JP2967009B2 - Photosensitive lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate, and more particularly, to a photosensitive lithographic printing plate having an aluminum support provided with an anodized film on its back surface and a back coat layer provided on the anodized film. .

[0002]

2. Description of the Related Art Conventionally, a positive photosensitive lithographic printing plate widely used has a photosensitive layer comprising an o-quinonediazide compound provided on an aluminum plate as a support. It is known that an o-quinonediazide compound changes to a carboxylic acid upon exposure to ultraviolet light,
Therefore, when this is developed with an alkaline aqueous solution, only the exposed portions of the photosensitive layer are removed, and the surface of the support is exposed. Since the surface of the aluminum support is hydrophilic, a portion (non-image portion) where the surface of the support is exposed by development retains water and repels oil-based ink. On the other hand, the area (image area) where the photosensitive layer has not been removed by development is lipophilic and repels water to receive ink. On the other hand, as a negative photosensitive lithographic printing plate, a photosensitive layer comprising a photosensitive diazonium salt on a support,
It is known to provide a photosensitive layer made of a photopolymerizable monomer and a photocrosslinkable photosensitive layer made of a polymer compound containing a cinnamic acid or a dimethylmaleimide group. In these photosensitive layers, the exposed portions are cured, and only the unexposed portions are removed by a suitable developing solution, and are similarly used as a lithographic printing plate.

A large number of these photosensitive lithographic printing plates (PS plates) are transported in piles, but in this case, there is a problem that the PS plates are rubbed and the photosensitive layer is damaged. In order to solve this problem, it has been common practice to insert a sandwich paper called a slip sheet for each PS plate when laminating the PS plates. However, when the PS plate is used in a large amount, a large amount of interleaf paper is discharged as industrial waste, which is a resource protection or environmental problem. Therefore, various methods have been proposed as methods that do not use interleaving paper. For example, Japanese Patent Application Laid-Open No. 50-1511
No. 36 discloses a method in which a back coat layer made of a polymer is provided on the back surface of a support, and the aluminum surface on the back surface of the support is not brought into direct contact with the photosensitive layer of the PS plate superposed thereunder. Another purpose of providing a back coat layer on the back surface of the support is that the aluminum surface on the back surface does not come into direct contact with the developer. This has the following effects. That is, an aqueous solution of an alkali metal silicate is often used as a developer for the negative or positive photosensitive lithographic printing plate. However, since the aqueous solution is generally strongly basic having a pH of 12 or more. , Dissolve the aluminum. It is known that this aluminum dissolved in a strong basic aqueous solution reacts with silicic acid in a developer, gradually becomes insoluble, and precipitates. This insoluble matter causes problems such as adhering to the PS plate, clogging the nozzle of the automatic processor, and clogging the filter. The problem is that by providing a back coat layer on the back of the aluminum support to prevent direct contact with the developer,
Almost eliminated.

It is well known that the provision of the back coat layer on the back surface of aluminum as described above can prevent abrasion of the photosensitive layer and generation of insoluble matters when a large number of PS plates are transported in a pile. It is. However, since the aluminum back surface and the back coat layer usually have poor adhesion, if a large number of PS plates having a back coat layer are stored and stored on the back surface of the support, the photosensitive layer or the interleaf paper will be formed due to the load. There was a problem that the back coat layer of the PS plate laminated thereon adhered, and the back coat layer was peeled off from the back surface of the support. Also, when a large number of PS plates are stacked and transported, the adhesion between the back surface of the support and the back coat layer is insufficient, so that the back coat layer may be rubbed or partially peeled off. However, there has been a problem that the photosensitive layer of the PS plate overlaid on the substrate is damaged. In particular, peeling and scratching when using multiple sheets without interleaving paper or when using pure pulp paper that is not laminated with polyethylene, etc., which has recently become a problem in terms of recycling, when used as interleaving paper there were. Furthermore, during the development process, peeling may occur due to poor adhesion between the back surface of the support and the back coat layer, and aluminum may be eluted from the back surface of the support to form an insoluble matter. For this reason, a PS plate having a back coat layer has not been put to practical use at present.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the adhesiveness between a support and a back coat layer, and to prevent the back coat layer from peeling off even when a large number of sheets are stored or transported. Another object of the present invention is to provide a photosensitive lithographic printing plate in which no insoluble matter is generated in a developing solution even when a large amount of developing treatment is performed with a developing solution comprising an alkali metal silicate. Another object of the present invention is to provide a lithographic printing plate which does not suffer from abrasion even when interleaving paper which is an industrial waste is removed.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that the average pore density on the back surface of the aluminum support is 7.0 × 10 ^{10 to} 1.0 ×. 10
^By providing an anodic oxide film having ¹² pores / cm ² and an average pore diameter of 50 to 300 ° in an amount of 0.2 to 2.0 g / m ² ,
The back surface of the aluminum support has a very high adhesion to the back coat layer, and as a result,
The inventor has found that the backcoat layer does not peel off from the support, and has completed the present invention based on this finding. That is, the present invention provides a photosensitive lithographic printing plate in which a photosensitive layer is provided on the surface of an aluminum support, and a back coat layer is provided on the back surface of the support, and the average pore density is 7.0 × 10 ¹⁰ to 1. An anodic oxide film having a pore size of at least 0 × 10 ¹² / cm ² and an average pore diameter of 50 to 300 ° is used.
The present invention relates to a photosensitive lithographic printing plate provided in an amount of ^{2 to} 2.0 g / m ² . Hereinafter, the present invention will be described in detail.

The support used in the PS plate of the present invention is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon,
Examples include iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is at most 10% by weight or less. Aluminum suitable for the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and a conventionally known and used material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to about 0.6 mm.

[0008] An anodic oxide film is provided on the back surface of the aluminum plate in order to improve the adhesion to the back coat layer. The average pore density of this anodized film is 7 × 10
^{10 to} 1.0 × 10 ¹² / cm ² , preferably 1.0 × 1
0 ^{11 to} 1.0 × 10 ¹² / cm ² . 7 × 10 ¹⁰ pieces / cm
^{If the} average pore density is smaller than ² , the adhesion between the anodic oxide film and the back coat layer is reduced, and it is practically difficult to form a film having an average pore density higher than 1.0 × 10 ¹² / cm ² . The average pore diameter of the anodic oxide film is 50 to 300 °. As the pore average diameter is larger than 300 °, the adhesion is improved, but it is difficult to actually produce an anodic oxide film having a pore average diameter larger than 300 °. On the other hand, 50Å
If it is smaller, the adhesion will be poor. The amount of the anodic oxide film is 0.2 to 2.0 g / m ² . If the amount is less than 0.2 g / m ² , the adhesion will be reduced, and if the amount is more than 2.0 g / m ² , the effect of substantially increasing the amount will be small, and the cost will increase due to the amount of electricity used. Connect.

The anodic oxidation for forming such an anodic oxide film is performed, for example, with sulfuric acid, phosphoric acid, oxalic acid, chromic acid or a mixed acid thereof. Among them, sulfuric acid is preferable as the electrolyte. The concentration of the electrolyte varies depending on the type of electrolyte used, but is generally from 10 to 45% by weight. Unless otherwise specified, concentrations as high as possible in this range are preferred. The temperature of the electrolyte is generally 25 to 70 ° C. Unless otherwise indicated, the highest possible temperature is preferred. The current density is generally between ² and 20 A / dm ² . Unless otherwise indicated, the lowest possible current density is preferred. The voltage is generally between 10 and 50V. Unless otherwise noted,
The lowest possible voltage is preferred. Electrolysis time is generally 0.5
~ 180 seconds. As long as there is no other problem, the longest possible time is preferable.

[0010]

[Backcoat layer] A backcoat layer is provided on the back surface of the aluminum support used in the present invention. As a material of the back coat layer, an organic or inorganic polymer compound insoluble in an alkaline silicate developer is used, for example, polyethylene, polypropylene, polybutene, polybutadiene, nylon, polyester, polyurethane, polyurea, polyimide, polysiloxane. , Polycarbonate, phenoxy resin, epoxy resin, aldehyde condensation resin of alkylphenol, polyvinyl acetal resin,
Polyvinyl chloride, polyvinylidene chloride, polystyrene,
Acrylic resins and copolymer resins thereof are suitable. Other suitable backcoat layer materials include copolymers having a molecular weight of usually 10,000 to 200,000, containing monomers shown in the following (1) to (12) as constituent units. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, for example, N- (4-
(Hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) methacrylamide, o-, m- and p-hydroxystyrene, o-, m- and p-hydroxyphenyl acrylate or methacrylate, (2) acrylic having an aliphatic hydroxyl group Acid esters and methacrylic esters, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate,

(3) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, acrylic acid-2 (Substituted) acrylates such as -chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, (4) methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate, (Substituted) methacrylates such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate, (5) acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N- Hexylacrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N
-Hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N
-Phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N
Acrylamide or methacrylamide such as -ethyl-N-phenylmethacrylamide,

(6) ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether; (7) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate; (8) styrenes such as styrene, methyl styrene and chloromethyl styrene; 9)
Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (10) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene;

(11) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like, (12) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) ) Acrylamide, N- (p-
Aminosulfonylphenyl) acrylamide, N- [1
Acrylamides such as-(3-aminosulfonyl) naphthyl] acrylamide, N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1-
(3-aminosulfonyl) naphthyl] methacrylamide, methacrylamides such as N- (2-aminosulfonylethyl) methacrylamide, o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, 1 -(3-aminosulfonylphenylnaphthyl)
Unsaturated sulfonamides such as acrylates such as acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, 1
Unsaturated sulfonamides such as methacrylic esters such as-(3-aminosulfonylphenylnaphthyl) methacrylate;

