JPH0820779B2 - Electrophotographic lithographic printing plate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic lithographic printing plate precursor prepared by an electrophotographic method, and more particularly to a binder for forming a photoconductive layer of the lithographic printing plate precursor. Regarding improvement of resin.

(Prior Art) At present, various types of offset master plates for direct plate making have been proposed and put into practical use. Among them, the main component is a photoconductive particle such as zinc oxide and a binder resin on a conductive support. In the photoconductor provided with the photoconductive layer described above, a highly lipophilic toner image is formed on the photoconductor surface through a normal electrophotographic process, and then the surface is treated with a desensitizing solution called an etchant. A technique for obtaining an offset original plate by selectively making a non-image portion hydrophilic is widely used.

In order to obtain a good printed matter, first, on the offset original plate,
The original image is faithfully copied, the surface of the photoconductor is easily compatible with the desensitizing solution, and the non-image area is sufficiently hydrophilic, and at the same time has water resistance. Should not be removed, and it should be well compatible with fountain solution, and the hydrophilicity of the non-image area should be sufficiently maintained so that stains do not occur even when the number of printed sheets increases.

It is already known that the ratio of zinc oxide to the binder resin in the photoconductive layer affects these performances. For example, if the ratio of the binder resin to the zinc oxide particles of the photoconductive layer is reduced, the desensitizing property of the photoconductive layer surface is improved and the background stain is reduced, but on the other hand, the internal cohesive force of the photoconductive layer itself is reduced. And the printing durability is reduced due to insufficient mechanical strength. On the contrary, if the ratio of the binder resin is increased, the printing durability is improved,
Soil pollution increases. Needless to say, the background stain is a phenomenon related to the quality of the desensitizing property of the surface of the photoconductive layer, but the desensitizing property of the surface of the photoconductive layer is a phenomenon of the zinc oxide and the binder resin in the photoconductive layer. It has become clear that not only the ratio but also the type of binder resin greatly affects.

Known resins have long been known, for example, silicone resin (Japanese Patent Publication Sho 34-6670), styrene-butadiene resin (Japanese Patent Publication 35-1950), alkyd resin, maleic acid resin, polyamide (Japanese Patent Publication 35-11219), vinyl acetate resin ( Japanese Patent Publication 41
-2425), vinyl acetate copolymer (Japanese Patent Publication No. 41-2426), acrylic resin (Japanese Patent Publication No. 35-11216), acrylate copolymer (eg Japanese Patent Publication No. 35-11219, Japanese Patent Publication No. 36-8510, Japanese Patent Publication No. 4).
1-13946 etc.) are known. However, in electrophotographic photosensitive materials using these resins, 1) the photoconductive layer has a low charging property, 2) the quality of the image portion of the copied image (particularly halftone dot reproducibility / resolution) is poor, and 3) exposure. Low sensitivity 4) Desensitization is not performed even when desensitized for use as an offset master. Therefore, background stain occurs on printed matter when offset printing is performed. 5) Photosensitive layer film strength is insufficient. If the offset printing is performed, the photosensitive layer may be detached, and the number of printed sheets cannot be increased. 6) The image quality is easily affected by the environment (for example, high temperature and high humidity) at the time of creating a copy image. It was

In particular, as the offset original plate, as described above, the occurrence of scumming due to insufficient desensitizing property is a big problem, and in order to improve this, various development of zinc oxide binder resin for improving desensitizing property has been studied. Is coming. For example, Japanese Examination Shokoku 50
-31011, Mw1.8-10 × 10 ⁴ obtained by copolymerizing (meth) acrylate-based monomer with other monomer in the presence of fumaric acid.
In which a resin having a Tg of 10 to 80 ° C. and a copolymer composed of a (meth) acrylate-based monomer and a monomer other than fumaric acid are used in combination. In JP-A-53-54027, at least a carboxylic acid group is formed from an ester bond. A method using a terpolymer containing a (meth) acrylic acid ester having a substituent having 7 atoms apart, JP-A-54-20735 and JP-A-57-202544 discloses acrylic acid and hydroxyethyl (meth). ) Using quaternary or quaternary copolymers containing acrylates
In 58-68046, one using a terpolymer containing a (meth) acrylic acid ester having an alkyl group having 6 to 12 carbon atoms as a substituent and a vinyl monomer containing a carboxylic acid is a desensitizing agent for the photoconductive layer. It is described that it is effective in improving sex. However, even with these resins that are said to be effective in improving the desensitizing property, when actually evaluated, the background stain and the printing durability were insufficient.

Further, as a binder resin, a resin containing a functional group capable of generating a hydrophilic group by decomposition has been studied, for example, a resin containing a functional group capable of generating a hydroxyl group by decomposition (Japanese Patent Laid-Open No. 62- 195684, JP-A-62-210475
No. JP-A-62-210476) or those containing a functional group capable of generating a carboxyl group by decomposition (JP-A-62-21269)
Etc. are disclosed.

These resins are hydrolyzed or hydrogenolyzed by a desensitizing solution or a fountain solution used for printing to produce a hydrophilic group, and when these are used as a binder resin of a lithographic printing plate precursor, they have a hydrophilic property. Various problems (such as deterioration of smoothness, deterioration of electrophotographic characteristics, etc.) which are considered to be caused by strong interaction between the hydrophilic group and the surface of the photoconductive zinc oxide particles when a resin containing the group itself is used. ) Can be avoided, and the hydrophilicity of the non-image area to be hydrophilized by the desensitizing liquid is further enhanced by the hydrophilic group generated by decomposition in the resin. It is described that the hydrophilicity of the area becomes clear, prevents printing ink from adhering to the non-image area during printing, and as a result, it is possible to print a large number of prints of clear image quality without background smear. .

(Problems to be Solved by the Invention) However, even if these resins are used, background fouling and printing durability are still unsatisfactory, and when a resin containing a hydrophilic group-forming functional group as described above is used. However, when the content is increased in order to further improve the hydrophilicity in the non-image area, the hydrophilic group generated by the decomposition increases the hydrophilicity and becomes water-soluble, so that the sustainability is particularly high. It turned out that there was a problem in sex.

Therefore, the effect by the hydrophilicity of the non-image portion is further improved,
The emergence of a technology that further improves sustainability is desired.

More specifically, even if the content of the resin containing a hydrophilic group-forming functional group as described above in the entire binder resin is reduced, the effect of improving hydrophilicity can be maintained unchanged or is improved, or The advent of a technique capable of printing a large number of printed matter with clear image quality without background stains is desired even when printing conditions such as a large-sized printing machine or fluctuations in printing pressure become severe.

