JP2001096938A - Original plate for heat-sensitive lithographic printing block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an original plate for a heat-sensitive lithographic printing to be mounted directly on a printer without the development after the exposure and provided with superior resistance to printing and hardly generating printing scum. SOLUTION: An original plate for a heat-sensitive lithographic printing block is provided with (a) an ink acceptive layer containing a photothermic conversion agent and (b) a hydrophilic layer coated with a solution, which contains colloid of an oxide or a hydroxide of at least one element selected out of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and a transition metal and also a hydrophilic resin, and formed successively in the above order on a substrate.

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 precursor which does not require development and is excellent in printing durability and stain resistance. More specifically, image recording by infrared or near-infrared laser beam scanning exposure based on a digital signal is possible, and the recorded image is directly mounted on a printing machine and printed without going through a conventional developing process. Lithographic printing plate precursor capable of

[0002]

2. Description of the Related Art Various methods have been proposed for a lithographic printing plate precursor that can be formed on a printing press without forming an image by forming an image by heat. One of the promising methods is a method using ablation in which exposure is performed with a solid-state high-output infrared laser such as a semiconductor laser or a YAG laser, and the exposed portion is heated with a photothermal conversion agent to cause decomposition and evaporation. That is, this is a method in which a hydrophilic layer is provided on a lipophilic substrate or a substrate having a lipophilic layer, and the hydrophilic layer is ablated and removed imagewise.

[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 polyvinyl alcohol has a hydrocarbon group and is not necessarily highly hydrophilic, it occupies as much as 48% by weight of the solid content of the hydrophilic layer. Therefore, the stain resistance is insufficient, and further improvement is required.

[0004] WO98 / 40212, WO99 /
JP-A-19143 and WO99 / 19144 disclose that a hydrophilic layer mainly composed of a colloid such as silica cross-linked with a cross-linking agent such as aminopropyltriethoxysilane is provided on a substrate coated with an ink-receiving layer. 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. However, the printing durability is insufficient for several thousand sheets.

[0005] A digital direct non-process printing plate utilizing ablation can be made directly from under the printing plate without using a film, and can be directly mounted on a printing machine and printed immediately. It has the major advantage of streamlining and reducing waste, but because of the difficulty of the technology without treatment, it tends to impair the basics of printing, such as stain resistance or printing durability, and a technology that balances both. Has not been developed.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems. That is, it is an object of the present invention to provide a heat-sensitive lithographic printing plate precursor that can be directly mounted on a printing machine for printing without performing processing, has excellent printing durability, and is less likely to cause printing stains.

[0007]

The inventor of the present invention has developed a new excellent hydrophilic layer to solve the above-mentioned problems, so that the present invention can be applied to a printing machine without any treatment, and the printability, especially the resistance to printing, can be improved. The present inventors have found that a heat-sensitive lithographic printing plate precursor excellent in printing power and stain resistance can be obtained, and have accomplished the present invention. That is, the present invention is as follows.

[0008] 1. A) an ink-receiving layer containing a photothermal conversion agent, b) beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin,
A hydrophilic layer formed by applying a solution containing an oxide or hydroxide colloid of at least one element selected from zirconium, iron, vanadium, antimony, and a transition metal and a hydrophilic resin, is provided in this order. Original plate for lithographic printing plate.

[0009] 2. The hydrophilic resin has a hydrophilic layer solid content of 0.1%.
2. The heat-sensitive lithographic printing plate precursor as described in 1 above, wherein the amount is from 30 to 30% by weight.

[0010] 3. 2. The heat-sensitive lithographic printing plate precursor as described in 1 above, wherein the hydrophilic resin is a polymer compound having a hydroxy group or a carboxy group. 4. 2. The heat-sensitive lithographic printing plate precursor as described in 1 above, wherein the hydrophilic resin is a homopolymer or a copolymer of hydroxyalkyl acrylate or hydroxyalkyl methacrylate.