Further, a monomer copolymerizable with the above monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers may be modified with, for example, glycidyl acrylate, glycidyl methacrylate, or the like, but is not limited thereto. Further, as the back coat layer, a resin back coat layer obtained by providing a composition curable by light and / or heat on the back surface of the support and then curing the composition is rich in alkali developer resistance. Particularly preferred. Such light and / or
Or, as the thermosetting composition, a photopolymerizable composition, a composition comprising a diazo resin, a composition comprising a photosensitive azide compound, a photocrosslinkable composition, a thermopolymerizable composition, and a thermocrosslinkable composition. Can be

A ) Photopolymerizable Composition The photopolymerizable composition used in the back coat layer includes:
It contains a polymer binder, an unsaturated monomer having at least one addition-polymerizable unsaturated bond, and a photopolymerization initiator.
Binders for the photopolymerizable composition include polyvinyl butyral, polyvinyl acetate, polyvinyl pyrrolidone, gelatin, coumarone indene resin, silicone resin, rubber, etc. as disclosed in JP-B-38-9663. JP-A No. 49-123021, such as vinylidene chloride copolymer, cellulose ether, synthetic rubber, polyvinyl acetate copolymer, polyacrylate, polyvinyl chloride, etc. It is a chlorinated polyolefin. Examples of the unsaturated monomer having at least one addition-polymerizable unsaturated bond group include (meth) acrylates, (meth) acrylamides, allyl compounds, vinyl ethers, vinyl esters, and N-vinyl. Compounds, styrenes, crotonic esters and the like. Two or more monomers having such an addition-polymerizable unsaturated bond can be used in combination. These monomers are used in an amount of 1 to 100 parts by weight of the polymer binder.
It is used in an amount of 0 to 500 parts by weight, preferably 30 to 200 parts by weight. On the other hand, as the photopolymerization initiator used in the present invention, conventionally known photopolymerization initiators can be suitably used. Examples include carbonyl compounds, organic sulfur compounds, peroxides, redox compounds, azo and diazo compounds, halogen compounds, photoreducible dyes and the like as described in Chapter 5 of "Light-Sensitive Systems" by Coser. As typical specific examples, as the carbonyl compound, for example, benzoin, benzoin methyl ether, benzophenone, anthraquinone,
9,10-anthraquinone, 2-methylanthraquinone, 2-tert-butyl-anthraquinone, 9,10-phenanthrenequinone, diacetyl, benzyl and the like are useful.

These photopolymerization initiators include unsaturated monomer 1
It is used in the range of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight. It is preferable to further add a thermal polymerization inhibitor to the photopolymerizable composition used in the present invention. Specific examples of the thermal polymerization inhibitor include, for example, paramethoxyphenol, hydroquinone, alkyl or aryl-substituted hydroquinone,
t-butylcatechol, pyrogallol, cuprous chloride, phenothiazine, chloranil, naphthylamine, α-naphthol, 2,6-di-t-butyl-p-cresol,
Examples include pyridine, nitrobenzene, dinitrobenzene, p-toluidine, and copper methylene blue organic acid (eg, copper acetate). These thermal polymerization inhibitors are preferably contained in the range of 0.001 to 5 parts by weight based on 100 parts by weight of the unsaturated monomer.

The photopolymerizable composition used in the present invention may further contain various additives such as a coloring agent, a plasticizer and a resin. Examples of the coloring agent include pigments such as titanium oxide, carbon black, iron oxide, phthalocyanine pigments and azo pigments, and dyes such as methylene blue, crystal violet, rhodamine B, fuchsin, auramine, azo dyes and anthraquinone dyes. However, it is preferable that the coloring agent used does not absorb the light having the absorption wavelength of the photopolymerization initiator. Such a colorant is used in an amount of 0.1 to 30 parts by weight in the case of a pigment and 0.01 to 10 parts by weight, preferably 0.1 in the case of a dye, based on 100 parts by weight of the total amount of the polymer binder and the unsaturated monomer. It is preferred that the content be contained in the range of 3 to 3 parts by weight.

B) Composition Containing Diazo Resin The diazo resin represented by a condensate of p-diazodiphenylamine and paraformaldehyde may be a water-soluble or water-insoluble resin, but is preferably a water-insoluble or water-insoluble resin. Those soluble in ordinary organic solvents are used. Particularly preferred diazo compounds include salts of condensates of p-diazodiphenylamine with formaldehyde or acetaldehyde, such as phenol salts, fluorocaprates, and triisopropylnaphthalenesulfonic acid,
4-biphenyldisulfonic acid, 5-nitroortho-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-chloro -5-nitrobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, 1
-Having two or more diazo groups in one molecule, such as salts of sulfonic acids such as naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid and paratoluenesulfonic acid; Compound. Other preferred diazo resins include the condensates of 2,5-dimethoxy-4-p-tolylmercaptobenzenediazonium and formaldehyde containing the above salts,
Condensates of dimethoxy-4-morpholinobenzenediazonium with formaldehyde or acetaldehyde are included. Further, diazo resins described in GB 1,312,925 are also preferred.

The diazo resin alone can be a photosensitive substance used for forming a coating layer, but is preferably used together with a binder. As such a binder, various polymer compounds may be used, and hydroxy, amino,
Carboxylic acids, amides, sulfonamides, active methylene,
Those containing groups such as thioalcohol and epoxy are preferred. Such preferred binders include British Patent No. 1,
Polymers containing a hydroxyethyl acrylate unit or a hydroxyethyl methacrylate unit as a main repeating unit, as described in US Pat.Nos. 4,460,978 and 4,123,276. U.S. Pat.No. 3,751,257
No. 1, the polyamide resin described in
No. 074,392 and phenolic resins and polyvinyl acetal resins such as polyvinyl formal resins, polyvinyl butyral resins, U.S. Pat.
No. 3,660,097, the linear polyurethane resin described in JP-A-62-123452, the polyurethane having an alkali-soluble group described in JP-A-62-123452, and JP-A-62-16.
No. 9154, a polyvinyl acetal resin having an alkali-soluble group, a phthalated resin of polyvinyl alcohol, an epoxy resin condensed from bisphenol A and ebichlorohydrin, and polyaminostyrene and polyalkylamino (meth) acrylate. Examples include polymers containing an amino group, celluloses such as cellulose acetate, cellulose alkyl ether, cellulose acetate phthalate, and the like.

The content of the binder is suitably from 40 to 95% by weight in the back coat layer. When the amount of the binder increases (that is, when the amount of the diazo resin decreases), the photosensitivity naturally increases. The optimal amount of binder is about 70-90% by weight. Additives such as phosphoric acid, dyes and pigments described in U.S. Pat. No. 3,236,646 can be further added to the composition comprising a diazo resin.

C) Compositions comprising a photosensitive azide compound Suitable photosensitive azide compounds are aromatic azide compounds in which the azide group is linked to the aromatic ring either directly or via a carbonyl or sulfonyl group. In these, azide groups are decomposed by light to produce nitrene, and nitrene undergoes various reactions to be insolubilized. Preferred aromatic azide compounds are compounds containing one or more groups such as azidophenyl, azidostyryl, azidobenzal, azidobenzoyl and azidocinnamoyl. These photosensitive azide compounds are preferably used together with a polymer compound as a binder. Preferred binders include alkali-soluble resins, for example, natural resins such as shellac and rosin, for example, novolak phenol resins such as phenol formaldehyde resin and m-cresol formaldehyde resin, for example, polyacrylic acid, polymethacrylic acid, and methacrylic acid-styrene. Unsaturated carboxylic acid homopolymer such as polymer, methacrylic acid-methyl acrylate copolymer, styrene-maleic anhydride copolymer or copolymer thereof with another copolymerizable monomer, polyvinyl acetate Partially or completely saponified, for example, acetaldehyde, benzaldehyde,
Examples include resins partially acetalized with aldehydes such as hydroxybenzaldehyde and carboxybenzaldehyde, and polyhydroxystyrene. Further, organic solvent-soluble resins such as cellulose alkyl ethers such as cellulose methyl ether and cellulose ethyl ether can be used as the binder.

Preferably, the binder is contained in the range of about 10% to about 90% by weight based on the total weight of the composition comprising the photosensitive azide compound. The composition comprising the photosensitive azide compound further contains a dye, a pigment, a plasticizer, a Michler's ketone, 9-fluorenone, 1-nitropyrene, 1,8-dinitropyrene, 2-chloro-1,2-benzanthraquinone, 2-bromo-1,2-benzanthraquinone, pyrene-1,6-quinone, 2-chloro-
Additives such as sensitizers such as 1,8-phthaloylnaphthalene and cyanoacridine can be added.

D) -CH = CH- as a photosensitive group on the main chain or side chain of the photocrosslinkable composition polymer
Those based on photosensitive polymers such as CO-containing polyesters, polyamides and polycarbonates (for example, those described in U.S. Pat. Nos. 3,030,208, 3,707,373 and 3,453,237). Compounds based on (2-propenylidene) malonic acid compounds such as cinnamylidenemalonic acid and photosensitive polyesters derived from difunctional glycols (see, for example, US Pat. Nos. 2,956,878 and No. 3,173,787); cinnamic esters of hydroxyl-containing polymers such as polyvinyl alcohol, starch, cellulose and the like (eg, US Pat. No. 2,690,966). Nos. 2,752,372 and 2
732,301 etc.) and the like. These compositions may further contain sensitizers, stabilizers, plasticizers, pigments, dyes, and the like.

