, No. 2, 97 (1980), Yuji Harasaki et al., Industrial Chemistry Journal Fall, ■ and 188 (1963), Tadaaki Tani, Photographic Society of Japan Carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthine dyes, phthalein dyes, cited in reviews such as Shijin, 208 (1972),
Examples include polymethine dyes (for example, oxonol dyes, merocyanine dyes, cyanine dyes, logocyanine dyes, styryl dyes, etc.), phthalocyanine dyes (which may contain metal), and the like.

More specifically, examples using mainly carbonium dyes, triphenylmethane dyes, xanthine dyes, and phthalein dyes include Japanese Patent Publication No. 51-452, Japanese Patent Application Laid-open No. 50-90334, and Japanese Patent Application Laid-open No. 50-90334. No. 50-114227,
JP 53-39130, JP 53-82353, U.S. Patent No. 3052540, U.S. Patent No. 40544
50, JP-A-57-16456, and the like.

oxonol dye, merocyanine dye, cyanine dye,
Polymethine dyes such as logcyanine dyes include F, M
, Hanner, rTha Cyanine Dy
es andRelated Compounds J
It is possible to use the pigments described in et al., and more specifically,
U.S. Patent No. 3,047,384, U.S. Patent No. 311,059
No. 1, U.S. Patent No. 3121008, U.S. Patent No. 312
No. 5447, U.S. Patent No. 3128179, U.S. Patent No. 3132942, U.S. Patent No. 3622317, British Patent No. 1226892, British Patent No. 1309274, British Patent No. 1405898, Japanese Patent Publication No. 48-7814
Examples include dyes described in Japanese Patent Publication No. 55-18892.

Furthermore, as a polymethine dye that spectrally sensitizes the near-infrared to infrared light region with a long wavelength of 700n+s or more, JP-A-47-84
No. 0, JP-A No. 47-44180, JP-A No. 51-410
No. 61, JP-A-49-5034, JP-A-49-451
No. 22, JP-A-57-46245, JP-A-56-35
No. 141, JP-A-57-157254, JP-A-61-
No. 26044, JP-A No. 61-27551, U.S. Patent No. 3619154, U.S. Patent No. 4175956゛,r
Re5-earch Disclosure” 19B
2, 216, pp. 117-118.

The photoreceptor of the present invention is also excellent in that even when various sensitizing dyes are used in combination, its performance does not change easily due to the sensitizing dye.

Furthermore, if necessary, various conventionally known additives for electrophotographic photosensitive layers such as chemical sensitizers can be used in combination. For example, the above-mentioned review: Imaging 1973 (No.
, 8) Electron-accepting compounds (e.g., halogens, benzoquinones, cranyl, acid anhydrides, organic carboxylic acids, etc.) cited in the 12th True Review, Hiroshi Komon et al., "Recent Development and Practical Use of Photoconductive Materials and Photoreceptors" Examples include polyarylalkane compounds, hindered phenol compounds, p-phenylenediamine compounds, and the like cited in the review of Nippon Kagaku Information Publishing Department (1986), Chapters 4 to 6 of "Nihon Kagaku Information Publishing Department" (1986).

The amount of these various additives added is not particularly limited, but is usually 0.0001 to 2.0 parts by weight per 100 parts by weight of the photoconductor.
Parts by weight.

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

In addition, when a photoconductive layer is used as a charge generation layer of a laminated type photoreceptor consisting of a charge generation layer and a charge transport layer, the thickness of the charge generation layer is 0.01 to 1μ, particularly 0.05 to 0.5μ. suitable.

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 μm, particularly 10 to 3 μm.
0μ is suitable.

Typical resins used to form the insulating layer or charge transport layer include polystyrene resin, polyester resin, cellulose resin, polyether resin, vinyl chloride resin, vinyl acetate resin, hydrochloric acid and copolymer resin, Thermoplastic resins and curable resins such as polyacrylic resins, polyolefin resins, urethane resins, polyester resins, epoxy resins, melamine resins, and silicone resins are used as appropriate.

