JPH02289388A - Photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To obtain a photosensitive lithographic printing plate which does not leave a component of a photosensitive layer in a non-picture part after exposure and development, has so called excellent developing property and maintains sufficient water retentivity in the non-picture part by placing a photosensitive layer on the surface after the surface of a pretreated supporter is treated with a water solution containing nitrous acid or nitrite. CONSTITUTION:Before a photosensitive layer is placed on the surface of a pretreated supporter, the surface of the layer is treated with a water solution containing nitrous acid or nitrite. For the nitrate used for this treatment, the nitrite of groups Ia, IIa, IIb, IIIb, IVa, IVb, VIa, VIIa and VIII metal in a periodical table, or their ammonium salt, that is, ammonium nitrite, are listed up, and for their metallic acid, LiNO2, etc., are preferable. The water solution used here normally contains 0.001 to 10wt.% of nitrous acid or nitrite. Conditions for treating the surface of the supporter with this solution are to immerse the pretreated supporter in 15 to 300sec in a temperature range from a room temperature to about 100 deg.C. Photosensitive material employed in the photosensitive layer is photo-crosslinkable resin component normally used for the lithographic printing plate, for instance. Consequently, the soil of a non-picture part is prevented from occurring to improve water retentivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate having an improved parent layer.

[Conventional technology]

Conventionally, a photosensitive lithographic printing plate, such as a positive-working photosensitive printing plate, has an ink-receptive photosensitive layer provided on a support having a parent layer. When image exposure is performed and the exposed photosensitive layer is then developed using a developer, the photosensitive layer in the exposed areas is removed and the surface of the hydrophilic support is exposed, while the photosensitive layer in the exposed areas is removed from the support. It remains on the surface to form ink-receptive image areas, thereby yielding a lithographic printing plate.

Such a lithographic printing plate uses the repulsion between water and oil to perform printing. Specifically, when the non-image area of the printing plate is moistened with water and then ink is applied to the printing plate, the ink is repelled by the dampening water in the non-image area, so that the ink selectively adheres only to the image area. When the ink in the image area is transferred to a transfer object, a printed matter having an image corresponding to the image area is obtained.

Therefore, as a support for obtaining such a lithographic printing plate, it is necessary to use a support that is hydrophilic and has excellent water retention properties when wetted with water, and has good adhesion to the photosensitive layer that forms the image area that receives printing pressure. It has to be something. In addition, as a photosensitive layer,
In addition to being required to have ink receptivity and high sensitivity to exposure, the most important condition is that it must have high printing durability.

An aluminum plate is the best support that satisfies these conditions, and in order to obtain sufficient adhesion between the aluminum plate and the photosensitive layer, a surface treatment method is used to mechanically roughen the surface of the support. For example, boulder reining,
Various methods such as wire graining and brushed raining are described in Japanese Patent Publication No. 50-40047 and Japanese Patent Publication No. 51-460.
It is described in Publication No. 03, etc. In addition, special public service
No. 123, U.S. Patent No. 4.087.341, and Japanese Unexamined Patent Publication No. 53-67507, etc., disclose that the surface of an aluminum plate is uniformly coated with a direct current or alternating current using a hydrochloric acid bath, a nitric acid bath, etc. An electrolytic surface roughening method that forms a dense grained shape is described. Furthermore, JP-A-56-150595 describes a method of controlling the adhesion between the support and the photosensitive layer by subjecting the surface of the support to a sealing treatment using hot water, a sealing treatment using a silicate, or the like. ing.

In addition to providing sufficient adhesion between the support and the photosensitive layer, the support such as an aluminum plate is further subjected to surface treatment to improve its hydrophilicity and water retention. Publication No. 56-22063, U.S. Patent No. 2.246.683, U.S. Patent No. 3.160.50
No. 6 describes that the hydrophilicity and water retention of the metal surface can be improved by chemically treating the metal surface with potassium fluorozirconate to form a film. Further, JP-A-53-131102 describes a support whose hydrophilicity and water retention are improved by treating it with an aqueous potassium fluorozirconate solution and then with an aqueous sodium silicate solution.

