JP2001312068A - Original plate of planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative original plate of a planographic printing plate capable of recording with an IR laser, having good adhesion of a photosensitive layer to the base and excellent in image reproducibility and printing resistance. SOLUTION: The original plate is obtained by successively disposing a middle layer containing a compound having a radical polymerization reactive group and a photosensitive layer containing I) an IR absorbent, II) a polymerization initiator and III) a compound having a polymeizable unsaturated group and capable of recording with an IR laser on a base made hydrophilic by treatment. Preferably the compound in the middle layer further has a cationic group in its molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor that can be written with an infrared laser, and more particularly to a lithographic printing plate precursor having a negative recording layer with excellent printing durability.

[0002]

2. Description of the Related Art In recent years, the development of lasers has been remarkable, and in particular, solid lasers and semiconductor lasers having a light emitting region in the near infrared to infrared region have been increasing in output and miniaturization. Therefore, these lasers are very useful as an exposure light source when making a plate directly from digital data of a computer or the like. Using an infrared laser having an emission region in the infrared region as an exposure light source, a negative type lithographic printing plate material for an infrared laser, an infrared absorber, and a polymerization initiator that generates radicals by light or heat,
A lithographic printing plate material having a photosensitive layer containing a polymerizable compound.

As such a negative type image recording material, for example, a heat-polymerized printing plate is disclosed in
Techniques such as those described in JP-A-8621 and JP-A-9-34110 are known. Although these lithographic printing plates are excellent in image-forming properties, a plastic film such as polyethylene terephthalate (PET) or an aluminum substrate as a support was subjected to anodizing (AD) treatment and then subjected to hydrophilic treatment with sodium silicate. Since a substrate is used, there is a problem that adhesion between the substrate and the photosensitive layer is low, image reproducibility such as halftone dots and fine lines is insufficient, and printing durability is low. Various techniques for controlling the composition of the support surface and the photosensitive layer to physically improve the adhesion between the support and the photosensitive layer have been studied. Since there is a concern that the developing property is affected, and there is a problem that a residual film after development may cause stains in the non-image area, there is a demand for an improvement means that does not affect the image reproducibility and sensitivity.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a negative type which is recordable with an infrared laser, has good adhesion between a support and a photosensitive layer, and has excellent image reproducibility and printing durability. Is to provide a lithographic printing plate precursor.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by providing an intermediate layer containing a polymerizable compound on a hydrophilized aluminum substrate. Completed the invention. That is, the lithographic printing plate precursor corresponding to the heat mode of the present invention comprises, on a support subjected to hydrophilic treatment, an intermediate layer containing a compound having a radical polymerization reactive group, and I) an infrared absorber, and II) polymerization initiation. Agent,
And III) a photosensitive layer containing a compound having a polymerizable unsaturated group and being recordable by an infrared laser. Here, in a preferred embodiment, the compound having a radical polymerization reactive group contained in the intermediate layer further has a cationic group.

In the present invention, "corresponding to the heat mode" means that recording by heat mode exposure is possible. The definition of the heat mode exposure in the present invention will be described in detail. Hans-Joachim Tim
pe, IS & Ts NIP 15: 1999 Inte
rational Conference on D
digital printing technology
ies. P. As described in 209, a photoabsorbing substance (for example, a dye) is photoexcited in a photoreceptor material, and undergoes a chemical or physical change to form a chemical or physical change from the photoexcitation of the photoabsorbing substance forming an image. It is known that there are roughly two modes in the above processes. One is that the photo-excited light-absorbing substance deactivates due to some photochemical interaction (eg, energy transfer, electron transfer) with other reactants in the photosensitive material,
As a result, a so-called photon mode in which the activated reactant causes a chemical or physical change required for the above-described image formation, and the other is that the photoexcited light absorbing substance generates heat and deactivates, and the heat is lost. This is a so-called heat mode in which a reactant causes a chemical or physical change required for image formation by utilizing the above-mentioned method. In addition, there are special modes such as ablation in which substances are explosively scattered by the energy of light locally collected and multiphoton absorption in which one molecule absorbs many photons at a time, but these modes are omitted here.

[0007] The exposure processes utilizing the above-described modes are called font mode exposure and heat mode exposure. The technical difference between the font mode exposure and the heat mode exposure is whether or not the energy amount of several photons to be exposed can be added to the energy amount of the target reaction.
For example, consider a case where a certain reaction occurs using n photons. In the font mode exposure, photochemical interaction is used, so that the energy of one photon cannot be added and used due to the requirement of the law of conservation of quantum energy and momentum. That is, in order to cause a certain reaction, the relationship of “energy amount of one photon ≧ energy amount of reaction” is necessary. On the other hand, in heat mode exposure, heat is generated after light excitation, and light energy is converted into heat and used, so that the amount of energy can be added. Therefore, the relationship “energy amount of n photons ≧ energy amount of reaction” is sufficient. However, this energy addition is restricted by thermal diffusion. In other words, if the next photoexcitation-deactivation process occurs and heat is generated before heat escapes from the exposed portion (reaction point) of interest by thermal diffusion, the heat is reliably accumulated and added, and the temperature rises in that portion. Leads to. However, when the next heat is generated slowly, the heat escapes and is not accumulated. In other words, in the heat mode exposure, even if the total exposure energy is the same, the result is different between the case where the high energy light is irradiated for a short time and the case where the low energy light is irradiated for a long time. It becomes advantageous for accumulation of. Of course,
In the font mode exposure, a similar phenomenon may occur due to the influence of the diffusion of the subsequent reactive species, but basically, this does not occur.

That is, in terms of the characteristics of the photosensitive material, in the font mode, the intrinsic sensitivity of the photosensitive material (reaction required for image formation) is compared with the exposure power density (w / cm ² ) (= energy density per unit time). Energy amount) is constant, but in the heat mode, the intrinsic sensitivity of the photosensitive material increases with respect to the exposure power density. Therefore, if the exposure time is fixed so that the productivity necessary for practical use as an image recording material can be maintained, the font mode exposure is usually about 0.1 mJ / c when comparing the modes.
Although a high sensitivity of about m ² can be achieved, the reaction occurs even with any small amount of exposure, so that the problem of low-exposure fog in the unexposed area is likely to occur. On the other hand, in the heat mode exposure, a reaction does not take place unless the exposure amount exceeds a certain level, and usually 50 mJ / cm ^{2 in} view of the thermal stability of the photosensitive material.
Although required, the problem of low exposure fog is avoided. And, in fact heat mode exposure requires exposure power density at the plate surface of the photosensitive material is 5000 W / cm ² or more, preferably it is necessary to 10000 W / cm ² or more. However, although not described in detail here, 5.0 × 1
When a high power density laser of 0 ⁵ / cm ² or more is used, ablation occurs, which is not preferable because of problems such as staining the light source.

In the present invention, by disposing a compound having a radical polymerizable group as an intermediate layer between the support and the photosensitive layer, heat generation by heat mode exposure used for image recording causes heat generation of the intermediate layer. The polymerization reaction of the compound having a radical polymerizable group is also performed inside, and the adhesion between the substrate and the photosensitive layer is improved. In particular, when the compound having a radical polymerization reactive group, which is a preferred embodiment of the present invention, has a cationic group or an acid group, the action of these functional groups in the heated region causes the intermediate layer and the substrate or the support to act. Interaction is strengthened, and the adhesion is further improved. Further, since the intermediate layer has a hydrophilic group such as a cationic group, an acid group, a carboxylic acid group, a phosphoric acid group, a hydroxyl group, an amine, and a sulfonic acid group, it exhibits excellent developability in an unexposed area, A stain prevention effect is exhibited.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The lithographic printing plate precursor according to the invention is provided with an intermediate layer, which will be described in detail below, and a heat-mode-compatible negative photosensitive layer on a support in this order. If necessary, known layers such as a surface protective layer and a back coat layer may be provided as long as the effects of the present invention are not impaired. The intermediate layer in the present invention can be provided on an anodized aluminum substrate or an aluminum substrate that has been subjected to anodizing treatment (hereinafter referred to as AD treatment) and then subjected to hydrophilic treatment with sodium silicate or the like.

[Intermediate Layer] First, the intermediate layer, which is a characteristic part of the lithographic printing plate precursor according to the invention, will be described. As the compound having a radical polymerization reactive group used in the intermediate layer of the present invention, JP-A-9-34104, paragraph [0]
014] to [0015], compounds having a hydrophilic ethylenically unsaturated bond can be used. By using a hydrophilic compound, excellent solubility is exhibited in the unexposed area, and in the exposed area, the permeability of the developer is suppressed by polymerization, and the adhesiveness and adhesion are improved. Further, polymerization is promoted in the exposed portion due to heat generated during exposure, and the adhesion becomes stronger. Preferred compounds having a hydrophilic ethylenically unsaturated bond include, from the viewpoint of adhesion and developability,
Compounds having a phosphoric acid group, a carboxylic acid group, a hydroxyl group, or a cationic group are preferred. Further, a polymer or the like which is a compound having an ethylenically unsaturated bond shown below can be used. Further, a monomer for synthesizing the polymer can also be suitably used for forming the intermediate layer. The polymer used for forming the intermediate layer according to the present invention preferably has an acrylic resin, a styrene resin, or a copolymer thereof, a urethane resin, a polyester resin, or a polyamide resin in its main chain structure. An acrylic resin, a styrene resin, or a copolymer thereof is preferable from the viewpoints of printing durability and synthesis suitability. Further, the molecular weight can be arbitrarily set by the performance design of the lithographic printing plate precursor. If the weight average molecular weight is low, favorable results are obtained in terms of stain resistance, and if the weight average molecular weight is high, printing durability is improved. Preferred weight average molecular weights are 2,000 to 1,
00000, more preferably 5,000 to 100,0
00.