The photoconductive layer according to the invention can be provided on a conventionally known support. Generally speaking, the support of the electrophotographic photosensitive layer is preferably electrically conductive, and the electrically conductive support can be made by impregnating a low-resistance substance with a base material such as metal, paper, or plastic sheet, just as in the conventional case. those that have been subjected to conductive treatment, such as those that have been coated with at least one layer for the purpose of imparting conductivity to the back surface of the substrate (the surface opposite to the surface on which the photosensitive layer is provided) and also to prevent curling, and those that have been coated with at least one layer for the purpose of preventing curling, etc. Those with a water-resistant adhesive layer on the surface of the body, those with at least one pre-coated layer provided on the surface layer of the support as required, and those with a conductive plastic base coated with AI or the like and laminated with paper. can be used.

Specifically, examples of conductive substrates or conductive materials include:
Yukio Sakamoto, Electrophotography, 14, (No. 1), No. 2-11
Page (1975), Hiroyuki Moriga, "Introductory Special Paper Chemistry" Kobunshi Publishing (1975), M, F, Hoover+ J,
MacroIlol, Sci.

Chea, ^-4(6), pp. 1327-1417 (
1970) etc. are used.

(Example) Examples of the present invention are illustrated below, but the content of the present invention is not limited thereto.

Synthesis Example 1 A mixed solution of 95 g of 2.6-dichlorophenyl methacrylate, 5 g of acrylic acid, and 200 g of toluene was heated to a temperature of 90"C under a nitrogen stream, and then 2,2"-azobis(
6 g of isobutyronitrile) was added and reacted for 8 hours.

The weight average molecular weight of the obtained copolymer (1) was 8.500.
．． The glass transition point was 60°C.

Synthesis Example 2 A mixed solution of 95 g of ethyl methacrylate, 5 g of acrylic acid, and 200 g of toluene was heated to a temperature of 90'C under a nitrogen stream, and then 6.0 g of azobisisobutyronitrile was added and reacted for 8 hours. The weight average molecular weight of the obtained copolymer (^) was 8,500, and the glass transition point was 42°C.

Synthesis Example 3 After heating a mixed solution of 98 g of ethyl methacrylate, 2 g of acrylic acid, and 200 g of toluene to a temperature of 75°C under a nitrogen stream, 1.5 g of 2.2'-azobis(isobutyronitrile) was added, and 8 Allowed time to react. The weight average molecular weight of the obtained copolymer (B) was 32,000, and the glass transition point was 45°C.

Example 1 40 g (as solid content) of copolymer (1) produced in Synthesis Example 1, 200 g of zinc oxide, 0.02 g of heptamethine cyanine dye represented by the following structural formula, 0 phthalic anhydride
．． A mixture of 10 g of toluene and 300 g of toluene was dispersed in a ball mill for 2 hours to prepare a photosensitive layer-forming product, and this was coated on electrically conductive treated paper with a wire bar so that the dry adhesion amount was 20 g/rrf. Dry for 30 seconds at 0°C.
Next, an electrophotographic light-sensitive material was prepared by allowing the mixture to stand in a dark place at 20° C. and 165% RH for 24 hours.

(Cyanine dye) Comparative Example A Same as Example 1 except that 40 g (as solid content) of the copolymer (^) produced in Synthesis Example 2 was used instead of the copolymer (1) used in Example 1. A comparative electrophotographic photoreceptor A was manufactured.

Comparative Example B 40 g of copolymer (B) produced in Synthesis Example 3 instead of copolymer (1) used in Example 1 (as solid content)
Comparative electrophotographic photoreceptor B was manufactured in the same manner as in Example 1 except for using the following.