However, with these methods, if the stain prevention effect of the non-image area of the planographic printing plate obtained by development treatment is sufficiently improved, problems arise in stiffness resistance and chemical resistance, and printing durability and processing chemical resistance are deteriorated. If an attempt is made to improve this, the stain prevention effect in the non-image area becomes insufficient, and it has been difficult to improve all three aspects: stain prevention in the non-image area, printing durability, and processing chemical resistance.

This phenomenon becomes more noticeable when a burning treatment, which is commonly carried out as a means of improving printing durability, is carried out, and the lithographic printing plate obtained from the support treated by the above method is It is no longer suitable for actual printing use.

Therefore, as a result of extensive research in view of the above-mentioned problems, the inventors of the present invention have mainly treated the surface of the aluminum support using a specific treatment, thereby maintaining high printing durability while at the same time The present inventors have discovered that a photosensitive lithographic printing plate can be obtained which maintains sufficient water retention and does not cause staining in non-image areas, and has completed the present invention.

[Purpose of the invention]

Therefore, the first object of the present invention is to provide a photosensitive lithographic printing plate that has excellent developability, in which no components of the photosensitive layer remain in non-image areas after exposure and development, and maintains sufficient water retention in non-image areas. Our goal is to provide the following.

A second object of the present invention is to provide a photosensitive lithographic printing plate that has high rigidity resistance and does not stain non-image areas.

[Structure of the invention]

The above-mentioned object of the present invention is achieved by a photosensitive lithographic printing plate characterized in that the surface of a pretreated support is treated with an aqueous solution containing nitrous acid or nitrite, and then a photosensitive layer is provided on the surface. be done.

[Effect]

In the present invention, after pre-treating the surface of the support, this surface is further treated with an aqueous solution containing nitrous acid or nitrite, so that when a photosensitive lithographic printing plate is developed, the non-image area becomes stronger than ever before. Since components in the photosensitive layer that have been adsorbed and cannot be removed, particularly resin components, can be easily removed, water retention in non-image areas can be maintained sufficiently.

[Detailed description of the invention]

The present invention will be explained in more detail below.

The present invention is characterized in that before forming a photosensitive layer on the surface of a pretreated support, the surface is treated with an aqueous solution containing nitrous acid or nitrite, thereby preventing staining of non-image areas. improves water retention.

Examples of nitrites used in the present invention include Ia, na, Irb, nlb, and IVa of the periodic table.

Examples include nitrites or ammonium salts of metals in the IVb, Vla, and ■a1■ groups, that is, ammonium nitrite. Examples of the metal salts include LiN0. , NaNO
2, KNO,,ug(No2)z,Ca(No,),,
Zn(NOz)z, AI(NOz)s, Zr(Now)
as 5n(NOx) Cr(NOx)s, Co(
Not)z, MfI(NOx)x, N1(NJ)z, etc. are preferred, and alkali metal nitrites are particularly preferred. Of course, two or more kinds of such nitrites can be used in combination, and further, they can also be used in combination with nitrous acid. The aqueous solution containing nitrite or nitrite used in the present invention is generally an aqueous solution containing 0.001 to 10% by weight of nitrite or nitrite.

When treating the surface of the support with the above treatment liquid, the treatment conditions include immersing the pretreated support for 15 to 300 seconds at a temperature range from room temperature to about 100°C, or supporting the treatment liquid. Preferably applied to the body.

As a preferred embodiment of the present invention, in an aqueous solution containing 0.01 to 2% by weight of sodium nitrite at 50 to 80°C,
Examples include a treatment in which the support is immersed for 180 seconds, and more preferably a treatment in which the support is immersed in an aqueous solution containing 0.05 to 1% by weight of sodium nitrite at 70 to 80°C for 50 to 80 seconds. The support treated with an aqueous solution containing nitrous acid or nitrite salts is then preferably dried.

Additives can be added to the aqueous solution containing nitrous acid or nitrite salts, if necessary. Examples include water-soluble polymers and surfactants.

The support used in the present invention is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as metal plates such as aluminum, magnesium, zinc, chromium iron, copper, and nickel; Examples include alloy plates of these metals, and metal plates coated with chromium, zinc, copper, nickel, aluminum, iron, etc. by plating or vapor deposition may also be used. Among these, a preferred support is aluminum or an alloy thereof.

The support used in the present invention is pretreated before being treated with nitrous acid or an aqueous solution containing nitrite, and this pretreatment includes degreasing and sand graining, which are commonly employed in this technical field. There is type handling.

