JPH03213863A - Development processing method for original plate for waterless planographic printing plate - Google Patents

Abstract

PURPOSE:To prevent the flawing of a silicone rubber layer and to improve image quality and halftone reproducibility by processing the above original plate with a processing liquid essentially consisting of water having <9 pH, then processing the plate with an alkaline processing liquid having >=9 pH. CONSTITUTION:The original plate for a waterless planographic printing plate successively having a photosetting photosensitive layer and the silicone rubber layer on a base is processed with the processing liquid essentially consisting of the water having <9 pH at the time of subjecting the above-mentioned original plate to development processing. Namely, two kinds of the processing liquid (1st development processing liquid) essentially consisting of the water having <9 pH and the alkaline processing liquid (2nd development processing liquid) having >=9 pH are used as the developing soln. The flawing of the silicone rubber layer is prevented in this way and the excellent image quality and halftone reproducibility are obtd. In addition, the safety and environment preserving property are improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for developing a waterless lithographic printing plate precursor, and more specifically, it prevents scratches on the silicone rubber layer and improves image quality and mesh. The present invention relates to a method for developing a waterless lithographic printing plate precursor that has excellent point image reproducibility, good safety and environmental protection, and improved ink receptivity.

[Background of the Invention] Various types of waterless lithographic printing plate precursors have been known, including those having a structure in which a photosensitive layer and an ink repellent layer are sequentially coated on a support.

This waterless lithographic printing plate precursor is imagewise exposed and then developed, and the developer used for this is conventionally known to use a hydrocarbon-based organic solvent such as Isopar H or toluene. However, as a developing treatment method for the waterless lithographic printing plate precursor, for example, Japanese Patent Publication No. 56-30856
The publication discloses that a printing original plate having a photopolymerizable adhesive layer and a silicone rubber layer sequentially provided thereon is exposed to light in an image pattern, and then developed using a developer such as a paraffinic hydrocarbon-based developer capable of swelling the silicone rubber. After removing the silicone rubber layer in the unexposed areas, the photopolymerizable adhesive layer remaining in the unexposed areas is removed using a water-based treatment solution to prevent paper powder from adhering to the non-image areas. It is described that a lithographic printing plate with good reproducibility can be obtained without damaging the surface.

However, since this development method uses organic solvents such as paraffin hydrocarbons, the silicone rubber layer in non-image areas is partially swollen and removed.
It is difficult to completely prevent the silicone rubber layer in the non-image areas from being scratched, and this can be said to be a serious problem.

On the other hand, Japanese Patent Publication No. 63-33140 discloses a method that prevents scratches on the silicone rubber layer and improves reproducibility. After exposing to light in the shape, part or all of the photosensitive layer in the image area is eluted using a processing liquid such as water or alcohol that can dissolve part or all of the photosensitive layer in the image area,
A technique has been disclosed in which the silicone rubber layer in the image area is removed by rubbing the printing plate in the presence of water or a solvent containing water as a main component, which does not have the effect of swelling the silicone rubber layer.

However, in this method, part or all of the photosensitive layer dissolves, and the interfacial adhesive force with the silicone rubber layer in the image area decreases, resulting in a floating state.

This silicone rubber layer is strongly adhered near the edges of the image area, so it is necessary to rub it strongly to remove the silicone rubber layer in this area, which easily scratches the silicone rubber layer in the non-image area. There is a problem.

Therefore, as a result of various studies on the above-mentioned problems, the present inventors have developed a method for developing a waterless lithographic printing plate precursor having a photocurable photosensitive layer, in which the silicone rubber layer is first removed, and then the photosensitive layer is removed. The above-mentioned problems can be solved by removing the above, and the present invention has been accomplished based on this point.

[Object of the Invention] Therefore, the object of the present invention is to prevent the silicone rubber layer from being scratched, to provide excellent image quality and halftone image reproducibility, and to provide good safety and environmental protection, as well as to provide a method for ink deposition. An object of the present invention is to provide a method for developing a waterless lithographic printing plate precursor with improved properties.

[Structure of the Invention] The object of the present invention is to provide: l) A method for developing a waterless lithographic printing plate precursor having a photocurable photosensitive layer and a silicone rubber layer sequentially on a support, in which water with a pH of less than 9 is the main component. and 2) a photocurable photosensitive layer according to item 1. Each of these was achieved by a method for developing a waterless lithographic printing plate precursor, which is characterized in that it contains a diazonium compound.