E) Thermopolymerizable and thermocrosslinkable composition As the thermopolymerizable composition, for example, a composition obtained by adding a thermal polymerization initiator such as a peroxide to the aforementioned photopolymerizable composition,
A composition comprising an azide compound that can be decomposed and crosslinked by heat is used. Both light and heat can optionally be used to cure these compositions. Further, a thermosetting composition containing an isocyanate compound or an epoxy group can also be preferably used. Further, as the back coat layer, a coating layer composed of a metal compound obtained by hydrolysis and polycondensation of an organic metal compound or an inorganic metal compound described in Japanese Patent Application No. 4-189448 may be used. Examples of the metal oxide used for such a back coat layer include silica (silicon oxide), titanium oxide, boron oxide, aluminum oxide, zirconium oxide, and a composite thereof. The coating layer of the metal oxide used in the present invention is a so-called sol-gel obtained by hydrolyzing an organometallic compound or an inorganic metal compound in water and an organic solvent with a catalyst such as an acid or an alkali, and causing a condensation polymerization reaction.
It is obtained by applying and drying the gel reaction solution on the back surface of the support. Examples of the organometallic compound or inorganic metal compound used herein include metal alkoxide, metal acetylacetonate, metal acetate, metal oxalate, metal nitrate, metal sulfate, metal carbonate, metal oxychloride, and metal chloride. And condensates obtained by partially hydrolyzing and oligomerizing them.

These organometallic compounds or inorganic metal compounds can be used alone or in combination of two or more. Among these organometallic compounds or inorganic metal compounds, metal alkoxides are preferable because they have high reactivity and easily produce a polymer formed from a metal-oxygen bond. Among them, Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (O
Alkoxy compounds of silicon, such as C ₃ H ₇ ) ₄ and Si (OC ₄ H ₉ ) ₄ , are inexpensive and readily available, and the metal oxide coating layer obtained therefrom is particularly preferred because of its excellent developer resistance. Oligomers obtained by partially hydrolyzing and condensing these silicon alkoxy compounds are also preferable. An example of this is an average pentameric ethyl silicate oligomer containing about 40% by weight SiO ₂ . Further, it is also preferable to use a so-called silane coupling agent in which one or two alkoxy groups of the above silicon tetraalkoxy compound are substituted with an alkyl group or a reactive group.

In order to start the sol-gel reaction, an appropriate amount of water is further required, and the preferable addition amount is 0.05 to 5 times the amount of water required to completely hydrolyze the starting metal compound.
The molar ratio is preferably 50-fold, more preferably 0.5 to 30-fold. If the amount of water is less than this range, the hydrolysis does not easily proceed, and if it is more than this range, the reaction is difficult to proceed, probably because the raw materials are diluted. A solvent is further added to the sol-gel reaction solution. The solvent may be any as long as it dissolves the metal compound of the raw material and dissolves or disperses the sol-gel particles generated by the reaction.Methanol, ethanol, propanol, lower alcohols such as butanol, acetone,
Ketones such as methyl ethyl ketone and diethyl ketone are used. In addition, ethylene glycol, diethylene glycol, and the like for the purpose of improving the coating surface quality of the back coat layer, etc.
Mono or dialkyl ethers and acetates of glycols such as triethylene glycol, propylene glycol and dipropylene glycol can be used. Among these solvents, lower alcohols that can be mixed with water are preferred. The sol-gel reaction solution is prepared with a solvent at a concentration suitable for application. However, if the entire amount of the solvent is added to the reaction solution from the beginning, the raw material will be diluted, or the hydrolysis reaction will not proceed easily. Therefore, it is preferable to add a part of the solvent to the sol-gel reaction liquid and add the remaining solvent when the reaction has progressed.

The sol-gel reaction proceeds by mixing a metal oxide raw material, water, a solvent and a catalyst. The progress of the reaction depends on their type, composition ratio, reaction temperature and time, and also affects the film quality after film formation. Since the influence of the reaction temperature is particularly large, it is preferable to control the temperature during the reaction. A plasticizer or a surfactant may be further added to the back coat layer for the purpose of imparting flexibility or improving the slipperiness and the coated surface state. Preferred surfactants include anionic,
Cationic, nonionic and amphoteric surfactants are included.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid partial esters. , Sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester , Polyoxyethylenated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, and trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkylbenzene sulfonates, branched alkylbenzene sulfonates,

Alkyl naphthalene sulfonates, alkyl phenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salts, petroleum Sulfonates, sulfated castor oil, sulfated tallow oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates , Polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ethers phosphates , Polyoxyethylene alkylphenyl ether phosphate salts, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, naphthalene sulfonate formalin condensates, etc. Anionic surfactants, alkylamine salts, quaternary ammonium salts,
Examples include cationic surfactants such as polyoxyethylene alkylamine salts and polyethylene polyamine derivatives, and amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the surfactants mentioned above, the term "polyoxyethylene" can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, or polyoxybutylene, and these surfactants are also included. More preferred surfactants are fluorine-based surfactants containing a perfluoroalkyl group in the molecule.

Examples of the fluorine-based surfactant include an anionic type such as perfluoroalkyl carboxylate, perfluoroalkyl sulfonate and perfluoroalkyl phosphate, an amphoteric type such as perfluoroalkyl betaine, and perfluoroalkyltrimethyl. Cationic and perfluoroalkylamine oxides such as ammonium salts, perfluoroalkylethylene oxide adducts, oligomers containing perfluoroalkyl groups and hydrophilic groups, oligomers containing perfluoroalkyl groups and lipophilic groups, perfluoroalkyl groups, hydrophilic groups and Non-ionic types such as lipophilic group-containing oligomers, perfluoroalkyl groups and lipophilic group-containing urethanes are included. Further, fluorine surfactants described in JP-A Nos. 62-170950, 62-226143 and 60-168144 are also preferably used.

The above surfactants can be used alone or in combination of two or more, and are contained in the back coat layer in an amount of from 0.001% by weight to about 10% by weight, more preferably from 10% by weight.
It is used in the range from 0.01% by weight to 1% by weight. Preferred plasticizers include, for example, phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, and diallyl phthalate; Glycol esters such as dimethyl glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate, and phosphate esters such as tricresyl phosphate and triphenyl phosphate , Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, di Chirusebaketo, dioctyl azelate,
Aliphatic dibasic acid esters such as dibutyl maleate,
Polyglycimyl methacrylate, triethyl citrate,
Glycerin triacetyl ester, butyl laurate and the like are effective. Plasticizers are generally used in amounts up to about 30% by weight, based on the total weight of the resin used in the backcoat layer.

The thickness of the back coat layer is such that the elution of the anodic oxide film of aluminum during development is suppressed and the photosensitive layer is hardly damaged even without interleaving paper, and is generally 0.01 to 50 g / dry film thickness. m ² , preferably 0.01 to 8.0 g
/ M ² . When the thickness exceeds 50 g / m ² , during printing, the back coat layer swells due to chemicals used around the printing, the thickness fluctuates, the printing pressure changes, and the printing characteristics deteriorate. The effect of the anodic oxide film in the present invention is more remarkably exhibited as the back coat layer is thinner.

Various methods can be applied as a method of coating the back coat layer on the back surface of the aluminum support. For example, a back coat layer substantially composed of an organic polymer compound, a solution of the above components in a suitable solvent, or a method of applying and drying an emulsified dispersion, for example, a method in which the components are preliminarily formed into a film. A method of bonding to a support with an adhesive or heat, a method of forming a molten film with a melt extruder, and bonding to a support, and the like are mentioned. , And apply the solution to the surface of the support, followed by drying. Further, the back coat layer substantially consisting of a cured product of the light and / or thermosetting composition is prepared by preparing the light and / or thermosetting composition, and forming a solution in a solvent-free or appropriate solvent, or A method of applying an emulsified dispersion to a support and drying it, for example, a method in which a preformed film is bonded to the support with an adhesive or heat and a melt extruder to form a molten film, and the support is formed on the support. Although a method of bonding and the like can be mentioned, the most preferable method for securing the above-mentioned coating amount is a method of coating and drying without using a solvent or a solution. The back coat layer provided in this manner is cured by actinic rays and / or heat.

Examples of the solvent for the coating solution for the back coat layer include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and diisobutyl ketone, for example, ethyl acetate, butyl acetate, and the like.
N-amyl acetate, methyl formate, ethyl propionate,
Esters such as dimethyl phthalate and ethyl benzoate; aromatic hydrocarbons such as toluene, xylene, benzene, and ethylbenzene; carbon tetrachloride, trichloroethylene, chloroform, 1,1,1-trichloroethane, methylene dichloride, ethylene Halogenated hydrocarbons such as dichloride, monochlorobenzene, chloronaphthalene, etc., methanol, ethanol, n-
Aliphatic alcohols such as propanol, isopropanol, n-butanol and tert-butanol, for example, tetrahydrofuran, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, etc. Glycol ethers and esters thereof, dimethylformamide, dimethylsulfoxide and the like can be used alone or in combination. Next, the surface of the aluminum plate on which the photosensitive layer is provided, that is, the surface will be described.

