JP2002086940A - Original plate for thermal lithography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for thermal lithography which can be fitted for printing to a press as it is, without being processed, after scanning exposure based on digital signals and which is improved in plate wear. SOLUTION: The original plate for thermal lithography has on an aluminum substrate an ink receiving layer (1) and a hydrophilic layer (2) which contains a colloidal-particle-like oxide or a hydroxide of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and a transition metal, and at least either the ink receiving layer or the hydrophilic layer contains a photothermal conversion agent. The aluminum substrate has an anodized coat of 2 g/m2 or more and a silicate coat of which the amount of deposition of the silicon is 15 mg/m2 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive lithographic printing plate not requiring development. More specifically, an image can be recorded by infrared laser beam scanning exposure based on a digital signal, and the recorded image can be directly mounted on a printing machine and printed without going through a conventional developing process. The present invention relates to a lithographic printing plate that is capable of being excellent in sensitivity, printing start inking property, and printing durability.

[0002]

2. Description of the Related Art Various methods have been proposed for a lithographic printing plate precursor that can be mounted on a printing machine without any processing after exposure and printing can be performed. One of the promising methods is a method using ablation in which a solid-state high-power infrared laser such as a semiconductor laser or a YAG laser is used for exposure, and the exposed portion is heated with a photothermal conversion agent that converts light into heat, thereby causing decomposition and evaporation. It is. That is, a hydrophilic layer is provided on a substrate having a lipophilic ink-receiving surface or a lipophilic ink-receiving layer, and the hydrophilic layer is ablated and removed.

[0003] WO 94/18005 discloses a printing plate in which a crosslinked hydrophilic layer is provided on a lipophilic laser light absorbing layer, and the hydrophilic layer is ablated. The hydrophilic layer is formed by cross-linking polyvinyl alcohol with a hydrolyzate of tetraethoxysilicon and containing titanium dioxide particles to improve the film strength of the hydrophilic layer. This technology improves press life. However, since it is mainly composed of polyvinyl alcohol having a hydrocarbon group and not necessarily having high hydrophilicity, the stain resistance is insufficient, and further improvement is required.

[0004] WO98 / 40212, WO99 /
JP-A-19143 and WO99 / 19144 disclose, on a substrate coated with an ink-receiving layer, a hydrophilic layer mainly composed of a colloid such as silica crosslinked with a crosslinking agent such as aminopropyltriethoxysilane. A lithographic printing plate that can be mounted on a printing press without development is disclosed. The hydrophilic layer has reduced hydrocarbon groups as much as possible to enhance the resistance to printing stains, and improves the printing durability by crosslinking the colloid with a crosslinking agent.

[0005]

However, with the above-mentioned technology, the printing durability is inadequate at several thousand sheets, and the digital direct non-process printing plate utilizing ablation in the prior art is difficult to stain, which is the basic of printing. There was a problem that either the printing durability or the printing durability was impaired.

As a result of various studies, beryllium, magnesium, aluminum, silicon, titanium, beryllium, magnesium, aluminum, silicon, titanium,
It contains a colloid of an oxide or hydroxide of at least one element selected from boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal, a hydrophilic resin, and the like, and the heating unit is a fountain solution for printing. Alternatively, by providing a heat-sensitive lithographic printing plate precursor having a three-dimensionally cross-linked hydrophilic layer which is easily removed by ink and a water-soluble overcoat layer in order, the printing durability and stain resistance of the digital direct unprocessed printing plate are reduced. Have been found to be compatible (see Japanese Patent Application No. 11-247774). However, even in such a heat-sensitive lithographic printing plate, further improvement in printing durability has been demanded.

[0007] Accordingly, it is an object of the present invention to meet the above additional needs. In other words, it is an object of the present invention to provide a heat-sensitive lithographic printing plate which can be directly mounted on a printing machine for printing without performing post-exposure processing, and further has improved printing durability.

[0008]

Means for Solving the Problems The present inventor has found that the above object can be achieved by the following constitution. That is, the present invention is as follows.

1. On an aluminum support, (1) an ink receiving layer, and (2) at least one selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. A heat-sensitive lithographic printing plate having a hydrophilic layer containing a colloidal particulate oxide or hydroxide of an element, wherein at least one of the ink-receiving layer and the hydrophilic layer contains a photothermal conversion agent, A heat-sensitive lithographic printing plate precursor comprising a support having an anodic oxide film of ² g / m ² or more and a silicate film having a silicon adhesion of 15 mg / m ² or more.

[0010] 2. An aluminum support having (1) an ink-receiving layer, (2) a hydrophilic layer as described in 1 above, and (3) a hydrophilic overcoat layer that can be removed on a printing press. At least one of the hydrophilic overcoat layers is a heat-sensitive lithographic printing plate containing a light-to-heat conversion agent, the aluminum support has an anodized film of ² g / m ² or more, and the silicon adhesion amount is 15mg
A heat-sensitive lithographic printing plate having a silicate coating of at least / m ² .

[0011]

Embodiments of the present invention will be described below in detail. The aluminum support used in the present invention is a pure aluminum plate or an alloy plate containing aluminum as a main component and a trace amount of a different element, and further has a plastic laminated on a thin film of aluminum or an aluminum alloy. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of the foreign element in the alloy is at most 10% by weight or less. Further, an aluminum plate from an aluminum ingot using the DC casting method or an aluminum plate from an ingot using the continuous casting method may be used. However, as the aluminum plate applied to the present invention, an aluminum plate of a conventionally known and used material can be appropriately used.