The present invention will be specifically explained below.

The developing solution used in the developing method for the waterless lithographic printing plate precursor of the present invention is a processing solution containing water as a main component with a pH of less than 9 (hereinafter referred to as the first development processing solution) and an alkaline processing solution with a pH of 9 or more. 2f with & (hereinafter referred to as the second developing solution)
! Similar types are used.

The development processing method for a waterless lithographic printing plate precursor of the present invention is that the exposed plate material is treated with a processing solution whose main component is water with a pH of less than p) 19, and then treated with an alkaline processing solution with a pH of 9 or more. It is in.

First, the first developing solution is used to remove the silicone rubber layer in the non-image area of the printing plate, and water is essentially used as the developing solution.

The first developing solution contains 0 surfactant (the surfactant used in the second developing solution described below can be used as this surfactant) as another component if necessary.
．． The organic solvent may be added in an amount of 0.01% to 10% by weight, and the organic solvent may be added within a range that does not dissolve the silicone rubber layer or the photosensitive layer. Additionally, dyes may be added to identify the image on the plate.

The second developing solution is used to remove the photosensitive layer and improve ink adhesion, preferably contains potassium silicate, and is preferably adjusted to p) 111 to 14. Further, an anionic or nonionic surfactant can be added, and further an organic carboxylic acid and/or its salt or sulfite can be added.

As anionic surfactants, higher alcohols (Ca
-C22) Sulfuric ester salts [e.g., sodium salt of lauryl alcohol sulfate, sodium salt of cetyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, "T-Ball B-81J
(trade name, manufactured by Shell Chemical Co., Ltd.), sodium chloride alkyl sulfate, aliphatic alcohol phosphate ester salts (e.g., sodium salt of cetyl alcohol phosphate, etc.), alkylaryl sulfonates (e.g., dodecylbenzenesulfone) sodium salts of isopropylnaphthalenesulfonic acid, sodium salts of sinapthalenedisulfonic acid, sodium salts of metanitrobenzenesulfonic acid, etc.), sulfonates of alkylamides, sulfonates of dibasic fatty acid esters (e.g. acid dioctyl ester,
sodium sulfosuccinate dihexyl ester, etc.). Among these, sulfonate salts are particularly preferably used.

The content of the anionic surfactant is 1% to 30% by weight, preferably 3% to 30% by weight, based on the entire liquid.
It is 15% by weight.

Furthermore, various types of nonionic surfactants can be used.

That is, nonionic surfactants can be broadly classified into polyethylene glycol type and polyhydric alcohol type, and either of these can be used in the present invention, but polyethylene glycol type is most effective. This is a nonionic surfactant.

Among them, ethylene oxide group (-CH2CH20-
)3 or more, and) ILB value (HLB value is Hyd
rophile Lipophile Ba1ance
A nonionic surfactant having 5 or more (more preferably 8 to 20) surfactants is more preferable.

Furthermore, among nonionic surfactants, those having both an ethylene oxy group and a propylene oxide group are particularly preferable, and among these, those having an ILB value of 8 or more are more preferable.

Preferred examples of the nonionic surfactant used in the present invention include compounds represented by the following general formulas [I] to -numerical formulas [■].

Formula [1 R-0-(CH2C)+20) n)l-Formula [2] General formula [3 L R-0-(CH2CH2)m-'(CH2CH2O)
nH-Formula [4 formulas [5] General formula [6] HO(C2H40)a-(C3H60)b-(C2H4
0) cH - Formula [7] Formula [8] ) 10 - (CH2C820) nH - Formula [1] to - Formula [8], R represents a hydrogen atom or a monovalent organic group. The organic group includes, for example, a linear or branched alkyl group which may have a substituent having 1 to 30 carbon atoms (for example, an aryl group such as a phenyl group), and an alkylcarbonyl group in which the alkyl moiety is the above-mentioned alkyl group. and a phenyl group which may have a substituent (eg, a hydroxyl group, an alkyl group as described above, etc.).

a, b, c, m, n, x and y each represent an integer of 1 to 4 degrees.

