JPH10250253A - Direct drawing type waterless lithographic printing original plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a plate checking property by a method wherein a heat sensitive layer and a silicone rubber layer are successively laminated on a substrate, and the heat sensitive layer contains a light to heat converting substance and a substance which is dissolved in water or swollen therewith. SOLUTION: A direct drawing type waterless lithography, in order to improve a developing property with water or solution having water as a principal component, contains substance which is dissolved in or swollen with water in a heat sensitive breakdown layer. The substance which is dissolved in or swollen with water is preferably 300% or higher in swelling percentage to water, and further preferably 1000% or over. Through the substance which is dissolved in or swollen with water is not especially limited if only it is dispersed efficiently in a composition of the heat sensitive layer, salt, monomer, oligomer, resin, etc., are preferable. By containing substance which is dissolved in or swollen with water in the heat sensitive layer, a developing property and a plate checking property owing to the solution having water as principal component are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterless lithographic printing plate precursor capable of printing without using dampening water, and more particularly to a direct drawing type waterless lithographic printing plate which can be directly made by laser light. It concerns the original.

[0002]

2. Description of the Related Art Direct plate making, in which an offset printing plate is produced directly from an original without using a plate making film, is simple, does not require skill, is quick in obtaining a printing plate in a short time, Utilizing features such as rationality that can be selected according to quality and cost from the system,
In addition to the light printing industry, it has begun to enter the general offset printing and gravure printing fields.

[0003] In recent years, new types of various lithographic printing materials have been developed with the rapid progress of output systems such as prepress systems, imagesetters, and laser printers.

[0004] These lithographic printing plates can be classified according to plate-making methods, such as a method of irradiating a laser beam, a method of writing with a thermal head, a method of partially applying a voltage with a pin electrode, an ink repelling layer or an ink coating with an ink jet. Examples include a method of forming a layer. Above all, the method using laser light is superior to other methods in terms of resolution and plate making speed, and there are many types.

[0005] Lithographic printing plates using this laser beam are further classified into two types: a photon mode type by photoreaction and a heat mode type by which photothermal conversion is performed to cause a thermal reaction.

The photon mode type includes (1) a high-sensitivity PS plate using a photopolymer, (2) an electrophotographic lithographic plate using an organic photoconductor and zinc oxide, (3) a silver salt lithographic plate, and (4) a silver salt composite. Method lithography (5) Direct drawing master and the like, and the heat mode type includes (6) Thermal destruction method lithography.

However, the method (1) uses an argon ion laser mainly as a laser light source, so that the apparatus becomes large, and the printing plate uses a high-sensitivity photopolymer. There is a drawback that care must be taken and the storage stability tends to decrease.

The electrophotographic lithographic plate (2) has the advantage that it can be handled in a bright room, but the dark decay becomes large between 2 and 5 minutes after charging of the photosensitive layer, so that the exposure and development treatment is performed in a short time after charging. Therefore, it is difficult to output a large format with high resolution.

In the silver salt method (3), printing plates corresponding to lasers of various wavelengths have been developed. However, there is a problem that silver waste liquid comes out, and the sensitivity is high. There is also a problem that requires attention.

In the silver halide composite lithographic plate (4), a high-sensitivity silver halide emulsion layer is exposed on a photosensitive layer with an argon ion laser, developed, and then exposed and developed with ultraviolet rays using the exposed layer as a mask. . However, since this printing plate has two exposure and development steps, there is a problem that the processing of the printing plate becomes complicated.

The direct drawing master of (5) does not directly write on a printing plate with a laser, but transfers a toner image formed by a laser printer onto a printing plate as an ink-coated portion. However, the resolution of the printing plate is inferior to other methods.

For the above photon mode type,
The thermal destruction method (6) has the advantage that it can be handled in a bright room, and has recently become useful due to the rapid progress of the output of the semiconductor laser serving as a light source and the rapid progress of the output of the semiconductor laser serving as a light source. Sex is being reviewed.

For example, US Pat. No. 5,379,698 describes a direct-drawing waterless lithographic printing plate using a metal thin film as a heat-sensitive layer. However, the sensitivity of the printing plate is poor because the metal thin film itself transmits laser light. There was a problem. For this reason, in order to increase the absorptance of laser light, an antireflection layer must be provided, and the coating process is further increased,
The consequences are costly.

Further, Japanese Patent Application Laid-Open No. 6-199064, USP
No. 5339737, US Pat. No. 5,353,705, EP05
80393, JP-A-6-55723, EP0573
No. 091, US Pat. No. 5,378,580, JP-A-7-17-1
No. 64773 also describes a direct drawing type waterless planographic printing plate precursor using a laser beam as a light source.

The heat-sensitive layer of the printing plate precursor of this thermal destruction method is
For example, carbon black is used as a laser light absorbing compound, nitrocellulose is used as a thermal decomposition compound, and a silicone layer is applied to the surface thereof. The carbon black in the heat-sensitive layer is converted into heat energy by absorbing laser light, and the heat destroys the heat-sensitive layer. Finally, by removing this portion by development, the silicone rubber layer on which the ink is not deposited is simultaneously peeled off, and an image portion on which the ink is deposited is formed. Such a printing plate precursor can be developed with water or a liquid containing water as a main component, but in this case, there is a problem that it is difficult to completely remove the heat-sensitive layer. There is no problem with the performance of the plate itself because the heat-sensitive layer is also coated with ink. However, since the silicone layer is usually colorless and transparent, the pattern formation of the image area is visually checked unless the colored (black) heat-sensitive layer is peeled off. However, there is a disadvantage that the plate inspection is difficult.

[0016]

SUMMARY OF THE INVENTION In order to overcome the drawbacks of the prior art, the present invention provides a direct-drawing type waterless printing plate having improved plate inspection properties by including a substance which dissolves or swells in water in a heat-sensitive layer. To provide a lithographic printing plate.

[0017]

To achieve the above object, the present invention comprises the following constitution.

(1) In a direct-drawing waterless planographic printing plate precursor comprising a heat-sensitive layer and a silicone rubber layer sequentially laminated on a substrate, the heat-sensitive layer contains a light-to-heat conversion substance and a substance which dissolves or swells in water. A direct drawing type waterless planographic printing plate precursor characterized by the following.

