JP2606950B2 - Printing plate for electrophotographic plate making - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention has a photoconductive layer containing an organic photoconductive compound, and forms a non-image other than a toner image portion after forming a toner image by electrophotography. The present invention relates to a printing plate precursor for electrophotographic plate making, which is a printing plate by removing a part of the photoconductive layer, and more particularly to a printing plate precursor for electrophotographic plate making with improved photoresponsiveness and printability.

[Conventional technology]

Today, as a lithographic offset printing plate, a positive type photosensitizer mainly composed of a diazo compound and a phenol resin, and a PS plate using a negative type photosensitizer mainly composed of an acrylic monomer or a prepolymer have been commercialized. However, since all of these methods have low sensitivity, plate making is carried out by closely exposing a film master on which an image has been recorded in advance.

On the other hand, due to advances in computer image processing, large-capacity data storage, and data communication technology, in recent years, computer operations have been consistently performed from document input, correction, editing, layout to page set, and real-time remote An electronic editing system that can output to the end plotter has been put to practical use. In particular, the demand for an electronic editing system is high in the newspaper printing field, which requires immediacy. Also, in the field where originals are stored in the form of original films and printing plates are duplicated as necessary, with the development of ultra-high-capacity recording media such as optical disks, the originals can be stored on these recording media digitally. It is thought that it will be saved as data.

However, direct-type printing plates that produce printing plates directly from the output of the terminal plotter have hardly been put to practical use, and output is performed on silver halide photographic film even when the electronic editing system is operating. Indirectly to
The reality is that a printing plate is created by contact exposure to the PS plate. This is because the light source of the output plotter (for example, He-
One of the reasons is that it is difficult to develop a direct printing plate having a sensitivity high enough to produce a printing plate within a practical time using a Ne laser, a semiconductor laser, or the like.

An electrophotographic photoreceptor is considered as a photoreceptor having high photosensitivity capable of providing a direct printing plate. Many types of electrophotographic printing plate precursors that remove the photoconductive layer in the non-image area after forming a toner image are already known. For example, Japanese Patent Publication Nos. 37-17162, 38-6696, 38-7758, and 41-2
Nos. 426 and 46-39405, JP-A-50-19509 and 50-195
No. 10, No. 52-2437, No. 54-145538, No. 54-134632
Nos. 55-105254, 55-153948, 55-161250
And the electrophotographic printing plate precursors described in JP-A-57-147656 and JP-A-57-161863.

In order to use an electrophotographic photoreceptor as a printing plate, it is necessary to remove the non-image area by etching to expose the hydrophilic surface, so that the binder resin is dissolved in an alkaline solvent or swells and is released. Often a binding resin is used. In general, resins soluble or dispersed in these alkaline solvents have poorer compatibility with organic photoconductive compounds than polycarbonate resins widely used as binder resins for electrophotographic photoreceptors. The amount of the hydrophilic compound introduced into the electrophotographic photosensitive layer is limited. Even if sufficient carriers are generated to cancel the surface potential in the photoconductive layer, if the content of the organic photoconductive compound in the photoconductive layer is low, the moving speed of the carriers in the photoconductive layer is reduced. And the decay rate of the surface potential, that is, the response speed decreases. For this reason, after the exposure is completed, the surface potential is sufficiently attenuated so as not to give fog, and the time required for starting the toner development is increased. In order to shorten the process time as much as possible, the response time becomes longer as the exposure illuminance is increased and the exposure time is shortened. Therefore, the slow response speed is a major hindrance to reducing the overall process time.

Another problem arises when scanning exposure is performed using a high illuminance light source such as a laser light source. That is, if the response speed is low, the attenuation rate of the surface potential is different between the writing start portion and the writing end portion, so that there is no fog at the writing start portion, but an image with much fog is formed at the writing end portion. This causes development which causes inconvenience in the production of.

Conventionally known binder resins used in electrophotographic printing plate precursors include JP-B Nos. 41-2426 and 37-17162.
No. 38-6961, JP-A No. 52-2437, and No. 54-19803
Nos. 54-134632, 55-105254, 50-19509
And styrene-maleic anhydride copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-maleic anhydride copolymers, phenolic resins, and the like described in JP-A Nos. 1910 and 19510 are known.

However, it is already known that when these are used in a printing original plate for electrophotographic plate making using an organic photoconductive compound, they have various problems. That is,
When a styrene-maleic anhydride copolymer is used as the binder resin, the formed film is hard and cracks may occur when the printing plate is curved. In addition, the film has poor adhesion and cannot withstand printing on a large number of sheets. When a phenol resin is used as the binding resin, the formed film is fragile and the printing durability is poor. The vinyl acetate-crotonic acid copolymer and the vinyl acetate-maleic anhydride copolymer also had a problem in printing durability.
Further, these resins were insufficient in electrophotographic properties (especially charge retention in darkness, photosensitivity).

As a solution to the above problems, Japanese Patent Laid-Open No.
Nos. 1863 and 58-76843 disclose copolymers of acrylate monomer or methacrylate monomer and carboxylic acid-containing monomer. If these binding resins are used, it can be used as a printing original plate for electrophotographic plate making.

However, as described above, the problem that has recently been pointed out (i.e., lack of photosensitivity) due to the slow response speed has not been solved yet.

Furthermore, it is said that printing durability and light sensitivity have been improved.
No. 209458 discloses, as a binding resin, a copolymer of an aromatic ring-containing acrylate or methacrylate and an acidic group-containing monomer such as carboxylic acid. The use of these binder resins improves the performance described above, but there is a problem in that the removability of the photoconductive layer in the non-image portion other than the toner image portion does not easily progress,
It turned out that strict control of the conditions for removal was necessary.

In other words, the conditions for producing a printing plate in which faithful reproduction of a copied image in which only the non-image portion is completely removed without performing elution even in a toner image portion having a very small area, and in which no printing background smear occurs are satisfied. The problem of being narrow was unresolved.

[Problems to be solved by the invention]

A first object of the present invention is to provide an electrophotographic printing plate precursor having good electrophotographic properties and good dissolution of non-image areas.

A second object of the present invention is to provide an electrophotographic printing plate precursor suitable for image formation using scanning line light such as a laser.

A third object of the present invention is to provide an electrophotographic printing plate precursor having excellent printing durability.

[Means for solving the problem]

The above-mentioned problem is that a photoconductive layer containing at least a photoconductive compound and a binding resin is provided on a conductive support, and after image exposure and formation of a toner image, the photoconductive layer of a non-image portion other than the toner image portion is formed. A printing original plate for electrophotographic plate making, which is used as a printing original plate by removing a layer, wherein at least one of the following resins is contained as a binder resin of the photoconductive layer, which is achieved in the printing original plate for electrophotographic plate making. Is done.

Binder resin: a monofunctional macromonomer having a polymerizable double bond group represented by the following general formula [I] bonded only to one end of the polymer main chain, and having a weight average molecular weight of 2 × 10 ⁴ A monofunctional macromonomer containing at least one polymer component represented by the following general formula [IIa] or [IIb]; and a monomer represented by the following general formula (III); a monofunctional monomer, -PO ₃ H ₂ group, -SO ₃
H group, -COOH group, phenolic -OH group, ｛R represents a monofunctional monomer containing at least one acidic group selected from｝ groups representing a hydrocarbon group or an —OR ′ group (R ′ represents a hydrocarbon group) and a cyclic acid anhydride-containing group. A graft copolymer having a weight average molecular weight of 1 × 10 ³ to 1 × 10 ^{5 as} a component.

General formula (I) 中 In the formula (I), A ₀ represents —COO—, —OCO—, — (CH ₂ ) _L1 OCO
_{-, - (CH 2) L2} COO -, ( an integer of _{L1, L2} is 1~3), - O -, - SO 2 -, - CO-, -CONHCOO-, -CONHCONH-, or (Where R ₁ represents a hydrogen atom or a hydrocarbon group).
a ₁ and a ₂ may be the same or different, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, -COO-D ₁
Or -COO-D ₁ via a hydrocarbon (D ₁ represents a hydrogen atom or a hydrocarbon group which may be substituted). ｝ General formula (IIa) General formula (IIb) {Wherein (II a) or (II b), A ₁ represents the same content as A ₀ in formula (I). B ₁ represents an aliphatic group having 1 to 18 carbon atoms or an aromatic group having 6 to 12 carbon atoms.

b ₁ and b ₂ may be the same or different, and represent the same contents as a ₁ and a ₂ in the formula (I). B ₀ is -CN, -CONH ₂ or And J represents a hydrogen atom, a halogen atom, an alkoxy group or —COOD ₄ (D ₄ represents an alkyl group, an aralkyl group or an aryl group). ｝ General formula (III) {Wherein (III), A ₂ represents the same content as A ₁ in formula (II a), B ₂ represents a B ₁ same contents as in formula (II a). c ₁ and c ₂ may be the same or different from each other;
It represents the same contents as a ₁ and a ₂ in the table. That is, the binding resin (hereinafter, referred to as binding resin [A]) used in the present invention is a monofunctional macromonomer {hereinafter referred to as monomer (MA)) and a monomer represented by general formula (III)}. It is a graft copolymer having, as at least components, a monomer (A) and a monomer containing a group in which a specific acidic group is selected (monomer (B)).

The binding resin [A] used in the present invention is a benzene ring or naphthalene having a specific substituent at the 2-position or the 2,6-position represented by the following general formulas (Va) and (Vb). It is preferably an acidic group-containing resin containing a methacrylate component having a specific substituent having a ring.