5. 2. The heat-sensitive lithographic printing plate as described in 1 above, wherein the colloid is a sol comprising a hydrolyzed condensate of at least one compound selected from di, tri and / or tetraalkoxy silicon, tetraalkoxy aluminum, tetraalkoxy titanium and tetraalkoxy zirconium. Original plate.

[0012]

Embodiments of the present invention will be described below in detail.

[0013] The hydrophilic layer used in the present invention is an oxide of at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. Alternatively, it is formed by applying a solution containing a hydroxide colloid and a hydrophilic resin. Aluminum, silicon, titanium and zirconium are preferred as the elements constituting the colloidal oxide or hydroxide used in the present invention, and silicon is particularly preferred.

The colloid particles used in the present invention generally have a particle size of 2 nm to 500 nm, and 5 nm for silica.
Spherical ones of m to 100 nm are preferred in the present invention. Spherical particles of 10 nm to 50 nm have a diameter of 50 nm to 4
A pearl neck-shaped colloid having a length of 00 nm can also be used. Further, feather-like materials such as 100 nm × 10 nm like aluminum 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 of the above elements. Dispersions of these colloids are available from Nissan Chemical Industries, Ltd.
You can also purchase commercial products such as.

As the hydrophilic resin used in the hydrophilic layer of the present invention, those having a hydrophilic group such as hydroxy, carboxy, hydroxyethyl, hydroxypropyl, amino, aminoethyl, aminopropyl and carboxymethyl are preferred. 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 acid And salts thereof, polymethacrylic acid and salts thereof, a homopolymer or copolymer of hydroxyethyl methacrylate, a homopolymer or copolymer of hydroxyethyl acrylate, a homopolymer or copolymer of hydroxypropyl methacrylate, hydroxy Homopolymer or copolymer of propyl acrylate, homopolymer or copolymer of hydroxybutyl methacrylate, homopolymer or copolymer of hydroxybutyl acrylate, polyethylene glycol, polypropylene glycol Coal, polyvinyl alcohol, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, homopolymers and copolymers of acrylamide, homopolymers and polymers of methacrylamide, having a degree of hydrolysis of at least 60% by weight, preferably at least 80% by weight, Examples include homopolymers and copolymers of N-methylolacrylamide.

Particularly preferred hydrophilic resins are hydroxy- or carboxy-containing polymers, of which hydroxy-containing polymers are particularly preferred. Specifically, a homopolymer or copolymer of hydroxyethyl acrylate or hydroxyethyl methacrylate is most suitable.

The proportion of these hydrophilic resins to be added is preferably 1 to 30% by weight, more preferably 5 to 20% by weight based on the total solid content of the hydrophilic layer. When the amount is smaller than this range, the printing durability is not sufficient, and when the amount is larger than this range, printing stains are likely to occur.

In the hydrophilic layer of the present invention, in addition to the above-mentioned colloid and hydrophilic resin, a crosslinking agent for accelerating crosslinking of colloid and / or a crosslinking agent for hydrophilic resin may be added to enhance printing durability. Good.

The colloid crosslinking agent is preferably an initial hydrolysis condensate of tetraalkoxysilane, trialkoxysilylpropyl-N, N, N-trialkylammonium halide or aminopropyltrialkoxysilane. It is preferable that the addition ratio is 5% by weight or less of the total solid content of the hydrophilic layer.

Examples of the crosslinking agent for the hydrophilic resin include formaldehyde, glyoxal, polyisocyanate, initial hydrolysis and condensate of tetraalkoxysilane, dimethylol urea and hexamethylol melamine.