The surface of the aluminum plate is preferably roughened. If desired, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution may be performed before the surface roughening to remove the rolling oil on the surface. Roughening of the aluminum plate surface can be achieved by mechanically roughening the surface,
There are a method of electrochemically dissolving and roughening the surface and a method of chemically selectively dissolving the surface. As a mechanical method,
Known methods called a ball polishing method, a brush polishing method, a blast polishing method, a buff polishing method, and the like can be used. In addition, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Also,
As disclosed in JP-A-54-63902, a method in which both are combined can also be used. The roughened aluminum plate is subjected to an alkali etching treatment and a neutralization treatment, if necessary, and then subjected to an anodic oxidation treatment, if necessary, to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte that forms a porous oxide film can be used, and generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. . The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The anodizing treatment conditions vary depending on the electrolyte to be used, and thus cannot be specified unconditionally. It is appropriate that the voltage is 60 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 10 seconds to 5 minutes. In the sulfuric acid method, the treatment is usually performed with a direct current, but an alternating current can also be used. The concentration of sulfuric acid is used in 5-30%, and 20-6
The electrolytic treatment is performed in a temperature range of 0 ° C. for 5 to 250 seconds. This electrolyte preferably contains aluminum ions. The current density at this time is preferably 1 to 20 A / dm ² . In the case of the phosphoric acid method, a concentration of 5 to 50%, 30 to
At a temperature of 60 ° C., 1 to 15 A / dm ² for 10 to 300 seconds.
Of the current density. The amount of anodized film is 1.0 g /
m ² or more is preferred, but more preferably 2.0 to 6.0 g /
m ² . If the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image area of the lithographic printing plate is easily scratched, and the ink adheres to the scratched area during printing. "Scratch dirt" easily occurs.

In order to simplify the production process of the support used in the present invention, it is preferable to carry out the positive oxidation on the back surface and the positive oxidation on the front surface simultaneously in the same step.
The surface of the anodized aluminum support is subjected to a hydrophilic treatment as necessary. U.S. Pat.Nos. 2,714,066 and 3,18 as hydrophilic treatments used in the present invention.
There is an alkali metal silicate (for example, sodium silicate aqueous solution) method as disclosed in 1,461, 3,280,734 and 3,902,734. In this method, the support is immersed or electrolytically treated in an aqueous solution of sodium silicate. Other methods include treatment with potassium fluorozirconate disclosed in JP-B-36-22063 and polyvinylphosphonic acid as disclosed in U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689,272. Used.

[0038]

[Organic undercoat layer] The surface of the aluminum plate treated as described above may be provided with an organic undercoat layer, if necessary, before coating the photosensitive layer. Examples of the organic compound used in the organic undercoat layer include carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, and naphthyl. Organic phosphonic acids such as phosphonic acids, alkyl phosphonic acid glycerophosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid,
Organic phosphoric acids such as phenylphosphoric acid, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid which may have a substituent, phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent Such as organic phosphinic acid, glycine and β-
It is selected from amino acids such as alanine, and hydrochlorides of amines having a hydroxyl group such as hydrochloride of triethanolamine, but may be used in combination of two or more.

This organic undercoat layer can be provided by the following method. That is, water or methanol, ethanol,
A method in which a solution obtained by dissolving the above organic compound in an organic solvent such as methyl ethyl ketone or a mixed solvent thereof is applied to the surface of an aluminum plate and dried, or water or an organic solvent such as methanol, ethanol, methyl ethyl ketone or a mixture thereof. There is a method in which an aluminum plate is immersed in a solution obtained by dissolving the organic compound in a solvent to adsorb the organic compound, and then washed with water or the like and dried to provide an organic undercoat layer. In the former method,
Solutions of the above organic compounds having a concentration of 0.005 to 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and the immersion temperature is 20 to 90C, preferably 25 to 90%.
The temperature is 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. Such a solution may be a basic substance such as ammonia, triethylamine, potassium hydroxide,
The pH is adjusted with acidic substances such as hydrochloric acid and phosphoric acid,
Twelve ranges can also be used. Further, a yellow dye can be added for improving the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer after drying is 2 to 20.
0 mg / m ² is suitable, preferably 5 to 100 mg / m ^2
2 If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

[0040]

Photosensitive layer On the surface of the thus obtained aluminum plate having a hydrophilic surface, a photosensitive layer made of a known photosensitive composition is provided to obtain a photosensitive lithographic printing plate. As the photosensitive composition, o-quinonediazide compound as a main component, a diazonium salt, an alkali-soluble diazonium salt, a photopolymerizable compound having an unsaturated double bond-containing monomer as a main component, and cinnamic acid and dimethylmaleimide Negative type photo-crosslinkable compounds containing a group as a photosensitive composition are used.

[0041]

[Positive photosensitive layer] Among these, o-naphthoquinonediazide compounds used as positive photosensitive compositions include:
1, 2 described in JP-B-43-28403.
-Esters of diazonaphthoquinonesulfonic acid with pyrogallol-acetone resin are preferred. Other suitable orthoquinonediazide compounds include, for example, U.S. Pat.
3,046,120 and 3,188,210, there is an ester of 1,2-diazonaphthoquinone-5-sulfonic acid and phenol-formaldehyde resin described in the specification,
There are esters of 1,2-diazonaphthoquinone-4-sulfonic acid and phenol-formaldehyde resin described in JP-A-2-96163, JP-A-2-96165 and JP-A-2-96661. Other useful o-naphthoquinonediazide compounds include
Examples include those known in numerous patents and the like. For example, JP-A Nos. 47-5303, 48-63802, 48
-63803, 48-96575, 49-38
Nos. 701, 48-13854, and JP-B-37-180
No. 15, No. 41-11222, No. 45-9610,
No. 49-17481, U.S. Pat.No. 2,797,213,
No. 3,454,400, No. 3,544,323, No. 3,573,917
No. 3,674,495, No. 3,785,825, UK Patent No.
No. 1,227,602, No. 1,251,345, No. 1,267,005,
Nos. 1,329,888 and 1,330,932, German Patent No. 8
Examples thereof include those described in each specification such as 54,890.

The o-naphthoquinonediazide compound particularly preferred in the present invention is a compound obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid. Specific examples of such compounds are described in JP-A-51-139402 and JP-A-58-139402.
-150948, 58-203434, 59-
165053, 60-12445, 60-1
No. 34235, No. 60-163430, No. 61-11
No. 8744, No. 62-10645, No. 62-1064
No. 6, 62-153950, 62-178562
No. 64-76047, U.S. Pat.No. 3,102,809,
No. 3,126,281, No. 3,130,047, No. 3,148,983
No. 3,184,310, No. 3,188,210, No. 4,63
Examples described in each gazette or specification such as 9,406 can be mentioned.

When synthesizing these o-naphthoquinonediazide compounds, it is preferable to react 0.2-1.2 equivalents of 1,2-diazonaphthoquinonesulfonic acid chloride with respect to the hydroxyl group of the polyhydroxy compound. .3
More preferably, the reaction is carried out in an amount of up to 1.0 equivalent. 1,2-diazonaphthoquinone sulfonic acid chloride includes 1,2
-Diazonaphthoquinone-5-sulfonic acid chloride or 1,2-diazonaphthoquinone-4-sulfonic acid chloride can be used. The obtained o-naphthoquinonediazide compound is a mixture of various compounds having different positions and amounts of 1,2-diazonaphthoquinonesulfonic acid ester groups. The compound is
The proportion occupying in this mixture (the content of the completely esterified compound) is preferably at least 5 mol%,
More preferably, it is 20 to 99 mol%.

The amount of these positive-acting photosensitive compounds (including the above combinations) in the photosensitive layer of the present invention is suitably from 10 to 50% by weight, more preferably from 1 to 50% by weight.
5 to 40% by weight. The o-quinonediazide compound alone can constitute the photosensitive layer, but it is preferable to use a resin soluble in alkaline water as a binder. Such resins soluble in alkaline water include novolak resins, such as phenol formaldehyde resins, o-, m- and p-cresol formaldehyde resins, m / p-mixed cresol formaldehyde resins, phenol / cresol ( o-, m-, p
, M / p- and o / m-mixtures). Also, phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, JP-A-51-3471.
Acrylic resins containing a phenolic hydroxyl group as disclosed in JP-A-1 can also be used. Other suitable binders include copolymers having the following (1) to (13) monomers as structural units and usually having a molecular weight of 10,000 to 200,000.

(1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having an aromatic hydroxyl group, such as N- (4-hydroxyphenyl) acrylamide or N- (4-hydroxyphenyl) ) Methacrylamide, o
-, M- and p-hydroxystyrene, o-, m- and p-hydroxyphenyl acrylate or methacrylate, (2) acrylates and methacrylates having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate,

(3) unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and methaconic acid;
Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, acrylic acid 4 (Substituted) acrylates such as -hydroxybutyl, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate, glycidyl methacrylate, N -(Substituted) methacrylates such as dimethylaminoethyl methacrylate,

(6) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide, N-hexyl acrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N
-Hydroxyethylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N
Acrylamides such as -phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide Or methacrylamide,

(7) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether; (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate; (9) styrenes such as styrene, methyl styrene and chloromethyl styrene; 1
0) vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone; (11) olefins such as ethylene, propylene, isobutylene, butadiene, and isoprene;

(12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc., (13) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) ) Acrylamide, N- (p-
Aminosulfonylphenyl) acrylamide, N- [1
Acrylamides such as-(3-aminosulfonyl) naphthyl] acrylamide, N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1-
(3-aminosulfonyl) naphthyl] methacrylamides such as methacrylamide and N- (2-aminosulfonylethyl) methacrylamide, and o-aminosulfonylphenyl acrylate, m-aminosulfonylphenyl acrylate, and p-aminosulfonylphenyl acrylate , Unsaturated sulfonamides such as acrylates such as 1- (3-aminosulfonylphenylnaphthyl) acrylate, o-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, 1- (3 Unsaturated sulfonamides such as methacrylates such as -aminosulfonylphenylnaphthyl) methacrylate;

Further, a monomer copolymerizable with the above monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers may be modified with, for example, glycidyl acrylate, glycidyl methacrylate, or the like, but is not limited thereto. The copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the copolymer preferably has an acid value of 0.
-10 meq / g, more preferably 0.2-5.0 meq / g. The preferred molecular weight of the copolymer is 10,000 to 100,000. If necessary, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, and an epoxy resin may be added to the copolymer. Such alkali-soluble polymer compounds can be used alone or in combination of two or more, and are used in an amount of 80% by weight or less of the photosensitive layer.

