JPH04172350A - Preparation method for lithography plate - Google Patents

Abstract

PURPOSE:To obtain a lithography plate free from any problem including contamination during a printing process due to the remaining film of a sensitive layer by transferring only an image section onto a pebbled support substrate. CONSTITUTION:Image exposure and development treatment are applied to an image formation material having a photosensitive layer containing a photosensitive composite on a supporting body with a thermo-softening layer formed between the photosensitive layer and the supporting body. An image is thereby formed and transferred to a support body having only an image section pebbled, thereby forming a lithography plate. By using the aforementioned pebbled support body, a problem such as contamination due to the remaining film of a sensitive layer during a printing process can be eliminated, and a lithography plate can be easily obtained.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for making a lithographic printing plate. The present invention
The present invention provides a lithographic printing plate that uses a grained support substrate (for example, a grained aluminum plate, etc.) and that does not cause stains due to residual film during printing.

[Foreground of the invention]

Conventional photosensitive lithographic printing plates (hereinafter sometimes referred to as rPS plates) generally have a photosensitive layer formed on a grained aluminum plate, and the photosensitive layer is exposed and developed to be exposed to light in an imagewise manner. The remaining photosensitive layer portion is used as an ink-receiving portion and the other portion is used as a non-ink-receiving portion (or vice versa) in a printing plate. The purpose of graining the aluminum plate is to improve adhesion to the photosensitive layer and water retention during printing. However, because a supporting substrate such as a grained aluminum plate is grained, there are fine irregularities on the surface, and the photosensitive composition that forms the photosensitive layer remains in these concave parts, resulting in a residual film. Easy to stain during printing.

Purpose of the Invention 1 The present invention solves the above-mentioned problems of the prior art, and provides a lithographic printing plate using a grained support substrate, which does not have problems such as stains during printing due to residual film of the photosensitive layer, and , it is an object of the present invention to provide a method for preparing a lithographic printing plate that can easily obtain such a lithographic printing plate. Structure and operation of the invention The above object of the present invention is to provide a photosensitive layer containing a photosensitive composition on a support, and a heat softening layer is formed between the photosensitive layer and the support. This is achieved by a method for creating a lithographic printing plate, in which a lithographic printing plate is created by exposing and developing an image-forming material to form an image, and then transferring only the image area onto a grained support substrate. Ta. A lithographic printing plate generally has an ink-receptive photosensitive layer formed on a preferably hydrophilic support, which becomes solubilized by exposure to light. When this photosensitive layer is subjected to imagewise exposure and development, the non-image area is removed while leaving the image area, thereby forming an image. In printing, the difference in properties of image areas being lipophilic and non-image areas being hydrophilic is utilized. However, depending on the case, the hydrophilicity and lipophilicity may be reversed. In the present invention, any support substrate can be used as long as it is grained and can be formed into a printing plate. The material may be selected depending on the specific aspect, and for example, one having physical properties that can be printed on a normal lithographic printing machine may be used as appropriate. Examples of the material for the support base include various non-metallic and metal support bases. Examples of non-metallic supporting substrates that can be used include plastic films such as polyethylene terephthalate, paper, and synthetic paper. Composite materials of these materials and composite materials of these and metal foils can also be used. Specifically, typical nonmetallic supports include nitrocellulose film,
Mention may be made of triacetylcellulose films, polyvinyl acetal films, polystyrene films, polyethylene terephthalate films, polycarbonate films, polyα-olefins such as polyethylene, polypropylene films and other resin films,