Next, specific examples of the nonionic surfactant used in the present invention will be shown.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene behenyl ether , polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene stearylamine, polyoxyethylene oleylamine, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abyssalin Ethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene glycer monostearate,
Polyoxyethylene propylene glycol monostearate, oxyethylene oxypropylene block polymer, disdecinated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polyoxybrobylene adduct, glycerol monostearate, sorbitan mono The weight average molecular weight of the nonionic surfactant used in the present invention, such as laurate and polyoxyethylene sorbitan monolaurate, is preferably in the range of 300 to 10,000, particularly preferably in the range of 500 to 5,000.

One nonionic surfactant may be contained alone, or two or more types may be used in combination.

Organic carboxylic acid and/or added to the developer according to the present invention
Or as a salt thereof, preferably an aliphatic carboxylic acid having 6 to 20 carbon atoms and an aromatic carboxylic acid.

Specific examples of aliphatic carboxylic acids having 6 to 20 carbon atoms include caproic acid, enantylic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mystylic acid, palmitic acid, stearic acid, etc. Preferred are alkanoic acids having 8 to 12 carbon atoms. Further, fatty acids having a double bond in the carbon chain or those with branched carbon chains may be used.

The above aliphatic carboxylic acids are preferably used as sodium or potassium salts or ammonium salts in order to improve water solubility.

Aromatic carbonic acids include a benzene ring, naphthalene ring, anthracene ring, etc. with an alkoxyl group W t! Specific compounds include benzoic acid, 0-chlorobenzoic acid, po-roti-P, folic acid, 0-hydroxybenzoic acid, p-hydroxybenzoic acid, and 0-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, among others, aromatic carboxylic acids are particularly effective. The above aromatic carboxylic acid is preferably used as a sodium or potassium salt or an ammonium salt in order to improve water solubility.

The amount of organic carboxylic acid added to the developer of the present invention is preferably in the range of 0.1% to 10% by weight, more preferably in the range of 0.5% to 4% by weight.

As the sulfite used in the present invention, sodium sulfite, potassium sulfite, lithium sulfite ammonium sulfite, etc. are useful.

The following additives can be further added to the developer used in the present invention. For example, JP-A-58-751
Neutral salts such as NaCR%KCI and KBr described in JP-A-52, EDTA%N as described in JP-A-58-190952
Chelating agents such as TA, [Co (N)13) al Cl1-COC4 described in JP-A-59-121336;
complexes such as '2.6H20, anionic or amphoteric surfactants such as sodium alkylnaphthalene sulfonate described in JP-A-50-51324, N-tetradecyl N, and N-dihydroxyethyl betaine, U.S. Patent No. 4,374,
Nonionic surfactants such as tetramethyldecynediol described in No. 920, cationic polymers such as quaternary compounds of methyl chloride of p-dimethylaminomethyl polystyrene described in JP-A-55-95946;
Ampholytic polymer electrolyte such as a copolymer of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, JP-A-57-1
Reducing inorganic salts such as sodium sulfite described in Japanese Patent Publication No. 92952, inorganic lithium compounds such as lithium chloride described in JP-A No. 58-59444, organic lithium compounds such as lithium benzoate described in Japanese Patent Publication No. 50-34442,
Organometallic surfactants containing silicon, titanium, etc. described in JP-A-59-75255, organoboron compounds described in JP-A-59-84241, European Patent No. 1010
Examples include additives such as quaternary ammonium salts such as tetraalkylammonium oxides described in Specification No. 10.

For the photosensitive layer suitable for the developer of the present invention, a diazo compound, a photopolymerizable compound, a photocrosslinkable compound, etc. are used. Preferably, diazo compounds are used.

Examples of photosensitive substances used in the photosensitive layer of the present invention include:
First, the photosensitive layer used in the present invention includes various diazo resins, but preferably a diazo resin represented by a condensate of p-diazodiphenylamine and formaldehyde, which is water-insoluble and organic solvent. Soluble, preferably Japanese Patent Publication No. 47-1167 and No. 57-4
Those that are water-insoluble and soluble in ordinary organic solvents, such as those described in Japanese Patent No. 3890, are used. Particularly preferred is a diazo resin represented by the following general formula [11].

General Formula [I] [In the formula, RI R2 and R3 represent a hydrogen atom, an alkyl group, or an alkoxy group, and R4 represents a hydrogen atom, an alkyl group, or a phenyl group.

