JP2001293970A - Original plate for heat sensitive lithographic printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for heat sensitive lithographic printing, which is capable of printing directly through a printer without processing after exposure and provided with the substrate of an aluminum film improved in a sensitivity. SOLUTION: The original plate for heat sensitive lithographic printing is provided on the aluminum substrate with an ink receptor layer as well as a hydrophilic layer containing a colloidal granular oxide or the hydrogenate of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal while at least one layer of the ink receptor layer and the hydrophilic layer contains a light/heat converting agent. In this case, the aluminum substrate is characterized by having an anodized film of 2 g/m2 or more and receiving the application of bore widening treatment as well as the sealing treatment of more than 50% of sealing rate.

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, image recording by infrared laser beam scanning exposure based on digital signals is possible, and the recorded image can be mounted on a printing machine and printed without going through the conventional development process The present invention relates to a lithographic printing plate having improved sensitivity.

[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] For example, WO98 / 40212 discloses an ink receiving layer containing a photothermal converting agent for converting light into heat on a substrate, and a colloidal particulate oxide or hydroxide such as silicon on the ink receiving layer. A heat-sensitive lithographic printing plate having a hydrophilic layer is disclosed.

[0004] WO 99/19143 discloses that a photothermal conversion agent is added not only to the ink receiving layer but also to the hydrophilic layer. WO 99/19144 discloses that a heat insulating layer made of a thermoplastic polymer or the like is provided between a support and a hydrophilic layer. The purpose of these publications is, in the case of WO 98/40212,
Since the light-to-heat conversion agent is contained in the layer adjacent to the substrate, the generated heat diffuses to the substrate and reduces the proportion of heat used for ablation, resulting in lower sensitivity of the heat-sensitive lithographic printing plate. It was an improvement.

[0005]

However, according to the technique disclosed in the above publication, even when a material having a high thermal conductivity such as an aluminum plate is used as a support, the effect of diffusion of heat to the support is large, and a heat-sensitive lithographic plate is used. The sensitivity of the printing plate was still insufficient.

Accordingly, an object of the present invention is to solve the above-mentioned problems. That is, an object of the present invention is to provide a heat-sensitive lithographic printing plate precursor having an aluminum plate as a support, which can be directly mounted on a printing machine and printed without any processing after exposure, and has improved sensitivity. Is to provide.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that when an aluminum plate is used as a support, the micropores of the anodic oxide film are dissolved and enlarged, and furthermore, a sealing treatment is carried out. The inventors have found that sensitivity can be obtained, and have reached the present invention. That is, the present invention is as follows.

[0008] 1. On an aluminum support, a) an ink-receiving layer, and b) at least one element 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, wherein at least one of the ink-receiving layer and the hydrophilic layer contains a light-to-heat conversion agent; A heat-sensitive lithographic printing plate, wherein the body has an anodic oxide film of ² g / m ² or more, and has been subjected to a pore widening treatment and a sealing treatment with a sealing ratio of 50% or more.

[0009] 2. A) an ink-receiving layer, b) the hydrophilic layer according to claim 1 and c) a water-soluble overcoat layer on an aluminum support, wherein at least one of the ink-receiving layer, the hydrophilic layer and the water-soluble overcoat layer is provided. One layer is a heat-sensitive lithographic printing plate containing a photothermal conversion agent,
A heat-sensitive lithographic printing plate, wherein the aluminum support has an anodic oxide film of ² g / m ² or more, and has been subjected to pore widening treatment and sealing treatment with a sealing ratio of 50% or more. .

[0010]

Embodiments of the present invention will be described below in detail. The aluminum support used in the present invention is an aluminum plate having an anodized film of 2.0 g / m ² or more, and having been subjected to a pore widening treatment and a sealing treatment with a sealing ratio of 50% or more. As the raw aluminum plate used for the aluminum support of the present invention, an aluminum plate of a conventionally known and used material can be appropriately used. That is, the raw aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a different element. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is 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.

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

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. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. 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. As an electrochemical surface roughening method, there is a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Also, Japanese Patent Application Laid-Open No. 54-6390
An electrolytic surface roughening method using a mixed acid as described in No. 2 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 that form 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 preferably 2.0 g / m ² or more, more preferably 2.0 to 6.0 g / m ² , and particularly preferably 2.0 to 6.0 g / m ^2.
It is 5.0 g / m ² . If it is less than 2.0 g / m ² , the effect of increasing sensitivity when pore widening treatment is performed and sealing is insufficient.

In the present invention, after the distribution density of the micropores is adjusted by optimizing the anodic oxidation conditions, treatment with an acid or alkali aqueous solution (pore widening treatment) for the purpose of expanding the size of the micropores is considered. Features. In this treatment, the aluminum substrate on which the anodic oxide film is formed is immersed in an aqueous acid or alkali solution, and the anodic oxide film is preferably treated at 0.05 to 20 g / m 2.
² , more preferably 0.1 to 5 g / m ² , particularly preferably 0.2 to 4 g / m ² .

The following conditions are desirable as processing conditions for obtaining the above-mentioned film dissolving amount. As a specific condition range, when treating with an aqueous acid solution, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid or phosphoric acid or a mixture thereof, and the concentration is preferably 10 to 500 g /
l, more preferably 20 to 100 g / l, and the temperature is preferably 10 to 90 ° C, more preferably 40 to 7 ° C.
0 ° C., the immersion time is preferably 10 to 300
Seconds, more preferably 30 to 120 seconds. On the other hand, when treating with an alkaline aqueous solution, it is preferable to use an aqueous solution of sodium hydroxide, potassium hydroxide, lithium hydroxide, or a mixture thereof, and the pH of the aqueous solution is preferably 9 to 13, more preferably 11.5
To 12.5, and the temperature is preferably 10 to 9
0 ° C, more preferably 30 to 50 ° C, and the immersion time is preferably 1 to 300 seconds, more preferably 5 to 3 seconds.
0 seconds. Within this range, good pore widening can be achieved without significantly shortening the time required to dissolve and reducing the working efficiency, or dissolving in an extremely short time and preventing practical control. Can be processed.