Further, as described in US Pat. No. 4,123,279, phenol having a C3-8 alkyl group as a substituent such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin and formaldehyde are used. It is preferable to use a condensate together to improve the oil sensitivity of the image. In the photosensitive composition of the present invention, it is preferable to add a cyclic acid anhydride, a phenol, or an organic acid in order to increase the sensitivity.

US Pat. No. 4,115,1 discloses cyclic acid anhydrides.
No. 28, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-
Endoxy-Δ ⁴ -tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone,
4 ', 4 "-trihydroxy-triphenylmethane,
4,4 ', 3 ", 4" -tetrahydroxy-3,5
3 ', 5'-tetramethyltriphenylmethane and the like.

Further, as the organic acids, JP-A-60-8
No. 8942, JP-A-2-96755 and the like, there are sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphoric esters and carboxylic acids, and specifically, p-toluene sulfone acid,
Dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,
4-dimethoxybenzoic acid, phthalic acid, terephthalic acid,
Examples thereof include 1,4-cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, and ascorbic acid. The proportion of the above-mentioned cyclic acid anhydrides, phenols or organic acids in the photosensitive layer is 0.05 to 1%.
It is preferably 5% by weight, more preferably 0.1 to 5% by weight. The photosensitive layer in the present invention is provided with a method described in Japanese Patent Application Laid-Open No. Sho 62-251740 and Japanese Patent Application No. 2-251780 in order to broaden the stability of processing under development conditions (so-called development latitude).
Non-ionic surfactants described in JP-A-188-188, JP-A-59-121044, Japanese Patent Application No. 2-1.
Amphoteric surfactants such as those described in 15992 can be added.

Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, monoglyceride stearate, polyoxyethylene sorbitan monooleate, and polyoxyethylene nonyl phenyl ether. . Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and alkylimidazoline type (for example, trade name Levon 15, Sanyo Chemical Co., Ltd.)
Manufactured).

The proportion of the nonionic surfactant or amphoteric surfactant in the photosensitive layer is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight. A printing-out agent for obtaining a visible image immediately after exposure or a dye or pigment as an image coloring agent can be added to the photosensitive layer in the invention. Representative examples of the printing-out agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, o-naphthoquinonediazide-4 described in JP-A-50-36209 and JP-A-53-8128 is disclosed.
A combination of a sulfonic acid halide and a salt-forming organic dye, and JP-A-53-36223 and JP-A-54-74728.
No. 60-3626, No. 61-143748, No. 61-151644 and No. 63-58440 in combination with trihalomethyl compounds and salt-forming organic dyes. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear print-out images.

As the colorant for the image, other dyes can be used in addition to the above-mentioned salt-forming organic dye. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS,
Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) and the like. Further, Japanese Patent Application Laid-Open No.
The dyes described in JP 93247 A are particularly preferred. The photosensitive layer according to the invention is formed by dissolving the above components in a solvent that dissolves the above components and coating the solution on an aluminum plate as a support. The solvent used here is described in
Organic solvents as described in JP-A-251739 may be used alone or as a mixture. For example, the solvent used for forming the back coat layer can be used as the solvent. The photosensitive composition for forming the photosensitive layer of the present invention is dissolved and dispersed at a solid content of 2 to 50% by weight, and is coated and dried on a support.

The amount of the photosensitive layer to be coated on the support varies depending on the application, but is generally 0.1% by weight after drying.
3 to 4.0 g / m ² is preferred. As the amount of coating decreases, the amount of exposure for obtaining an image may be small, but the film strength is reduced. As the coating amount increases, the exposure amount is required but the photosensitive film becomes strong. For example, when used as a lithographic printing plate, a printing plate having a high printable number (high printing durability) can be obtained. In the photosensitive layer of the present invention, a surfactant for improving the coated surface quality, for example, JP-A-62-170
A fluorine-based surfactant as described in JP-A-950 can be added. A preferable addition amount is 0.001 to 1.0% by weight of the photosensitive layer, and more preferably 0.000 to 1.0% by weight.
5 to 0.5% by weight.

[0058]

[Negative photosensitive layer] As the negative photosensitive composition, those having a photocurable photosensitive composition comprising a photosensitive diazo compound, a photopolymerizable photosensitive composition, a photocrosslinkable photosensitive composition and the like can be used. Among these, the photocurable photosensitive composition comprising a photosensitive diazo compound will be described in detail with reference to examples. As such a photosensitive diazo compound, an aromatic diazonium salt and a reactive carbonyl group-containing organic condensing agent,
Particularly, a diazo resin obtained by condensing an aldehyde such as formaldehyde or acetaldehyde or an acetal in an acidic medium is preferably used. The most typical one is p
There are condensates of diazophenylamine and formaldehyde. The synthesis of these diazo resins is described, for example, in U.S. Pat.Nos. 2,679,498, 3,050,502, and 3,311,6.
No. 05 and 3,277,074.

Further, as the photosensitive diazo compound, a co-condensed diazo compound of an aromatic diazonium salt and a substituted aromatic compound containing no diazonium group described in JP-B-49-48,001 is preferably used. A co-condensed diazo compound with an aromatic compound substituted with an alkali-soluble group such as a carboxyl group or a hydroxyl group is preferred. Furthermore, Japanese Patent Application Nos. 1-130,493 and 2-321,82.
Photosensitive diazo compounds obtained by condensing an aromatic diazonium salt with a reactive carbonyl compound having an alkali-soluble group described in JP-A Nos. 3 and 2-299,551 are also preferably used. As a counter anion of these diazonium salts, there are diazo resins using mineral acids such as hydrochloric acid, hydrobromic acid, sulfuric acid and phosphoric acid or inorganic anions such as double salts with zinc chloride, but are substantially water-insoluble and organic. Solvent-soluble diazo resins are particularly preferred. Such preferred diazo resins are described in detail in JP-B-47-1167 and U.S. Pat. No. 3,300,309.

Further, JP-A-54-98613 and JP-A-56-98613 describe the same.
A diazo resin having a counter anion of a halogenated Lewis acid such as tetrafluoroboric acid and hexafluorophosphoric acid and a perhalic acid such as perchloric acid and periodic acid as described in JP-A-121031 is preferably used. Can be JP-A-58-209733 and JP-A-62-17573.
No. 1, 63-262643, diazo resins having a long chain alkyl group-containing sulfonic acid as a counter anion are also preferably used. The photosensitive diazo compound accounts for 5 to 50% by weight, preferably 8 to 20% by weight in the photosensitive layer.
In the range of

The photosensitive diazo compound used in the present invention is preferably used in combination with a lipophilic polymer compound soluble or swellable in alkaline water as a binder. Such a lipophilic polymer compound may be the same as (1) used in the positive photosensitive composition described above.
(1) having a monomer represented by (13) as its constituent unit
Copolymers having a molecular weight of 10,000 to 200,000 can be mentioned, and polymer compounds obtained by copolymerizing the following monomers (14) and (15) as constituent units can also be used. (14) maleimide, N-acryloylacrylamide, N-acetylacrylamide, N-propionylacrylamide, N- (p-chlorobenzoyl) acrylamide, N-acetylacrylamide, N-acryloylmethacrylamide, N-acetylmethacrylamide,
Unsaturated imides such as N-propionyl methacrylamide, N- (p-chlorobenzoyl) methacrylamide,
(15) N- [2- (acryloyloxy) -ethyl]
Unsaturated monomers having a crosslinkable group in the side chain such as -2,3-dimethylmaleimide, N- [2- (methacryloyloxy) -ethyl] -2,3-dimethylmaleimide and vinyl cinnamate;

Further, a monomer copolymerizable with the above monomer may be copolymerized. In addition, a copolymer obtained by copolymerization of the above-mentioned monomers may be modified with, for example, glycidyl acrylate, glycidyl methacrylate, or the like, but is not limited thereto. The copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the copolymer preferably has an acid value of 0.
-10 meq / g, more preferably 0.2-5.0 meq / g. The preferred molecular weight of the copolymer is 10,000 to 100,000. Further, a polyvinyl butyral resin, a polyurethane resin, a polyamide resin, or an epoxy resin may be added to the copolymer as needed. Novolak-type resins, phenol-modified xylene resins, polyhydroxystyrenes, polyhalogenated hydroxystyrenes, and alkali-soluble resins containing phenolic hydroxyl groups as disclosed in JP-A-51-34711 may also be used. it can.