The radical polymerization reactive groups present in these compounds include unsaturated bonds capable of addition polymerization (for example, (meth) acryloyl group, (meth) acrylamide group,
(Meth) acrylonitrile group, allyl group, styrene structure, vinyl ether structure, acetylene structure, etc.), -S
H, -PH, SiH, -GeH, a disulfide structure and the like. From the viewpoint of printing durability, an unsaturated bond group capable of addition polymerization is preferable. Here, the (meth) acryl group represents an acryl group or a methacryl group.
In addition, the compound constituting the intermediate layer preferably has a cationic group in the molecule in addition to the radical polymerization reactive group.

Examples of the cationic group include a cationic group composed of an atom of Group V or Group VI of the periodic table, preferably a cationic group composed of a nitrogen atom, a phosphorus atom or a sulfur atom, and more preferably. Is a cationic group consisting of a nitrogen atom.

Hereinafter, specific methods for synthesizing a polymer having a cationic group and a radical polymerization reactive group according to the present invention will be described below, but the present invention is not limited thereto. Acrylic Resin, Styrene Resin, or Copolymer Thereof As a method for introducing a cationic group and a radical polymerization reactive group into an acrylic resin, styrene resin, or a copolymer thereof, the following -1) to -5) and the like.

-1) An acrylic or styrene monomer having a cationic group and an acrylic or styrene monomer having at least one reactive functional group are copolymerized to form a polymer having the reactive group in a side chain. A method in which a compound having both a group capable of reacting with the reactive functional group and a radical polymerization reactive group at the same time is polymerized to the obtained polymer to introduce a radical polymerization reactive group. Examples of the acrylic or styrene-based monomer having a cationic group include compounds represented by the following general formulas (1) to (3).

[0016]

Embedded image

In the formula, R ¹ is a hydrogen atom or a methyl group, R ²
Represents a substituent. R ³ represents an alkyl group which may have a substituent having 1 to 20 carbon atoms, or an aralkyl group. A represents an oxygen atom or NR ^4,. (R ⁴ represents a hydrogen atom or a hydrocarbon group which may have a substituent having 1 to 10 carbon atoms.) J represents a single bond or a divalent linking group, and D represents a cationic group. Represents a group. Z ^- is a halogen _{^{ion, C10 4 -, BF 4 -}} , PF 6 -, Sb
Represents a monovalent anion selected from the group consisting of F ₆ ⁻ , SO ₃ ⁻ , alkyl sulfonate ions, and aryl sulfonate ions. p represents an integer of 0 to 4;
When it is ４4, R ² may be the same or different from each other.

As R ² , any substituent consisting of a nonmetallic atom can be mentioned. More preferred substituents are a halogen atom (a fluorine atom, a chlorine atom, a bromine atom and an iodine atom) and a carbon atom number. Is an alkyl group or an alkoxyl group which may have 1 to 5 substituents.

R ³ represents an alkyl group which may have a substituent having 1 to 20 carbon atoms or an aralkyl group. Preferred examples thereof include a methyl group, an ethyl group and an n-pentyl group. , I-pentyl, neopentyl, n-hexyl, cyclohexyl, methoxyethyl, 2-hydroxypropyl, carboxymethyl, 1,2-epoxypropyl, 2-methylthioethyl, 2- (methoxy Carbonyl) ethyl group, 4-chlorohexyl group, 2-methyl-2-pentenyl group, perfluorohexyl group, -CH ₂ CH ₂ SO ₃ ^- group (in this case,
Z ^- is not required), tetrahydrofurfuryl group, a benzyl group, 4-(t-butyl) benzyl group, 3,5-bis (trifluoromethyl) benzyl group, naphth-2-yl - methyl group, and phenethyl group No.

J is a single bond or a divalent linking group,
As the divalent linking group, any linking group consisting of a non-metallic atom can be exemplified. More preferred linking groups include
-O -, - S -, - NR 4 -, - CO -, - SO 2 -, -
^{NR 4 CO -, - NR 4} COO-, or -NR ⁴ CON
R ⁴ - (. R ⁴ has the same meaning as in general formula (1) where, if R ⁴ is present in plurality, they may be the same or different.) Consisting of It may be interrupted one or more times by a group selected from the group, and examples thereof include divalent hydrocarbon groups having 1 to 20 carbon atoms which may have a substituent. More preferably, it is an uninterrupted or unsubstituted hydrocarbon group of 1 to 20 carbon atoms.

D represents a cationic group, specifically a cationic group represented by the following general formulas (4) to (6).

[0022]

Embedded image

In the formula, R ^{5 to} R ⁷ each independently represent a hydrogen atom or an alkyl group, an aryl group, or an aralkyl group which may have a substituent having 1 to 20 carbon atoms, and R ⁸ represents Represents an alkylidene group which may have a substituent having 1 to 20 carbon atoms. R ^{4 to} R ⁸ may be linked to each other or to a part of J to form a ring. Y ¹ represents a nitrogen atom or a phosphorus atom, and Y ² represents a sulfur atom. Z ^- has the same meaning as in formula (3).
Among the cationic groups represented by the general formulas (4) to (6), the cationic group represented by the general formula (4) or (5), furthermore, Y ¹ is a nitrogen atom because of easy synthesis. Groups are particularly preferred.

Specific examples of acrylic and styrene monomers having a cationic group are shown below, but the present invention is not limited to these. (Specific examples of monomers having a cationic group)

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

[0029]

Embedded image

Examples of the acryl or styrene monomer having at least one reactive functional group include acrylate, methacrylate, acrylamide, methacrylamide and styrene represented by the following general formula (7) or (8). Derivatives can be mentioned.

[0031]

Embedded image

In the formula, E is a hydroxyl group, a carbonyl halide group, a carboxyl group or a salt thereof, an amino group,
It represents a reactive functional group selected from the group consisting of an epoxy group and a haloalkyl group. A, R ¹ , R ² , J and p have the same meanings as in formulas (1) and (2).

Specific examples of such an acrylic or styrene-based monomer having at least one reactive functional group include hydroxyl groups described in "Polymer Data Handbook-Basic Edition-(Polymer Society, Baifukan, 1986)". Group, a carbonyl halide group, a carboxyl group or a salt thereof, an amino group, an epoxy group, and an acrylic acid having a reactive functional group selected from the group consisting of a haloalkyl group, a methacrylic acid derivative, an acrylate derivative,
Examples include methacrylic acid ester derivatives, acrylamide, and methacrylamide derivatives.

When an acrylic or styrene monomer having at least one reactive functional group and an acrylic or styrene monomer having a cationic group are copolymerized to form a polymer having the reactive functional group in a side chain, Alternatively, an acrylic or styrene monomer having at least one reactive functional group may be used alone, or two or more kinds may be used in combination. Further, an acrylic or styrene monomer having a cationic group may be used alone or in combination of two or more.

Further, if necessary, one or more other monomers may be further combined and copolymerized to obtain a tertiary or higher copolymer. Such monomers include:
From the viewpoint of imparting alkali developability to the intermediate layer, it is preferable to use a monomer having an acid group. Preferred as acid groups, an acid dissociation constant (pKa) of 7 or less of the acid groups, more preferably, -COOH, -SO ₃ H, -
_{OSO 3 H, -PO 3 H 2} , -OPO 3 H 2, -CONHS
O ₂ — or —SO ₂ NHSO ₂ —. Specific examples of such a monomer include those described in JP-A-11-84674. As the copolymerization method, a conventionally known polymerization method can be used, and the form of the polymer is preferably a random copolymer, a block copolymer, or a graft copolymer.

The polymer having a reactive functional group in the side chain obtained by the above-described method is combined with a compound having a group capable of reacting with the reactive functional group and a radical polymerization reactive group simultaneously by a method selected from the following reactions. Thus, a polymer having a cationic group and a radical polymerization reactive group in the present invention is obtained by introducing a radical polymerization reactive group into a polymer.

(A) a hydroxyl group of a polymer side chain;
Urethane reaction using isocyanates having a radical polymerization reactive group (b) A hydroxyl group in a polymer side chain and a carboxylic acid, a carboxylic acid halide, a sulfonic acid halide or a carboxylic anhydride having a radical polymerization reactive group Esterification reaction used (c) a carboxyl group of a polymer side chain or a salt thereof,
Esterification reaction using isocyanates having a radical polymerization reactive group (d) Esterification reaction using a carbonyl group, a carboxyl group or a salt thereof in a polymer side chain and an alcohol having a radical polymerization reactive group

(E) Amidation reaction using a carbonyl group, a carboxyl group or a salt thereof of a polymer side chain with an amine having a radical polymerization reactive group. (F) An amino group of a polymer side chain and radical polymerization Ureaization reaction using isocyanates having a reactive group (g) An amino group in a polymer side chain and a carboxylic acid, a carboxylic acid halide, a sulfonic acid halide, or a carboxylic anhydride having a radical polymerization reactive group Amidation reaction used (h) Ring-opening reaction between epoxy group on polymer side chain and various nucleophilic compounds having radical polymerization reactive group (i) Haloalkyl group on polymer side chain and radical polymerization reactive group Reaction with alcohols

-2) After polymerizing monomers represented by the following general formulas (9) to (11) to form a polymer, a compound having both a haloalkyl group and a radical polymerization reactive group is reacted to form a cationic group and a radical A method of simultaneously introducing a polymerization reactive group.

[0040]

Embedded image

In the formula, R ¹ , R ² , A, J, and p have the same meanings as in formulas (1) and (2). G represents a group represented by the following general formula (12) or (13).