The aluminum substrate having the anodic oxide film of the present invention is subjected to a pore sealing treatment after the pore widening treatment. The sealing rate is preferably 50% or more, more preferably 90% or more. Here, the sealing rate (%) is defined by the following equation. Sealing rate = 100 × (surface area of unsealed area−surface area after sealed area)
÷ (Surface Area of Unsealed Hole) The above surface area is a value measured using QUANTASORB (Cantasorb, manufactured by Yuasa Ionics Co., Ltd.) which is a simple BET method.

As the sealing treatment to be applied, hot water treatment,
It can be carried out using a known method such as boiling water treatment, steam treatment, dichromate treatment, nitrite treatment, ammonium acetate treatment, and electrodeposition sealing treatment. As the hot water treatment, steam treatment, or boiling water treatment method, there are many known examples such as JP-A Nos. 4-176690 and 5-131773. The processing temperature is about 95 to 200 ° C., preferably about 100 to 150 ° C.
About 5 to 150 seconds at 00 ° C, 1 to 30 at 150 ° C
About a second is preferable.

As another sealing treatment, JP-B-36-220
No. 63 or the like can be used. Alternatively, JP-A-9-244
No. 227, a method of treating with an aqueous solution containing a phosphate and an inorganic fluorine compound can be used. Further, the method of treating with an aqueous solution containing a saccharide described in JP-A-9-134002 can also be used.
In addition, Japanese Patent Application Nos. 10-252078 and 10-
The method of treating with an aqueous solution containing titanium and fluorine described in No. 253411 can be used. Further, a treatment using an alkali metal silicate may be performed. In that case, a method described in US Pat. No. 3,181,461 can be used.

In the alkali metal silicate treatment, an alkali metal silicate aqueous solution having a pH of 10 to 13 at 25 ° C. which does not cause gelation of the solution and dissolution of the anodic oxide film is used. The sealing process can be performed by appropriately selecting processing conditions such as concentration, processing temperature, and processing time. Suitable alkali metal silicates include sodium silicate, potassium silicate, lithium silicate and the like. In order to adjust the pH of the alkali metal silicate aqueous solution to a high value, sodium hydroxide, potassium hydroxide, lithium hydroxide, or the like can be added.

If necessary, an alkaline earth metal salt or a Group IVB metal salt may be added to the aqueous alkali metal silicate solution. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and sulfates, hydrochlorides, phosphates, acetates, oxalates, and borates of these alkaline earth metals. And water-soluble salts such as salts. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, and the like. be able to. Alkaline earth metal salt or No.
Group IVB metal salts can be used alone or in combination of two or more. The preferred use amount range of these metal salts is 0.01 to 10% by weight, and the more preferred range is 0.05 to 5.0% by weight.

The ink receiving layer used in the present invention contains an organic polymer. The organic polymer is soluble in a solvent and can form a lipophilic film. Moreover,
It is desirable that the solvent is insoluble in the coating solvent of the upper hydrophilic layer. However, in some cases, a material which swells in the upper layer coating solvent has excellent adhesiveness to the hydrophilic layer, and may be desirable.
In addition, when an organic polymer that is soluble in the coating solvent for the hydrophilic layer is used, it is desirable to cure the ink receiving layer by devising, for example, adding a crosslinking agent.

Examples of useful organic polymers include polyesters, polyurethanes, polyureas, polyimides, polysiloxanes, polycarbonates, phenoxy resins, epoxy resins, novolak resins, resole resins, condensation resins of phenol compounds and acetone, polyvinyl acetate, and acrylic resins. And its copolymer, polyvinylphenol,
Polyvinylhalogenated phenol, methacrylic resin and its copolymer, acrylamide copolymer, methacrylamide copolymer, polyvinylformal, polyamide,
Examples thereof include polyvinyl butyral, polystyrene, cellulose ester resin, polyvinyl chloride and polyvinylidene chloride. Among these, as a more preferable 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, a crosslinking agent. It is desirable because it cures easily. In addition, an acrylonitrile copolymer, 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.

The novolak resin and the resol resin include 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-Br, p-B
r), addition condensation products of salicylic acid, phloroglucinol and the like with aldehydes such as formaldehyde and paraformaldehyde.

As other suitable high molecular compounds, there can be mentioned copolymers having the average molecular weight of usually from 100,000 to 200,000, using the monomers shown in the following (1) to (12) as constituent units. (1) acrylamides having an aromatic hydroxy group,
Methacrylamides, acrylates, methacrylates and hydroxystyrenes such as N
-(4-hydroxyphenyl) acrylamide or N
-(4-hydroxyphenyl) methacrylamide, o
-, M- and p-hydroxystyrene, o-, m- and p-hydroxyphenyl acrylate or methacrylate, (2) acrylates and methacrylates having an aliphatic hydroxy 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 Acrylates such as benzyl acrylate, 2-chloroethyl acrylate, 4-hydroxybutyl acrylate, glycidyl acrylate, N, N-dimethylaminoethyl acrylate,

(4) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, methacrylic acid
Methacrylic acid esters such as 2-chloroethyl, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N, N-dimethylaminoethyl methacrylate;
(5) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N-hexylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide,
N-cyclohexylmethacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenyl Methacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-
Acrylamide or methacrylamide such as 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; 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) Acrylamide or methacrylamides containing a sulfonamide group such as phenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide;
Further, o-aminosulfonylphenyl acrylate, m
-Aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, 1- (3-aminosulfonylphenylnaphthyl) acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, 1- (3 -Sulfonamide group-containing acrylates or methacrylates such as -aminosulfonylphenylnaphthyl) methacrylate.

