JPH08314133A - Photosensitive planographic printing plate and its production - Google Patents

Abstract

PURPOSE: To provide a photosensitive planographic printing plate which has an excellent high contrast characteristic, a wide range of adequate development conditions and sufficient plate wear without deterioration of film strength and has high sensitivity and a process for producing this photosensitive planographic printing plate. CONSTITUTION: This photosensitive planographic printing plate is formed by providing a base with a photosensitive layer contg. a surfactant having a conon. distribution in which the concn. of the surfactant is high on the front surface side of the photosensitive layer and is low on the side near the base. In addition, the concn. of the surfactant on the side near the base is below 2/3 the average conon. of the surfactant in the photosensitive layer. The photosensitive layer described above contains an o-quinonediazide compd. and the surfactant.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION A photosensitive lithographic printing plate is one in which a photosensitive layer is provided on a hydrophilic support. For example, in a positive type photosensitive lithographic printing plate, an actinic ray such as ultraviolet rays is provided on the hydrophilic support. An ink-receptive photosensitive layer that is solubilized by exposure to is formed.

In such a positive-working photosensitive lithographic printing plate, when the photosensitive layer is imagewise exposed and then developed, the ink-receptive photosensitive layer in the exposed area is removed to expose the surface of the hydrophilic support. On the other hand, the unexposed portion of the photosensitive layer which is ink-receptive remains on the support to form an ink-receptive layer. In lithographic printing, the difference in the property that the exposed portion is hydrophilic and the unexposed portion is lipophilic is used.

Usually, an o-quinonediazide compound is used as a photosensitive component in the photosensitive layer of a positive type photosensitive lithographic printing plate.

The orthoquinonediazide compound produces a carboxylic acid upon irradiation with an actinic ray and becomes soluble in an alkaline aqueous solution. Therefore, utilizing this property, a positive composition using a photosensitive composition containing these naphthoquinonediazide compounds as a photosensitive component is used. An aqueous alkaline developer is used in the plate-making process of the photosensitive type lithographic printing plate.

These positive-working photosensitive lithographic printing plates are required to have high-sensitivity photosensitivity. Conventionally, in order to increase the contrast of a photosensitive lithographic printing plate, a method of adding a surfactant such as an ether of polyoxyethylene and a higher alcohol, for example, polyoxyethylene lauryl ether to the photosensitive layer has been used. There is. However, when these surfactants are added to the photosensitive layer, the photosensitive lithographic printing plate can be made to have a high contrast, but when a surfactant sufficient to increase the contrast is used, the sensitivity is deteriorated and the developability is adversely affected. Will be given.

As a solution to these problems, JP-A-5-264397 discloses that a first organic coating layer containing an o-quinonediazide compound and a second organic coating layer containing a surfactant are sequentially provided. The technology is disclosed. However, in this technique, it is not possible to expect an increase in sensitivity, and since it is essential to form the first organic coating layer and the second organic coating layer, the production process becomes complicated and the production cost is not increased. I cannot escape.

Therefore, as a result of investigations by the present inventors, it has been found that the above problems can be solved by setting the concentration distribution of the surfactant in the photosensitive layer to a specific concentration distribution.

[0009]

SUMMARY OF THE INVENTION Accordingly, the object of the present invention is to provide excellent hardness, a wide range of suitable developing conditions, sufficient printing durability without deterioration of film strength, and high sensitivity of photosensitivity. It is to provide a planographic printing plate and a method for producing the photosensitive planographic printing plate.

[0010]

The above objects of the present invention are as follows: (1) In a photosensitive lithographic printing plate comprising a support and at least one photosensitive layer containing an o-quinonediazide compound and a surfactant, the surface activity of the photosensitive layer is The concentration of the agent is high on the surface side and low on the side close to the support, and the concentration of the surfactant on the side close to the support is A photosensitive lithographic printing plate characterized in that the average concentration of the surfactant is ⅔ or less. (2) In a photosensitive lithographic printing plate in which at least one photosensitive layer containing an o-quinonediazide compound and a surfactant is provided on a support, the surfactant in the photosensitive layer is
A step tablet for sensitivity measurement (21 steps with a density difference of 0.15) is closely attached to the photosensitive lithographic printing plate, and the plate is exposed and developed so that the 3.0 step of the step tablet is completely clear. A photosensitive lithographic printing plate having a density distribution in which a contact angle is 90 degrees or more in a solid step and 40 degrees or less in a range of 4.0 to 3.0 steps. (3) The photosensitive lithographic printing plate as described in (1) or (2) above, wherein the number of the photosensitive layers containing the o-quinonediazide compound and the surfactant provided on the support is one. (4) A support is dissolved in a photosensitive composition containing an o-quinonediazide compound and a surfactant in a mixed solvent of a good solvent having a low boiling point and a poor solvent having a high boiling point. The method for producing a photosensitive lithographic printing plate as described in (1) to (3) above, wherein the coating solution is applied and dried under at least two different temperature conditions. (5) The method for producing a photosensitive lithographic printing plate as described in (4) above, wherein drying is performed at a low temperature in the initial stage, and then drying is performed at a high temperature. (6) Dissolving a photosensitive composition containing an o-quinonediazide compound and a surfactant on a support in a mixed solvent of a good solvent having a low boiling point surfactant and a poor solvent having a high boiling point surfactant. The method for producing a photosensitive lithographic printing plate as described in (1) to (3) above, wherein the coating solution is applied, then dried at a low temperature in the initial stage, and then dried at a high temperature. . Can be achieved by

First, the support used for forming the photosensitive lithographic printing plate of the present invention will be described.

The support preferably has flexibility so that it can be set in an ordinary printing machine and can withstand a load applied during printing. For example, a metal plate of aluminum, magnesium, zinc, chromium, iron, copper, nickel, etc., An alloy plate of these metals, or a metal plate coated with chromium, zinc, copper, nickel, aluminum, iron or the like by plating or vapor deposition can be used. Of these, the support is preferably one using aluminum or its alloy.

Various aluminum alloys can be used, for example, silicon, copper, manganese, magnesium,
Examples include alloys of metals such as chromium, zinc, lead, bismuth, and nickel with aluminum.

The support made of aluminum or its alloy or the like is usually subjected to a degreasing treatment prior to the graining treatment in order to remove oil and fat components such as rolling oil adhering to the surface of the support. As the degreasing treatment, degreasing treatment using a solvent such as trichlene and thinner, emulsion degreasing treatment using an emulsion of kesilon and triethanol, and the like are used. In addition, an alkaline aqueous solution such as caustic soda can be used for the degreasing treatment. When an alkaline aqueous solution such as caustic soda is used for the degreasing treatment, it is possible to remove stains and oxide films which cannot be removed only by the above degreasing treatment.