The hydrophilic layer according to the present invention may further include a well-known fluorine-based surfactant for improving the surface condition 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. More preferably, 0.
It is 5 μm to 2 μm. If it is too thin, the durability of the hydrophilic layer will be poor, and the printing durability during printing will be poor. If it is too thick, a large amount of energy is required to ablate the hydrophilic layer from the underlying ink receiving layer, and a long drawing time is required when exposing with a laser. Is reduced. When drawn using a general commercially available semiconductor laser, a thickness of about 0.5 μm and a thickness of 300 to 40
The energy of 0 mJ / cm ^2, requiring energy 400~500mJ / cm ² at a thickness of about 1.5 [mu] m.

The ink receiving layer of the present invention is obtained by applying a coating liquid containing an organic polymer having a lipophilic film-forming ability and a photothermal conversion agent as main components to the surface of a substrate.

The organic polymer must be soluble in the coating solvent for the ink receiving layer, but is preferably insoluble in the coating solvent for the upper hydrophilic layer. However, those which partially swell in the coating solvent of the upper layer are sometimes excellent in the adhesiveness to the upper layer and may be desirable. In addition, when an organic polymer soluble in the upper layer coating solvent is used, it is desirable to cure the organic polymer in advance by adding a crosslinking agent or the like.

Examples of 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. , Polyvinylphenol, polyvinylhalogenated phenol, methacrylic resin and its copolymer, acrylamide copolymer, methacrylamide copolymer, polyvinylformal, polyamide, polyvinylbutyral, polystyrene, cellulose ester resin, polyvinyl chloride and polyvinylidene chloride And the like. Among these, as a more preferred compound, a resin having a hydroxy group, a carboxy group, a sulfonamide group or a trialkoxysilyl group in a side chain is excellent in adhesiveness to a substrate or an upper hydrophilic layer, and optionally a crosslinking agent. It is desirable because it cures easily. In addition, an acrylonitrile copolymer, a polyurethane, a copolymer having a sulfonamide group in a side chain, or a copolymer having a hydroxy group in a side chain is preferably photocured with a diazo resin.

Other phenol, cresol (m-cresol, p-cresol, m / p mixed cresol), phenol / cresol (m-cresol, p-cresol, m / p mixed cresol), phenol-modified xylene, tert-butylphenol, A novolak resin and a resole resin of condensation with formaldehyde such as octylphenol, resorcinol, pyrogallol, catechol, chlorophenol (m-Cl, p-Cl), bromophenol (m-Br, p-Br), salicylic acid, and phloroglucinol; Further, a condensation resin of the above phenol compound and acetone is useful.

As other suitable high molecular compounds, there can be mentioned copolymers having a molecular weight of usually 10,000 to 200,000 using the monomers shown in the following (1) to (12) as constituent units.

(1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxy group, such as N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxy Phenyl) methacrylamide, o-, m- and p-hydroxystyrene, o
-, M- and p-hydroxyphenyl acrylates or methacrylates, (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, 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
Acrylamides such as -phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide Or methacrylamide, (6) ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether,
Vinyl ethers such as 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) methyl vinyl ketone and ethyl Vinyl ketones such as vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone, (1
0) olefins such as ethylene, propylene, isobutylene, butadiene, 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 light-to-heat converting agent contained in the ink receiving layer of the present invention for increasing the heat sensitivity is 700 to 120.
Any substance that absorbs light of 0 nm may be used, and various pigments and dyes can be used. Examples of pigments include commercially available pigment and color index (C.I.) handbook, "Latest Pigment Handbook" (edited by Japan Pigment Technology 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 being subjected to a surface treatment, or may be used after being subjected to a surface treatment in order to increase the affinity with an organic polymer having a lipophilic film-forming ability. Examples of the surface treatment include a method of surface-coating a lipophilic resin, a method of attaching a surfactant, and a method of applying a reactive substance (eg, silica sol, alumina sol, a silane coupling agent, an epoxy compound, an isocyanate compound, etc.) to the pigment surface. There are methods of bonding, etc., “Properties and Applications of Metallic Soap” (Koshobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986).
Annual).

