JPH11301130A - Material for lithographic printing plate and method for engraving lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material for a lithographic printing plate adopting a drying treatment, capable of directly engraving it according to an electric signal from a computer and having an excellent ink coating stability of an image part without scumming a non-image part and a method for engraving the printing plate for engraving it by using the material without the necessity of a releasing step. SOLUTION: The material for a lithographic printing plate comprises a recording layer for lowering a hydrophilic property by a heat and a hydrophilic layer having a maximum absorption in an infrared ray region sequentially formed on a support. The hydrophilic layer has the maximum absorption in a wavelength of 700 to 1,200 nm and a transmission density of the maximum absorption of 1.0 or more, and a dry film thickness of the hydrophilic layer is 1.0 μm or less.

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 material and a method for making a lithographic printing plate using the lithographic printing plate material. Technology that does not need to be processed.

[0002]

2. Description of the Related Art A conventional plate making system is very troublesome in that a negative or positive film is prepared from under the plate, baked on a PS plate coated with a photosensitive polymer, and then developed to complete the plate making. there were. In recent years, digitization of plate making has rapidly progressed, and means for directly linking an electric signal from a computer to plate making have been proposed.

Specifically, a method of converting an electric signal from a computer into a laser beam, printing the photosensitive polymer on a photosensitive polymer, and then developing the plate to make a plate is generally used, but a developing step is still required. Ink jet recording and electrophotography have been proposed as methods for directly applying an image forming material onto a plate. However, it has drawbacks in the reproduction stability and resolution of the image part.

As means for achieving plate reproduction without performing development operations while achieving reproduction stability and high resolution of a printed image, various types of direct plate making using a thermal head or laser light have been proposed. For example, JP-A-49-118
No. 501 discloses a method in which a surface of an object containing a lipophilic resin is subjected to a chemical conversion treatment to form a lipophilic layer, and the lipophilic layer is selectively removed by laser light to form an image portion. However, this method consumes a lot of energy,
The plate making speed is also slow, and the problem is that the resolution is low due to the generation of polymer debris and cinders.

JP-A-51-63704 discloses that when a plate material covered with a hydrophilic polymer layer made of a non-photosensitive compound is irradiated with a laser beam, the irradiated portion is cured and becomes hydrophobic or lipophilic. There is disclosed a technique of changing the state to absorb light. In this method, it is difficult to harden and uniformly change the image area, and there is a drawback in that the water-soluble polymer constituting the non-image area elutes during printing, and printing stains are likely to occur.

Japanese Patent Application Laid-Open No. 3-108588 proposes a method in which a heat-melted substance microencapsulated with a pigment is applied to a support, and the heating section is changed to lipophilic to deposit the ink. The disadvantage is that the particle size of the microcapsules is large, the resolution of the resulting printed matter is basically low, and the lipophilic hot-melt substance easily adheres to the support through the breakage of the capsules and the walls on the plate and easily causes printing stains. Have.

Japanese Patent Publication No. Hei 6-71787 discloses that a non-image area is formed by introducing a sulfonic acid group into the surface of a plate material made of a lipophilic polymer, and the surface is irradiated with a laser beam having a specific energy density. A method for forming an image portion by selectively removing is disclosed. However, there is a disadvantage that printing stains are likely to occur due to the partial exposure of the lipophilic polymer layer at the lower part of the surface treated with the sulfonic acid group.

JP-A-7-1849 and JP-A-7-1850 comprise a microcapsulated hydrophilic layer containing a lipophilic component converted into an image area by heat and a hydrophilic binder polymer, and a support, A heat-sensitive lithographic printing plate has been proposed in which a hydrophilic binder polymer is three-dimensionally cross-linked and is devised to chemically bond to the lipophilic component in the microcapsule after the capsule is broken. However, the particle size of the microcapsules is large, the resolution of the printed matter obtained is basically low, the adhesion between the hydrophilic binder polymer and the support is basically insufficient, and the lipophilic component and the hydrophilic binder polymer Since the boundary between them is not clear, they still have print smearing and reduced resolution.

As a solution to this problem, Japanese Patent Application Laid-Open No. Hei 9-127683 proposes a lithographic printing plate in which a resin particle layer which can be made lipophilic by heat is formed on the surface of a hydrophilic substrate. This is a technology that heats the image and converts the hydrophilic part to lipophilic.
If the hydrophilicity before image formation is increased, the lipophilicity of the obtained lipophilic image is not sufficient. Conversely, if the hydrophilicity before image formation is suppressed, there is a problem that stain is likely to occur during printing. Also, when actually used, a peelable drying prevention film is formed on the resin particle layer in order to enhance the storage stability of the plate, and the printing step requires a peeling step, so that the operation is troublesome. Is concerned.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to enable direct plate making of an electric signal from a computer and to have excellent ink deposition stability in an image portion. Another object of the present invention is to provide a lithographic printing plate material which does not have a print stain on a non-image portion and employs a dry process.
Another object of the present invention is to provide a method of making a lithographic printing plate that can make a plate using the lithographic printing plate material without requiring a peeling step.

[0011]

The object of the present invention has been attained by the following constitutions.

(1) A lithographic printing plate material comprising a support, in which a recording layer whose hydrophilicity is reduced by heat and a hydrophilic layer having a maximum absorption in an infrared region are formed in this order.

In a preferred embodiment of the lithographic printing plate material, a) the hydrophilic layer has a maximum absorption at a wavelength of 700 nm or more and 1200 nm or less, and a transmission density at the maximum absorption is 1.0 or more; b) ) The dry thickness of the hydrophilic layer is 1.0 µm or less, c) The hydrogen bond component (H) of the surface energy γ of the hydrophilic layer is 20 or more, and the cohesive force component of the surface energy γ (D) is 40
D) center line average roughness R of the recording layer side surface
a is 0.5 or more.

(2) 1 w / cm of the lithographic printing plate material
A plate making method for a lithographic printing plate, comprising irradiating ^two or more laser beams imagewise to remove a hydrophilic layer in an irradiated portion and reduce the hydrophilicity of a recording layer in the irradiated portion.

Hereinafter, the present invention will be described in detail.

A recording layer (hereinafter simply referred to as a recording layer) of the lithographic printing plate material of the present invention, whose hydrophilicity is reduced by heat;
The hydrophilic layer having a maximum absorption in the infrared region (hereinafter simply referred to as a hydrophilic layer) contains a hydrophilic resin or the like as a hydrophilic binder required for forming both layers.

First, the hydrophilic resin used as the hydrophilic binder will be described.

The hydrophilic resin has a group capable of forming a chemical bond by reacting with a crosslinking agent. These groups include, for example, a hydroxyl group, a carboxyl group, (secondary or tertiary)
Group) a group having an amine, an amino group, an amide group, a carbamoyl group, a sulfonic acid group, a phosphonic acid group, and a mercapto group. Among them, preferred groups are a hydroxyl group, a carboxyl group, a group having a (secondary or tertiary) amine, and an amino group.

Examples of these hydrophilic resins include polyvinyl alcohol, polysaccharide, polyvinylpyrrolidone, polyethylene glycol, gelatin, glue, casein, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, hydroxyethylstarch, saccharose octaacetate, ammonium alginate, and the like. Examples include sodium alginate, polyvinylamine, polyallylamine, polystyrenesulfonic acid, polyacrylic acid, water-soluble polyamide, and maleic anhydride copolymer.

Among them, preferred hydrophilic resins are gelatin,
Polyvinyl alcohol and carboxymethyl cellulose, and the most preferably used hydrophilic resins are gelatin and polyvinyl alcohol.

Hereinafter, gelatin, polyvinyl alcohol and carboxymethyl cellulose which are preferably used in the present invention will be described.

