Abstract A novel photopolymerizable resin composition consists of (1) 1.26 to 3.78 parts by weight of a monoester of a polyhydric aliphatic alcohol with acrylic or methacrylic acid, (2) as a polymeric binder, an aqueous solution of one part by weight of a partially hydrolyzed polyvinyl acetate having a hydrolysis degree of 95 to 60 mol percent and an average polymerization degree of 300 to 2,000 or one part by weight of a methyl cellulose of an average polymerization degree of 160 having a hydroxylpropoxyl substituent and (3) as a photopolymerization initiator, 1 to 5 percent by weight, based on the total weight of the resin components of the above (1) and (2) constituents, of at least one uranyl salt and 0.0072 to 0.72 percent by weight, on the same basis, of azobisisobutyronitrile. A presensitized plate prepared by coating a metal plate with said photopolymerizable resin composition in a thickness of an order of microns is water washable and can be used to form a relief image. Further, a sheet of said photopolymerizable resin composition having a thickness of 0.1 to 3 mm. is directly used in printing and is water washable when it is exposed to actinic light in contact with a screen negative.
A photopolymerizable resin composition containing further as the (1) constituent of claim 1, 1-10 percent by weight, based on the weight of the above-stated acrylate or methacrylate, of a monofunctional acid amide derivative of acrylic or methacrylic acid.
Claim 2
Dependent Claim
30 words
A water-developable presensitized plate consisting essentially of a metal plate having coated thereon a film of an order of microns of the photopolymerizable resin composition as claimed in claim 1.
Claim 3
Dependent Claim
27 words
A material for a printing plate consisting essentially of a sheet of a thickness of 0.1-3 mm. of the photopolymerizable resin composition as claimed in claim 1.
Claim 4
Dependent Claim
26 words
A water-washable photopolymer printing plate having coated thereon a sheet of a thickness of 0.1-3 mm. of the photopolymerizable resin composition as claimed in claim 1.
Claim 5
Dependent Claim
44 words
A water-washable photopolymer printing plate consisting essentially of a sheet of a thickness of 0.1-3 mm. of the photopolymerizable resin composition as claimed in claim 1, a metal plate and an anchor layer inserted between the said resin composition and the said metal plate.
Claim 6
Dependent Claim
32 words
A photopolymer printing plate as claimed in claim 6, wherein the said anchor layer consists essentially of a single layer of a partially hydrolyzed polyvinyl acetate containing pigments having a nonhalation ability.
Claim 7
Dependent Claim
56 words
A photopolymer printing plate as claimed in claim 6, wherein the said anchor layer consists essentially of (1) a nonhalation layer and (2) a baked resin layer of a mixture of 29.6 parts by weight of a partially hydrolyzed polyvinyl acetate, 100 parts by weight of Beta -oxyethyl methacrylate and 1 part by weight of azobisisobutyronitrile.
Claim 8
Dependent Claim
106 words
A photopolymer printing plate as claimed in claim 6, wherein the said anchor layer consists essentially of (1) a nonhalation layer, (2) a baked resin layer of a mixture of 29.6 parts by weight of a partially hydrolyzed polyvinyl acetate, 100 parts by weight of Beta -oxyethyl methacrylate and one part by weight of azobisisobutyronitrile and (3) a layer of a mixture of seven parts by weight of uranyl nitrate, 29.6 parts by weight of a partially hydrolyzed polyvinyl acetate, 100 parts by weight of Beta -oxyethyl methacrylate and one part by weight of azobisisobutyronitrile, the said (3) layer being contacted with the photopolymerizable resin layer.
Claim 9
Dependent Claim
12 words
A photopolymerizable resin sheet formed of the composition defined in claim 1.