These organic polymers can be dissolved in an appropriate solvent, applied to a substrate and dried to form an ink receiving layer on the substrate. Although it is possible to use only an organic polymer dissolved in a solvent, a crosslinking agent, an adhesion aid, a coloring agent, inorganic or organic fine particles, a coating surface condition improving agent, and a plasticizer can be added as necessary. . In addition, a heat coloring or decoloring additive for forming a printout image after exposure may be added.

As a crosslinking agent for crosslinking an organic polymer,
For example, a diazo resin, an aromatic azide compound, an epoxy resin, an isocyanate compound, a blocked isocyanate compound, an initial hydrolysis condensate of tetraalkoxy silicon, glyoxal, an aldehyde compound and a methylol compound can be exemplified.

As the adhesion aid, the above diazo resin is excellent in adhesion to a substrate and a hydrophilic layer. In addition, a silane coupling agent, an isocyanate compound and a titanium 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, quinizarin, 2- (α-naphthyl) -5- Phenyloxazole and the like. Specific examples of other dyes include Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green B
G, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Industries, Ltd.), Victoria Pure Blue, Crystal Violet (CI
42555), methyl violet (CI4253)
5), ethyl violet, methylene blue (CI52
015), Patent Pure Blue (manufactured by Sumitomo Sangoku Chemical), brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4-p-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide, etc. Triphenylmethane series represented by
Diphenylmethane, oxazine, xanthene, iminonaphthoquinone, azomethine or anthraquinone dyes or JP-A-62-293247,
Dyes described in JP-A-9-179290 can be exemplified. When the above dye is added to the ink receiving layer, it is usually used in an amount of about 0.0
The proportion is 2 to 10% by weight, more preferably 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.

The inorganic or organic fine powder which can be used in the present invention includes colloidal silica and colloidal aluminum having a diameter of from 10 to 100 nm, and inert particles having a particle size larger than these colloids, for example, silica particles and surface particles. Hydrophobized silica particles, alumina particles, titanium dioxide particles, other heavy metal particles, clay, talc and the like can be mentioned. The addition of these inorganic or organic fine powders 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 proportion of these fine powders added to the ink receiving layer is preferably not more than 80% by weight, more preferably not more than 40% by weight of the solid content of the ink receiving layer.

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 a polymer.

Further, the color-forming or decoloring-type additives which can be added to the ink receiving layer of the present invention include, for example, thermal acid generators such as diazo compounds and diphenyliodonium salts and leuco dyes (leucomalachite green, leuco crystal). Violet, a lactone of crystal violet, etc.) and a PH discoloration dye (for example, a dye such as ethyl violet or Victoria Pure Blue BOH) are used in combination. 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 proportion of these additives is preferably 10% by weight or less, more preferably 5% by weight or less, based on the solid content of the ink receiving layer.

As the 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, ethyl acetate, ethylene glycol monomethyl ether monoacetate, gamma-butyrolactone, methyl lactate, ethyl lactate, and the like, amides (formamide, N-methylformamide, pyrrolidone, N-methylpyrrolidone, and the like) can be used. These solvents are used alone or as a mixture. The concentration of the ink receiving layer component (total solid content including additives) in the coating liquid 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 of the present invention after coating and drying is 0.1 μm or more, and preferably 0.5 μm or more when added as a heat insulating layer. If the ink receiving layer is too thin, the heat generated will diffuse toward the aluminum substrate, resulting in reduced sensitivity. On the other hand, if it is too thin, the abrasion resistance is reduced, and the printing durability cannot be secured.

The hydrophilic layer of the present invention comprises a colloidal particulate oxide of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. Or contains a hydroxide.

The colloidal particulate oxides or hydroxides of these elements can be dispersed in a colloidal dispersion by various known methods such as hydrolysis of halides or alkoxy compounds of the above elements or condensation of hydroxides. Ie, made as colloidal particles. When it is added to a hydrophilic layer coating solution for forming a hydrophilic layer, it can be added in the form of a colloidal dispersion.

Among the oxides or hydroxides of these elements, particularly preferred are oxides or hydroxides of at least one element selected from aluminum, silicon, titanium and zirconium.

The colloidal particles of oxides or hydroxides of these elements have a colloidal particle size of 5% in the case of silica.
Spherical ones of 〜100 nm are preferred. 10-50n
Colloidal particles in the form of pearl necklaces in which m spherical particles are connected in a length of 50 to 400 nm can also be used. Feathers such as 100 nm × 10 nm, such as colloidal particles of aluminum oxide or hydroxide, are also effective. These colloidal dispersions can be purchased from commercial products such as Nissan Chemical Industries, Ltd.

As a dispersion medium of these colloidal particles,
In addition to water, organic solvents such as methanol, ethanol, ethylene glycol monomethyl ether, and methyl ethyl ketone are also useful.

In the hydrophilic layer of the present invention, a hydrophilic resin can be used together with the above colloid particles. By using a hydrophilic resin, the film properties of the hydrophilic layer can be enhanced, and the printing durability can be improved. Examples of the hydrophilic resin include hydroxyl,
Those having a hydrophilic group such as carboxyl, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl are preferred. Specific hydrophilic resins include gum arabic, casein, gelatin, starch derivatives, carboxymethyl cellulose and their sodium salts, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymer, styrene-maleic acid copolymer, polyacrylic acid and , Polymethacrylic acid and salts thereof, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, hydroxybutyl methacrylate And copolymers of hydroxybutyl acrylate Chromatography, polyethylene glycol, polypropylene oxide, polyvinyl alcohol, and hydrolysis degree of at least 60 wt%, preferably at least 8
0% by weight of hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, homopolymers and copolymers of acrylamide, homopolymers and polymers of methacrylamide,
Examples thereof include homopolymers and copolymers of N-methylolacrylamide.