Of these pigments, those absorbing infrared or near infrared rays are preferred in that they are suitable for use with lasers that emit infrared or near infrared rays. A particularly preferred pigment is carbon black.

As the dye, commercially available dyes and known dyes described in literatures (for example, "Dye Handbook" edited by The Society of Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, and cyanine dyes. Among these dyes, those that absorb infrared light or near-infrared light are particularly preferable because they are suitable for use in lasers that emit infrared or near-infrared light.

Examples of dyes that absorb infrared or near-infrared rays include, for example, JP-A-58-125246 and JP-A-59-8.
4356, a cyanine dye described in JP-A-60-78787, a methine dye described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc. JP-A-58-1127
No. 93, JP-A-58-224793, and JP-A-59-4
No. 8187, JP-A-59-73996, JP-A-60-
No. 52940, JP-A-60-63744 and the like; naphthoquinone dyes described in JP-A-58-112792 and the like; British Patent 43
Cyanine dyes described in U.S. Pat.
6,993, U.S. Pat. No. 4,973,57
The cyanine dye described in No. 2 and the dye described in JP-A-10-268512 can be exemplified.

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 (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 disclosed in Japanese Patent Publication Nos. 5-135514 and 5-19702, Epolig manufactured by Eporin Co.
ht III-178, Epollight III-130, E
Polit III-125 and the like are also preferably used.
Among these dyes, particularly preferred specific examples are listed below by structural formulas.

[0040]

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[0041]

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[0042]

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[0043]

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The addition ratio of the photothermal conversion agent to the ink receiving layer is preferably 1 to 40% by weight of the total amount of the ink receiving layer, particularly preferably 20 to 35% by weight for pigments and 5 to 15% for dyes. % By weight. If the amount of the pigment or dye is less than the above range, the sensitivity is lowered. If the amount is more than the above range, the durability of the layer is reduced.

In the ink receiving layer, in addition to the organic polymer and the light-to-heat converting agent, a crosslinking agent, an adhesion auxiliary agent, a coloring agent, an inorganic or inorganic material, for improving the film quality of the ink receiving layer and improving the appearance. Organic fine particles, coating surface condition improvers or plasticizers can be added. Further, a heating color developing system or a decoloring system for forming a printout image after exposure may be added.

Examples of a crosslinking agent for crosslinking an organic polymer include diazo resins, aromatic azide compounds, epoxy resins, isocyanate compounds, blocked isocyanate compounds, initial hydrolysis condensates of tetraalkoxy silicon, glyoxal, aldehyde compounds and methylol compounds. be able to.

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

As the coloring agent, ordinary dyes and pigments can be 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. 7-335.
No. 145 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 adjusting the state of the coated surface.

Examples of the inorganic or organic fine powder which can be used in the present invention include colloidal silica and colloidal aluminum having a diameter of 10 nm to 100 nm, and inert particles having a particle size larger than those of colloids, such as silica particles, surface hydrophobic particles. Silica particles, alumina particles, titanium dioxide particles, other heavy metal particles, clay and talc. 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 in the ink receiving layer is 80% by weight or less, preferably 40% by weight or less of the total amount.

Further, a plasticizer may be added to the ink receiving layer of the present invention, if necessary, 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 that a color-forming or decoloring compound is added to the ink-receiving layer of the present invention in order to sharpen an image area and a non-image area when exposed. For example, together with thermal acid generators such as diazo compounds and diphenyliodonium salts, leuco dyes (leucomalachite green, leuco crystal violet, lactones of crystal violet, etc.) and PH discoloration dyes (eg, ethyl violet, Victoria Poor Blue BOH, etc.) Dye) 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 systems is 10% by weight or less, preferably 5% by weight or less based on the total amount in the 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, ethylene glycol monomethyl monoacetate, etc.), amides (formamide, N-methylformamide, pyrrolidone, N-methylpyrrolidone, etc.), gamma-butyrolactone, methyl lactate, ethyl lactate, etc. it can. 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 may be 0.1 μm or more. When it is provided on a metal plate, it has a role as a heat insulating layer, so that it is preferably 0.5 μm or more. If the ink receiving layer is too thin, the heat generated will dissipate toward the metal plate, lowering the sensitivity. In addition, in the case of a hydrophilic metal plate, the ink receiving layer is required to have abrasion resistance, so that the printing durability cannot be ensured. When a lipophilic plastic film is used as the substrate, the ink receiving layer only has to function as an adhesive layer with the upper layer, so the coating amount may be smaller than that of the metal plate, and may be 0.05 μm. The above is preferred.