The thickness of the substrate used in the present invention is 0.05 mm to 0.6 mm, preferably 0.1 mm to 0.6 mm.
0.4 mm, particularly preferably 0.15 mm to 0.3 mm
It is.

Prior to anodizing the aluminum plate, it is preferable to roughen the surface. Roughening can increase the surface area and improve the adhesion to the upper layer. The surface roughening treatment of the aluminum plate surface is performed by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of selectively dissolving the surface chemically. It is performed by a method or a combination of two or more of these methods. As a mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used. As a chemical method, a method of immersing in a saturated aqueous solution of an aluminum salt of a mineral acid as described in JP-A-54-31187 is suitable. Further, as an electrochemical surface roughening method, there is a method of carrying out an alternating current or a direct current in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Also, Japanese Patent Application Laid-Open No. 54-6390
No. 2, an electrolytic surface roughening method using a mixed acid can also be used. The surface roughening by the above-mentioned method is performed by using the center line average roughness (Ha) of the aluminum plate surface.
Is preferably applied in the range of 0.3 to 1.0 μm.

The roughened aluminum plate is subjected to an alkali etching treatment with an aqueous solution of potassium hydroxide or sodium hydroxide, if necessary, further neutralized, and then anodized.

As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes forming a porous oxide film can be used. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, sulfamic acid, Benzenesulfonic acid,
Alternatively, their mixed acids are used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Anodizing treatment conditions vary depending on the electrolyte to be used, and thus cannot be specified unconditionally.
80% by weight solution, liquid temperature 5 to 70 ° C, current density 5 to 60
A / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 50 minutes are appropriate. Among these anodizing treatments, in particular, a method of anodizing with high current density in sulfuric acid described in British Patent No. 1,412,768 and US Pat. No. 3,511,661 are described. A method of performing anodic oxidation using phosphoric acid as an electrolytic bath is preferable.

The amount of the oxide film on the aluminum support of the present invention is 2.0 g / m ² or more. More preferably 2.0
６6.0 g / m ² , particularly preferably 2.0-4.0 g
/ M ² . If it is less than 2.0 g / m ² , the effect of increasing printing durability is insufficient.

As the support used in the present invention, a substrate having the above-mentioned surface treatment and having an anodized film may be used.
Alkali metal silicate aqueous solution treatment (hereinafter also referred to as silicate treatment) may be used as it is,
For improvement of heat insulation, etc., if necessary, apply for patent application 2000
The process of enlarging the micropores of the anodic oxide film and the process of sealing the micropores described in Japanese Patent Application No. 65219/2000 and Japanese Patent Application No. 2000-143487 can be appropriately selected and performed.

According to the present invention, a support having an anodic oxide film of ² g / m ² or more is subjected to a silicate treatment as a hydrophilization treatment, and has a silicate film of 15 mg / m ² or more as a silicon deposit. Is the feature. Here, the adhesion amount as silicon is calculated from the silicon amount measured by X-ray fluorescence analysis of the silicate-treated substrate, from the silicon amount measured on the aluminum substrate before the silicate treatment (usually about 1 mg /
m ² ), and converted to the amount per 1 m ² .

By increasing the amount of silicon deposited as in the present invention, the detailed mechanism is unknown, but dot-like printing stains generated when printing is suppressed, and as a result, the printing durability is improved.

The concentration of the alkali metal silicate used in the silicate treatment is preferably 1 to 30% by weight, more preferably 2 to 15% by weight, and the pH at 25 ° C. is 10%.
~ 13, preferably at 50-90 ° C.
The immersion is performed for 5 to 60 seconds, more preferably 5 to 40 seconds.

As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used, and among them, sodium silicate and potassium silicate are preferable. PH of alkali metal silicate aqueous solution
Examples of the hydroxide used to increase the value include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like, and preferably, sodium hydroxide and potassium hydroxide are used.

Incidentally, an alkaline earth metal salt or a Group IVA metal salt may be added to the above treatment liquid. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfates, hydrochlorides, phosphates, acetates, oxalates, borates, and the like. Is mentioned. Group IVA metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide,
Examples thereof include zirconium chloride oxide, zirconium dioxide, zirconium oxychloride, and zirconium tetrachloride. The alkaline earth metal or Group IVA metal salt can be used alone or in combination of two or more.

The ink receiving layer of the present invention contains a lipophilic organic polymer soluble in a solvent capable of forming a film. Useful organic polymers include polyester, polyurethane, polyurea, polyimide, polysiloxane, polycarbonate, phenoxy resin, epoxy resin, phenol / formaldehyde resin, alkylphenol / formaldehyde resin, polyvinyl acetate, acrylic resin and copolymers thereof, and polyvinylphenol. , Polyvinyl halogenated phenol, methacrylic resin and its copolymer, acrylamide copolymer, methacrylamide copolymer, polyvinyl formal, polyamide, polyvinyl butyral, polystyrene, cellulose ester resin,
Examples thereof include polyvinyl chloride and polyvinylidene chloride.

Among these, as a more preferred compound, a resin having a hydroxyl group, a carboxyl group, a sulfonamide group or a trialkoxysilyl group in a side chain is excellent in adhesion to a substrate or an upper hydrophilic layer, and in some cases, It is desirable because it is easily cured with a crosslinking agent. In addition, an acrylonitrile copolymer, a polyurethane, a copolymer having a sulfonamide group in a side chain or a copolymer having a hydroxyl group in a side chain, which is photocured with a diazo resin, is preferable.