X represents PF6 or BF4, and Y represents -NH--S- or -0-. ] Examples of the diazo monomer in the diazo resin used in the present invention include 4-diazo-diphenylamine, l
-Diazo-4-N,N-dimethylaminobenzene, 1-
Diazo-4-N, N-diethylaminobenzene, l-diazo-4-N-ethyl-N-hydroxyethyl-minobenzene, l-diazo-4-N-methyl-N-hydroxyethylaminobenzene, 1-diazo-2 , 5-jethoxy-4-benzoylaminobenzene, l-diazo-4-
N-benzylaminobenzene, l-diazo-4-N,N
-dimethylaminobenzene, 1-diazo-4-morpholinobenzene, 1-diazo-2,5-dimethoxy-4-p
-Tolylmercaptobenzene, 1-diazo-2-ditoxy-4-N,N-dimethylaminobenzene, p-diazodimethylaniline, l-diazo-2,5-dibutoxy-4-morpholinobenzene, l-diazo -2,5-jethoxy-4-morpholinobenzene, 1-diazo-2,5
-dimethoxy-4-morpholinobenzene, 1-diazo-
2,5-jethoxy-4-p-tolylmercaptobenzene, l-diazo-4-N-ethyl-N-hydroxyethylaminobenzene, 1-diazo-3-ethoxy-4-N
-Methyl-N-benzylaminobenzene, 1-diazo-
3-chloro-4-N,N-diethylaminobenzene, l
-Diazo-3-methyl-4-pyrrolidinobenzene, 1-
Diazo-2-chloro-4-N,N-dimethylamino-5
-methoxybenzene, l-diazo-3-methoxy-4-
Examples include pyrrolidinobenzene, 3-methoxy-4-diazodiphenylamine, 3-ethoxy-4-diazodiphenylamine, 3(n-propoxy)-4-diazodiphenylamine, and 3-(isopropoxy)-4-diazodiphenylamine.

Examples of the aldehyde used as a condensing agent with the diazo monomer include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and benzaldehyde.

Furthermore, water-soluble diaso resins can be obtained by using chloride ions, tetrachlorozinc acid, etc. as anions, and boron tetrafluoride, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 4,4° -biphenyldisulfonic acid, 2,5-dimethylbenzenesulfonic acid,
By using 2-nitrobenzenesulfonic acid, 2-methoxy-4-hydroxybenzoyl-hensensulfonic acid, etc., it is possible to obtain a diazo resin soluble in organic solvents. Particularly preferably, a diazo resin made of hexafluorophosphoric acid is used.

The diazo resin is preferably used in combination with a film-forming resin, particularly a polymer compound having a hydroxyl group. Particularly preferably, the polymer compound is a copolymer of 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate having an aliphatic hydroxyl group in its side chain, and other copolymerizable mercury. Can be mentioned.

In addition to these, polyvinyl butyral resins, polyurethane resins, polyamide resins, epoxy resins, novolak resins, natural resins, etc. may be added as necessary.

In addition, various polymer compounds can be used as the binder used in combination with the diazonium salt, but preferably,
Monomers having an aromatic hydroxyl group such as those described in Japanese Patent No. 4-98613, such as N-(4-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, m-, or copolymers of p-hydroxystyrene, o-, m-, or p-hydroxyphenyl methacrylate, etc., with other monomers, such as those described in U.S. Pat. No. 4,123,276. Examples include polymers containing ethyl acrylate units or hydroxyethyl methacrylate units as main repeating units.

In addition to these polymers, natural resins such as polyvinyl butyral resin, polyurethane resin, polyamide resin, epoxy resin, novolac resin, shellac, rosin, polyvinyl alcohol, U.S. Patent No. 3.751,
257, linear polyurethane resins as described in U.S. Pat. No. 3,660,097, phthalated polyvinyl alcohol resins, epoxy resins condensed from bisphenol A and epichlorohydrin, acetic acid. Contains celluloses such as cellulose and cellulose acetate phthalate.

Examples of the alkali-soluble resin include novolac resin, vinyl polymer having a phenolic hydroxyl group, and JP-A-55-5
Examples include condensation resins of polyhydric phenols and aldehydes or ketones described in Japanese Patent No. 7841. Examples of the novolac resin include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-57841, and JP-A-55-127553. Examples include copolycondensation resins of p-substituted phenol and phenol or cresol and formaldehyde as described in .