As the substrate on which the ink receiving layer used in the present invention is applied, a dimensionally stable plate is used.
Paper, paper laminated with lipophilic plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, nickel, stainless steel plate, etc.), plastic film (eg, cellulose diacetate, Cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate,
Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or vapor-deposited.

Preferred substrates are polyethylene terephthalate film, polycarbonate film, aluminum or steel plate, or aluminum or steel plate laminated with lipophilic plastic film.

As the aluminum plate used in the present invention, an aluminum plate of a conventionally known and used material can be appropriately used.

Prior to using the aluminum plate, it is preferable to roughen the surface. When an ink receiving layer made of an organic polymer is applied by roughening, adhesion to a substrate can be easily secured. For the surface roughening, a known and used aluminum plate surface treatment technique can be used.

The heat-sensitive lithographic printing plate of the present invention absorbs lipophilic components in the air when the plate is stored for a long period of time or around a printing machine before printing, or when the plate is handled. Smears may occur during printing, for example, by touching with ink-stained fingers. Further, in ablation, there is a problem in that the plate setter optical system and the like are contaminated by scattered matter that has been decomposed and removed. An overcoat layer made of a water-soluble resin can be provided on the hydrophilic layer in order to prevent such a printing stain problem and to suppress scattering of scum due to exposure ablation.

The water-soluble overcoat layer used in the present invention has a film-forming ability and can be easily removed at the time of printing, such as a resin selected from water-soluble polymer compounds, for example, a polyacrylic acid copolymer and its alkali. The main component is a metal salt or an amine salt.

To the overcoat layer, a nonionic surfactant such as polyoxyethylene nonyl phenyl ether is added for the purpose of ensuring uniformity of coating.

Further, a light-to-heat converting agent may be added to the overcoat layer of the present invention in order to increase the heat sensitivity. As the photothermal conversion agent that can be added to the overcoat layer, the above-mentioned infrared absorbing pigment or dye may be used, but carbon black subjected to hydrophilization treatment or a water-soluble dye is preferable.

The pigment or dye is used in an amount of 1 to 70% by weight, preferably 2 to 50% by weight, based on the total solid content of the overcoat layer, particularly preferably 2 to 30% by weight in the case of a dye, and particularly preferably 2 to 30% by weight in the case of a pigment. 20 to 50% by weight. In the present invention, since the photothermal conversion agent is added to the ink receiving layer, when the photothermal conversion agent is added to the overcoat layer, the amount thereof can be set as small as necessary.

The thickness of the overcoat layer used in the present invention is preferably from 0.05 μm to 4.0 μm, and more preferably from 0.1 μm to 1.0 μm. If it is too thick,
It takes time to remove the overcoat layer during printing,
In addition, a large amount of dissolved water-soluble resin affects the dampening solution, causing adverse effects such as the occurrence of roller strips during printing and the insufficiency of ink on the image area. If it is too thin, the film properties may be impaired.

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 master 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 ink receiving layer in the exposed portion, and printing is started.