Alternatively, a paper support coated on one or both sides with an α-olefin polymer such as polyethylene may be used. In addition, various metal support substrates can be preferably used as the support substrate, such as aluminum plates, zinc plates, iron plates surface-treated with chrome plating, copper-aluminum plates, copper-stainless steel plates, chrome-copper plates, etc. or tri-metal plates such as chromium-copper-aluminum plates, chromium-copper-iron plates, chromium-copper-stainless steel plates, etc., preferably with hydrophilic metal supports, or surfaces treated with the above metals. Suitable are substrates having hydrophilic surfaces, such as coated or film supports, or three-layer plates in which a resin layer is sandwiched between metal plates such as aluminum. Among the above, a grained aluminum plate is particularly preferred as the supporting substrate. The preferably used aluminum plate is preferably subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. These treatments can be performed by known methods. Examples of the graining treatment include a mechanical method and an electrolytic etching method. Examples of the mechanical method include a ball polishing method, a brush polishing method, a polishing method using liquid honing, and a Hough polishing method. Depending on the composition of the aluminum plate, the above methods can be used alone or in combination. Preferred is electrolytic etching. Electrolytic etching is generally performed by immersing an aluminum plate in a bath containing one or more inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid. After the graining process, if necessary, desmutting is performed using an aqueous alkali or acid solution to neutralize the material, followed by washing with water. The anodizing treatment is generally performed by electrolyzing using an aluminum plate as an anode using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. as an electrolytic solution. Formed anodized skin M! is 1-50
■/dbo is preferably appropriate, more preferably 10~
40■/drrr. Here, the amount of anodized film can be determined by immersing an aluminum plate in a phosphoric acid chromic acid solution (produced by dissolving 35% of an 85% phosphoric acid aqueous solution and 20 g of chromium (VI) oxide in 1 part of water). It can be determined by dissolving the film and measuring the change in weight of the plate before and after the film is dissolved. Pore sealing treatments include boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, and the like. In addition, water-soluble polymer compounds,
Subbing treatment can also be performed using an aqueous solution of a metal salt such as fluorinated zirconate. The lithographic printing plate obtained according to the present invention (hereinafter also referred to as "the lithographic printing plate of the present invention") is an image-forming material having a photosensitive layer containing a photosensitive composition on a support, which is image-formed by exposing and developing the image-forming material. It is obtained by processing to form an image and transferring only the image portion to a supporting substrate. The photosensitive layer of the image forming material used in the present invention (hereinafter also referred to as "image forming material of the present invention") may be colored by using a coloring agent or the like, or may not be colored. . Coloring is advantageous in that it makes it easier to understand the transfer status. In the image forming material of the present invention, a heat softening layer is formed between the photosensitive layer and the supporting substrate. Hereinafter, possible specific configurations of the photosensitive layer and the heat softening layer will be described in more detail. Various types of photosensitive compositions can be used as the photosensitive composition contained in the photosensitive layer of the image forming material of the present invention. In other words, when a usable photosensitive composition is irradiated with actinic rays, its molecular structure undergoes a chemical change in a short period of time, and its solubility in a solvent changes. Examples of photosensitive compositions that can be used include the following: Examples of so-called negative-positive type resins in which the solubility of exposed areas decreases include photocrosslinkable photosensitive resin systems represented by polyvinyl alcohol esterified with cinnamic acid; There are also systems in which diazonium salts and their condensates are mixed with polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, etc.; there are also systems in which aromatic azide compounds are used as photocrosslinking agents and mixed with binders such as cyclized rubber.Furthermore, there are photoradical polymerization. Photosensitive resins that utilize photoionic polymerization or photoionic polymerization can also be used. In addition, so-called positive-positive type resins that increase the solubility of exposed areas include, for example, photosensitive resin compositions that use 0-quinonediazide as a photosensitive substance. There are things, specifically,
1.2-penzoquinonediazide 4-sulfonyl chloride, 1,2-naphthoquinonediazide-4-sulfonyl chloride, 1.2-naphthoquinonediazide-5-sulfonyl chloride, 1,2-naphthoquinonediazide-6
A compound obtained by condensing -sulfonyl chloride with a compound containing a hydroxyl group and/or an amino group is preferably used. Examples of the above-mentioned hydroxyl group-containing compounds include trihydroxybenzophenone, dihydroxyanthraquinone, bisphenol A1 phenol novolac resin, resorcin benzaldehyde condensation resin, and pyrogallol acetone condensation resin. In addition, as the above amino group-containing compound,
Examples include aniline, p-aminodiphenylamino, p-aminobenzophenone, 4,4'-diaminodiphenylamine, and 4,4-diaminobenzophenone. Regarding the above 0-quinonediazide compound, J, K