General formula (V a) General formula (V b) ｛In the formulas (Va) and (Vb), G ₁ and G ₂ are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a chlorine atom,
A bromine atom, -col ₁ or -COOL ₂ (L ₁ and L ₂ each represents a hydrocarbon group having 1 to 10 carbon atoms) represent. Z ₁ and Z ₂ each represent a direct bond or a linking group having 1 to 4 linking atoms, each linking —COO— and a benzene ring.結合 Furthermore, the binding resin of the present invention is a resin comprising the above-mentioned specific acidic group bonded only to one end of the polymer main chain of the graft copolymer (hereinafter referred to as “binding resin [A ′])”. It is preferred that

The binding resin [A] of the present invention (including the binding resin [A '])
Has a weight average molecular weight of 1 × 10 ³ to 1 × 10 ⁵ , preferably 3 × 10 ^{3 to} 5 × 10 ⁴ , and more preferably 5 × 10 ^3.
２2 × 10 ⁴ .

Monofunctional macromonomers (M) containing at least one of the polymer components represented by the general formulas (IIa) and (IIb)
The content of A) in the binding resin [A] is 3% by weight.
-60% by weight, preferably 5-40% by weight.

The proportion of the monomer (A) represented by the general formula (III) in the binding resin [A] is 20% by weight to 92% by weight, preferably 30% by weight to 85% by weight.

In the binding resin [A], the formula (Va) and / or (V
The proportion of the methacrylate copolymer component corresponding to the repeating unit of b) is from 20% by weight to 92% by weight, preferably 30% by weight.
% To 85% by weight.

The content of the acidic group-containing monomer (B) in the binder resin [A] is 5 to 50% by weight, preferably 10 to 40% by weight per 100 parts by weight of the binder resin [A]. is there.

Further, in the binding resin (A ') in which the acidic group is bound to one end of the polymer main chain of the graft copolymer of the present invention,
The proportion of the acidic group-containing binding component is from 0.5% by weight to 20% by weight per 100 parts by weight of the binding resin [A '];
Preferably it is 1% to 10% by weight.

Further, the glass transition point of the binder resin [A] and the binder resin [A '] is from 10 ° C to 140 ° C, preferably from 20 ° C to 120 ° C.

When the molecular weight of the binding resin [A] is less than 1 × 10 ³ , the film-forming ability is reduced and sufficient film strength cannot be maintained.
If the molecular weight is larger than 1 × 10 ⁵ , the dissolution of the non-image area will be reduced.

When the total amount of the acidic group-containing components of the monomer (B) and the terminal acidic group-containing component in the binder resin [A] is less than 5% by weight, the dissolution of the non-image area is reduced. On the other hand, when the total content of the acidic group is more than 50% by weight, high temperature / high humidity,
Under severe conditions such as low temperature and low humidity, the electrostatic characteristics are degraded (initial potential, charge retention in darkness, photosensitivity, etc.), and a sufficient copied image cannot be obtained.

If the amount of the copolymer component corresponding to the macromonomer (MA) is 3% by weight or less, the effect of entanglement between the polymer chains is weakened because the graft portion is too small, and the effect of improving the printing durability is lost. On the other hand, if it exceeds 60% by weight, the copolymerization with the monomer (A) does not proceed sufficiently, and in addition to the desired graft copolymer, a polymer of the monomer of general formula (III) or other monomer alone Are formed, which is not preferable.

Next, each component in the graft copolymer of the present invention will be described in detail.

Monofunctional macromonomer (MA) used in the present invention
Is one of a polymer main chain containing a polymerizable double bond group represented by the general formula (I) and at least one of polymer components represented by the general formulas [IIa] and [IIb]. Having a weight-average molecular weight of 2 × 10 ⁴ or less.

In the general formulas (I), (IIa) and (IIb), a ₁ ,
The hydrocarbon groups contained in a ₂ , A ₀ , b ₁ , b ₂ , A ₁ , B ₁ and B ₀ each have the indicated carbon number (as an unsubstituted hydrocarbon group). The hydrogen group may have a substituent.

 The macromonomer (MA) will be described.

In the general formula (I), A ₀ represents -COO-, -OCO-,-
_{(CH 2) L1 OCO -,} - (CH 2) L2 COO - O -, - SO 2 -,
-CO-, -CONHCOO-, -CONHCONH-, or Represents

Here _{L1, L2} represents an integer of 1 to 3, R ₁ except hydrogen atom, preferably an optionally substituted alkyl group (e.g. methyl 1 to 6 carbon atoms as the hydrocarbon groups include ethyl, propyl, butyl , Heptyl, hexyl, 2-chloroethyl, 2-bromoethyl, 2-cyanoethyl, 2-methoxycarbonylethyl, 2-methoxyethyl, 3-bromopropyl), an alkenyl group having 4 to 8 carbon atoms which may be substituted (for example, 2 -Methyl-1-propenyl, 2-butenyl, 2-pentenyl, 3-methyl-2-pentenyl, 1
-Pentenyl, 1-hexenyl, 2-hexenyl, 4-
Methyl-2-hexenyl), an optionally substituted aralkyl group having 7 to 14 carbon atoms (for example, benzyl, phenethyl, 3
-Phenylpropyl, naphthylmethyl, 2-naphthylethyl, chlorobenzyl, bromobenzyl, methylbenzyl, ethylbenzyl, methoxybenzyl, dimethylbenzyl, dimethoxybenzyl), an optionally substituted alicyclic group having 5 to 8 carbon atoms ( For example, cyclohexyl, 2-cyclohexylethyl, 2-cyclopentylethyl), or
An optionally substituted aromatic group having 6 to 12 carbon atoms (eg, phenyl, naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl , Dichlorophenyl, bromophenyl, cyanophenyl, acetylphenyl, methoxycarbonylphenyl, ethoxycarbonylphenyl, butoxycarbonylphenyl,
Acetamidophenyl, propioamidophenyl, dodecylylamidophenyl).

A ₀ In the case where is represented, the benzene ring may have a substituent. Examples of the substituent include a halogen atom (eg, chlorine, bromine), an alkyl group (eg, methyl, ethyl, propyl, butyl,
Chloromethyl, methoxymethyl), and alkoxy groups (eg, methoxy, ethoxy, propoxy, butoxy) and the like.

a ₁ and a ₂ may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, chlorine, bromine), a cyano group, or an alkyl group having 1 to 4 carbon atoms (eg, methyl, ethyl, propyl, butyl) ), -COO-D ₂ , or COOD ₂ via a hydrocarbon (D ₂ is a hydrogen atom or a carbon atom
-14 represents an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group or an aryl group, which may be substituted, and specifically represents the same contents as those described for R ₁ above) Represents

The hydrocarbon group in -COO-D ₂ group via the hydrocarbon, a methylene group, an ethylene group and a propylene group.

More preferably, in the general formula (I), A ₀ is -CO
O -, - OCO -, - CH 2 OCO -, - CH 2 COO -, - O -, - CO
_{NH -, - SO 2 NH -} , - CONHCOO -, - CONHCONH- or A ₁ and a ₂ may be the same or different from each other, and represent a hydrogen atom, a methyl group, —COOD ₃ or —CH ₂ COD ₃ (D ₃ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (eg, Represents a methyl, ethyl, propyl, butyl, hexyl) group. Even more preferably, _one of a ₁ and a ₂ represents a hydrogen atom.

That is, as the polymerizable double bond group represented by the general formula (I), specifically, CH ₂ CHCH—SO ₂ — and the like.

In the general formula (IIa) or (IIb), A ₁ is a group represented by the formula (I)
Represents the same content as A _{0 in} . b ₁ and b ₂ may be the same or different, and represent the same contents as a ₁ and a ₂ in the formula (I).

B ₀ represents an aliphatic group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms.

Specifically, an alkyl group having 1 to 6 carbon atoms which may be substituted (for example, methyl, ethyl, propyl, butyl, heptyl, hexyl, 2-chloroethyl, 2-bromoethyl, 2-hydroxyethyl, 2-methoxyethyl, 2
-Ethoxyethyl, 2-cyanoethyl, 3-chloropropyl, 2- (trimethoxysilyl) ethyl, 2-tetrahydrofuryl, 2-thienylethyl, 2-N, N-dimethylaminoethyl, 2-N, N-diethylaminoethyl ),
A cycloalkyl group having 5 to 8 carbon atoms (eg, cycloheptyl, cyclohexyl, cyclooctyl);
Optionally substituted aralkyl groups such as benzyl, phenethyl, 3-phenylpropyl, naphthylmethyl, 2
-Naphthylethyl, chlorobenzyl, bromobenzyl,
Dichlorobenzyl, methylbenzyl, chloro-methyl-
Aliphatic groups such as benzyl, dimethylbenzyl, trimethylbenzyl, and methoxybenzyl).

Further, an optionally substituted aryl group having 6 to 12 carbon atoms (eg, phenyl, tolyl, xylyl, chlorophenyl, bromophenyl, dichlorophenyl, chloro-methyl-phenyl, methoxyphenyl, methoxycarbonylphenyl, naphthyl, chloronaphthyl) and the like And aromatic groups.

In the formula (IIa), A ₁ is preferably -COO-, -OCO
_{-, - CH 2 COO -,} - CH 2 OCO -, - O -, - CO -, - CONH
-, -SO ₂ NH-, -CONHCOO-, -CONHCONH-, or Represents

Preferred examples of b ₁ and b ₂ represent the same contents as those of a ₁ and a ₂ described above.

In the formula (IIb), B ₁ represents —CN, —CONH ₂ or J represents a hydrogen atom, a halogen atom (eg, chlorine, bromine), an alkoxy group (eg, methoxy, ethoxy, propoxy, butoxy) or —COOD ₄ (D ₄ is preferably an alkyl group having 1 to 4 carbon atoms, Represents an aralkyl group or an aryl group of the formulas 7 to 12).

The macromonomer (MA) has the formula (IIa) and / or (II)
The polymer component represented by b) may be contained in two or more kinds. When B ₁ is an aliphatic group, the aliphatic group having 4 to 6 carbon atoms is preferably used in an amount not exceeding 20% by weight of the total polymer components in the macromonomer (MA).

Further, when A ₁ in the general formula (IIa) is —COO—, among all the polymer components in the macromonomer (MA),
At least 30% by weight of a polymer component represented by the formula (IIa)
It is preferable to contain the above.