Examples of the polyvinyl alcohol include polyvinyl alcohol having various degrees of polymerization, copolymerized polyvinyl alcohol, and anion-modified polyvinyl alcohol modified with an anion such as a carboxyl group or a sulfo group and containing at least 50 mol% of a polyvinyl alcohol skeleton. Cation-modified polyvinyl alcohol modified with a cation such as an amino group or an ammonium group, silanol-modified polyvinyl alcohol, alkoxyl-modified polyvinyl alcohol,
Epoxy-modified polyvinyl alcohol, random copolymers such as thiol-modified polyvinyl alcohol; anion-modified, cation-modified, thiol-modified, silanol-modified, alkoxyl-modified and epoxy-modified such as polyvinyl alcohol, acrylamide, Block copolymerized polyvinyl alcohol into which a water-soluble monomer such as acrylic acid is introduced, graft copolymerized polyvinyl alcohol in which a silanol group or the like is grafted, and further,
Copolymerized polyvinyl alcohol into which a reactive group such as (—COCH ₂ COCH ₃ ) is introduced is used.

The polyvinyl alcohol preferably has a saponification degree of 70 mol% or more, more preferably 85 mol% or more, and particularly preferably 90% or more. Polyvinyl alcohol having a high degree of saponification is preferable because the crystallinity changes by heat treatment and water resistance can be imparted.

In the copolymerized polyvinyl alcohol, the following monomers can be used as the copolymerized monomer.

(1) Monomers having an aromatic hydroxyl group: for example, o-hydroxystyrene, p-hydroxystyrene, m-hydroxystyrene, o-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate,
m-hydroxyphenyl acrylate and the like.

(2) Monomers having an aliphatic hydroxyl group: for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, N-methylol methacrylamide, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 5-hydroxypentyl methacrylate, 6
-Hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, N- (2-hydroxyethyl)
Acrylamide, N- (2-hydroxyethyl) methacrylamide, hydroxyethyl vinyl ether and the like.

(3) Monomers having an aminosulfonyl group: for example, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate,
m-aminosulfonylphenyl acrylate, p-aminophenyl acrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like.

(4) Monomers having a sulfonamide group: for example, N- (p-toluenesulfonyl) acrylamide, N- (p-toluenesulfonyl) methacrylamide and the like. (5) α, β-unsaturated carboxylic acids:
Acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the like.

(6) Substituted or unsubstituted alkyl acrylates: for example, methyl acrylate, ethyl acrylate,
Propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, benzyl acrylate, cyclohexyl acrylate, acrylic acid -2-chloroethyl, N, N-dimethylaminoethyl acrylate, glycidyl acrylate and the like.

(7) Substituted or unsubstituted alkyl methacrylates: for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, methacrylic acid Nonyl, decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, 2-chloroethyl methacrylate, N, N-dimethylaminoethyl methacrylate, glycidyl methacrylate and the like.

(8) Acrylamide or methacrylamide: for example, acrylamide, methacrylamide, N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N -Phenylacrylamide, N-
(4-hydroxyphenyl) acrylamide, N- (4
-Hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide and the like.

(9) Monomers containing a fluorinated alkyl group: for example, trifluoroethyl acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, heptadecafluoro Decyl methacrylate, N-butyl-N- (2-acryloxyethyl) heptadecafluorooctylsulfonamide and the like.

(10) Vinyl ethers: for example, ethyl vinyl ether, 2-chloroethyl vinyl ether,
Propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ethers.

(11) Vinyl esters: for example, vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate and the like.

(12) Styrenes: for example, styrene,
Methylstyrene, chloromethylstyrene and the like.

(13) Vinyl ketones: for example, methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone and the like.

(14) Olefins: for example, ethylene, propylene, isobutylene, butadiene, isoprene and the like.

(15) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine and the like.

(16) Monomers having a cyano group: for example, acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile,
Cyanoethyl acrylate, o-cyanostyrene, m-
Cyanostyrene, p-cyanostyrene and the like.

(17) Monomer having amino group: for example, N, N-diethylaminoethyl methacrylate,
N, N-dimethylaminoethyl acrylate, N, N-
Dimethylaminoethyl methacrylate, polybutadiene urethane acrylate, N, N-dimethylaminopropylacrylamide, N, N-dimethylacrylamide,
Acryloylmorpholine, N-isopropylacrylamide, N, N-diethylacrylamide and the like.

As the polyvinyl alcohol, a polyvinyl alcohol into which a reactive group has been introduced and a polyvinyl alcohol into which an anionic group has been introduced are preferable, and among them, a polyvinyl alcohol having a reactive group introduced is preferable. Examples of the reactive group include a silanol group, an acetoacetyl group, a thiol group, and an epoxy group. Among these, particularly preferred reactive groups are a silanol group, an acetoacetyl group, and a thiol group.

The above polyvinyl alcohols may be used alone or as a mixture of two or more.

When polyvinyl alcohol is used,
The above-mentioned polyvinyl alcohol may be used as a main component, and another polymer or a release agent may be used alone or in combination of two or more types. Further, a polymer and a release agent may be used in combination of two or more types.

Specific examples of the polymer include natural polymers such as starch, processed starch, casein, glue, gelatin, gum arabic, sodium alginate, and pectin;
Semi-synthetic polymers such as carboxymethylcellulose, methylcellulose and viscose; synthetic polymers such as polyacrylamide, polyethyleneimine, sodium polyacrylate, polyethylene dioxide and polyvinylpyrrolidone;
The compounds described in JP-A-4-176688 are exemplified. Specific examples of the release agent include, for example, JP-A-4-186.
The compound described in No. 354 can be used as appropriate.

Further, compounds such as an antistatic agent and a surfactant may be mixed in order to improve the physical properties of the polyvinyl alcohol.
The compounds described in No. 4442 can be used as appropriate, and they can be used alone or in combination of two or more.

When polyvinyl alcohol is used, the thickness of the heat-sensitive layer is preferably 30 μm or less, more preferably 0.01 to 3 μm.

As the gelatin, an alkali method gelatin,
Acidic gelatin, denatured gelatin (for example,
No. 4854, No. 40-12237, British Patent 2,52
And the like can be used alone or in combination of two or more. For example, acid-treated gelatin may be used in addition to lime-treated gelatin, and gelatin hydrolyzate, Bull. Soc. Sc
i. Photo. Japan. No. 16. P30 (1
966) can also be used.

As carboxymethylcellulose, carboxymethylcellulose and its salts, for example, sodium salt, calcium salt, potassium salt, aluminum salt,
Examples thereof include a magnesium salt and an ammonium salt. Among these, carboxymethyl cellulose, carboxymethyl cellulose sodium salt, and carboxymethyl cellulose ammonium salt are preferable. Among them, carboxymethylcellulose ammonium salts are particularly preferable. When these are used, they are water-soluble, but are preferable because they have a feature that their solubility in water is reduced by coating and drying on a support.

The hydrophilic resin is used in an amount of 10 to 98% by weight in the heat-sensitive layer.
Is preferably used. 10 hydrophilic resins
When the amount is less than the weight percentage, the strength of the film is insufficient, and the reaction rate is apt to be reduced due to insufficient crosslinking point. Also, 98
If the amount is more than 10% by weight, the reaction rate tends to decrease due to an insufficient amount of the crosslinking agent. More preferably, the amount of the hydrophilic resin is from 20 to 97% by weight, and still more preferably from 30 to 96% by weight.
% By weight.

In the present invention, it is also preferable to use inorganic ultrafine particles having a self-forming property. Examples of the inorganic ultrafine particles in the present invention include silica (colloidal silica), water glass, alumina, and alumina hydrate (alumina sol,
Colloidal alumina, polyaluminum hydroxide, cationic aluminum oxide or hydrate thereof, pseudoboehmite, etc.), surface-treated cationic colloidal silica, zircon, zirconium hydroxide, zircon fluoride, aluminum silicate, magnesium silicate, calcium carbonate, Examples include magnesium carbonate, barium carbonate, barium sulfate, titanium dioxide, zirconium oxide, iron oxide, zinc oxide, tin oxide, magnesium oxide, antimony oxide, niobium oxide, and cerium oxide. These inorganic ultrafine particles are usually
It is used by being dispersed in a colloidal state while maintaining the primary particle diameter in a solvent. Specifically, as colloidal silica, Cataloid S series (manufactured by Catalytic Chemical Co., Ltd.), Fine Cataroid F-120, USB-120, etc. (manufactured by Catalytic Chemical Co., Ltd.), Ludox series (manufactured by DuPont), Snowtex series (Nissan) Chemical Industry Co., Ltd.), specific examples of alumina sol include Cataloid A series (Catalyst Chemical Co., Ltd.), alumina sol (Nissan Chemical Co., Ltd.), nanowhisker series (Daiichi Kagaku Kagaku Co., Ltd.), etc. Can be.