“Light 5intensive 5ys” by OSAR
tell” (Wiley & 5ons, New Yo
rk, 1965) and those described in "Photosensitive Polymers" by Inui Nagamatsu (Kodansha, 1977) can also be used. Further, as positive-positive type compounds, (i) compounds that can generate acids upon irradiation with actinic rays, (11) compounds that have at least one bond that can be decomposed by acids, and (■) two or three different types of phenols. It is also possible to use a photosensitive resin composition containing a novolac resin including the following. The content of the photosensitive composition in the photosensitive layer is preferably 5 to 80% by weight, for example. Further, as the binder constituting the photosensitive layer, a polymer compound is used which is film-forming and solvent-soluble, and preferably dissolves or swells in an alkaline developer. Preferred specific examples of such polymeric compounds include, for example, polymeric compounds having carboxylic acid vinyl ester polymerized units represented by the following general formula in their molecular structure. RCOQC)l=CH2 However, R represents an alkyl group having 1 to 17 carbon atoms. Any polymer compound having the above structure can be used, but as the carboxylic acid vinyl ester monomer for constituting the polymerized unit represented by the above general formula, the following examples are preferable. The name and chemical formula are also shown. ■Vinyl acetate CH3CO0CH= CH2■
Vinyl propionate Bv C1hCHzCOOCH=C
)It■Vinyl butyrate CHz (CHz)tcO
OcH=cHz■Vinyl pivalate (C1(3)
3CCOOCH=CH! ■Vinyl caproate CH3
(C)l4COOCR=CH2■Vinyl caprylate
CH3(CH2)6COOCH=CH2■Vinyl caprate CH:1(C)12)IIcOOc)l=c
H2■ Vinyl laurate CI (3 (CFlz),
,C00C)I =C)Iz■Vinyl myristate
C) I:l (CH2) +□C00CH= CH2[
Phase] Vinyl palmitate CH3 (CH2) +4CO
OCH=CHz■ Vinyl stearate CH3(CHz
) 16cOOctI=CI(2@vinyl versatoxide (R" R2 is an alkyl group, and the sum of its carbon numbers is 7. In other words, it is in the form R' + R2 = Cq H + b) Note that the above R has a substituent In other words, vinyl esters of substituted carboxylic acids are also included in the polymerized unit.The polymer compound may be a polymer obtained by polymerizing one type of carboxylic acid vinyl ester, or a polymer obtained by polymerizing two or more types of carboxylic acid vinyl esters. The polymer unit represented by the above general formula and Monomer units that can be used in combination include, for example, ethylenically unsaturated olefins such as ethylene, propylene, isobutylene, butadiene, isoprene, etc., such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, etc. styrenes, such as acrylic acids such as acrylic acid and methacrylic acid, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride, such as diethyl maleate, dibutyl maleate, di-2-ethylhexyl maleate, Diesters of unsaturated dicarboxylic acids such as dibutyl fumarate and di-2-ethylhexyl fumarate, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate,
α-methylene aliphatic monocarboxylic acid esters such as phenyl acrylate, α-methyl chloroacrylate, methyl methacrylate, and ethyl methacrylate; Nitriles such as acrylonitrile and methacrylonitrile; Amides such as acrylamide; e.g. acrylic Anilides such as anilide, P-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, e.g. evamethyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether,
Vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene, 1°1-dimethoxyethylene, 1,2-dimethoxyethylene, 1.
1-dimethoxycarbonylethylene, 1-methyl-1-
Ethylene derivatives such as ditroethylene, such as N-vinylpyrrole, N-vinylcarbazole,
There are vinyl monomers such as N-vinyl compounds such as N-vinylindole, N-vinylpyrrolone, and N-vinylpyrrolidone. These vinyl monomers generally exist in polymer compounds in a structure in which unsaturated double bonds are cleaved. Particularly preferred polymer compounds for use in the present invention are those having vinyl acetate polymerization units in their molecular structure. Among them, vinyl acetate polymerization units are 40 to 95.
-t%, number average molecular weight (Mn) is 1,00
0 to 100,000, weight average molecular weight (M w)
is preferably 5,000 to 500,000. More preferably, vinyl acetate polymerized units (especially 40
~95-t%) and carboxylic acid vinyl ester polymerized units having a longer chain than vinyl acetate, preferably having 4 to 17 carbon atoms, especially vinyl versatate polymerized units (especially those containing 10 to 50-t%) A polymer compound having a number average molecular weight (M n ) of 10.000 to 15 is preferable.
0,000 is preferred. In this case, the monomer that copolymerizes with vinyl acetate to form a polymer compound having vinyl acetate polymerized units may be any monomer that can form a copolymer, such as among the monomers listed above. You can arbitrarily choose from. Copolymers that can be used as polymeric compounds in the present invention are listed below by indicating their heptamer components. However, it goes without saying that the invention is not limited to the following examples. ■Vinyl acetate-ethylene ■Vinyl-styrene acetate ■Vinyl acetate-crotonic acid ■Hinyl acetate-maleic acid ■Vinyl acetate-2-ethylhexyl acrylate ■Vinyl acetate-2-ethylhexyl maleate ■Vinyl acetate-methyl vinyl ether ■Vinyl acetate-vinyl chloride■ Vinyl acetate-N-vinylpyrrolidone [phase] Vinyl acetate-vinyl propionate ■Vinyl acetate-