The diazo resin used in the present invention is used in a mixture with a binder resin, and when this binder resin is taken as 100, the diazo resin may range from 30 to 200 (weight ratio), preferably from 50 to 150, and more preferably from 50 to 150. is 70-1
The range is 20.

Other dyes, pigments such as pigments, fat-sensitizing agents, plasticizers, surfactants, etc. can be added to these photosensitive compositions. The amount of these additives added is 0.1% to 20% by weight, preferably 0.1% to 20% by weight in the solid content of the photosensitive layer.
It is used in a range of 5% to 10% by weight.

-CH-CH as a photosensitive group in the main chain or side chain of the polymer.
Also included are those whose main component is a photosensitive polymer such as -C--containing polyesters, polyamides, and polycarbonates. For example, JP-A-55-404
15, photosensitive polyesters obtained by condensation of phenylene diethyl acrylate with hydrogenated bisphenol A and triethylene glycol, as described in U.S. Pat. No. 2,956,878. Examples include photosensitive polyesters derived from (2-probeliden)malonic acid compounds C such as cinnamylidenemalonic acid and difunctional glycols.

Furthermore, a photopolymerizable composition comprising an addition polymerizable unsaturated compound may also be mentioned.

Examples of unsaturated alcohols include alcohols (for example, ethanol, propatool, hexanol, octatool, cyclohexanol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylolpropane,
acrylic or methacrylic acid esters of pentaerythritol, etc.), amines (e.g. methylamine, ethylamine, butylamine, benzylamine, ethylenediamine, diethylenetriamine, hexamethylenediamine, xylylenediamine, dimethylamine, diethylamine, ethanolamine, jetanolamine) , aniline, etc.) and glycidyl acrylate or glycidyl methacrylate.

Carboxylic acids (e.g. acetic acid, propionic acid, benzoic acid,
acrylic acid, methacrylic acid, succinic acid, maleic acid, phthalic acid, tartaric acid, citric acid, etc.) and glycidyl acrylate or glycidyl methacrylate.

Amide derivatives (eg, acrylamide, methacrylamide, N-methylolacrylamide, methylenebisacrylamide, etc.), reaction products of epoxy compounds and acrylic acid or methacrylic acid, etc. can be used.

As the photopolymerization initiator, the following can be used.

Benzoin derivatives such as hengein methyl ether, benzoin isopropyl ether, α, α-dimethoxy α-phenylacetophenone, benzophenone, 2.4-
Benzophenone conductors such as dichlorobenzophenone, methyl 0-benzoylbenzoate, 4,4°-bis(dimethylamino)benzophenone, 4,4-bis(diethylamino)benzophenone, 2-chlorothioxanthone, 2
- Thioxanthone derivatives such as isopropylthioxanthone, anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone, acridone derivatives such as N-methylacridone and N-butylacridone, α, α
- Jetoxyacetophenone, benzyl, fluorocarbon, xanthone, uranyl compound, halogen compound, etc.

A binder is also preferably added to the photopolymerizable composition. As a binder, one used in combination with a diazo resin is used, and more preferably a photocrosslinkable copolymer having an ethylenically unsaturated bond in the side chain described in Japanese Patent Publication No. 49-17874 is used. be done.

In addition to the above, the photosensitive layer contains a dye for making the image visible after exposure or development, such as Victoria Pure Blue B.
Photosensitive diazo as a substance that generates acid upon exposure (photoacid generator), such as triphenylmethane-based and diphenylmethane-based dyes such as OH (manufactured by Hodogaya Chemical Co., Ltd.) and Oil Blue '603 (manufactured by Orient Chemical Industry Co., Ltd.). compounds, 0-naphthoquinonediazide compounds, aromatic compounds having a triheromethyl group, such as oxadiazole compounds having a triheromethyl group or S- having a triheromethyl group.
Triazine compounds, etc. (specifically, JP-A-62-1121
(see Publication No. 62).

In addition, the photosensitive layer contains alkyl ethers (e.g., ethyl cellulose, methyl cellulose, etc.), fluorine-based surfactants, nonionic surfactants (e.g., Pluronic L64 (manufactured by Asahi Denka), etc.) to improve coating properties. It may contain a plasticizer (for example, polyethylene glycol, tricresyl phosphate, acrylic acid or methacrylic acid polymer, etc.) and a stabilizer (for example, phosphoric acid, etc.) for imparting flexibility to the membrane.