[0066]

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 (Coating of ink receiving layer) An aluminum plate (grain JIS) subjected to graining, anodic oxidation and sodium silicate solution treatment
A1050, thickness 0.24 mm), a coating solution for the ink receiving layer having the following composition was applied so as to be 20 ml / m ² , and 1
Dry at 00 ° C for 1 minute, dry coating weight about 0.6g / m
An aluminum substrate having an ink receiving layer of No. ² was obtained. (Formulation of coating liquid for ink receiving layer) N- (p-aminosulfonylphenyl) methacrylamide / methyl methacrylate / acrylonitrile / 2-hydroxyethyl methacrylate (40/10/30/20 wt% copolymer) 3 g Dye (I-13) described in the description 1.3 g Ethylene glycol monomethyl ether 50 g Methyl ethyl ketone 47 g

(Preparation of heat-sensitive lithographic printing plate) Poly-2
-Hydroxyethyl methacrylate (weight average molecular weight 2
50,000) of a 10% ethylene glycol monomethyl ether solution, methanol silica (Nissan Chemical: 1
3 g of a methanol solution containing 30% by weight of 0 to 20 nm silica particles containing 30% by weight of silica particles and methanol 1
6 g of the solution was applied on the substrate coated with the ink receiving layer, and dried at 100 ° C. for 1 minute to provide a hydrophilic layer having a dry coating weight of about 1 g / m ² , thereby obtaining a heat-sensitive lithographic printing plate. .

(Preparation of lithographic printing plate) The above lithographic printing plate was used as a 40 W trend setter (40
A 830 nm W semiconductor laser was mounted on a mounting plate setter) and exposed with an energy of 400 mJ / cm ² . The exposed base plate was attached to a Komori Sprint Printer without any processing, and printed with a dampening solution and ink containing a 10% by volume aqueous solution of isopropyl alcohol containing an etchant. Prints were obtained.

Example 2 The same aluminum plate as that of Example 1 (material: JISA105)
0, a thickness of 0.24 mm) was coated with a coating liquid for an ink receiving layer in which carbon black having the following composition was dispersed.
° C., dried for 1 minute, to obtain an aluminum substrate having an ink-receiving layer having a dry coating weight of about 1 g / m ^2. (Composition of coating solution for ink receiving layer) N- (p-aminosulfonylphenyl) methacrylamide / methyl methacrylate / acrylonitrile / 2-hydroxyethyl methacrylate (40/10/30/20% by weight copolymer) 4 g carbon black 2 g Ethylene glycol monomethyl ether 70 g Methyl ethyl ketone 65 g On this substrate, the same hydrophilic layer as in Example 1 was provided to obtain a heat-sensitive lithographic printing original plate. When this original plate was exposed and printed in the same manner as in Example 1, 10,000 copies of a good printed matter free of stains were obtained.

Example 3 A heat-sensitive lithographic printing plate precursor was obtained in the same manner as in Example 1 except that the aminosulfonylphenyl methacrylamide copolymer in the ink-receiving layer was replaced by polyvinyl butyral (weight average molecular weight: 32,000). When this original plate was exposed and printed in the same manner as in Example 1, 8,000 copies of a good printed matter free of stains were obtained.

Example 4 In place of 3 g of methanol silica of Example 1, Glasca 4
A heat-sensitive lithographic printing plate was obtained in the same manner as in Example 1 except that 4.5 g of 01 (manufactured by Nissita Laboratories, a 20% by weight methanol colloid solution composed of ZrO ₂ · SiO ₂ ) was used.
This original plate was exposed in the same manner as in Example 1 and printed with a Harris printing machine. As a result, 10,000 copies of good printed matter free of stains were obtained.

Example 5 2-hydroxyethyl methacrylate / methyl methacrylate (70/30% by weight) was used instead of 1 g of a 10% ethylene glycol monomethyl ether solution of 2-hydroxyethyl methacrylate homopolymer of the hydrophilic layer in Example 1.
Of a 10% ethylene glycol monomethyl ether solution of a copolymer (weight average molecular weight 200,000) consisting of
A heat-sensitive lithographic printing original plate was obtained in the same manner as in Example 1 except that was used. The original plate was exposed in the same manner as in Example 1 and printed with a Komori Sprint printing machine. As a result, 15,000 copies of a good printed product without stain were obtained.