The graining treatment of the present invention is a so-called mechanical surface-roughening method of mechanically roughening the surface, a so-called chemical surface-roughening method of chemically selectively surface-melting and roughening the surface, and electrochemical. The surface can be roughened by a known method such as a so-called electrochemical roughening method.

Mechanical surface roughening methods include, for example, ball polishing, brush polishing, blast polishing, buff polishing, and the like, and electrochemical surface roughening methods include hydrochloric acid, nitric acid, etc. There is a method of electrolytically treating with an alternating current or a direct current in an electrolytic solution containing the same.

The graining treatment of the present invention can be carried out by any one of these methods or by using two or more methods in combination.

Since smut is formed on the surface of the support obtained by the graining treatment, it is generally preferable to appropriately perform washing with water or alkali etching in order to remove the smut. Examples of such a treatment include a treatment method such as an alkali etching method described in JP-B-48-28123 and a sulfuric acid desmutting method described in JP-A-53-12739.

The support treated as described above is then anodized. Wear resistance due to anodizing treatment,
The chemical resistance and water retention can be improved. A known method can be used for the anodizing treatment. For example, a method of electrolyzing at a current density of 1 to 10 A / dm ² using an aqueous solution containing sulfuric acid and / or phosphoric acid or the like at a concentration of 10 to 50% is used. Although preferably used, a method of electrolyzing at a high current density in sulfuric acid described in other U.S. Pat.No. 1,412,768, or a method of electrolyzing using phosphoric acid described in U.S. Pat.No. 3,511,661. Etc. can also be used.

The anodized support may be subjected to a pore-sealing treatment if necessary. These sealing treatments can be carried out by using known methods such as hot water treatment, boiling water treatment, steam treatment, sodium silicate treatment, dichromate aqueous solution treatment, nitrite treatment and ammonium acetate treatment.

The support is preferably provided with a hydrophilic layer. For the formation of the hydrophilic layer, a water-soluble polymer, an alkali metal silicate described in US Pat. No. 3,181,461,
Amino acids and salts thereof described in JP-A-60-149491 and JP-A-63-165183, amines having a hydroxyl group and salts thereof described in JP-A-60-232998, JP-A-62- 1
Although it is possible to use a phosphate described in 9494, a polymer compound containing a monomer unit having a sulfo group described in JP-A-59-101651, etc., the following compounds are used in the present invention. Is preferred.

Water-Soluble Polymers Specific examples thereof include vinyl resins such as PVA (polyvinyl alcohol), modified PVA, PVAP (polyvinylphosphonic acid), polyvinylpyrrolidone, and polyvinylimidazoline, and derivatives thereof; polyacrylic acid, polyacrylamide, poly Acrylic acid-based copolymers such as hydroxyethyl acrylate; polyethyleneimine; maleic acid copolymers; polyethylene glycol; polypropylene glycol; polyurethane resin; polyhydroxymethylurea;
Polyhydroxymethyl melamine resin; soluble starch;
CMC (carboxymethyl cellulose); hydroxyethyl cellulose; guar gum; tragacanth gum; xanthan gum; sodium alginate; gelatin and the like. At least one amino group and two or more

[0023]

Embedded image A compound having a group selected from

Examples of the compound having a phosphonic acid group or a salt thereof include 1-aminoethane-1,1-diphosphonic acid and 1-amino-1-phenylmethane-1,1.
-Diphosphonic acid, 1-dimethylaminoethane-1,1-
Diphosphonic acid, 1-dimethylaminobutane-1,1-diphosphonic acid, 1-dimethylaminomethane-1,1-diphosphonic acid, 1-propylaminoethane-1,1-diphosphonic acid, 1-butylaminomethane-1, 1-Diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediaminopentamethylenephosphonic acid, ethylenediaminotetramethylenephosphonic acid, diethylenetriaminopentamethylenephosphonic acid, aminotri (2-propylene-2-phosphonic acid) and hydrochlorides of these compounds , Formates, oxalates and the like, as the compound having a phosphinic acid group or a salt thereof, a compound in which the phosphonic acid group of the compound having a phosphonic acid group is changed to a phosphinic acid group or a salt of these compounds, Examples include aminotrimethylene phosphinic acid and the like. Examples of the compound or a salt thereof having a phosphate group, a salt of the compound phosphonic acid group was changed to phosphate groups of the compound having a phosphonic acid group or their compounds, for example, aminotrimethylene phosphoric acid and the like.

A compound having at least one amino group and a carboxyl group or a sulfone group or a salt thereof. Specific examples thereof include aminoacetic acid, lysine, threonine, serine, aspartic acid, parahydroxyphenylglycine, dihydroxyethylglycine, anthranilic acid. Amino acids such as tryptophan and arginine, aliphatic aminosulfonic acids such as sulfamic acid and cyclohexylsulfamic acid, and hydrochlorides, formates and oxalates of these compounds.

Compounds having at least one amino group and at least one hydroxyl group or salts thereof: Specific examples thereof include monoethanolamine, diethanolamine, trimethanolamine, tripropanolamine, triethanolamine and hydrochlorides of these compounds. , Formate, oxalate and the like.

Alkanes having at least two amino groups or salts thereof Alkanes include straight-chain, branched and cyclic alkanes.

Particularly preferred is NH _2- (CH ₂ ) _n
Is -NH ₂ (n is an integer of 2 to 10).

As a specific example, ethylenediamine, 1,
3-diaminopropane, 1,4-diaminobutane, 1,
2-diaminopropane, 1,2-diamino-2-methylpropane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,2-diaminocyclohexane, 1,8-diaminooctane , 1,
Examples include 9-diaminononane, 1,10-diaminodecane and their compounds such as hydrochlorides, formates and oxalates.

Next, the o-quinonediazide compound and the surfactant used in the photosensitive layer of the photosensitive lithographic printing plate of the present invention will be described.