The silicone rubber used in the present invention is a linear organic polymer having a repeating unit represented by the following general formula [I] and having a molecular weight of several thousand to hundreds of thousands and a hydroxyl group in the main chain or at the end of the main chain. Those containing siloxane as a main component are preferred.

General formula [I] +5i-0+? l Here, n is an integer of 2 or more, R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxyl group, a vinyl group, an aryl group, a silanol group (OH group), and R
It is preferable that 60% or more of the methyl groups are methyl groups. The silanol group (O)I group) may be located either in the main chain or at the end of the main chain, and is preferably located at the end.

The silane coupling agent (or silicone crosslinking agent) used in the present invention is R4,5tX4-n (wherein n is an integer of 1 to 3, and R is alkyl, aryl, alkenyl, or a combination thereof. It represents a monovalent group, and these groups may have a functional group such as )\rokene, amine, hydroxy, alkoxy, aryloxy, thiol, etc.

2 X is 10H, -0R2, -0Ac, -o-N-c,
Represents a substituent such as -CN, -Br, -■3, etc. Here, R2 and R3 represent the same thing as R above, and R2 and R3 may be the same or different. Moreover, AC represents an acetyl group. ) is a silane compound represented by

That is, the silicone rubber useful in the present invention is obtained by a condensation reaction between such a silicone base polymer and a silicone crosslinking agent such as those listed above.

Specific examples of the silane coupling agent used in the present invention include HN[(CH2)3si(OMe)3]2% vinyltriethoxysilane, CF(CH2)3si(OMe)
e) 3, CH35l (DAC) 3, R5(C)1
2) :+Si(OMe)s, vinyl tris(methyl ethyl ketoxime) silane, and the like.

The silicone rubber described above is also available as a commercial product, such as YE-3085 manufactured by Toshiba Silicone Co., Ltd. Other useful silicone rubbers can be produced by reacting the above-mentioned base polymer with a silicone oil having repeating units represented by the following general formula [II], or by reacting a silicone oil in which about 3% of R is a vinyl group. It can also be obtained by addition reaction of silicone with a base polymer or reaction of the silicone oils with each other.

Rl ((wherein, R has the same meaning as R, which is a substituent of the polymer represented by general formula [1], ■ is an integer of 2 or more, and n is an integer of 0 or 1 or more) such In order to obtain silicone rubber by crosslinking reaction, the crosslinking reaction is carried out using a catalyst.This catalyst includes tin, zinc, cobalt, lead,
Organic carboxylates of metals such as calcium, manganese, etc.
For example, dibutyltin laurate, tin(II) octoate, cobalt naphthenate, or chloroauric acid may be used.

Additionally, fillers can be mixed in to improve the strength of the silicone rubber and to obtain a silicone rubber that can withstand the frictional forces generated during printing operations. Silicone rubber mixed with filler in advance is commercially available as silicone rubber stock or silicone rubber dispersion, and when it is preferable to obtain a silicone rubber film by coating as in the present invention, RTV
Alternatively, dispersion of LTV silicone rubber is preferably used. An example of this is )--L/
Silinia -:/manufactured by syl off 23.5RX-
There are silicone rubber dispersions for paper coating such as 257 and 5H237.

In the present invention, it is preferable to use condensation and crosslinking type silicone rubber.

The silicone rubber layer preferably contains a silane coupling agent having an amino group in order to further improve adhesiveness.

Examples of preferable silane coupling agents include the following.

(a) H2NCH2CH2NH(CH2) 3si
(OCH3) 5(b) H2NCE2CH2NH(C
H2) sS t (OCH3) 2 (CH3) (c
) )12N ((,f!2) 351 (OEt)
3. The silicone rubber layer used in the present invention may further contain a small amount of photosensitizer.

The silicone rubber layer used in the present invention is prepared by dissolving silicone rubber in a suitable solvent, applying it onto the photosensitive layer, and drying it.

The support of the present invention is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as metal plates such as aluminum, zinc, copper, and steel, and metal plates such as chromium, zinc, Examples include metal plates plated or vapor-deposited with copper, nickel, aluminum, iron, etc., paper, plastic films, glass plates, resin-coated paper, paper covered with metal foil such as aluminum, and the like.

Among these, aluminum plates are preferred.