(2) The substance that dissolves or swells in water is
The direct-drawing waterless planographic printing plate precursor as described in (1), which is at least one substance selected from a salt, a monomer, an oligomer, and a resin.

(3) The direct drawing type waterless planographic printing plate precursor as described in (2), wherein the substance which dissolves or swells in water has a dissolution or swelling ratio to water of 300% or more.

(4) The composition according to (1) to (3), wherein the content of the substance which dissolves or swells in water in the heat-sensitive layer is 10 to 40% by weight based on the whole heat-sensitive layer composition. A direct drawing type waterless lithographic printing plate precursor.

(5) The direct-drawing waterless planographic printing plate precursor as described in any one of (1) to (4), wherein the heat-sensitive layer contains nitrocellulose.

(6) The direct-drawing waterless planographic printing plate precursor as described in any one of (1) to (5), wherein the heat-sensitive layer has a crosslinked structure.

(7) Waterless lithographic printing obtained by exposing the direct drawing type waterless lithographic printing plate precursor according to any one of (1) to (6) and developing with water or a liquid containing water as a main component. Edition.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the direct drawing type means that an image is formed directly from a recording head on a printing plate without using a negative or positive film at the time of exposure.

Next, the direct drawing type waterless planographic printing plate of the present invention will be described. The direct drawing type waterless lithographic plate of the present invention is a heat-sensitive destruction layer after exposure, for the purpose of improving the developability with water or a liquid containing water as a main component, a substance which dissolves or swells in water in the heat-sensitive destruction layer. It is necessary to contain it.

The substance that dissolves or swells in water preferably has a swelling ratio to water (hereinafter referred to as a water swelling ratio) of 300% or more, and more preferably has a dissolution or water swelling ratio of 1000% or more.

The water swelling ratio in the present invention is calculated according to the following method.

Water swelling ratio (%) = (MWET−MDRY) × 100 / MDRY MDRY: Weight of target substance in dry state MWET: Weight of target substance after immersion in purified water at 25 ° C. for 24 hours The substance that dissolves or swells in water is not particularly limited as long as it is well dispersed in the composition of the heat-sensitive layer, but salts, monomers, oligomers, resins, and the like are preferably used. Specific examples of these substances that dissolve or swell in water are shown below, but the present invention is not limited thereto.

(1) Natural proteins At least one protein selected from casein, gelatin, soy protein, albumin and the like. Specific examples include milk casein, acid casein, rennet casein, ammonia casein, caricasein, borax casein, glue, gelatin, gluten, soy lecithin, soy protein, collagen and the like.

(2) Alginates Ammonium alginate, potassium alginate, sodium alginate and the like can be mentioned.

(3) Starches Starch alone or one obtained by graft polymerization of starch and a synthetic monomer such as acrylic acid.

(4) Cellulose Cellulose alone or grafted with a synthetic monomer such as acrylic acid. Specific examples include carboxylated methylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and xanthate cellulose.

(5) Hyaluronic acids JP-B-61-8083, JP-A-58-56692
And natural polysaccharide polymers as disclosed in JP-A No. 60-49797 and JP-A-60-49797.

(6) Polyvinyl alcohols Polyvinyl alcohol alone or methyl acrylate
And saponified vinyl acetate copolymer.

(7) Acrylates α, β-unsaturated compounds having at least one group such as a carboxyl group, a carboxylic acid group, a carboxylic acid salt, a carboxylic acid amide, a carboxylic acid imide, or a carboxylic anhydride in the molecule. Monomer, polymer or crosslinked product.

Specific examples of the α, β-unsaturated compound include acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, maleic acid, maleic amide, maleic imide, itaconic acid, croton Acid, fumaric acid, mesaconic acid and the like. These monomers can be subjected to radical polymerization by a known method to obtain a desired polymer or copolymer. In addition, these polymers or copolymers can be made more hydrophilic by reacting with compounds such as alkali metal or alkaline earth metal hydroxides, oxides or carbonates, ammonia, and amines. it can.

(8) Hydrophilic epoxy compound sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate Glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, phenol ethylene oxide added glycidyl ether, lauryl alcohol ethylene oxide added Glycidyl ether, adipine Acid diglycidyl ester and the like.

(9) Water-soluble acrylates Ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, dipropylene glycol Examples thereof include diacrylate, dipropylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, and a reaction product of p-xylylenediamine and glycidyl methacrylate.

Among the above substances which dissolve or swell in water, examples of the substance which is a salt include substances obtained by reacting the substances (2), (6) and (7) with alkaline earth metals. As the monomer and oligomer, (2), (7),
(8) and (9). Examples of the resin include the substances (1), (3), (4), (5), (6) and (7).

Among these hydrophilic compounds, especially resins and crosslinkable monomers and oligomers also have a use as a binder, and it is not necessary to include another binder in the heat-sensitive layer. preferable.

The content of the hydrophilic compound in the heat-sensitive layer is preferably from 10 to 40% by weight. When the content is 10% by weight or less, the intended effect of improving the developing property cannot be obtained,
If the content is 40% by weight or more, the unexposed portion of the heat-sensitive layer which should remain after development swells and is easily peeled off, which is not preferable.

It is important that the heat-sensitive layer used in the present invention absorbs laser light efficiently and is easily decomposed by the heat. For this purpose, it is important to include a light-to-heat conversion substance and a thermally decomposable compound in the heat-sensitive layer.

The photothermal conversion material is not particularly limited as long as it can absorb light and convert it into heat. For example, black pigments such as carbon black, aniline black and cyanine black, phthalocyanine, Phthalocyanine-based green pigment, carbon graphite, iron powder, diamine-based metal complex, dithiol-based metal complex, phenolthiol-based metal complex, mercaptophenol-based metal complex, aryl aluminum metal salts, water-containing inorganic compounds, copper sulfate, chromium sulfide Metal oxides such as titanium oxide, vanadium oxide, manganese oxide, iron oxide, cobalt oxide, and tungsten oxide; hydroxides and sulfates of these metals; and bismuth, tin, tellurium, iron, and aluminum. It is preferable to add an additive such as metal powder.