The o-quinonediazide compound used in the photosensitive layer of the present invention is a compound having an o-quinonediazide group in the molecule and can be used in the present invention.
The quinonediazide compound is not particularly limited, and examples thereof include polycondensation resins having an orthoquinonediazide group, such as ester compounds of polycondensation resins of o-naphthoquinonediazide sulfonic acid and phenols and aldehydes or ketones. To be

Examples of the phenols in the polycondensation resin with the above-mentioned phenols and aldehydes or ketones include phenol, o-cresol, m-cresol,
Examples include monohydric phenols such as p-cresol, 3,5-xylenol, carvacrol, thymol, dihydric phenols such as catechol, resorcin, and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Examples of the aldehyde include formaldehyde,
Examples thereof include benzaldehyde, acetaldehyde, crotonaldehyde, furfural and the like. Of these, preferred are formaldehyde and benzaldehyde. Examples of ketones include acetone and methyl ethyl ketone.

Specific examples of polycondensation resins with phenols and aldehydes or ketones include phenol-formaldehyde resin, m-cresol-formaldehyde resin, m- and p-mixed cresol-formaldehyde resin, resorcin-benzaldehyde resin, Examples include pyrogallol / acetone resin.

In the o-naphthoquinonediazide compound, the condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the OH groups of phenols (reaction rate with respect to one OH group) is preferably 15% to 80%, more preferably 20%. ~
45%.

Further, as the o-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be mentioned. That is, for example, 1, 2,
-Benzoquinone diazide sulfonate, 1,2-
Known 1,2-naphthoquinone diazide sulfonic acid ester, 1,2-benzoquinone diazide sulfonic acid amide, 1,2-naphthoquinone diazide sulfonic acid amide, etc.
Quinone diazide compounds, and more specifically, J. Kosar, "Light-Sensitive Systems," pages 339-352 (1965).
Year), John Wille and Sons
y & Sons (New York), W. S. De Forest (WSDe Forest) "Photoresist", Volume 50 (1975), McGraw Hill (New York). 1,2-benzoquinonediazide-4-sulfonic acid phenyl ester, 1,2,1 ', 2'-di- (benzoquinonediazide-4-sulfonyl) -dihydroxybiphenyl, 1,2-benzoquinonediazide-4- (N- Ethyl-N-β-naphthyl) -sulfonamide, 1,2-naphthoquinonediazide-5-sulfonic acid cyclohexyl ester, 1- (1,2-naphthoquinonediazide-5-sulfonyl) -3,5-dimethylpyrazole, 1, 2-naphthoquinonediazide-5-sulfonic acid-4'-hydroxydiphenyl-4'-azo-β-naphthol Tel,
N, N-di- (1,2-naphthoquinonediazide-5-sulfonyl) -aniline, 2 '-(1,2-naphthoquinonediazide-5-sulfonyloxy) -1-hydroxy-
Anthraquinone, 1,2-naphthoquinonediazide-5
Sulfonic acid-2,4-dihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 2 mol and 4 , 4'-Diaminobenzophenone condensate with 1 mol, 1,2-naphthoquinonediazide-5-sulfonic acid chloride 2 mol and 4,4'-dihydroxy-
A condensation product with 1 mol of 1,1′-diphenylsulfonic acid,
1,2-naphthoquinonediazide-5-sulfonic acid chloride 1 mol condensate with purpurogallin 1 mol, 1,2-
A 1,2-quinonediazide compound such as naphthoquinonediazide-5- (N-dihydroabietyl) -sulfonamide can be exemplified. In addition, Japanese Patent Publication 37-1953
No. 37, No. 37-3627, No. 37-13109, No. 40-26126, No. 40-
No. 3801, No. 45-5604, No. 45-27345, No. 51-13013,
The 1,2-quinonediazide compounds described in JP-A-48-96575, JP-A-48-63802 and JP-A-48-63803 can also be mentioned.

Of the above o-quinonediazide compounds,
An o-quinone diazide ester compound obtained by reacting 1,2-benzoquinone diazide sulfonyl chloride or 1,2-naphthoquinone diazide sulfonyl chloride with pyrogallol-acetone condensation resin or 2,3,4-trihydroxybenzophenone is particularly preferable.

The proportion of the o-quinonediazide compound in the photosensitive layer is preferably 5 to 60% by weight, and particularly preferably 10 to 50% by weight.

Next, the surfactant will be described.

The surfactant that can be used in the present invention is not particularly limited, and is a surfactant that has been conventionally used in the photosensitive layer, such as an amphoteric surfactant, an anionic surfactant and a cationic interface. Activators, nonionic surfactants, fluorine-based surfactants and the like can be used.

Examples of the amphoteric surfactant that can be used include lauryl dimethylamine oxide, lauryl carboxymethyl hydroxyethyl, imidazolinium betaine and the like.

As the anionic surfactant, a fatty acid salt,
Alkyl sulfate ester salt, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfosuccinate, alkyl diphenyl ether disulfonate, alkyl phosphate, polyoxyethylene alkyl sulfate ester salt, polyoxyethylene alkyl allyl sulfate ester salt, naphthalene sulfone Examples thereof include acid formalin condensates and polyoxyethylene alkyl phosphates.

Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, alkylbetaines and the like.

As the nonionic surfactant, polyoxyethylene alkyl allyl ether, polyoxyethylene derivative, oxyethylene / oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid. Examples thereof include esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines and alkylalkanolamides.

Examples of the fluorinated surfactant include copolymers of acrylates or methacrylates containing a fluoroaliphatic group and (polyoxyalkylene) acrylates or (polyoxyalkylene) methacrylates.

In the photosensitive lithographic printing plate of the present invention, at least one photosensitive layer (hereinafter referred to as the photosensitive layer of the present invention) has a high surfactant concentration on the surface side, and
It has a concentration distribution that is low on the support side, and the concentration of the surfactant on the side close to the support is 2/3 or less of the average concentration of the surfactant in the photosensitive layer. .

The concentration of the surfactant in the photosensitive layer of the present invention was adjusted so that a step tablet for sensitivity measurement (21 steps with a density difference of 0.15) was brought into close contact with the photosensitive lithographic printing plate, and 3.0 steps of the step tablet were completely removed. When exposed, developed and plate-made so as to be clear, the contact angle of the printing plate surface is 90 degrees or more in a solid step and 40 degrees or less in a range of 4.0 to 3.0 steps.

The contact angle is CA-D (Kyowa Kagaku Co., Ltd.) using a distilled water at a temperature of 20 ° C. and a humidity of 60% RH.
(Manufactured). As the developer, a developer having the following composition containing no surfactant is used.

<Developer composition> A Potassium silicate (Nippon Kagaku) 120 g Potassium hydroxide (50% aqueous solution) 30 g Pure water 500 g Surfactant is contained in the photosensitive layer in an amount of 0.01 to 10% by weight as a whole. Preferably.