Vinyl pivalate @ Vinyl acetate Rubersatate @ Vinyl acetate - Vinyl laurate [Phase] Vinyl acetate - Vinyl stearate [Phase] Vinyl acetate Rubersatate - Ethylene ■ Vinyl acetate Rubersatate - 2- Ethylhexyl acrylate ■ Vinyl acetate Rubersatate - Vinyl Laurate [Co., Ltd.] Vinyl Acetate Rubersatate - Crotonic Acid ■ Vinyl Propionate Rubbersatate [Co., Ltd.] Vinyl Rubersatate [Co., Ltd.] Vinyl Rubersatate - Crotonic acid ■ Pivalic acid - Vinyl stearate - Maleic acid Furthermore, as a polymer compound used as a binder constituting the photosensitive layer, the molecular structure contains a structural unit having an aromatic hydroxyl group represented by the following general formula. Examples include polymeric compounds that General formula: where R" and R" are hydrogen atoms, alkyl groups or carboxylic acid groups, R13 is hydrogen atoms, halogen atoms or alkyl groups, R is hydrogen atoms, alkyl groups, phenyl groups or aralkyl groups, X is nitrogen Represents a divalent organic group that connects an atom and an aromatic carbon atom. n is O or l. Y represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent. Specific examples of monomers forming the structural unit represented by the above general formula include N-(4-hydroxyphenyl)-(meth)acrylamide, N-(2-hydroxyphenyl)-(meth)acrylamide, Monomers of (meth)acrylamides such as N-(4-hydroxynaphthyl)-(meth)acrylamide; o-lm- or p-
Hydroxyphenyl (meth)acrylate monomer; 0
-1m-p-hydroxystyrene monomer and the like can be mentioned. Preferably 0-lm- or p
- hydroxyphenyl (meth)acrylate monomer,
N-(4-hydroxyphenyl)=(meth)acrylamide monomer, more preferably N-(4-hydroxyphenyl')-(meth)acrylamide monomer. When using a polymer compound having a structure having an aromatic hydroxyl group represented by the above general formula as a binder, use a copolymer of a heptamer forming the structure and the heptamer etc. described below. is preferred. Alkyl acrylates: R5 CH2=C? (, -OR' acrylic acids, R3 □ CH2=C C-01 (Here, R5 represents a hydrogen atom, an alkyl group, or a halogen atom, and R6 represents an alkyl group, a phenyl group, or a naphthyl group. The proportion of the group having an aromatic hydroxyl group represented by the above general formula in the polymer is preferably 1 to 30 mol%.The proportion of the units formed from the acrylonitriles in the copolymer is as follows: It is preferably 0 to 50 mol%, and more preferably 5 to 40 mol% in consideration of developability.The proportion of structural units formed from the above-mentioned alkyl acrylates is preferably 50 to 95 mol%. It is suitable from the viewpoint of developability, and furthermore, it is 60~
95 mole % gives the most suitable developability. In addition to the above-mentioned structural units, the cough polymer compound may be copolymerized with the above-mentioned acrylic acids such as acrylic acid or methacrylic acid for the purpose of finely adjusting the developability. Considering the development latitude, the proportion in the compound is preferably 0 to 20 mol%, and 0 to 1O
Mole % is most preferred. The weight average molecular weight of such a polymer compound is preferably from 1,000 to 100,000, more preferably from 1,000 to 100,000, from the viewpoint of developability or resolution when a low alkaline aqueous solution is used as a developer. A range of 30.000 is preferred. These polymer compounds can be synthesized by a well-known copolymerization method. Specific examples of such polymer compounds include copolymers having the following structure. (Weight average molecular weight: 1,000-30,000)1
: m : n = (1-25): (5-40):
(50-95) Here, R17 represents a hydrogen atom or a methyl group. Further, in the present invention, a polycondensation resin such as a novolac resin obtained by polycondensation of at least one type of phenol and an active carbonyl compound may also be used as a binder. These phenols include all compounds in which at least one hydrogen atom bonded to an aromatic ring is substituted with a hydroxyl group, and specifically include phenol, O-cresol, m-cresol, p-cresol, 3 , 5-xylenol, 2.4-xylenol, 2,5-xylenol, carvacrol, thymol, catechol, resorcinol, hydroquinone, pyrogallol, phloroglucin, and an alkyl group (1 to 8 carbon atoms) substituted phenol. Active carbonyl compounds include, for example, aldehydes and ketones, and specific examples include formaldehyde, acetaldehyde, benzaldehyde, acrolein, furfural, and acetone. The above polycondensation resins include phenol formaldehyde novolac resin, m-cresol formaldehyde novolak resin, phenol/m-cresol/formaldehyde copolycondensate resin, phenol/P-cresol/
Formaldehyde copolycondensate resin, m-cresol/p
-Cresol formaldehyde copolycondensate resin, O-
Cresol/p-cresol/formaldehyde copolycondensate resin, phenol/0-cresol/m-cresol/formaldehyde copolycondensate resin, phenol/0
Examples include -cresol/P-cresol/formaldehyde copolycondensate resin, phenol/m-cresol/P-cresol/formaldehyde copolycondensate resin, and the like. A preferred novolac resin is a phenol formaldehyde novolac resin, and the molecular weight is a weight average molecular weight Mw of 3500 to 500 and a number average molecular weight Mn of 1000 to 20.