(Means for Solving Problems) The above problems are caused by applying a liquid containing at least photoconductive zinc oxide, the following resin (A), the following resin (B) and toluene onto a conductive support and applying light. It has been found that the problem can be solved by a lithographic printing plate precursor using an electrophotographic photosensitive member provided with a conductive layer.

(I) Resin (A): a copolymerization component containing at least one functional group capable of generating at least one carboxyl group by decomposition and a copolymerization component containing at least one functional group capable of undergoing a crosslinking reaction with the resin [B]. (Ii) Resin (B): a methacrylate copolymer containing at least one component containing at least one functional group capable of undergoing a curing reaction with heat and / or light.

The present invention relates to a resin containing at least one functional group capable of decomposing to produce at least one carboxyl group in at least a part of a binder resin of a photoconductive layer of a lithographic printing plate, and a heat and / or photocurable resin. It is characterized by using and. As a result, the lithographic printing plate precursor according to the present invention reproduces a copy image faithful to the original image, and since the non-image area has good hydrophilicity, scumming does not occur, and the smoothness and electrostatic properties of the photoconductive layer are reduced. It has the advantages of good characteristics and excellent printing durability.

Further, the lithographic printing plate precursor of the invention is characterized by being unaffected by the environment at the time of plate making processing and being excellent in preservability before processing.

Hereinafter, a functional group used in the present invention, which decomposes to form at least one carboxyl group (hereinafter simply referred to as
(Also referred to as a carboxyl group-forming functional group) will be described in detail.

The carboxyl group-forming functional group of the present invention generates a carboxyl group by decomposition, but the number of carboxyl groups generated from one functional group may be one or two or more.

According to one preferred embodiment of the present invention, the carboxyl group-forming functional group-containing resin has the general formula (I) [—COO-L ₁ ]
Is a resin containing at least one functional group represented by.

In the general formula (I) [-COO-L ₁ ], L ₁ is -N = CH-Q ₁ , -NH-OH, Represents

However, R ₁ and R _{2, which} may be the same or different, each represents a hydrogen atom or an aliphatic group, X represents an aromatic group, Z is a hydrogen atom, a halogen atom, a trihalomethyl group or an alkyl group. _{, -CN, -NO 2, -SO 2} R 1 '( where, R _1'
Represents a hydrocarbon group), —COOR ₂ ′ (wherein R ₂ ′ represents a hydrocarbon group), or —O—R ₃ ′ (wherein R ₃ ′ represents a hydrocarbon group), n, m represents 0, 1, or 2.

R ₃ , R ₄ and R _{5, which} may be the same or different, each represents a hydrocarbon group or —O—R ₄ ′ (provided that R ₄ ′ represents a hydrocarbon group), M represents Si, Represents Sn or Ti.

Q ₁ and Q ₂ each represent a hydrocarbon group.

Y ₁ represents an oxygen atom or a sulfur atom, R ₆ , R ₇ and R ₈ may be the same or different and each represents a hydrogen atom or an aliphatic group, and p represents an integer of 3 or 4. Y ₂ represents an organic residue forming a cyclic imide group.

The functional group of the general formula [-COO-L ₁ ] generates a carboxyl group by decomposition, and will be described in more detail below.

L ₁ is In the case of representing, R ₁ and R ₂ may be the same or different from each other, preferably a hydrogen atom, or an optionally substituted linear or branched alkyl group having 1 to 12 carbon atoms (for example, a methyl group). , Ethyl group,
Propyl group, chloromethyl group, dichloromethyl group, trichloromethyl group, trifluoromethyl group, butyl group, hexyl group, octyl group, decyl group, hydroxyethyl group, 3-chloropropyl group, etc., and X is preferably Represents a phenyl group or naphthyl group which may be substituted (eg, phenyl group, methylphenyl group, chlorophenyl group, dimethylphenyl group, chloromethylphenyl group, naphthyl group, etc.), and Z is preferably a hydrogen atom or a halogen atom (eg, chlorine Atom, fluorine atom, etc.), trihalomethyl group (eg, trichloromethyl group, trifluoromethyl group, etc.), and optionally substituted linear or branched alkyl group having 1 to 12 carbon atoms (eg, methyl group, chloro group) Methyl group, dichloromethyl group, ethyl group, propyl group, butyl group, hexyl group, tetrafluor Roechiru group, octyl group, cyanoethyl group, chloroethyl group, _{etc.), - CN, -NO 2,} -SO 2 R
₁ '[R _1' represents an aliphatic group (e.g. an optionally substituted alkyl group having 1 to 12 carbon atoms: for example, methyl group, ethyl group,
Propyl group, butyl group, chloroethyl group, pentyl group,
Aralkyl group having 7 to 12 carbon atoms and optionally substituted such as octyl group: specifically, benzyl group, phenethyl group, chlorobenzyl group, methoxybenzyl group, chlorophenethyl group, methylphenethyl group, etc.) or aromatic group ( For example, a phenyl group or naphthyl group which may contain a substituent: specifically, a phenyl group, a chlorophenyl group, a dichlorophenyl group, a methylphenyl group, a methoxyphenyl group, an acetylphenyl group, an acetamidophenyl group, a methoxycarbonylphenyl group, Naphthyl group, etc.], -CO
OR ₂ ′ (R ₂ ′ has the same meaning as R ₁ ′ above) or —O—R ₃ ′
(R ₃ ′ has the same meaning as R ₁ ′ above). n and m represent 0, 1 or 2.

Is L ₁ described above When the case of is described more specifically, the following examples of substituents can be given.

For example, β, β, β-trichloroethyl group, β, β,
β- trifluoroethyl group, a hexafluoro -i- _{propyl, -CH 2 CF 2 CF 2 n} 'H group (n' represents 1 to 5), 2-cyanoethyl, 2-nitroethyl group, 2-methane Sulfonylethyl group, 2-ethanesulfonylethyl group, 2
-Butanesulfonylethyl group, benzenesulfonylethyl group, 4-nitrobenzenesulfonylethyl group, 4-cyanobenzenesulfonylethyl group, 4-methylbenzenesulfonylethyl group, benzyl group which may contain a substituent (for example, benzyl group, methoxy group) A benzyl group, a trimethylbenzyl group, a pentamethylbenzyl group, a nitrobenzyl group, etc.), a phenacyl group which may contain a substituent (for example, phenacyl group, bromophenacyl group, etc.), and a phenyl group which may contain a substituent (for example, Phenyl, nitrophenyl, cyanophenyl, methanesulfonylphenyl, trifluoromethylphenyl, dinitrophenyl, etc.).