Grain treatment is a method of mechanically roughening the surface, and is referred to as a so-called mechanical surface roughening method, and includes methods such as pole polishing, brush polishing, blast polishing, and puff polishing. It is also possible to use a so-called electrical surface roughening method in which the surface is electrically roughened; for example, the support can be subjected to electric field treatment using alternating current or direct current in an electrolytic solution containing hydrochloric acid, nitric acid, or the like.

Scots are formed on the surface of the support obtained by the above-mentioned grain pattern treatment, so in order to remove these scotts, it is generally necessary to carry out treatments such as water washing or alkali etching as appropriate. preferable. Examples of such treatments include the alkali etching method described in Japanese Patent Publication No. 48-28123 and the sulfuric acid descott method described in Japanese Patent Application Laid-open No. 53-12739.

When the support used in the present invention is an aluminum support, after the above-mentioned pretreatment, the support is usually anodized to improve wear resistance, chemical resistance, and water retention. to form an oxide film. In this anodic oxidation, sulfuric acid and/or phosphoric acid is generally used at a concentration of 10 to 50%.
% aqueous solution as an electrolyte and a current density of 1-1OA/d.
(2) The method of electrolysis in 2 is preferably used, but other methods include the method of electrolyzing at high current density in sulfuric acid described in U.S. Patent No. 1,412.768, and the method of electrolysis in U.S. Pat.
There is a method of electrolysis using phosphoric acid described in the specification of No. 1.661.

The most preferred support for use in the present invention is an aluminum support with an anodized coating.

The treatment applied to the support itself to improve the adhesion of the support to the photosensitive layer is not particularly limited, and a primer layer or the like may be provided as necessary.

The primer layer includes, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin. , polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, and the like.

In addition, as the anchor agent constituting the above-mentioned brimer layer,
For example, silane coupling agents, silicone primers, etc. can be used, and organic titanates and the like are also effective.

The photosensitive lithographic printing plate of the present invention has a photosensitive layer provided on the support obtained as described above, but the photosensitive material used in this photosensitive layer is not particularly limited. Various types of materials commonly used in photosensitive lithographic printing plates, such as those listed below, are used.

1) Photocrosslinkable photosensitive resin composition The photosensitive component in the photocrosslinkable photosensitive resin composition is composed of a photosensitive resin having an unsaturated double bond in the molecule, and is disclosed in, for example, US Pat. No. 3.030. Specification No. 208, No. 3.4
Photosensitive resins and polymers containing -CH-CH-C0- as a photosensitive group in the polymer main chain, as described in Specification No. 35,237 and Specification No. 3.622.320, etc. Examples include polyvinyl cinnamate having a photosensitive group in the side chain.

2) Photopolymerizable photosensitive resin composition A photopolymerizable composition containing an addition-polymerizable unsaturated compound, consisting of a monomer having a double bond and a polymer binder, and a typical example of such a composition. For example, U.S. Pat. No. 2,760,863 and U.S. Pat.
It is described in the specification of No. 504, etc.

This photopolymerizable photosensitive resin composition contains photopolymerization initiators commonly known in this technical field (for example, benzoin derivatives such as benzoin methyl ether, benzophenone derivatives such as benzophenone, f-, t-xanthone derivatives, and anthraquinone derivatives). , acridone derivatives, etc.) are added.

3) Photosensitive composition containing a diazo compound The diazo compound in this photosensitive composition is, for example, a diazo resin preferably represented by a condensate of an aromatic diazonium salt and formaldehyde or acetaldehyde. Particularly preferred are salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde, such as reaction products of hexafluoroborophosphates, tetrafluoroborates, perchlorates or periodates with said condensates. diazo resin inorganic salt, and U.S. Patent No. 3
．． As described in No. 300,309,
Examples include diazo resin organic salts which are reaction products of the above condensates and sulfonic acids. Furthermore, diazo resins are preferably used together with binders. Various polymer compounds can be used as such a binder, but monomers having an aromatic hydroxyl group such as those described in JP-A No. 54-98613, such as N-(4 −
Hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide% o-1m-1 or p-hydroxystyrene, 0-1■-1 or p-
Copolymers of hydroxyphenyl methacrylate, etc. and other monomers, with hydroxyethyl acrylate units or hydroxyethyl methacrylate units as the main repeating unit as described in U.S. Pat. No. 4,123.276 Polymers Containing Shellac, natural resins such as rosin, polyvinyl alcohol, U.S. Patent No. 3.7
Polyamide resins as described in U.S. Pat. No. 51.257, linear polyurethane resins as described in U.S. Pat. Epoxy resins condensed from A and epichlorohydrin, cellulose derivatives such as cellulose acetate and cellulose acetate phthalate are included.