Particularly preferred hydrophilic resins are non-water-soluble polymers containing hydroxyl groups, specifically, homopolymers and copolymers of hydroxyethyl methacrylate and copolymers of hydroxyethyl acrylate.

The proportion of these hydrophilic resins is preferably 40% by weight or less based on the solid content of the hydrophilic layer when the hydrophilic resin is water-soluble, and 2% by weight or less when the hydrophilic resin is not water-soluble.
It is preferably 0% by weight or less.

For the hydrophilic layer of the present invention, a resin having an aromatic hydroxyl group can be used. By using a resin having an aromatic hydroxyl group, it is possible to improve the coatability of the hydrophilic layer and, at the same time, improve the inking property of printing. As the resin having an aromatic hydroxyl group, methanol is added at 25 ° C for 5 hours.
It is preferable that the resin dissolves in an amount of at least% by weight, and examples thereof include alkali-soluble resins such as novolak resins, resole resins, polyvinylphenol resins, and ketone pyrogallol resins.

Preferred novolak resins include at least one hydroxyl-containing aromatic compound selected from phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol and resorcinol. And a novolak resin which is addition-condensed with at least one selected from aldehydes such as formaldehyde, acetaldehyde and propionaldehyde in the presence of an acidic catalyst. Instead of formaldehyde and acetaldehyde, paraformaldehyde and paraaldehyde, respectively, may be used. Among them, the mixing ratio of m-cresol: p-cresol: 2,5-xylenol: 3,5-xylenol: resorcinol is 40 to 100: 0 to 50: 0 to 20: 0 to 2 in a molar ratio.
A mixture of 0: 0 to 20 or a mixing ratio of phenol: m-cresol: p-cresol is 1 to 10 in molar ratio.
A novolak resin which is an addition condensation product of a mixture of 0: 0 to 70: 0 to 60 and an aldehyde is preferred. Of the aldehydes, formaldehyde is particularly preferred. The polystyrene-equivalent weight average molecular weight (hereinafter abbreviated as weight average molecular weight) of the novolak resin measured by gel permeation chromatography (hereinafter abbreviated as GPC) is preferably 1,000.
~ 15,000, more preferably from 1,500 to 10,
000 are used.

Preferred resole resins include phenol, m-cresol, o-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol, resorcinol, pyrogallol, bis- (4-hydroxyphenyl) methane, bisphenol -A, o-ethylphenol, m-ethylphenol, p-ethylphenol, propylphenol, n-butylphenol, t-
Hydroxy group-containing aromatic hydrocarbons such as butylphenol, 1-naphthol, and 2-naphthol, and at least one other polynuclear aromatic hydrocarbon having two or more hydroxyl groups are subjected to formaldehyde, acetaldehyde, propionaldehyde under an alkaline catalyst. And aldehydes such as benzaldehyde and furfural, and addition-condensation with at least one aldehyde or ketone selected from ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone. Instead of formaldehyde and acetaldehyde, paraformaldehyde and paraaldehyde, respectively, may be used. The weight average molecular weight of the resole resin is preferably 500 to 1
It is particularly preferably from 1,000 to 5,000.

Preferred polyvinyl phenol resins include o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene and 2- (m-hydroxyphenyl)
Examples thereof include homopolymers of hydroxystyrenes such as propylene and 2- (p-hydroxyphenyl) propylene, or copolymers of two or more thereof. Hydroxystyrenes may have a substituent such as chlorine such as chlorine, bromine, iodine and fluorine or an alkyl group having 1 to 4 carbon atoms on an aromatic ring. And a polyvinyl phenol which may have a halogen or an alkyl group having 1 to 4 carbon atoms. In addition, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl)
Those obtained by copolymerizing hydroxystyrenes such as propylene and 2- (p-hydroxyphenyl) propylene with methacrylic acid, acrylic acid, alkyl methacrylate or alkyl acrylate are also useful. The polyvinylphenol resin is usually obtained by polymerizing hydroxystyrene which may have a substituent, alone or in combination of two or more in the presence of a radical polymerization initiator or a cationic polymerization initiator. Such a polyvinyl phenol resin may be partially hydrogenated. Further, a resin in which some hydroxyl groups of the polyvinyl phenol resin are protected by a t-butoxycarbonyl group, a pyranyl group, a furanyl group, or the like may be used. The weight average molecular weight of the polyvinyl phenol resin is preferably 1,000 to 100,000.
0, particularly preferably 1,500 to 50,000.
As the ketone pyrogallol resin, an acetone pyrogallol resin is particularly useful.

The proportion of the resin having an aromatic hydroxyl group is from 1 to 20% by weight, preferably from 3 to 12% by weight, based on the solid content of the hydrophilic layer.

In the hydrophilic layer of the present invention, in addition to the colloidal oxide or hydroxide of the above-mentioned element and a resin having an aromatic hydroxyl group, a crosslinking agent for accelerating the crosslinking of the colloidal oxide or hydroxide is used. It may be added. As such a crosslinking agent, an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide, or aminopropyltrialkoxysilane is preferable. The addition ratio is
It is preferably 5% by weight or less of the solid content of the hydrophilic layer.