It is preferable to add an alkali-soluble resin to the photosensitive layer of the present invention.

The alkali-soluble resin that can be used in the photosensitive layer is not particularly limited, and examples thereof include novolak resins, vinyl polymers having a phenolic hydroxyl group, and those described in JP-A-55-57841. Examples thereof include condensation resins of polyphenols with aldehydes or ketones.

Examples of the novolac resin that can be used in the present invention include phenol / formaldehyde resin, cresol / formaldehyde resin, JP-A-55-5.
Phenol / cresol / formaldehyde copolymer resin as described in Japanese Patent No. 7841, JP-A-55-12755
Examples thereof include copolymer resins of p-substituted phenol and phenol or cresol and formaldehyde as described in JP-A-3.

The novolak resin preferably has a number average molecular weight Mn of 3.00 × 10 ^{2 to} 7.5 (polystyrene standard).
0 × 10 ³ , weight average molecular weight Mw of 1.00 × 10 ^{3 to} 3.00 × 10 ⁴ ,
More preferably, Mn is 5.00 × 10 ^{2 to} 4.00 × 10 ³ , and Mw is 3.
It is 00 × 10 ^{3 to} 2.00 × 10 ⁴ .

The above novolak resins may be used alone or in combination of two or more kinds.

The novolac resin is contained in the photosensitive composition in an amount of 5 to 95.
It is preferable to contain it by weight percent.

Further, the vinyl polymer having a phenolic hydroxyl group is a polymer having a unit having the phenolic hydroxyl group in the molecular structure, and is represented by the following general formula [I] to
A polymer containing at least one structural unit represented by [V] is preferable.

[0056]

Embedded image

In the general formulas [I] to [V], R
₁ and R ₂ each represent a hydrogen atom, an alkyl group or a carboxyl group, and preferably a hydrogen atom. R
₃ represents a hydrogen atom, a halogen atom or an alkyl group,
Preferred is a hydrogen atom or an alkyl group such as a methyl group and an ethyl group. R ₄ and R ₅ represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and preferably a hydrogen atom. A represents an optionally substituted alkylene group that connects a nitrogen atom or an oxygen atom to an aromatic carbon atom, m represents an integer of 0 to 10, and B represents a substituent. Represents a phenylene group which may be substituted or a naphthylene group which may have a substituent.

The vinyl polymer having a phenolic hydroxyl group used in the present invention preferably has a copolymer type structure having the structural units represented by the general formulas [I] to [V]. As the monomer to be copolymerized,
For example, ethylene, propylene, isobutylene, butadiene, isoprene and other ethylenically unsaturated olefins,
For example, styrenes such as styrene, α-methylstyrene, p-methylstyrene, and p-chlorostyrene, for example,
Acrylic acids such as acrylic acid and methacrylic acid, for example,
Itaconic acid, maleic acid, unsaturated aliphatic dicarboxylic acids such as maleic anhydride, for example, methyl acrylate, ethyl acrylate, acrylate n-butyl, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, Phenyl acrylate, α-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, esters of α-methylene aliphatic monocarboxylic acid such as ethyl ethacrylate, for example, acrylonitrile, nitriles such as methacrylonitrile, for example, acrylamide. Amides such as, for example, acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-
Anilides such as methoxyacrylanilide, for example, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl esters such as vinyl acetate, for example, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, vinyl ethers such as β-chloroethyl vinyl ether, Vinyl chloride, vinylidene chloride, vinylidene cyanide, for example, 1-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-nitro Ethylene derivatives such as ethylene, for example, N-vinyl-based monomers such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidene and N-vinylpyrrolidone. These monomers are present in the polymer compound in a structure in which the unsaturated double bond is cleaved.

Of the above-mentioned monomers, aliphatic monocarboxylic acid esters and nitriles are preferable because they exhibit excellent performance for the purpose of the present invention.

These monomers may be bonded to the polymer used in the present invention in either a block or random state.

The vinyl polymer having a phenolic hydroxyl group is preferably contained in the photosensitive composition in an amount of 0.5 to 70% by weight.

As the vinyl polymer having a phenolic hydroxyl group, the above polymers may be used alone or in combination of two or more kinds. It can also be used in combination with other polymer compounds.

Further, a printout material capable of forming a visible image upon exposure can be added to the photosensitive layer of the present invention. The printout material is composed of a compound that generates an acid or a free radical upon exposure to light and an organic dye that changes its color tone by interacting with the generated acid or a free radical. Examples of the compound include o-naphthoquinonediazide-4-sulfonic acid halogenide described in JP-A-50-36209, trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A-53-36223. , JP Sho
O-6-naphthoquinonediazide-4 described in JP-A-55-6244
-Ester compound or amide compound of sulfonic acid chloride and phenol or aniline having an electron-withdrawing substituent, JP-A-55-77742, JP-A-57-148784
Examples thereof include halomethylvinyloxadiazole compounds and diazonium salts described in JP-A No.
Examples of organic dyes include Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), and Oil Blue # 603.
(Manufactured by Orient Chemical Industry Co., Ltd.), Sudan Blue II
(Manufactured by BASF), crystal violet, malachite green, fuchsin, methyl violet, ethyl violet, methyl orange, brilliant green, congo red, eosin, rhodamine 66 and the like.

In addition to the above-mentioned materials, a plasticizer, an organic acid, an acid anhydride and the like can be added to the photosensitive layer of the present invention, if necessary.

Further, in order to improve the oil sensitivity of the photosensitive layer, for example, p-tert-butylphenolformaldehyde resin, pn-octylphenolformaldehyde resin or these resins may be added to the photosensitive layer of the present invention.
A resin partially esterified with a quinonediazide compound may be added.

The photosensitive layer of the present invention can be formed by coating a support with a coating solution prepared by dissolving or dispersing a photosensitive composition comprising each of these components in a solvent and drying.

The coating method used for coating the photosensitive layer coating liquid on the support surface is a conventionally known method, for example, spin coating, wire bar coating, dip coating, air knife coating, spray coating, air spray coating, Methods such as electrostatic air spray coating, roll coating, blade coating and curtain coating are used.

For the photosensitive layer of the present invention, for example, a photosensitive composition is dissolved in a mixed solvent consisting of a good solvent of a low boiling point surfactant and a poor solvent of a high boiling point surfactant to apply a coating solution, It is formed by drying under at least two or more different temperature conditions.

In the present invention, when a plurality of photosensitive layers are provided, the photosensitive layer on the outermost surface is preferably the photosensitive layer of the present invention. Further, some or all of the plurality of photosensitive layers may be the photosensitive layer of the present invention.