[0042]

Embedded image

In the formula, R ⁵ , R ⁶ , Y ¹ and Y ² have the same meanings as in formulas (4) to (6). R ⁵ and R ⁶ may be linked to each other or to a part of J to form a ring. Among the groups represented by the general formulas (12) and (13), a group in which Y ¹ is a nitrogen atom is particularly preferable because of easy synthesis.

Specific examples of the monomers represented by the general formulas (9) to (11) include 7-amino-3,7-dimethyloctyl methacrylate, 2- (5-ethyl-2-pyridyl) ethyl acrylate, (Dimethylamino) ethyl acrylate, 3- (dimethylamino) phenyl acrylate, 2- (dimethylamino) -2-methylpropyl acrylate, 2-hydroxy-3-piperidinopropyl acrylate, (2-diethylamino) ethyl methacrylate, Dicyclohexylamino) ethyl methacrylate, N- (2-dimethylaminoethyl) acrylamide, N-2- (morpholinoethyl) acrylamide, N- (3-diethylaminopropyl) acrylamide, N- (1,1-dimethyl-3-dimethylamino) Propyl) acrylamide, N- (1,3-dimethylmorpholinobutyl) acrylamide, N- (1,3-dimethylpyrrolidinobutyl) acrylamide, N- [4- (phenylamino) phenyl] acrylamide, N- (2-dimethylaminoethyl) methacryl Amide, N- (2,2
-Dimethyl-3-dimethylaminopropyl) methacrylamide, aminostyrene, N, N-dimethylaminostyrene, 4-amino-3-nitrostyrene, (aminomethyl) styrene, vinylbenzyldiallylamine, N-
(Vinylbenzyl) piperidine, N- (vinylbenzyl) morpholine, (2-aminoethyl) styrene, (diethylaminoethyl) styrene, (vinylphenyl) methylsulfide, (vinylphenyl) methylsulfide, vinylpyridine, 2-vinyl-5 -Methylpyridine, 5-ethyl-2-vinylpyridine, 5-bromo-3
-Vinyl pyridine and the like.

The monomers represented by formula (8) or (9) may be used alone or in combination of two or more. If necessary, one or more other monomers may be further combined and copolymerized to form a binary or more copolymer. As such a monomer, the aforementioned monomer having an acid group is preferable.

By reacting the polymer obtained by polymerizing the monomers represented by the general formulas (9) to (11) with a compound having both a haloalkyl group and a radical polymerization reactive group, a cation is obtained. The radical group and the radical polymerization reactive group can be introduced simultaneously, and the polymer having the cationic group and the radical polymerization reactive group in the present invention can be obtained. At this time, the compound having a haloalkyl group and a radical polymerization reactive group simultaneously may be used alone or in combination of two or more.

Specific examples of the compound having both a haloalkyl group and a radical polymerization reactive group include 3-bromo-1
-Propyne, 1-bromo-2-butyne, 6-bromo-1
-Hexyne, 2-bromoethyl vinyl ether, 3-iodopropyl vinyl ether, 6-iodohexyl vinyl ether, 2-bromoethyl acrylate, cinnamyl bromide, chloromethylstyrene, vinylbenzyl bromide, allyl bromide, allyl iodide and the like. .

-3) The following general formula (14) or (1)
After polymerizing the monomer represented by 5) to obtain a polymer having a —CH ₂ X group in the side chain, the following general formulas (16) to (1)
A method in which the compound represented by 8) is reacted to simultaneously introduce a cationic group and a radical polymerization reactive group.

[0049]

Embedded image

Wherein R ¹ , R ² , R ⁵ , R ⁶ , A, J,
Y ¹ , Y ² and p have the same meanings as in formulas (1) to (6). X represents an atom selected from the group consisting of chlorine, bromine and iodine. M represents a radical polymerization reactive group.

Specific examples of the compound represented by the general formula (14) or (15) include 2-bromoethyl acrylate, chloromethylstyrene, bromomethylstyrene and the like. The monomers represented by the general formula (14) or (15) may be used alone or in combination of two or more. If necessary, one or more other monomers may be further combined and copolymerized to form a binary or more copolymer. As such a monomer, the aforementioned monomer having an acid group is preferable.

The polymer having a —CH ₂ X group in the side chain obtained by polymerizing the monomer represented by the general formula (14) or (15) reacts with the —CH ₂ X group to form a cationic group. Is reacted with the compounds represented by the general formulas (16) to (18) having a radical polymerization reactive group at the same time, whereby a cationic group and a radical polymerization reactive group are simultaneously introduced into the polymer, A polymer having a cationic group and a radical polymerization reactive group in the present invention is obtained.

Specific examples of the compounds represented by the general formulas (16) to (18) include, in addition to the compounds shown as specific examples of the monomers represented by the general formulas (9) to (11), 1-diethylamino -1-hexyne, 2-dimethylaminoethyl vinyl ether, diethanolamine monovinyl ether, 2-phenylaminoethyl vinyl ether, 2-pyrrolidylethyl monovinyl ether, 2-methylthioethyl vinyl ether, 2-allylthioethyl vinyl ether, 3-neopentylthiopropyl Vinyl ether,
3-benzylthiopropyl vinyl ether, 2-phenylthioethyl vinyl ether, triallylamine, 3-
(4-dimethylaminophenyl) -2- (4-methoxyphenyl) acrylonitrile, diallyl sulfide, pyridylacetylene and the like.

Among the compounds represented by the general formulas (16) to (18), the compounds represented by the general formula (1)
A compound represented by formula (6) or (17), wherein Y ¹ is a nitrogen atom, or a compound represented by formula (18) is particularly preferred. The general formula (16) or (17)
May be used alone or in combination of two or more.

-4) A method of copolymerizing a monomer having a cationic group and an acrylic or styrene monomer having a radical polymerization reactive group having a relatively slow reaction rate. Examples of the monomer having a cationic group include those represented by the aforementioned general formulas (1) to (3). The acrylic or styrene-based monomer having a radical polymerization reactive group having a relatively slow reaction rate includes an acrylic or styrene structure forming a main chain skeleton by polymerization, and an unsaturated bond having a lower addition polymerization property (for example,
Allyl group, acetylene structure, etc.).

The monomer has at least two radical polymerization reactive groups having different reactivities in the molecule, but when copolymerized with a monomer having a cationic group, the radical reactivity of an acryl or styrene structure is high. For,
A radical polymerization reactive group having a relatively slow reaction rate does not participate in the polymerization. Therefore, a radical polymerization reactive group can be introduced into a side chain without causing gelation, and a polymer having a cationic group and radical reactivity in the present invention can be obtained.

Preferred specific examples of the acrylic or styrenic monomer having a radical polymerization reactive group having a relatively slow reaction rate include allyl acrylate, allyl methacrylate, allyloxymethyl methacrylate, acetylmethyl methacrylate, 2-propynyl acrylate, 2-propynyl acrylate, Methyl-2-propynyl acrylate, 3-butynyl acrylate, N-allylacrylamide, N-
Allyl methacrylamide, allyl styrene, (vinyl phenyl) allyl ether, (vinyl phenyl) acetylene, etc. are mentioned.

The monomer having a cationic group and the monomer having a radical polymerization reactive group having a relatively slow reaction rate may be used alone or in combination of two or more. If necessary, one or more other monomers may be further combined and copolymerized to form a tertiary or higher copolymer. As such a monomer, it is preferable to use the above-described monomer having an acid group from the viewpoint of imparting alkali developability to the intermediate layer.

-5) A method of polymerizing a monomer having a radical polymerization reactive group and a cationic group having a relatively low reaction rate at the same time. As a monomer having both a radical polymerization reactive group and a cationic group having a relatively slow reaction rate,
Compounds represented by formulas (19) to (21) can be given.

[0060]

Embedded image

Wherein R ¹ , R ² , A, J, Z ⁻ , and p
Has the same meaning as in formulas (1) to (3). R ² represents an alkyl group or an aralkyl group having a radical polymerizable group having lower reactivity than the styrene structure forming the main chain skeleton. D ′ represents a cationic group represented by the following general formulas (22) to (24).

[0062]

Embedded image

In the formula, Y ¹ , Y ² and Z ⁻ have the same meanings as in formulas (4) to (6). R ^{11 to} R ¹² each independently represent a hydrogen atom, or an alkyl group or an aryl group which may have a substituent having 1 to 20 carbon atoms,
R ¹³ represents an aralkyl group, and R ¹³ represents an alkylidene group which may have a substituent having 1 to 20 carbon atoms. However, in the general formula (22), R ^{10 to} R ¹² and the general formula (2)
3) R ¹⁰ or R ¹³ in in formula (24) has a low radical polymerizable group reactive than acrylic or styrene structure forms a main chain skeleton to at least one of R ¹⁰ or R ¹¹ I have. Also, if possible,
R ^{10 to} R ¹³ may be bonded to each other or to any part of J to form a ring.

Among the cationic groups represented by the general formulas (22) to (24), since the synthesis is easy, the cationic group is represented by the general formula (22) or (23), and Y ¹ is a nitrogen atom. Certain groups are particularly preferred. Specific examples of the monomer having a radical polymerization reactive group and a cationic group having a relatively low reaction rate at the same time are shown below, but the present invention is not limited thereto.

[0065]

Embedded image

[0066]

Embedded image

Among the compounds constituting the intermediate layer of the present invention,
From the viewpoints of adhesion to the substrate and developability, a compound having phosphorus or a cation moiety in addition to the radical polymerization reactive group is preferred. Further, from the viewpoint of printing durability and adhesion, a polymer having an ethylenically unsaturated bond is preferable, and a compound having the ammonium or pyridinium salt structure is more preferable.