Of these, carbon black is preferred from the viewpoints of light-to-heat conversion, economy and handling.

In addition to the above substances, dyes that absorb infrared or near-infrared rays are also preferably used as photothermal conversion substances.

As these dyes, 400 nm to 1200
Any dye having a maximum absorption wavelength in the range of nm can be used. Preferred dyes include those for electronics,
Recording dyes cyanine, phthalocyanine, phthalocyanine metal complex, naphthalocyanine, naphthalocyanine metal complex, dithiol metal complex, naphthoquinone, anthraquinone, indophenol, indoaniline, pyrylium, thiopyrylium , Squarylium, croconium, diphenylmethane,
Triphenylmethane, triphenylmethanephthalide, triallylmethane, phenothiazine, phenoxazine, fluoran, thiofluorane, xanthene, indolylphthalide, spiropyran, azaphthalide, chromenopyrazole, Leuco auramine, rhodamine lactam, quinazoline, diazaxanthene, bislactone, fluorenone, monoazo, ketone imine, diazo, methine, oxazine, nigrosine, bisazo, bisazostilbene, bis Azooxadiazole, bisazofluorenone, bisazohydroxyperinone, azochrome complex, trisazotriphenylamine, thioindigo, perylene, nitroso, 1: 2 type metal complex, intermolecular CT System, quinoline Quinophthalone-based, fluid-based acid dyes, basic dyes, pigments, oil-soluble dyes, triphenylmethane-based leuco dyes, cationic dyes, azo-based disperse dyes, benzothiopyran-based spiropyrans, 3,9-dibromoanthanthrone, indanth Ron, phenolphthalein, sulfophthalein, ethyl violet,
Methyl orange, fluorescein, methyl viologen, methylene blue, dimrosbetaine and the like can be mentioned.

Among these, dyes for electronics and recording, having a maximum absorption wavelength of 700 nm to 900 n
m, cyanine-based dye, azurenium-based dye, squarylium-based dye, croconium-based dye, azo-based disperse dye, bisazostilbene-based dye, naphthoquinone-based dye, anthraquinone-based dye, perylene-based dye, phthalocyanine-based dye, na Phthalocyanine metal complex dyes,
Black dyes such as dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, benzothiopyran spiropyrans, and nigrosine dyes are preferably used.

Further, among these dyes, those having a large molar absorbance coefficient are preferably used. Specifically, ε = 1 × 10 4 or more is preferable, and 1 × 1 is more preferable.
05 or more. This is because if ε is smaller than 1 × 10 4, the effect of improving sensitivity is hardly exhibited.

These light-to-heat converting substances alone have an effect of improving sensitivity, but the sensitivity can be further improved by using two or more kinds in combination.

The content of these light-to-heat converting substances is preferably from 2 to 70% by weight, more preferably from 5 to 60% by weight, based on the total heat-sensitive layer composition. When the amount is less than 2% by weight, the effect of improving sensitivity is not seen, and when the amount is more than 70% by weight, the printing durability of the printing plate tends to decrease.

As the thermally decomposable compound, nitro compounds such as ammonium nitrate, potassium nitrate, sodium nitrate, nitrocellulose and the like, organic peroxides, azo compounds, diazo compounds and hydrazine derivatives are preferably used.

Among them, nitrocellulose is a polymer, and therefore has a suitable viscosity in a solution state, and has a hydroxyl group in the molecule, so that it has an adhesive property with a silicone rubber layer. It is particularly preferable because it becomes favorable. The nitrocellulose used here is not intended for explosives, but is preferably industrial nitrocellulose.

The content of these nitrocellulose is preferably from 10 to 80% by weight, more preferably from 20 to 60% by weight, based on the total heat-sensitive layer composition. If the content is less than 10% by weight, the sensitivity of the printing plate will decrease, and if it is more than 80% by weight, the solvent resistance of the printing plate will tend to decrease.

In addition to the above components, it is necessary to include a crosslinking agent in the heat-sensitive layer in order to impart form retention, solvent resistance and printing durability as a printing plate.

As a cross-linking method, a thermal cross-linking type in which a cross-linking reaction proceeds by heating is generally used.

The polyfunctional crosslinking agent used to introduce the crosslinking structure includes a polyfunctional isocyanate compound or a polyfunctional epoxy compound, a urea compound, an amine compound, a hydroxyl group-containing compound, a carboxylic acid compound, and a thiol compound. Combinations with compounds are mentioned.

However, when a polyfunctional isocyanate compound is used, since the reaction is not completed in a short time, it is necessary to cure at a high temperature.
Since it is 80 ° C., it cannot be cured at a higher temperature.

For this reason, the reaction gradually proceeds even after the production of the printing plate, which may adversely affect the developability of the printing plate.

Therefore, as a crosslinking method, a combination of a polyfunctional epoxy compound, an amine compound, a hydroxyl group-containing compound, a carboxylic acid compound, and a thiol compound is preferable.

Examples of the polyfunctional epoxy compound include bisphenol A epoxy resin, bisphenol F epoxy resin, and glycidyl ether epoxy resin.

Examples of the amine compound include a butylated urea resin, a butylated melamine resin, a butylated benzoguanamine resin, a butylated urea melamine cocondensation resin, an aminoalkyd resin, an iso-butylated melamine resin, a methylated meminin resin, and hexamethoxy. Methylol melamine, methylated benzoguanamine resin, butylated benzoguanamine resin, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, metaxylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, isophorone Diamine and the like.

Examples of the amide compounds include polyamide curing agents and dicyandiamide used as curing agents for epoxy resins. Examples of the hydroxyl group-containing compounds include phenol resins and polyhydric alcohols. Examples of the thiol compounds include polyhydric alcohols. And thiols.

As the carboxylic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, dodecynylsuccinic acid, pyromellitic acid, chlorenic acid, maleic acid, fumaric acid and anhydrides thereof are preferably used.