Also L ₁ In the formula, R ₃ , R ₄ , and R ₅ may be the same or different from each other, and are preferably an aliphatic group having 1 to 18 carbon atoms which may be substituted [the aliphatic group is an alkyl group, an alkenyl group, Represents an aralkyl group or an alicyclic group, and examples of the substituent include a halogen atom, a —CN group, a —OH group, and —O—Q ′.
(Q ′ represents an alkyl group, an aralkyl group, an alicyclic group, an aryl group), etc.], and an optionally substituted aromatic group having 6 to 18 carbon atoms (eg, a phenyl group, a tolyl group, a chlorophenyl group) , methoxyphenyl group, acetamidophenyl group, a naphthyl group, etc.), or -O-R ₄ '[R _4' is substituted alkyl group of good 1 to 12 carbon atoms, the carbon atoms which may be substituted 2-12 An alkenyl group, an optionally substituted aralkyl group having 7 to 12 carbon atoms, an optionally substituted alicyclic group having 5 to 18 carbon atoms, and an optionally substituted aryl group having 6 to 18 carbon atoms] Represents

M represents each atom of Si, Ti, or Sn, more preferably
Represents a Si atom. The L ₁ is -N = CH-Q ₁ or In the case of representing, each of Q ₁ and Q ₂ is preferably an optionally substituted aliphatic group having 1 to 18 carbon atoms (as the aliphatic group, an alkyl group, an alkenyl group, an aralkyl group, and an alicyclic group are represented. Examples of the substituent include a halogen atom, CN
And an optionally substituted aryl group having 6 to 18 carbon atoms (for example, a phenyl group, a methoxyphenyl group, a tolyl group, a chlorophenyl group, and a naphthyl group).

L ₁ is In the formula, Y ₁ represents an oxygen atom or a sulfur atom. R ₆ , R ₇ and R ₈ may be the same or different from each other, and are preferably a hydrogen atom, and may have 1 to 1 carbon atoms which may be substituted.
18 linear or branched alkyl groups (eg, methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, octadecyl, chloroethyl, methoxyethyl, methoxypropyl,
Etc.), optionally substituted alicyclic group (eg cyclopentyl group, cyclohexyl group, etc.), optionally substituted aralkyl group having 7 to 12 carbon atoms (eg benzyl group, phenethyl group, chlorobenzyl group, methoxybenzyl group) Group, etc.) or an aromatic group which may be substituted (eg, phenyl group, naphthyl group, chlorophenyl group, tolyl group, methoxyphenyl group, methoxycarbonylphenyl group, dichlorophenyl group, etc.) or —O—R ₅ ′ (R ₅ 'represents a hydrocarbon group, specifically, shows the same substituents such as hydrocarbon groups of _{R 6, R 7, R 8} ) represents an.

 P represents an integer of 3 or 4.

L ₁ is In the case of representing, Y ₂ represents an organic residue forming a cyclic imide group. Preferably, the compound represented by the general formula (II) or (II)
Represents an organic residue represented by I).

General formula (II) General formula (III) In formula (II), R ₉ and R ₁₀ may be the same or different, and each is a hydrogen atom, a halogen atom (for example, a chlorine atom, a bromine atom, etc.), or an optionally substituted alkyl group having 1 to 18 carbon atoms ( For example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group,
Hexadecyl, octadecyl, 2-chloroethyl, 2,
-Methoxyethyl group, 2-cyanoethyl group, 3-chloropropyl group, 2- (methanesulfonyl) ethyl group, 2- (ethoxyoxy) ethyl group, etc., an optionally substituted aralkyl group having 7 to 12 carbon atoms (For example, benzyl group, phenethyl group, 3-phenylpropyl group, methylbenzyl group, dimethylbenzyl group, methoxybenzyl group, chlorobenzyl group, bromobenzyl group, etc.), alkenyl having 3 to 18 carbon atoms which may be substituted. Group (for example, allyl group, 3-methyl-
2-propenyl group, 2-hexenyl group, 4-propyl-2-
Pentenyl group, 12-octadecenyl group, etc.), -S-
R ₆ ′ (R ₆ ′ has the same meaning as the alkyl group, aralkyl group, and alkenyl group of R ₉ or R ₁₀ ) or an optionally substituted aryl group (for example, phenyl group, tolyl group,
Chlorophenyl group, bromophenyl group, a methoxyphenyl group, ethoxyphenyl group, an ethoxycarbonyl phenyl group, etc.), or -NHR ₇ '(R _7' represents the same content as the R ₆ '). Alternatively, R ₉ and R ₁₀ may represent a residue forming a ring (for example, a 5- or 6-membered monocyclic ring (for example, cyclopentyl ring, cyclohexyl ring), or a 5- or 6-membered bicyclo ring (for example, Bicycloheptane ring, bicycloheptene ring, bicyclooctane ring, bicyclooctene ring, etc.), and these rings may be substituted, and the substituents are the same as those described above for R ₉ and R ₁₀ . Including things. ) Q represents an integer of 2 or 3.

In the formula (III), R ₁₁ and R ₁₂ may be the same or different and have the same contents as R ₉ and R ₁₀ . Furthermore, R ₁₁ and R ₁₂ may represent an organic residue which is linked to form an aromatic ring (eg, benzene ring, naphthalene ring, etc.).

In another preferred embodiment of the present invention, the compound represented by the general formula (I
V) - it is a resin containing at least one functional group represented by [CO-L _2].

In the general formula (IV) [-CO-L ₂ ], L ₂ is Represents Here, R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ each represent a hydrogen atom or an aliphatic group.

The aliphatic group preferably has the same contents as the substituents of R ₆ , R ₇ and R ₈ . Further, R ₁₄ and R ₁₅ and R ₁₆ and R ₁₇ represent an organic residue which may combine to form a condensed ring.
Preferably, a 5- to 6-membered monocyclic ring (eg, cyclopentyl ring, cyclohexyl ring, etc.), 5- to 12-membered aromatic ring (eg, benzene ring, naphthalene ring, thiophene ring,
Pyrrole ring, pyran ring, quinoline ring, etc.).
Further, another preferred embodiment of the present invention is a resin containing at least one oxazolone ring represented by the following general formula (V).

General formula (V) In the general formula (V), R ₁₈ and R ₁₉ may be the same or different from each other, and each represents a hydrogen atom or a hydrocarbon group, or R ₁₈ and R ₁₉ may form a ring together .