The inorganic ultrafine particles may be used alone or in combination of two or more. It is particularly preferable to use a combination of fine particles having the same kind of skeleton. For example, it is also preferable to use ultrafine colloidal silica having an average particle size of 3 to 25 nm and ultrafine colloidal silica having an average particle size of 50 to 100 nm. In such use, it is preferable to use particles having a smaller particle size as a main component, and the preferable addition amount is 50 to 100%.
More preferably 60 to 100%, even more preferably 70 to 100%
100% use. Furthermore, you may use together with a hydrophilic resin.

One of the preferred embodiments of the present invention is that the hydrophilic resin having active hydrogen in the hydrophilic binder is at least one selected from gelatin, polyvinyl alcohol, carboxymethyl cellulose, and maleic anhydride copolymer.
In this embodiment, a seed is used as a main component. The main component in the present invention means that the content is 50% or more. In a preferred embodiment, the content is 70% or more.

As the hydrophilic resin, one kind or two or more kinds of the same kind of hydrophilic resin may be used.
It may be used in combination of more than one kind.

Another preferred embodiment is an embodiment using hydrophilic inorganic ultrafine particles as a hydrophilic binder.
When inorganic ultrafine particles are used as the hydrophilic binder, it is desirable to use 5% to 20% of a hydrophilic resin in combination to prevent cracking of the coating film. If the content of the hydrophilic resin is 5% or less, there is no effect of preventing cracking, and if it exceeds 20%, the hydrophilicity may be impaired.

Next, the crosslinking agent used in the present invention will be described.

As the cross-linking agent, conventionally known cross-linking agents can be widely used as long as they can cross-link the above-mentioned hydrophilic resin. As these crosslinking agents, for example, amino resins, aziridine compounds, amino compounds, aldehydes, isocyanate compounds, carboxylic acids or acid anhydrides,
Halide, phenol-formaldehyde resin, 2
Compounds having one or more epoxy groups are included.

Particularly preferred are amino resins, amino compounds, aziridine compounds and aldehydes.

The crosslinking agent may be a low molecular weight compound or may be an oligomer or a polymer.

As the amino resin, for example, melamine,
Benzoguanamine, resins obtained by reacting urea or the like with aldehydes or ketones, specifically, for example, melamine-formaldehyde resins, urea-formaldehyde resins,
Methylolated melamine and the like. These amino resins are effective for the hydrophilic resin of the present invention having a hydroxyl group, a carboxyl group, a mercapto group, or the like.

Examples of the halide include, for example, US Pat. Nos. 3,325,287 and 3,288,775;
No. 3,549,377, Belgian Patent No. 6,62
And dichlorotriazine compounds described in JP-A-2,226. These halides are effective for hydrophilic resins having a hydroxyl group, an amino group and the like.

Examples of the amine compound and the aziridine compound include the aziridine compound described in US Pat. No. 3,392,024 and US Pat. No. 3,549,37.
No. 8, etc., and the following compounds.

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These amine compounds and aziridine compounds are effective for the hydrophilic resin of the present invention having a hydroxyl group, a carboxyl group or the like.

The isocyanate compound also includes an isocyanate having a protecting group (blocked isocyanate). Examples of these isocyanate compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalenediisocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, Examples include isophorone diisocyanate, xylene diisocyanate, lysine diisocyanate, triphenylmethane diisocyanate, and bicycloheptane diisocyanate. These isocyanate compounds are effective for a hydrophilic resin having a hydroxyl group, a carboxyl group, a mercapto group, an amino group and the like.

Examples of aldehydes include formaldehyde, glyoxal, and US Pat. No. 3,291,6.
No. 24, No. 3,232,764, French Patent No. 1,543,694, British Patent No. 1,270,578
And the dialdehydes described in (1). These aldehydes are effective for the hydrophilic resin having a hydroxyl group of the present invention.

Among these, amino resins, aziridine compounds, aldehydes and isocyanate compounds are preferred.

When gelatin is used as the hydrophilic resin,
Examples of the crosslinking agent include chromium salts (chromium meiwa, chromium acetate, etc.), aldehydes (formaldehyde, glyoxal, glutaraldehyde, etc.), N-methylol compounds (dimethylolurea, methyloldimethylhydantoin, etc.), dioxane derivatives (2,3) -Dihydroxydioxane, etc.), active vinyl compounds (1,3,5-triacryloyl-hexahydro-s-triazine, bis- (vinylsulfonyl) methyl ether, N, N'-methylenebis- [β- (vinylsulfonyl) propionamide) ]
Active halogen compounds (such as 2,4-dichloro-6-hydroxy-s-triazine), mucohalic acids (such as mucochloric acid and phenoxymucochloric acid), isoxazoles, dialdehyde starch, and 2-chloro-6. -Hydroxytriazinylated gelatin, isocyanates, carboxyl group-active cross-linking agents and the like can be used alone or in combination.

In the present invention, these crosslinking agents are preferably used in the lithographic printing plate material in an amount of 2 to 50% by weight. If the amount of the crosslinking agent is less than 2% by weight, the strength of the film becomes insufficient, and the reaction rate tends to decrease due to insufficient crosslinking point. On the other hand, if it is more than 50% by weight, the reaction of the crosslinking agent cannot be completed, and the resulting lithographic printing plate material has a large variation in performance over time, which is not preferable.

As the cross-linking agent, one or more of the same type of cross-linking agents may be used, or two or more of different types of cross-linking agents may be used in combination.

It is preferable to add a reaction accelerator for accelerating the crosslinking reaction between the hydrophilic resin and the crosslinking agent to the lithographic printing plate material. The reaction accelerator promotes a crosslinking reaction,
Thus, the overall plate manufacturing time can be reduced while maintaining the high level of cross-linking required to obtain high print resistance.

Known reaction accelerators can be used as the reaction accelerator. Examples of these reaction accelerators include, for example,
Ammonium chloride, ammonium acetate, ammonium sulfate, ammonium nitrate, ammonium phosphate, ammonium phosphate dibasic, ammonium thiocyanate, ammonium sulfamate and other ammonium salt compounds, dimethylaniline hydrochloride, pyridine hydrochloride, picoline monochloroacetic acid, catalyst AC (Manufactured by Monsanto), Catanit A (manufactured by Nitto Kagaku), Sumilizer ACX-P
(Manufactured by Sumitomo Chemical Co., Ltd.) and inorganic salt compounds such as stannic chloride, ferric chloride, magnesium chloride, zinc chloride and zinc sulfate.

It is also advantageous to use a precursor of the reaction accelerator. The precursor of the reaction accelerator is converted into a reaction accelerator when heated, and the reaction accelerator is formed as shown in the image.

Suitable precursors for the reaction accelerator are, for example, those which release an acid when heated.

These precursors include, for example, the sulfonium compounds disclosed in British Patent No. 612,065, European Patent No. 615233, and US Pat. No. 5,326,677, particularly benzylsulfonium compounds, European Patent No. 462,763, WO81 / 1755 No., inorganic nitrate U.S. disclosed in Patent No. 4,370,401 _{(e.g., Mg (NO 3) 2 ·} 6H 2 O, ammonium nitrate), organic nitrates (e.g., nitric acid Guanidinium, pyridinium nitrate) and the like, US Pat. No. 5,312,721
Compounds that release sulfonic acids, such as 3-sulfolenes, such as 2,5-dihydrothio-thiophene-1,1-dioxides, British Patent 1,
No. 4,669,747, co-crystalline adducts of amines and volatile organic acids, US Pat. No. 3,16.
Aralkyl cyanoforms disclosed in US Pat. No. 6,583, EP 159,725 and West German Patent 35.
Thermoacid disclosed in U.S. Pat. No. 1,576, squaric acid generating compound disclosed in U.S. Pat. No. 5,278,031, U.S. Pat. No. 5,225,314, U.S. Pat. No. 5,227,277. No. and Research Disclosure No. of November 1973. No. 11511.

Various fine particles can be added as a filler to the recording layer and / or the hydrophilic layer. As a preferable filler, organic or inorganic fine particles can be used.