4) Photosensitive composition 0- containing O-quinonediazide compound
In a photosensitive composition containing a quinonediazide compound,
It is preferable to use an 0-quinonediazide compound and an alkali-soluble resin together.

Examples of the 0-quinonediazide compound include ester compounds of 0-naphthoquinonediazide sulfonic acid and polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include phenol, 0-
Cresol, 1-cresol, p-cresol, 3.5
Examples include m-phenols such as xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, and trihydric phenols such as pyrogallol and 70 loglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol-formaldehyde resin, ■-cresol e-formaldehyde resin, @-1p-mixed cresol-formaldehyde resin, and pyrogallol-acetone resin.

The condensation rate of 0-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol of the 0-naphthoquinonediazide compound (reaction rate with respect to one OH group) is 15 to 80%.
is preferable, and more preferably 20 to 45%.

Further, as the O-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example, known 1,2-benzoquinonediazide sulfonic acid ester, 1,2-naphthoquinonediazide sulfonic acid ester, 1,2-benzoquinonediazide sulfonic acid amide, 1,2-su7toquinonediazide sulfonic acid amide, etc. - quinonediazide compounds, more specifically J. Kossar
"Light Sensitive Systems J ("Li
ght-Sensitive Systems”) Part 3
pp. 39-352 (1965), John Wiley & Sons
Company New York) and Double Ninis Day Forest (Stomach.S.DeF).

Rest) “Photoresist” (“PhOIOreS
iSt”) Volume 50.

(1975), Me Gray-Hi
l1) 1,2-benzoquinonediazide-4-sulfonic acid phenyl ester, as described by the company (New York);
1.2.1'2'-di(benzoquinone diazide-4-
sulfonyl)-dihydroxybiphenyl, 1,2-benzoquinonediazide-4-(N-ethyl-naphthyl)-sulfonamide, 1,2-su7toquinonediazide-5-sulfonic acid cyclohexyl ester, l-(1.2
-su7toquinonediazido-5-sulfonyl)-3.5-
Dimethylpyrazole, 1,2-naphthoquinonediazide-
5-Sulfonic acid-4'-hydroxydiphenyl-4'-
Azo-β-naphthol ester, N,N-di(1.2
-naphthoquinonediazide-5-sulfonyl)-aniline, 2'-(1,2-naphthoquinonediazide-5-sulfonyloxy)-1-hydroxy-anthraquinone, 1.
2-Naphthoquinonediazide 5-sulfone II-2.

4-dihydroxybenzophenone ester, 1.2-naphthoquinonediazide-5-sulfonic acid-2.3.4-trihydroxybenzophenone ester, 2 moles of 1.2-naphthoquinonediazide-5-sulfonic acid chloride and 4.
Condensate of 1 mole of 4'-diaminobenzophenone, l,2
- a condensate of 2 moles of naphthoquinonediazide-5-sulfonic acid chloride and 1 mole of 4,4'-dihydroxy-1.1'-diphenylsulfone; Condensate of 1 mol of purprogalin, l,2-naphthoquinonediazide-5-(N
-dihydroabiethyl)-sulfonamide etc. 1.2
- Quinonediazide compounds can be exemplified. or,
Special Publication No. 37-1953, No. 37-3627, No. 37
-13109, 40-26126, 40-38
No. 01, No. 45-5604, No. 45-27345,
Also included are 1,2-quinonediazide compounds described in JP-A-51-13013, JP-A-48-96575, JP-A-48-63802, and JP-A-48-63802.

Among the above 0-quinonediazide compounds, it is obtained by reacting l,2-benzoquinonediazide sulfonyl chloride or 1,2-naphthoquinonediazide sulfonyl chloride with a pyrogallol acetone condensation resin or 2,3,4-trihydroxybenzophenone. -Quinone diazide ester compounds are particularly preferred.