Further, in the macromonomer (MA), as a monomer corresponding to another repeating unit copolymerizable with the polymer component represented by the formula (IIa) and / or (IIb), a heterocyclic vinyl (for example, Vinyl pyridine, vinyl imidazole, vinyl pyrrolidone, vinyl thiophene, vinyl pyrazole, vinyl dioxane, vinyl oxazine) and the like.

The macromonomer (MA) used in the binding resin [A] of the present invention is one of the polymer main chains composed of the repeating units represented by the general formulas (IIa) and / or (IIb) as described above. It has a chemical structure in which the polymerizable double bond group represented by the general formula (I) is directly bonded only at the terminal or bonded with an arbitrary linking group.

As a copolymerization method for linking the component of the formula (I) and the component of the formula (IIa) or (IIb), a carbon-carbon bond (single bond or double bond), a carbon-heteroatom bond (as a heteroatom, For example, oxygen, sulfur, suffocation, silicon, etc.), and any combination of heteroatom-heteroatom bond atomic groups.

Preferred among the macromonomers (MA) of the present invention are those represented by the following formula (IVa) or (IVb).

Formula (IVa) Equation (IV b) In the formulas (IV a) and (IV b), a ₁ , a ₂ , b ₁ , b ₂ , A ₀ ,
A ₁ , B ₀ and B ₁ are each represented by the formula (I), the formula (IIa) and the formula (II
Represents the same content as described in b).

G is a simple bond, or ｛R ₂ and R ₃ represent a hydrogen atom, a halogen atom (eg, fluorine,
Chlorine, bromine), cyano group, hydroxyl group, alkyl group (e.g., methyl, ethyl, propyl), etc.,-(CH = CH)-, -O-, -S-, -COO -, - SO ₂ -, -NHCOO-, -NHCONH-, ｛R ₄ is a single linking group selected from an atomic group such as｝ which represents a hydrogen atom, a hydrocarbon group having the same content as B ₁ in the formula (IIa), or an arbitrary combination thereof. Represents a linking group.

The weight average molecular weight of the macromonomer (MA) is 2 × 10 ⁴
If it exceeds 30, the copolymerizability with the monomer (A) is undesirably reduced. On the other hand, if the weight average molecular weight is too small, the effect of improving the electrophotographic properties of the photosensitive layer is reduced, so that the 1 ×
It is preferably 10 ³ or more.

The macromonomer (MA) of the present invention can be produced by a conventionally known synthesis method.

For example, a method according to an ionic polymerization method in which various reagents are allowed to react with terminals of a living polymer obtained by anionic polymerization or cationic polymerization to obtain a macromonomer,
Radical using a polymerization initiator and / or a chain transfer agent containing a reactive group such as a carboxyl group, a carboxylic acid chloride group, a hydroxyl group, an amino group, an epoxy group, a halogen atom (bromine atom or iodine atom) in a molecule. Polymerized,
A method of reacting the obtained oligomer having a terminal reactive group with various reagents to obtain a macromonomer by a radical polymerization method, and the like can be given.

Specifically, P.Dreyfuss & RPQuirk, Encycl, Poly
m.Sci.Eng., 7 , 551 (1987), PFRempp, E.Franta, Adu.,
Polym, Sci. 58 , 1 (1984), V. Percec, Appl., Polym, Sci., 2
85 , 95 (1984), R. Asami, M. Takari, Makromol. Chem. Supp
l. 12 , 163 (1985), P. Rempp. et al. Makromol. Chem. Suppl.
8 , 3 (1984), Yusuke Kawakami, Chemical Industry, 38 , 56 (198
7), Yuya Yamashita, Polymer, 31 , 988 (1982), Shiro Kobayashi, Polymer, 30 , 625 (1981), Toshinobu Higashimura, Journal of the Adhesion Society of Japan 18 , 536 (1982), Koichi Ito, Polymer processing, 35, 262 (19
86), Takashiro Higashi, Takashi Tsuda, Functional Materials, 1987 No. 10, 5, etc., and the methods described in the references and patents cited therein.

Specific examples of the macromonomer (MA) of the present invention include the following compounds. However, the scope of the present invention is not limited to these.

In the following examples, a ₁₁ and b ₁₁ each represent H or CH ₃ , b ₁₂ represents H, —CH ₃ or —CH ₂ COOCH ₃ , and R ₁₁ represents —C _i H _{2i + 1} (i = 18 integer), - CH ₂ C
_{6 H 5, -C 6 H 5} , or R ₁₂ represents -C _i H _{2i + 1} ,-(CH ₂ ) _j -C ₆ H ₅ (j is 1 to 3
Integer), or (J ₁ is -CH _3, -Cl, -Br or -OCH ₃₎ indicates, R _{13 is, -C i H 2i + 1,} -CH 2 C 6 H 5 or -C indicates ₆ H _5, R _14, -C _i H _{2i + 1} or indicates _{-CH 2 C 6 H 5, R} 15 _{is, -C i H 2i + 1,} -CH 2 C 6 H 5 or Are shown, R ₁₆ is, -C _i H _{2i + 1} indicates, E ₁ is -COOCH _3, shows a -C ₆ H ₅ or -CN, E _{2 is, -C i H 2i + 1,} -OCOC i H _{2i + 1} , -COOCH ₃ , -C ₆ H ₅
Or -CN, E ₃ is -COOCH ₃ , -C ₆ H ₅ , (J ₂ is -CH _3, -Cl or -Br) indicates or -CN, E ₄ represents -Cl, -Br, -F, and -OH or -CN, E ₅ is -OCOC _i H _{2i +1,} -CN, shows a -CONH ₂ or -C ₆ H _5, E ₆ are, -CN, shows a -CONH _2, or -C ₆ H _5, E ₇ is, -COOCH _3, -C ₆ H ₅ or Wherein J ₃ is H, -CH ₃ , -Cl, -Br, -OCH ₃ or -COO
CH ₃ is shown, and h represents an integer of 2 to 4.

As described above, the weight average molecular weight of the monofunctional macromonomer (MA) used in the present invention is 1 × 10 ³ to 2 × 10 ⁴ , preferably 3 × 10 ³ to 1 × 10 ⁴ .

When the weight average molecular weight is 1 × 10 ³ or less, the chain length of the graft portion as the graft copolymer becomes short, and the structure becomes similar to that of the conventional random copolymer.
The effect of improving the printing durability is diminished.

On the other hand, when the weight average molecular weight is 2 × 10 ⁴ or more, the copolymerizability of the macromonomer (MA) with the monomers (A) and (B) is reduced, and the weight of only a single polymer other than the graft copolymer is reduced. Coalescence is formed, which is not preferable.

The monomer (A) copolymerized with the above-mentioned macromonomer (MA) is represented by the general formula (III).

In formula (III), c ₁ and c ₂ may be the same or different from each other, and represent the same contents as a ₁ and a ₂ in formula (I), and more preferably represent a hydrogen atom or a methyl group. A ₂ has the formula (II
and A ₁ in a), B ₂ represents the same content each and B ₁ in formula (II a).

More preferably, a methacrylate monomer represented by the following general formula (V) {in the formula (III), C ₁ represents a hydrogen atom, C ₂ represents a methyl group, and A ₂ represents —COO
In the case of-, the following is referred to as a monomer A '.
contains.

General formula (V) Further, preferably, the copolymer component corresponding to the repeating unit of the general formula (III) is a compound represented by the general formula (Va) and / or (V
It is represented by a methacrylate component containing a specific aryl group shown in b).

General formula (V a) General formula (V b) In the formula (Va), as preferred G ₁ and G ₂ , in addition to a hydrogen atom, a chlorine atom and a bromine atom, respectively, as a preferred hydrocarbon group, an alkyl group having 1 to 4 carbon atoms (eg, methyl, ethyl, propyl) Butyl), having 7 to 7 carbon atoms
9 aralkyl groups (eg benzyl, phenethyl, 3-
Phenylpropyl, chlorobenzyl, dichlorobenzyl, bromobenzyl, methylbenzyl, methoxybenzyl, chloro-methyl-benzyl) and aryl groups (eg, phenyl, tolyl, xylyl, bromophenyl, methoxyphenyl, chlorophenyl, dichlorophenyl),
And -COL ₁ and -COOL ₂ (preferable L ₁ and L ₂ include those described as preferable hydrocarbon groups above).

In the formula (Va), Z ₁ is a single bond connecting —COO— and a benzene ring, or — (CH ₂ ) _n1 — (n ₁ represents an integer of ₁ to 3), —CH ₂ OCO—, and —. CH ₂ CH ₂ OCO−, − (CH ₂ O) _n2
— (N ₂ represents an integer of 1 or 2), —CH ₂ CH ₂ O— and the like, and represents a connecting group having 1 to 4 connecting atoms.

Z ₂ in the formula (V b) represents the same content as Z _1.

Specific examples of the copolymer component corresponding to the repeating unit represented by the formula (Va) or (Vb) are shown below, but the scope of the present invention is not limited thereto.

In each of the following examples, T ₁ and T ₂ each represent a hydrogen atom, Cl, Br or I, and R ₅₁ is C _a H _{2a + 1} or A represents an integer of 1 to 4, b represents an integer of 0 or 1 to 3, and c represents an integer of 1 to 3.

Then, the acidic functional group in the present invention, -PO ₃ H ₂
Group, -SO ₃ H group, -COOH group, -P (R) O ₂ H groups, phenolic OH groups, and cyclic acid anhydride-containing group.
More preferably -PO ₃ H ₂ group, -SO ₃ H group, -COOH group, and cyclic acid anhydride-containing group.