In these cases, quaternary ammonium salts, KOH and SnCl are used as catalysts for accelerating the reaction.
It is preferable to use a known catalyst such as 4, Zn (BF4) 2, or an imidazole compound.

Among the above cross-linking agents, a combination of a polyfunctional epoxy compound and an amine compound is more preferable from the viewpoint of curing speed and handleability. It is more preferable to use a water-soluble epoxy resin from the viewpoint of economical viewpoint and handleability.

Further, a polyfunctional crosslinking agent having an organic silyl group or an amine group-containing monomer can be preferably used.

The crosslinking can be carried out not by heat but by light. The photo-crosslinking type requires that the object sufficiently transmit light, but can be cured in a shorter time and at a lower temperature than the thermal cross-linking type.

As a method capable of forming a crosslinked structure by light, a method of crosslinking a polymer by light irradiation, a method of crosslinking by a polymerization reaction by light irradiation, an acid or
Examples include a method using a compound that generates a base, but the present invention is not limited thereto.

As a method of crosslinking a polymer by light irradiation, a method of crosslinking a polymer such as polyvinyl alcohol, casein, gelatin, polyvinylpyrrolidone with a compound having a dichromate, a diazonium salt, an azide group, or the like, or a method of bisazide compound Natural rubber,
Cross-linking polymers such as polyisoprene and polybutadiene, cross-linking polymers by including photodimerization type group, chloromethyl group, azidomethyl group, dithioalbamate group, thiazole group, etc. in the structure of the polymer itself Is mentioned.

As a method of crosslinking by polymerization reaction by light irradiation, a method of photo-radical polymerization using a combination of a compound having an acryloyl group, a methacryloyl group, etc. and a substance capable of generating a radical by light, an acryloyl group,
Methacryloyl group, a method by photoaddition polymerization by combining a compound having a carbon-carbon unsaturated group such as a vinyl group with a thiol and a substance that generates a radical by light, having an epoxy group, an acryloyl group, a methacryloyl group, a vinyl group, etc. A method by photocation polymerization using a combination of a compound and a substance that generates a cationic species by light is exemplified.

As a method of using a compound which generates an acid or a base upon irradiation with light, a phenol resin, an epoxy resin,
A method of irradiating a composition containing an amino resin alone or a mixture of two or more thereof with a photoacid generator or a photoamine generator, followed by heating and thermosetting is used.

The content of these polyfunctional crosslinking agents is preferably from 1 to 50% by weight, more preferably from 3 to 40% by weight, based on the whole heat-sensitive layer composition. When the amount is less than 1% by weight, the solvent resistance of the printing plate tends to decrease. When the amount is more than 50% by weight, the printing plate becomes hard and the printing durability tends to decrease.

The heat-sensitive layer preferably contains a binder polymer for the purpose of improving printing durability and storage stability.
Polyurethane resin, phenol resin, acrylic resin, alkyd resin, polyester resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, polyvinyl butyral resin, ethylene-vinyl acetate copolymer, polycarbonate resin, polyacrylonitrile-butadiene copolymer ,
Polyether resin, polyether sulfone resin, milk casein, gelatin, carboxymethyl cellulose, cellulose acetate, cellulose propyl acetate,
Cellulose derivatives such as cellulose butyl acetate, cellulose triacetate, hydroxypropyl cellulose ether, ethyl cellulose ether, cellulose phosphate, polyvinyl acetate, polystyrene, polystyrene-acrylonitrile copolymer, polysulfone, polyphenylene oxide, polyvinyl alcohol-acetal copolymer, polyvinyl acetal , Polyvinyl alcohol-polyacetal copolymer, polyvinyl alcohol-polybutyral copolymer, polyvinyl benzal,
Polyvinyl alcohol, ethylene-maleic anhydride copolymer, chlorinated polyethylene, chlorinated polyolefins such as chlorinated polypropylene and the like, among which cellulose derivatives such as cellulose acetate, polyvinyl chloride-vinyl acetate copolymer and the like Chlorine-containing copolymers, polyurethane end resins, and acrylic resins are preferably used. Among them, the use of a water-soluble binder is more preferable from the viewpoint of economical viewpoint and handleability.

In addition to the above-mentioned thermally decomposable compounds, polyacetylene, polyaniline and the like, which are known as conductive polymers, are also preferably used.

The content of these binders is preferably from 10 to 60% by weight, more preferably from 20 to 50% by weight, based on the total heat-sensitive layer composition. If the content is less than 10%, the printing durability tends to decrease, and if it exceeds 60% by weight, the sensitivity tends to decrease.

Further, in the heat-sensitive layer, a preservative, an antihalation dye, an antifoaming agent, an antistatic agent, a dispersant, an emulsifier,
An additive such as a surfactant may be appropriately contained.

In particular, it is preferable to add a fluorinated surfactant in order to improve coatability. The content of these additives is usually 10% by weight or less based on the total heat-sensitive layer composition.

When an addition type silicone rubber is used for the silicone rubber layer, a compound having an ethylenically unsaturated double bond can be added for the purpose of improving the adhesion between the heat-sensitive layer and the silicone rubber layer. Examples of the compound having an ethylenically unsaturated double bond include the following compounds, and among them, epoxy acrylates are particularly preferable. The amount of the compound having an ethylenically unsaturated double bond to be used is preferably 0.5 to 30% by weight based on the total composition of the heat-sensitive rupture layer.

(1) Esterified product of polyfunctional hydroxyl group-containing compound and acrylic acid or methacrylic acid.

Examples of the polyfunctional hydroxyl group-containing compound include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, hydroquinone, dihydroxyanthraquinone, bisphenol A, bisphenol S, resole resin, pyrogallol acetone resin,
Examples include hydroxystyrene copolymer, glycerin, pentaerythritol, dipentaerythritol, trimethylolpropane, polyvinyl alcohol, cellulose, and derivatives thereof, and polymers and copolymers of hydroxyacrylate and hydroxymethacrylate. The target compound can be obtained by subjecting these polyfunctional hydroxyl group-containing compounds to an acrylic acid or methacrylic acid esterification reaction by a known method. At this time, it is necessary to carry out the reaction at a ratio containing two or more ethylenically unsaturated groups in one molecule.