Further, to the hydrophilic layer of the present invention, a crosslinking agent for the above-mentioned hydrophilic resin or resin having an aromatic hydroxyl group may be added for the purpose of increasing the printing durability during printing. Examples of such a crosslinking agent include formaldehyde, glyoxal, polyisocyanate, an initial hydrolysis / condensate of tetraalkoxysilane, dimethylol urea and hexamethylol melamine.

Further, in order to improve the surface condition of the coating, the well-known fluorine-containing surfactant is added to the hydrophilic layer of the present invention.
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 0.1 to 3 μm.
m is preferable. More preferably 0.5 to 2μ
m. Within this range, the durability of the hydrophilic layer is ensured, and good printing durability during printing is obtained. If it is too thick, the hydrophilic layer will be ablated to separate from the ink receiving layer,
Expensive energy is required, and when exposing with a laser, it takes a long time to reduce the productivity of printing plates.

The heat-sensitive lithographic printing plate of the present invention may have a water-soluble overcoat layer on the hydrophilic layer. The overcoat layer can prevent the lipophilic substance from contaminating the hydrophilic layer and damaging the hydrophilic layer during storage and handling of the original printing plate. In addition, by including a photothermal conversion agent in the overcoat layer, it is possible to increase the sensitivity without adding a large amount of the photothermal conversion agent to the hydrophilic layer and deteriorating the hydrophilicity and film quality of the hydrophilic layer. .

The water-soluble overcoat layer that can be used in the present invention can be easily removed at the time of printing and contains a resin selected from water-soluble polymer compounds. As the water-soluble polymer compound used herein, a film formed by coating and drying has a film forming ability, and specifically, polyvinyl acetate (provided that the hydrolysis rate is 65% or more), polyacrylic Acid and its alkali metal salt or amine salt, acrylic acid copolymer and its alkali metal salt or amine salt, polymethacrylic acid and its alkali metal salt or amine salt, methacrylic acid copolymer and its alkali metal salt or amine salt, Acrylamide homopolymer and copolymer, polyhydroxyethyl acrylate, vinylpyrrolidone homopolymer and copolymer,
Polyvinyl methyl ether, vinyl methyl ether / maleic anhydride copolymer, poly-2-acrylamide-2
-Methyl-1-propanesulfonic acid and its alkali metal salt or amine salt, 2-acrylamido-2-methyl-1-propanesulfonic acid copolymer and its alkali metal salt or amine salt, gum arabic, cellulose derivatives (for example, , Carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, white dextrin, pullulan, enzymatically decomposed etherified dextrin and the like. Further, according to the purpose, two or more of these resins can be used in combination.

In addition, in the case of aqueous solution application, a nonionic surfactant can be mainly added to the overcoat layer in order to ensure uniformity of application. Specific examples of such a nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearate, polyoxyethylene nonylphenyl ether, and polyoxyethylene dodecyl ether. . 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.

The thickness of the overcoat layer according to the present invention is set to 0.1.
It is preferably from 0.5 to 4.0 μm, more preferably from 0.1 to 4.0 μm.
１．０1.0 μm. Within this range, it takes time to remove the overcoat layer during printing, or a large amount of dissolved water-soluble resin affects the dampening solution, causing roller strips during printing, and ink depositing on the image area. Good prevention of scattering of ablation scum and prevention of lipophilic substance contamination can be obtained without giving any adverse effects such as no abrasion and without impairing the film properties.

At least one of the ink receiving layer, hydrophilic layer and overcoat layer of the present invention contains a light-to-heat converting agent having a function of converting light into heat in order to increase sensitivity. As such a light-to-heat conversion agent, 700 to 1200 nm
Any pigment or dye may be used as long as it is a light absorbing substance having an absorption band in at least a part of the range.

As pigments, commercially available pigment and color index (CI) handbook, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986) And "printing ink technology" (CMC Publishing, 1984) can be used.

These pigments can be used after being subjected to a known surface treatment, if necessary, in order to improve the dispersibility in the layer to which the pigment is added. Surface treatment methods include a method of surface-coating a hydrophilic resin or a lipophilic resin, a method of attaching a surfactant, and a reactive substance (for example, silica sol, alumina sol, a silane coupling agent or an epoxy compound,
A method of bonding an isocyanate compound) to the surface of the pigment. The pigment to be added to the hydrophilic layer is preferably a pigment whose surface is coated with a hydrophilic resin or silica sol so as to be easily dispersed in a water-soluble resin and not to impair the hydrophilicity. 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. Among the pigments, a particularly preferred pigment is carbon black.

Examples of the dye include commercially available dyes and literatures (eg, “Dye Handbook” edited by The Society of Synthetic Organic Chemistry, 1975, “Chemical Industry”, May 1986, pp. 45-51, “Near-infrared absorbing dyes”). , "Development of functional dyes and market trends in the 1990s", Chapter 2, section 2.3 (CMC, 1990)
Alternatively, 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, for example, Japanese Patent Application Laid-Open No. 58-12524
No. 6, JP-A-59-84356, JP-A-60-787
No. 87, etc .;
Methine dyes described in JP-A-173696, JP-A-58-181690, JP-A-58-194595, and the like; JP-A-58-112793, JP-A-58-22
No. 4793, JP-A-59-48187, JP-A-59-48187.
73996, JP-A-60-52940, JP-A-60-52940
Naphthoquinone dyes described in US Pat.
Squarylium dyes described in JP-A-58-112792, cyanine dyes described in British Patent 434,875, dyes described in U.S. Pat. No. 4,756,993, and U.S. Pat. No. 4,973,572. And the dyes described in JP-A-10-268512.