Other phenol, cresol (m-cresol, p-cresol, m / p mixed cresol), phenol / cresol (m-cresol, p-cresol, m / p mixed cresol), phenol-modified xylene, t-butylphenol, Octylphenol, resorcinol, pyrogallol, catechol, chlorophenol (m-Cl, p-Cl), bromophenol (m-
Novolak resins and resole resins for condensation with formaldehyde such as Br, p-Br), salicylic acid and phloroglucinol, as well as condensation resins for the above phenolic compounds and acetone are useful.

As other suitable high molecular compounds, there can be mentioned copolymers having a molecular weight of usually 10,000 to 200,000, which contains the following monomers (1) to (12) as constituent units. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, for example, N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacryl Amide, o
-, M- and p-hydroxystyrene, o-, m- and p-hydroxyphenyl acrylate or methacrylate, (2) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-
Hydroxyethyl acrylate or 2-hydroxyethyl methacrylate,

(3) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, acrylic acid-2 (Substituted) acrylates such as -chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, (4) methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate, (Substituted) methacrylates such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate;

(5) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide, N-hexyl acrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N
-Hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N
-Phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N
Acrylamide or methacrylamide such as -ethyl-N-phenylmethacrylamide,

(6) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether; (7) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate; (8) styrenes such as styrene, methyl styrene and chloromethyl styrene; 9)
Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (10) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene; (11) N
-Vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc.

(12) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N- [1- (3-aminosulfonyl) Naphthyl] acrylamide, acrylamides such as N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonyl) Methacrylamides such as phenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, and o-aminosulfonylphenyl acrylate, m-amino Sulfo sulfonyl phenyl acrylate,
p-aminosulfonylphenyl acrylate, 1- (3
-Aminosulfonylphenylnaphthyl) unsaturated sulfonamides such as acrylates such as acrylate, o-aminosulfonylphenylmethacrylate, m
Unsaturated sulfonamides such as methacrylic esters such as -aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate and 1- (3-aminosulfonylphenylnaphthyl) methacrylate;

The ink receiving layer of the present invention further comprises a crosslinking agent,
An adhesion aid, a colorant, inorganic or organic fine particles, a coating surface condition improving agent, and a plasticizer can be added as necessary. In addition, the ink receiving layer may contain a light-to-heat conversion agent for increasing the sensitivity or a heat coloring or decoloring additive for forming a printed image after exposure.

Specific crosslinking agents for crosslinking organic polymers include diazo resins, aromatic azide compounds, epoxy resins, isocyanate compounds, blocked isocyanate compounds, initial hydrolyzed condensates of tetraalkoxy silicon, glyoxal, aldehyde compounds and methylol. Compounds can be mentioned.

As the adhesion aid, the above diazo resin is excellent in adhesion to the substrate and the hydrophilic layer. In addition, a silane coupling agent, an isocyanate compound, and a titanium-based coupling agent are also useful.

As the coloring agent, ordinary dyes and pigments are used. In particular, rhodamine 6G chloride, rhodamine B chloride, crystal violet, malachite green oxalate, oxazine 4 perchlorate, quinizarin,
2- (α-naphthyl) -5-phenyloxazole and coumarin-4. Specifically, as other dyes,
Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black B
Y, oil black BS, oil black T-505
(The above are manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI4255)
5), methyl violet (CI42535), ethyl violet, methylene blue (CI52015), patent pure blue (manufactured by Sumitomo Sangoku Chemical Co., Ltd.), brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4
Triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes such as -p-diethylaminophenyliminaphthoquinone and cyano-p-diethylaminophenylacetanilide; -293247, Japanese Patent Application No. 7-3351.
No. 45 can be mentioned. When the dye is added to the ink receiving layer, it is usually about 0.02 to 10% by weight based on the total solid content of the receiving layer.
More preferably, the proportion is from about 0.1 to 5% by weight.

Further, fluorine-based surfactants and silicon-based surfactants, which are well-known compounds as coating surface condition improvers, can also be used. Specifically, a surfactant having a perfluoroalkyl group or a dimethylsiloxane group is useful for preparing the coated surface.

Examples of the inorganic or organic fine particles usable in the present invention include colloidal silica and colloidal aluminum having a diameter of 10 nm to 100 nm, and inactive particles having a particle size larger than those of the colloids, for example, silica particles, surface hydrophobization. Silica particles, alumina particles, titanium dioxide particles, other heavy metal particles, clay and talc. The addition of these inorganic or organic fine particles to the ink receiving layer has the effect of improving the adhesion to the upper hydrophilic layer and increasing the printing durability in printing. The addition ratio of these fine particles in the ink receiving layer is 80% by weight or less of the total amount, preferably 40% by weight or less.

Further, a plasticizer may be added to the ink receiving layer of the present invention, if necessary, in order to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers of acrylic acid or methacrylic acid And polymers.

Further, it is preferable to add a coloring or decoloring compound to the ink receiving layer of the present invention in order to sharpen the image area and the non-image area when exposed. For example,
Leuco dyes (leucomalachite green, leucomalachite green, etc.) along with thermal acid generators such as diazo compounds and diphenyliodonium salts
Leuco crystal violet, lactone of crystal violet, etc.) and PH discoloration dye (eg, dye such as ethyl violet, Victoria Poor Blue BOH)
Is used. In addition, a combination of an acid coloring dye and an acidic binder as described in EP 897134 is also effective. In this case, the bond in the associated state forming the dye is broken by heating, and a lactone is formed to change from colored to colorless. The addition ratio of these coloring or decoloring systems is 10% by weight based on the total solids in the receiving layer.
It is preferably at most 5% by weight.