As the O-quinonediazide compound used in the present invention, each of the above compounds may be used alone, or two or more thereof may be used in combination.

The proportion of the 0-quinonediazide compound used in the present invention in the photosensitive composition is preferably 5 to 60% by weight,
Particularly preferably, it is 10 to 50% by weight.

Examples of the alkali-soluble resins used in the photosensitive composition of the present invention include novolac resins, vinyl polymers having phenolic hydroxyl groups, and polyhydric phenols described in JP-A-55-57841. Examples include condensation resins with aldehydes or ketones.

Examples of the novolak resin used in the present invention include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin as described in JP-A-55-57841, JP-A-55-57841; Examples include copolycondensate resins of p-substituted phenol and phenol or cresol and formaldehyde as described in Japanese Patent Publication No. 55-127553.

The molecular weight (polystyrene standard) of the novolak resin is:
Preferably, the number average molecular weight Mn is 3.00X 10” to 7
．． 50X 10', weight average molecular weight My is 1. OOX
103 to 3.00×101, more preferably Mn is 5.
00x 10" ~ 4.0OX10', My is 3.00
X10' to 2.00X10'.

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

The proportion of the novolak resin in the photosensitive composition of the present invention is 5 to 95% by weight.

Furthermore, the vinyl polymer having a phenolic hydroxyl group used in the present invention is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and is a polymer having a unit having a phenolic hydroxyl group in its molecular structure.
Polymers containing at least one structural unit of 1) to (V) are preferred.

-Sailor (I) General formula (n) (CRr R2CRsteC00(A:1)-68-OH -Sailor [■] General formula (IV) General formula [v] OH In the formula, R4 and R1 are respectively It represents a hydrogen atom, an alkyl group or a carboxyl group, preferably a hydrogen atom.

R3 represents a hydrogen atom, a norogen atom, or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R4 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom. A represents an alkylene group which may have a substituent and which connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, ■ represents an integer from 0 to 1O, and B may have a substituent. Represents a phenylene group or a naphthylene group which may have a substituent.

The polymer used in the photosensitive composition of the present invention preferably has a copolymer type structure, and the above-mentioned - Shipman CI
) to (V), examples of monomer units that can be used in combination with the structural units shown respectively include ethylene,
Ethylenically unsaturated olefins such as propylene, imbutylene, butadiene, isoprene, etc., such as styrene, α
- Styrenes such as methylstyrene, p-methylstyrene and p-chlorostyrene; acrylic acids such as acrylic acid and methacrylic acid; e.g. itaconic acid and maleic acid;
Unsaturated aliphatic dicarboxylic acids such as maleic anhydride, such as methyl acrylate, ethyl acrylate, acrylic acid n
-butyl, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate,
Esters of σ-methylene aliphatic monocarboxylic acids such as methyl a-chloroacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate; nitrites such as acrylonitrile and methacrylonitrile; amides such as acrylamide; Anilides such as acrylanilide, p-chloroacrylanilide, ■-nitroacrylanilide, and ■-methoxyacrylanilide, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, such as methyl vinyl ether, ethyl Vinyl ethers such as vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as l-methyl-1-methoxyethylene, 1,1-dimethoxyethylene, l,2
- Ethylene derivatives such as dimethoxyethylene, 1,1-dimethoxycarbonylethylene, l-methyl/l-nitroethylene, such as N-vinylpyrrole, N-vinylcarbasol, N-vinylindole, N-vinylpyrrolidone, N - Vinyl monomers such as N-vinyl compounds such as vinylpyrrolidone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, aliphatic monocarboxylic acid esters and nitriles exhibit excellent performance for the purpose of the present invention and are therefore preferred.

These monomers may be bound in the polymer of the present invention in either a block or random manner.

The proportion of the vinyl polymer used in the present invention in the photosensitive composition is 0.5 to 70% by weight.

As the vinyl polymer used in the present invention, the above-mentioned polymers may be used alone or in combination of two or more.

Moreover, it can also be used in combination with other polymer compounds.