Such alkali-soluble polymer compounds can be used alone or in combination of two or more.
It is usually contained in the photosensitive layer in the range of 40 to 95% by weight. In the photosensitive composition of the present invention, a sensitizing agent (for example, Japanese Patent Application Laid-Open No.
No. 27, a half-esterified product of a styrene-maleic anhydride copolymer with an alcohol, a novolak resin, a 50% fatty acid ester of p-hydroxystyrene, etc.). Further, a plasticizer may be added to the photosensitive composition in order to impart flexibility and abrasion resistance of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate,
Examples include tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers and polymers of acrylic acid or methacrylic acid, and tricresyl phosphate is particularly preferred.

In the photosensitive composition of the present invention, for example, phosphoric acid, phosphorous acid, citric acid, oxalic acid, dipicolinic acid, benzene sulfonic acid, naphthalene sulfonic acid, sulfo Salicylic acid, 4-
Methoxy-2-hydroxybenzophenone-5-sulfonic acid, tartaric acid and the like may be added. In the photosensitive composition of the present invention, a printing-out agent for obtaining a visible image immediately after exposure, or a dye such as a dye or a pigment as an image coloring agent can be added.

As such dyes, those which change color by reacting with free radicals or acids are preferably used. For example, Victoria Pure Blue BOH (Hodogaya Chemical), Oil Yellow # 101, Oil Yellow # 1
03, Oil Pink # 312, Oil Red, Oil Green BG, Oil Blue BOS, Oil Blue # 60
3. Oil black BY, oil black BS, oil black T-505 (or more, Orient Chemical Co., Ltd.)
), Patent pure blue (manufactured by Sumitomo Sangoku Chemical), crystal violet (CI42555), methyl violet (CI42535), ethyl violet, rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI5201)
5) triphenylmethane series represented by brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4-p-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide,
Examples of diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes changing from colored to colorless or different colored tones.

On the other hand, examples of the color changing agent that changes from colorless to colored include leuco dyes and, for example, triphenylamine,
Diphenylamine, o-chloroaniline, 1,2,3-
Triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p,
p ', p "-tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p', p" -triamino-o-methyltriphenylmethane, p, p'-bis -Dimethylaminodiphenyl-4-anilinonaphthylmethane, p, p ', p "
Primary or secondary arylamine dyes represented by -triaminotriphenylmethane. Particularly preferred are triphenylmethane-based and diphenylmethane-based dyes, more preferred are triphenylmethane-based dyes, and particularly Victoria Pure Blue BOH. The dye is usually contained in the photosensitive layer in an amount of about 0.5 to 10% by weight, more preferably about 1 to 5% by weight.

In the photosensitive layer according to the invention, cyclic acid anhydrides, phenols, organic acids or higher alcohols can be added to enhance the developability. The photosensitive composition of the present invention is dissolved in a solvent that dissolves the above-mentioned components, and applied on an aluminum plate as a support. As the solvent used here, an organic solvent described in JP-A-62-251739 may be used alone or as a mixture. For example, the solvent used when forming the back coat layer can be used. The photosensitive composition used in the present invention is dissolved and dispersed at a solid content of 2 to 50% by weight, and is coated and dried on a support. The amount of the photosensitive layer applied on the support varies depending on the application, but is generally from 0.3 to 4.0 g / m2 in terms of the weight after drying.
² is preferred. As the amount of coating decreases, the amount of exposure for obtaining an image may be small, but the film strength is reduced. As the coating amount increases, the exposure amount is required but the photosensitive film becomes strong. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained. In the photosensitive composition of the present invention, a surfactant for improving the coated surface quality can be added as in the case of the positive photosensitive composition described above. In producing the photosensitive printing plate of the present invention, either the back coat layer on the back surface or the photosensitive layer on the front surface may be coated on the support first, or both may be coated simultaneously.

[0068]

[Matte layer] A mat layer is provided on the surface of the photosensitive layer provided as described above in order to reduce the time required for evacuation during contact exposure using a vacuum printing frame and to prevent printing blur. Is also good. As a method of forming such a mat layer,
Specifically, JP-A-50-125805, JP-B-57
No. 6,658, and No. 61-28986.
No. 62337, a method of thermally fusing a solid powder, and the like.

[0069]

[Development processing] The PS plate thus obtained is passed through a transparent original image using a carbon arc lamp, mercury lamp, metal halide lamp,
After being exposed by an actinic ray using a xenon lamp, a tungsten lamp or the like as a light source, it is developed. Conventionally known aqueous alkali solutions can be used as the developer and replenisher for the PS plate. For example, sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, potassium And inorganic alkali agents such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium.
Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolan, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine and pyridine are also used.

These alkaline agents may be used alone or in combination of two or more. Among these alkali agents, a silicate aqueous solution such as sodium silicate or potassium silicate is particularly preferable as a developer for a positive PS plate. The reason is that the ratio of silicon oxide SiO ₂ which is a component of silicate to alkali metal oxide M ₂ O (generally [SiO ₂ ] / [M
_This is because the developability can be adjusted by the molar ratio (2O]). However, since the aqueous solution of the alkali metal silicate is strongly basic having a pH of 12 or more, it has a disadvantage of dissolving the aluminum support. Because of this problem, it has not been possible to reduce [SiO ₂ ] / [M ₂ O] or increase the concentration of the aqueous solution in the past. Aluminum can be prevented from being eluted into the developer. Therefore, the composition of the aqueous alkali silicate solution can be freely selected according to the developing system to be employed.

Further, using an automatic developing machine, the conventional PS
When developing a plate, by adding an aqueous solution (replenisher) having a higher alkali strength than the developer to the developer, a large amount of PS can be obtained without replacing the developer in the development tank for a long time.
It is known that plates can be processed continuously. This replenishment system is also preferably applied in the present invention. In the present invention, [SiO ₂ ] / [M ₂
O] and the concentration are not restricted, so that a replenisher having a high activity can be obtained, which has a great effect on reducing the replenishment amount and the waste liquid. The developer and replenisher used for the development of the positive and negative PS plates of the present invention may contain, if necessary, for the purpose of accelerating or suppressing the developing property, dispersing developing scum, and increasing the ink affinity of the printing plate image area. Various surfactants and organic solvents can be added. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, and glycerin fatty acid partial esters. , Sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester , Polyoxyethylenated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, and trialkylamine oxides;

Fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts,
Dialkyl sulfosuccinates, linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl- N-oleyltaurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, Fatty acid monoglyceride sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, polyoxyethylene styryl phenyl ether sulfate salts, Alkyl phosphate phosphate salts, polyoxyethylene alkyl ether phosphate salts, polyoxyethylene alkyl phenyl ether phosphate salts, partially saponified styrene / maleic anhydride copolymers, partial olefin / maleic anhydride copolymers Anionic surfactants such as saponified products and naphthalene sulfonate formalin condensates,

Cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylenepolyamine derivatives;
Examples include amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the surfactants mentioned above, the term "polyoxyethylene" can be read as a polyoxyalkylene such as polyoxymethylene, polyoxypropylene, or polyoxybutylene, and these surfactants are also included. Further preferred surfactants are fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Examples of such a fluorine-based surfactant include an anionic type such as a perfluoroalkyl carboxylate, a perfluoroalkyl sulfonate and a perfluoroalkyl phosphate, an amphoteric type such as a perfluoroalkyl betaine, and a perfluoroalkyltrimethylammonium salt. Cationic and perfluoroalkylamine oxides, perfluoroalkylethylene oxide adducts, oligomers containing perfluoroalkyl groups and hydrophilic groups, oligomers containing perfluoroalkyl groups and lipophilic groups, perfluoroalkyl groups, hydrophilic groups and lipophilic Non-ionic types such as group-containing oligomers, urethanes containing perfluoroalkyl groups and lipophilic groups are included.

The surfactants described above can be used alone or in combination of two or more.
It is added in the range of 0.01 to 10% by weight, more preferably 0.01 to 5% by weight. Suitable organic solvents are those having a solubility in water of about 10% by weight or less, preferably 5% by weight or less. For example, 1
-Phenylethanol, 2-phenylethanol, 3-
Phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1-butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl Alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol or 4-methylcyclohexanol, N-phenylethanolamine or N-phenyldiethanolamine can be exemplified. The content of the organic solvent is 0.1 to 5% by weight based on the total weight of the developer. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because when the amount of the surfactant is small and the amount of the organic solvent is large, the organic solvent is not completely dissolved, and therefore, it is impossible to expect good developing property.

A reducing agent can be further added to the developer and replenisher used for developing the PS plate of the present invention. This is to prevent stains on the printing plate, and is particularly effective when developing a negative PS plate containing a photosensitive diazonium salt compound. Preferred organic reducing agents include phenolic compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin, and 2-methylresorcin; and amine compounds such as phenylenediamine and phenylhydrazine. Further preferred inorganic reducing agents include sodium, potassium and ammonium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, bisulfite, diphosphite, thiosulfate and dithionite. Salts and the like can be mentioned. Among these reducing agents, sulfites are particularly excellent in the effect of preventing fouling. These reducing agents are preferably added to the developing solution at the time of use at a concentration of 0.0.
It is contained in the range of 5 to 5% by weight.

An organic carboxylic acid can be further added to the developer and the replenisher. Preferred organic carboxylic acids are aliphatic and aromatic carboxylic acids having 6 to 20 carbon atoms. Specific examples of the aliphatic carboxylic acid include caproic acid, enantiic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. . Further, unsaturated fatty acids having a double bond in the carbon chain or branched fatty acids may be used. The aromatic carboxylic acid is a compound in which a carboxyl group is substituted on a benzene ring, a naphthalene ring, an anthracene ring, or the like. Specifically, o-chlorobenzoic acid, p-chlorobenzoic acid, o-
Hydroxybenzoic acid, p-hydroxybenzoic 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-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid , 1-naphthoic acid, 2-naphthoic acid and the like, and hydroxynaphthoic acid is particularly effective.