In the —P (R) O ₂ H group, R represents a hydrocarbon group or O
R ′ represents a group (R ′ represents a hydrocarbon group), and R and R ′ are preferably an aliphatic group having 1 to 7 carbon atoms (eg, methyl, ethyl, propyl, butyl, hexyl, 2-chloroethyl, 2-chloroethyl). Methoxyethyl, 3-ethoxypropyl,
Allyl, crotonyl, butenyl, benzyl, chlorobenzyl, fluorobenzyl, methoxybenzyl and the like, or an optionally substituted aryl group (for example, phenyl, tolyl,
Ethylphenyl, propylphenyl, chlorophenyl,
Fluorophenyl, bromophenyl, chloro-methyl-phenyl, dichlorophenyl, methoxyphenyl, cyanophenyl, acetamidophenyl, acetylphenyl,
Butoxyphenyl etc.).

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

Examples of the aliphatic dicarboxylic anhydride include a succinic anhydride ring, a glutaconic anhydride ring, a maleic anhydride ring,
Cyclopentane-1,2-dicarboxylic anhydride ring, cyclohexane-1,2-dicarboxylic anhydride ring, cyclohexene-1,2-dicarboxylic anhydride ring, 2,3-bicyclo [2,2,
2] Octanedicarboxylic anhydride rings and the like, which may be substituted with halogen atoms such as chlorine and bromine, and alkyl groups such as methyl, ethyl, butyl and hexyl.

Examples of the aromatic dicarboxylic anhydride include a phthalic anhydride ring, a naphthalene-dicarboxylic anhydride ring, a pyridine-dicarboxylic anhydride ring, a thiophene-dicarboxylic anhydride ring, and the like. Is, for example, chlorine,
Substituted with a halogen atom such as bromine or an alkyl group such as methyl, ethyl, propyl or butyl, and further substituted with a hydroxyl group, a cyano group, a nitro group or an alkoxycarbonyl group (alkoxy groups such as methoxy and ethoxy). You may.

The "monofunctional group monomer containing an acidic group" of the present invention includes, for example, an acidic monomer copolymerizable with a monomer corresponding to the polymer component represented by the above general formula (I), (II) or (III). Any compound may be used as long as it is a vinyl compound containing a group. For example, it is described in “Polymer Data Handbook [Basic Edition] Baifukan (1986)” edited by The Society of Polymer Science, Japan.

Specifically, acrylic acid, α- and / or β-substituted acrylic acid (for example, α-acetoxy, α-acetoxymethyl, α- (2-amino) methyl, α-chloro, α-
Bromo form, α-fluoro form, α-tributylsilyl form, α
-Cyano form, β-chloro form, β-bromo form, α-chloro-β-methoxy form, α, β-dichloro form, etc.), methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid half amides, Crotonic acid, 2-alkenylcarboxylic acids (eg, 2-pentenoic acid, 2-methyl-2-hexenoic acid, 2-octenoic acid, 4-methyl-2-hexenoic acid,
-Ethyl-2-octenoic acid, etc.), maleic acid, maleic acid half esters, maleic acid half amides, vinylbenzene carboxylic acid, vinylbenzenesulfonic acid, vinylsulfonic acid, vinylphosphonic acid, vinyl group or allyl of dicarboxylic acids Half ester derivatives of these groups; ester derivatives of these carboxylic acids or sulfonic acids; and compounds containing the acidic group in the substituents of the amide derivatives.

Hereinafter, the "functional monomer containing an acidic group-functional monomer" will be exemplified, but the scope of the present invention is not limited thereto.

Further, the binding resin [A] may contain, as a copolymerization component, other monomers that can be copolymerized with the macromonomer (MA), the monomer (A) and the monomer (B).

For example, α-olefins, N-substituted acrylamides, N-substituted methacrylamides (where the N-substituent is a hydrocarbon group, specifically, a hydrocarbon group represented by Q ₀ in the general formula (III) And heterocyclic vinyls (e.g., vinylpyrrolidone, pinylpyridine, vinylimidazole, vinylthiophene, vinylimidazoline, vinylpyrazole, vinyldioxane, vinylquinoline, vinylthiazole, vinyloxazine, etc.). 20% by weight of these other monomers in the copolymer
It is preferable not to exceed the above.

Furthermore, the binding resin [A] of the present invention has only one terminal of a polymer main chain containing at least one repeating unit represented by the general formula (III) and at least one repeating unit represented by a macromonomer. -PO ₃ H ₂ group, -SO ₃ H groups, -C
OOH group, an -OH group, a polymer formed by combining at least one acidic group selected from -PO ₃ RH group and a cyclic acid anhydride-containing group (binding resin [A ']).

Here, the acidic group has a chemical structure in which it is directly bonded to one end of the polymer main chain or is bonded via an arbitrary linking group.

Examples of the bonding group include a carbon-carbon bond (single bond or double bond), a carbon-heteroatom bond (for example, an oxygen atom, a sulfur atom, a nitrogen atom, and a silicon atom), and a heteroatom-heteroatom bond. It is composed of any combination of atomic groups. For example, a single linking group selected from the same atomic groups as G represented by the general formulas (IVa) and (IVb), or a linking group formed by an arbitrary combination, and the like can be mentioned.

Further above The cyclic acid anhydride-containing group has the same contents as described in the monomer (B).

In the binding resin [A '], as a method of binding the acidic group to one terminal of the polymer main chain, a method of reacting various reagents at the terminal of a living polymer obtained by conventionally known anionic or cationic polymerization ( Ion polymerization method), a method of radical polymerization using a polymerization initiator and / or a chain transfer agent containing a specific acidic group in the molecule (method by radical polymerization method), or an ion polymerization method or radical as described above A reactive group (for example, an amino group, a halogen atom,
It can be easily produced by a synthesis method such as a method of converting a polymer containing an epoxy group or an acid halide group) into a specific polar group of the present invention by a polymer reaction.

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

Specifically, as the chain transfer agent to be used, for example, a mercapto compound containing the acidic group or the above-mentioned reactive group (a group which can be derived into the acidic group later) (for example, thioglycolic acid, thiomalic acid, thiosalicylic acid, -Mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, N- (2-mercaptopropionyl) glycine, 2-mercaptonicotinic acid, 3- [N- (2-mercaptoethyl) carbamoyl] propionic acid, 3-
[N- (2-mercaptoethyl) amino] propionic acid, N- (3-mercaptopropionionyl) alanine,
2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid, 4-mercaptobutanesulfonic acid, 2
-Mercaptoethanol, 3-mercapto-1,2-propanediol, 1-mercapto-2-propanol, 3
-Mercapto-2-butanol, mercaptophenol, 2-mercaptoethylamine, 2-mercaptoimidazole, 2-mercapto-3-pyridinol, 4-
(2-mercaptoethyloxycarbonyl) phthalic anhydride, 2-mercaptoethylphosphonoic acid, monomethyl 2-mercaptoethylphosphonoate, or an iodinated alkyl compound containing the above acidic group or substituent (for example, iodine Acetic acid, iodopropionic acid, 2-iodoethanol, 2-iodoethanesulfonic acid, 3-iodopropanesulfonic acid, etc.), and preferably a mercapto compound.

Specific examples of the polymerization initiator containing the acidic group or the specific reactive group include 4,4′-azobis (4-cyanovaleric acid) and 4,4′-azobis (4-cyanovaleric acid). Chloride), 2,2'-azobis (2-cyanopropanol), 2,2'-azobis (2-cyanopentanol),
2,2'-azobis [2-methyl-N- (2-hydroxyethyl) -propioamide], 2,2'-azobis {2-
Methyl-N- [1,1-bis (hydroxymethyl) -2-
Hydroethyl] propioamide {2,2'-azobis} 2
-[1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane}, 2,2'-azobis [2- (2
-Imidazolin-2-yl) propane] and 2,2'-azobis [2-4,5,6,7-tetrahydro-1H-1,3-diazopin-2-yl) propane].

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

As the photoconductive compound used in the present invention,
Any of conventionally known organic photoconductors may be used. Specifically, the following two types of electrophotographic printing plate precursors are known as conventionally known examples. The first is Japanese Patent Publication No. 37-17162,
JP-A-62-51462, JP-A-52-2437, JP-A-54-19803,
Nos. 56-107246 and 57-161863, each having a photoconductive layer mainly composed of an organic photoconductive compound, a sensitizing dye, and a binding resin. , 60
-17751, 60-17752, 60-17760, 60-254
No. 142 and No. 62-54266, which have a photoconductive layer mainly composed of a charge generating agent, a charge transporting agent, and a binding resin.

As a special case of the second example, JP-A-60-230147,
As described in JP-A-60-230148 and JP-A-60-238853, a two-layered photoconductive layer containing a charge generating agent and a charge transporting agent in separate layers is also known. The printing plate precursor for electrophotographic plate making of the present invention may take any of the above two types of photoconductive layers. In the case of the second example, the organic photoconductive compound according to the present invention functions as a charge transport agent.