The good solvent and the poor solvent are relative ones and are not particularly limited, but as a good solvent for the surfactant, 5 wt% of the surfactant at room temperature is used.
A solvent that can dissolve the above is used, and 5% by weight of the surfactant is used as a poor solvent for the surfactant at room temperature.
It is preferable to use a solvent that can dissolve less than. Further, the difference in boiling point between the good solvent and the poor solvent is preferably 20 ° C. or higher, and more preferably 30 ° C. or higher.

The photosensitive composition is dissolved in a mixed solvent consisting of a good solvent for a low boiling point surfactant and a poor solvent for a high boiling point surfactant, and the resulting coating solution is applied and at least two or more different temperature conditions are applied. It is not clear whether a photosensitive layer having a surfactant concentration distribution in which the surfactant concentration is high on the surface side and low in the vicinity of the support is formed by drying with. However, when the photosensitive composition is dissolved in a mixed solvent consisting of a good solvent having a low boiling point surfactant and a poor solvent having a high boiling point surfactant, and then dried, the boiling point is low and evaporation is first Fast good solvent evaporates from the surface, the content ratio of the poor solvent on the surface of the photosensitive layer increases, the surfactant precipitates accordingly, and the solution containing the surfactant diffuses from there to the further evaporation of the solvent. By being done On the surface side of the photosensitive layer can be present many surfactants, the above results are considered to be that obtained by performing drying at least two or more different temperature conditions.

The poor solvent and the good solvent are relatively determined, and the high boiling point and the low boiling point are relatively determined. What is meant by the poor solvent of the surfactant having a high boiling point is the solvent, and the low boiling point is low. It is not possible to clearly show the range of what a good solvent of a surfactant refers to, but a good solvent of a low boiling point surfactant used in the present invention, a poor solvent of a high boiling point surfactant. The following may be mentioned as examples.

In practice, in the present invention, these may be used by selecting from poor solvents for surfactants having a high boiling point and good solvents for surfactants having a low boiling point.

Examples of poor solvents for surfactants having a high boiling point Propylene glycol alkyl ethers (eg, propylene glycol monomethyl ether, propylene glycol monoethyl ether), dipropylene glycol alkyl ethers (eg, dipropylene glycol monomethyl ether, di Propylene glycol monoethyl ether), diethylene glycols [eg, dimethyl carbitol (DMDG), diethyl carbitol (DEDG), methyl carbitol], alcohols (eg, pentanol, hexanol, 3-methoxy-1-butanol), Methyl propyl ketone, methyl butyl ketone, diacetone alcohol, cyclopentanone, cyclohexanone.

Examples of good solvents for surfactants having a low boiling point: acetone, methyl ethyl ketone, 4-hydroxy-2-
Butanone, methyl lactate, cellosolves (eg methyl cellosolve, ethyl cellosolve).

The photosensitive layer of the present invention is dried under at least two or more different temperature conditions, but it is preferable to perform drying at a low temperature and then at a high temperature in the initial stage of the drying. Examples of these drying conditions include the following drying conditions. The combination of drying conditions can be selected by conducting a simple experiment.

Drying conditions of photosensitive layer Conditions: temperature: 20 ° C to 60 ° C, preferably 25 ° C to 55 ° C time: 10 seconds to 120 seconds, preferably 15 seconds to 110 seconds Condition temperature: 45 ° C to 90 ° C, preferably Is 50 ℃ ~ 85 ℃ time; 10 seconds ~ 120 seconds, preferably 15 seconds ~ 110 seconds Condition temperature; 70 ℃ ~ 150 ℃, preferably 65 ℃ ~ 145 ℃ time; 10 seconds ~ 120 seconds, preferably 15 seconds ~ 110 seconds condition temperature; 150 ℃ ~ time; 10 seconds ~ 120 seconds, preferably 15 seconds ~ 110 seconds The coating amount of the photosensitive layer coating solution, as a dry film thickness of the photosensitive layer is 0.
5 μm to 8.0 μm is preferable, and 1.0 μm to 4.0 μm is more preferable.

In the photosensitive lithographic printing plate of the present invention, the photosensitive layer may have two or more layers.

The surfactants used in the respective photosensitive layers may be the same or different, and
A plurality of surfactants may be present in each layer.

In the case of having two or more photosensitive layers, at least one of them may be the photosensitive layer of the present invention, and the other photosensitive layer may be the photosensitive layer of the present invention. It may be a photosensitive layer.

The coating amount of the photosensitive layer coating solution at this time is preferably 0.5 μm to 8.0 μm, more preferably 1.0 μm to 4.0 μm, as the dry film thickness of the photosensitive layer.

The positive-working photosensitive lithographic printing plate of the present invention can be made into a plate by exposing and developing it in a usual manner. For example, a transparent original image having a line image, a halftone dot image and the like is exposed in close contact with the photosensitive surface, and then the photosensitive layer in the non-image area is removed using an appropriate developing solution to obtain a relief image. To be

Light sources suitable for exposure include mercury lamps, metal halide lamps, xenon lamps, chemical lamps,
Examples include carbon arc lamps. Further, as the developing solution and the developing replenishing solution used for the development, an alkaline aqueous solution is preferable, and examples thereof include alkali metal silicates such as sodium silicate and potassium silicate, sodium hydroxide, potassium hydroxide, trisodium phosphate, An alkaline aqueous solution such as an aqueous solution of sodium diphosphate, sodium carbonate, potassium carbonate or the like can be used.

In the present invention, the developing solution and the developing replenishing solution used for developing the photosensitive lithographic printing plate are preferably those containing an alkali metal silicate. The alkali metal of the alkali metal silicate includes lithium, sodium and potassium, and potassium is the most preferable.

At the time of development, it is preferable that the development replenisher is appropriately replenished in accordance with the development processing amount of the photosensitive lithographic printing plate.

The preferred developing solution and developing replenishing solution are [SiO 2
₂ ] / [M] (wherein [SiO ₂ ] represents the molar concentration of SiO ₂ and [M] represents the molar concentration of alkali metal).
15 to 1.0, and the SiO ₂ concentration is 0.5 to 5.0 with respect to the total weight.
It is an aqueous solution of an alkali metal silicate which is wt%. Further, particularly preferably, [SiO ₂ ] / [M] of the developer is
0.25 to 0.75, the SiO ₂ concentration is 1.0 to 4.0% by weight, the development replenisher [SiO ₂ ] / [M] is 0.15 to 0.5, and S
The iO ₂ concentration is 1.0 to 3.0% by weight.