As a solvent for coating the ink receiving layer, alcohols (methanol, ethanol, propyl alcohol, ethylene glycol, diethylene glycol,
Propylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc.), ethers (tetrahydrofuran, ethylene glycol dimethyl ether, propylene glycol dimethyl ether, tetrahydropyran, etc.), ketones (acetone, methyl ethyl ketone, Acetylacetone, etc.), esters (methyl acetate, ethylene glycol monomethyl monoacetate, methyl lactate, ethyl lactate,
Gamma-butyrolactone), amides (formamide, N-methylformamide, pyrrolidone, N-methylpyrrolidone, etc.) and the like can be used. These solvents are used alone or in a mixed state. When preparing a coating solution, the concentration of the components of the ink receiving layer (total solids including additives) in the solvent is preferably 1 to 50% by weight. In addition, a film can be formed not only from the above-mentioned application from an organic solvent but also from an aqueous emulsion. In this case, the concentration is preferably 5% by weight to 50% by weight.

The thickness of the ink receiving layer in the present invention after coating and drying is not particularly limited, but is preferably 0.1 μm or more because it functions as a heat insulating layer when provided on a metal plate. It is more preferably at least 0.2 μm. When a lipophilic plastic film is used as the substrate, the ink receiving layer only needs to be able to function as an adhesive layer with the upper layer. It is preferably at least 05 μm.

The hydrophilic layer used in the present invention is a layer which is insoluble in a fountain solution by lithographic printing using a fountain solution and ink, and is a layer of beryllium, magnesium, aluminum, silicon,
Titanium, boron, germanium, tin, zirconium,
It is formed by applying a solution containing colloidal particulate oxide or hydroxide of at least one element selected from iron, vanadium, antimony and transition metal, and polyacrylic acid. Aluminum, silicon, titanium and zirconium are particularly preferred among the elements constituting the colloidal particulate oxide or hydroxide used in the present invention.

The size of the colloid used in the present invention is as follows.
Spherical silica having a particle size of 5 to 100 nm is preferable. Spherical particles having a particle size of 10 to 50 nm are 50 to 400 nm
Can be used. Feathers such as 100 nm × 10 nm like aluminum oxide or hydroxide colloids are also effective.

These colloids can be prepared by various known methods such as hydrolysis of halides or alkoxy compounds of the above elements or condensation of hydroxides. For example,
A sol can also be prepared by applying a hydrolysis / condensation reaction directly from di, tri and / or tetraalkoxysilane under an acid catalyst to apply. When this sol is applied, a stronger hydrophilic three-dimensional crosslinked film can be obtained. In addition, a commercially available product such as Nissan Chemical Industries, Ltd. may be selected and used as the colloid dispersion liquid.

The hydrophilic layer of the present invention can contain a hydrophilic resin. As the hydrophilic resin, those having a hydrophilic group such as hydroxyl, carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl, carboxymethyl and the like are preferable.

Specific hydrophilic resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and their Na salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, Polyacrylic acids and their salts, polymethacrylic acids and their salts, vinyl alcohol / acrylic acid copolymers and their salts, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate Homopolymers and copolymers, hydroxypropyl acrylate homopolymers and copolymers, hydroxybutyl methacrylate homopolymers and copolymers, hydro Homopolymers and copolymers of sibutyl acrylate, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, and hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral having a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight; Examples thereof include polyvinylpyrrolidone, acrylamide homopolymers and copolymers, methacrylamide homopolymers and polymers, and N-methylolacrylamide homopolymers and copolymers.

These hydrophilic resins are used together with a colloid, and the ratio of addition thereof is as follows when the hydrophilic resin is water-soluble.
The total solid content of the hydrophilic layer is preferably 40% by weight or less, and in the case of a non-water-soluble hydrophilic resin, the total solid content is preferably 20% by weight or less.

The hydrophilic layer of the present invention may contain, in addition to the above-mentioned colloid and hydrophilic resin, a crosslinking agent which promotes the crosslinking of the colloid. As such a colloid crosslinking agent, an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide or aminopropyltrialkoxysilane is preferable. It is preferable that the addition ratio is 5% by weight or less of the total solid content of the hydrophilic layer.

Although the hydrophilic resin can be used as it is, it may be used together with a crosslinking agent for the hydrophilic resin other than the colloid as needed in order to enhance the printing durability. Examples of such a crosslinking agent include initial hydrolysis and condensate of formaldehyde, glyoxal, polyisocyanate and tetraalkoxysilane, dimethylol urea and hexamethylol melamine.

The hydrophilic layer containing each component described above is provided by preparing a solution in which each component is dissolved or dispersed in a solvent, and applying the solution. As the main solvent of the hydrophilic layer coating solution, water and low-boiling alcohols such as methanol, ethanol and propanol are used alone or as a mixture.

The hydrophilic layer of the present invention may further include a well-known fluorine-based surfactant for improving the surface state of the coating.
A silicon-based surfactant, a polyoxyethylene-based surfactant, or the like may be added.