Examples of the organic photoconductive compound in the present invention include (a) a triazole derivative described in U.S. Pat. No. 3,112,197, (b) an oxadiazole derivative described in U.S. Pat. No. 3,189,447, and (c) JP-B-37-16096. (D) U.S. Pat. Nos. 3,615,402, 3,820,989, and 3,54.
No. 2,544, JP-B-45-555, JP-B-51-10,983, JP-A-51
-93,224, 55-108,667, 55-156953, 56
(E) U.S. Pat. Nos. 3,180,729 and 4,278,746;
55-88,064, 55-88,065, 49-105,537, 5
5-51,086, 56-80,051, 56-88,141, 57
Pyrazoline derivatives and pyrazolone derivatives described in JP-A-45,545, JP-A-54-112,637 and JP-A-55-74,546; (f) U.S. Pat. No. 3,615,404, JP-B-51-10,105,
Nos. 46-3,712 and 47-28,336, JP-A-54-83,435
Phenylenediamine derivatives described in JP-A Nos. 54-110,836 and 54-119,925; (g) U.S. Patent Nos. 3,567,450, 3,180,703, and 3,24
0,597, 3,658,520, 4,232,103, 4,175,961
No. 4,012,376, West German Patent (DAS) 1,110,518,
JP-B-49-35,702, JP-B-39-27,577, JP-A-55-144,
Nos. 250, 56-119,132 and 56-22,437, (h) amino-substituted alcon derivatives described in U.S. Pat. No. 3,526,501, (i) N described in U.S. Pat. No. 3,542,546 , N-bicalpadil derivatives, (j) oxazole derivatives described in U.S. Pat. No. 3,257,203, (k) styryl anthracene derivatives described in JP-A-56-46,234, (l) JP-A-54-110,837 (M) U.S. Pat. No. 3,717,462, JP-A-54-59,143 (corresponding to U.S. Pat. No. 4,150,987), and 55-52,063;
No. 55-52,064, No. 55-46,760, No. 55-85,495, No.
Hydrazone derivatives described in Nos. 57-11,350, 57-148,749 and 57-104,144; (n) U.S. Patent Nos. 4,047,948, 4,047,949, and 4,26
5,990, 4,273,846, 4,299,897, 4,306,008
(O) JP-A-58-190,953, JP-A-59-95,540 and JP-A-59-9
Nos. 7,148, 59-195, 658 and 62-36,674, (p) Polybitylcarbazole and its derivatives described in JP-B-34-10,966, (q) JP-B 43-18,674 No. 43-19,192, polyvinyl pyrene, polybityl anthracene, poly-2
-Vinyl-4- (4'-dimethylaminophenyl) -5
Vinyl polymers such as -phenyloxazole and poly-3-vinyl-N-ethylcarbazole; and (s) polymers such as polyacenaphthylene, polyindene and copolymers of acenaphthylene and styrene described in JP-B-43-19,193. (T) Condensed resins such as pyrene-formaldehyde resin, bromopyrene-formaldehyde resin and ethylcarbazole-formaldehyde resin described in JP-B-56-13,940, and (u) JP-A-56-90,883 and 56-161,550. There are various triphenylmethane polymers described in the gazette.

In the present invention, the organic photoconductive compound comprises (a)
The compounds are not limited to the compounds described in (a) to (u), and all known organic photoconductive compounds can be used.
These organic photoconductive compounds may be used in combination of two or more in some cases.

As the sensitizing dye contained in the photoconductive layer of the first example,
Conventionally known sensitizing dyes used for electrophotographic photoreceptors can be used. These are "electrophotography" 12 9, (1973),
“Synthetic Organic Chemistry” 24 (11), 1010, (1966). For example, U.S. Pat.Nos. 3,141,770 and 4,283,475
Nos, JP-B-48-25658, pyrylium dyes described in JP-A-62-71965, etc., Applied Optics Supplement 3 50
(1969), triarylmethane dyes described in JP-A-50-39548, cyanine dyes described in U.S. Pat. No. 3,597,196, JP-A-60-163047, JP-A-59-164588, JP
Styryl dyes described in JP-A-60-252517 and the like are advantageously used.

As the charge generator contained in the photoconductive layer of the second example, various organic and inorganic charge generators conventionally known in an electrophotographic photoreceptor can be used. For example, selenium, selenium-tellurium, cadmium sulfide, zinc oxide, and organic pigments shown in the following (1) to (9) can be used.

(1) U.S. Pat. Nos. 4,436,800 and 4,439,506;
No. 47-37543, No. 58-123,541, No. 58-192,042, No. 5
8-219,263, 59-78,356, 60-179,746, 6
Nos. 1-148,453, 61-238,063, JP-B-60-55941,
Azo pigments such as monoazo, bisazo and trisazo pigments described in JP-A-60-45,664; (2) U.S. Pat. Nos. 3,397,086 and 4,666,802;
51-90827, 52-55643 and the like, metal-free or metal phthalocyanine and the like, and phthalocyanine pigments; (3) U.S. Pat. No. 3,371,884, berylen-based pigments described in JP-A-47-30330, etc. ) Indigo and thioindigo derivatives described in British Patent No. 2,237,680, JP-A-47-30331, etc .; (5) Quinacridone pigments described in British Patent No. 2,237,679, JP-A-49-30332, etc .; UK Patent No. 2,237,678, JP-A-59-184,348,
Polycyclic quinone pigments described in JP-A-62-28,738 and JP-A-47-18544, (7) bisbenzimidazole pigments described in JP-A-47-30331, JP-A-47-18543, etc. 8) Squarium salt-based pigments described in U.S. Pat. Nos. 4,396,610 and 4,644,082, and (9) Azurenium salt-based pigments described in JP-A-59-53,850 and JP-A-61-212,542. These can be used alone or in combination of two or more.

The upper limit of the content ratio of the organic photoconductive compound is determined by the compatibility between the organic photoconductive compound and the binding resin. Crystallization of the conductive compound occurs, which is not preferable. Since the lower the content of the organic photoconductive compound, the lower the electrophotographic sensitivity, it is preferable to include as much organic photoconductive compound as possible within a range where crystallization of the organic photoconductive compound does not occur. The content of the organic photoconductive compound is 5 to 120 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the binder resin. The organic photoconductive compounds may be used alone or as a mixture of two or more.

The photoconductive layer of the electrophotographic printing plate precursor of the present invention,
Various known additives conventionally used in electrophotographic photoreceptors can be incorporated. These additives include a chemical sensitizer for improving electrophotographic sensitivity, various plasticizers for improving film properties, and a surfactant. Examples of the chemical sensitizer include P-benzoquinone,
Chloranil, fluoranil, bromanyl, dinitrobenzene, anthraquinone, 2,5-dichlorobenzoquinone,
Nitrophenol, tetrachlorophthalic anhydride, 2,3-
Electron-withdrawing compounds such as dichloro-5,6-dicyanobenzoquinone, dinitrofluorenone, trinitrofluorenone, and tetracyanoethylene; JP-A-58-65439;
And the compounds described in JP-A-102239, JP-A-58-129439, JP-A-62-71965 and the like.

Examples of the plasticizer include dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, triphenyl phosphate, diisobutyl adipate, dimethyl sebacate, dibutyl sebacate, butyl laurate, methyl phthalyl ethyl glycolate, and dimethyl glycol phthalate. Can be added in order to improve the flexibility. These plasticizers can be contained within a range that does not deteriorate the electrostatic properties and etching properties of the photoconductive layer.

Further, if the thickness of the photoconductive layer of the present invention is too small, the surface potential required for development cannot be charged. Conversely, if the thickness is too large, a planar direction called side etch when removing the photoconductive layer is used. And a good printing plate cannot be obtained. The thickness of the photoconductive layer is 0.1 μm to 30 μm, preferably 0.5 μm to 10 μm.

Examples of the conductive support used in the present invention include a plastic sheet having a conductive surface or a paper made especially solvent-impermeable and conductive, an aluminum plate, a zinc plate, or a copper-aluminum plate, a copper-stainless plate, and chromium. -A conductive support having a hydrophilic surface such as a bimetal plate such as a copper plate, or a trimetal plate such as a chromium-copper-aluminum plate, a chromium-lead-iron plate, or a chromium-copper-stainless plate is used. Is preferably 0.1 mm to 3 mm, and particularly preferably 0.1 mm to 3 mm.
1 mm to 0.5 mm is preferred. Among these supports, an aluminum plate is preferably used. The aluminum plate used in the present invention is a plate-like body such as pure aluminum containing aluminum as a main component or an aluminum alloy containing a trace amount of a heteroatom. Can be used as appropriate.

This aluminum plate can be used by graining and anodizing by a conventionally known method. Prior to the graining treatment, a degreasing treatment with a surfactant or an alkaline aqueous solution is performed, if desired, to remove the rolling grease on the surface of the aluminum plate, and the graining treatment is performed. The graining method includes a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of chemically selectively dissolving the surface.

As a method for mechanically roughening the surface, a known method called a pole polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used.

In addition, as an electrochemical surface roughening method, there is a method in which an alternating current or a direct current is used in a hydrochloric acid or nitric acid electrolyte.

Further, a method combining both of them can be used as disclosed in JP-A-54-63902. The aluminum plate thus roughened is subjected to an alkali etching treatment and a neutralization treatment as necessary.

Next, this aluminum plate is anodized. As the electrolyte used for the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used, and the electrolyte and the concentration thereof are appropriately determined depending on the type of the electrolyte. Since the anodizing treatment conditions vary depending on the electrolyte used, they cannot be specified unconditionally, but in general, the concentration of the electrolyte is 1% by weight to 80% by weight, and the solution temperature is 5 ° C to 70 ° C.
Current density ^{5A / cm 2 ~60A / cm 2} , voltage 1V～100V, electrolysis time 10
It is preferable to have a range of seconds to 50 minutes. Anodized film amount is 0.1g / m ² ~10g / m ² are preferred, more preferably from 1 to 6 g / m ^2.

Further, as described in JP-B-47-5125, an aluminum plate which is anodized and then immersed in an aqueous solution of an alkali metal silicate is preferably used. Further, silicate electrodeposition as described in US Pat. No. 3,866,662 is also effective. The treatment with polyvinyl sulfonic acid described in West German Patent Application No. 1621478 is also suitable.

Further, in the present invention, between the conductive support and the photoconductive layer, if necessary for the purpose of improving the adhesion and the electrostatic properties of the electrophotographic printing plate precursor, for example casein, polyvinyl alcohol, ethylcellulose And an alkali-soluble intermediate layer made of phenol resin, styrene, maleic anhydride copolymer, polyacrylic acid, or the like.

Further, in the present invention, if necessary on the photoconductive layer, electrostatic characteristics, development characteristics during toner development, or image characteristics,
For the purpose of improving printing characteristics and the like, an overcoat layer that can be removed simultaneously with the removal of the photoconductive layer can be provided. This overcoat layer may be a mechanically matted one or a resin layer containing a matting agent. In this case, as a matting agent, silicon dioxide, glass particles, alumina, starch, titanium oxide, zinc oxide,
Polymethyl methacrylate, polystyrene, particles of polymers such as phenolic resins and U.S. Pat.No. 2,701,245,
The matting agents described in the specification of JP 2992101 are included. These can be used in combination of two or more.