As a dye, US Pat.
No. 938 is also preferably used, and substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 3,881,924;
No. 42645 (U.S. Pat. No. 4,327,169), a trimethinethiapyrylium salt described in JP-A-58-1810.
No. 51, No. 58-220143, No. 59-41363
Nos. 59-84248, 59-84249, 59-146063, and 59-146061 and pyrylium compounds described in JP-A-59-2161.
No. 46, a cyanine dye disclosed in U.S. Pat. No. 4,283,4.
No. 75, pentamethine thiopyrylium salt and the like, and pyrilium compounds described in Japanese Patent Publication Nos. 5-135514 and 5-19702;
178, Epolite III-130, Epolite III-12
5 and the like are also preferably used. 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 thereof are listed below by structural formulas.

[0067]

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[0068]

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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 cyanine dyes exemplified below.

[0070]

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When the photothermal conversion agent is added to the ink receiving layer, it is preferably 20% by weight or less, more preferably 15% by weight or less of the solid content of the ink receiving layer. Within this range, without impairing the durability of the ink receiving layer,
Good sensitivity is obtained.

When the light-to-heat converting agent is added to the hydrophilic layer, it is added in an amount of 1 to 40% by weight, preferably 2% by weight, based on the solid content of the hydrophilic layer.
-20% by weight. Within this range, good sensitivity can be obtained without impairing hydrophilicity or durability.

When the light-to-heat converting agent is added to the overcoat layer, the ratio of addition is from 1 to 70% of the solid content of the overcoat layer.
%, Preferably 2 to 50% by weight, more preferably 2 to 30% by weight when the light-to-heat conversion agent is a dye, and particularly preferably 20 to 50% by weight when the light-to-heat conversion agent is a pigment. Within this range, good sensitivity can be obtained without impairing the uniformity and film strength of the overcoat layer. When a light-to-heat conversion agent is added to the overcoat layer, the addition amount of the light-to-heat conversion agent in the ink receiving layer and the hydrophilic layer can be reduced or not added depending on the addition amount.

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 further processing. When printing is started using the ink and the fountain solution, the ink is deposited on the exposed portion of the ink receiving layer where the hydrophilic layer has been removed, and printing proceeds. The overcoat layer is quickly dissolved and removed by contact with the dampening solution, and hardly affects printing. Also, the lithographic printing plate of the present invention, after being mounted on a printing press cylinder,
It is also possible to expose by a laser mounted on a printing press, and then apply on a fountain solution and / or ink for on-press development.

[0075]

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

Production Example of Aluminum Substrate A JISA1050 aluminum material containing 99.5% by weight of aluminum, 0.01% by weight of copper, 0.3% by weight of iron, 0.03% by weight of titanium, and 0.1% by weight of silicon was used. The surface of the 0.24 mm-thick rolled plate was grained using a 400-mesh 20% by weight aqueous suspension of pamistone (manufactured by Kyoritsu Ceramics) and a rotating nylon brush, and then thoroughly washed with water. This was immersed in a 15% by weight aqueous sodium hydroxide solution (containing 4.5% by weight of aluminum), etched so that the amount of aluminum dissolved was 10 g / m ² , and washed with running water. Further, the mixture was neutralized with a 1% by weight nitric acid aqueous solution, and then, in a 0.7% by weight nitric acid aqueous solution (containing 0.5% by weight of aluminum), a rectangular wave alternating voltage of 10.5 V at the time of anode and 9.3 V at the time of cathode was used. Waveform voltage (current ratio r = 0.
90, using an electric current waveform described in Examples of JP-B-58-5796), and an electrolytic surface-roughening treatment was carried out at 230 C / dm ² of electricity at the time of anode. After washing with water, it was immersed in a 10% by weight aqueous solution of sodium hydroxide at 35 ° C., and etched so that the amount of aluminum dissolved was 1 g / m ² .
Washed with water. Next, it was immersed in a 30% by weight aqueous sulfuric acid solution at 50 ° C., desmutted, and washed with water. In addition, 35 ° C
Anodizing treatment was performed in a 20% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) using a direct current. That performs electrolysis at a current density of 13A / dm ^2, by adjusting the electrolysis time, a substrate of anodized film weight 2.0g / m ² (A), the substrate of ^{3.0g / m 2 (B),} 4.0g / M ²
And a substrate (D) of 5.0 g / m ² .

Production Example 1 of Lithographic Printing Raw Material The substrate (B) was immersed in an aqueous solution of sodium hydroxide at 30 ° C. and pH 13 until the film dissolution amount was 1 g / m ^2, and then washed with water. After this pore widening treatment, 100 ° C, 1
The aluminum support was made by sealing for 12 seconds in a steam chamber saturated at atmospheric pressure. An ink receiving layer coating solution I-1 having the following composition was coated on this support with a bar coater so that the coating solution amount was 12 ml / m ² . Thereafter, it was dried by heating at 100 ° C. for 1 minute to obtain an ink receiving layer having a dry coating amount of about 0.5 g / m ² .

(Ink receiving layer coating liquid I-1) Epicoat 1010 3 g Photothermal conversion agent (IR-24 described in this specification) 0.3 g Methyl ethyl ketone 32.7 g Propylene glycol monomethyl ether 30 g

Here, the epicoat 1010 has a softening point of 1
69 ° C epoxy resin (manufactured by Yuka Shell Epoxy)
It is.

The following hydrophilic layer coating solution S-1 was coated on the ink receiving layer thus provided,
After drying for 1 minute, a heat-sensitive planographic printing plate having a hydrophilic layer dry coating amount of 0.6 g / m ² was obtained.