The coating thickness of the hydrophilic layer of the present invention is preferably from 0.1 μm to 3 μm. Within this range, ablation is good and printing durability is good.

In the heat-sensitive lithographic printing plate of the present invention, a hydrophilic overcoat layer can be provided on the hydrophilic layer in order to suppress scattering of scum by ablation and to prevent contamination of the hydrophilic layer by a lipophilic substance.

The hydrophilic overcoat layer used in the present invention can be removed on a printing press, and is made of a resin selected from a water-soluble resin or a water-swellable resin obtained by partially crosslinking a water-soluble resin. contains.

Such a water-soluble resin is selected from a water-soluble natural polymer and a synthetic polymer, and is used together with a cross-linking agent.
Specific examples of the water-soluble resin preferably used in the present invention include, as natural polymers, gum arabic, water-soluble soybean polysaccharide, cellulose derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) Body, white dextrin, pullulan,
In synthetic polymers such as enzymatically degraded etherified dextrin,
Polyvinyl alcohol (Polyvinyl acetate hydrolysis rate 6)
5% or more), polyacrylic acid, its alkali metal salt or amine salt, polyacrylic acid copolymer, its alkali metal salt or amine salt, polymethacrylic acid, its alkali metal salt or amine salt, vinyl alcohol / acrylic Acid copolymer and its alkali metal salt or amine salt, polyacrylamide, its copolymer, polyhydroxyethyl acrylate, polyvinylpyrrolidone,
The copolymer, polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, alkali metal salt or amine salt thereof, poly-2-acrylamide- Examples thereof include 2-methyl-1-propanesulfonic acid copolymers, alkali metal salts and amine salts thereof. Further, according to the purpose, two or more of these resins can be used in combination. However, the invention is not limited to these examples.

When at least one or more of the water-soluble resins is partially crosslinked to form an overcoat layer on the hydrophilic layer, the crosslinking is carried out by a crosslinking reaction using a reactive functional group of the water-soluble resin. . The cross-linking reaction may be covalent cross-linking or ionic cross-linking.

The crosslinking reduces the tackiness of the surface of the overcoat layer and improves the handleability. However, if the crosslinking proceeds too much, the overcoat layer changes to lipophilic and it is difficult to remove the overcoat layer on a printing press. Therefore, appropriate partial cross-linking is preferable. The preferred degree of partial crosslinking is 2
When the printing plate is immersed in 5 ° C. water, it takes 30 seconds to 10 seconds.
In minutes, the hydrophilic overcoat layer remains without being eluted, but is eluted in 10 minutes or more.

Examples of the compound used in the crosslinking reaction include known polyfunctional compounds having a crosslinking property, such as polyepoxy compounds, polyisocyanate compounds, polyalkoxysilyl compounds, polyvalent metal salt compounds, polyamine compounds, and aldehyde compounds. And hydrazine. The crosslinking reaction can be accelerated by adding a known catalyst.

Specific examples of known polyfunctional compounds having a crosslinking property include the following compounds.

Specific examples of the polyepoxy compound include glycerin polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether,
And polycondensates of bisphenols or hydrogenated products thereof with epihalohydrin.

Specific examples of the polyamine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, propylenediamine, polyethyleneimine, and polyamidoamine.

Specific examples of the polyisocyanate compound include tolylene diisocyanate, diphenylmethane isocyanate, liquid diphenylmethane diisocyanate,
Aromatic isocyanates such as polymethylene polyphenyl isocyanate, xylylene diisocyanate, naphthalene-1,5-diisocyanate, cyclohexanephenylene diisocyanate, isopropylbenzene-2,4-diisocyanate; aliphatic isocyanates such as hexamethylene diisocyanate and decamethylene diisocyanate; Cyclohexyl diisocyanate, alicyclic diisocyanate such as isophorone diisocyanate,
Further, a polypropylene glycol / tolylene diisocyanate addition reaction product may, for example, be mentioned.

Examples of the silane compound include methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl)- γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,
β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, 3-chloropropylmethyldimethoxysilane, vinyltris (methylethylketoxime) silane, methyltris (methylethylketoxime) silane , Vinyltriacetoxysilane, etc.

Examples of the titanate compound include tetraethyl orthosilicate, bis (dioctyl pyrophosphate) ethylene titanate, isopropyl triactanoyl titanate, isopropyl dimethacryl isostearyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl (dioctyl phosphate) titanate) and isopropyl Tricumylphenyl titanate, isopropyl tri (N-aminoethylaminoethyl) titanate, dicumylphenyloxyacetate titanate, diisostearoylethylene titanate, isopropyltriinstearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl phosphate) titanate , Tetraiso Ropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditrisyl phosphite) titanate, tetra (2,2 diallyloxymethyl-1-butyl) bis (ditridecyl phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate Titanates, bis (dioctyl pyrophosphate) oxyacetate titanates, and the like.

Examples of the aldehyde compound include formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, glyoxal, glutaraldehyde, terephthalaldehyde and the like.

Examples of the polyvalent metal salt compound include water-soluble salts of metals such as zinc, calcium, magnesium, barium, strontium, cobalt, manganese and nickel.

These crosslinking agents can be used alone or in combination of two or more. Among these crosslinking agents, a particularly preferred crosslinking agent is a water-soluble crosslinking agent, but a water-insoluble one can be used by dispersing it in water with a dispersant.