A printout material can be added to the photosensitive composition that causes the formation of a visible image upon exposure to light. The printout material is composed of a compound that generates an acid or a free radical when exposed to light, and an organic dye that changes its color tone by interacting with the compound. 50-36
0-su7toquinone diazido 4- described in Publication No. 209
Sulfonic acid halogenides, trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A No. 53-36223, and 0-7toquinonediazide-4-sulfone described in JP-A-55-6244. Ester or amide compounds of acid chloride and phenols having electron-withdrawing substituents, or anilic acid;
JP-A-55-77742, JP-A-59-148784
Examples include halomethylvinyloxadiazole compounds and diazonium salts described in No.

Examples of the organic dyes include Victoria Pure Blue BOI (manufactured by Odugaya Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), and Oil Blue 4603.
(manufactured by Orient Chemical Industry Co., Ltd.), Sudan Blue II
(manufactured by BASF), crystal violet, malachite green, 7kushin, methyl violet, ethyl violet, methyl orange, brilliant green,
Examples include Fungo Red, Eosin, and Rhodamine 6G. In addition to the above materials, the photosensitive composition also includes
Plasticizers, surfactants, organic acids, acid anhydrides, etc. can be added as necessary.

Furthermore, the photosensitive composition of the present invention may contain, for example, p-1ert-butylphenol formaldehyde resin, p-n-octylphenol formaldehyde resin, or an 0-quinonediazide compound in order to improve the oil sensitivity of the photosensitive composition. It is also possible to add partially esterified resins and the like.

The photosensitive lithographic printing plate of the present invention can be produced by dissolving each of these components in the following solvent and applying and drying the solution on the surface of the support of the present invention to provide a photosensitive layer.

Solvents that can be used to dissolve each component of the photosensitive composition of the present invention include methyl cellosolve, ethyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, diethylene glycol 7-methyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol Methyl ethyl ether, diethylene glycol diethyl ether, diethyl glycol monoisoglobil ether,
Propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol 7-methyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, ethyl formate,
Propyl formate, butyl formate, amyl formate, methyl acetate,
Ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, methyl ethyl ketone, cyclohexanone, methyl cyclohexanone, diacetone alcohol, acetylacetone, γ-butyrolactone, etc. can be mentioned.

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

The coating method used in coating the surface of the support with the photosensitive composition used in the present invention includes conventionally known methods, such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, and blade coating. And curtain coating etc. are possible.

At this time, the coating amount varies depending on the application, but is preferably 0.05 to 5.0 g/a+2 in terms of solid content.

When using the photosensitive lithographic printing plate thus obtained,
Conventional methods can be applied, such as exposing a transparent original image having a line image, halftone image, etc. in close contact with the photosensitive surface, and then using a suitable developer to make the non-image areas photosensitive. By removing the layer a relief image is obtained.

As a light source suitable for exposure, a mercury lamp, a metal/\Ride lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, etc. are used.

The developer used for development is preferably an alkaline aqueous solution, such as an aqueous solution of sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, sodium carbonate, potassium carbonate, etc. There is an aqueous alkaline solution. The concentration of the alkaline aqueous solution at this time varies depending on the photosensitive composition and the type of alkali, but is generally in the range of 0.1 to 10% by weight. It is also possible to add organic solvents such as.

〔Example〕

EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded.

Examples 1 to 5 Preparation of Support-1 An aluminum plate (material 1050, tempered H16) with a thickness of 0.3 mm was degreased in a 5% aqueous solution of caustic soda at 65°C for 1 minute, then washed with water, and 25% in aqueous nitric acid solution
℃ for 1 minute, neutralized, and then washed with water. This aluminum plate was subjected to electrolytic surface treatment in a 0.3 mol/Q nitric acid aqueous solution at 30°C for 30 seconds at an AC current density of 50 A/d2, and then desmutted in a 5% caustic soda aqueous solution at 60°C for 10 seconds. Perform processing. Then in a 20% sulfuric acid solution at a temperature of 20°C.
, an electric density of 3 A/d+a'' and a treatment time of 1 minute, and further a hot sealing treatment was performed with hot water at 80'O for 20 seconds.

The aluminum plate subjected to the above treatment was immersed in a 1% aqueous sodium nitrite solution at 80'O for 1 minute.

After washing with water, it was dried at 80°C for 5 minutes.

Preparation of Support-2, 3, 4, and 5 Support-2, 3,4.