(2) Epoxy acrylates obtained by reacting an epoxy compound with acrylic acid, methacrylic acid, glycidyl acrylate, or glycidyl methacrylate.

Specific examples of the epoxy compound include compounds obtained by reacting the hydroxyl-containing compound described in the section (1) with epihalohydrin.

In addition, those obtained by adding ethylene oxide or propylene oxide to each of the hydroxyl groups of the above-mentioned hydroxyl group-containing compound can also be used.

The desired epoxy acrylates can be obtained by reacting these epoxy compounds with acrylic acid, methacrylic acid or glycidyl acrylate or glycidyl methacrylate in a known manner.

(3) A compound obtained by reacting an amine compound with glycidyl acrylate, glycidyl methacrylate or acrylic acid chloride or methacrylic acid chloride.

As the amine compound, octylamine,
Monovalent amine compounds such as laurylamine, dioxyethylenediamine, trioxyethylenediamine, tetraoxyethylenediamine, pentaoxyethylenediamine, hexaoxyethylenediamine, heptaoxyethylenediamine, octaoxyethylenediamine, nonaoxyethylenediamine, monooxypropylenediamine, dioxypropylene Diamine, trioxypropylenediamine, tetraoxypropylenediamine, pentaoxypropylenediamine, hexaoxypropylenediamine, heptaoxypropylenediamine, okitaoxypropylenediamine, nonaoxypropylenediamine, polymethylenediamine, polyetherdiamine, diethylenetriamine, triethylenetetramine , Tetraethylpentamine, etc. Aliphatic polyamine compound and, m
-Xylylenediamine, p-xylylenediamine, m-
Phenylenediamine, diaminodiphenyl ether, benzidine, 4,4′-bis (o-toluidine), 4,
4'-thiodianiline, o-phenylenediamine, dianisidine, 4-chloro-o-phenylenediamine, 4-
And polyamine compounds such as methoxy-6-methyl-m-phenylenediamine. The target compound can be obtained by reacting these amine compounds with glycidyl acrylate, glycidyl methacrylate or acrylic acid chloride or methacrylic acid chloride by a known method.

(4) A compound obtained by reacting a compound having a carboxyl group with glycidyl acrylate and glycidyl methacrylate.

Examples of the carboxyl group-containing compound include malonic acid, succinic acid, malic acid, thiomalic acid, racemic acid,
Examples thereof include citric acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, dimer acid, trimellitic acid, and carboxy-modified unvulcanized rubber.

The compound having a carboxyl group can be reacted with glycidyl acrylate or glycidyl methacrylate by a known method to obtain a desired compound.

(5) Urethane acrylates Glycerin diacrylate isophorone diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer and the like can be mentioned.

The compounds having two or more ethylenically unsaturated double bonds in one molecule can be used alone or in combination of two or more.

Further, in some cases, in order to improve the adhesion to the additional silicone rubber layer as the upper layer, hydrophobic silica whose surface is treated with a silane coupling agent containing a (meth) acryloyl group or an allyl group is used. The powder may be added in an amount of 20% by weight or less based on the total heat-sensitive layer composition.

The composition for forming the heat-sensitive layer is as follows:
Dimethylformamide, methyl ethyl ketone, methyl isobutyl ketone, dioxane, toluene, xylene, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether , Acetone, methanol, ethanol, cyclopentanol, cyclohexanol, diacetone alcohol, benzyl alcohol, butyl butyrate,
It is prepared as a composition solution by dissolving in a suitable organic solvent such as ethyl lactate. Such a composition solution is uniformly applied on a substrate and thermally cured at a required temperature for a required time to form a heat-sensitive layer.

These heat curing must be carried out at a temperature within a range in which nitrocellulose, which is a thermally decomposable compound, is not decomposed, usually at a temperature of 180 ° C. or lower. For this reason, it is preferable to use the above-mentioned catalyst in combination.

The thickness of the heat-sensitive layer is preferably from 0.1 g / m 2 to 10 g / m 2, more preferably 0.2 g / m 2.
From 5 g / m2. When the film thickness is less than 0.1 g / m 2, the printing durability tends to decrease, and when the film thickness is more than 10 g / m 2, the heat-sensitive layer is not completely decomposed during exposure. preferable.

As the substrate of the printing plate, a dimensionally stable plate is used. Such dimensionally stable plate-like objects include those conventionally used as a substrate for a printing plate, and they can be suitably used. Such substrates include paper, plastics (eg, polyethylene, polypropylene, polystyrene, etc.), metal plates such as zinc, copper, etc., such as cellulose, carboxymethylcellulose, cellulose acetate, polyethylene,
Examples include a plastic film such as polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetate, and the like, and a paper or plastic film on which a metal is laminated or vapor-deposited as described above. Among these substrates, an aluminum plate is particularly preferable because it has excellent dimensional stability and is inexpensive. Further, a polyethylene terephthalate film used as a substrate for light printing is also preferably used.

The direct drawing type waterless lithographic printing plate used in the present invention may use a primer layer in order to strengthen the adhesion between the substrate and the heat-sensitive layer. The primer layer of the direct drawing type waterless planographic printing plate precursor used in the present invention needs to satisfy the following conditions. That is, the substrate and the heat-sensitive layer are well adhered to each other, are stable over time, and have good resistance to the solvent of the developing solution. As those satisfying such conditions, in addition to those containing an epoxy resin as described in JP-B-61-54219, polyurethane resins, epoxy resins, phenol resins, acrylic resins, alkyd resins, polyester resins, polyamide resins, melanin Resin, urea resin, benzoguanamine resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral resin, polyacrylonitrile-butadiene copolymer, resole resin, polyether resin, epoxy phenol urea resin, polyether sulfone resin, milk casein,
Gelatin or the like can be used. These resins can be used alone or in combination of two or more.

A composition similar to that of the heat-sensitive layer may be cured by light or heat.

Of these, it is preferable to use a polyurethane resin, a polyester resin, an acrylic resin, an epoxy resin, a urea resin, an epoxyphenol urea resin, a resole resin, or the like alone or as a mixture of two or more.