The pH of the developing solution and the developing replenisher is preferably
12 to 13.8.

The above-mentioned developers and development replenishers can contain water-soluble or alkali-soluble organic and inorganic reducing agents.

Examples of the organic reducing agent include phenol compounds such as hydroquinone, metol and methoxyquinone, amine compounds such as phenylenediamine and phenylhydrazine, and examples of the inorganic reducing agent include:
For example, sodium sulfite, potassium sulfite, ammonium sulfite, sodium hydrogen sulfite, sulfite salts such as potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite,
Examples thereof include phosphites such as sodium dihydrogen phosphite and dipotassium hydrogen phosphite, hydrazine, sodium thiosulfate, and sodium dithionite.

The water-soluble or alkali-soluble reducing agent can be contained in the developing solution and the developing replenishing solution in an amount of 0.05 to 10% by weight.

The developer and development replenisher may contain an organic acid carboxylic acid.

These organic acids, carboxylic acids, have carbon atoms
6 to 20 aliphatic carboxylic acids and aromatic carboxylic acids in which a benzene ring or a naphthalene ring is substituted with a carboxyl group are included.

The fat-proof carboxylic acid has 6 to 20 carbon atoms.
Alkanoic acid is preferable, and specific examples thereof include caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mistyric acid, palmitic acid, stearic acid, and the like, and particularly preferable is carbon. Number 6
~ 12 alkanoic acids. Further, the fat-proof carboxylic acid is
It may be a fatty acid having a double bond in the carbon chain or a fatty acid having a branched carbon chain. The aliphatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

Specific examples of the aromatic carboxylic acid include benzoic acid, o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, p-tert-butylbenzoic acid, o-aminobenzoic acid,
p-aminobenzoic acid, 2,4-dihydroxybenzoic acid,
2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-
Examples thereof include naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-naphthoic acid and 2-naphthoic acid.

The above aromatic carboxylic acids may be used as sodium or potassium salts or ammonium salts.

The content of the aliphatic carboxylic acid and the aromatic carboxylic acid may be at least 0.1 to 30% by weight.

The developer and development replenisher may contain the following anionic, nonionic and cationic surfactants and organic solvents.

As the anionic surfactant, higher alcohol (C ₆ -C ₂₂ ) sulfate ester salts [eg, sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, “Τeepol- 81 ''
(Trade name, manufactured by Shell Chemical Co., Ltd., secondary sodium alkylsulfate, etc.), aliphatic alcohol phosphate ester salts (eg, cetyl alcohol phosphate sodium salt, etc.), alkylaryl sulfonates (eg, dodecyl) Benzenesulfonic acid sodium salt, isopropylnaphthalenesulfonic acid sodium salt, dinaphthalenedisulfonic acid sodium salt, metanitrobenzenesulfonic acid sodium salt, and the like, alkylamide sulfonates (for example, C ₁₇ H ₃₃ CON (CH ₃ ) C
H ₂ SO ₃ Na) and sulfonates of dibasic fatty acid ester (for example, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester). Among these, sulfonates are particularly preferably used.

As the nonionic surfactant, both polyethylene glycol type and polyhydric alcohol type can be used.

Examples of nonionic surfactants include:
Examples thereof include compounds represented by the following general formulas [1] to [8].

[0101]

Embedded image

In the general formulas [1] to [8], R represents a hydrogen atom or a monovalent organic group, and a, b, c, m, n,
x and y each represent an integer of 1-40.

Examples of the organic group represented by R include a linear or branched alkyl group having 1 to 30 carbon atoms, an alkyl group having a substituent [for example, an aryl group (phenyl etc.)], and an alkyl moiety. Straight or branched carbon number 1 to 30
And an phenyl group which may have a substituent (for example, a hydroxyl group, the above-mentioned alkyl group, etc.) and the like.

Specific examples of the nonionic surfactant are shown below.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether,
Polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene behenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene stearyl amine, polyoxyethylene oleyl amine, polyoxyethylene stearic acid amide, Polyoxyethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene Glyceryl monostearate, polyoxyethylene propylene glycol monostearate, oxyethyl Oxypropylene block polymer, distyrenated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polyoxypropylene adduct, glycerol monostearate, sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, etc. .

The weight average molecular weight of the nonionic surfactant is
The range of 300 to 10,000 is preferred. The concentration of the nonionic surfactant in the developer can be at least 0.001 to 10% by weight.

Cationic surfactants are roughly classified into amine type and quaternary ammonium salt type, and any of these can be used.

Examples of the amine type include polyoxyethylene alkyl amine, N-alkyl propylene amine, N
-Alkyl polyethylene polyamine, N-alkyl polyethylene polyamine dimethyl sulfate, alkyl biguanide, long-chain amine oxide, alkyl imidazoline, 1-
Hydroxyethyl-2-alkylimidazoline, 1-acetylaminoethyl-2-alkylimidazoline, 2-
Alkyl-4-methyl-4-hydroxymethyloxazoline and the like can be mentioned.

Examples of the quaternary ammonium salt type are long-chain primary amine salt, alkyltrimethylammonium salt, dialkyldimethylethylammonium salt, alkyldimethylammonium salt, alkyldimethylbenzylammonium salt, alkylpyridinium salt, alkylquinoyl salt. Norinium salt, alkylisoquinolinium salt, alkylpyridinium sulfate, stearamidomethylpyridinium salt, acylaminoethyldiethylamine salt, acylaminoethylmethyldiethylammonium salt, alkylamidopropyldimethylbenzylammonium salt, fatty acid polyethylene polyamide, acylamino Ethylpyridinium salt, Acylcholaminoformylmethylpyridinium salt, Stearooxymethylpyridinium salt, Fatty acid triethanolamine, Fat Acid triethanolamine formate, trioxyethylene fatty acid triethanolamine,
Examples thereof include fatty acid dibutylaminoethanol, cetyloxymethylpyridinium salt, and p-isooctylphenoxyethoxyethyldimethylbenzil ammonium salt. ("Alkyl" in the examples of the above compounds has 6 carbon atoms.
The straight-chain or partially substituted alkyl of ˜20 is shown. Specifically, straight-chain alkyl such as hexyl, octyl, cetyl and stearyl is preferably used. ) Further, a cationic surfactant of a polymer having a cation component as a repeating unit, for example, a polymer containing a quaternary ammonium salt obtained by copolymerization with a lipophilic monomer can be contained.