Example 6 2-hydroxyethyl methacrylate / acrylic acid (90/10% by weight) was used instead of 1 g of a 10% solution of 2-hydroxyethyl methacrylate / methyl methacrylate copolymer of Example 5 in ethylene glycol monomethyl ether.
2 g of a 10% ethylene glycol monomethyl ether solution of a copolymer (weight average molecular weight 300,000) consisting of
A heat-sensitive lithographic printing original plate was obtained in the same manner as in Example 1 except that was used. This original plate was exposed in the same manner as in Example 1 and printed with a Komori Sprint printing machine. As a result, 20,000 copies of a good printed matter free of stains were obtained.

Examples 7 to 13 The same aluminum plate as used in Example 1 (material JISA105)
0, a thickness of 0.24 mm), a coating solution for an ink receiving layer having the following composition was applied thereto, and dried at 100 ° C. for 1 minute to obtain an aluminum substrate having an ink receiving layer having a dry coating weight of about 0.6 g / m ^2. Obtained. (Formulation of coating liquid for ink-receiving layer) N- (p-aminosulfonylphenyl) methacrylamide / methyl methacrylate / acrylonitrile / 2-hydroxyethyl methacrylate (40/10/30/20 wt% copolymer) 3 g Dye described in the specification (see Table 1) 0.33 g Ethylene glycol monomethyl ether 50 g Methyl ethyl ketone 47 g

[0076]

[Table 1]

The same hydrophilic layer as in Example 1 was applied to each substrate to obtain a heat-sensitive lithographic printing original plate. These printing original plates were prepared at 600 mJ / c using the same plate setter as in Example 1.
Exposure was at an energy of m ² . Next, when the printing plates were printed using a fountain solution and ink composed of a 10% by volume aqueous solution of isopropyl alcohol containing an etchant using a Komori Sprint printing machine, 10,000 prints of all printing plates were obtained. .

Example 14 On the same aluminum plate as in Example 1, a coating solution for an ink receiving layer having the following composition was applied and dried at 100 ° C. for 1 minute.
An aluminum substrate having an ink receiving layer with a dry coating weight of about 0.6 g / m ² was prepared. (Formulation of coating liquid for ink receiving layer) N- (p-aminosulfonylphenyl) methacrylamide / ethyl methacrylate / acrylonitrile (55.2 / 35.2 / 9.6 wt%) copolymer 3 g Described dye (I-14) 0.75 g gamma-butyrolactone 9.5 g methyl lactate 3 g methyl ethyl ketone 22.5 g propylene glycol monomethyl ether 22 g

Next, the coating solution for the hydrophilic layer prepared as described below was applied on the ink receiving layer using a bar,
After drying for 5 minutes, a hydrophilic layer having a dry coating weight of about 2 g / m ² was provided to obtain a heat-sensitive lithographic printing original plate. (Preparation of coating solution for hydrophilic layer) 18 g of tetraethoxysilane,
A beaker was charged with 32 g of ethanol, 32 g of pure water and 0.02 g of nitric acid, and stirred at room temperature for 1 hour to prepare a sol solution. 3 g of this sol solution, polyvinyl alcohol (trade name P
VA117: 4 g of a 10% aqueous solution of Kuraray Co., Ltd., 8 g of a 20% aqueous solution of colloidal silica (trade name: Snowtex C: manufactured by Nissan Chemical Co., Ltd.), 8 g of pure water, and 0.04 g of polyoxyethylene nonylphenyl ether Mixed.

Next, this printing original plate was exposed using the same plate setter as in Example 1 at an energy of 600 mJ / cm ² . The exposed printing plate was mounted on a Komori Sprint printing machine and printed. As a result, 40,000 copies of good prints free of stains were obtained.