The content of these polymers is preferably from 20 to 98% by weight, more preferably from 40 to 95% by weight, based on the total primer layer composition.

It is preferable that a crosslinking agent is contained in the primer layer in order to impart solvent resistance.

As the crosslinking agent, a combination of the above resins, for example, an epoxy resin and an amino resin (a urea resin, a melamine resin, a benzoguanamine resin, etc.) can be used, but a combination of an isocyanate compound and a hydroxyl group-containing compound can be used. It is.

As such isocyanate compounds, for example, paraphenylene diisocyanate, 2,4-
Or 2,6-toluylene diisocyanate (TD
I), 4,4-diphenylmethane diisocyanate (M
DI), tolylene diisocyanate (TODI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate, cyclohexane diisocyanate,
Meta-xylylene diisocyanate (MXDI), lysine diisocyanate (LDI) (also known as 2,6-diisocyanatomethylcaprolate), hydrogenated MDI (also known as 4,
4'-methylenebis (cyclohexylisocyanate)), hydrogenated TDI (also known as methylcyclohexane 2,
4 (2,6) -diisocyanate), hydrogenated XDI (also known as 1,3- (isocyanatomethyl) cyclohexane), isophorone diisocyanate (IPI), diphenyl ether diisocyanate, trimethylhexamethylene diisocyanate (TMDI), tetramethyl xylylene diisocyanate, polymethyl Methylenephenyl isocyanate, dimer acid diisocyanate (DDI), triphenylmethane triisocyanate, tris (isocyanatephenyl) thiophosphate, tetramethylxylylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8- Diisocyanate-4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, bicyclo And the like heptane triisocyanate, high alcohol adduct polyisocyanates,
Alternatively, a polymer of a polyisocyanate is used.

Blocked isocyanates obtained by blocking the above-mentioned isocyanate compounds with methyl ethyl ketoxime, phenol, ε-caprolactam and the like can also be used.

Examples of the compound having a hydroxyl group that can react with these isocyanate compounds include an epoxy resin, a phenol resin, a resole resin, a hydroxyl group-containing polyurethane, an acrylic resin, and a hydroxyl group-containing monomer or oligomer.

The content of these crosslinking agents is preferably from 20 to 70% by weight, more preferably from 30 to 60% by weight, based on the total primer layer composition.

It is also optional to add an acid or an organotin compound as a catalyst for accelerating these reactions, or to add a surfactant for the purpose of improving coating properties.

Since the primer layer is exposed in the exposed area of the printing plate to form an image area, it is preferable to add an additive such as a dye or a pigment to the primer layer to improve the plate inspection property. In this case, any dyes and pigments can be used as long as they have a different hue from that of the heat-sensitive layer, but green, blue and purple dyes and pigments are preferable.

The composition for forming the above-mentioned primer layer is obtained as a composition solution by dissolving in a suitable organic solvent such as dimethylformamide, methyl ethyl ketone, methyl isobutyl ketone, dioxane and the like. The primer layer is formed by uniformly applying such a composition solution on a substrate and heating it at a required temperature for a required time.

The thickness of the primer layer is 0.5
５０50 g / m 2, preferably 1-10 g
/ M2. When the thickness is less than 0.5 g / m 2, there is an effect of blocking morphological defects and chemical adverse effects on the substrate surface,
If the thickness is more than 50 g / m 2, it is disadvantageous from an economic viewpoint, so the above range is preferable.

As the uppermost silicone rubber layer, any conventional waterless planographic silicone composition can be used.

Such a silicone rubber layer is obtained by sparsely cross-linking a linear organopolysiloxane (preferably dimethylpolysiloxane). A typical silicone rubber layer is represented by the following formula (I). It has a repeating unit as shown below.

[0114]

Embedded image (Here, n is an integer of 2 or more. R has 1 to 10 carbon atoms.)
Alkyl, aryl, or cyanoalkyl group. Preferably, 40% or less of the whole R is vinyl, phenyl, vinyl halide, or halogenated phenyl, and 60% or more of R is a methyl group. It has at least one or more hydroxyl groups in the molecular chain in the form of a chain terminal or side chain. In the case of the silicone rubber layer applied to the printing plate of the present invention, a silicone rubber (R
TV, LTV silicone rubber).
As such a silicone rubber, those in which a part of R of the organopolysiloxane chain is substituted by H can be used, and usually, by condensation of terminal groups represented by (II) and (III) and (IV), Crosslinked. In some cases, an excess of a crosslinking agent may be present.

[0115]

Embedded image

Embedded image

Embedded image (Where R is the same as R described in formula (I),
1, R2 is a monovalent lower alkyl group, and Ac is an acetyl group. Examples of the silicone rubber which performs such condensation type crosslinking include metal carboxylate salts such as tin, zinc, lead, calcium, and manganese, for example, dibutyltin laurate, tin (II)
A catalyst such as octoate, naphthenate, or chloroplatinic acid is added.

In addition to these compositions, a known adhesion-imparting agent such as alkenyl trialkoxysilane may be added, or a hydroxyl group-containing organopolysiloxane which is a composition of a condensation type silicone rubber layer, a hydrolyzable functional group, or the like. The addition of a silane (or siloxane) is optional, and a known filler such as silica is optionally added for the purpose of improving rubber strength.

Further, in the present invention, it is possible to use an addition type silicone rubber in addition to the above-mentioned condensation type silicone rubber.