The intermediate layer in the lithographic printing plate precursor according to the present invention can be provided by the following method. That is,
A solution obtained by dissolving the polymer having a radical polymerization reactive group in an organic solvent such as water or methanol or ethanol or a mixed solvent thereof is applied to a hydrophilized aluminum support, and dried to form an intermediate layer. The method of providing, and immersing the aluminum support subjected to hydrophilization treatment in a solution in which the polymer having the radical polymerization reactive group is dissolved in water or an organic solvent such as methanol or ethanol or a mixed solvent thereof, and This is a method in which a polymer having a radical polymerization reactive group is adsorbed and then washed and dried with water or the like to form an intermediate layer. In the former method, the radical polymerization reactive group is added in an amount of 0.005 to
A coating solution dissolved at a concentration of 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used.
In the method of washing with water or the like after immersion in a solution in which the compound of the present invention is dissolved, the concentration of the solution is 0.01 to 2
0% by weight, preferably 0.05 to 5% by weight, the immersion temperature is 20 ° C to 90 ° C, preferably 25 ° C to 50 ° C, and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds. Seconds ~
One minute.

The coating amount of the intermediate layer after drying was 2 mg / m
^{2 to} 200 mg / m ² is suitable, preferably 5 mg / m ^2.
m ² ~100mg / m ^2, more preferably 5 mg / m ²
５０50 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. Also, 200
If the amount is more than mg / m ² , sufficient printing durability cannot be obtained. The solution used when providing the intermediate layer in the lithographic printing plate precursor of the present invention is ammonia, triethylamine,
The pH can be adjusted with a basic substance such as potassium hydroxide or an acidic substance such as hydrochloric acid, sulfuric acid, phosphoric acid, sulfonic acid, or carboxylic acid, and the pH can be used in the range of 1 to 12.
In addition, as a coating method, a method of applying under an acidic condition of an intermediate layer described in JP-A-7-314937 or JP-A-5-278362, or a method of previously treating a silicate with an acid is used to obtain a close contact. Properties can be further enhanced. A yellow dye may be added to the intermediate layer for the purpose of improving the tone reproducibility of the lithographic printing plate precursor.

In the intermediate layer of the lithographic printing plate precursor according to the present invention, a known phosphonic acid having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, glycine or β-alanine may be used. And a hydrochloride of an amine having a hydroxyl group such as a hydrochloride of triethanolamine. The intermediate layer of the present invention desirably contains at least 20% by weight or more of the polymer having the radical polymerization reactive group, more preferably 5% by weight or more.
It is at least 0% by weight, most preferably at least 80% by weight.
The intermediate layer is disclosed in JP-A-9-34104 and JP-A-10-2104.
Other components as described in Japanese Patent No. 60536, for example, a binder polymer, a photopolymerizable compound, a photopolymerization initiator and the like can be added according to the purpose.

[Support] As the support used in the lithographic printing plate precursor according to the invention, a support subjected to hydrophilic treatment, in particular, a hydrophilic treated aluminum which has good dimensional stability and is relatively inexpensive. Plates are preferred. A suitable aluminum substrate used for the support is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Particularly preferred aluminum in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate is approximately 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm.
mm, particularly preferably 0.2 to 0.3 mm.

The support used in the lithographic printing plate precursor according to the present invention is preferably one that has been subjected to hydrophilic treatment by the following steps. The aluminum plate is first subjected to a surface roughening treatment. Prior to the surface roughening, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an aqueous alkali solution for removing rolling oil on the surface is performed. The surface roughening treatment of the aluminum plate is performed by various methods.
For example, it is performed by a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically selectively dissolving the surface. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. In addition, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can be used. The aluminum plate thus roughened is subjected to an anodic oxidation treatment, if necessary, through alkali etching treatment and neutralization treatment to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. Generally, sulfuric acid, phosphoric acid,
Oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The anodizing treatment conditions vary depending on the electrolyte used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C.
Current density 5 to 60 A / dm ^2, voltage 1 to 100 V, which is an electrolyzing time of 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide coating is less than 1.0 g / m ² , the printing durability is insufficient, and the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing. "Scratch dirt" is likely to occur. Although such anodizing treatment is performed on a surface used for printing of the support of lithographic printing plates, the back around the electric lines of force, 0.01 to 3 g / m ² on the back surface
Is generally formed.

The surface of the support is made hydrophilic after the anodic oxidation treatment, and a conventionally known treatment method is used. As such a hydrophilic treatment,
U.S. Pat. Nos. 2,714,066 and 3,181,4
No. 61, No. 3,280,734 and No. 3,902,7
There is an alkali metal silicate (for example, an aqueous solution of sodium silicate) as disclosed in JP-A-34. In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, Tokuboku Sho 36
Potassium fluoride zirconate disclosed in U.S. Pat. No. 2,220,632 and U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689,272. A method of treating with polyvinyl phosphonic acid is used. Among these, a particularly preferred hydrophilization treatment in the present invention is a silicate treatment. The silicate treatment will be described below.

The anodic oxide film of the aluminum plate treated as described above is coated with an alkali metal silicate of 0.1 to 30%.
% By weight, preferably 0.5 to 10% by weight,
Aqueous solution having a pH of 10 to 13, for example, 15 to 8
Immerse at 0 ° C for 0.5-120 seconds. If the pH of the aqueous alkali metal silicate solution is lower than 10, the solution gels and 13.0.
If it is higher, the oxide film will be dissolved. As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used. Hydroxides used to increase the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, an alkaline earth metal salt or a Group IVB metal salt may be added to the above-mentioned processing solution. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate, and water-soluble salts such as sulfates, hydrochlorides, phosphates, acetates, oxalates and borates. No. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium titanium oxalate,
Titanium sulfate, titanium tetraiodide, zirconium chloride oxide,
Zirconium dioxide, zirconium oxychloride, zirconium tetrachloride and the like can be mentioned. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. The preferred range of these metal salts is 0.01 to 10% by weight, and the more preferred range is 0.05 to 5.0% by weight. Since the silicate treatment further improves the hydrophilicity on the aluminum plate surface, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

On the back surface of the support, a back coat is provided if necessary. Examples of the back coat include a coating comprising a metal oxide obtained by hydrolyzing and polycondensing an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. Layers are preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si (OC
_{2 H 5) 4, Si (} OC 3 H 7) 4, Si (OC
Alkoxy compounds of silicon such as ₄ H ₉ ) ₄ are inexpensive and readily available, and a coating layer of a metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

[Photosensitive layer] In the lithographic printing plate precursor according to the invention,
An intermediate layer is provided on the support, and further, a photosensitive layer containing I) an infrared absorber, II) a polymerization initiator, and III) a compound having a polymerizable unsaturated group and recordable by an infrared laser is provided. Provide.

Hereinafter, other components of the photosensitive layer will be described. The composition constituting the photosensitive layer includes: I) an infrared absorber;
It is a heat (photo) polymerizable composition containing I) a polymerization initiator, III) a compound having a polymerizable unsaturated group, and preferably, IV) a binder insoluble in water and soluble in an aqueous alkali solution. Examples of the thermopolymerizable composition that can be used in the present invention include JP-A-8-108621 and JP-A-9-108621.
And JP-A-7-306528, for example, a composition constituting a light-sensitive and heat-sensitive image recording layer.

I) Infrared absorbent In the present invention, the infrared absorbent contained in the photosensitive layer is a substance having a photothermal conversion function of generating heat by irradiation with an infrared laser. The infrared absorber used in the present invention is preferably a dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm.

As the dye, commercially available dyes and known dyes described in literatures such as "Dye Handbook" (edited by The Society of Synthetic Organic Chemistry, Japan, 1970) can be used. Specifically, dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes Is mentioned.

Preferred dyes include, for example, those described in
Cyanine dyes described in JP-A-8-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, etc .;
No. 96, JP-A-58-181690, JP-A-58-1
No. 94595, etc., methine dyes described in
8-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996,
Naphthoquinone dyes described in JP-A-60-52940 and JP-A-60-63744;
Squarylium dyes described in No. 12792, etc.,
Cyanine dyes described in British Patent 434,875 and the like can be mentioned.

Further, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted aryl benzo (thio) described in US Pat. No. 3,881,924 is also preferable. Pyrylium salt, JP-A-57-142645
No. (U.S. Pat. No. 4,327,169) described in JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, and JP-A-59-41363.
Nos. -84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranyl compounds, cyanine dyes described in JP-A-59-216146, pentamethinethiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fairness 5-13
Pyrylium compounds disclosed in JP-A-514 and JP-A-5-19702 are also preferably used.

As another preferred example of the dye, US Pat. No. 4,756,993 discloses a compound represented by the formula (I):
Near-infrared absorbing dyes described as (II) can be mentioned.

Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Further, a cyanine dye is preferable, and a cyanine dye represented by the following general formula (I) is most preferable.

[0085]

Embedded image

In the general formula (I), X ¹ is a halogen atom,
Or an X ² -L ^1. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of storage stability of a photosensitive layer coating liquid, R ¹ and R ² are preferably a hydrocarbon group having two or more carbon atoms, further, R ¹ and R ²
And particularly preferably combine with each other to form a 5- or 6-membered ring.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred examples of the substituent include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different, and represent a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms,
Examples include a carboxyl group and a sulfo group. R ⁵ , R ⁶ , R
⁷ and R ⁸ may be the same or different,
It represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the viewpoint of availability of raw materials, a hydrogen atom is preferable. Z ^1- represents a counter anion. However, when any of R ^{1 to} R ⁸ is substituted with a sulfo group, Z ^1- is not required. Preferred Z ¹⁻ is, from the storage stability of the photosensitive layer coating solution, a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion,
And sulfonate ions, particularly preferably perchlorate ion, hexafluorophosphate ion and arylsulfonate ion.

