Lithographic printing plate having dual photosensitive layering
AssigneePolychrome Corporation
InventorPaul Jargiello
Life of this patent
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Abstract
A method for preparing aluminum based lithographic printing plates which comprises treating at least one surface of an aluminum base sheet with lithographically suitable, photosensitive, preferably water-soluble, diazo composition and then applying to said surface a lithographically suitable photopolymerizable composition to yield the desired photosensitive lithographic printing plate of improved characteristics.
Claims7
A lithographic printing plate capable of development with an aqueous alkali developer which comprises a sheet substrate having coated thereon a light-sensitive, lithograhically suitable, water-soluble diazo composition, said diazo composition having coated thereon a lithographically suitable photopolymerizable composition, which photopolymerizable composition comprises the admixture of, in percent by weight of the photopolymerizable composition:
- (a) an acrylonitrile butadiene styrene resin in an amount of from 2% to 25%;
- and
- (b) one or more resins selected from the group consisting of solid acrylic, polyurethane and polyamide resins in an amount of from 4% to 50%;
- and
- (c) cellulose acetate phthalate in an amount of from 4% to 50%;
- and
- (d) one or more ethylenically unsaturated monomeric or oligomeric compounds having on the average, more than one double bond, and being capable of forming a high polymer by free radical addition photopolymerization, in an amount of from 20% to 60%;
- and
- (e) a photoinitiator capable of generating free radicals in an amount of from 0.5% to 45%;
- and
- (f) p-phenol sulfonic acid sodium salt in an amount of from 0.4% to 5%.
Dependencies are inferred from the claim text.