As the addition type silicone rubber, those obtained by crosslinking and curing a hydrogen polysiloxane having a Si—H bond and a vinyl polysiloxane having a CH ＝ CH bond with a platinum-based catalyst as shown below are preferably used. Can be

(1) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups (preferably vinyl groups) directly bonded to a silicon atom in one molecule. (2) An organopolysiloxane having at least two SiH groups in one molecule. Hydrogenpolysiloxane 0.1 to 1000 parts by weight (3) Addition catalyst 0.00001 to 10 parts by weight The alkenyl group of the component (1) may be located at the terminal of the molecular chain or in the middle, and may be an organic compound other than the alkenyl group. The group is a substituted or unsubstituted alkyl group or aryl group. Component (1) may have a trace amount of hydroxyl groups. Ingredient (2)
Reacts with the component (1) to form a silicone rubber layer, which plays a role in providing adhesion to the heat-sensitive layer. The hydrogen group of the component (2) may be at the terminal of the molecular chain or at the middle, and the organic group other than hydrogen is selected from those similar to the component (1). It is preferable that 60% or more of the organic groups of the component (1) and the component (2) are methyl groups as a whole in view of improvement of ink repellency. The molecular structure of the components (1) and (2) may be any of linear, cyclic and branched, and it is preferable that at least one of the molecular weights exceeds 1,000 from the viewpoint of rubber physical properties. Preferably has a molecular weight of more than 1,000. Examples of the component (1) include α, ω-divinylpolydimethylsiloxane, a (methylvinylsiloxane) (dimethylsiloxane) copolymer having a methyl group at both terminals, and the like. As the component (2), a hydrogen group having a hydrogen group at both terminals. Polydimethylsiloxane, α, ω-
Examples thereof include dimethyl polymethyl hydrogen siloxane, (methyl hydrogen siloxane) (dimethyl siloxane) copolymer having both terminal methyl groups, and cyclic polymethyl hydrogen siloxane. The addition catalyst of the component (3) is arbitrarily selected from known catalysts, and is particularly preferably a platinum-based compound, and examples thereof include simple platinum, platinum chloride, chloroplatinic acid, and olefin-coordinated platinum. In order to control the curing rate of these compositions, organopolysiloxanes containing vinyl groups such as tetracyclo (methylvinyl) siloxane, alcohols containing carbon-carbon triple bonds, acetone, methyl ethyl ketone, methanol, ethanol, propylene glycol monomethyl ether It is also possible to add a crosslinking inhibitor such as. These compositions have the characteristic that an addition reaction occurs when the three components are mixed and curing starts, but the curing rate rapidly increases as the reaction temperature increases. Therefore, for the purpose of extending the pot life until rubberization of the composition, and shortening the curing time on the heat-sensitive layer, the curing conditions of the composition, the substrate, a temperature condition in a range that does not change the properties of the heat-sensitive layer, In addition, it is preferable to keep the temperature at a high temperature until it is completely cured, from the viewpoint of the stability of the adhesive force with the thermosensitive layer.

In addition to these compositions, it is also effective to add the above-mentioned known silane coupling agents for the purpose of improving the adhesion to the heat-sensitive layer.

In addition to the above, it is optional to add a hydroxyl group-containing organopolysiloxane and a hydrolyzable functional group-containing silane (or siloxane), which are compositions of the condensation type silicone rubber layer, and to improve the rubber strength. It is optional to add a known filler such as silica for the purpose.

The thickness of these silicone rubber layers is 0.5
~ 50 g / m2, more preferably 0.5 ~
10 g / m2. When the film thickness is less than 0.5 g / m 2, the ink repellency of the printing plate tends to decrease, and
If it is larger than g / m 2, it is disadvantageous from an economic point of view.

For the purpose of protecting the silicone rubber layer on the surface of the waterless planographic printing plate precursor configured as described above, a plain or irregularly treated thin protective film is laminated on the surface of the silicone rubber layer. It is also possible to form a polymer coating film which can be dissolved in a developing solvent described in JP-A-5-323588.

In particular, when a protective film is laminated, laser exposure is performed from above the protective film, and then the protective film is peeled off to form a pattern on the printing plate. It is also possible to form.

A method for producing a waterless planographic printing plate according to the present invention will be described. Using a normal coater such as a reverse roll coater, an air knife coater, or a Meyer bar coater, or a spin coater such as a wheyer, apply the primer layer composition to the substrate as needed.
After thermosetting at 0 ° C. for several minutes, a heat-sensitive layer composition coating liquid is applied,
The composition is heat-cured or light-cured at 50 to 180 ° C. for several minutes, coated with a silicone rubber layer composition coating solution, and treated at a temperature of 50 to 200 ° C. for several minutes to cure the rubber. Thereafter, a protective film is laminated or a protective layer is formed as necessary.

The thus-obtained direct drawing type waterless planographic printing plate precursor is exposed to a laser beam from the protective film after the protective film is peeled off or from above the protective film.

For the exposure, a laser beam is usually used.
At this time, the light source has a transmission wavelength of 300 nm to 1500.
Ar ion laser, Kr ion laser, He-Ne laser, He-Cd laser, ruby laser, glass laser, semiconductor laser, YAG in the nm range
Laser, titanium sapphire laser, dye laser,
Various lasers such as a nitrogen laser and a metal vapor laser can be used. Among them, a semiconductor laser is preferable because it is downsized due to recent technological progress and is economically more advantageous than other laser light sources.

The direct drawing type waterless lithographic printing plate exposed by the above method is subjected to peeling development or ordinary solvent development if necessary.

Examples of the developer used in the present invention include, for example, water, water obtained by adding the following polar solvent to water, and aliphatic hydrocarbons (hexane, heptane, “Isoper E,
G, H "(brand name of isoparaffin hydrocarbons manufactured by ESSO), gasoline, kerosene, etc.), at least one kind of aromatic hydrocarbons (toluene, xylene, etc.), halogenated hydrocarbons (trichlene, etc.) A solvent obtained by adding at least one of the following polar solvents to a solvent is preferably used.

Alcohols (methanol, ethanol,
Propanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol,
Tripropylene glycol, polypropylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, hexylene glycol, 2-ethyl-1,3
Ethers (ethylene glycol monoethyl ether,
Diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol-2-ethylhexyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl Ethers, dioxane, tetrahydrofuran, etc. Esters (ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, butyl lactate, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.) Carboxylic acid (2-ethyl Butyric acid, caproic acid, caprylic acid, 2-ethylhexanoic acid, capric acid, oleic acid,
(Lauric acid, etc.) It is also possible to freely add a known surfactant to the above developer composition. Further, an alkali agent such as sodium carbonate, monoethanolamine, diethanolamine, diglycolamine, monoglycolamine, triethanolamine, sodium silicate, potassium silicate, potassium hydroxide, sodium borate and the like can be added. .