(Hydrophilic Layer Coating Solution S-1) 10% by weight methanol solution of novolak resin (N1) 0.5 g methanol silica 3.17 g methyl lactate 0.5 g methanol 15.83 g

The novolak resin (N1) used here was
It is an addition condensate of a mixture of m-cresol and p-cresol at a weight ratio of 6/4 and paraformaldehyde, and has a weight average molecular weight of 3,500. Methanol silica is a colloid composed of a methanol solution containing 30% by weight of silica having a particle size of 10 to 20 nm, manufactured by Nissan Chemical Industries.

On the hydrophilic layer, an overcoat layer coating solution OC-1 having the following composition was applied and dried at 100 ° C. for 90 seconds to form a thermosensitive layer having an overcoat layer having a dry coating weight of 0.25 g / m ² . A lithographic printing original plate-1 was produced.

(Overcoat Layer Coating Solution OC-1) 5% aqueous solution of gum arabic 10 g Photothermal conversion agent (dye IR-10 described in this specification) 0.2 g Polyoxyethylene nonylphenyl ether 0.02 g Water 14 g

Preparation Example 2 of Lithographic Printing Plate Heat-sensitive lithographic printing was performed in the same manner as in Preparation Example 1 of the lithographic printing plate except that the sealing treatment time during the production of the support was changed from 12 seconds to 50 seconds. A master plate-2 was prepared.

Production Example 3 of Lithographic Printing Plate The same heat-sensitive method as that of Production Example 1 of the planographic printing plate except that the substrate D was used in place of the substrate B and the sealing time was changed from 12 seconds to 15 seconds. A lithographic printing original plate-3 was produced.

Preparation Example 4 of Lithographic Printing Plate Except that Substrate D was used in place of Substrate B, the same process was performed as in Preparation Example 2 of the lithographic printing plate precursor.
4 was produced.

Production example of a lithographic printing plate precursor for comparison A production of the lithographic printing plate precursor described above except that the substrate (A) was used instead of the substrate (B) and the pore widening treatment with an aqueous sodium hydroxide solution was not performed. As in Example 1,
A lithographic printing plate-A for comparison was prepared.

Production example of a lithographic printing plate precursor for comparison B Production example of a lithographic printing plate precursor except that the substrate (C) was used in place of the substrate (D) and the pore widening treatment with an aqueous sodium hydroxide solution was not performed. In the same manner as in Example 3, a lithographic printing original plate-B for comparison was prepared.

Production Example of Comparative Lithographic Printing Plate C A comparative lithographic printing substrate was prepared in the same manner as in Preparation Example 1 of the lithographic printing plate except that the sealing treatment was not performed.

Production Example of Comparative Lithographic Printing Raw Material (d) A comparative lithographic printing original plate- (d) was prepared in the same manner as in Production Example 3 of the lithographic printing original plate except that the sealing treatment was not performed.

Examples 1 to 4 and Comparative Examples 1 to 4 The heat-sensitive lithographic printing original plates obtained as described above were exposed with a trend setter (a plate setter equipped with a 40 W 830 nm semiconductor laser) manufactured by Creo Corporation. . The exposed original plate was attached without further processing to a printing machine Lithrone manufactured by Komori Corporation, and a plate etch solution EU-3 (manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol (volume ratio 1/99/10) ) And Geos G ink (manufactured by Dainippon Ink and Chemicals, Inc.). From the results, an appropriate amount of exposure energy (sensitivity) was determined and is shown in Table 1. Table 1 shows the number of printable sheets (the number of printable sheets) and the observation results of print stains when exposed with this proper exposure energy amount, along with the amount of anodic oxidation, the presence or absence of pore wide processing, the sealing processing time, and the sealing ratio. Indicated.

[0093]

[Table 1]

Example 5 and Comparative Example 5 A substrate (A) having an anodic oxide film amount of 2.0 / m ² was subjected to the same pore widening treatment and water washing as in Production Example 1 of a lithographic printing plate precursor, and then 100 ° C. A sealing treatment was performed for 50 seconds in a steam chamber saturated at 1 atm.
A 0% aluminum support was made. The same ink receiving layer as in Production Example 1 was provided on this support. Further, the following hydrophilic layer coating solution S-2 was applied thereon to provide a hydrophilic layer having a dry coating amount of 0.6 g / m ² .

(Hydrophilic Layer Coating Solution S-2) Methanol silica (same as in Example 1) 3.33 g Methyl lactate 0.5 g Methanol 16.17 g

On the hydrophilic layer, an overcoat layer coating solution OC-2 having the following composition was applied and dried at 100 ° C. for 90 seconds to obtain a heat-sensitive layer having an overcoat layer having a dry coating weight of 0.25 g / m ² . A lithographic printing original plate-5 was produced.

(Overcoat Layer Coating Solution OC-2) Polyacrylic acid (weight average molecular weight 50,000) 0.5 g Light-to-heat converting agent (dye IR-11 described in this specification) 0.2 g Polyoxyethylene nonyl phenylate Tail 0.04g Water 19g

This heat-sensitive lithographic printing original plate-5 was exposed and printed in the same manner as in Example 1. The optimal exposure energy is 1
At 70 mJ / m ² , 10,000 good printed matters were obtained.
The optimum exposure energy of the comparative heat-sensitive lithographic printing plate-e (Comparative Example 5) produced in the same manner as in Example 5 except that the pore wide treatment was not performed was 250 mJ / m ² ,
The number of printings was 10,000.

Example 6 On the aluminum substrate having the same ink receiving layer as prepared in Example 5, the following hydrophilic layer coating solution S-3 was used.
A hydrophilic layer having a dry coating amount of 0.6 g / m ² was provided.