Preferably, R ₁₈ and R ₁₉ may be the same or different from each other, and each may be a hydrogen atom, an optionally substituted carbon number 1 to 1.
12 linear or branched alkyl groups (for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, 2-chloroethyl group, 2-methoxyethyl group, 2-methoxycarbonylethyl group, 3-hydroxypropyl group) Etc.), an optionally substituted aralkyl group having 7 to 12 carbon atoms (eg, benzyl group, 4-chlorobenzyl group, 4-acetamidobenzyl group,
Phenethyl group, 4-methoxybenzyl group, etc.), optionally substituted alkenyl group having 2 to 12 carbon atoms (eg ethylene group, allyl group, isopropenyl group, butenyl group, hexenyl group, etc.), substituted May be a 5- to 7-membered alicyclic group (eg, cyclopentyl group, cyclohexyl group,
Chlorocyclohexyl group, etc.), optionally substituted aromatic group (eg, phenyl group, chlorophenyl group, methoxyphenyl group, acetamidophenyl group, methylphenyl group, dichlorophenyl group, nitrophenyl group, naphthyl group, butylphenyl group, dimethylphenyl group) or represents a group, etc.), ring and R ₁₈ and R ₁₉ are together (e.g., tetramethylene group, pentamethylene group, hexamethylene group, etc.) may be formed.

The resin containing at least one functional group selected from the group of functional groups represented by the general formulas (I) to (V) used in the present invention is prepared by reacting a carboxyl group contained in a polymer with a general formula [ converting the functional group -COO-L _1] or [-CO-L _2], the method according to the so-called polymer reaction, or the functional group of the general formula [-COO-L _1] or [-CO-L _2] Is obtained by a method of forming a polymer by a polymerization reaction of one or more monomers containing one or more of the above, or the monomer and another monomer copolymerizable therewith.

These methods are described, for example, in “New Experimental Chemistry Course, Volume 14, Synthesis and Reaction of Organic Compounds [V]”, 2535, edited by The Chemical Society of Japan.
Pages (published by Maruzen Co., Ltd.), Yoshio Iwakura: Keisuke Kurita, "Reactive Polymers", page 170 (published by Kodansha), etc.

The general formula [-COO-L ₁ ] or [-CO-
For the reason that the functional group of L ₂ ] can be arbitrarily adjusted or that impurities are not mixed, the general formula [-COO-L ₁ ]
Alternatively, a method of producing a monomer containing one or more functional groups of [—CO-L ₂ ] by a polymerization reaction is preferable. Specifically, a carboxylic acid containing a polymerizable double bond or an acid halide thereof is converted to a carboxyl group of the general formula [-COO-L ₁ ] or [- After conversion into a functional group of [CO-L ₂ ], polymerization can be carried out to produce the compound.

The oxazolone ring-containing resin represented by the general formula (V) may be one or more monomers containing the oxazolone ring, or the monomer and another monomer copolymerizable therewith. To a polymer by a polymerization reaction of

The oxazolone ring-containing monomer can be produced by a dehydration ring-closing reaction of N-acylloyl-α-amino acids having a polymerizable unsaturated bond. In particular,
Iwakura Yoshio. It can be produced by the method described in the literature in Keiretsu Kurita, “Reactive Polymers”, Chapter 3 (published by Kodansha).

Other monomers that can be copolymerized with these monomers include:
For example, aliphatic vinyl carboxylates such as vinyl acetate, vinyl propionate, vinyl acetate, allyl acetate, allyl propionate or allyl esters, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, etc. Such as unsaturated carboxylic acid esters or amides, styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, α-olefins, acrylonitrile, methacrylonitrile, and vinyl group-substituted heterocyclic compounds such as N-vinylpyrrolidone Is mentioned.

As described above, the copolymer component containing a functional group represented by any one of the general formulas (I) to (V) used in the method for producing a desired resin by a polymerization reaction is more specifically described, for example, by the following general formula (VI) And the like. However, it is not limited to these copolymer components.

General formula (VI) In the formula (VI), X ′ represents —O—, —CO—, —COO—, —OCO
-, −SO ₂ −, _{-CH 2 COO -, - CH 2} OCO-, Represents an aromatic group or a heterocyclic group (provided that d ₁ , d ₂ , d ₃ , d ₄
Each represents a hydrogen atom, a hydrocarbon group, or Y'-W] in formula (VI), b ₁ and b ₂ may be the same or different, and a hydrogen atom, a hydrocarbon group or formula (VI) Y'- in
W], and l represents an integer of 0 to 18].

Y'represents a carbon-carbon bond which connects the bonding group X'and the bonding group [W] and may be bonded via a hetero atom (the hetero atom represents an oxygen atom, a sulfur atom or a nitrogen atom), CH = CH, -O-, -S-, -COO -, - CONH -, - SO 2 -, - SO 2 NH -, - NHCOO-,
-NHCONH-, which has the constitution alone or in combination of binding units equal (although b _3, b _4, b ₅ are each the same meaning as the b _1, b _2.) W is formula (I) ~ Represents a functional group represented by (V).

a ₁ and a ₂ may be the same or different and each represents a hydrogen atom, a halogen atom (eg, chlorine atom, bromine atom, etc.), a cyano group, a hydrocarbon group (eg, methyl group, ethyl group, propyl group, butyl group, 1 to 12 carbon atoms which may be substituted, such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, hexyloxycarbonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, butoxycarbonylmethyl group.
Alkyl group, benzyl group, phenethyl group and other aralkyl groups, phenyl group, tolyl group, xylyl group, chlorophenyl group, and other aryl groups), or a substituent containing -W group in formula (VI) Which represents an alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aralkyl group, an alicyclic group or an aromatic group).

Further, the [-X'-Y'-] bonding residue in the formula (VI) is You may directly connect a part and -W.

W represents the symbol content represented by the general formulas (I) to (V).

Specific examples of the functional groups [W group in formula (VI)] represented by formulas (I) to (V) of the present invention are described below. However, the scope of the present invention is not limited to these.

(12) -COOCH ₂ CF ₃ (48) -COOCH ₂ OCH _{3 (50) -COOC (C 6 H} 5) 3 (51) -COOCH (C 6 H 5) 2 When the resin [A] is a copolymer, the polymer component containing a carboxyl group-forming functional group in the resin [A] of the present invention is 0.1 to 95% by weight, particularly 0.5 to 70% by weight based on the whole polymer.
%, By weight. Further, the molecular weight of the polymer of the resin [A] is preferably 10 ³ to 10 ⁶ , and particularly preferably 5 × 10 ^{3 to} 5 × 10 ⁵ .

Furthermore, the resin [A] of the present invention contains a functional group that undergoes a crosslinking reaction with the resin [B] when heated or irradiated with light.
Examples of those functional groups include functional groups similar to the functional groups showing a crosslinking reaction contained in the resin [B] described later.

Examples of the monomer corresponding to the copolymer component containing these functional groups include those copolymerized with the polymer component containing a carboxyl group-forming functional group in the resin [A] (for example, the compound of the general formula (VI)). The vinyl compound containing the crosslinkable functional group to be obtained can be mentioned.