The resin used for the overcoat layer is appropriately selected depending on the combination with the etching solution for removing the photoconductive layer. Specifically, for example, gum arabic, glue,
Examples include celluloses, starches, polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinyl methyl ether, epoxy resins, phenol resins, polyamides, and polyvinyl butyral. These can be used in combination of two or more.

The toner used in the present invention has a resistance to an etching solution for removing a non-image portion, has a function of preventing the photoconductive layer of the toner image portion from being eluted from the etching solution, and includes a dry developer and a liquid developer. Any of these can be used as long as it is used as a toner for electrophotography, but it is preferable to use a liquid developer in order to obtain a high-resolution image.

Further, those which provide a hydrophobic and ink-receptive toner image are desirable. For example, the components of the toner particles include polystyrene resins, polyester resins, homopolymers and copolymers of acrylic esters, homopolymers and copolymers of methacrylic esters, ethylene copolymers, cyclized rubbers, and homopolymers of vinyl acetate. Polymer materials such as copolymers and vinyl chloride are used.

Further, a coloring agent such as carbon black, a nigrosine-based pigment, phthalocyanine blue, phthalocyanine green, benzidine yellow, alkali blue, carmine 6B and the like within a range that does not adversely affect the fixability, dispersibility and etching resistance of the toner. It can also contain pigments and dyes. Furthermore, various charge control agents and other additives may be contained.

As an etching solution for removing the photoconductive insulating layer of the toner non-image portion after toner image formation, any solvent can be used as long as the photoconductive insulating layer can be removed, but is not particularly limited, Preferably, an alkaline solvent is used.

The alkaline solvent referred to here is a water-soluble or alkaline compound-containing organic solvent, or a mixture of an aqueous solution containing an alkaline compound and an organic solvent. Alkaline compounds include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate, potassium phosphate, ammonia, and monoethanolamine, diethanolamine, triethanolamine. Examples thereof include any organic and inorganic alkaline compounds such as amine alcohols such as ethanolamine. As described above, water or many organic solvents can be used as a solvent for the etching solution, but an etching solution mainly containing water is preferably used from the viewpoint of odor and pollution. Various organic solvents can be added to the etching solution mainly composed of water, if necessary.

Preferred organic solvents include methanol, ethanol, propanol, butanol, benzyl alcohol,
Examples thereof include lower alcohols such as phenethyl alcohol, aromatic alcohols, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, cellosolves, and amino alcohols such as monoethanolamine, diethanolamine, and triethanolamine. Further, a solution containing a surfactant, an antifoaming agent, and other various additives as necessary is used as the etching solution.

Next, a method of preparing a printing plate from the printing plate precursor for electrophotographic plate making of the present invention will be described. The printing plate precursor for electrophotographic plate making of the present invention is formed with an image by a conventionally known electrophotographic process.

That is, it is charged substantially uniformly in a dark place, and forms an electrostatic latent image by image exposure. Examples of the exposure method include a reflection image exposure using a xenon lamp, a tungsten lamp, and a fluorescent lamp as a light source, a contact exposure through a transparent positive film, and a scanning exposure using a laser beam, a light emitting diode, or the like.

When performing scanning exposure, helium-neon laser,
Helium-cadmium laser, argon ion laser, krypton ion laser, YAG laser, ruby laser, nitrogen laser, dye laser, excimer laser, semiconductor laser such as GaAs / GaAlAs, InGaAsP, alexandrite laser, copper vapor laser, erbium laser, etc. Scanning exposure with a laser light source,
Alternatively, exposure can be performed by scanning exposure using a light emitting diode or a liquid crystal shutter (including a line printer type light source using a light emitting diode array, a liquid crystal shutter array, or the like).

Next, as a developing method for developing the electrostatic latent image with toner, any of a dry developing method (cascade developing, a magnetic brush developing, a powder cloud developing) and a liquid developing method can be used. Among them, the liquid development method can form a fine image and is suitable for preparing a printing plate. Further, positive-bodied development by positive development and negative-positive development by reversal development by applying an appropriate bias voltage are also possible. The printing plate can be prepared by fixing the formed toner image, using the formed toner image as a resist, and removing the photoconductive layer in the non-image area with an etchant.

[Action]

In a method of forming a printing plate by forming an image by an electrophotographic method and then performing an etching treatment (that is, removing a non-image portion), a conventionally known photosensitive resin comprising a known binding resin and an organic photoconductive compound is used. In the body, electrophotographic properties,
There were various problems in the suitability for etching (that is, the non-image area is easily removed) and the printing durability.

That is, evenly dispersing the photoconductive compound with the binder resin depends on the hydrophilic group-containing component in the binder resin, but when the hydrophilic group-containing component is increased to improve etching suitability, the dispersibility is impaired. Even if a photoreceptor is formed, electrophotographic characteristics (eg, initial potential, light sensitivity,
Characteristics that are satisfactory in dark decay and the like cannot be obtained.

Conversely, when the amount of the hydrophilic group component is reduced, the removal of the non-image portion by the etching treatment becomes insufficient due to insufficient water solubility of the binder resin even though the electrophotographic characteristics can be satisfied. Will occur.

In addition, binder resins having good suitability for alkali etching treatment (eg, maleic anhydride copolymer, aliphatic carboxylic acid vinyl ester-crotonic acid copolymer, etc.) have unsatisfactory electrophotographic properties, and particularly require the use of a laser light source. In the conventional scanning exposure method, the image quality of a copied image deteriorates. Further, the printing durability is insufficient and high printing durability cannot be obtained.

The binding resin of the present invention can solve these contradictory problems.

That is, a lithographic printing plate precursor having remarkably good electrophotographic properties even by the scanning exposure method and further satisfying the suitability for etching treatment and high printing durability can be obtained.

The binding resin of the present invention is a graft type block copolymer comprising a specific monomer (A) represented by the formula (III), an acidic group-containing monomer (B) and a monofunctional macromonomer (MA), Is characterized in that an acidic group is bonded to one end of the main chain of the polymer, and preferably, the graft copolymer has a Mw of 3 × 10 ³ to 2 × 10 ⁴ .

By specifying the structure of the repeating component of the polymer, and by having a graft portion having a specific structure, the electrophotographic properties have been improved. Dispersion is sufficiently performed. Further, it is considered that the suitability of the non-image area for etching treatment and the printing durability of the image area are improved because of the graft type block copolymer. Since these are polymers having a graft structure, it is considered that the above-described effects are exerted in the photoconductive layer by the interaction between the microphase-separated structure and the molecular chains of the polymer chains.

Hereinafter, production examples of the macromonomer MA and the binding resin [A] in the present invention will be described.

Production Example 1 of Macromonomer MA: MA-1 A mixed solution of 95 g of methyl methacrylate, 5 g of thioglycolic acid and 200 g of toluene was stirred under a nitrogen stream,
Heated to a temperature of 70 ° C. 1.0 g of 2,2'-azobis (isobutyronitrile) (AIBN) was added and reacted for 8 hours. Next, 8 g of glycidyl methacrylate and N, N-
1.0 g of dimethyldodecylamine and 0.5 g of t-butylhydroquinone were added, and the mixture was stirred at a temperature of 100 ° C. for 12 hours. After cooling, the reaction solution was reprecipitated in methanol 2 to obtain 82 g of a white powder. The weight average molecular weight (abbreviated Mw) of the polymer is 5.8
00.

Production Example 2 of Macromonomer MA: MA-2 A mixed solution of 95 g of 2-chlorophenyl methacrylate, 5 g of β-mercaptopropionic acid and 200 g of toluene was heated to a temperature of 70 ° C. while stirring under a nitrogen stream. AIBN
1.5 g was added and reacted for 8 hours. Next, 7.5 g of glycidyl methacrylate, 1.0 g of N, N-dimethyldodecylamine and 0.8 g of t-butylhydroquinone were added to the reaction solution, and the mixture was stirred at a temperature of 100 ° C. for 12 hours. After cooling, the reaction solution was reprecipitated in methanol 2 to obtain 85 g of a colorless and transparent viscous substance. The weight average molecular weight of the polymer was 3,500.

Production Example 3 of Macromonomer MA: MA-3 A mixed solution of 94 g of butyl methacrylate, 6 g of 2-mercaptoethanol and 200 g of toluene was heated to a temperature of 70 ° C. under a nitrogen stream. 1.2 g of AIBN was added and reacted for 8 hours.

Next, the reaction solution was cooled in a water bath to a temperature of 20 ° C.,
Triethylamine (10.2 g) was added, and methacrylic acid chloride (14.5 g) was added dropwise with stirring at a temperature of 25 ° C. or lower. After the addition, the mixture was further stirred for 1 hour. Thereafter, 0.5 g of t-butylhydroquinone was added, the mixture was heated to a temperature of 60 ° C, and stirred for 4 hours. After cooling, the precipitate was reprecipitated in methanol 2 to obtain 79 g of a colorless and transparent viscous substance. The weight average molecular weight was 6,000.

Production Example 4 of Macromonomer MA: MA-4 95 g of ethyl methacrylate and 200 of tetrahydrofuran
g of the mixed solution was heated to 70 ° C. under a nitrogen stream. 2,2 ′
-Azobis (cyanoheptanol) (5 g) was added and reacted for 8 hours.

After cooling, the reaction solution was brought to a temperature of 20 ° C. in a water bath, 1.0 g of triethylamine and 21 g of methacrylic anhydride were added, and the mixture was stirred for 1 hour and then at a temperature of 60 ° C. for 6 hours.

The obtained reaction product was cooled and then reprecipitated in ethanol 2 to obtain 79 g of a colorless and transparent viscous substance. Weight average molecular weight is 8.5
00.