The film properties (surface smoothness), electrostatic properties, imaging performance, and imaging performance of these photosensitive materials under environmental conditions of 30° C. and 280% RH were investigated. Furthermore, when these photosensitive materials are used as original plates for offset masters, the photoconductive desensitization property (represented by the contact angle with water of the photoconductive layer after desensitization treatment) and printability (background smudge, The printing durability, etc.) were investigated.

Imaging performance and printability were determined by exposing and developing the image using a fully automatic plate making ELP404ν (manufactured by Fuji Photo Film ■) using the developer ELP-T, and using an etching processor using the desensitizing liquid ELP-E. The test was carried out using a lithographic printing plate obtained by etching (the printing machine used was Hamada Star 8005X model manufactured by Hamada Star ■).

The above results are summarized in Table-1.

The implementation conditions for the evaluation items shown in Table 1 are as follows.

Note 1) Smoothness of photoconductive layer: The obtained photosensitive material was tested using a Beck smoothness tester (Kumagai Riko ■
The smoothness (
see/cc) was measured.

Note 2) Electrostatic properties: In a dark room at a temperature of 20°C and 65% RH, each photosensitive material was subjected to corona discharge at -6 kV for 20 seconds using a paper analyzer (Paper Analyzer 5P-428 model manufactured by Kawaguchi Electric). After that, leave it for 10 seconds, and at this time the surface potential V,
. The potential V was measured after 0 and then left to stand still for 60 seconds in the dark. is measured, and the potential retention after decaying for 60 seconds, that is, the dark decay retention rate (DRR(χ)), is expressed as (
V,,o/VIo) 830 nm) light,
The time required for the surface potential (V+.) to attenuate to 1/10 is determined, and the exposure amount E,/1° (erg/cd) is calculated from this time.

The environmental conditions at the time of measurement were 20°C, 965%RH (1) and 3.
The test was carried out at 0° C. and 80% RH (n).

Note 3) tI image property: After each photosensitive material was left for one day and night under the following environmental conditions, each photosensitive material was charged at -6 KV and 2.8+aW was used as a light source.
Output gallium-aluminum-arsenic semiconductor laser (
6 on the surface of the photosensitive material using an oscillation wavelength of 830rv).
After exposure under an irradiation dose of 4erg/cd at a pitch of 25μ and a scanning speed of 30rg/see, as a liquid developer! ! Using LP-T (manufactured by Fuji Photo Film), the resulting copy image (fogging, image quality) was visually evaluated by developing and fixing. The environmental conditions during imaging were: 20°C, 65% RH (1), 30°C, 80% RH (I
It was carried out in t).

Note 4) Contact angle with water: Each photosensitive material is treated with a desensitizing treatment liquid [! Using LP-E (manufactured by Fuji Photo Film ■), the surface of the photoconductive layer was desensitized by passing it through an etching processor once, and then a water droplet of 2 pl of distilled water was placed on it, and the contact angle with the water formed was measured. is measured with a goniometer.

Note 5) Printing durability After making the plate in the same manner as the image retention in Note 3) above, it was desensitized under the same conditions as Note 4) above, and this was used as an offset master on an offset printing machine (manufactured by Sakurai Seisakusho ■). This indicates the number of sheets that can be printed using high-quality paper (Oliver 52 model) as the printing paper without causing background stains in the non-image areas of the printed matter or problems with the image quality of the image areas (the higher the number of sheets printed, the better the printing durability. (represents something).

As shown in Table 1, in the photosensitive material of the present invention, the photoconductive layer had good smoothness and electrostatic properties, and the actual copied images had no ground blur and the quality of the copied images was clear.

This means that the photoconductor and the binder resin are sufficiently adsorbed, and
This is presumed to be due to coating 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 15 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.