A range of 0 is preferred. The molecular weights of the polymer compounds herein, including the molecular weights of the resins mentioned above, are measured by gel permeation chromatography (GPC). Number average molecular weight Mn
, l and weight average molecular weight Mw are calculated by smoothing the peaks in the oligomer region (peak (connecting the centers of the peaks and valleys). In addition, in the novolac resin, pyrolysis gas chromatography (PGC) is used as a method for confirming the quantitative ratio of different phenols used in the synthesis thereof. Regarding pyrolysis gas chromatography, its principles, equipment, and experimental conditions can be found, for example, in Journal of the Chemical Society of Japan, New Experimental Lectures by Arata Tsuge, Volume 19, Polymer Chemistry (I) 47
The method for qualitative analysis of novolac resins using pyrolysis gas chromatography is described in pages 4 to 485 (published by Maruzen 1978), etc., and the method for qualitative analysis of novolac resins using pyrolysis gas chromatography is described in "Morio Tsuge, Takashi Tanaka, Masayuki Tanaka"
The method shall be based on the method described in "Analytical Chemistry" Volume 18, pp. 47-52 (1969). Furthermore, other polymeric compounds that can be used as binders include (meth)acrylic acid (co-) Also includes sulfoalkyl esters of polymers, vinyl acecool (co)polymers, vinyl ether (co)polymers, acrylamide (co)polymers, styrene (co)polymers, cellulose derivatives, vinyl acetate (co)polymers, etc. The photosensitive layer of the image forming material of the present invention can contain an appropriate colorant. Generally, when a colorant is used, a dye or a pigment can be used. For example, yellow, Magenta, cyan, and black pigments and dyes, as well as other metal powders, white pigments, and fluorescent pigments may also be used.The following are some of the many pigments and dyes known in the art. (C, I means color index) Victoria Pure Blue (C, I 42595) Auramine (C, I 41000) Cathylone Brilliant Flavin (C, I Basic 13) Roguemi 76 G CP (C, I 45160
) Rhodamine B (C, I 45170)
70 K2O: 100 (C, I 5
0240) Erioglaucine X (C,I 420
80) First Black HB (C, I 26150
) No, 1201') t /-Louis x o -(C
, I 21090) Lionor Yellow G RO (C,
I 21090) Shimla Fast Yellow 8CF (C, I 21105) Benzidine Yellow 4T-564D (C, I 21095) Shimla Fast Red 4015 (C, I 12355) Lionol L,D 7 B12O3 (C, 115830
) First Gen Blue TGR-L (C, r 74160) Lionor Blue SM (C, I 26150)
Mitsubishi Carbon Black M A-100 Mitsubishi Carbon Black 130, 1140.1150 Cyanine Blue 4920 (Dainichiseika) Seiryoku First Carmine 1483 (Dainichiseika) Seika First Yellow H-7055, 2400 (Dainichiseika) Photosensitive When a colorant is contained in the layer, the content of the colorant is preferably, for example, 5% to 50% by weight. When a colorant is used, the colorant/binder ratio in the photosensitive layer can be determined by a method known to those skilled in the art, taking into account the target optical density and the removability of the photosensitive layer to a developer. For example, in the case of dyes, the value is generally preferably from 5% to 75% by weight, and for pigments, the value is generally preferably from 5% to 90% by weight. The thickness of the photosensitive layer can be appropriately selected by a method known to those skilled in the art depending on the target optical density, the type of colorant (dye, pigment, carbon black) used in the photosensitive layer, and its content. However, within the allowable range, the thinner the photosensitive layer is, the higher the resolution and the better the image quality. Therefore, the film thickness is generally in the range of 0.1 μm to 5 μm, which is preferable. In addition to the above-mentioned materials, a plasticizer, a coatability improver, etc. may be added to the photosensitive layer, if necessary. Examples of plasticizers include various low-molecular compounds such as phthalates, triphenyl phosphates, and maleates; examples of coatability improvers include nonionic surfactants such as ethyl cellulose and polyalkylene ethers. surfactants, fluorine-based surfactants, and the like. Alternatively, a colorant layer may be provided separately from the photosensitive layer, and the photosensitive layer may be divided into two layers: a colorant layer made of a colorant and a binder, and a photosensitive layer made of a photosensitive composition and a binder. In this case, it does not matter which layer is present on the support side. The photosensitive layer can generally be formed by dissolving a photosensitive composition, optionally a coloring agent, and an appropriate binder in an appropriate solvent to form a coating solution, and coating this on a support. . In the present invention, the photosensitive layer is preferably formed by applying a coating liquid containing methyl lactate. Although it is preferable to prepare a coating solution using only methyl lactate as a solvent and form a photosensitive layer using this, other solvents can also be used in combination with methyl lactate. However, when other solvents are used in combination, the amount of the solvent used in combination is preferably less than 50 wt% of the solvent used. . In addition to methyl lactate, the following solvents can be used in combination with methyl lactate or without using methyl lactate. That is, for example, cyclohexanone, ethylene dichloride, dichloromethane, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate,
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, N,N-dimethylformamide, dimethyl sulfoxide, N. Solvents such as N-dimethylacetamide, acetylacetone, dioxane, tetrahydrofuran, γ-butyrolactone, propylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, etc. Can be used. The coating method for coating the photosensitive layer on the support is as follows:
For example, roll coating, reverse roll coating, dip coating, air knife coating, gravure coating, gravure offset coating, homper coating, blade coating,
Methods such as ront coating, wire doctor coating, spray coating, curtain coating, and extrusion coating are used. Drying is generally preferably carried out by blowing heated air onto the coated surface. The heating temperature at this time is
The temperature should be lower than the softening temperature of the heat-softening layer and should be appropriately selected according to the type of the heat-softening layer, but - for boat fishing, the temperature is preferably 30°C to 200°C, particularly 40°C to 14°C.