(Hydrophilic Layer Coating Solution S-3) Alumina Sol 100 1 g Methanol Silica 2.83 g Poly-2-hydroxyethyl methacrylate 0.5 g Methyl lactate 0.5 g Methanol 15.17 g

Here, the alumina sol 100 is a water-dispersed colloid containing 10% by weight of 10 × 100 nm feathered alumina particles manufactured by Nissan Chemical Co., and poly-2-hydroxyethyl methacrylate has a weight average molecular weight of 300,000 and a 10% by weight methanol solution. It is.

The overcoat layer used in Example 5 was provided on the hydrophilic layer in the same manner as in Example 5 to produce a heat-sensitive lithographic printing original plate-6. The optimum exposure energy of this heat-sensitive lithographic printing plate was 150 mJ / m ² , and 10,000 good printed matters were obtained.

Example 7 The following hydrophilic layer coating solution S-4 was used in place of the hydrophilic layer coating solution S-3 of Example 6. Otherwise in the same manner as in Example 6, a heat-sensitive lithographic printing original plate-7 having an overcoat containing a photothermal conversion agent was produced.

(Hydrophilic Layer Coating Solution S-4) Poly-2-hydroxyethyl methacrylate 0.5 g Alumina Sol 520 4.75 g Methyl lactate 0.5 g Methanol 14.25 g

Here, poly-2-hydroxyethyl methacrylate is the same 10% by weight methanol solution as in Example 6, and alumina sol 520 is a water-dispersed colloidal solution containing 20% by weight of alumina particles having a particle diameter of 10 to 20 nm (Nissan). Chemical). This heat-sensitive planographic printing plate-7 is
Exposure and printing were performed in the same manner as in Example 1. The optimum exposure energy was 150 mJ / m ² , and 10,000 good prints were obtained.

Example 8 Coating of an ink-receiving layer containing the following photothermal conversion agent on an aluminum support having the same anodic oxide film amount of 2.0 g / m ² , pore-wide treatment and 100% sealing rate as in Example 5 Liquid I
-2, an ink receiving layer having a dry coating amount of 0.5 g / m ² was provided.

(Ink receiving layer coating liquid I-2) Phenothote YP-50 (Phenoxy resin manufactured by Toto Chemical Co.) 3.0 g Light-to-heat converting agent (Dye IR-24 described in this specification) 0.3 g Methyl ethyl ketone 32.7 g Propylene Glycol monomethyl ether 30g

A hydrophilic layer having a dry coating amount of 0.6 g / m ² was provided on the ink receiving layer using the following hydrophilic layer coating solution S-5. Further, an overcoat layer was further formed thereon by using the following coating solution OC-3, and a dry coating weight of 0.25 g / m ^2.
To prepare a heat-sensitive lithographic printing original plate-8.

(Hydrophilic Layer Coating Solution S-5) Methanol Silica 3.33 g Photothermal Conversion Agent (Dye IR-10 described in this specification) 0.1 g Methyl lactate 0.5 g Methanol 16.07 g

(Overcoat Layer Coating Solution OC-3) Gum Arabic 5% aqueous solution 10 g White dextrin 5% aqueous solution 10 g Polyoxyethylene nonylphenyl ether 0.04 g Light-to-heat converting agent (dye IR-11 described in this specification) 0 .2g water 4g

This heat-sensitive lithographic printing original plate-8 was exposed and printed in the same manner as in Example 1. The optimal exposure energy is 1
At 20 mJ / m ² , 10,000 good printed matters were obtained.

Example 9 On the ink receiving layer obtained in the same manner as in Preparation Example 2 of a lithographic printing plate precursor, the following hydrophilic layer coating solution S-6 was used, and the dry coating amount was 0.1%.
Heat-sensitive lithographic printing plate having a hydrophilic layer of 6 g / m ² -9
Was prepared.

(Hydrophilic Layer Coating Solution S-6) Poly-2-hydroxyethyl methacrylate (10 wt% methanol solution) 0.5 g Alumina sol 520 4.75 g Photothermal conversion agent (Dye IR-11 described in this specification) 09g methyl lactate 0.5g methanol 14.25g

This lithographic printing original plate-9 was exposed and printed in the same manner as in Example 1. Optimal exposure energy is 100m
At J / m ² , 10,000 good printed matters were obtained.

[0115]

According to the present invention, a heat-sensitive lithographic plate having an aluminum plate as a support can be directly mounted on a printing machine for printing after exposure without any processing, and has improved sensitivity. An original plate for printing is obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AB03 AC08 AD01 AD03 CC20 DA18 DA20 DA36 EA01 FA03 2H096 AA07 AA08 BA16 BA20 CA03 CA05 CA20 LA16 2H114 AA22 AA24 BA01 DA04 DA15 DA25 DA26 DA46 DA52 DA55 DA73 DA03 EA02 FA16 GA08 GA09 GA34 GA38

Claims (2)

[Claims] 1. On an aluminum support a) an ink receiving layer and b) selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. A heat-sensitive lithographic printing plate precursor having a hydrophilic layer containing a colloidal particulate oxide or hydroxide of at least one element, wherein at least one of the ink-receiving layer and the hydrophilic layer contains a light-to-heat conversion agent. A heat-sensitive lithographic plate, wherein the aluminum support has an anodized film of ² g / m ² or more, and has been subjected to a pore widening treatment and a sealing treatment with a sealing ratio of 50% or more. Original plate for printing. 2. An ink-receiving layer, a hydrophilic layer and a water-soluble overcoat having, on an aluminum support, a) an ink-receiving layer, b) a hydrophilic layer according to claim 1, and c) a water-soluble overcoat layer. At least one of the layers is a heat-sensitive planographic printing plate containing a photothermal conversion agent, wherein the aluminum support has an anodized film of ² g / m ² or more, a pore widening treatment, and a sealing. A heat-sensitive lithographic printing plate, which has been subjected to a sealing treatment with a porosity of 50% or more.