Comparative Example A using a copolymer containing ethyl methacrylate as a copolymerization component, which contains the same acid component as the resin of the present invention and has a low molecular weight, has electrostatic properties and its plate at room temperature. The printing properties used showed good results, almost the same as those of the present invention, but the electrostatic properties deteriorated under high temperature and high humidity, and Vo, [1, R, R, and El/ 16
The quality of both images deteriorated, and the actual copied images were not of sufficient quality.

In addition, in Comparative Example B, which is a copolymer (ethyl methacrylate/acrylic acid) similar to Comparative Example A and has a large weight average molecular weight, the smoothness of the photoconductive layer is significantly poor, and the electrostatic properties and In particular, the DRR deteriorated. Even when used as an offset master, the contact angle with water in the non-image area after desensitization treatment was as large as 25 to 30 degrees, and there was large variation, and even in actual printing. Scratching occurred from the beginning of printing.This is presumed to be due to the increase in the molecular weight of the binder resin, which causes adsorption to the photoconductor particles and aggregation between the particles, resulting in an adverse effect.

From the above, an electrophotographic photoreceptor that satisfies electrostatic properties and printability can be obtained only when the resin of the present invention is used.

Examples 2 to 19 As resins, copolymers shown in Table 2 were manufactured under the same manufacturing conditions as in Synthesis Example 1.

The weight average molecular weight of each of the resulting resins (2) to 09) was 7,000 to 8.000.

Table 2 Each photoreceptor was manufactured in the same manner as in Example 1, except that 40 g (as solid content) of each resin shown in Table 2 was used instead of copolymer (1) used in Example 1. Then, each characteristic was measured in the same manner as in Example 1. The surface smoothness of the photoconductive layer of each photoreceptor was all 80 (see/cc) or higher. The results regarding electrostatic properties and imaging properties are shown in Table 3.

All of the photosensitive materials of the present invention have excellent chargeability, dark charge retention, and photosensitivity, and the actual reproduced images are also produced at high temperatures (30°C, 80°C).
Even under severe conditions (%RH), it provided clear images with no occurrence of ground blur or fine line skipping.

Table 3 Examples 20 to 36 The copolymers shown in Table 4 (the weight average molecular weight of each resin is 6,500 to 9,500) were used as resins in place of resin (1) used in Example 1. , and other operations were performed in the same manner as in Example 1 to produce each photosensitive material.

Each characteristic was measured in the same manner as in Example 1. The surface smoothness of the photoconductive layer of each photoreceptor was all 80 (sec/cc) or more. The results regarding electrostatic properties are also shown in Table 4.

All of the photosensitive materials of the present invention have excellent chargeability, dark charge retention, and photosensitivity, and the actual reproduced images are produced at high temperatures (30°C, 18°C).
Even under the harsh conditions of 0% RH), clear images were produced without any occurrence of ground blur or fine line skipping.

Example 37 A copolymer having the following chemical structure was used as the resin of the present invention.

Resin (37) 40 g of the resin, 200 g of zinc oxide, 0.
05 g1 phthalic anhydride 0.01 g and toluene 300
The mixture of g was dispersed in a ball mill for 2 hours. Next, 10 g of allyl methacrylate and 2,2゛-
0.5 g of azobisisobutyronitrile was added and dispersed in a ball mill for 10 minutes to prepare a photosensitive layer formed product.

This was applied to electrically conductive treated paper with a wire bar so that the dry adhesion amount was 25 g/po, and dried at 80°C for 1 hour and then at 100°C for 30 minutes. Then in the dark at 20°C.
An electrophotographic photoreceptor was produced by leaving it for 24 hours under conditions of 165% RH.

The electrostatic properties of the obtained photosensitive material were measured in the same manner as in Example 1. However, the light attenuation exposure amount ([!l/I.) is
After the surface of the photoconductive layer is charged to -400V by corona discharge, the photoconductive surface is irradiated with visible light at an illuminance of 2.0 lux, and the time required for the surface potential (V+) to attenuate to 1/10 is determined. From this, the exposure amount E+/+o (lux/second) was calculated. The result is ■. Knee 620VD, R
, R-92%+Lz+os6.31ux, sec.