In the present invention, specific examples of the cyanine dye represented by formula (I) which can be suitably used include paragraph [0] of Japanese Patent Application No. 11-310623.
017] to [0019].

The pigment used in the present invention includes:
Commercial Pigment and Color Index (CI) Handbook,
"Latest Pigment Handbook" (edited by Japan Pigment Technical Association, 1977), "Latest Pigment Application Technology" (CMC Publishing, 1986), "Printing Ink Technology" CMC Publishing, 1984)
Can be used.

The types of pigments include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer-bound dyes. Specifically, insoluble azo pigments, azo lake pigments, condensation azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyeing lake pigments,
Azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used.
Preferred among these pigments is carbon black.

These pigments may be used without surface treatment, or may be used after surface treatment. Examples of the surface treatment include a method of surface coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (eg, a silane coupling agent, an epoxy compound, a polyisocyanate, etc.) to the pigment surface. Can be considered. The above surface treatment methods are described in "Properties and Applications of Metallic Soap" (Koshobo),
It is described in "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986).

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.
Is preferably within the range. Pigment particle size 0.01μ
If it is less than m, the dispersion is not preferred in terms of stability in the coating solution of the image-sensitive layer.

As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. For details, refer to “Latest Pigment Application Technology” (CMC Publishing, 1
986).

These infrared absorbers may be added to the same layer as the other components, or may be added to another layer provided separately. However, when the negative type lithographic printing plate precursor is prepared, Preferably, the optical density of the photosensitive layer at the absorption maximum in the wavelength range of 760 nm to 1200 nm is between 0.1 and 3.0. Outside of this range, sensitivity tends to decrease. Since the optical density is determined by the amount of the infrared absorbing agent added and the thickness of the recording layer, a predetermined optical density can be obtained by controlling both conditions. The optical density of the recording layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a coating layer after drying is formed to a recording layer having a thickness appropriately determined in a range necessary for a lithographic printing plate, and a transmission type optical densitometer is used. Examples include a method of measuring, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.

II) Polymerization Initiator The polymerization initiator is used in combination with the above-mentioned I) infrared absorber, and generates a radical by thermal energy generated by the infrared absorber when irradiated with an infrared laser. A compound that initiates and promotes the polymerization of a compound having an unsaturated group. In the present invention, the polymerization initiator,
Not only those that decompose by the thermal energy and generate polymerization initiator components such as radicals, but also those that function as initiators by the light energy of the infrared laser itself, or that function as polymerization initiators by both heat and light energy To include. As the polymerization initiator, known thermal polymerization initiators, infrared-sensitive photopolymerization initiators and the like can be selected and used, for example, onium salts, triazine compounds having a trihalomethyl group, peroxides,
Examples thereof include an azo-based polymerization initiator, an azide compound, and a quinonediazide. Onium salts are preferred because of their high sensitivity. The onium salt that can be suitably used as a polymerization initiator in the present invention will be described. Preferred onium salts include iodonium salts, diazonium salts, and sulfonium salts. In the present invention, these onium salts function not as acid generators but as radical polymerization initiators. Onium salts suitably used in the present invention are onium salts represented by the following general formulas (III) to (V).

[0096]

Embedded image

In the formula (III), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms which may have a substituent. When the aryl group has a substituent, preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a 12 or less carbon atom. Aryloxy groups. Z ^11- represents a counter ion selected from the group consisting of a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, and is preferably a perchlorate ion or a hexafluorophosphate. And arylsulfonate ions.

In the formula (IV), Ar ²¹ represents an optionally substituted aryl group having 20 or less carbon atoms. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and a 12 or less carbon atom. Alkylamino group, dialkylamino group having 12 or less carbon atoms, 1 carbon atom
An arylamino group having 2 or less or a diarylamino group having 12 or less carbon atoms is exemplified. Z ^{21 -} is Z ^11-
Represents a counter ion having the same meaning as

In the formula (V), R ³¹ , R ³² and R ³³ may be the same or different and represent a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, and an aryloxy group having 12 or less carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

In the present invention, specific examples of onium salts that can be suitably used as a radical generator include:
Paragraph number [003 of Japanese Patent Application No. 11-310623]
0] to [0033].

Also, general formulas (I) described in paragraphs [0012] to [0050] of JP-A-9-34110 are disclosed.
-Onium salts represented by formulas (IV) to (IV):
Known polymerization initiators such as the thermal polymerization initiator described in Paragraph No. [0016] of JP-A-1 (1998) are also preferably used. The radical generator used as a polymerization initiator in the present invention,
Preferably, the maximum absorption wavelength is 400 nm or less,
Further, the thickness is preferably 360 nm or less. By setting the absorption wavelength in the ultraviolet region, the image forming material can be handled under a white light.

III) Compound Having a Polymerizable Unsaturated Group The compound having a polymerizable unsaturated group used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, Preferably, it is selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. Such compounds are widely known in the industrial field, and they can be used in the present invention without any particular limitation. These are, for example, monomers, prepolymers, ie dimers,
Includes those having chemical forms such as trimers and oligomers, or mixtures thereof, and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters and amides thereof, and are preferred. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy,
A dehydration condensation product with a monofunctional or polyfunctional carboxylic acid is also preferably used.

Further, unsaturated carboxylic esters, amides and monofunctional or polyfunctional alcohols having an electrophilic substituent such as an isocyanato group or an epoxy group,
Amines, addition products with thiols, halogen groups,
Substitution products of unsaturated carboxylic esters and amides having a leaving substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines and thiols are also suitable. As another example, it is also possible to use a group of compounds in which unsaturated phosphonic acid, styrene, vinyl ether or the like is substituted for the above unsaturated carboxylic acid.

The monomers of the ester of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylates, methacrylates, itaconic esters,
Examples thereof include crotonic acid esters, isocrotonic acid esters, and maleic acid esters, and specific examples thereof are described in Japanese Patent Application No. 2000-73858 previously proposed by the present inventors, paragraphs [0089] to [0093] of the specification. Mention may be made of those described.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240 and JP-A-59-5240. 59-524
1, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Further, the above-mentioned ester monomers can be used as a mixture.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylenebis-acrylamide, methylenebis-methacrylamide, 1,6-hexamethylenebis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like. Examples of other preferred amide-based monomers include those having a cyclohexylene structure described in JP-B-54-21726.

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups per molecule, to which a hydroxyl-containing vinyl monomer represented by the following general formula (2) is added. Examples include vinyl urethane compounds containing two or more polymerizable vinyl groups.

[0108]

Embedded image

In the general formula (2), R and R ′ represent H or CH ₃ . Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and
Urethane compounds having an ethylene oxide skeleton described in JP-A-8-49860, JP-B-56-17654, JP-B-62-39417, and JP-B-62-39418 are also suitable.

Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909 and JP-A-1-105238. Can obtain a photosensitive composition having an extremely high photosensitive speed.

As another example, see JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in each publication. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Further, the Journal of the Adhesion Society of Japan vol. 20, no. 7, pages 300 to 308 (1
984) as photocurable monomers and oligomers.

Regarding these addition polymerizable compounds, what kind of structure is used, whether they are used alone or in combination,
Details of the method of use, such as the amount of addition, can be arbitrarily set in accordance with the final performance design of the light-sensitive material. For example, it is selected from the following viewpoints. From the viewpoint of the photosensitive speed, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or more functional structure is preferable. In order to increase the strength of the image area, that is, the cured film, those having three or more functional groups are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylates, methacrylates, styrene compounds, vinyl ethers) It is also effective to adjust both the photosensitivity and the intensity by using the compound (1) in combination. A compound having a large molecular weight or a compound having a high hydrophobicity is excellent in photosensitive speed and film strength, but may not be preferable in terms of developing speed and precipitation in a developing solution.

Also, the selection and use of the addition polymerization compound is important for the compatibility and dispersibility with other components (eg, binder polymer, polymerization initiator, colorant, etc.) in the photosensitive composition. Factors, such as the use of low-purity compounds,
The compatibility may be improved by using two or more kinds in combination.
In the case of a lithographic printing plate precursor, a specific structure may be selected for the purpose of improving the adhesion of a support, an overcoat layer, and the like described below. Regarding the compounding ratio of the addition polymerizable compound in the photosensitive composition, the larger the proportion, the more advantageous in sensitivity. However, if the proportion is too large, undesired phase separation may occur or the production of the photosensitive composition due to the stickiness may occur. There may be problems in the process (for example, poor production resulting from transfer of the photosensitive material components and adhesion) and problems such as precipitation from a developing solution when used as a lithographic printing plate precursor. From these viewpoints, the preferred compounding ratio is often 5 to the total components of the composition.
８０80% by weight, preferably 25-75% by weight. These may be used alone or in combination of two or more.
In addition, the method of using the addition polymerizable compound can be arbitrarily selected from the viewpoints of the degree of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface tackiness, etc. Depending on the case, a layer structure and a coating method such as undercoating and overcoating may be performed.