The treatment for the support itself to improve the adhesion is not particularly limited, and includes various surface roughening treatments.

The support may have a primer layer, and the primer layer may include, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate. Examples include polyvinyl acetate copolymers, vinyl acetate copolymers, phenoxy resins, polyurethane resins, polycarbonate resins, polyacrylonitrile butadiene, and polyvinyl acetate. It is possible to add to these primer layers a compound that generates an acid upon exposure to light and a dye that changes color or fades when exposed to acid.

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

The thickness of each layer constituting the plate material of the present invention is as follows. That is, the support has a thickness of 50 to 400 μm, preferably 100 μm.
~300 Alm, photosensitive layer 0.05~10 μm,
Preferably 05-5μm, silicone rubber layer 0.1-5μm
It is 10 μm, preferably 0.5 to 2 μm.

In the present invention, a protective layer may be provided on the upper surface of the silicone rubber layer, if necessary.

The following margins [Examples] The present invention will be described below with reference to Examples, but the present invention is not limited to these.

Example 1 [Manufacture of aluminum plate a] An aluminum plate with a thickness of 0.2 mm was immersed in a 3% aqueous sodium hydroxide solution to degrease it, washed with water, and then diluted with 1% hydrochloric acid concentration.
In an aqueous solution with a boric acid concentration of 1%, electrolytic etching was performed at a temperature of 25°C for 5 minutes at a rate of 3A/dm2, and after washing with water, etching was performed in an aqueous solution of 40% sulfuric acid at a temperature of 1.5°C at a temperature of 30°C.
Anodize for 2 minutes at A/dm2, wash with water,
% sodium metasilicate aqueous solution at a temperature of 85°C for 37 seconds, and further immersed in water (pH 8.5) at a temperature of 90°C for 25 seconds, washed with water, and dried to obtain an aluminum plate a.

Next, a brimer composition shown below was applied, dried at 85°C for 3 minutes, and heated to 100°C using a 3KW ultra-high pressure mercury lamp.
0 IDJ Full-surface exposure of 7 cm2 was performed. 10 more
It was dried at 0° C. for 4 minutes to form a primer layer with a thickness of 0.8 μm.

[Primer layer composition] (1) Diazo resin - 18 parts (2) Copolymer resin 192 with a molar ratio of 2-hydroxyethyl methacrylate and methyl methacrylate of 34/66
Part (3) Methyl cellosolve 900 parts Apply photosensitive composition 1 having the following composition on the above-mentioned brimer layer,
It was dried at 100° C. for 2 minutes to form a photosensitive layer with a thickness of 0.5 μm.

[Photosensitive composition (1) Diazo resin - 140 parts (2) 2-hydroxyethyl methacrylate, N-(4
-Hydroxyphenyl) methacrylamide and acrylic acid in a molar ratio of 50747/3.
50 parts (3) Victoria Pure Blue BOH (dye manufactured by Hodogaya Chemical Co., Ltd.) 1 part (4) Methyl cellosolve 900 parts Synthesis of Diazo Resin-1 Diazo Resin-1 was synthesized as follows.

14.5 g (50 mmol) of p-diazodiphenylamine sulfate was dissolved in 409 g of concentrated sulfuric acid under water cooling. To this reaction solution, 1.35 (45 mmol) of paraformaldehyde was slowly added so that the reaction temperature did not exceed 10°C.

This reaction mixture was added dropwise to 500 ml of ethanol under water cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 100 ml of pure water, and 6.8
A cold concentrated aqueous solution of 1 g of zinc chloride was added. After filtering the resulting precipitate, it was washed with ethanol, and then washed with 150
Dissolved in ml pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The formed precipitate is collected by filtration, washed with water, and dried to form a diazo resin.
I got 1.

Next, the following silicone rubber composition was coated on the above photosensitive layer so that the dry weight was 2.0 g and 7 m2.
It was dried at ℃ for 10 minutes to obtain a lithographic printing plate material that did not require dampening water.

[Silicone rubber layer composition] Dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight 52,000) 100 parts triacetoxymethylsilane 10 parts dibutyltin laurate 0.8 parts Isopar G (manufactured by Esso Chemical) 900 parts of the above plate material After a positive film was vacuum-adhered to the top surface, exposure was performed using a metal halide lamp as a light source.