Got 5.

Support - 21% potassium nitrite aqueous solution // 3 1% calcium nitrite aqueous solution tt
4 1% ammonium nitrite aqueous solution〃 51% nickel nitrite aqueous solution Preparation of photosensitive plate printing plate sample I-1 A photosensitive composition coating solution (1) having the following composition was coated on the support-1 prepared as above with a wire. Apply using a bar, 80
Dry for 2 minutes at °C. The coating film thickness was 2.2 g/layer.

(Photosensitive composition coating liquid (1) composition) Novolak resin *A 6.7g0-
Quinonediazide compound *B 1.5g Surfactant *CO, 2g Victoria Pure Blue BO) I (manufactured by Hodogaya Chemical Co., Ltd.) 0.08g
Compound that generates halogen free radicals *D 0.15g Methyl Cellosolve 100m12 Photosensitive lithographic printing plate sample I-1 was exposed to 8IIIW/Cl112 for 60 seconds using a 2kw metal halide lamp, and developed using a commercially available developer. 5DR-1 (Konica Corporation)
Using a 5-fold diluted solution (manufactured by), the development time was 30 seconds, and the development temperature was 2.
The process was carried out at 5°C to obtain a lithographic printing plate sample 1-1.

Preparation of photosensitive lithographic printing plate samples I-2, 3, 4, and 5 The above photosensitive lithographic printing plate samples 1- Photosensitive lithographic printing plate sample I2.3.4.5 was prepared in the same manner as in Example 1.

These samples were exposed and developed in the same manner as in the case of photosensitive planographic printing plate 1-1, and planographic printing plate sample 1-2.3 was prepared.
．． I got 4.5.

Comparative Example 1.2 Preparation of Supports-6 and 7 Supports-6 and 7 were prepared in the same manner as Support-1 except that the following aqueous solution was used instead of the 1% sodium nitrite aqueous solution in the preparation of Support-1. I made it.

Support - 61% sodium sulfate aqueous solution Support - 71% barium acetate aqueous solution Preparation of photosensitive lithographic printing plate samples I-6 and 7 Photosensitive lithographic printing plate samples except that the supports 6 and 7 were used as supports. Photosensitive lithographic printing plate sample 1-6.7 was prepared in the same manner as I-1.

These samples were exposed and developed in the same manner as in the case of photosensitive planographic printing plate sample I-1 to obtain planographic printing plate samples I-6 and I-7.

Examples 6 to 10 A photosensitive composition coating solution (2) having the following composition was applied onto the support-1.
) was applied using a whirler and dried at 90°C for 1 minute.

The coating film thickness was 1.7 g/+*''. This was designated as photosensitive planographic printing plate sample 1f-1.

(Photosensitive composition coating liquid (2) composition) Copolymer *E5. Og Diazo resin *F O, 5g
Jurimer AC-1OL (manufactured by Nippon Tsumugi Co., Ltd.) 0
．． 05g Bikku Victoria Pure Blue B OH Togaya Chemical Co., Ltd.) 0.1g
Methyl cellosolve 100sI2
This sample was exposed to light using a 2kw metal halide lamp at g + * W/Cm'' for 60 seconds, and developed using a 6-fold dilution of commercially available developer 5DN-21 (manufactured by Konica Corporation). The development was carried out for 20 seconds at a developing temperature of 27° C. to obtain a lithographic printing plate sample n-1.

Preparation of Photosensitive Planographic Printing Plate Samples II-2, 3, 4, 5 The photosensitive composition coating solution (2) was applied onto the supports -2, 3, 4, and 5. A photosensitive lithographic printing plate sample ■-2°3.4.5 was prepared by coating in the same manner as in 1.

These samples were exposed and developed in the same manner as photosensitive lithographic printing plate sample 1 to obtain lithographic printing plate samples n-2, 3, 4, and 5.

Comparative Examples 3 and 4 The photosensitive composition coating liquid (2
) was applied in the same manner as the photosensitive lithographic printing plate sample n-t,
Photosensitive lithographic printing plate samples II-6 and 7 were prepared.

Regarding these samples, the photosensitive lithographic printing plate sample 11
Lithographic printing plate sample 1[-1] was exposed and developed in the same manner as -1.
I got 6,7.