Production Example 5 of Macromonomer MA: MA-5 A mixed solution of 96 g of benzyl methacrylate, 4 g of thioglycolic acid and 200 g of toluene was heated to a temperature of 75 ° C. while stirring under a nitrogen stream. 1.5 g of AIBN was added and reacted for 8 hours. Next, the reaction mixture was cooled to a temperature of 25 ° C., to which 10 g of 2-hydroxyethyl methacrylate and 1.5 g of t-butylhydroquinone were added and stirred. A mixed solution of 25 g of dicyclohexylcarbodiimide (abbreviation: DCC), 1 g of 4- (N, N-dimethylamino) pyridine and 100 ml of methylene chloride was added dropwise with stirring for 1 hour. After completion of the dropwise addition, the mixture was further stirred for 4 hours, and then 10 g of acetic acid was added, followed by stirring for 1 hour.
The precipitated crystals were separated by suction filtration and then reprecipitated in methanol 2. The precipitate was collected by decantation, dissolved in 200 ml of methylene chloride, and re-precipitated in methanol 1 again.

The precipitate was collected by decantation and dried under reduced pressure. The yield of the obtained liquid was 58 g, and Mw was 7.3 × 10 ³ .

Production Example 1 of Binding Resin [A] 1: [A-1] 60 g of benzyl methacrylate, macromonomer (MA-
1) A mixed solution of 20 g, 20 g of methacrylic acid and 150 g of toluene was heated to a temperature of 80 ° C. while stirring under a nitrogen stream. 2,2 ′
-Azobis (isovalero tolyl) (abbreviation: ABVN) 6
g, and reacted for 4 hours. Then, 0.5 g of ABVN was added, followed by 3 hours, and further 0.3 g of ABVN was added, followed by reaction for 3 hours.

The Mw of the obtained copolymer was 8.8 × 10 ³ .

Production Example 2: Binder resin [A]: [A-2] Ethyl methacrylate 57 g, macromonomer (MA-
2) A mixed solution of 25 g, 18 g of acrylic acid, 100 g of toluene and 50 g of isopropanol was heated to a temperature of 80 ° C. under a nitrogen stream. 4,4'-azobis (4-cyanovaleric acid) (abbreviation: AC
V.) 5.0 g was added and reacted for 6 hours.
Reacted for hours. The Mw of the obtained copolymer was 9.0 × 10 ³ .

Production Example 3 of binding resin [A]: [A-3] benzyl methacrylate 60 g, macromonomer (MA-
4) A mixed solution of 20 g, itaconic acid 20 g, thiosalicylic acid 3 g and toluene 200 g was heated to a temperature of 70 ° C. under a nitrogen stream. A.
1.0 g of IBN was added and reacted for 4 hours, and 0.8 g of AIBN was further added and reacted for 4 hours.

Mw of the obtained polymer was 9.3 × 10 ³ .

Production Example 4 of Binder Resin [A]: [A-4] A mixed solution of 65 g of 2-methylphenyl methacrylate, 15 g of macromonomer (MA-5), 20 g of methacrylic acid 1 g of n-butyl mercaptan 1 g and 200 g of toluene was heated under a nitrogen stream.
Heated to 70 ° C. Add 1g of AIBN and react for 5 hours.
0.6 g of AIBN was added and reacted for 4 hours.

After cooling, the reaction solution was reprecipitated in 1.5 of n-hexane, and the powder was collected and dried. 85 g of white powder, Mw 7.8
× was 10 ^3.

Examples of the present invention will be described below, but the contents of the present invention are not limited to these.

(Example 1) The following trisazo compound as a charge generating agent: 1.0 part Hydrazone compounds shown below as organic photoconductive compounds: 2.0 parts Binding resin: [A-1] 10.0 parts (as solid content) Tetrahydrofuran 100 parts were put together with glass beads in a 500 ml glass container, and dispersed for 60 minutes with a paint shaker (Toyo Seiki Seisakusho KK). The glass beads were separated by filtration to obtain a dispersion for a photoconductive layer.

Next, this photoconductive layer dispersion was grained to a thickness of 0.25.
Apply and dry on an aluminum plate with a thickness of 5.1μ
An electrophotographic printing plate precursor having m photoconductive layers was prepared.

Next, an electrophotographic photoreceptor as a comparative example described below was prepared in the same manner as in Example 1 except that the following resin was used in place of the copolymer [A-1].

[Comparative Example A]

[Copolymer A] Styrene-maleic anhydride copolymer (maleic anhydride content: 33 mol%) [Comparative Example B] [Copolymer B] vinyl acetate-crotonic acid copolymer (manufactured by Kanebo NSC: Resyn-28-1310) [Comparative Example C] [Copolymer C] Benzyl methacrylate-methacrylic acid (75/25 weight ratio) MW 8 × 10 ³
Printing was carried out in a conventional manner using a D offset printing machine, and printability (printing durability and the like) was examined.

 The above results are summarized in the following table.

Embodiments of the evaluation items shown in the above table are as follows.

Note 1) Electrostatic characteristics: In a dark room at a temperature of 20 ° C, 65% RH and (30 ° C, 80% RH)
Use a paper analyzer (Kawaguchi Electric Co., Ltd. product paper analyzer SP: 428) for each photosensitive material at +7 kV for 20
After the second corona discharge, and left for 10 seconds to measure the surface potential V ₁₀ at this time. Next, the potential V ₁₉₀ after standing for 180 seconds in the dark was measured, and the potential retention after attenuating for 180 seconds, that is, the dark decay retention [DRR (%)],
Obtained by _{(V 190 / V 10) ×} 100 (%).

After charging the surface of the photoconductive layer to +400 V by corona discharge, the surface of the photoconductive layer is irradiated with monochromatic light having a wavelength of 633 nm, and the time until the surface potential (V ₁₀ ) attenuates to half is determined. From this, the exposure amount B _1/2 (erg / cm ² ) is calculated.

Further, similarly determine the time until the V ₁₀ is attenuated to 1/10,
From this, the exposure amount B _1/10 (erg / cm ² ) is calculated.

Note 2) Imaging properties: Each photosensitive material was left for one day and night under the following environmental conditions. Regarding the electrostatic characteristics of these photosensitive materials, environmental conditions (20 ° C,
65% RH) and (30 ° C., 80% RH).

Further, after these photosensitive materials are charged to a surface potential of +450 V in a dark place, they are exposed to light of 633 nm using a He-Ne laser so that the exposure amount on the plate surface becomes 30 erg / cm ^2. Using a liquid developer prepared by dispersing 5 g of polymethyl methacrylate particles (particle size: 0.3 μm) as toner particles in Isopar H (Esso Standard) 1 and adding 0.01 g of soybean oil lecithin as a charge control agent, A toner image was obtained by applying a bias voltage of 30 V to the counter electrode and developing. The toner image was further fixed by heating at 100 ° C. for 1 minute.

The reproducibility (fog, image quality of the image) of the copy image of the original plate after the plate making thus obtained on the original image was visually evaluated.

Note 3) Etching processability: 40 parts of potassium silicate, 10 parts of potassium hydroxide, 100 parts of ethanol and 8 parts of water
It was removed by immersion in an etching solution diluted to 00 parts for 20 seconds, washed with water for 30 seconds, and air-dried with a dryer.

The extent of the film remaining in the non-image area of the printing plate and the presence or absence of thin lines and fine characters in the image area were measured using a 60x loupe (PE
(AK Co., Ltd.).

Note 3) Printing durability: Each photosensitive material is made into a plate under the same conditions as in Note 2) to form a toner image, etched under the same conditions as in Note 3), and gummed to offset. Printing original plate was created.

These are printed on an offset printing machine (Oliver 52, Sakurai Seisakusho Co., Ltd.) to indicate the number of sheets that can be printed without causing background contamination in the non-image area of the printed matter and the image quality of the image area. Good performance).

In the electrostatic characteristics, Comparative Example C was good, but the light sensitivity (E _1/2 , E _1/10 ) was lower than that of the present invention. E) was insufficient, and its value further deteriorated when environmental conditions changed.

Actually examining the image-capturing properties of these photoconductors, those of the present invention correspond to the above-mentioned electrostatic characteristics and show a good copied image even when the environment changes.

Next, all of the present invention and Comparative Examples A, B, and C, which were subjected to an etching treatment to form a printing plate, were sufficiently eluted, and no residual film was observed.

Further, when printing was performed as an offset master, only the image of the present invention had a clear image with no background smear even after printing 100,000 sheets. In Comparative Example C, the image quality of printed matter was degraded (loss of fine lines, characters, etc.) on 60,000 sheets.

In Comparative Examples A and B, the elution of the non-image area was sufficient, and no background stain was observed, but the image quality of the copied image was unsatisfactory.
The lack of an image portion of the obtained printed matter was caused by printing.

As described above, only the printing original plate of the present invention satisfied the electrophotographic characteristics and the printing characteristics.

(Examples 2 to 4) In the same manner as in Example 1, except that the copolymer shown in the following table was used instead of the polymer [A-1], printing for electrophotographic plate making was performed. The original version was created.

In the same manner as in Example 1, the electrostatic characteristics, imaging properties, and printability were examined. The above table shows the electrostatic characteristics under severe conditions (30 ° C., 80% RH). Each of the photoreceptors showed good results as in Example 1. In addition, imaging performance and printability (10
(Million sheets) showed the same result as the photoreceptor of Example 1.

(Example 5) A lithographic printing plate precursor was prepared in the same manner as in Example 1 except that the following oxadiazole compound was used instead of the hydrazone compound used in Example 1 as the organic photoconductive compound. did.

Oxadiazole compound The measurement was performed in the same manner as in Example 1. As a result, all the characteristics showed the same results as those in Example 1.

(Example 6) As an organic photoconductive compound, a hydrazone compound shown below: 25 parts 75 parts of a copolymer: A-1 as a binding resin; the following thiopyrylium salt compound as a sensitizing dye: 1.18 parts Was dissolved in a mixed solvent of 510 parts of methylene chloride and 150 parts of methylcellosolve acetate.