The amount of the cationic surfactant added to the developer may be at least 0.001 to 10% by weight.

The weight average molecular weight is at least 300-500.
The range of 00 can be used.

As the surfactant, it is preferable to use a fluorinated surfactant containing a perfluoroalkyl group in the molecule. As such a fluorine-based surfactant,
Perfluoroalkyl carboxylate, perfluoroalkyl sulfonate, anion type such as perfluoroalkyl phosphate, amphoteric type such as perfluoroalkyl betaine, cation type such as perfluoroalkyltrimethylammonium salt and perfluoroalkylamine oxide, Perfluoroalkyl ethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, oligomer containing perfluoroalkyl group, hydrophilic group and lipophilic group, perfluoroalkyl group and parent A nonionic type such as an oily group-containing urethane may be mentioned.

The above surfactants can be used alone or in combination of two or more kinds.

The developer and the development replenisher may contain an organic solvent.

As the organic solvent, those having a solubility in water at 20 ° C. of not more than 10% by weight are preferable, and for example, ethyl acetate, propyl acetate, butyl acetate, benzyl acetate,
Ethylene glycol monobutyl acetate, butyl lactate,
Carboxylic acid esters such as butyl levulinate; Ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone; ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n Alcohols such as amyl alcohol, methyl amyl alcohol;
Alkyl-substituted aromatic hydrocarbons such as xylene; halogenated hydrocarbons such as methylene dichloride, ethylene dichloride and monochlorobenzene.

These organic solvents can be used alone or in combination of two or more.

Further, the following additives can be added to the developer and the development replenisher in order to enhance the developing performance. Examples of these additives include, for example, JP-A-58-75152.
Neutral salts such as NaCl, KCl and KBr described in JP-A-59-190952, chelating agents such as EDTA and NTA described in JP-A-59-190952, and [Co (N
H ₃ )] ₆ , Cl _{3 and} other complexes, amphoteric polymer electrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, JP-A-58-59444 Inorganic lithium compounds such as lithium chloride described, organic lithium compounds such as lithium benzoate described in JP-B-50-34442, organometallic surfactants containing Si, Ti, etc. described in JP-A-59-75255, The organic boron compounds described in JP-A-59-84241 are mentioned.

Further, known additives can be added to the developer and the development replenisher.

[0119]

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

Example [Preparation of Aluminum Plate] An aluminum plate having a thickness of 0.3 mm (material 1050, temper H16) was subjected to a degreasing treatment for 1 minute in a 5% sodium hydroxide aqueous solution kept at 60 ° C. , Washed with water, immersed in a 10% sulfuric acid aqueous solution kept at 25 ° C for 1 minute,
It was neutralized and further washed with water. This aluminum plate was placed in a 1.0 wt% hydrochloric acid aqueous solution at a temperature of 25 ° C. and a current density of 100 A.
Electrolytic surface roughening was performed with an alternating current under the conditions of / dm ² and a treatment time of 60 seconds. Then 6 in 5% aqueous sodium hydroxide
Desmut treatment is performed at 0 ° C for 10 seconds, then in a 20% sulfuric acid solution, temperature is 20 ° C, current density is 3 A / dm ² , treatment time is 1
The anodic oxidation treatment was performed under the condition of 1 minute. Then, soak in a 1% sodium nitrite aqueous solution kept at 80 ° C for 30 seconds,
After washing with water, it was dried at 80 ° C for 5 minutes to prepare a support.

[Preparation of photosensitive lithographic printing plate sample] The above-mentioned photosensitive layer coating liquid described in Table 1 was applied onto the above support using a wire bar, and dried under the following drying conditions described in Table 1,
Photosensitive planographic printing plate samples 1 to 4 were prepared. The film thickness of the photosensitive layer was 2 μm.

[0122]

[Table 1]

<Photosensitive Layer Coating Liquid Composition> (Photosensitive Layer Coating Liquid A) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin ( Weight average molecular weight 3000) and o-naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2 , 4-Bis (trichloromethyl) -6- (p-methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g methyl ethyl ketone / Diethyl carbitol = 50/50 100 ml

(Photosensitive Layer Coating Solution B) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) ) -6- (p-Methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Co., Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g Methyl ethyl ketone / diethyl carbitol = 70/30 100 ml

(Photosensitive Layer Coating Solution C) Novolak resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Polyethylene glycol # 2000 0.2 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) ) -6- (p-Methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Co., Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g Methyl cellosolve / ethyl cellosolve = 80/20 100 ml

(Photosensitive Layer Coating Solution D) Novolac resin (phenol / m-cresol / p-cresol molar ratio 10/54/36, weight average molecular weight 4000) 6.7 g pyrogallolacetone resin (weight average molecular weight 3000) and o -Naphthoquinonediazide-5-sulfonyl chloride condensate (esterification rate 30%) 1.5 g Polyethylene glycol # 2000 0.6 g Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.08 g 2,4-bis (trichloromethyl) ) -6- (p-Methoxystyryl) -s-triazine 0.15 g FC-430 (Sumitomo 3M Ltd.) 0.03 g cis-1,2-cyclohexanedicarboxylic acid 0.2 g water / methanol = 5/5 25 g

<Drying condition after coating photosensitive layer> (Drying condition A) Drying at 40 ° C for 1 minute (Drying condition B) Drying at 55 ° C for 1 minute (Drying condition C) Drying at 100 ° C for 1 minute

The sensitivity, contrast and printing durability of the obtained photosensitive lithographic printing plate sample were evaluated by the following. Further, the difference in halftone dot sensitivity variation was determined, and the range of suitable developing conditions was determined. The obtained results are shown in Table 2.

<< Evaluation Method >> = Evaluation of Sensitivity = A sample tablet for sensitivity measurement (Eastman Kodak No. 2, 21-step gray scale with 0.15 density difference) was attached to the sample, and a 4kW metal halide lamp (large) Exposure was performed from a distance of 90 cm using a Japanese screen vio Quick manufactured by Nihon Screen Co., Ltd. as a light source.

Next, this sample was treated with a developer having the following composition at 27 ° C.
Developed for 20 seconds.

<Developer composition> A Potassium silicate (manufactured by Nippon Kagaku Co., Ltd.) 120 g Potassium hydroxide (50% aqueous solution) 30 g Pure water 500 g The exposure time at which 3.0 steps of the above step tablet was completely cleared was taken as the sensitivity.