For example, it is described in "Polymer Data Handbook [Basic Edition]", edited by Japan Society of Polymer Science, Baifukan (1986). Specifically, acrylic acid, α- and / or β-substituted acrylic acid (for example, α-acetoxy form, α-acetoxymethyl form,
α- (2-aminomethyl 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, α, β-dichloro, etc.), methacrylic acid,
Itaconic acid, itaconic acid half esters, itaconic acid half amides, crotonic acid, 2-alkenylcarboxylic acids (eg, 2-pentenoic acid, 2-methyl-2-hexenoic acid,
-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, vinyl Examples thereof include a half-ester derivative of a vinyl group or an allyl group of a sulfonic acid, a vinylphosphonic acid, a dicarboxylic acid, an ester derivative of these carboxylic acids or sulfonic acids, and a compound having the functional group in the substituent of an amide derivative.

As described above, when the resin [A] of the present invention contains the above-mentioned crosslinkable functional group, the “content of the copolymer component containing the crosslinkable functional group” is preferably in the resin [A]. It is 1 to 20% by weight, more preferably 3 to 10% by weight.

On the other hand, the resin [B] used in the present invention is a curable resin which undergoes a crosslinking reaction by heat and / or light, and preferably a resin which undergoes a crosslinking reaction with the functional groups in the above resin [A]. is there.

Preferred thermosetting resins are, specifically, Takeshi Endo "Refinement of Thermosetting Polymers" (CMC Co., Ltd., 1986), Yuji Harazaki "Latest Binder Technology Handbook", Chapter II-1 (General Technology Center, 1985), Takayuki Otsu "Synthesis and design of acrylic resin and new application development" (Chubu Business Development Center Publishing Department, 1985), Eizo Omori "Functional Acrylic Resin" (Techno System 1985), etc. As the thermosetting resin cited in the above review, a resin made of a conventionally known methacrylate copolymer is used.

Specific examples of the photocurable resin include Hideo Inui, Mototaro Nagamatsu, “Photosensitive Polymer” (Kodansha, published in 1977), Takahiro Tsunoda, “New Photosensitive Resin” (published by the Printing Society, published in 1981),
GEGreen and BP, Strark, J.Macro.Sci.Reas.Macro Ch
em., C21 (2), 187-273 (1981-82), CGRattey, "P
hotopolymirization of Surface Cootings "(A.Wiley
InterScience Pub. 1982), a conventionally known photosensitive resin or the like is used as the photocurable resin cited in the review article.

More specifically, there can be mentioned, for example, a polymer containing a functional group that undergoes a crosslinking reaction by heating or light irradiation. Examples of the crosslinkable functional group include chemical bonds between different functional groups as described below. Type (for example, the functional groups A and B in the table below react with each other in combination of at least one kind) Alternatively, a type having a self-crosslinking functional group (specifically, −
CONHCH ₂ OR ₂₀ (R ₂₀ is a hydrogen atom or a methyl group, an ethyl group,
A C1-C6 alkyl group such as a propyl group, a butyl group and a hexyl group, and a double bond group having a polymerization reactivity represented by the following formula (A)].

General formula (A) In the formula (A), X ″ represents —COO—, —OCO—, —CO—, —SO ₂
-, - CONH -, - SO 2 NH -, - O -, - S-, represents an aromatic group or a heterocyclic group, x _1, x ₂ can be the same or different, are each a hydrogen atom or a substituent Hydrocarbon groups (eg, methyl group, ethyl group, propyl group, butyl group, hexyl group, carboxymethyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, butoxycarbonylmethyl group, 2-chloroethyl group, 2-methoxy group) Ethyl group, ethoxymethyl group, benzyl group, phenethyl group, 3-phenylpropyl group, chlorobenzyl group, bromobenzyl group, methylbenzyl group, methoxybenzyl group,
Phenyl group, tolyl group, xylyl group, methoxyphenyl group, chlorophenyl group, bromophenyl group and the like), and r represents an integer of 0 or 1.

As the monomer corresponding to the copolymer component containing these functional groups, for example, a vinyl compound containing the crosslinkable functional group (specifically, the same as that described in the resin [A]) is used. Can be mentioned. Specific examples of the monomer corresponding to each of the other components that can be copolymerized with the copolymerization component containing the crosslinkable functional group are the same as those of the resin [A].

The "content of the copolymer component containing a crosslinkable functional group" in the resin [B] is particularly preferably 1 to 80% by weight.

The weight average molecular weight of the resin [B] is preferably 10 ^{3 to} 5 × 1.
0 ⁵ , more preferably 5 × 10 ^{3 to} 5 × 10 ⁵ .

In the present invention, the resin [B], which is a heat-curable and / or photo-curable resin, is used in combination to form a crosslink between the resin [A] and the resin [B] and / or a crosslink between the resins [B]. .

The ratio of the amounts of the resin [A] and the resin [B] used in the present invention is generally 5 to 80:95 to 20 (weight ratio), preferably 15 to 60:85 to 40 (weight ratio). .

In the present invention, a reaction accelerator may be added if necessary. For example, when the resin [B] is a resin containing a thermosetting functional group, an acid (for example, an organic acid such as acetic acid, propionic acid, butyric acid, etc.) or a crosslinking agent may be added.

As the crosslinking agent to be used, a compound usually used as a crosslinking agent can be used. Specifically, Shinzo Yamashita and Tosuke Kaneko, "Handbook for Crosslinking Agents," published by Taiseisha (19
81) The compounds described in "Polymer Data Handbook Basic Edition" edited by the Society of Polymer Science, Baifukan (1986) and the like can be used. For example, organic silane compounds (for example, vinyltrimethoxysilane, vinyltributoxysilane, γ-glycidoxypropyltrimethoxysilane,
γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane and other silane coupling agents), polyisocyanate compounds (for example, toluylene diisocyanate, O-toluylene diisocyanate, diphenylmethane diisocyanate, tri Phenyl methane triisocyanate, boli methylene phenyl isocyanate, hexamethylene diisocyanate, isophorone diisocyanate, high molecular weight polyisocyanate, etc.), polyol compounds (eg 1,4-butanediol, polyoxypropylene glycol, poly Oxyalkylene glycol, 1,1,1-trimethylolpropane, etc., polyamine compounds (eg, ethylenediamine, γ-hydroxypropylated ethylenediamine, phenylenediamine, hexamethylenediene) Min, N-aminoethylpiperazine, modified aliphatic polyamines, etc.) Polyepoxy group-containing compounds and epoxy resins (for example, Hiroshi Kakiuchi's "New Epoxy Resin", Shokoido (1985), Kuniyuki Hashimoto's "Epoxy Resin") Compounds described in Nikkan Kogyo Shimbun (1969), etc.), melamine resins (eg, compounds described in "Uria Melamine Resin" edited by Ichiro Miwa and Hideo Matsunaga, Nikkan Kogyo Shimbun (1969)) , Polyfunctional monomer compounds containing two or more polymerizable double bond groups (eg, Ogawara Shin, Saegusa Takeo, Higashimura Toshinobu "Oligomer")
The compounds described in Kodansha (Published in 1976), Eizo Omori "Functional Acrylic Resin" Techno System (published in 1985) and the like are specifically listed as divinylbenzene, divinylglutaconate diester, vinyl methacrylate and methacryl. Acid acrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate,
There are pentaerythritol polyacrylate, bisphenol A-diglycidyl ether diacrylate, oligoester acrylate: these methacrylates, etc.).