The above aliphatic and aromatic carboxylic acids are preferably used as a sodium salt, a potassium salt or an ammonium salt in order to increase the water solubility. The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited, but is not limited to 0.1.
If it is lower than 1% by weight, the effect is not sufficient, and 10% by weight
With the above, not only the effect cannot be further improved but also dissolution may be hindered when another additive is used in combination. Therefore, the preferable addition amount is 0.1 to 1 with respect to the developing solution at the time of use.
0% by weight, more preferably 0.5 to 4% by weight. If necessary, the developer and the replenisher may further contain a conventionally known compound such as an antifoaming agent, a water softener, or an organic boron compound described in Japanese Patent Publication No. 1-57895.

Examples of water softeners include polyphosphoric acid and its sodium, potassium and ammonium salts,
Aminopolycarboxylic acids such as ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid and 1,3-diamino-2-propanoltetraacetic acid; Their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetraminehexa (methylenephosphonic acid), hydroxyethylethylenediaminetri (methylene Phosphonic acid) and 1-hydroxyethane-1,1-
Examples include diphosphonic acids and their sodium, potassium and ammonium salts.

The optimum value of such a water softener varies depending on its chelating power, the hardness of the hard water used and the amount of the hard water. 0.01 to 5% by weight, more preferably 0.01 to 0.01% by weight.
It is in the range of 5% by weight. If the added amount is less than this range, the intended purpose is not sufficiently achieved, and if the added amount is larger than this range, an adverse effect on an image portion such as color omission appears. The remaining component of the developer and replenisher is water, but may optionally contain various additives known in the art. It is advantageous from the viewpoint of transportation that the developing solution and the replenishing solution are concentrated solutions in which the content of water is smaller than that at the time of use, and are diluted with water at the time of use. The degree of concentration in this case is suitably such that each component does not cause separation or precipitation.

The PS plate thus developed is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and starch derivatives. These treatments can be used in various combinations for the post-treatment of the PS plate of the present invention. In recent years, in the plate making / printing industry, automatic developing machines for PS plates have been widely used in order to rationalize and standardize plate making operations. This automatic developing machine generally comprises a developing section and a post-processing section, and comprises a device for transporting a PS plate, each processing solution tank and a spray device, and pumps the exposed PS plate horizontally while pumping it. Each developing solution is sprayed from a spray nozzle to perform a developing process. Recently, a method has been known in which a PS plate is immersed and transported in a processing liquid tank filled with a processing liquid by a guide roll in the liquid or the like. In such an automatic processing, the processing can be performed while replenishing each processing liquid with a replenisher according to the processing amount, the operating time, and the like. Further, a so-called disposable processing method in which processing is performed with a substantially unused processing liquid can also be applied. The lithographic printing plate obtained by such a process is set on an offset printing machine and used for printing a large number of sheets.

[0082]

The present invention will be described in more detail with reference to the following examples.

Example 1 0.01% copper and 0.09% titanium were added to 99.5% aluminum.
JISA1 containing 3%, iron 0.3% and silicon 0.1%
Rolling a 0.24 mm thick roll of 050 aluminum
The surface was grained using a 20% by weight aqueous suspension of mesh pumicestone (manufactured by Kyoritsu Ceramics) and a rotating nylon brush (6-10 nylon), and then thoroughly washed with water. This was immersed in a 10% by weight aqueous sodium hydroxide solution (containing 5% by weight of aluminum), etched so that the amount of aluminum dissolved was 5 g / m ² , and washed with running water. Further, the mixture was neutralized with 20% by weight of nitric acid and washed with water. Next, in a 1% by weight nitric acid aqueous solution (containing 0.5% of aluminum), a square wave alternating waveform voltage (current ratio r = 0.90, voltage of 10.5 volts at the anode and 9.3 volts at the cathode) was used. Kosho 58-
The electrolytic surface roughening treatment was carried out at an anode charge of 160 coulomb / dm ² using the current waveform described in Examples of No. 5796). After washing with water, it was immersed in a 10% by weight aqueous solution of sodium hydroxide at 40 ° C. to dissolve 1 g of aluminum.
After etching so as to obtain m ² , the substrate was washed with water. Then 5
It was immersed in a 30% by weight aqueous sulfuric acid solution at 5 ° C. for 2 minutes, desmutted, and then washed with water.

Next, in a 30% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) at 50 ° C., a current density of 15 A / dm
^Using a DC current of ^2, the amount of oxide film was 2.5 g / surface.
m ^2, electrolysis time 80 seconds so that the back surface 0.2 g / m ^2, was subjected to anodic oxidation film formation processing. Further, washing and drying were performed. Sampling was performed from any 10 places on the aluminum support obtained as described above, and each physical property value was measured. A sample was formed on the back surface of the anodic oxide film by a platinum-palladium vapor deposition method, and the sample was observed by an ultra-high resolution scanning electron microscope. The pore density was 1.03 to 1.50 × 10 ¹¹ / cm ² (average 1.3 × 10
¹¹ / cm ² ), and the pore diameter was 55 to 70 ° (average 62 °). Center line average roughness is 0.56 μm on average (Ra display)
The average reflection density measured with a Macbeth RD920 reflection densitometer was 0.28. A polyurethane resin (trade name: Estan # 571) is provided on the back surface of the obtained aluminum support.
5, Monsanto Co.) A backcoat solution prepared by dissolving 0.2 parts by weight in 16 parts by weight of ethylene glycol monomethyl ether and 24 parts by weight of methyl ethyl ketone was applied and dried to a dry weight of 0.2 g / m ^2. did. An undercoat solution having the following composition was applied to the surface of the aluminum support thus obtained, and dried at 80 ° C. for 30 seconds. The undercoat layer after drying was 30 mg / m ² .

<Undercoat liquid>-0.1 g of aminoethylphosphonic acid-0.15 g of phenylphosphonic acid-0.1 g of β-alanine-40 g of methanol-60 g of pure water Apply the following photosensitive solution on top
After drying at 00 ° C. for 1 minute, a positive photosensitive lithographic printing plate was obtained. The coating amount after drying was 1.7 g / m ² .

<Photosensitive solution> Esterified product of pyrogallol-acetone resin and 0.43 g of 1,2-diazona phtoquinone-5-sulfonyl chloride (described in Example 1 of US Pat. No. 3,635,709) Cresol formaldehyde novolak resin 1.1 g (meta to para ratio: 6: 4, average molecular weight 1100, containing unreacted cresol 0.5%) m-cresol formaldehyde resin 0.3 g (weight average molecular weight) 1700, number average molecular weight 600, containing 1% of unreacted cresol) N- (p-aminosulfonylphenyl) acryl 0.2 g amide / n-butyl acrylate / diethylene glycol monomethyl ether methacrylate (40:40:20) Copolymer of

• pn-octylphenol formaldehyde resin 0.02 g • naphthoquinonediazide-1,2-diazide-4-0.01 g sulfonic acid chloride • benzoic acid 0.02 g • tetrahydrophthalic anhydride 0.05 g 4- (p-N, N-di (ethoxycarbonyl) amid 0.02 g nophenyl) -2,6-bis (trichloromethyl) -s-triazine 4- (p-N- (p-hydroxybenzoyl) Ami 0.02 g nophenyl) -2,6-bis (trichloromethyl) -s-triazine 2-trichloromethyl-5- (4-hydroxysty 0.01 g glyl) -1,3,4-oxadiazole・ Dye in which the counter ion of Victoria Pure BOH is converted to 1-naphtha 0.01 g of lensulfonic acid ・ The counter ion of ethyl violet is 6-hydroxy 0.1 g 1 g naphthalenesulfonic acid dyes Megafac was acid F-177 (Dainippon Ink & Chemicals 0.06 g (Ltd.), fluorine-based surfactant) Methyl ethyl ketone 15 g · 1-Methoxy-2-propanol 10 g

On the photosensitive layer coated in this way, based on the method described in Example 1 of JP-B-61-28986, (methyl methacrylate / ethyl acrylate / sodium acrylate = 68/20/12) The matte layer was formed by electrostatic spraying of the aqueous copolymer solution.
Many photosensitive lithographic printing plates (PS plates) thus obtained were prepared. The PS plate obtained in this way is 100
It was cut into 3 mm x 800 mm and 30 sheets were prepared. The 30 sheets were stacked, and one piece of cardboard having a thickness of about 0.5 mm was placed on each of the upper and lower sides and taped at the four corners, and then packaged with aluminum kraft paper. This was further packaged in a cardboard case and taped, and then a truck transport test was performed in the following manner. That is, the above case was loaded on a large truck (10-ton vehicle) normally used for transporting PS plates in Japan, and the trucks were kept engaged in PS transport services for two months. The traveling distance of the truck during this period was approximately 9,000 km (almost 2/1 on expressways / general roads). Then, the above case was lowered from the truck and unpacked, and the presence or absence of abrasion on the PS plate was determined one by one. Separately, the obtained photosensitive lithographic printing plate 1,500 sheets placed an iron wear plate up and down in real Sho 62-6035 Patent Publication No. 3, pp such manner of FIG. 1, the bolt at a pressure of 300 kg / cm ² 5 months from May to October in a warehouse without air conditioning in a closed mass transport mode
After standing for months, the bolts were removed and the adhesion between the PS plates was examined. The results are shown in Table 1 below.

