Developer for dry ps plates

Claim 2

A developer for developing a dry presensitized plate for use in making lithographic printing plates requiring no dampening water during printing, comprising a substrate provided thereon with, in order, a primer layer, a light-sensitive layer and a silicone rubber layer; the developer comprising: (i) at least one organic solvent capable of dissolving or swelling unexposed portions of the light-sensitive layer and whose solubility in water at ordinary temperature is not more than 20% by weight; (ii) at least one basic compound; (iii) at least one surfactant; and (iv) water.

Claim 3

A developer of claim 1 wherein the organic solvent is at least one member selected from the group consisting of diisobutyl ketone, acetophenone, isophorone, diethyl succinate, methyl benzoate, diethyl oxalate, dimethyl phthalate, isobutyl acetate, benzyl benzoate, ethylene glycol monophenyl ether, ethylene glycol dibutyl ether, ethylene glycol benzyl ether, diethylene glycol di-n-butyl ether, ethylene glycol diacetate, n-amyl alcohol and benzyl alcohol.

Claim 4

A developer of claim 2 wherein the organic solvent is at least one member selected from the group consisting of diethyl succinate, dimethyl phthalate, benzyl benzoate, ethylene glycol monophenyl ether, diethylene glycol di-n-butyl ether, ethylene glycol diacetate and benzyl alcohol.

Claim 5

A developer of claim 1 wherein the amount of the organic solvent ranges from 1 to 30% by weight on the basis of the total weight of the developer.

Claim 6

A developer of claim 4 wherein the amount of the organic solvent ranges from 2 to 20% by weight on the basis of the total weight of the developer.

Claim 7

A develper of claim 1 wherein the basic compound is at least one member selected from the group consisting of ammonia, methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, propylamine, butylamine, amylamine, dipropylamine, dibutylamine, diamylamine, tripropylamine, tributylamine, methyldiethylamine, ethylenediamine, trimethylenediamine, tetramethylenediamine, polyethyleneimine, benzylamine, N,N-dimethylbenzylamine, N,N-­diethylbenzylamine, N,N-dipropylbenzylamine, o-, m- or p-methoxy- or methyl-benzylamine, N,N-di(methoxybenzyl)amine, β -phenylethylamine, ε , δ -phenylamylamine, γ -phenylpropylamine, cyclohexylamine, aniline, monomethylaniline, dimethylaniline, toluidine, benzidine, α - or β-­naphthylamine, o-, m- or p-phenylenediamine, pyrrolidine, piperidine, piperazine, morpholine, urotropin, diazabicycloundecane, pyrrole, pyridine, quinoline, hydrazine, phenylhydrazine, N,N′-­diphenylhydrazine, hydroxylamine, semicarbazide, tetraalkyl ammonium hydroxide, aminobenzoic acid, formamide, acetamide, N,N-­dimethylformamide, N,N-dimethylacetamide, acetoanilide, monoethanolamine, triethanolamine, 2-(2-aminoethyl)-ethanol, 2-amino-­2-methyl-1,3-propanediol, 2-amino-1,3-propanediol, 2-amino-2-­hydroxymethyl-1,3-propanediol; salts of octanoic acid with monoethanolamine or diethanolamine, sodium methylate, sodium ethylate, sodium propylate, potassium methylate, potassium ethylate, potassium propylate, lithium methylate, lithium ethylate; amide, ethylamide and dipropylamide of sodium, potassium and lithium; sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, calcium carbonate, barium carbonate, sodium bicarbonate, potassium bicarbonate, sodium phosphate, potassium phosphate, sodium silicate, potassium silicate and sodium metasilicate.

Claim 8

A developer of claim 1 wherein the basic compound is added to the developer in an amount required for adjusting pH of the developer to 8.5 to 11.5.

Claim 9

A developer of claim 7 wherein the basic compound is added to the developer in an amount required for adjusting pH of the developer to 9 to 10.5.

Claim 10

A developer of claim 1 wherein the surfactant is selected from anionic and non-ionic surfactants.

Claim 11

A developer of claim 9 wherein the surfactant is at least one member selected from the group consisting of alkylnaphthalene sulfonate salts, alkyl diphenyl ether sulfonate salts, linear alkylbenzene sulfonate salts, polyoxyethylene alkylphenyl ether sulfate ester salts, polyoxyethylene alkylphenyl ethers and polyoxyethylene-polyoxypropylene block copolymers.

Claim 12

A developer of claim 1 wherein the amount of the surfactant ranges from 0.01 to 30% by weight on the basis of the total weight of the developer.

Claim 13

A developer of claim 11 wherein the amount of the surfactant ranges from 0.1 to 20% by weight on the basis of the total weight of the developer.

Claim 14

A developer of claim 1 wherein the amount of the organic solvent ranges from 2 to 20% by weight on the basis of the total weight of the developer; the basic compound is added to the developer in an amount required for adjusting pH of the developer to 9 to 10.5; and the amount of the surfactant ranges from 0.1 to 20% by weight on the basis of the total weight of the developer.

Claim 15

A developer of claim 1 wherein it further comprises at least one dye to stain image areas simultaneously with the development.

Claim 16

A developer of claim 1 wherein the light-sensitive layer of the dry presensitized plate comprises i) 1.0 to 99.9 parts by weight of monomers which have a boiling point of not less than 100° C, which are non-volatile at room temperature and which have at least one photopolymerizable ethylenically unsaturated double bond; ii) 0.1 to 20.0 parts by weight of a photopolymerization initiator; optionally iii) 0.01 to 1.0 parts by weight of a heat polymerization inhibitor; and optionally iv) 0.01 to 95.0 parts by weight of polymers or inorganic powder.

Claim 17

A developer of claim 1 wherein the light-sensitive layer of the dry presensitized plate comprises a) copolymers which are soluble in water or get swallen with water at ordinary temperature and whose copolymerization components are at least a monomer represented by the following general formula (I): CH₂=CR-CO-Z-C(R₄)(R₅)-C(R₃)=C(R₂)(R₁)      (I) (wherein R represents a hydrogen arom or a methyl group; R₁ to R₅ each represents a hydrogen or halogen atom, or a carboxyl, sulfo, nitro, cyano, amido, amino, alkyl, aryl, alkoxy, aryloxy, alkylamino, arylamino, alkylsulfonyl or arylsulfonyl group; Z represents an oxygen or sulfur atom or a group -NH- or -NR′- (wherein R′ is an alkyl group)) and an ethylenically unsaturated monomer having hydrophilic group(s); b) a monomer or an oligomer having at least one photopolymerizable ethylenically unsaturated double bond; and c) a photopolymerization initiator.

Claim 18

A developer of claim 1 wherein the silicone rubber layer of the dry presensitized plate mainly comprises linear organic polysiloxane having the following repeating units and a molecular weight ranging from several thousands to several tens of thousands: wherein R is an alkyl group having 1 to 10 carbon atoms, provided that not less than 60% of R is methyl group.

Claim 19

A developer of claim 1 wherein the primer layer of the dry presensitized plate is a layer of hardened gelatin, epoxy resin or polyurethane resin.

Claim 20

A developer of claim 1 wherein the substrate of the dry presensitized plate is an aluminum plate or a composite sheet composed of a polyethylene terephthalate film bonded to an aluminum plate.

Claim 21

A developer of claim 1 wherein the presensitized plate has a plastic protective layer.