Particularly preferred combinations of the water-soluble resin and the crosslinking agent include carboxylic acid-containing water-soluble resin / polyvalent metal compound, carboxylic acid-containing water-soluble resin / water-soluble epoxy resin, and hydroxyl group-containing resin / dialdehydes. .

The preferred amount of the crosslinking agent is 2 to 2 of the water-soluble resin.
-10% by weight. Within this range, good water resistance can be obtained without impairing the removability of the overcoat layer on a printing press.

In addition, a nonionic surfactant can be mainly added to the overcoat layer in the case of application of an aqueous solution for the purpose of ensuring uniformity of application. Specific examples of such a nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl ether, and the like. . The proportion of the nonionic surfactant in the total solid content of the overcoat layer is preferably 0.05 to 5% by weight, and more preferably 1 to 3% by weight.

When the water-soluble resin is not crosslinked, the thickness of the overcoat layer of the present invention is from 0.1 μm to 4.
0 μm is preferred, and a more preferred range is from 0.1 μm to 1.0 μm. When the water-soluble resin is partially crosslinked, the range is preferably 0.1 to 0.5 μm, and 0.1 to 0.3 μm.
μm is more preferred. Within this range, good scattering of ablation scum can be obtained without impairing the removability of the overcoat layer on the printing press.

In the present invention, a photothermal conversion agent having a function of absorbing infrared rays and generating heat is added to at least one of the ink receiving layer, the hydrophilic layer and the overcoat layer in order to increase the sensitivity to infrared rays. .

The photothermal conversion agent may be any substance that absorbs light of 700 nm or more, and various pigments and dyes can be used. Examples of pigments include commercially available pigment and color index (CI) handbook, “Latest Pigment Handbook” (edited by The Japan Pigment Technical Association, 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “printing”. Pigments described in "Ink Technology" (CMC Publishing, 1984) can be used.

Examples of the types of pigments include black pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and polymer-bound pigments. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelated azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments And quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like.

These pigments may be used without surface treatment, or may be used after surface treatment. The method of surface treatment is a method of surface coating a hydrophilic resin or lipophilic resin,
A method of attaching a surfactant, a method of bonding a reactive substance (for example, silica sol, alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound, and the like) to the surface of the pigment are considered. The above surface treatment method,
It is described in "Properties and Applications of Metallic Soaps" (Koshobo), "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986). Among these pigments, those that absorb infrared rays are preferred because they are suitable for use in lasers that emit infrared rays. As such a pigment that absorbs infrared rays, carbon black is particularly preferred.

As the pigment to be added to the hydrophilic layer and the overcoat layer of the present invention, particularly, the surface is coated with a hydrophilic resin or silica sol so as to easily disperse with a water-soluble or hydrophilic resin and not to impair the hydrophilicity. Carbon black is useful.

The particle size of the pigment is preferably in the range of 0.01 μm to 1 μm, and more preferably in the range of 0.01 μm to 0.5 μm. As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. As the disperser, an ultrasonic disperser,
Sand mills, attritors, pearl mills, super mills, ball mills, impellers, dispersers, KD mills, colloid mills, dynatrons, three-roll mills, pressure kneaders and the like can be mentioned. Details are described in “Latest Pigment Application Technology” (CMC Publishing, 1986).

As the dye, commercially available dyes and literatures (for example, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970,
"Chemical Industry", May 1986, p. 45-51 "Near-infrared absorbing dyes", "Development and market trends of functional dyes in the 1990s", Chapter 2, Section 2.3 (1990), or known dyes described in patents can be used. . Specifically, infrared absorbing dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, polymethine dyes, and cyanine dyes are preferred.

Further, examples of the infrared absorbing dye include, for example, JP-A-58-125246 and JP-A-59-84356.
Cyanine dyes described in JP-A-60-78787, JP-A-58-173696, JP-A-58-173696
181690, methine dyes described in JP-A-58-194595 and the like, JP-A-58-112793,
JP-A-58-224793, JP-A-59-48187
JP-A-59-73996, JP-A-60-5294
No. 0, naphthoquinone dyes described in JP-A-60-63744 and the like, squalilium dyes described in JP-A-58-112792 and the like, British Patent 434,8
No. 75, and US Pat. No. 4,756,9.
No. 93, a cyanine dye described in U.S. Pat. No. 4,973,572, a dye described in JP-A-10-268512, and a phthalocyanine compound described in JP-A-11-235883.

As a dye, US Pat. No. 5,156,
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (US Pat. No. 4,327,169)
Described in JP-A-58-18.
No. 1051, No. 58-220143, No. 59-413
No. 63, No. 59-84248, No. 59-84249
Pyrylium compounds described in JP-A-59-146063 and JP-A-59-146061;
Cyanine dyes described in U.S. Pat. No. 2,216,146, pentamethine thiopyrylium salts described in U.S. Pat. No. 4,283,475, and Japanese Patent Publication Nos. 5-135514 and 5-19702.
Nos. 4,059,098, 4,098,098, 4,098,097, and 3,087,098. Also preferred are pyrylium compounds described in Japanese Patent Application Publication No. JP-A-2002-209, Epolite III-178, Epolite III-130, Epolite III-125 and the like. Among these, a particularly preferred dye to be added to the overcoat layer and the hydrophilic layer is a water-soluble dye, and specific examples are listed below by structural formulas.

[0080]

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[0081]

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The dye used in the ink receiving layer of the present invention may be the above-mentioned infrared absorbing dye, but is preferably a more lipophilic dye. More preferred dyes include the dyes exemplified below.