As the organic fine particles, polymethyl methacrylate (PMMA), polystyrene, polyethylene,
Examples include fine particles of polypropylene and other radical polymerization polymers, and fine particles of condensation polymers such as polyester and polycarbonate. As a method for producing the organic fine particles, any method can be adopted.For example, a method in which polymerization is performed in a dispersion medium such as emulsion polymerization or suspension polymerization to obtain fine particles; For example, after dissolving under heating, a method of adding a poor solvent or cooling to precipitate a polymer to obtain fine particles (fine particles are easily obtained by applying a shearing force at the time of precipitation), and a method of using a sand mill or a ball mill It can be obtained by a method of obtaining fine particles by pulverizing and dispersing in a solvent by such a dispersing means, or a method of obtaining fine particles by pulverizing a polymer in a dry state and passing it through a classification step.

Examples of the inorganic fine particles include fine particles of zinc oxide, titanium oxide, barium sulfate, calcium carbonate, silica (silicon oxide) and the like. As a method for producing the inorganic fine particles, a method of obtaining fine particles by pulverizing and dispersing in a solvent by a dispersing means such as a sand mill or a ball mill can be used. When fine particles are obtained by pulverizing and dispersing in a solvent by a dispersing means such as a sand mill or a ball mill, it is preferable to use a suitable dispersant regardless of organic fine particles or inorganic fine particles.

Conventionally known inorganic fine particles can be used as long as the object of the present invention is not impaired. Examples of these inorganic fine particles include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, and silicate. Calcium, synthetic amorphous silica, aluminum hydroxide, lithopone, zeolite,
Examples include hydrohaloysite, magnesium hydroxide, and synthetic mica. Among these inorganic fine particles, porous inorganic fine particles are preferable, and as these porous inorganic fine particles, porous synthetic amorphous silica, porous calcium carbonate,
Porous alumina and the like can be mentioned, and porous synthetic amorphous silica having a large pore volume is particularly preferable.

Next, the substance used in the recording layer whose hydrophilicity changes by heat will be described in detail. The recording layer preferably contains self-water-dispersible resin particles that are fused by heat to lower the hydrophilicity. Examples of the self-water dispersible resin include a salt of a synthetic resin having an acid value and a basic substance, and a resin having a hydrophilic group such as a hydroxyl group as a substituent. In order to prevent dissolution and swelling of the particles and to impart large hydrophilicity to the particles, it is preferable that at least a part of the synthetic resin having an acid value of 50 to 280 is neutralized with a base. In particular, in order to prevent fusion of the resin particles, the glass transition temperature of the resin is preferably 50 ° C. or higher, more preferably 70 ° C. or higher.

Specifically, for example, substituted styrenes such as styrene or α-methylstyrene, acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and methacrylic acid At least one monomer unit selected from methacrylic acid esters such as methyl ester, methacrylic acid ethyl ester, methacrylic acid butyl ester, and methacrylic acid 2-ethylhexyl ester; and at least one monomer selected from acrylic acid and methacrylic acid Copolymers containing units are preferred. Although there is no particular limitation on the molecular weight range of the resin, those having a molecular weight of 1,000 to 100,000 are more preferable.

As means for further improving the adhesion of the resin to the substrate surface, the abrasion resistance, oil resistance, and alkali resistance of the image area, and the prevention of fusion of particles in the non-image area, self-water dispersibility It is preferable that the thermoplastic resin is an ionomer resin having a structure in which at least a part of the total amount of the functional groups that give an acid value in the synthetic resin is intermolecularly crosslinked via a polyvalent metal ion and integrated.

The polyvalent metal ion used in the ionomer resin may have any valence of 2 or more, but is preferably 2 or 3, and is particularly preferably calcium ion, barium ion, magnesium ion, zinc ion, or aluminum. Resin particles obtained from at least one selected from ions are colorless, less toxic, tough and show good thermoplasticity. Crosslinking of the resin with these polyvalent metal ions is preferably carried out with one of the anionic functional groups.
%, The gelation of the synthetic resin is small, and a stable ionomer resin aqueous dispersion is obtained, and the decrease in the heat fluidity of the resin particles is small.

Further, the recording layer may contain a component having lipophilicity in advance, in addition to the above-mentioned substance whose hydrophilicity is reduced. Specifically, for example, phenyl isocyanate, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 1,5-naphthalenediisocyanate, triazine diisocyanate,
1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, bicycloheptane triisocyanate, triden diisocyanate, polymethylene polyphenyl isocyanate, isocyanate such as polymeric polyisocyanate, and trimethylolpropane. Isocyanate compounds such as polyisocyanates such as 1,3-hexane adducts with the above isocyanates such as 1,6-hexane diisocyanate or 2,4-tolylene diisocyanate, oligomers or polymers of 2-isocyanatoethyl (meth) acrylate, and the like: N, N'-methylenebisacrylamide (meth) acryloylmorpholine, vinylpyridine, N-methyl (methyl ) Acrylamide, N, N'-dimethyl (meth) acrylamide, N, N'-dimethylaminopropyl (meth) acrylamide, N, N'-dimethylaminoethyl (meth) acrylate, N, N'-diethylaminoethyl (meth) Acrylate, N, N'-
Dimethylaminoneopentyl (meth) acrylate, N
-Vinyl-2-pyrrolidone, diacetone acrylamide, N-methylol (meth) acrylamide, p-styrenesulfonic acid or a salt thereof, methoxytriethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) Acrylate (PEG number average molecular weight 400), methoxy polyethylene glycol (meth) acrylate (PEG number average molecular weight 100)
0), butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, dimethylol Tricyclodecane di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate (PEG number average molecular weight 40
0), polyethylene glycol di (meth) acrylate (number average molecular weight of PEG 600), polyethylene glycol di (meth) acrylate (number average molecular weight of PEG 1)
000), polypropylene glycol di (meth) acrylate (PPG number average molecular weight 400), 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy diethoxy) phenyl] Propane, 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane or an acrylate thereof, β- (meth) acryloyloxyethyl hydrogen phthalate, β- (meth) acryloyloxyethyl hydrogen succinate, polyethylene or Polypropylene glycol mono (meth) acrylate, 3-chloro-2-hydroxypropyl (meth)
Acrylate, 1,3-butylene glycol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, Isobornyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate,
Stearyl (meth) acrylate, isodecyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Tetrafurfuryl (meth) acrylate, benzyl (meth) acrylate, mono (2-acryloyloxyethyl) acid phosphate, or its methacrylic body, glycerin mono- or di (meth) acrylate, tris (2
-Acryloxyethyl) isocyanurate or a methacrylic body thereof, polyfunctional (meth) acrylate monomers such as 2-isocyanatoethyl (meth) acrylate, or a combination thereof with a monofunctional (meth) acrylate;
Further, a combination with a (meth) acrylate monomer having a hydrophilic group: N-phenylmaleimide, N- (meth) acryloxysuccinimide, N-vinylcarbazole, divinylethylene urea, divinylpropylene urea, triallyl isocyanurate Such as a polyfunctional allyl compound or a combination thereof with a monofunctional allyl compound,
Furthermore, a hydroxyl group, a carboxyl group, an amino group, a vinyl group,
Liquid rubbers such as 1,2-polybutadiene and isoprene containing reactive groups such as thiol groups and epoxy groups at both ends of polymer molecules, various telechelic polymers such as urethane (meth) acrylate, and carbon-carbon unsaturated groups , Hydroxyl group, carboxyl group, amino group, epoxy group-containing reactive wax, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether,
Polyfunctional epoxy compounds such as polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl ether can be used. Further, known (meth) acrylic copolymers, urethane acrylates, and diazo resins before crosslinking, which are used as image components of existing PS plates, can also be used.

As the lipophilic substance, wax dispersion,
Thermoplastic lipophilic resin particles, a low molecular hydrophobic substance, a water repellent and the like can be added. Specific wax dispersions include vegetable waxes such as carnauba wax, wood wax, ouriculi wax, and Espal wax; animal waxes such as beeswax, insect wax, shellac wax, and spermaceti; paraffin wax, microcrystalline wax, polyethylene wax, Examples include waxes such as petroleum wax such as amide wax, ester wax and sun wax; and mineral wax such as montan wax, ozokerite and ceresin.