When the resin [B] is a resin containing a photocrosslinking functional group, a sensitizer, a photopolymerizable monomer or the like may be added. Specifically, compounds and the like cited in the above-mentioned review on photosensitive resins can be used.

The binder resin of the present invention is crosslinked after the photosensitive layer forming material is applied using toluene. In order to carry out the cross-linking, for example, it is preferable that the drying condition is set to a high temperature and / or a long time, or the coating solvent is dried and then further heat-treated. For example, the treatment is performed at 60 ° C to 120 ° C for 5 to 120 minutes.

Further, in the case of a photosensitive layer-forming product in which a photo-crosslinkable resin is used in combination, it may be cross-linked by being irradiated with electron beams, X-rays, ultraviolet rays or plasma light after coating, not only during drying but also before or after it. Well, the reaction is further promoted by heating under the above drying conditions. When the above reaction accelerator is used in combination, the treatment can be performed under milder conditions.

Conventionally known resins can be used together with the resin used in the present invention. For example, the above-mentioned silicone resin, alkyd resin, vinyl acetate resin, polyester resin, styrene-butadiene resin, acrylic resin and the like can be mentioned. Specifically, Ryuji Kurita and Jiro Ishiwatari, Polymer, No. 17
Volume, p. 278 (1968), Harumi Miyamoto, Hidehiko Takei, Imaging, 1973 (No.8) p. 9, etc.

The resin used in the present invention and a known resin can be mixed at any ratio, but the content of the carboxyl group-forming functional group-containing resin in the total amount of the resin is about 0.5 to 70% by weight. Is appropriate.

When the above content in the total amount of resin is less than 0.5% by weight,
The obtained lithographic printing plate precursor is not sufficiently hydrophilic due to the desensitizing treatment with a desensitizing solution / fountain solution, and stains are generated during printing.

On the other hand, if it is more than 70% by weight, the image formability at the time of copying is not good, and the film strength of the photoconductive layer at the time of printing is weakened and the durability is deteriorated.

The resin [A] containing at least one carboxyl group-forming functional group of the present invention is hydrolyzed or hydrogenolyzed by a desensitizing solution or a fountain solution used for printing to form a carboxyl group. Therefore, when the resin is used as the binder resin of the lithographic printing plate precursor as described above, the hydrophilicity of the non-image area which is made hydrophilic by the desensitizing solution is further enhanced by the carboxyl group generated in the resin. Therefore, the lipophilicity of the image area and the hydrophilicity of the non-image area become clear,
Prevents printing ink from adhering to non-image areas during printing.

When the resin [A] of the present invention is further used in combination with the resin [A], a crosslinking reaction occurs with the resin [A] of the present invention.

On the other hand, the carboxyl group-containing resin [A], which is generated by being decomposed by the dampening water during the etching treatment and printing on the printing machine, becomes hydrophilic, and when the content is large, it is usually water-soluble.

At this time, since the resin [A] forms a crosslinked structure with the non-aqueous resin [B] used in combination according to the present invention, the solubility in water is significantly reduced while the hydrophilicity is maintained, and the poor solubility Or it becomes insoluble.

Therefore, it is assumed that the hydrophilicity of the non-image area is further enhanced by the carboxyl group generated in the resin, and the durability is improved.

More specifically, even if the amount of the resin [A] contained in the entire binder resin is reduced, the effect of improving the hydrophilicity can be maintained without change, or the size of the printing machine can be increased or the printing pressure can be changed. Even when the printing conditions are severe, it is possible to print a large number of prints with clear image quality without scumming.

The lithographic printing plate precursor of the present invention has a ratio of 10 to 60 parts by weight of the above-mentioned binder resin to 100 parts by weight of photoconductive zinc,
It is preferably used in a proportion of 15 to 40 parts by weight.

In the present invention, various dyes can be used together as a spectral sensitizer, if necessary. For example, Harumiya Miyamoto, Hidehiko Takei, Imaging 1973 (No.8) Page 12, CJ Young, etc., RCA
Review 15 , 469 (1954), Kyohei Kiyota, Journal of The Institute of Electrical Communication J 63-C (No2), 97 (1980), Yuji Harazaki, etc., Journal of Industrial Chemistry 66 78 and 188 (1963), Tadaaki Tani, Nihon Photography Journal 3
5 , 208 (1972) and the like, carbonium dyes, diphenylmethane dyes, triphenylmethane dyes, xanthene dyes, phthalein dyes, polymethine dyes (eg, oxonol dyes, merocyanine dyes, cyanine dyes, rhodacyanine dyes, styryl dyes) And the like, and phthalocyanine dyes (which may contain metals).

More specifically, examples of those mainly using a carbonium dye, a triphenylmethane dye, a xanthene dye, and a phthalein dye are described in JP-B-51-452 and JP-A-50-9.
0334, JP-A-50-114227, JP-A-53-39130, JP-A-53-82353, U.S. Pat.No. 3,052,540, U.S. Pat.No. 4,0
54,450, those described in JP-A-57-16456, and the like.

As polymethine dyes such as oxonol dyes, merocyanine dyes, cyanine dyes and rhodacyanine dyes, F.
M. Harmmer `` The Cyanine Dyes and Related Compound
s '' and the like can be used, and more specifically, U.S. Pat.No. 3,047,384, U.S. Pat.No.3,110,591,
U.S. Patent 3,121,008, U.S. Patent 3,125,447, U.S. Patent 3,128,179, U.S. Patent 3,132,942, U.S. Patent 3,622,317, U.K. Patent 1,226,892, U.K. Patent 1,
No. 309,274, UK Patent No. 1,405,898, JP-B-48-7814
And the dyes described in JP-B-55-18892.