A range of 0°C is preferred. During drying, the photosensitive layer is generally dried while keeping the temperature of the heated air constant, but it is also possible to dry the photosensitive layer by increasing the temperature of the heated air in stages. . The heated air is preferably supplied to the coated surface at a rate of 0.1 m/sec to 3°m7 seconds, and particularly preferably at a rate of 0.5 m/sec to 20 m/sec. It is. When the photosensitive layer contains a photopolymerizable substance, an overcoat layer that can dissolve or swell in the developer may be provided on the photosensitive layer in order to prevent polymerization inhibition caused by the influence of oxygen. can. Resins used for the overcoat layer include polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinyl methyl ether,
Polyvinylpyrrolidone, polyamide, gum arabic, glue, gelatin, casein, celluloses (e.g., viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, etc.), starches (e.g., soluble starch, modified starch, etc.) etc. can be mentioned. ' The image forming material of the present invention can obtain an image by developing it after image exposure. Image exposure can be carried out, for example, by bringing the color separation mesh film and the image forming material into close contact with each other and irradiating them with, for example, ultraviolet rays. As the light source, any one such as a mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a tungsten lamp, a xenon lamp, a fluorescent lamp, etc. can be used. Development subsequent to image exposure can be performed, for example, as follows. That is, as a developing solution for forming an image, an alkaline developing solution containing water as a main solvent is preferably used, and examples of alkaline agents used in the developing solution include sodium carbonate, sodium hydrogen carbonate, sodium silicate,
Potassium silicate, sodium hydroxide, potassium hydroxide,
Lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate, dibasic potassium phosphate,
Inorganic alkaline agents such as tertiary ammonium phosphate, ammonium diphosphate, sodium metasilicate, sodium bicarbonate, potassium carbonate, ammonium carbonate, ammonium silicate, or mono-, di-, or triethanolamine, or tetraalkylammonium hydroxide. An organic alkaline agent such as The content of the alkaline agent in the developer composition is generally preferably used in the range of 0.05 to 30% by weight, and the alkaline developer contains ethylene glycol monophenyl ether, benzyl alcohol, n-propyl Organic solvents such as alcohol, surfactants, sulfites, chelating agents such as EDTA,
It may also contain an antifoaming agent such as an organic silane compound. In the image forming material of the present invention, after an image is formed, only the image area is transferred to a supporting substrate such as a grained aluminum plate. The image forming material of the present invention has a heat softening layer between the photosensitive layer and the support. The thermally softened layer is a supporting substrate (for example, a grained aluminum plate) on which the formed image area is grained.
When thermally transferred onto a supporting substrate having an uneven portion such as a grain, it is softened by heating, and this plays a role in ensuring good image transfer even on an uneven portion such as a grain. The heat-softening layer can be preferably composed of, for example, a polypropylene film, a polyethylene film, etc., particularly an ethylene-vinyl acetate copolymer. Since these materials themselves exhibit good mold release properties, they can also serve as a mold release layer. In a preferred embodiment, a polypropylene layer, a polyethylene layer, or an ethylene-vinyl acetate copolymer layer, which is thinner than the thickness of the support, is provided to form a heat-softening layer. A preferred embodiment is that an ethylene-vinyl acetate copolymer resin layer is provided on the surface of the support, but in this case, the thickness of the ethylene-vinyl acetate copolymer resin layer is sufficient to cover the support surface. There is no particular limitation as long as the thickness is the minimum, but it is preferably thinner than the thickness of the support. As the ethylene-vinyl acetate copolymer resin that can be used, it is preferable that the ratio of vinyl acetate in the copolymer resin is in the range of 5% to 33% by weight, and the V I CAT softening of the resin Preferably, the point is below 80°C. In addition, various polymers, supercooling substances, surfactants, mold release layers, etc. are added to the ethylene-vinyl acetate copolymer resin layer of the present invention within a range where the softening point does not substantially exceed 80°C. be able to. The method of providing an ethylene-vinyl acetate copolymer resin layer on a support is as follows: (1) A solution of an ethylene-vinyl acetate copolymer resin dissolved in an organic solvent such as toluene is coated on the support and then dried. , a method of providing an ethylene-vinyl acetate copolymer resin layer. (2) A solution of polyvinyl acetate, polyvinyl chloride, epoxo resin, polyurethane resin, natural rubber, synthetic rubber, etc. dissolved in an organic solvent is used as an adhesive, and after applying these adhesives on the support, hot air Or the so-called dry lamination method, in which ethylene-vinyl acetate copolymer resin films are dried by heating and then laminated by pressing and bonding