IV) Binder Insoluble in Water and Soluble in Alkaline Aqueous Solution In the lithographic printing plate precursor according to the invention, it is preferred to further use a binder polymer in the photosensitive layer. It is preferable to contain a linear organic high molecular polymer as the binder. Any of such “linear organic high molecular polymers” may be used. Preferably, a water-soluble or weakly alkaline water-soluble or swellable linear organic high molecular polymer that enables water development or weakly alkaline water development is selected. The linear organic high molecular polymer is selected and used not only as a film forming agent of the composition but also as a water, weakly alkaline water or organic solvent developing agent. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such a linear organic high molecular polymer include an addition polymer having a carboxylic acid group in a side chain, for example, Japanese Unexamined Patent Publication No.
Nos. 9-44615, JP-B-54-34327, JP-B-58-12577, JP-B-54-25957, JP-A-54-92723, JP-A-59-53836, and JP-A-59-71048. Those described, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, partially esterified maleic acid copolymer, and the like. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful.

In particular, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / Other addition-polymerizable vinyl monomers as needed) copolymer,
It is suitable because it has an excellent balance of film strength, sensitivity and developability.

Further, Japanese Patent Publication No. 7-12004, Japanese Patent Publication No.
JP-A-120041, JP-B-7-120042, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1-271174,
The urethane-based binder polymer containing an acid group described in Japanese Patent Application No. 10-116232 is very excellent in strength, and therefore is advantageous in terms of printing durability and low exposure suitability.
Further, a binder having an amide group described in JP-A-11-171907 is suitable because it has excellent developability and film strength.

Further, as the water-soluble linear organic polymer, polyvinyl pyrrolidone, polyethylene oxide and the like are useful. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These linear organic high molecular polymers can be incorporated in any amount in the entire composition. However, if it exceeds 90% by weight, no favorable result is obtained in view of the strength of the formed image and the like. Preferably 30 to 85
% By weight. The weight ratio of the photopolymerizable compound having an ethylenically unsaturated double bond and the linear organic high molecular polymer is preferably in the range of 1/9 to 7/3.

The binder polymer of the present invention is substantially insoluble in water and soluble in an aqueous alkali solution. For this reason, an organic solvent which is not environmentally unfavorable is not used or the amount used is extremely small as a developer.
The acid value (the acid content per gram of the polymer expressed by a chemical equivalent number) and the molecular weight of such a binder polymer are appropriately selected from the viewpoint of image strength and developability. Preferred acid values are 0.4-3. The molecular weight is Omeq / g, and the preferred molecular weight is in the range of 3,000 to 500,000, and more preferably the acid value is in the range of 0.6 to 2.0, and the molecular weight is in the range of 10,000 to 300,000.

(V) Other Components In the present invention, other components suitable for the use, the production method and the like can be appropriately added to the photosensitive layer.
Hereinafter, preferred additives will be exemplified. (V-1) Co-sensitizer The sensitivity can be further improved by using a certain additive (hereinafter referred to as a co-sensitizer). Although their mechanism of action is not clear, most are thought to be based on the following chemical processes. That is, a co-sensitizer reacts with a photoreaction initiated by a thermal polymerization initiator and various intermediate active species (radicals, cations) generated during the subsequent addition polymerization reaction to generate a new active radical. It is estimated that These are roughly (a) those that can be reduced to produce active radicals, (b) those that can be oxidized to produce active radicals, and (C) those that react with less active radicals and are more active radicals. Or acting as a chain transfer agent, but it is often unconventional as to which of these compounds an individual compound belongs to.

(A) Compound that generates an active radical upon being reduced Compound having a carbon-halogen bond: It is considered that a carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-
Triazines, trihalomethyloxadiazoles and the like can be suitably used. Compounds having a nitrogen-nitrogen bond:
It is considered that the nitrogen-nitrogen bond is reductively cleaved to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used. Compound having an oxygen-oxygen bond: It is considered that the oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides and the like are preferably used. Onium compound: a carbon-hetero bond or an oxygen-
It is thought that the nitrogen bond is cleaved to generate an active radical. Specifically, for example, diaryliodonium salts,
Triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used. Ferrocene, iron arene complexes: can generate active radicals reductively.

(B) Compound which is oxidized to form an active radical Alkyl ate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to form an active radical. Specifically, for example, triarylalkyl borates are preferably used. Alkylamine compound: It is considered that the CX bond on carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical. X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group, or the like.
Specific examples include ethanolamines, N-phenylglycines, N-trimethylsilylmethylanilines and the like. Sulfur- and tin-containing compounds: Compounds in which the nitrogen atom of the above-mentioned amines is replaced with a sulfur atom or a tin atom can generate an active radical by the same action. Compounds having an SS bond are also known to be sensitized by SS cleavage.

Α-Substituted methylcarbonyl compound: An active radical can be generated by cleavage of the bond between carbonyl and α carbon by oxidation. In addition, those obtained by converting carbonyl to oxime ether also show the same action. In particular,
2-alkyl-1- [4- (alkylthio) phenyl]
-2-Morpholinopronones-1 and oxime ethers obtained by reacting these with hydroxyamines and then etherifying N-OH. Sulfinates: Active radicals can be generated reductively. Specific examples include sodium arylsulfin and the like.

(C) Compounds which react with radicals to convert them into highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, GeH in the molecule are used. These can generate a radical by donating hydrogen to a low-activity radical species, or can generate a radical by being oxidized and then deprotonated. Specific examples include 2-mercaptobenzimidazoles.

Many more specific examples of these co-sensitizers are described in, for example, JP-A-9-236913 as additives for the purpose of improving sensitivity. Can also be applied. These co-sensitizers can be used alone or in combination of two or more. The amount is suitably in the range of 0.05 to 100 parts by weight, preferably 1 to 80 parts by weight, more preferably 3 to 50 parts by weight, per 100 parts by weight of the compound having an ethylenically unsaturated double bond.

(V-2) Polymerization Inhibitor In the present invention, in addition to the above basic components, there is no need for a compound having an ethylenically unsaturated double bond which can be polymerized during the production or storage of the photosensitive layer coating solution. It is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent a thermal polymerization. Suitable thermal polymerization inhibitors include hydroquinone, p
-Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4- Methyl-
6-t-butylphenol), cerium N-nitrosophenylhydroxyamine, and the like. The amount of the thermal polymerization inhibitor added is about 0.01 to the weight of the whole composition.
% By weight to about 5% by weight is preferred. In addition, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition by oxygen, and when used as a lithographic printing plate precursor, after application to a support or the like, During the drying process, it may be unevenly distributed on the surface of the photosensitive layer. The amount of the higher fatty acid derivative to be added ranges from about 0.5% by weight to about 10% by weight of the total composition.
% By weight is preferred.

(V-3) Colorant, etc. Further, a dye or pigment may be added for the purpose of coloring the photosensitive layer in the lithographic printing plate precursor according to the invention.
As a result, it is possible to improve the so-called plate inspection, such as the visibility of the printing plate after plate making and the suitability for an image density measuring device. As a coloring agent, a pigment is particularly preferable because many dyes lower the sensitivity of the photopolymerizable photosensitive layer. Specific examples include pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide, and dyes such as ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The amount of dyes and pigments added is preferably from about 0.5% to about 5% by weight of the total composition.

(V-4) Other Additives In order to improve the physical properties of the cured film, the photosensitive layer according to the present invention may contain an inorganic filler, other plasticizers, and an ink deposit on the surface of the photosensitive layer. Known additives such as a sensitizer that can be improved may be added.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin and the like. A binder was used. In this case, it can be added in an amount of 10% by weight or less based on the total weight of the compound having an ethylenically unsaturated double bond and the binder.

Further, a UV initiator, a thermal crosslinking agent and the like can be added to enhance the effect of heating and exposure after development for the purpose of improving the film strength (printing durability) described later. In addition, it is also possible to use an additive for improving the adhesion between the photosensitive layer and the support and for improving the development and removal of the unexposed photosensitive layer. For example, by adding or undercoating a compound having a diazonium structure or a compound having a relatively strong interaction with the substrate, such as a phosphone compound, the adhesion can be improved and the printing durability can be increased. Addition of an acid or a hydrophilic polymer such as polysulfonic acid or undercoating improves the developability of the non-image area and improves the stainability.

In forming a photosensitive layer of a lithographic printing plate precursor, it is general to form a film by dissolving various components contained in the photosensitive layer in various organic solvents, coating the solution on an intermediate layer, and drying. It is. As the solvent used here, acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, methyl lactic acid And ethyl. These solvents can be used alone or as a mixture. The appropriate concentration of the solid content in the coating solution is 2 to 50% by weight.

The amount of the photosensitive layer to be applied is desirably selected in accordance with the intended use in consideration of the sensitivity, developability of the photosensitive layer, and the strength and printing durability of the exposed film. When the coating amount is too small, the printing durability becomes insufficient. On the other hand, if the amount is too large, the sensitivity is lowered, and it takes a long time for exposure, and a longer time is required for the developing process, which is not preferable. The coating amount of the lithographic printing plate precursor according to the invention is generally about 0. range of lg / m ² ~ about 10 g / m ² are suitable. More preferably, it is 0.5 to 5 g / m ² .

[Protective Layer] The lithographic printing plate precursor according to the invention is usually provided with a protective layer on the photopolymerizable composition layer, since the exposure is usually performed in the air. The protective layer is
The present invention prevents low-molecular compounds such as oxygen and basic substances present in the atmosphere that inhibit an image forming reaction caused by exposure in the photosensitive layer from being mixed into the photosensitive layer, thereby enabling exposure in the atmosphere.
Therefore, the desired properties of such a protective layer is that the permeability of low molecular compounds such as oxygen is low, and further, the transparency of light used for exposure is good, and the adhesion with the photosensitive layer is excellent.
In addition, it is desirable that it can be easily removed in a developing step after exposure.