Further, as a polymethine dye for spectrally sensitizing the near-infrared to infrared light region having a long wavelength of 700 nm or more, JP-A-47-840, JP-A-47-44180, JP-B-51-41061, Sho 49-5034,
JP-A-49-45122, JP-A-57-46245, JP-A-56-35141
No., JP-A-57-157254, JP-A-61-26044, JP-A-61-26044
27551, U.S. Pat.No. 3,619,154, U.S. Pat.No. 4,175,95
No. 6, "Research Disclosure", 1982, 216, Nos. 117-11
Those described on page 8 and the like can be mentioned. The photoconductor of the present invention is excellent in that the performance thereof hardly changes depending on the sensitizing dye even when various sensitizing dyes are used in combination. 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 article: Imaging 1973 (No. 8), page 12, etc. review electron-accepting compounds (eg halogen, benzoquinone, chloranil, acid anhydrides, organic carboxylic acids, etc.), Hiroshi Komon, et al. Development and Practical Use of Photoconductive Materials and Photoconductors "Chapters 4 to 6: Review of Japanese Science Information Co., Ltd. (1986), polyarylalkane compounds, hindered phenol compounds, p-phenylene Examples thereof include diamine compounds.

The addition amount of these various additives is not particularly limited, but is usually 0.0001 to 2.0 parts by weight with respect to 100 parts by weight of the photoconductor.

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

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

The photoconductive layer according to the present invention can be provided on a conventionally known support. Generally speaking, the support of the electrophotographic photosensitive layer is preferably conductive, and as the conductive support, just as in the conventional case, for example, a metal, paper, a plastic sheet or the like substrate having a low resistance property is used. Conductive treated by impregnating, coated with at least one layer for the purpose of imparting conductivity to the back surface of the substrate (the surface opposite to the surface on which the photosensitive layer is provided) and further preventing curling, Water-resistant adhesive layer provided on the surface of the body, at least one precoat layer provided on the surface layer of the support, if necessary, laminate of electroconductive plastic substrate onto which Al or the like is vapor-deposited on paper It can be used.

Specifically, as an example of a conductive substrate or a conductive material, Yukio Sakamoto, Electrophotography, 14, (No1), p2 ~ 11 (1975),
Hiroyuki Moriga, “Chemistry of Introductory Special Papers” Polymer Publishing Association (197
5), MFHoover, J. Macromol. Sci. Chem. A-4 (6), No.
Those described on pages 1327 to 1417 (1970) and the like are used.

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

Example 1 64 g of n-propyl methacrylate, the following compound (A) 45
After heating a mixed solution of g, 1.0 g of acrylic acid and 400 g of toluene to a temperature of 70 ° C. under a nitrogen stream, 2,2′-azobis (2,4
-Dimethylvaleronitrile) (V-65) (1.5 g) was added and the reaction was carried out for 8 hours. The weight average molecular weight (w) of the obtained copolymer [A] -1 was 43,000.

Subsequently, 15 g of this copolymer as a solid content and [butyl methacrylate / allyl methacrylate (80/20) weight ratio] copolymer [B] -1 (w 36,000) 25 g, zinc oxide 200 g, rose bengal 0.03 g, tetra Bromphenol blue 0.01g and maleic anhydride 0.01g and toluene 30
0 g of the mixture was dispersed in a ball mill for 2 hours, and the dispersion was further mixed with 10 g of allyl methacrylate and 0.5 g of AIBN.
Was added and dispersed by a ball mill for 10 minutes to prepare a photosensitive layer-formed product, which was coated on a conductive-treated paper with a wire bar so that the dry adhesion amount was 20 g / m ^2, and dried at 100 ° C for 1 hour. did. Then, by leaving it in the dark at 20 ° C. and 65% RH for 24 hours, an electrophotographic photosensitive material was prepared.

In the above Production Example, three kinds of comparative photosensitive materials A, B and C were prepared by replacing the photosensitive layer forming material with the following copolymers.

Comparative photosensitive material A: n-propyl methacrylate 54 g, the compound (A) 45
A mixed solution of g, 1.0 g of acrylic acid and 400 g of toluene was heated to a temperature of 70 ° C. under a nitrogen stream, 1.5 g of V-65 was added, and the mixture was reacted for 8 hours. The obtained copolymer [A] -2 had a w of 40,000.
Met. Subsequently, 40 g of this copolymer as solid content, 200 g of zinc oxide, 0.03 g of rose bengal, 0.01 g of tetrabromophenol blue and 0.01 g of maleic anhydride and toluene.
300 g of the mixture was dispersed in a ball mill for 2 hours to prepare a photosensitive layer-forming material, which was dried on a conductive paper to give a dry adhesion amount of 20.
It was coated with a wire bar so as to be g / m ² and dried at 100 ° C. for 1 minute. Then, by leaving it in the dark at 20 ° C. and 65% RH for 24 hours, an electrophotographic photosensitive material was prepared.

Comparative Photosensitive Material B: In Comparative Example A, instead of Resin [A] -2,
[A] -1,15 g and [butyl methacrylate / n-propyl methacrylate (80/20) weight ratio] copolymer [B-
2] A light-sensitive material was prepared in the same manner as in Comparative Example A except that 25 g of w40,000) was used.

Comparative photosensitive material C: In Comparative Example A, instead of the resin [A] -2, [butyl methacrylate / n-propyl methacrylate / acrylic acid (80/19/1) weight ratio] copolymer [B] -3 (W3
A light-sensitive material was prepared in the same manner as in Comparative Example A except that 40 g of 8,000) was used.

The film properties (surface smoothness), electrostatic properties, desensitization property of the photoconductive layer (expressed by the contact angle of the photoconductive layer with water after desensitization treatment) and printability of these photosensitive materials are examined. Was. Printability is fully automatic plate making machine ELP404V (Fuji Photo Film Co., Ltd.)
(Manufactured) was exposed and developed with a developer ELP-T to form an image, and the desensitizing liquid ELP-E was used to perform etching with an etching processor. The printing machine used was a Hamada Star 800SX type manufactured by Hamada Star Co., Ltd.).

 Table 1 summarizes the above results.

The embodiments of the evaluation items described in Table 1 are as follows.

Note 1) Smoothness of photoconductive layer: Using the Beck smoothness tester (manufactured by Kumagai Riko Co., Ltd.), the smoothness (sec / cc) of the obtained photosensitive material was measured under the condition of an air capacity of 1 cc. It was measured.