Next, development was performed using the processing apparatus shown in FIG. The diameter of the brushes of brush roll 1, 2, and 3 are all 100 mm.
, and the brush bristles are 0.15 mm and 0.1 thick, respectively.
5mm%0.08mm, and the length was 20mm. In addition, nylon 6.10 was used for the brush bristles. The rotational speed of the brush roll 1.2 is 120 m at the peripheral speed of the outer diameter.
The rotation speed of the brush roll 3 was adjusted to 20 m/min.

Water was used as the processing liquid in the first developing section, and a 6-fold dilution of Konica PS plate developer 5DR-1 with water was used as the processing liquid in the second developing section.

The temperature of each treatment solution was controlled at 30°C. 1st
The processing time in the developing section was 100 seconds, and the processing time in the second developing section was 25 seconds.

In the printed plate after the treatment, the silicone rubber layer and photosensitive layer in the image area were removed, and the halftone dots were well reproduced in the range of 2% to 99%.

Comparative Example 1 Processing was carried out in the same manner as in Example 1, except that the processing liquid in the first developing section was replaced with the following developer.

[Developer] (pHlo, a) Hensyl alcohol 8 parts by weight Perex NBL (manufactured by Kao Corporation, anionic surfactant) 10 parts by weight Soda carbonate (Na2CO3) 2 parts by weight Water
80 parts by weight As a result, the halftone dot reproducibility ranged from 3% to 96%, and the reproducibility in shadow areas was particularly poor.

There were some streak-like scratches on the silicone rubber layer, which appeared to be caused by brushing.

Example 2 Except for using 25 parts of diazo resin-1 in the photosensitive composition,
A printing plate material exactly the same as in Example 1 was produced, and the same exposure treatment as in Example 1 was performed.

The reproduction range of halftone dots was well reproduced from 2% to 98%. No damage to the silicone rubber layer was observed.

Comparative Example 2 Except for using 25 parts of diazo resin-1 in the photosensitive composition,
A printing plate material exactly the same as in Example 1 was produced, and the same exposure treatment as in Example 1 was performed.

Processing was carried out in the same manner as in Example 1, except that the processing solution in the first developing section was replaced with the developer of Comparative Example 1.

As a result, the halftone dot reproducibility was 3% to 94%. There were some streak-like scratches on the silicone rubber layer, which appeared to be caused by brushing.

Example 3 A printing plate material was prepared in exactly the same manner as in Example 1, except that 100 parts of diazo resin-1 was used in the photosensitive composition, and the same exposure treatment as in Example 1 was carried out.

The reproduction range of halftone dots was well reproduced from 3% to 99%. No damage to the silicone rubber layer was observed.

Comparative Example 3 A printing plate material was prepared in exactly the same manner as in Example 1, except that 100 parts of diazo resin-1 was used in the photosensitive composition, and the same exposure treatment as in Example 1 was performed.

Processing was carried out in the same manner as in Example 1, except that the processing solution in the first developing section was replaced with the developer of Comparative Example 1.

As a result, the halftone dot reproduction range was 5% to 96%. There were some streak-like scratches on the silicone rubber layer, which appeared to be caused by brushing.

[Effects of the Invention] The present invention prevents damage to the silicone rubber layer and improves image quality by treating the silicone rubber layer with a treatment liquid whose main component is water with a pl (less than 9) and then with an alkaline treatment liquid with a pH of 9 or more. It has excellent halftone image reproducibility and is safe and environmentally friendly.

Furthermore, the ink receptivity is improved. Furthermore, the above effects are more pronounced when the photocurable photosensitive layer contains a diazonium compound.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a developing machine having a first developing section (A) and a second developing section (B) used in the present invention. 1.2.3...Brush 4.5.6.7...Roller 8.9...Developer tank 10...Pump 11.12.13.14...Shower 15.16.17...Guide plate

Claims (1)

[Scope of Claims] 1) A method for developing a waterless lithographic printing plate precursor having a photocurable photosensitive layer and a silicone rubber layer sequentially on a support, in which treatment is performed with a processing liquid containing water as a main component and having a pH of less than 9. 1. A method for developing a waterless lithographic printing plate precursor, which comprises processing with an alkaline processing solution having a pH of 9 or higher. 2) A method for developing a waterless lithographic printing plate precursor, wherein the photocurable photosensitive layer according to claim 1 contains a diazonium compound.