= Evaluation of high contrast property = In the evaluation of sensitivity, in the planographic printing plate in which 3.0 steps of the step tablet obtained by development is completely clear, the solid step number of the gray scale developed image is determined,
Hardness was evaluated from the value of [solid step number-clear step number].
The smaller this value, the better the contrast. ○: [Solid level-Clear level] is 7.0 or less △: [Solid level-Clear level] is 7.0 to 10.0 ×: [Solid level-Clear level] is greater than 10.0

= Evaluation of printing durability = A sample of a sensitivity measuring step tablet (Eastman Kodak No. 2, 21-step gray scale with a density difference of 0.15) was closely attached to the sample, and a 4kW metal halide lamp (Dainippon Screen) was used. Exposure was carried out from a distance of 90 cm using vio Quick manufactured by Co., Ltd. as a light source.

Next, this sample was treated with a developer having the following composition at 27 ° C.
Developed for 20 seconds.

<Developer composition> A Potassium silicate (manufactured by Nippon Kagaku) 120 g Potassium hydroxide (50% aqueous solution) 30 g Pure water 500 g The obtained lithographic printing plate was used as a printing machine G manufactured by Heidelberg Co.
Over TO, coated paper, printing ink (New Bright Beni manufactured by Toyo Ink Mfg. Co., Ltd.) and fountain solution (Konica Corporation)
SEU-3 (2.5% manufactured by SEU-3) is used for printing, and printing is continued until defective solidification appears in the solid part of the image on the printed matter or ink is non-printed in the non-image area, and the number of printed sheets at that time is counted. The printing durability was defined as this number.

= Judgment of the range of suitable development conditions (dot sensitivity) = Plate control wedge (UGRA PCW) for the sample
From a distance of 90 cm using a 4 kW metal halide lamp (vio Quick made by Dainippon Screen Co., Ltd.) as a light source.
It was exposed for 0 seconds. Next, this sample was developed with a developer obtained by diluting SDR-1 (manufactured by Konica Corp.) developer 5 times and 9 times with water at 27 ° C. for 20 seconds.

[0137] A plate control wedge (UGRA PCW) was visually observed with a magnifying glass of 25 times for those developed with the above 5 times diluted solution and those developed with the 9 times diluted developing solution.
The reproducibility of the circular patch formed by was observed. It is said that the smaller the circular patch variation of UGRA PCW between the one developed with 5 times dilution and the one developed with 9 times diluted developer, the smaller the difference in halftone dot sensitivity fluctuation and the wider range of suitable development conditions. it can.

[0138]

[Table 2]

Further, the concentration distribution of the surfactant in the photosensitive layer was determined. = Concentration distribution of surfactant = (1) A step tablet for sensitivity measurement (Eastman Kodak No. 2, 21-step gray scale with a concentration difference of 0.15) was closely attached to the sample, and a 4kW metal halide lamp (Dainippon Exposure is performed from a distance of 90 cm using a screen (vio Quick, manufactured by Screen Co., Ltd.) as a light source.
Development was carried out at 20 ° C. for 20 seconds to prepare a developed sample in which the 3.0 step of the above step tablet was completely clear.

In the developed sample thus obtained, the optical density (OD) with an orange filter was measured using a Macbeth reflection densitometer, and the optical density was 0.9, 0.8, 0.7, 0.6, 0.
The contact angle was measured at the parts of 5, 0.4 and 0.3. Table 3 shows the obtained results. Further, the relationship of the contact angle with respect to each optical density shown in Table 3 is shown in FIG.

<Developer composition> A Potassium silicate (Nippon Kagaku) 120 g Potassium hydroxide (50% aqueous solution) 30 g Pure water 500 g Contact angle measurement device C manufactured by Kyowa Kagaku Co., Ltd.
It was measured using distilled water at a temperature of 20 ° C. and a humidity of 60% RH using AD.

It is indicated that the higher the contact angle in the high-concentration portion, and the larger the tendency of the contact angle to decrease at the low-concentration stage, the higher the surfactant concentration on the surface side.

[0143]

[Table 3] Table 4 shows the relationship between the optical density and the sensitivity measuring step tablet in each sample.

[0144]

[Table 4]

[0145]

The photosensitive lithographic printing plate of the present invention is excellent in contrast, has a wide range of suitable developing conditions, has sufficient printing durability without deterioration of film strength, and has high sensitivity. Have

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship of a contact angle with respect to each optical density of Samples 1 to 4.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Matsubara 1 Sakura-cho, Hino-shi, Tokyo Konica Stock Company

Claims (6)

[Claims] 1. A photosensitive lithographic printing plate in which a support is provided with at least one photosensitive layer containing an o-quinonediazide compound and a surfactant, the concentration of the surfactant in the photosensitive layer is high on the surface side, In addition, the concentration distribution is such that it is lower on the side closer to the support, and the concentration of the surfactant on the side closer to the support is 2/3 of the average concentration of the surfactant in the photosensitive layer. A photosensitive lithographic printing plate characterized by being: 2. A photosensitive lithographic printing plate comprising a support and at least one photosensitive layer containing an o-quinonediazide compound and a surfactant, wherein the surfactant in the photosensitive layer is sensitive to the photosensitive lithographic printing plate. When contacting a measuring step tablet (21 steps with a density difference of 0.15 each), exposing and developing so that the 3.0 step of the step tablet is completely clear, and making a plate, the contact angle of the printing plate surface is a solid step. A photosensitive lithographic printing plate having a density distribution of 90 degrees or more and 40 degrees or less in the range of 4.0 to 3.0 steps. 3. The photosensitive lithographic printing plate according to claim 1, wherein the number of the photosensitive layers containing the o-quinonediazide compound and the surfactant provided on the support is one. 4. A mixed solvent comprising a support and a photosensitive composition containing an o-quinonediazide compound and a surfactant, and a good solvent for the surfactant having a low boiling point and a poor solvent for the surfactant having a high boiling point. 4. The method for producing a photosensitive lithographic printing plate as claimed in claim 1, wherein the coating solution dissolved in is applied and dried under at least two different temperature conditions. 5. The method for producing a photosensitive lithographic printing plate as claimed in claim 4, wherein the drying is carried out at a low temperature in the initial stage and then at a high temperature. 6. A mixed solvent comprising a photosensitive composition containing an o-quinonediazide compound and a surfactant on a support and a good solvent for the surfactant having a low boiling point and a poor solvent for the surfactant having a high boiling point. 4. The method for producing a photosensitive lithographic printing plate as claimed in claim 1, wherein the coating solution dissolved in is applied, then dried at a low temperature in the initial stage, and then dried at a high temperature.