[0083]

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[0084]

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The addition ratio of the photothermal conversion agent is 1 to 50% by weight, preferably 2 to 20% by weight of the solid content in the hydrophilic layer. In the overcoat layer, 1 to 70% by weight of solids,
Preferably 2 to 50% by weight, when the photothermal conversion agent is a dye,
The proportion is particularly preferably 2 to 30% by weight, and when the photothermal conversion agent is a pigment, the proportion is particularly preferably 20 to 50% by weight. The addition ratio of the photothermal conversion agent to the ink receiving layer is preferably 20% by weight or less of the total solids of the ink receiving layer, and particularly preferably 15% by weight or less. Within these ranges, good sensitivity can be obtained without impairing the film strength of each layer.

The heat-sensitive lithographic printing plate of the present invention forms an image by heat. Specifically, direct image-like recording using a thermal recording head or the like, scanning exposure using an infrared laser, high-intensity flash exposure such as a xenon discharge lamp, or infrared lamp exposure is used. Semiconductors that emit infrared light having a wavelength of 700 to 1200 nm are used. Exposure with a solid-state high-output infrared laser such as a laser or a YAG laser is preferable.

The image-exposed printing plate of the present invention can be mounted on a printing press without any further processing. Alternatively, it is also possible to attach a printing original plate to a printing press, perform laser exposure on the printing press, and then perform printing as it is. When printing is started using the ink and the fountain solution, the overcoat layer and the hydrophilic layer of the exposed area are removed by dissolution with the fountain solution, or transfer to a blanket, and further transfer to paper,
The ink is deposited on the exposed ink receiving layer, and a printed matter is obtained.

[0088]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 [Production Example of Aluminum Support] Aluminum 99.5
0.01% by weight of copper and 0.03% by weight of titanium
%, 0.3% by weight of iron and 0.1% by weight of silicon
0.24mm thickness of JISA1050 aluminum material
The rolled plate is made of 400 mesh pamistone (manufactured by Kyoritsu Ceramics).
Using a 20% by weight aqueous suspension and a rotating nylon brush
After graining the surface, it was thoroughly washed with water. this
15% by weight aqueous sodium hydroxide solution (aluminum 4.
5% by weight) to dissolve 5 g of aluminum
/ M^TwoAnd then rinse with running water
Was. Furthermore, neutralize with 1% by weight nitric acid aqueous solution, then 0.7 weight
In aqueous nitric acid solution (containing 0.5% by weight of aluminum)
A rectangle with a voltage of 10.5 V at the time of anode and a voltage of 9.3 V at the time of cathode
Wave alternating voltage (current ratio r = 0.90, Japanese Patent Publication No. 58-5)
796, the current waveform described in the embodiment).
160C / dm^TwoElectrolytic surface roughening treatment with the amount of electricity at the anode
went. After washing with water, 10% by weight of sodium hydroxide at 35 ° C
Immersion in aqueous solution, aluminum dissolution amount 1g / m ^Two
And then washed with water. Next, 50
Immersion in 30% by weight sulfuric acid aqueous solution
After that, it was washed with water. Further, a 20% by weight aqueous solution of sulfuric acid at 35 ° C.
DC current in liquid (containing 0.8% aluminum)
Then, a porous anodic oxide film forming treatment was performed. Sand
And a current density of 13 A / dm^TwoAnd electrolysis time
By adjustment, anodic oxide film weight 2.7 g / m^TwoSupport
Was prepared. After washing this support with water, sodium silicate at 70 ° C
Immersion treatment in 2.0% by weight aqueous solution of lithium for 30 seconds and washing with water
Dried. 15mg / m as silicon^TwoSo
Was. The support obtained as described above is a Macbeth RD
The reflection density measured with a 920 reflection densitometer is 0.30,
The core wire average roughness Ra was 0.58 μm.

[Coating of ink receiving layer]
An ink receiving layer coating solution having the following composition was applied to a coating solution amount of 11.2.
Coating was performed with a bar coater so as to be 5 ml / m ² . Then, it is dried by heating at 100 ° C. for 1 minute, and the dried coating amount is about 0.1%.
An ink receiving layer of 45 g / m ² was obtained.

(Coating solution of ink receiving layer) Epicoat 1100L (manufactured by Yuka Shell Epoxy) 0.8 g Epicoat 1001 (manufactured by Yuka Shell Epoxy) 0.2 g Photothermal conversion agent (IR described in this specification) -24) 0.2 g Methyl ethyl ketone 13 g Propylene glycol monomethyl ether 12 g

[Coating of Hydrophilic Layer] On the ink receiving layer thus provided, the following hydrophilic layer coating solution (I) was coated with a bar, dried at 100 ° C. for 1 minute, and dried to a dry coating amount of 0.1 μm. 39
g / m ² of the hydrophilic layer was obtained.

(Hydrophilic Layer Coating Solution (I)) Methanol silica (manufactured by Nissan Chemical Industries, Ltd .: colloid composed of a methanol solution containing 30% by weight of silica having a particle size of 10 to 20 nm) 3 g Polyacrylic acid (weight average molecular weight: 2. 50,000) 5% by weight methanol solution 2 g Methyl lactate 1 g Methanol 17.53 g

[Application of Overcoat Layer] An overcoat layer coating solution having the following composition was bar-coated on the hydrophilic layer.
Dry at 100 ° C for 90 seconds, dry application weight 0.22g
A heat-sensitive lithographic printing plate having an overcoat layer of / m ² was prepared.