Such a device for the protective layer has been conventionally devised, and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used, and specifically, polyvinyl alcohol, polyvinylpyrrolidone, acidic celluloses, gelatin, gum arabic, and polystyrene. Although water-soluble polymers such as acrylic acid are known, use of polyvinyl alcohol as a main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, or an acetal as long as it contains an unsubstituted vinyl alcohol unit for obtaining necessary oxygen barrier properties and water solubility. Similarly, a part thereof may have another copolymer component.

Specific examples of polyvinyl alcohol include 7
1-100% hydrolyzed, molecular weight 300-240
A range of 0 can be given. Specifically, Kuraray's PVA-105, PVA-110, PVA
A-117, PVA-117H, PVA-120, PV
A-124, PVA-124H, PVA-CS, PVA
-CST, PVA-HC, PVA-203, PVA-2
04, PVA-205, PVA-210, PVA-21
7, PVA-220, PVA-224, PVA-217
EE, PVA-217E, PVA-220E, PVA-
224E, PVA-405, PVA-420, PVA-
613 and L-8.

The components of the protective layer (selection of PVA, use of additives), the amount of coating, and the like are selected in consideration of fogging properties, adhesion, and scratch resistance in addition to oxygen blocking properties and development removability. Generally, the higher the hydrolysis rate of the PVA used (the higher the content of unsubstituted vinyl alcohol units in the protective layer) and the thicker the film thickness, the higher the oxygen barrier properties, which is advantageous in terms of sensitivity. However, when the oxygen barrier property is extremely increased, there arises a problem that an unnecessary polymerization reaction occurs at the time of production or raw storage, and that unnecessary fogging and thickening of an image occur at the time of image exposure. Further, the adhesion to the image area and the scratch resistance are also extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on a lipophilic polymer layer, film peeling due to insufficient adhesive force tends to occur, and the peeled portion causes defects such as poor film curing due to inhibition of oxygen polymerization.

On the other hand, various proposals have been made to improve the adhesiveness between these two layers. For example, US Patent No. 2
No. 92,501 and U.S. Pat. No. 44,563, an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer or the like is mixed in a hydrophilic polymer mainly composed of polyvinyl alcohol in an amount of 20 to 60% by weight. It is described that sufficient adhesiveness can be obtained by laminating on a polymer layer. Any of these known techniques can be applied to the protective layer in the present invention. Regarding the method of applying such a protective layer,
For example, U.S. Pat. No. 3,458,311;
No. 49729.

Further, other functions can be imparted to the protective layer. For example, it excels in the transmission of light of the wavelength used for exposure,
By adding a colorant (a water-soluble dye or the like) capable of efficiently absorbing light having a wavelength not related to exposure, the suitability for safelight can be further increased without lowering the sensitivity.

[Exposure] As described above, the planographic printing plate precursor of the invention can be prepared. This lithographic printing plate precursor is image-exposed by a solid-state laser and a semiconductor laser that emit infrared light having a wavelength of 760 nm to 1200 nm. In the present invention, the developing treatment may be performed immediately after the laser irradiation, or the heat treatment may be performed between the laser irradiation step and the developing step. The conditions of the heat treatment are 80 ° C to 15 ° C.
It is preferable to carry out for 10 seconds to 5 minutes within the range of 0 ° C. By this heat treatment, the laser energy required for recording at the time of laser irradiation can be reduced.

[Development] In making the lithographic printing plate precursor according to the invention, usually, after image exposure, an unexposed portion of the photosensitive layer is removed with a developing solution to obtain an image. Preferred developers for use in preparing a lithographic printing plate include JP-B-57-74.
No. 27, such as sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, and tertiary phosphorus. Ammonium acid,
Aqueous solutions of inorganic alkali agents such as ammonium diphosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia and organic alkali agents such as monoethanolamine or diethanolamine are suitable. The alkaline solution is added so that the concentration of the alkaline solution is 0.1 to 10% by weight, preferably 0.5 to 5% by weight.

Also, such an alkaline aqueous solution includes:
If necessary, a small amount of a surfactant or an organic solvent such as benzyl alcohol, 2-phenoxyethanol or 2-butoxyethanol can be contained. For example, those described in U.S. Pat. Nos. 3,375,171 and 3,615,480 can be mentioned. Further, Japanese Unexamined Patent Publication No.
Nos. 0-26601, 58-54341, Tokubo Sho56
The developers described in JP-A-39464 and JP-A-56-42860 are also excellent.

The lithographic printing plate obtained as described above can be subjected to a printing step after coating with a desensitizing gum if desired. Is subjected to a burning process. When burning a lithographic printing plate, before burning,
No. 2518, No. 55-28062, JP-A-62-3
It is preferable to treat with a surface-regulating liquid as described in JP-A Nos. 1859 and 61-159655. As a method, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied on a lithographic printing plate, or a method in which the printing plate is immersed in a vat filled with the surface conditioning solution and applied, Application by an automatic coater or the like is applied. Further, it is more preferable to make the amount of the coating uniform with a squeegee or a squeegee roller after the coating.

The burned lithographic printing plate can be subjected to a conventional treatment such as washing with water or gumming, if necessary. When a liquid is used, a so-called desensitizing treatment such as gumming can be omitted. The lithographic printing plate obtained by such a process is set on an offset printing machine or the like and used for printing a large number of sheets.

[0143]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Synthesis of Polymer Used for Intermediate Layer> (Synthesis Example 1, Method 1) In a 200-ml three-necked flask equipped with a stirring rod and a stirring blade, a reflux condenser, and a thermometer, 2-methoxy was used as a reaction solvent. Ethanol 70
g, 21.3 g of (4-vinylbenzyl) triethylammonium chloride, and 8.3 g of 4-vinylbenzoic acid
And stirred at 50 ° C. for 30 minutes under a nitrogen stream to obtain a homogeneous solution. Thereto was added 1.04 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator, and the mixture was stirred at 80 ° C. for 7 hours to perform polymerization. This solution was charged with 500 ml of ethyl acetate, and the resulting precipitate was dried under vacuum to remove a polymer having a cationic group and a reactive group into 2 parts.
9.5 g were obtained. The acid value of this polymer is 1.85 meq
/ G.

150 ml of methanol as a reaction solvent and 9.5 g of the obtained polymer having a cationic group and a reactive group were added to three 200 ml flasks equipped with a stirring rod and a stirring blade, a reflux condenser, and a thermometer. Dissolved. 1.3 g of glycidyl methacrylate was added thereto,
The mixture was refluxed for 5 hours. This solution is diluted with ethyl acetate 1000m
The resulting precipitate was dried under vacuum to obtain 10.1 g of a polymer (P-1) having a cationic group and a radical polymerization reactive group in the present invention.
The acid value of this polymer was 0.79 meq / g.

(Synthesis Example 2, Method 1) 200 ml provided with a stirring rod and stirring blade, a reflux condenser, and a thermometer
150 ml of dimethyl sulfoxide as a reaction solvent and 9.5 g of a polymer having a cationic group and a reactive group obtained in Synthesis Example 1 were added and dissolved in the three flasks. Thereto, 1.4 g of 2- (methacryloyloxy) ethyl isocyanate and 3 drops of di-n-butyltin dilaurate were added, and the mixture was heated and stirred at 50 ° C. for 5 hours. This solution was poured into 1,000 ml of ethyl acetate, and the resulting precipitate was dried in vacuo to obtain the polymer (P-2) having a cationic group and a radical polymerization reactive group in the present invention.
3 g were obtained. The acid value of this polymer was 0.84 meq / g.

(Synthesis Example 3, Method 2) 200 ml provided with a stirring rod and stirring blade, a reflux condenser, and a thermometer
In three flasks, methanol 50 was used as the reaction solvent.
g, poly (4-vinylpyridine) (weight average molecular weight 2)
(0000) was dissolved. There 4-
6.1 g of (chloromethyl) styrene was added, and the mixture was refluxed under heating for 8 hours. This solution was poured into 8000 ml of ethyl acetate, and the obtained precipitate was dried under vacuum to obtain 15.4 g of a polymer (P-3) having a cationic group and a radical polymerization reactive group in the present invention.

(Synthesis Example 4, Method -2) 200 ml provided with a stirring rod and stirring blade, a reflux condenser, and a thermometer
In three flasks, methanol 50 was used as the reaction solvent.
g, poly [(dimethylamino) ethyl methacrylate]
(Weight average molecular weight: 78,000) 15.7 g was added and dissolved. Then add 12.0 g of propargyl bromide,
The mixture was heated under reflux for 8 hours. This solution was treated with 8000 m of ethyl acetate.
The resulting precipitate was dried under vacuum to obtain 21.3 g of a polymer (P-4) having a cationic group and a radical polymerization reactive group in the present invention.

(Synthesis Example 5, Method -3) 200 ml provided with a stirring rod and stirring blade, a reflux condenser, and a thermometer
80m3 of methanol as a reaction solvent
l, 20 ml of acetone and 7.6 g of poly (chloromethylstyrene) (weight average molecular weight 24,000) were added and dissolved. 1.6 g of 2- (dimethylamino) ethyl methacrylate was added and heated at 40 ° C. for 3 hours. There N
-6.6 g of n-butylamine, and further added at 40 ° C.
Heated for hours. This solution was poured into 500 ml of ethyl acetate, and the obtained precipitate was dried under vacuum to obtain 12.4 g of a polymer (P-5) having a cationic group and a radical polymerization reactive group in the present invention.

