Photocrosslinkable compositions for screen printing stencils
AssigneeArthur D. Little, Inc.
InventorsRichard E. Merrill, Arthur A. Massucco
Life of this patent
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Abstract
Screen printing stencils are prepared by afixing to a printing screen substrate an indicia-defining, ultraviolet-sensitive film and cross-linking the film by exposure to ultraviolet radiation. The coating compositions used to form the film comprise copolyacrylate/polyurethane block copolymers, in which the copolyacrylate blocks are copolymers of at least one hydroxy-containing acrylate and at least one acrylate or methacrylate which may be partially substituted with bromine, ultraviolet initiators and cross-linking monomers. Screen printing stencils are provided which are compatible with both water-based and oil-based inks. The disclosed screen printing stencils are used in improved screen-printing methods.
Claims25
An article of manufacture suitable for use in the formation of screen printing stencils, comprising in combination
- (a) a temporary support;
- and
- (b) an ultraviolet cross-linkable film removably affixed to said temporary support, said film comprising a uv-initiated crosslinking promoter, an ultraviolet initiator, and a block copolymer formed of blocks of a copolyacrylate and a polyurethane, said copolyacrylate comprising a copolymer of a hydroxy-containing acrylate and a second acrylate component which comprises one or more esters of a non-hydroxy-containing acrylic acid or methacrylic acid or mixtures thereof;
- said film in its cross-linked form being further characterized as resistant to both water-based and oil-based printing inks.
A liquid coating composition suitable for forming an ultraviolet-cross-linkable film on a substrate, comprising
- (a) a block copolymer formed of blocks of a copolyacrylate and a polyurethane, said copolyacrylate comprising a copolymer of a hydroxy-containing acrylate and a second acrylate component which comprises one or more esters of a non-hydroxy-containing acrylic acid or methacrylic acid or a mixture thereof;
- (b) a solvent for said block copolymer;
- (c) an ultraviolet initiator, and
- (d) at least one cross-linking promoter.
Dependencies are inferred from the claim text.