Examples 15 to 18 In place of 4 g of the 10% aqueous solution of polyvinyl alcohol in Example 14, hydrophilic resins were used as shown in Table 2.

[0082]

[Table 2]

In the case of Example 18, since the gelling of the coating solution was rapid, the coating was completed immediately after mixing this copolymer. Except for this, a heat-sensitive printing original plate was prepared in the same manner as in Example 14. These printing original plates were exposed using the same plate setter as in Example 1 at an energy of 600 mJ / cm ² . When the exposed printing plate was printed by a Komori Sprint printing machine, as a result of exposing and printing, 40,000 copies of good printed matter without stain were obtained in any printing plate.

Example 19 On the substrate coated with the ink receiving layer of Example 7, a hydrophilic layer having the following formulation was applied, dried at 100 ° C. for 1 minute, and dried in an amount of about 1 g.
A heat-sensitive printing plate having a three-dimensionally crosslinked hydrophilic layer having a dry coating weight of / m ² was obtained. (Formulation of Coating Solution for Hydrophilic Layer) Poly-2-hydroxyethyl methacrylate (same as in Example 1) 10% by weight solution of ethylene glycol monomethyl ether 1 g methanol silica (Nissan Chemical same as in Example 1) 3 g aminopropyltriethoxysilane 0.05 g methanol 16 g This master plate was prepared by using the same plate setter as in Example 1 for 6 g.
Exposure was performed with an energy of 00 mJ / cm ² , and then printing was performed in the same manner as in Example 1. As a result, 20,000 copies of a good printed product free of stains were obtained.

Example 20 Instead of the aluminum plate of Example 8, a polyethylene terephthalate film having a thickness of 0.2 mm was used. In all other respects, a heat-sensitive lithographic printing plate was obtained in the same manner as in Example 8. This original plate was exposed in the same manner as in Example 8 and attached to a Komori Sprint Printer for printing.
A good printed matter free of stains of 00 parts was obtained.

[0086]

According to the present invention, the disadvantages of the conventional heat mode plate making method using laser exposure can be solved. That is, by using the lithographic printing original plate of the present invention, it is possible to mount the lithographic printing plate directly on a printing press without performing development processing and to perform printing. A lithographic printing plate is obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hidekazu Ohashi 4000F Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. (Reference) 2H025 AA00 AA12 AB03 AC08 AD01 AD03 CC20 DA36 FA03 FA10 2H096 AA07 AA08 BA16 BA20 CA20 EA04 2H114 AA04 AA24 AA27 AA30 BA01 BA10 DA05 DA08 DA14 DA15 DA43 DA44 DA46 DA51 DA52 DA53 DA55 DA56 DA57 DA60 DA64 DA75 DA79 EA01 EA02 EA03

Claims (5)

[Claims] 1. On a support: a) an ink receiving layer containing a photothermal conversion agent, b) beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metals. A heat-sensitive lithographic printing plate precursor comprising a hydrophilic layer formed by applying a solution containing a colloid of an oxide or hydroxide of at least one element selected from the group consisting of: and a hydrophilic resin in this order. 2. The method according to claim 1, wherein the hydrophilic resin has a hydrophilic layer solid content of 0.1 to 0.1.
The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the amount is 30% by weight. 3. The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the hydrophilic resin is a polymer compound having a hydroxy group or a carboxy group. 4. The heat-sensitive lithographic printing plate precursor according to claim 1, wherein the hydrophilic resin is a homopolymer or a copolymer of hydroxyalkyl acrylate or hydroxyalkyl methacrylate. 5. The sol according to claim 1, wherein the colloid is a hydrocondensate of at least one compound selected from di, tri and / or tetraalkoxy silicon, tetraalkoxy aluminum, tetraalkoxy titanium and tetraalkoxy zirconium. Heat-sensitive lithographic printing plate precursor.