This solution was applied onto a grained aluminum plate having a thickness of 0.25 mm and dried to prepare a printing plate precursor for electrophotographic plate making having a photoconductive layer having a dry film thickness of 5.3 μm.

Next, after charging the sample to a surface potential of +450 V in a dark place, the sample was exposed to light of 632 nm using a He-Ne laser, and was exposed to 10 g of polymethyl methacrylate in Isopar H (Esso Standard) 1. Toner particles (particle size
0.3 μm), and developed with a liquid developer prepared by adding 0.01 g of soybean oil lecithin as a charge control agent,
A clear positive toner image without fog was obtained at both the writing start portion and the writing end portion.

Further, the toner image was fixed by heating at 100 ° C. for 3 minutes.
This electrophotographic printing plate precursor was prepared by adding 70 g of sodium metasilicate hydrate to 140 ml of glycerin and 55 g of ethylene glycol.
The photoconductive layer in the non-image area where no toner was adhered could be completely removed by immersion in an etching solution dissolved in 0 ml and 150 ml of ethanol for about 5 seconds and washing while gently brushing with a stream of water. .

The printing plate produced in this way is Hamadastar 600CD
When printing was carried out by an ordinary method using an offset printing machine, 100,000 sheets of very clear prints without stains in non-image areas could be printed.

(Example 7) X-type metal-free phthalocyanine (manufactured by Dainippon Ink Co., Ltd.) as an organic photoconductive compound 1.9 parts Thiovalpituric acid compound shown below as an additive
... 0.15 copies Copolymer: P-1 17 parts Tetrahydrofuran / cyclohexane (8/2) weight ratio mixed solution 100 parts were put together with glass beads in a 500 ml glass container.
After dispersing for 60 minutes using a paint shaker, the glass beads were separated by filtration to obtain a dispersion for a photoconductive layer.

Next, this dispersion for photoconductive layer was grained to a thickness of 0.25.
Coated and dried on an aluminum plate with a thickness of 6.0 μm
An electrophotographic printing plate precursor having m photoconductive layers was prepared.

[Comparative Examples D] to [Comparative Example F] Each electrophotographic photoreceptor was produced in the same manner as in Example 7, except that the following resins were used instead of the polymer A-1. did.

[Comparative Example D]: [Copolymer B] [Comparative Example E]: [Copolymer C] [Comparative Example F]: [Copolymer D] Benzyl methacrylate-methacrylic acid (75/25) weight ratio MW8 × 10 ^{3 The} following table summarizes the results of the measurements of the electrostatic properties and the imaging properties of these photosensitive materials.

The embodiments of the evaluation items shown in the table are as follows.

Note) Electrostatic properties: Paper analyzer (Kawaguchi Electric Co., Ltd., PAVER ANALYZER SP-428) in a dark room at (temperature 20 ° C, 65% RH) and (temperature 30 ° C, 80% RH) ) after the 20 seconds corona discharge by + 6kV using, allowed to stand for 10 seconds to measure the surface potential V ₁₀ at this time. Next, the potential V ₁₉₀ after standing still in the dark for 180 seconds was measured, and the retention of the potential after dark decay for 180 seconds, that is, the dark decay retention rate [DRR (%)] was determined as (V ₁₉₀ / V ₁₀ ) x100 (%).

After charging the surface of the photoconductive layer to +400 V by corona discharge, it is irradiated with monochromatic light having a wavelength of 780 nm, and the surface potential (V ₁₀ )
The time required for the light to decay to 1/2 is calculated, and the exposure E
Calculate _1/2 (erg / cm ² ).

Further, after charging to +400 V by corona discharge in the same manner as in the E _1/2 measurement, irradiation with monochromatic light having a wavelength of 780 nm was performed, and the surface potential (V
The time required for ₁₀ ) to decay to 1/10 is determined, and the exposure amount E _1/10 (erg / cm ² ) is calculated from this.

Note) Image-capturing property: Each photosensitive material was left for one day and night under the following environmental conditions. Next, it is charged at +5 kV, and using a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength 780 nm) with a 2.8 mW output as a light source, a pitch of 25 μm and a scanning speed of 60 erg / cm ² on the surface of the photosensitive material. After exposure at a speed of 300 m / sec, development and fixing were performed using the liquid developer used in Example 1 and further, a copied image (fog, image quality) obtained by irradiating light was visually evaluated. .

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

With respect to the electrostatic characteristics of each photoconductor, Comparative Example D was inferior to all other photoconductors in all values. On the other hand, Comparative Example E
Compared with Comparative Example D, V ₁₀ , DRR, E _1/2 , E _1/10 were all improved, and even if the environment became severe (30 ° C., 80% RH), the change was relatively small. But it wasn't enough. On the other hand, in the photoreceptor of the present invention and Comparative Example F, the electrostatic properties of all were remarkably improved, and the change was extremely small even if the environment fluctuated. However, Comparative Example F was inferior in light sensitivity to the present invention.

Actually, the copied images of the respective photoconductors, which were taken by scanning and exposing with the semiconductor laser light, corresponded to the above-mentioned electrostatic characteristics, and the present invention was good. Furthermore, when printing was performed after forming an original plate for offset printing in the same manner as in Example 1, only the present invention could print 100,000 sheets.

(Examples 8 to 20) An electrophotographic photoreceptor was prepared in the same manner as in Example 7, except that the copolymer shown in the following table was used instead of the copolymer A-1.

All of the photosensitive materials showed good electrostatic characteristics and good image-capturing properties, and even under severe conditions (30 ° C., 80% RH), they showed good performance equivalent to that of Example 7.

Further, when the offset master was subjected to etching treatment, the non-image portions were immediately eluted in any case.
When actually printed, the image quality of the printed matter after printing 100,000 sheets was a clear image without background fog.

[Effect of the Invention] The printing plate precursor for electrophotographic plate making of the present invention is an excellent printing plate precursor for electrophotographic plate making with improved response speed and etching property, and prints a large number of printed matter faithfully reproducing the original. I was able to realize that. Further, according to the printing plate precursor for electrophotographic plate making of the present invention, the problem is caused by an increase in a residual potential at a writing end portion due to a slow response speed in a direct printing plate by a scanning exposure method such as a laser. The problem of fogging can be solved, and a good printing original plate without fogging can be obtained in both the writing start portion and the writing end portion.

Claims (3)

(57) [Claims] 1. A photoconductive layer containing at least a photoconductive compound and a binder resin on a conductive support, and after image exposure to form a toner image, a photoconductive layer in a non-image portion other than the toner image portion. In a printing original plate for electrophotographic plate making, which is a printing original plate by removing a layer, the binding resin of the photoconductive layer is a monofunctional macromonomer, and only one end of the polymer main chain is as follows. A polymerizable double bond group represented by the general formula [I] is bonded and at least one of the polymer components represented by the following general formula [IIa] or [IIb] having a weight average molecular weight of 2 × 10 ⁴ or less. monofunctional macromonomer containing species, and monomers, represented by the following formula (III), a further monofunctional monomers, -PO ₃ H ₂ group, -SO ₃
H group, -COOH group, phenolic -OH group, ｛R represents a monofunctional monomer containing at least one acidic group selected from｝ groups representing a hydrocarbon group or an —OR ′ group (R ′ represents a hydrocarbon group) and a cyclic acid anhydride-containing group. An electrophotographic printing plate precursor comprising, as a component, a graft copolymer having a weight average molecular weight of 1 × 10 ³ to 1 × 10 ⁵ . General formula (I) 中 In the formula (I), A ₀ represents —COO—, —OCO—, — (CH ₂ ) _L1 OCO
_{-, - (CH 2) L2} COO -, ( an integer of _{L1, L2} is 1~3), - O -, - SO 2 -, - CO-, -CONHCOO-, -CONHCONH-, or (Where R ₁ represents a hydrogen atom or a hydrocarbon group).
a ₁ and a ₂ may be the same or different, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, -COO-D ₁
Or -COO-D ₁ via a hydrocarbon (D ₁ represents a hydrogen atom or a hydrocarbon group which may be substituted). ｝ General formula (IIa) General formula (IIb) {Wherein (II a) or (II b), A ₁ represents the same content as A ₀ in formula (I). B ₁ represents an aliphatic group having 1 to 18 carbon atoms or an aromatic group having 6 to 12 carbon atoms. b ₁ and b ₂ may be the same or different from each other, and in the formula (I)
Represents the same contents as a ₁ and a ₂ . B ₀ is -CN, -CONH ₂ or And J represents a hydrogen atom, a halogen atom, an alkoxy group or —COOD ₄ (D ₄ represents an alkyl group, an aralkyl group or an aryl group). ｝ General formula (III) {Wherein (III), A ₂ represents the same content as A ₁ in formula (II a), B ₂ represents a B ₁ same contents as in formula (II a). c ₁ and c ₂ may be the same or different from each other;
It represents the same contents as a ₁ and a ₂ in the table. ｝ 2. In the binder resin, the following general formulas (Va) and (Va) are used as copolymer components represented by the general formula (III).
The printing original plate for electrophotographic plate-making according to claim 1, further comprising at least one of the aryl group-containing methacrylate components represented by b). General formula (V a) General formula (V b) Wherein G ₁ and G ₂ are each independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a chlorine atom, a bromine atom, -COL ₁ or -COOL ₂ (L ₁ and L ₂ each have Represents 1 to 10 hydrocarbon groups). Z ₁ and Z ₂ each represent a direct bond or a linking group having 1 to 4 linking atoms, each linking —COO— and a benzene ring. ] 3. The bonding resin, wherein only one terminal of the polymer main chain of the graft copolymer is -PO ₃ H ₂ group, -SO ₃ H group, -C
OOH group, phenolic OH group, (1) wherein at least one acidic group selected from the group consisting of (R represents a hydrocarbon group or an -OR 'group (R' represents a hydrocarbon group)) and a cyclic acid anhydride-containing group is bonded. The printing original plate for electrophotographic plate making according to any one of (1) to (2).