A large number of PS plates obtained as described above were prepared, and these were passed through a manuscript film from a distance of 1 m.
Exposure was performed for 60 seconds using a kw metal halide lamp. Next, a developer DP-4 manufactured by Fuji Photo Film Co., Ltd.
(1: 8), Rinse solution FR-3 (1: 7), Fuji Photo Film Co., Ltd. automatic developing machine Stavlon 900D
Processed through. Here, the developer DP-4 (1: 8)
Was measured by a commercially available pH meter and found to be 13.1. In the automatic developing machine, the PS plate is DP-4.
The time of immersion in (1: 8) was 12 seconds. By the above development, any of the samples can be developed well,
The back coat layer does not peel off from the back,
The back coat layer did not peel off during subsequent handling or printing. The results obtained are shown in Table 1 below. Also, no insoluble matter was generated in the developer.

Example 2 An aluminum support treated in the same manner as in Example 1 until desmutting with sulfuric acid and washing with water was placed in a 30% by weight aqueous sulfuric acid solution (containing 0.9% by weight of aluminum) at 60 ° C. with a current density of 10 A. / Dm ² DC current, oxide film amount on the surface
2.7 g / m ^2, was subjected to anodic oxidation film formation treatment such that the back surface 0.24 g / m ^2. The electrolysis time at this time is 130
Seconds. Further, washing and drying were performed. Next, when the respective physical property values were measured in the same manner as in Example 1, the pore density of the back anodic oxide film was 1.03 to 1.50 × 10 ¹¹ / cm ²
(Average 1.30 × 10 ¹¹ / cm ² ), pore size 55-70
Å (average 60 °). The center line average roughness of the surface was 0.56 μm on average, and the reflection density was 0.29 on average.

On the back surface of the obtained aluminum support, a back coat solution obtained by dissolving 0.3 part by weight of a phenoxy resin (trade name: Fenote YP-50, manufactured by Toto Kasei) in 40 parts by weight of ethylene glycol monomethyl ether was dried. The coating was dried at a concentration of 0.2 g / m ² . An undercoat layer, a photosensitive layer, and a mat layer were formed on the surface of the aluminum support thus obtained in the same manner as in Example 1.
A PS plate was formed. This PS plate was subjected to a truck transport test and an adhesion test in a mass packaging form in the same manner as in Example 1. Further, in the same manner as in Example 1, it was examined whether or not the back coat layer was peeled during development and subsequent handling. The results obtained are shown in Table 1 below.

Example 3 Anodization was carried out at a current density of 18 A / d in a 20% by weight aqueous sulfuric acid solution (containing 0.8% of aluminum) at 45 ° C.
m ² , the amount of oxide film on the front surface was 2.9 g / m ² , the amount of oxide film on the back surface was 0.27 g / m ² , and the electrolysis time was 90 seconds. Processing was performed. Next, when the respective physical properties were measured in the same manner as in Example 1, the pore density of the anodic oxide film on the back surface was 0.65 to 0.6.
95 × 10 ¹¹ pieces / cm ² (average 0.80 × 10 ¹¹ pieces / cm ² )
And the pore diameter is 55-69Å (average 62Å),
The center line average roughness of the surface was 0.56 μm, and the reflection density was 0.32 on average. A back coat solution in which 0.3 parts by weight of a polyvinyl butyral resin (trade name: Denka butyral 3000-K: manufactured by Denki Kagaku Kogyo KK) was dissolved in 40 parts by weight of ethylene glycol monomethyl ether on the back surface of the obtained aluminum support. Is 0.2 g / dry weight
m ^2, and dried in the same manner as in Example 1.
An S plate was prepared and various characteristics were examined. The results are shown in Table 1 below.

COMPARATIVE EXAMPLE 1 An aluminum support treated in the same manner as in Example 1 until desmutting and washing was carried out at 45 ° C. in a 7% by weight aqueous sulfuric acid solution (containing 0.4% by weight of aluminum) at a current density of 25 A /
Using a direct current of dm ^2, an anodic oxide film forming treatment was performed for 50 seconds, and the physical properties of the film were examined. Oxide film of the support surface at 2.4 g / m ^2, was 0.22 g / m ² on the back surface. Next, the physical property value of the film on the back surface measured by the same method as in Example 1 was as follows: the pore density was 4.5 × 10 ^{10 to} 6.0 × 10
^The number was ¹⁰ / cm ² (average 5.3 × 10 ¹⁰ / cm ² ), and the pore diameter was 40 to 50 ° (average 45 °). An undercoat layer, a photosensitive layer, and a mat layer were formed on this support in the same manner as in Example 1 to prepare a PS plate, and the performance of the PS plate was evaluated. The results are shown in Table 1 below.

COMPARATIVE EXAMPLE 2 An aluminum support treated to desmut and water washing in the same manner as in Example 1 was placed in a 15% by weight aqueous sulfuric acid solution (containing 0.5% by weight of aluminum) at 20 ° C. and a current density of 30 A /
using a direct current of dm ^2, subjected to 35 seconds oxide film formation process, were examined physical properties of the film, the amount of oxide film, the surface at 1.7 g / m ^2, be 0.16 g / m ² on the back surface The pore density is 4.5-5.9 × 10 ¹⁰ / cm ² (average 5.2 × 10 ¹⁰ / cm ² ), and the pore diameter is 54-65 ° (average 60 °).
Met. An undercoat layer, a photosensitive layer, and a mat layer were formed on this support in the same manner as in Example 2 to prepare a PS plate, and the performance of the PS plate was evaluated. The results are shown in Table 1 below.

COMPARATIVE EXAMPLE 3 In the same manner as in Example 1, a desmutted and washed aluminum support was placed in a 7% by weight aqueous sulfuric acid solution (containing 0.4% by weight of aluminum) at 20.degree.
/ By 45 seconds anodized dm ^2, as the anodized film weight, surface ^{1.8g / m 2, 0.17g / m} 2 on the back surface
An oxide film was formed. The resulting film has a pore density of 4.5.
~ 6.0 × 10 ¹⁰ pieces / cm ² (average 5.3 × 10 ¹⁰ pieces / cm ² )
And the pore diameter was 40 to 50 ° (mean 45 °). This aluminum support was treated in the same manner as in Example 3 to prepare a PS plate. The results of performance evaluation of this PS plate are shown in Table 1 below. Comparative Example 4 A PS plate was prepared and the performance of the PS plate was evaluated in the same manner as in Example 1 except that the backcoat liquid was not applied. The results are shown in Table 1 below.

[0096]

Table 1 Table 1 Example 1 Example 2 Example 3 Aluminum Pore Average Density × 10 ¹¹ 1.35 1.30 0.80 (Pieces / cm ² ) Oxide Film Average Pore Diameter (62) 62 60 62 Amount of Oxide Film ( g / m ² ) 0.22 0.24 0.27 Back coat layer Polyurethane phenoki Polyvinyl butane resin Resin Resin Chiral resin ──────────────────────────────擦 Abrasion during transportation A A C Performance evaluation Large-scale packaging adhesive A A B Peeling of film layer during development A A C Peeling of film layer during handling A A B Insoluble matter in developer None None None ── ─────────────────────────────────Table 1 (continued) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Aluminum average pore density × 10 ¹¹ 0.53 0.52 0.53 1.35 (pcs / cm ² ) Oxide film on back side of support Average pore diameter (ポ) 45 60 45 62 Amount of oxide film (g / m ² ) 0.22 0.18 0.18 0.22 Backcoat layer Polyurethane phenoki Polyvinyl butyl None Tanresin Resin Resin Chiral resin ───────────────────────────────輸送 Transport abrasion D DD A Performance evaluation Large-scale packaging adhesive C C CA Peeling of film layer during development D D DA Peeling of film layer during handling BBCA Insolubles in developer-- Yes Yes 性能 Performance evaluation: A: Not at all B: Almost No (approximately 1 in 500) C: Occurs occasionally (approximately 2 in 100) D: Occurs frequently (5 or more in 100) As can be seen from Table 1, the anodic oxide film of the present invention By providing a back coat layer on the back side of the support through the intermediary, it suppresses the scratches due to vibration during transportation In addition, adhesion in a mass packaging form and accompanying peeling of the film were also suppressed.
Further, there was no problem in development. That is, even if a large number of sheets are transported and stored without interleaf paper, the photosensitive layer is not scratched and the plates do not adhere to each other. Further, since the back coat layer provided on the back surface of the aluminum support has good adhesiveness to the aluminum support, it does not peel off during handling such as packaging and transportation, development processing, and printing. Further, no insoluble matter was generated during the development.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41N 3/03 B41N 1/14

Claims (2)

(57) [Claims] 1. A photosensitive lithographic printing plate wherein a photosensitive layer is provided on the surface of an aluminum support and a back coat layer is provided on the back of the support, wherein the aluminum support has a pore average density of 7. 0 × 10 ¹⁰ 〜1.0 × 10 ¹² /
A photosensitive lithographic printing plate characterized in that an anodic oxide film having a pore size of 50 to 300 ° in cm ² is provided in an amount of 0.2 to 2.0 g / m ² . 2. The pore average density is 1.0 × 10 ^{11 to} 1.0.
The photosensitive lithographic printing plate according to claim 1, wherein the density is × 10 ¹² / cm ² .