Process for surface treatment of flexographic printing plates containing butadiene/acrylonitrile copolymers
AssigneeE. I. Du Pont de Nemours and Compamy
InventorsMichael G. Fickes, Bohdan Rakoczy
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Abstract
Process for providing improved solvent resistant surfaces of relief flexographic printing plates prepared by imagewise exposure and liquid development of the unexposed areas of a layer of photosensitive elastomeric composition comprising a high molecular weight butadiene/acrylonitrile copolymer and a monomeric compound wherein, after drying, the developed surface is in either order (1) postexposed to actinic radiation, and (2) contacted with 0.01 to 3.5% by weight aqueous bromine solution for about 15 seconds to 20 minutes.
Claims5
A process for providing improved solvent resistant surfaces of relief flexographic printing plates wherein the reliefs are prepared by imagewise exposure with actinic radiation and liquid development of the unexposed areas of a layer of a photosensitive, elastomeric composition comprising a high molecular weight butadiene/acrylonitrile copolymer having a number average molecular weight of 20,000 to 75,000, an acrylonitrile content of 10 to 50% by weight and a carboxyl content of 0 to 15% by weight and a nongaseous ethylenically unsaturated compound containing at least one terminal ethylenic group, the improvement, wherein after drying, the developed surface is, in either order,
- (1) postexposed to a source of actinic radiation, and
- (2) contacted with an aqueous solution having a free bromine concentration of 0.01 to 3.5% by weight for about 15 seconds to 20 minutes.
Dependencies are inferred from the claim text.