*A Novolak resin phenol, 1-cresol, p-cresol, and formaldehyde copolycondensation resin (phenol-cresol and p-cresol in a molar ratio of 2.0:4.
8: 3.2, Mw=6500. Mv/Mn-5
, 4) *Bo-quinonediazide compound D ■ *C surfactant Emulgen 12o (manufactured by Kao Corporation) Polyoxyethyl lauryl ether *D Compound that generates halogen free radicals 2-Trichloromethyl-5-(p-methoxystyryl) )-1,3,4-
Oxadiazole (compound described in JP-A-54-74728 Example 1) *E Copolymer p-hydroxyphenyl methacrylamide/acrylonitrile/ethyl acrylate/methacrylic acid = to/
Copolymer with a composition of 30/60/6 Mv=60000 *F Diazo 1# Residual evaluation method Smear test due to residual fat 5 lines (5
■ Form an image area of mX 15c + m) and erase liquid (5
The image area was erased using IR-15 (manufactured by Konica Corp.). The erasing time was divided into 5 levels (shown in Table 1), and the 7-ring stains caused by the erasing at that time were checked by applying developing ink (5PO-1 manufactured by Konica Corp.).

O: Good △: Erased marks appear (ink does not adhere, but residual film is clearly visible).

×: Smudged (ink adheres to the surface).

Processing chemical resistance After plate making under the above exposure and development conditions, ink c 5pot for development ink application, manufactured by Konica Co., Ltd., P
(manufactured by Fuji Photo Film Co., Ltd.) and a plate cleaner (manufactured by LIPCA ABC Chemical Co., Ltd.) used during printing for a certain period of time, and the condition of the photosensitive layer on the plate at that time was evaluated.

0: No change.

△The surface of the nippet part is eroded.

×: The base part peels off.

Halftone reproducibility The lithographic printing plate obtained by the above method was used in a printing machine (Heidel GTO), coated paper printing ink (New Bright Red manufactured by Toyo Ink Manufacturing Co., Ltd.) and dipping water (5EU-
3, 2, 5%, manufactured by Konica Co., Ltd.) for printing. The halftone dot reproduction of the dark S (halftone dot area ratio: 97%) of the halftone dot image of the printed matter was evaluated using a 25x magnifying glass.

0: Reproduction (no entanglement).

×: Not reproduced (entangled).

Printing Durability Printing under the above conditions was continued until poor inking appeared in the solid area of the image area of the printed matter or ink was adhered to the non-image area, and the number of printed sheets at that time was counted.

Below are blank spaces Examples 11 to 20 Preparation of support -1° to 5° The following aqueous solution was used in place of the 1% sodium nitrite aqueous solution in the preparation of support -1; otherwise the procedure was the same as support -1. Supports 1' to 5' were prepared.

Support - 1'0.5% sodium nitrite aqueous solution support -
2″ 0.5% potassium nitrite solution support -3° 0.
5% calcium nitrite aqueous solution support -4° 0.5% ammonium nitrite aqueous solution support -5' 0.5% nickel nitrite aqueous solution support -1 Except for using the supports shown in Table 3, photosensitive Photosensitive lithographic printing plate samples I [[-1 to lll-5] were prepared in the same manner as photosensitive lithographic printing plate sample 1-1. In addition, photosensitive planographic printing plates IT/-1 to Vl-5 were prepared in the same manner as photosensitive planographic printing plate sample 11-1 except for using the support shown in Table 4 instead of support-1. .

These photosensitive lithographic printing plate samples were exposed and developed in the same manner as in Example 1 to obtain lithographic printing plate sample 1.
11-1 to DI-5 and IV-1 to Vl-5 From the above experimental results, the photosensitive lithographic printing plates according to the present invention have lower staining due to residual film from development processing and printing durability than those made using conventional techniques. It can be seen that both are excellent.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a photosensitive lithographic printing plate which is excellent in both the occurrence of stains due to residual film and printing durability.

Claims (1)

[Scope of Claims] 1) A photosensitive lithographic printing plate, characterized in that the surface of a pretreated support is treated with an aqueous solution containing nitrous acid or nitrite, and then a photosensitive layer is provided on the surface. 2) The photosensitive lithographic printing plate according to claim 1, wherein the nitrite is a metal salt or an ammonium salt.