under heat. (3) A mixture of ethylene and vinyl acetate, a copolymer of ethylene and acrylic ester, polyamide resin, petroleum resin, rosin, and wax is used as an adhesive, and while heating these adhesives and keeping them in a molten state, Immediately after coating the support by a doctor blade method, roll coating method, gravure method, reverse roll method, etc., an ethylene-vinyl acetate copolymer resin film is laminated, heated to a high temperature as necessary, and then cooled. This is the so-called hot melt lamination method. (4) A so-called extrusion lamination method, in which the ethylene-vinyl acetate copolymer resin is kept in a molten state, extruded into a film using an extruder, and while this is in the molten state, a support is pressed and laminated. (5) When molding a film to serve as a support by melt extrusion, multiple extruders are used to mold ethylene-vinyl acetate copolymer resin in a molten state two times to form an ethylene-vinyl acetate copolymer resin onto the support film. Examples include a so-called coextrusion method for forming a vinyl acetate copolymer resin layer. As mentioned above, the heat-softening layer can also serve as a release layer, but in order to more efficiently transfer the image onto the support substrate and to make it easier to peel off the support after image transfer, it is necessary to In order to provide good releasability between the photosensitive layer and the image, a release layer (including one whose surface has been subjected to release treatment) is provided between the heat-softening layer on the support side and the photosensitive layer. is more preferable. The release layer is made of, for example, silicone resin, fluororesin, polyethylene, polypropylene ethylene-α-olefin copolymer, propylene-α-olefin copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer. It can be formed from a polyamide resin such as a polymer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, ionomer resin, wax, nylon, or copolymerized nylon. Furthermore, silicone resin or fluororesin may be added to melamine resin or polyacrylate urethane resin. The support constituting the image forming material of the present invention is preferably a transparent support. For example, a polyester film, particularly a biaxially oriented polyethylene terephthalate film, is suitable for use in water,
It is preferable in terms of dimensional stability against heat. In addition, acetate film, polyvinyl chloride film, polystyrene film, polypropylene film, and polyethylene film may also be used.

【Example】

Examples of the present invention and comparative examples will be described below. It should be noted that, as a matter of course, the present invention is not limited only to the embodiments described below, but can take various forms. Example 1 In this example, an image forming material was first formed as follows. That is, a 75 μm thick polyethylene terephthalate film was used as a support, and a 25 μm thick ethylene-vinyl acetate copolymer resin layer (Mitsui-vinyl acetate) was placed on this support.
EVAFLEX P-14 manufactured by DuPont Polychemical Company
05, vinyl acetate content 14% by weight, VICAT softening point 68°C) was formed by an extrusion lamination method to form a heat softening layer. A photosensitive layer dispersion having the following composition (colored in this example) was applied onto the surface of the ethylene-vinyl acetate copolymer resin layer of this support using a wire bar until the dry film thickness was 1.
．． It was applied to a thickness of 5 μm and dried at 80° C. for 5 minutes to form a photosensitive layer, thereby producing an image forming material. Photosensitive layer dispersion: p-cresol novolac resin and naphthoquinone-1,2
- Esterified product with diazide-4-sulfonic acid chloride 0.616 g Vinyl acetate-vinyl versatate copolymer (80:
20wt%1 weight average molecular weight 50.000.50% methanol solution) 8.768g carbon black MA-10
0 (manufactured by Mitsubishi Kasei) 0.99 g Methyl lactate 35.2 g Fluorine surfactant analysis (manufactured by 3M Company, FC-430) 0.01 g or more Overlap the films, 4
20 from a distance of 50C1l with a kW metal halide lamp
Image exposure was carried out for a second, and further development was carried out by immersion in the following developer at 32° C. for 30 seconds to form a colored image. Developer solution> Konica PS version developer 5DR-1 (manufactured by Konica) 40ml! Perenx NBL (manufactured by Kao Atlas Co., Ltd.) 100Id
Moru Shui 400I11 Next, a grained aluminum support substrate was prepared by the following method. After degreasing an aluminum plate with a thickness of 0.24 mm in a 5% aqueous sodium hydroxide solution, it was degreased in a 0.3 molar nitric acid aqueous solution at a temperature of 30°C, a current density of 50 A/d, and a treatment time of 3.
Electrolytic etching treatment was performed under conditions of 0 seconds. Next, a desmut treatment was performed with a 5% aqueous sodium hydroxide solution, and then an anodization treatment was performed in a sulfuric acid solution. When the amount of anodic oxide film was measured, it was 20 .mu./dffr. Next, it was immersed in a hot aqueous solution at 90°C for pore sealing treatment. The image surface of the previously obtained colored image was brought into close contact with the grained surface of the grained aluminum support substrate obtained as described above, and then passed between a pair of nip rolls heated to 1.80°C for 5 minutes.