The thermoplastic lipophilic resin particles include ethylene copolymer, styrene copolymer, polyamide resin, polyester resin, polyurethane resin, polyolefin resin, acrylic resin, vinyl chloride resin,
Resins such as polyvinylidene chloride resin, polyvinyl carbazole resin, cellulose resin, rosin resin, polyvinyl alcohol resin, polyvinyl acetal resin, ionomer resin, petroleum resin; natural rubber, styrene butadiene rubber, isoprene rubber, Elastomers such as chloroprene rubber and diene copolymer; ester gum, rosin maleic resin, rosin phenol resin,
Rosin derivatives such as hydrogenated rosin; and phenolic resins,
Examples include particles of terpene resin, cyclopentadiene resin, aromatic hydrocarbon resin, and the like.

Examples of the low molecular weight hydrophobic substance include alcohols such as terpineol, menthol, 1,4-cyclohexanediol, and phenol; amides such as acetamide and benzamide; esters such as coumarin and benzyl cinnamate; diphenyl ether and crown ether Ketones such as camphor and p-methylacetophenone; aldehydes such as vanillin and dimethoxybenzaldehyde; hydrocarbons such as norbornene and stilbene; higher fatty acids such as palmitic acid, stearic acid, margaric acid and behenic acid; Higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol, and eicosanol; cetyl palmitate, myricyl palmitate, and cetyl stearate Fatty acid esters such as amide, myricyl stearate; amides such as acetamide, propionamide, palmitic amide, stearic amide, amide wax; and higher amines such as stearylamine, behenylamine, palmitylamine; phthalic acid esters , Trimellitic acid esters, adipic acid esters, other saturated or unsaturated carboxylic acid esters, citric acid esters, epoxidized soybean oil, epoxidized linseed oil, epoxy stearate, orthophosphoric acid esters, nitrite Phosphoric esters, glycol esters and the like can be mentioned.

As the water repellent, conventionally known silicone compounds, fluorine compounds and the like can be suitably used. Examples of such a material include silicone surfactants such as Silwet L720, FZ2122. FZ
2120, FZ2166, FZ2171 (manufactured by Nippon Unicar Co., Ltd.) and the like, and also a silane coupling agent: for example, a carboxyl group, a mercapto group, an isocyanate group, a glycidyl group-containing coupling agent containing an unsaturated group, and an amino group-containing coupling agent And N-3.
-(Acryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, (3-acryloxypropyl) methyldimethoxysilane, (3-acryloxypropyl) trimethoxysilane , 3- (N-allylamino) propyltrimethoxysilane, allyldimethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, 3-butenyltriethoxysilane, 2-
(Chloromethyl) allyltrimethoxysilane, methacrylamidopropyltriethoxysilane, N- (3-methacryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, (methacryloxymethyl)
Dimethylethoxysilane, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxypropyldimethylethoxysilane,
Methacryloxypropyldimethylmethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, methacryloxypropylmethyltriethoxysilane, methacryloxypropylmethyltrimethoxysilane, methacryloxypropyltris (methoxyethoxy) silane, methoxydimethyl Vinylsilane, 1-methoxy-3- (trimethylsiloxy) butadiene, styrylethyltrimethoxysilane, 3- (N-styrylmethyl-2-aminoethylamino) -propyltrimethoxysilane hydrochloride, vinyldimethylethoxysilane, vinyldiphenylethoxy Silane, vinylmethyldiethoxysilane, vinylmethyldimethoxysilane, o- (vinyloxyethyl) -N- (triethoxysilyl Pills) urethane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl tri -t
-Butoxysilane, vinyltriisopropoxysilane,
Examples include vinyltriphenoxysilane, vinyltris (2-methoxyethoxy) silane, and diallylaminopropylmethoxysilane. Preferably, a coupling agent containing a methacryloyl group or an acryloyl group having a high reactivity of an unsaturated group is preferable. If the saturated group is bifunctional, a vinyl group or an allyl group may be used.

1) The amino group-containing coupling agent is
It preferably contains various types of amino groups such as primary, secondary, tertiary, and quaternary, and particularly preferably contains secondary amino groups. Specific compounds are 4
-Aminobutyltriethoxysilane, 4-aminobutyltrimethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N
-(2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (6-aminohexyl) aminopropyltrimethoxysilane, 3- (M-aminophenoxy)
Propyltrimethoxysilane, m-aminophenyltrimethoxysilane, p-aminophenyltrimethoxysilane, 3-aminopropyldimethylethoxysilane, 3-
Aminopropylmethyldiethoxysilane, aminopropylsilanetriol-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-
Aminopropyltris (methoxyethoxyethoxy) silane, 3-aminopropyltris (trimethylsiloxy) silane, N-methylaminopropyltrimethoxysilane, (3-trimethoxysilylpropyl) diethylenetriamine, N- (trimethoxypropyl) isothiouronium Chloride and γ-ureidopropyltriethoxysilane.

2) Glycidyl group-containing coupling agents include 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, (3-glycidoxypropyl) dimethylethoxysilane, and (3-glycidoxypropyl) methyl Diethoxysilane, (3-glycidoxypropyl)
Methyldimethoxysilane, (3-glycidoxypropyl) trimethoxysilane and the like can be mentioned.

Examples of the fluorine compound include fluorine surfactants: acrylates containing a fluoroaliphatic group,
Copolymers of methacrylate and (polyoxyalkylene) acrylate or (polyoxyalkylene) methacrylate, JP-A-62-170950, JP-A-62-2
No. 26143 and U.S. Pat. No. 3,787,351. For example, Mega Fuck F-
171, 173, 177, 179, 142D, Defensor MCF300, 312, 313 (manufactured by Dainippon Ink and Chemicals, Inc.), Modiper F-100, 102, 1
10 (manufactured by NOF CORPORATION) and JP-A-64-1814.
The fluorine-containing acrylic resin described in No. 2, etc. Tokuhei 6-10
No. 5,351, JP-B-8-3630, JP-A-3-172
No. 849. Fluorinated surfactant. JP-A-1-260
055, JP-A-1-271478, JP-A-4-63
No. 802 can be preferably used. Of these materials, particularly preferred are those at room temperature /
A hydrophilic fluorine-containing oligomer capable of forming a dispersion state in an aqueous liquid is preferable. As a specific product, Asahigard AG422, 428, 490, 530, 55
0, 710, 780, 880, 970, LS317 (manufactured by Asahi Glass Co., Ltd.), TK Guard 505 (manufactured by Takamatsu Yushi Co., Ltd.), Dickguard F-52S, F-70, F1
8, F-90, F-90N, and FS-90H (manufactured by Dainippon Ink and Chemicals, Inc.). Among them, those having a side chain of a perfluoroalkyl group having 5 to 15 carbon atoms are preferable, and those having 6 to 12 carbon atoms are particularly preferable. The lipophilic component may be solid or liquid at room temperature.

Next, the light-heat conversion agent will be described.
The heat conversion agent may be present anywhere if the heat generated by the light-heat conversion can be transmitted to the recording layer, may be present in the hydrophilic layer, or may be present in a layer different from the hydrophilic layer. Good, but preferably a hydrophilic layer. Further, it may be present on a support. The light-heat conversion agent is preferably a material that absorbs light and efficiently converts it to heat, and varies depending on the light source used.For example, when a semiconductor laser that emits near-infrared light is used as the light source, the light-to-infrared Near infrared light absorbers having an absorption band are preferred. In wavelength, 700 nm or more and 120
Those having a maximum absorption at 0 nm or less, for example, carbon black, cyanine dyes, polymethine dyes,
Organic compounds such as azurenium-based dyes, squarium-based dyes, thiopyrylium-based dyes, naphthoquinone-based dyes, and anthraquinone-based dyes, and phthalocyanine-based, azo-based, and thioamide-based organic metal complexes are preferably used. Specifically, JP-A-63-139191 and JP-A-64-3354
No. 7, JP-A-1-160683 and 1-280750
Nos. 1-293342, 2-2074, 3-
No. 26593, No. 3-30991, No. 3-34891
No. 3-36093, No. 3-36094, No. 3-
No. 36095, No. 3-42281, No. 3-97589
And the compounds described in JP-A Nos. 3-103476 and 3-103476. These can be used alone or in combination of two or more. The transmission density at that time is 1.0 or more, preferably 2.0 or more.