(Coating solution for overcoat layer) Aqueous solution containing 28% by weight of gum arabic 1.5g Photothermal conversion agent (Dye IR-10 described in this specification) 0.042g Polyoxyethylene nonylphenyl ether (10% by weight aqueous solution) ) 0.168g ion exchange water 22g

The above heat-sensitive lithographic printing plate was treated for 200 m with a Trendsetter (a plate setter equipped with a 40 W 830 nm semiconductor laser) manufactured by Creo Corporation.
Exposure was performed with an energy of J / cm ² . The exposed original plate was attached to Komori Corporation's Lithrone printing machine without further processing, and the plate etch solution EU was used.
-3 (manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol (volume ratio 1/99/10) and dampening using Geos G black ink manufactured by Dainippon Ink and Chemicals, Inc. When water and ink were operated at the same time and art-coated paper was supplied and printing was started, the ink was completely deposited on the fifth printout, and 30,000 good prints without stains were obtained thereafter. .

Comparative Example 1 A heat-sensitive lithographic printing plate for comparison was prepared in exactly the same manner as in the production example of the aluminum support of Example 1 except that the concentration of the aqueous solution of sodium silicate was changed to 0.2% by weight. Produced. The amount of silicate attached was 5 mg / m ² as silicon.
Met. Next, this heat-sensitive lithographic printing plate was exposed and printed in the same manner as in Example 1.
Although it was within the number of sheets, the printing durability was 20,000 sheets.

Example 2 The following hydrophilic layer coating liquid (II) was coated on the ink receiving layer of Example 1 with a bar, dried at 100 ° C. for 1 minute, and dried at a coating weight of 0.39 g / m ² . A heat-sensitive lithographic printing plate having a hydrophilic layer and no overcoat layer was obtained.

(Hydrophilic Layer Coating Solution (II)) Methanol silica (same as in Example 1) 3 g Methanol solution containing 5% by weight of polyacrylic acid (weight average molecular weight: 25,000) 2 g Photothermal conversion agent (this specification) IR-10) 0.1 g Methyl lactate 1 g Methanol 17.53 g

This heat-sensitive lithographic printing original plate was exposed using the same plate setter as in Example 1 and printed under the same printing conditions. As a result, the number of printed sheets was 5, and the number of printings was 30,000. On the other hand, in a comparative printing original plate obtained in the same manner as in Example 2 except that a support having a silicate adhesion amount of 5 mg / m ² as silicon was used, the number of printings was 2
It was 10,000 copies.

Example 3 On the hydrophilic layer of Example 1, an overcoat layer coating solution OC-2 having the following composition was coated with a bar and dried at 100 ° C. for 90 seconds to obtain a dry coating weight of 0.22 g / m ² . A heat-sensitive planographic printing plate having an overcoat layer was prepared.

(Overcoat Layer Coating Solution OC-2) Gum Arabic (28% by weight aqueous solution) 1.5 g Light-to-heat converting agent (Dye IR-10 described in this specification) 0.042 g Polyoxyethylene nonylphenyl ether (10 Wt% aqueous solution) 0.168 g Calcium acetate (10 wt% aqueous solution) 0.3 g Deionized water 22 g

This heat-sensitive lithographic printing original plate was exposed using the same plate setter as in Example 1, and printed under the same printing conditions. As a result, the number of printed sheets was 5, and the number of printings was 30,000. On the other hand, in the comparative printing original plate obtained in the same manner as in Example 3 except that a support having a silicate adhesion amount of 5 mg / m ² as silicon was used,
It was 10,000 copies.

[0104]

According to the present invention, it is possible to print by directly mounting on a printing machine without performing post-exposure processing.
An object of the present invention is to provide a heat-sensitive lithographic printing plate having further improved printing durability.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/11 G03F 7/11 7/36 7/36 F term (Reference) 2H025 AA12 AB03 AC08 AD01 AD03 CC20 DA02 DA18 DA20 DA36 DA40 FA03 FA10 FA19 2H096 AA07 AA08 BA16 CA03 CA05 CA20 EA04 GA45 LA16 2H114 AA04 AA22 AA24 AA27 BA01 DA04 DA15 DA25 DA26 DA46 DA52 DA55 DA73 EA01 EA03 FA16 GA03 GA05 GA06 GA08 GA09 GA34 GA38

Claims (2)

[Claims] 1. On an aluminum support, (1) an ink receiving layer and (2) a beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal. Heat-sensitive lithographic printing original plate having a hydrophilic layer containing at least one elemental colloidal particulate oxide or hydroxide, wherein at least one of the ink-receiving layer and the hydrophilic layer contains a photothermal conversion agent A heat-sensitive lithographic printing plate precursor, wherein the aluminum support has an anodic oxide film of ² g / m ² or more and a silicate film of 15 mg / m ² or more in silicon adhesion amount. 2. An ink comprising, on an aluminum support, (1) an ink receiving layer, (2) a hydrophilic layer according to claim 1, and (3) a hydrophilic overcoat layer removable on a printing press. At least one of the receiving layer, the hydrophilic layer and the hydrophilic overcoat layer is a heat-sensitive lithographic printing plate containing a light-to-heat conversion agent, and the aluminum support has an anodized film of ² g / m ² or more. , And the amount of silicon attached is 15 mg
A heat-sensitive lithographic printing plate having a silicate coating of at least / m ² .