After passing at a speed of 50 cm/min under a pressurized condition of kg/d, the polyethylene terephthalate film (support on the image side) was peeled off. Only the colored image portion was successfully transferred to the grained surface, and a good lithographic printing plate for offset printing was produced. When ordinary offset printing was performed using this lithographic printing plate under the printing conditions shown below, 50,000 sheets of good printed matter could be obtained. Good printed matter was obtained without staining due to residual film as seen in conventional PS plates. (Printing conditions) Printing machine: Heidel GTOZ52 (manufactured by Heidelberg) Ink: Toyo TK-Mark V, red (manufactured by Toyo Ink) Dampening water Nidoho Cool liquid 4 times diluted (IPA 12.5%)
Contains) Paper: Special art 4 large format 73kg (manufactured by Kanzaki Paper) Blanket: Palcan Reflex SW printing speed = 8
000 revolutions/hour Temperature and humidity: 23°C, 60% Example 2 A 30 μm thick ethylene-vinyl acetate copolymer resin layer (
Mitsui-DuPont Polychemical Co., Ltd. EVAFLEX P
-1907, vinyl acetate content 19% by weight, VICAT
A support having a heat-softening layer is formed by extrusion lamination (softening point: 59°C), and a photosensitive layer dispersion having the following composition (in this example, colored) using a wire bar,
After coating to a dry film thickness of 1.5 μm, it was dried at 80° C. for 5 minutes to form a photosensitive layer. (Photosensitive layer dispersion composition) Alkali-soluble polymer composition with the following composition (weight average molecular weight 17,000.50% methyl lactate solution) 2 g (f!: m: n=10:10:80) Pentaerythritol tetraacrylate 4 .3g Michler's Ketone 0.04g Hensiphenone 0.25g Paramethoxyphenol 0.01g Methyl lactate
94g Fluorine surfactant (manufactured by 3M Company, FC-430) O, 01g Carbon black MA-100 (manufactured by Mitsubishi Kasei) 1.98g The alkali-soluble polymer composition was synthesized by the following method. 11 In the fourth flask, 8.85 g of hydroxyphenylmethacrylamide, 2.65 g of acrylonitrile,
Weighed 33.11 g of methyl acrylate and 1.64 g of abbisisobutyronitrile (polymerization initiator),
Using 00g of ethyl alcohol as a solvent, the reaction was carried out at 77°C for 6 hours. Thereafter, 75 g of methyl lactate was added to stop the reaction, and ethyl alcohol was distilled off at 60° C. for 3 hours. As a result, about 95 g of the polymer composition was obtained as a 50% methyl lactate solution. Next, an overcoat layer solution having the composition shown below was coated onto the photosensitive layer using a wire bar so as to have a dry film thickness of 0.3 μm, and dried to prepare an image forming material. (Overcoat layer solution composition) Polyvinyl alcohol (GL-05 manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) 6 g Distilled water
97g methanol
A color separation net negative film was superimposed on the overcoat layer surface of the image forming material obtained with 3g or more, image exposure was performed for 20 seconds from a distance of 50C11 with a 4kW metal halide lamp, and development was performed by immersing it in the following developer for 30 seconds. and formed an image. Developer solution> Sodium carbonate 15g Surfactant (Perex NBL manufactured by Kao Atlas Co., Ltd.) 50g Distilled water
Next, the above image was transferred in the same manner as in Example 1 onto a grained aluminum support substrate prepared in the same manner as in Example 1 to prepare a lithographic printing plate. When off-cent printing was performed in the same manner as in Example I, 50,000 sheets of good printed matter were obtained. Comparative Example 1 A release layer solution having the following composition was applied onto a polyethylene terephthalate film having a thickness of 75 μm using a wire bar so that the dry film thickness was 0.5 μm, and then dried. Release layer solution: Alcohol-soluble nylon CM-8000 (manufactured by Toshi) 7.2 g polyhydroxystyrene. Resin M (manufactured by Maruzen Sekiyu) 1.8 g Methanol 400 g Methyl cellosolve 100 g Next, a photosensitive layer dispersion having the following composition was applied onto the release layer using a wire bar so that the dry film thickness was 1.5 μm. Thereafter, it was dried at 80''C for 5 minutes to prepare a colored image forming material. Photosensitive layer dispersion: 2.3.4-Trihydroxybenzophenone-naphthoquinone-1°2-diazide-4-sulfonic acid ester 0.616 g Phenol formaldehyde novolac resin (M w =960. M n =496)
4.384 g Ethyl cellosolve 39.6 g Carbon black MA-100 (manufactured by Mitsubishi Kasei) 0.99 g The image forming material obtained above was exposed and developed in the same manner as in Example 1 to form an image. The image was transferred onto a textured aluminum support prepared in the same manner as in Example 1, but the transfer was not successful and the image partially remained on the polyethylene terephthalate film side. A good lithographic printing plate could not be obtained.

【Effect of the invention】

As described above, according to the present invention, it is possible to obtain a lithographic printing plate that uses a support substrate with a grain size and is free from problems such as staining during printing due to residual film of the photosensitive layer.

Claims (1)

[Claims] [Claim 1] An image forming material having a photosensitive layer containing a photosensitive composition on a support, and a heat-softening layer formed between the photosensitive layer and the support, is subjected to imagewise exposure and A method for producing a lithographic printing plate, in which a lithographic printing plate is produced by developing an image, and transferring only the image portion onto a grained support substrate.