The light-to-heat converting agent can be used as a vapor-deposited film. Examples of the light-to-heat converting agent vapor-deposited film include a carbon black vapor-deposited film and JP-A-52-2084.
No. 2 described above include metal black deposited films of gold, silver, aluminum, chromium, nickel, antimony, tellurium, bismuth, selenium and the like, and deposited films containing colloidal silver.

When the light-to-heat conversion agent is present in a layer different from the hydrophilic layer and the recording layer, it is preferable that the light-heat conversion agent be present in a layer to which a binder has been added. As the binder, a resin having a high Tg and a high thermal conductivity is preferably used. For example, polymethyl methacrylate, polycarbonate, polystyrene, ethyl cellulose, nitrocellulose, polyvinyl alcohol (PVA), polyvinyl chloride, polyamide, polyimide, General heat-resistant resins such as polyetherimide, polysulfone, polyethersulfone, and aramid can be used.

Further, as the binder, a water-soluble polymer can also be used. The water-soluble polymer is preferable because it has good heat resistance at the time of light irradiation, and so-called scattering is small even with excessive heating. When a water-soluble polymer is used, it is desirable that the light-to-heat conversion agent be modified to be water-soluble by means such as introduction of a sulfo group or dispersed in an aqueous system.

Gelatin and PVA have little aggregation of water-soluble infrared-absorbing dyes, can stably coat a layer containing a light-to-heat conversion agent, are excellent in storage stability of a recording medium, have color turbidity due to aggregation of infrared-absorbing dyes, This is preferable because there is no decrease in sensitivity.

When the light-heat conversion agent-containing layer is provided separately from the recording layer and the hydrophilic layer, the thickness is preferably 0.1 μm to 3 μm.
More preferably, it is 0.2 μm to 1.0 μm. Also light-
The content of the heat converting agent is usually such that the absorbance at the wavelength of the light source used for image recording is 0.3 to 3.0, more preferably 0.7.
It can be determined to be 2.5.

The thickness of the recording layer is preferably from 1 μm to 30 μm. More preferably, it is 2 μm to 10 μm.

The recording layer according to the present invention, when heated, loses its hydrophilicity and changes its physical properties to hydrophobic.

In one embodiment, a substance whose hydrophilicity is reduced by heat in a heated portion or a substance which becomes water-repellent by heating is changed from hydrophilic to hydrophobic by being heated in an image-like manner. In another aspect, a lipophilic substance in a hydrophilic binder is melted by heat and changes from hydrophilic to hydrophobic by mixing and melting with a hydrophilic binder, or a hydrophilic substance formed by a hydrophilic binder. A substance that changes from hydrophilic to hydrophobic by selectively exuding a lipophilic substance to the surface is mentioned.

The hydrophilic layer according to the present invention is provided on the above-mentioned recording layer, and plays a role of enhancing the hydrophilicity, that is, the stain resistance during printing. According to the first embodiment, the hydrophilic layer is ablated by laser exposure and is perforated and removed in an image-like manner. At that time, the surface of the recording layer changed from hydrophilic to hydrophobic is exposed, and the difference between hydrophilicity and lipophilicity is obtained. Can be increased. According to the second embodiment, the difference between hydrophilicity and lipophilicity can be increased by leaching the lipophilic component of the recording layer through the hydrophilic layer and onto the surface of the hydrophilic layer by laser exposure. At this time, the thickness of the hydrophilic layer is reduced by the heat of the laser exposure, and the penetration of the lipophilic substance can be promoted.

The hydrophilic layer is preferably a thin film to facilitate ablation or to easily penetrate a lipophilic substance, but if it is too thin, the effect of the hydrophilic layer cannot be obtained. The preferred thickness is 0.1 μm to 2.0 μm, and more preferably 0.2 μm to 1.0 μm. 2.0μ thickness
If it exceeds m, removal by hydrophilic laser ablation or penetration of lipophilic substances may be insufficient. On the other hand, when the thickness is less than 0.1 μm, the strength of the hydrophilic layer is insufficient, and stains may occur during printing.

The hydrophilic layer has a hydrogen bond component (H) having a surface energy γ of 20 or more, and the surface energy γ
Is preferably 40 or less.

In the lithographic printing plate material of the present invention, the surface on the recording layer side or on the opposite side is preferably roughened. The method of surface roughening is arbitrary, but when the surface roughening is performed by coating, the coating solution may be any as long as it does not substantially adversely affect the lithographic printing plate material physically or chemically. For example, the roughened layer is a layer that is mechanically matted or a resin layer that contains a matting agent. As a method of mechanically matting, 1) a method of applying a roughened layer so as to obtain a coating layer having an uneven pattern, and 2) a method of forming a roughened layer mechanically to form a roughened layer. is there.

As a specific example of 1), a method of applying a roughened layer with a gravure roll having an uneven pattern, a method of spraying resin particles and heat-sealing to obtain an uneven pattern, and the like can be mentioned.

As a specific example of 2), there is a method in which a roughened layer is provided, and then a mat is formed by pressing with a pressure roller having an uneven surface having a hardness higher than the hardness of the roughened layer. The support itself may be formed into a mat by applying pressure.

When a metal support is not used as the support, the chargeability can be suppressed and the handleability can be improved by adding a conductive agent to the roughened layer on the back surface.

The thickness of the roughened layer is preferably 2 to 30 μm. When the roughened layer is thinner than 2 μm, or 3
If it exceeds 0 μm, it is difficult to obtain a desired roughness.

In the case of the resin layer containing a matting agent, the particle size of the particles of the matting agent used is suitably in the range of 1 to 30 μm, and particularly preferably in the range of 2 to 10 μm.

As the filler used as the matting agent, the same solid particles as those used for the recording layer can be used.

The lithographic printing plate material of the present invention can be obtained by coating and drying a recording layer and a hydrophilic layer in this order on the following support.

As the support, a conventionally known support can be used without any particular limitation. The material, the layer structure, the size, and the like are appropriately selected and used according to the purpose of use and the like. For example, paper, coated paper, synthetic paper (polypropylene, polystyrene, or a composite material obtained by laminating them with paper)
, Vinyl chloride resin sheet, ABS resin sheet, polyethylene terephthalate (PET) film, polybutylene terephthalate film, polyethylene naphthalate (PEN) film, polyarylate film, polycarbonate film, polyetherketone film, polysulfone film , Polyethersulfone films, polyetherimide films, polyimide films, polyethylene films, polypropylene films, etc., or various plastic films or sheets obtained by laminating two or more layers thereof, films or sheets formed of various metals, various types Films or sheets made of ceramics, and metal plates such as aluminum, stainless steel, chromium, nickel, etc., and thin metal films on resin-coated paper Include those prepared by laminating or vapor deposition.

In the case of a support having a hydrophobic surface, a hydrophilic treatment can be applied to the surface. As the hydrophilization treatment method, sulfuric acid treatment, oxygen plasma etching treatment, corona discharge treatment, application of a water-soluble resin, and the like are preferably used.

The lithographic printing plate material of the present invention is prepared by applying a coating solution for a recording layer containing a hydrophilic resin and, if necessary, a crosslinking agent, a light-to-heat conversion agent, a filler and other additives to the support. After forming the recording layer, a hydrophilic layer coating solution containing a hydrophilic resin, a light-to-heat converter, and other additives, if necessary, is applied and dried to form a hydrophilic layer. be able to. When the light-to-heat conversion agent-containing layer is provided as a separate layer, a coating solution containing the light-to-heat conversion agent is prepared, coated and dried in the same manner as in the hydrophilic layer, and dried.
What is necessary is just to form a heat conversion agent containing layer.

The drying temperature is 30 to 100 ° C., preferably 30 to 80 ° C., and more preferably 30 to 70 ° C. The drying time is preferably from 30 seconds to 10 minutes, more preferably from 1 minute to 5 minutes.