(Synthesis Example 6, Method -4) 200 ml provided with a stirring rod and stirring blade, a reflux condenser, and a thermometer
90 g of 2-methoxyethanol as a reaction solvent and [2- (methacryloyloxy) ethyl]
Trimethylammonium methyl sulfate (80% by weight aqueous solution of aqueous solution) 17.7 g, allyl methacrylate 3.8
g, and 1.7 g of methacrylic acid, and under a nitrogen stream,
The mixture was stirred at 50 ° C. for 30 minutes to obtain a homogeneous solution. Thereto was added 1.24 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator, and the mixture was stirred at 80 ° C. for 8 hours to perform polymerization. This solution was poured into 1000 ml of ethyl acetate, and the obtained precipitate was dried in vacuo to obtain 19.6 g of a polymer (P-6) having a cationic group and a radical polymerization reactive group in the present invention. The acid value of this polymer was 0.96 meq / g.

(Synthesis Example 7, Method -5) 200 ml equipped with a stirring rod and stirring blade, a reflux condenser, and a thermometer
Into three flasks, 50 g of N, N-dimethylacetamide as a reaction solvent and (4-vinylbenzyl) triallylammonium hexafluorophosphate 1
2.0 g was stirred at 50 ° C. for 30 minutes to obtain a homogeneous solution. Thereto was added 0.15 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator.
The polymerization was carried out by stirring for an hour. 1000 ml of this solution in water
And the resulting precipitate is dried under vacuum,
10.3 g of a polymer (P-7) having a cationic group and a radical polymerization reactive group in the present invention was obtained.

(Examples 1 to 17, Comparative Examples 1 to 4) A lithographic printing plate precursor was prepared in the following procedure. <Preparation of support> An aluminum plate (material 1050) having a thickness of 0.3 mm was washed with trichloroethylene and degreased, and then the surface was grained using a nylon brush and a 400 mesh Pumice water suspension. ,
After washing with water, it was further immersed in 20% nitric acid for 20 seconds and washed with water.
At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was subjected to current density of 1 using 7% sulfuric acid as an electrolyte.
After providing a direct current electrode oxidized film of 3 g / m ² at 5A / dm ^2,
After washing with water and drying, a substrate (A) was prepared. The substrate (A) was treated with a 2% by weight aqueous solution of sodium silicate at 25 ° C. for 15 seconds, and washed with water to form a substrate (B).

<Formation of Intermediate Layer> An intermediate layer coating solution having the following composition (A) or (B) was prepared on the hydrophilized surface of the support (substrate (B)) obtained above. After coating, the coating was dried at 80 ° C. for 15 seconds to form an intermediate layer.
As the polymer having a radical polymerization reactive group, the following exemplified monomers T-1 to T-5 were used in addition to the polymers P-1 to P-7 obtained in the above Synthesis Examples. The coating amount after drying was 15 mg / m ² . The substrates (A) and (B) on which the intermediate layer was not formed were used as supports for Comparative Examples 1 and 2. Further, in place of the polymer having a radical polymerization reactive group in the following intermediate layer coating solution, the following repeating unit R- having no radical polymerization reactive group
A substrate on which an intermediate layer was formed using a polymer containing the polymer having 1, R-2 was used as a lithographic printing plate precursor support in Comparative Examples 3 and 4.

(Intermediate Layer Coating Solution A) Polymer having a radical polymerization reactive group (compounds shown in Table 1) 0.3 g methanol 100 g water 1 g

(Intermediate Layer Coating Solution B) Polymer having a radical polymerization reactive group (compound shown in Table 1) 0.3 g methanol 70 g water 70 g

<Coating of photosensitive layer> A coating solution of a photosensitive layer having the following composition was prepared on a support provided with the above-mentioned intermediate layer, and coated so that the coating amount after drying was 2.0 g / m ^2. After drying at 100 ° C. for 2 minutes to form a photosensitive layer, a lithographic printing plate precursor was obtained.

(Coating solution for photosensitive layer) Addition polymerizable compound (compound shown in Table 1) 1.5 g Binder (compound shown in Table 1) 2.0 g Infrared absorber (compound shown in Table 1) 0.1 g・ Polymerization initiator (compounds listed in Table 1) 0.2 g ・ Fluorine nonionic surfactant (Megafac F-177, manufactured by Dainippon Ink and Chemicals, Inc.) 0.02 g ・ Victoria Pure Blue 0.04 g ・ Methyl ethyl ketone 10 g ・ Methanol 7 g ・ 2-Methoxy-1-propanol 10 g

[0158]

[Table 1]

[0159]

Embedded image

(Addition polymerizable compounds in Table 1) (M-1) pentaerythritol tetraacrylate (M-2) glycerin dimethacrylate hexamethylene diisocyanate urethane prepolymer

(Binder polymer in Table 1) (B-1) Allyl methacrylate / methacrylic acid / N-isopropylamide copolymer (copolymerization molar ratio: 67/13/20) Acid value (actually measured by NaOH titration) 1 .15 meq / g Polymerization average molecular weight 130,000 (B-2) Allyl methacrylate / methacrylic acid copolymer (copolymerization molar ratio: 83/17) Acid value (actually measured by NaOH titration) 1.55 meq / g Polymerization average molecular weight 12. 50,000 (B-3) Polyurethane resin which is a condensate of the following diisocyanate and diol: (a) 4,4'-diphenylmethane diisocyanate (b) hexamethylene diisocyanate (c) polypropylene glycol (weight average molecular weight: 10
00) (d) 2,2-bis (hydroxymethyl) propionic acid ((a) / (b) / (c) / (d) copolymer molar ratio: 40/10/1)
5/35) Acid value (actually measured by NaOH titration) 1.05 meq / g Polymerization average molecular weight 45,000

<Exposure and Development> The obtained lithographic printing plate precursor was output at a power of 500 mW, a wavelength of 830 nm, and a beam diameter of 17 μm.
After exposure at a main scanning speed of 5 m / sec using a (l / e ² ) semiconductor laser, a DN3C developer or a DP-4 developer and a rinsing solution FR-3 (1:
7) Automatic developing machine (Fuji Photo Film Co., Ltd.)
(Manufactured by PS Processor 900VR) and the following evaluation was performed. Table 1 also shows which developing solution was used in the developing process. The evaluation results are shown in Table 2 below.

<Printing durability test> R201 manufactured by Roland was used as a printing machine, and G was manufactured by Dainippon Ink and Chemicals, Inc.
EOS-G (N) was used. The printed matter in the solid image area was observed, and the printing durability was examined based on the number of sheets at which the image began to fade. It was represented by a relative ratio where the numerical value (number of sheets) in Comparative Example 1 was 100. The greater the number, the better the printing durability.

<Adhesion Test> Adhesion was measured by using R201 manufactured by Roland as a printing machine, and using GEOS-G (N) manufactured by Dainippon Ink Co., Ltd. as an ink. 5 from the start of printing
On the 000th sheet, PS plate cleaner CL-2 manufactured by Fuji Photo Film Co., Ltd. was infiltrated into a printing sponge, halftone dots were wiped off, and the ink on the plate surface was washed. Then 10,0
The printing of 00 sheets was performed, and the presence or absence of halftone dot skipping in the printed matter was visually observed. ○: No skipping ×: Skipping

[0165]

[Table 2]

As is evident from Table 2, the lithographic printing plate precursors of the present invention were all excellent in printing durability, no plate skipping was observed, and the halftone dot adhesion was good. .
On the other hand, the lithographic printing plate precursor of Comparative Example using a polymer having no radical polymerization reactive group has the same photosensitive layer, but has lower printing durability than those of Examples, and a halftone plate Flying was observed, and it was found that the effect of improving adhesion was insufficient.

(Examples 18 to 34, Comparative Examples 5 to 8) In the lithographic printing plate precursors of Examples 1 to 17 and Comparative Examples 1 to 4 used above, polyvinyl alcohol (a saponification degree of 98 mol) was formed on the photosensitive layer. %, A degree of polymerization of 550) was applied to a dry coating weight of 2 g / m ² and dried at 100 ° C. for 2 minutes to obtain a protective layer.
To 34 and the lithographic printing plate precursors of Comparative Examples 5 to 8 were obtained. The results of evaluation in the same manner as in Example 1 are shown in Table 3 below.

[0168]

[Table 3]

As is clear from Table 3, in the case where the protective layer was provided on the surface, the printing durability was improved as compared with the case without the protective layer because the polymerization inhibition by oxygen and the like was suppressed. As a whole, the lithographic printing plate precursors of the present invention were all excellent in printing durability, in which no plate skipping was observed, and adhesion of halftone dots was good, but a polymer having no radical polymerization reactive group. The lithographic printing plate precursor of the comparative example using, like the one without the protective layer, has lower printing durability than that of the example,
Halftone dot skipping was observed, indicating that the effect of improving adhesion was insufficient.

[0170]

The negative type lithographic printing plate precursor according to the present invention can be written with an infrared laser, has excellent adhesion between the support and the photosensitive layer in the image area, and reproduces images such as halftone dots and fine lines. This has the effect of excelling in printability and printing durability.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuto Kunida 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. (Reference) 2H025 AA04 AA12 AA14 AB03 AC08 AD01 BC13 CC11 DA35 DA36 2H096 AA06 BA05 CA03 CA05 EA04 EA23 2H114 AA04 AA22 AA23 AA24 AA28 AA29 AA30 BA01 BA10 DA52 EA01 EA03

Claims (2)

[Claims] An intermediate layer containing a compound having a radical polymerization reactive group on a support subjected to a hydrophilic treatment, and
A heat mode comprising: a photosensitive layer containing I) an infrared absorber, II) a polymerization initiator, and III) a compound having a polymerizable unsaturated group, and recordable by an infrared laser. The corresponding lithographic printing original plate. 2. The lithographic printing plate precursor according to claim 1, wherein the compound having a radical polymerization reactive group further has a cationic group.