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US 5,674,623 AGranted
Photocurable film adhesives
AssigneeCiba-Geigy Corporation
InventorsMargaret Ruth Haddon, Terence James Smith
Life of this patent
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Abstract
A solid photocurable film adhesive comprising (I) a photocurable material having, on average, more than one acrylic group per molecule, at least 20% by weight of said material being a urethane acrylate, a polyester acrylate or a mixture of a urethane acrylate and a polyester acrylate, (II) as sole or major solid film-forming component, a solid polyvinylacetal and (III) a photoinitiator for photopolymerisation of acrylic compounds. The film adhesive is useful in the production of data-carrying laminates such as identity cards.
Claims24
A solid photocurable film adhesive comprising:
- (I) a photocurable material having, on average, more than one acrylic group per molecule consisting essentially of a mixture of (a)(i) a urethane acrylate having, on average, more than one acrylic group per molecule which is a reaction product of an isocyanate-terminated polyurethane prepolymer with a hydroxyl group-containing acrylic compound or (II) a polyester acrylate having, on average, more than one acrylic group per molecule which is a polyester modified after formation by reaction to introduce, on average, more than one acrylic group per molecule or (III) said urethane acrylate and said polyester acrylate with (b) a polyacrylic ester of an epoxide resin, at least 20% of said photocurable material being component (a),
- (II) as sole or major solid film-forming component, a solid polyvinylacetal present in an amount from 20 to 150% by weight of the photocurable material (I), and
- (III) a photoinitiator for photopolymerisation of acrylic compounds.
Dependencies are inferred from the claim text.