In a preferred embodiment of the lithographic printing plate material of the present invention, two kinds of crosslinking agents having different reactivities are used.
For example, by using a urea resin and a melamine resin in combination as a cross-linking agent, an amount of a urea resin component having excellent reactivity at a low temperature is added in an amount sufficient to improve film strength, and further, a heat treatment is performed. It is a preferred embodiment to promote the reaction of the melamine component by proceeding and to form an image area by crushing the polar group of the hydrophilic resin. In a preferred embodiment, two or more crosslinking agents are contained, and an accelerator which selectively acts on only one of the crosslinking agents is added. By doing so, it is possible to limit the reaction at a low temperature and allow the remaining crosslinking agent to function when a high temperature is generated.

In the lithographic printing plate material of the present invention, various types of back layers may be provided on the side opposite to the heat-sensitive layer side in order to prevent curling and to prevent sticking when superimposed immediately after printing. it can.

The center line average roughness Ra of the recording layer side surface of the lithographic printing plate material thus obtained is preferably 0.3 μm or more, more preferably 0.5 μm or more. If it is less than 0.3 μm, problems may occur in water retention, transportability, and blocking properties. This Ra can be measured using, for example, RST / PLUS (manufactured by WYCO).

Examples of the method of forming an image on the lithographic printing plate material of the present invention include a method of applying thermal energy directly to an image by a thermal head or the like, a method of irradiating high-output light energy image-wise, Is converted into heat energy and applied.

The method of directly applying thermal energy to an image using a thermal head or the like is preferable when it is inexpensive and uses low-resolution or line image output as its main purpose. The method of irradiating the laser beam with heat and converting it into heat energy is preferable because high-definition writing can be easily performed, and thus, when high-resolution or half-tone image output is mainly used as in commercial printing.

Examples of light sources for image exposure include lasers, light-emitting diodes, xenon flash lamps, halogen lamps, carbon arc lamps, metal halide lamps, tungsten lamps, high-pressure mercury lamps, and electrodeless light sources.

In order to irradiate high-output light energy imagewise, a mask material having a desired exposure image pattern formed of a light-shielding material is superimposed on a lithographic printing plate material, and a xenon lamp, a halogen lamp, and a carbon arc lamp are used. , Metal halide lamp, tungsten lamp, high pressure mercury lamp,
The batch exposure may be performed using an electrodeless light source or the like.

When exposing using an array-type light source such as a light-emitting diode array or controlling a light source such as a halogen lamp, a metal halide lamp, or a tungsten lamp with an optical shutter material such as a liquid crystal or PLZT,
Digital exposure according to an image signal can be performed, which is preferable. In this case, writing can be performed directly without using a mask material.

When a laser is used for exposure, light can be focused into a beam and scanning exposure can be performed in accordance with image data. Therefore, direct writing can be performed without using a mask material. When using a laser as a light source,
It is easy to narrow the exposure area to a very small size, and it is possible to form a high-resolution image. As a laser light source, any of an argon laser, a He—Ne gas laser, a YAG laser, and a semiconductor laser can be suitably used.

Among these, the use of semiconductor lasers and YAG lasers is more preferable because high output suitable for the lithographic printing plate material of the present invention can be incorporated into a small device at a relatively low cost.

As a laser scanning exposure method, there is an exposure method using a cylinder outer surface scan, a cylinder inner surface scan, a plane scan, or the like. In scanning the outer surface of the cylinder, laser irradiation is performed while rotating a drum around which a recording material is wound around the outer surface. In this case, the rotation of the drum is the main scanning, and the movement of the laser beam is the sub-scanning. In the cylinder inner surface scanning, a recording material is fixed on the inner surface of a drum, and a laser beam is irradiated from the inside. In this case, main scanning is performed in the circumferential direction by rotating part or all of the optical system, and sub-scanning is performed in the axial direction by linearly moving part or all of the optical system parallel to the axis of the drum. . In the planar scanning, the main scanning of the laser beam is performed by combining a polygon mirror or a galvanometer mirror with an fθ lens or the like, and the sub-scanning is performed by moving the recording medium. The cylinder outer surface scanning and the cylinder inner surface scanning easily increase the precision of the optical system and are suitable for high-density recording.

The image formation (plate making) on the lithographic printing plate material of the present invention can be performed only by the above-mentioned image exposure, and the non-image portion removal processing is conventionally performed by developing using a liquid. It is not required. For this reason, an image is formed on the lithographic printing plate material of the present invention by a dedicated exposure apparatus, and the obtained lithographic printing plate can be used by being loaded into a printing machine, or an image can be formed on a plate cylinder. It can also be used as a system for forming and printing as it is.

[0128]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. In addition, the following “parts” indicates “parts by weight”.

Example 1 A lithographic printing plate material was prepared by providing the following layers on a PET film that had been subjected to a gelatin subbing treatment.

(Recording layer coating liquid) Polyvinyl alcohol (Z-100: manufactured by Nippon Synthetic Chemical Co., Ltd.) 20.0 parts Ionomer resin aqueous dispersion (S-650: manufactured by Mitsui Petrochemical, solid content 27%) 30.0 parts Silica particles (inorganic treated product: Sylysia 435: manufactured by Fuji Silysia Chemical Ltd.) 30.0 parts Melamine resin (Sumirez Resin 613: manufactured by Sumitomo Chemical Co., Ltd.) 5.0 parts as solids Organic amine salt (Sumirez) Accelerator ACX-P: 1.0 part as a solid content of carbon black (SD9020: manufactured by Dainippon Ink Co., Ltd.) 10.0 parts as a solid content 10.0 parts as a solid content of the recording layer so that the dried layer coating liquid has a dry film thickness of 5 μm. Applied.

(Hydrophilic layer coating liquid) Self-imitation ultrafine particles (Snowtex S: Nissan Chemical Industries, Ltd.) 70.0 parts Gelatin 5.0 parts Silica particles (Syloid 7000: Grace Japan) 30.0 Part Infrared absorbing dye (CY-17: manufactured by Nippon Kayaku) 10.0 parts The hydrophilic layer coating liquid was applied so as to have a dry film thickness of 0.5 μm.

The hydrogen bond component (H) of the surface energy γ of this hydrophilic layer is 43.3, and the surface energy γ
Had a cohesive force component (d) of 29.5. Surface roughness R
a was 1.1 μm.

Example 2 A lithographic printing plate material was prepared by providing the following layers on a PET film that had been subjected to a gelatin subbing treatment.

(Recording Layer Coating Solution) Self-Improving Ultrafine Particles (Snowtex S) 20.0 parts Gelatin 5.0 parts Wax emulsion (A101: manufactured by Gifu Shellac Co., Ltd.) 34.0 parts Silica particles (the above Inorganic treated product: Sylysia 435) 30.0 parts Carbon black (SD9020: manufactured by Dainippon Ink Co., Ltd.) 10.0 parts as solids A recording layer coating liquid was applied to a dry film thickness of 5 μm.

(Hydrophilic Layer Coating Solution) Self-Imitation Fine Particles (Snowtex S) 70.0 Parts Silica Particles (Inorganic Treated Silica: Sylysia 435) 10.0 Parts Polyvinyl Alcohol (Z-100) 10 0.0 part Infrared absorbing dye (CY-17: manufactured by Nippon Kayaku) 10.0 parts A hydrophilic layer coating solution was applied so as to have a dry film thickness of 0.8 μm.

The hydrogen bond component (H) of the surface energy γ of this hydrophilic layer was 40.9, and the cohesive force component (d) of the surface energy γ was 32.7. Surface roughness Ra
Was 0.8 μm.

Example 3 A lithographic printing plate material was prepared by providing the following layers on a PET film that had been subjected to a gelatin subbing treatment.

(Recording Layer Coating Solution) Self-Improving Ultrafine Particles (Snowtex S) 20.0 parts Polyvinyl alcohol (Z-100) 5.0 parts Wax emulsion (A101) 34.0 parts Silica particles (The above-mentioned inorganic treated product: Sylysia 435) 30.0 parts Carbon black (the above-mentioned SD9020) 10.0 parts as a solid content A recording layer coating liquid was applied to a dry film thickness of 5 μm.

(Hydrophilic Layer Coating Solution) Self-Imitation Fine Particles (Alumina Sol 520: Nissan Chemical Industries, Ltd.) 70.0 parts Silica particles (the inorganic-treated silica: Sylysia 435) 30.0 parts Polyvinyl alcohol (the Z -100) 10.0 parts Infrared absorbing dye (CY-17) 10.0 parts The hydrophilic layer coating solution was applied to a dry film thickness of 0.5 μm.