To these developers, known basic dyes such as crystal violet, Victoria Pure Blue and Astrazone Red, acid dyes and oil-soluble dyes are added, and the image area is dyed simultaneously with the development. Can be.

In the development, the developer can be developed by impregnating a nonwoven fabric, absorbent cotton, cloth, sponge or the like with such a developer and wiping the plate surface.

For development, see JP-A-63-16335.
By using the automatic developing method described in No. 7, the plate can be suitably developed by treating the plate with the above developer and then rubbing the plate with a rotary brush while showering with tap water or the like.

Development can also be performed by spraying hot water or steam onto the plate instead of the above-mentioned developer.

[0135]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 A primer solution having the following composition was applied on a degreased aluminum plate having a thickness of 0.15 mm using a bar coater.
The film was thermally cured at 00 ° C. for 2 minutes, and a primer layer having a thickness of 4 g / m ² was applied.

(A) 90 parts by weight of a polyurethane resin (Samprene LQ-T1331, manufactured by Sanyo Chemical Industries, Ltd.) (b) 35 parts by weight of a block isocyanate (Takenate B830, manufactured by Takeda Pharmaceutical Co., Ltd.) (c) Epoxy Phenol / urea resin (SJ9372, manufactured by Kansai Paint Co., Ltd.) 8 parts by weight (d) dimethylformamide 725 parts by weight Subsequently, the following heat-sensitive layer composition was applied thereon using a bar coater, and then applied at 150 ° C. for 1 minute. Heat cured, film thickness 1g / m
^Two heat sensitive layers were provided.

(A) 30 parts by weight of carbon black (b) 24 parts by weight of nitrocellulose (c) 15 parts by weight of a water-soluble epoxy resin (Denacol EX145, manufactured by Nagase Kasei Co., Ltd.) (d) Amino resin (Uban 2061, Mitsui 14 parts by weight (e) Acrylic ester ("Light Acrylate" 3EG-A, manufactured by Kyoeisha Yushi Kagaku Kogyo KK) 15 parts by weight (f) 100 parts by weight of dimethylformamide (g) 800 parts by weight of methyl cellosolve Subsequently, a silicone rubber layer composition having the following composition was applied using a bar coater, and thermally cured at 170 ° C. for 2 minutes to provide a silicone rubber layer having a thickness of 2 g / m ^2. Was.

(A) 90 parts by weight of vinyl group-containing polysiloxane (b) 8 parts by weight of hydrogen polysiloxane (c) 2 parts by weight of curing retarder (d) 0.2 part by weight of catalyst (e) Adhesive component (DY39- 067) 0.8 parts by weight (f) "Isopar E" (manufactured by Exxon Chemical Co., Ltd.) 1400 parts by weight A 8 μm-thick polyester film "Lumirror" (Toray Industries, Inc.) Was laminated using a calendar roller to obtain a direct-drawing waterless planographic printing plate precursor.

Thereafter, the “Lumirror” of the printing plate precursor was peeled off, and the semiconductor laser (O) was mounted on an XY table.
PC-A001-mmm-FC, output 0.75W, wavelength 780nm, OPTO POWER CORPORATE
ION), beam diameter 20 μm, exposure time 1
Pulse exposure was performed at 0 μs.

Subsequently, the exposed plate was rubbed 30 times with a cotton pad impregnated with water to develop the plate. The optical densities of the unexposed portion (ink repelling portion) and the exposed portion (ink-coated portion) were measured using a Macbeth optical densitometer, and the peeling condition of the heat-sensitive layer in the exposed portion was examined. Table 2 shows the results
Shown in

Comparative Example 1 A plate was prepared in the same manner as in Example 1 except that the water-soluble epoxy resin in the heat-sensitive layer was replaced by Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) which was a water-insoluble epoxy resin. Materials were prepared and evaluated. The results are shown in Table 2. Examples 2 to 4 Table 1 shows the water-soluble epoxy resin in the heat-sensitive layer in Example 1.
A plate material was prepared and evaluated in the same manner except that the substance was dissolved or swelled in water as shown in Table 2 above. Table 2 shows the results.

Although all of the plates exhibited good image reproducibility, as shown in Table 2, the plates containing a water-soluble or water-swellable substance had almost completely peeled off the heat-sensitive layer at the ink-coated portion. It can be seen that the plate without the water-soluble or water-swellable substance did not completely remove the heat-sensitive layer, but had poor plate-detection.

[0144]

[Table 1]

[Table 2]

[0145]

The present invention is directed to a direct-drawing waterless lithographic printing plate in which a heat-sensitive layer contains a substance which dissolves or swells in water, thereby improving the developability and plate inspection properties with a liquid containing water as a main component. A version was obtained.

Claims (7)

[Claims] 1. A direct-drawing waterless lithographic printing plate precursor comprising a heat-sensitive layer and a silicone rubber layer sequentially laminated on a substrate, wherein the heat-sensitive layer contains a light-to-heat conversion substance and a substance which dissolves or swells in water. A direct drawing type waterless planographic printing plate precursor characterized by the following. 2. The direct drawing type waterless lithographic printing plate according to claim 1, wherein the substance that dissolves or swells in water is at least one substance selected from salts, monomers, oligomers, and resins. Original version. 3. The direct drawing type waterless planographic printing plate precursor as claimed in claim 1, wherein the substance which dissolves or swells in water has a dissolution or swelling ratio to water of 300% or more. 4. The direct drawing according to claim 1, wherein the content of the substance which dissolves or swells in water in the heat-sensitive layer is 10 to 40% by weight based on the whole heat-sensitive layer composition. Lithographic printing plate precursor without mold water. 5. The direct drawing type waterless lithographic printing plate precursor according to claim 1, wherein the heat-sensitive layer contains nitrocellulose. 6. The direct-drawing waterless planographic printing plate precursor according to claim 1, wherein the heat-sensitive layer has a crosslinked structure. 7. Production of a waterless planographic printing plate obtained by exposing the direct drawing type waterless planographic printing plate precursor according to any one of claims 1 to 6 and developing with water or a liquid containing water as a main component. Method.