Furthermore, this was made into ELP-T using a fully automatic plate making machine ELP404V.
) The master plate for offset printing obtained had a density of 1.0 or more and a clear image quality. Furthermore, when etching was performed and printed on a printing press, the printed matter after printing 7,000 sheets had no capri in the non-image area and the image was clear. Also (30°C180%R
The electrostatic properties, one-image performance, and printability were similarly measured under the environmental conditions of H), but no differences were observed from those at room temperature.

Examples 38 to 43 In Example 37, each electrophotographic photosensitive material was prepared in the same manner as in Example 37, except that the copolymer shown in Table 5 below was used instead of the resin (37) of the present invention. The material was prepared.

Table 5 When this was plate-made using the same apparatus as in Example 37, the density of the obtained offset printing master plate was 1.0 or more and the image quality was clear. After further etching and printing on a printing press, the printed matter after printing 7,000 sheets had clear image quality with no fogging.

Examples 44 and 45 Each photosensitive material was produced in the same manner as in Example 37, except that the copolymer shown in Table 6 below was used instead of the resin (37) of the present invention. However, the drying conditions after coating were 110° C. for 12 hours.

The front plate was made into a plate using the same apparatus as in Example 37, and then etched and printed using a printing press. The density of the master plate for offset printing obtained after plate making was 1.1 or more, and the image quality was clear. In addition, the image quality of the printed matter after printing 5,000 sheets was clear and free of blur.

(Effects of the Invention) According to the present invention, it is possible to obtain an electrophotographic photoreceptor which is excellent in the smoothness of the photoconductive layer, electrostatic properties, imaging properties, as well as desensitization property and background smudge, especially under high temperature and high humidity conditions. These excellent properties are maintained even under such harsh conditions.

Furthermore, the photosensitive material of the present invention has a sufficiently high printing durability of about several dozen sheets. When the binder resin further contains a copolymer component containing a heat-curable and/or photo-curable functional group, such rigidity resistance is further improved.

Furthermore, the electrophotographic photoreceptor of the present invention has excellent smoothness of the photoconductive layer even when used in combination with various sensitizing dyes.

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor having a photoconductive layer containing at least an inorganic photoconductive material and a binder resin, the binder resin has a weight average molecular weight of 1 x 10^3 to 2 x 10^4, and An electrophotographic photoreceptor characterized by containing at least one resin containing the following repeating units (i) and (ii) as a copolymerization component. (i) At least one represented by formula (I) or formula (II)
30% or more of repeating units by weight Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, X_1 and X_2 each independently represent a hydrogen atom. , a hydrocarbon group having 1 to 10 carbon atoms, a chlorine atom, a bromine atom, -COY_1 or -COOY_2 (Y_1 and Y
_2 each represents a hydrocarbon group having 1 to 10 carbon atoms. However, both X_1 and X_2 do not represent hydrogen atoms. W_1 and W_2 each represent a direct bond or a connecting group having 1 to 4 connected atoms that connects -COO- and the benzene ring. ) (ii) -PO_3H_2 group, -SO_3H group, -CO
OH group, ▲ Numerical formula, chemical formula, table, etc. ▼ group {R is a hydrocarbon group with 1 to 10 carbon atoms or -OR'(R' is a hydrocarbon group with 1 to 10 carbon atoms)
}, at least one repeating unit containing at least one substituent of an acidic group of a -SH group and a phenolic OH group, and a cyclic acid anhydride-containing group, 0.5 to 1
5% by weight (2) The resin contained in the binder resin is (i) and (i)
Claim (1) The resin further contains the following repeating unit (ii) as a copolymerization component in addition to the repeating unit i).
The electrophotographic photoreceptor described above. (iii) 1 to 20% by weight of at least one repeating unit containing a thermally and/or photocurable functional group;