The hydrogen bond component (H) of the surface energy γ of this hydrophilic layer was 50.8, and the cohesive force component (d) of the surface energy γ was 21.1. Surface roughness Ra
Was 0.9 μm.

Example 4 A lithographic printing plate material was prepared by providing the following layers on an aluminum support coated with a urethane-based adhesive.

(Recording Layer Coating Solution) Self-Improving Ultrafine Particles (Snowtex S) 20.0 parts Polyvinyl Alcohol (Z-100) 5.0 parts Wax Emulsion (A101: Gifu Shellac Co., Ltd.) 34 0.0 parts Silica particles (the above-mentioned inorganic treated product: Sylysia 435) 30.0 parts Carbon black (the above-mentioned SD9020) 10.0 parts as a solid content A recording layer coating liquid was applied to a dry film thickness of 8 μm.

(Hydrophilic layer coating liquid) Self-imitation fine particles (Alumina sol 520) 70.0 parts Silica particles (Inorganic treated silica: Sylysia 435) 30.0 parts Polyvinyl alcohol (Z-100) 0 parts Infrared absorbing dye (CY-17) 10.0 parts The coating solution for the hydrophilic layer was applied so as to have a dry film thickness of 0.5 μm.

The hydrogen bond component (H) of the surface energy γ of this hydrophilic layer was 50.8, and the cohesive force component (d) of the surface energy γ was 21.1. Surface roughness Ra
Was 0.9 μm.

Example 5 (Comparative Example 1) A lithographic printing plate material was obtained in the same manner as in Example 4 except that the hydrophilic layer was omitted. The hydrogen bond component (H) of the surface energy γ of this hydrophilic layer is 7.1, and the surface energy γ
Had a cohesive force component (d) of 22.5. Surface roughness R
a was 0.3 μm. Apply 6 μm dry film coating solution
m.

Example 6 (Comparative Example 2) A lithographic printing plate material was prepared by providing the following recording layer coating solution on an aluminum support coated with a urethane-based adhesive.

(Coating solution for recording layer) Hydroxyethyl acrylate, acrylic acid, acrylamide copolymer copolymer (Compound 1) 12 parts Dimethylbiphenyl diisocyanate (Compound 2) microencapsulated with polyvinyl alcohol 6 parts AIBN (azoisobuty) (Ronitrile) 1 part Calcium carbonate 0.8 part Zinc stearate 0.5 part Carbon black (SD9020) 10.0 parts as solids A recording layer coating liquid was applied to a dry film thickness of 4.5 μm.

Example 7 (Comparative Example 3) A lithographic printing plate material was prepared by providing the following recording layer coating solution on an aluminum support coated with a urethane-based adhesive.

(Recording Layer Coating Solution) Styrene Acrylic Resin 20 parts Triethanolamine 3.1 parts Methyl ethyl ketone 20 parts Isopropyl alcohol 10 parts Carbon black (SD9020) 10.0 parts as a solid content Drying of the recording layer coating solution It was applied to a thickness of 5 μm.

The lithographic printing plate material thus obtained was used for 83
The recording was performed by irradiating an exposure energy of 200 mj / cm ² with a printing apparatus equipped with a semiconductor laser having an emission wavelength of 0 nm and an output of 500 mw. The laser beam diameter was 20 μm at 1 / e ² of the intensity at the peak. The resolution is 1000, 2000, 4000d in both the scanning direction and the sub-scanning direction.
pi.

The obtained lithographic printing plate was printed on wood free paper by an offset printing machine without performing liquid development, and the following evaluation was performed.

<< Evaluation >> The sensitivity, small dot reproducibility and printing durability were evaluated as follows. Tables 1 and 2 show the obtained results.

<Sensitivity> Exposure was performed under the above conditions, and the developing ink was uniformly applied to the solid portion of the exposed portion (Fuji Film Co., Ltd .: P
Exposure energy (mj /
cm ² ) was determined and evaluated using this exposure energy value.

<Resolution> Exposure was carried out under the above conditions, and the developing ink (manufactured by Fuji Film Co., Ltd .:
Exposure energy (mj) required to receive PI-2)
/ Cm ² ) and exposure with the exposure energy value.
Observation was performed with a 0-magnifying loupe, and the range (line / inch) of the resolving power that was well reproduced was visually evaluated.

<Printing durability> Exposure was performed under the above conditions, the exposure energy value required for the solid portion to uniformly receive the ink and printing was obtained, and the exposure energy value was used to perform exposure.
Create a 75-line image and use a printing machine (Heidel GTO)
Coated paper, printing ink (manufactured by Toyo Ink Manufacturing Co., Ltd .: High Plus M Red) and dampening solution (manufactured by Konica Corporation: SEU)
-32.5% aqueous solution), and printing is continued until a defective inking appears on a solid portion of an image of a printed matter or ink is deposited on a non-image portion, and the number of printed sheets at that time is counted. The printing durability was evaluated based on this number.

<Print Stain> In the above evaluation of printing durability,
At the time of printing, water was gradually squeezed out from a normal water-ink balance, and evaluation was made based on the number of sheets at which soiling began to occur.

<Preservation property> After leaving for 5 days in a constant temperature bath at a temperature of 55 ° C. and a humidity of 50%, it was taken out, returned to normal temperature, exposed under the above conditions to obtain a lithographic printing plate, and the lithographic printing plate was used. Using a printing machine (Heidel GTO), coated paper, printing ink (manufactured by Toyo Ink Mfg. Co., Ltd .: High Plus M Red) and fountain solution (Konica Corporation: SEU-3 2.5% aqueous solution) And printing was performed, and the stain on the non-image area was evaluated according to the following evaluation criteria.

(Evaluation Criteria) ・ ・ ・: No dirt Δ: Dirt is slightly visible X: Dirt is present.

The results are shown in Tables 1 and 2 below.

[0160]

[Table 1]

[0161]

[Table 2]

As is clear from Tables 1 and 2, the lithographic printing plate material of the present invention can directly make a plate from an electric signal from a computer, and can adopt a dry treatment. It can be seen that the sample has excellent ink deposition stability in the image area, no printing stains in the non-image area, high sensitivity, excellent resolution, and good storage stability and printing durability.

[0163]

According to the lithographic printing plate material of the present invention, a lithographic printing plate can be prepared by dry treatment, there is no need for waste liquid treatment, the lithographic printing plate preparation process can be shortened, and the lithographic printing plate material has excellent sensitivity and noise. It has excellent strength in both image area and non-image area, excellent printing durability, no stop stain, wide water width, and can produce a high resolution lithographic printing plate. It works.

Continuing from the front page (72) Inventor Saburo Hiraoka 1st Sakuramachi, Hino-shi, Tokyo Konica Corporation In-house

Claims (6)

[Claims] 1. A lithographic printing plate material comprising: a recording layer having hydrophilicity reduced by heat and a hydrophilic layer having a maximum absorption in an infrared light region formed on a support in this order. 2. The method according to claim 1, wherein the hydrophilic layer has a thickness of 700 nm or more and 1200 or more.
2. The lithographic printing plate material according to claim 1, wherein the material has a maximum absorption at a wavelength of not more than nm and a transmission density at the maximum absorption is 1.0 or more. 3. The lithographic printing plate material according to claim 1, wherein the dry thickness of the hydrophilic layer is 1.0 μm or less. 4. The hydrophilic layer according to claim 1, wherein the hydrogen bond component (H) of the surface energy γ is 20 or more, and the cohesive force component (d) of the surface energy γ is 40 or less. 4. The lithographic printing plate material according to 1, 2, or 3. 5. The lithographic printing plate material according to claim 1, wherein the center line average roughness Ra of the recording layer side surface is 0.5 or more. 6. The lithographic printing plate material according to claim 1, 2 or 3 is irradiated with a laser beam of 1 W / cm ² or more imagewise to remove a hydrophilic layer in a laser beam irradiated portion. And a method for making a lithographic printing plate, wherein the hydrophilicity of the recording layer in the irradiated part is reduced.