Note 2) Electrostatic characteristics: A paper analyzer (Kawaguchi Electric Co., Ltd. paper analyzer) was applied to each photosensitive material in a dark room at a temperature of 20 ° C and 65% RH.
(SP-428 type) was used for corona discharge at −6 KV for 20 seconds and then left for 10 seconds, the surface potential V _o at this time was measured, and then the surface of the photoconductive layer was irradiated with visible light with an illuminance of 2.0 lux. , The time until the surface potential V _o decays to 1/10 is obtained, and the exposure amount E1 / 10 (lux · sec) is calculated from this.

Note 3) Contact angle with water: Each photosensitive material was passed through an etching processor once with a desensitizing solution ELP-E (manufactured by Fuji Photo Film Co., Ltd.) to desensitize the photoconductive layer surface. After that, a drop of distilled water (2 μl) is put on this, and the contact angle with the formed water is measured with a goniometer.

Note 4) Image quality of copied image: Each photosensitive material and fully automatic plate-making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.) are left at room temperature and humidity (20 ° C, 65%) for one day, and then plate-made to make a copied image. And an image (fog, image quality) of the obtained copy original plate is visually observed (this is referred to as I). The image quality II of the copied image is tested by the same method as the above I except that the plate making is performed at high temperature and high humidity (30 ° C., 80%).

Note 5) Background stain of printed matter: Each light-sensitive material is subjected to plate-making with a fully automatic plate-making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.) to form a toner image, and desensitized under the same conditions as the above-mentioned Note 3). This is used as an offset master in an offset printing machine (Hamada Star 800SX type manufactured by Hamada Star Co., Ltd.) to print 500 sheets on high-quality paper, and the background stain of all prints is visually determined. This is referred to as background smear I of the printed matter.

The background stain II of the printed matter is the same as the background stain I except that the desensitizing treatment liquid is diluted 5 times and the immersion water at the time of printing is diluted 2 times. Is strengthened and the test is performed, and the number of prints until the background stain occurs is evaluated.

The case of II corresponds to printing under more severe conditions than I.

The copied images obtained using the light-sensitive materials of the present invention and Comparative Examples A and B were both clear image quality, and Comparative Example C had deteriorated smoothness of the photoconductive layer surface. Further, in Comparative Example C in which each light-sensitive material was plate-formed in an environment of (30 ° C., 80%), the copied image was remarkably deteriorated (ground fog was generated and the image density was 0.6 or less. ).

Further, the contact angle with water of each light-sensitive material subjected to the desensitizing treatment with the desensitizing solution was as small as 15 ° or less except for Comparative Example C, which means that it was sufficiently hydrophilized.

Further, when printing these as master plates for offset printing, the good plates which did not cause background stains in non-image areas were the plates of the present invention, Comparative Example A and Comparative Example B. Further, when these plates were printed by forcing the printing pressure condition of the printing machine, the image quality of the printed matter was good and no scumming occurred even after printing 10,000 plates of the present invention.
The plate of Comparative Example A has 5000 plates and the plate of Comparative Example B has 75 plates.
Print stains occurred on the 00 printed sheet.

After the photosensitive material of the present invention was left under the environmental condition of (45 ° C. and 75% RH) for 2 weeks, the electrophotographic characteristics and the printing practical characteristics were measured in the same manner as above, but it showed almost no change.

Examples 2 to 13 In place of the resin used in Example 1, 12 g of each of the copolymers in Table 2 as the resin [A] of the present invention and [benzyl methacrylate / vinyl methacrylate (75/25) as the resin [B]. Weight Ratio] Each light-sensitive material of the present invention was produced in the same manner as in Example 1 except that the copolymer [B-1] ′ 28 g was used.

When this was subjected to plate making using the same apparatus as in Example 1, the density of the obtained offset printing master plate was 1.0 or more, and the image quality was clear. Furthermore, after etching and printing with a printing machine, the printed matter after printing 10,000 sheets had a clear image quality without fog.

Further, this light-sensitive material was left under the environmental conditions of (45 ° C., 75% RH) for 2 weeks and then subjected to the same processing, but there was no difference from that before the passage of time.

Examples (14 to 16) As a resin [A], 20 g of a copolymer having the following copolymerization composition ratio (weight ratio) and As the resin [B], except that the copolymer shown in Table 3 was 22 g each, the composition similar to that of Example 1 was dispersed in a ball mill for 2 hours to prepare a photosensitive layer-formed product, which was subjected to a conductive treatment. Apply it with a wire bar so that the dry adhesion amount will be 25 g / m ² .
An electrophotographic photosensitive material was prepared by drying at 105 ° C. for 1 hour and then leaving it in the dark at 20 ° C. and 65% RH for 24 hours.

When this was subjected to plate making using the same apparatus as in Example 1, the density of the obtained offset printing master plate was 1.0 or more, and the image quality was clear. Further, after etching and printing with a printing machine, the printed matter after printing 10,000 sheets had clear image quality without fog.

Example 17 A photosensitive material was prepared in the same manner as in Example 14, except that the resins shown in Table 4 were changed to 22 g and 18 g, respectively, as the resin [A] and the resin [B].

When a plate was prepared using the same apparatus as in Example 1, the obtained master plate for offset printing had a density of 1.0 or more and the image quality was clear. Further, after etching and printing with a printing machine, the printed matter after printing 10,000 sheets had clear image quality without fog.

Further, this light-sensitive material was allowed to stand for 2 weeks under an environmental condition of (45 ° C., 75% RH) and then subjected to the same processing, but there was no difference from that before the passage of time.

Example 18 Resin [A] -5 15 g as Resin [A] and Resin [B] ([B] -8) 25 having the following structure as Resin [B] 25
A light-sensitive material was prepared in the same manner as in Example 14 except that g was used.

When a plate was prepared using the same apparatus as in Example 1, the obtained master plate for offset printing had a density of 1.0 or more and the image quality was clear. When the product was further etched and printed by a printing machine, the printed matter after printing 10,000 sheets was a clear image without fog.

Further, this light-sensitive material was allowed to stand for 2 weeks under an environmental condition of (45 ° C., 75% RH) and then subjected to the same processing, but there was no difference from that before the passage of time.

(Effects of the Invention) According to the present invention, an original plate for electrophotographic lithographic printing having excellent background stain and printing durability can be obtained.

Claims (1)

[Claims] 1. An electrophotographic photoreceptor comprising a photoconductive layer provided by coating a liquid containing at least photoconductive zinc oxide, the following resin (A), the following resin (B) and toluene on a conductive support. Original plate for lithographic printing using. (I) Resin (A): a copolymerization component containing at least one functional group capable of generating at least one carboxyl group by decomposition and a copolymerization component containing at least one functional group capable of undergoing a crosslinking reaction with the resin [B]. (Ii) Resin (B): a methacrylate copolymer containing at least one component containing at least one functional group capable of undergoing a curing reaction with heat and / or light.