Thermoplastic film for use in the manufacture of forgery-resistant identification documents
AssigneeHoechst Aktiengesellschaft
InventorsHermann Dallmann, Hans J. Palmen
Life of this patent
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Abstract
A thermoplastic protective film for use in the manufacture of forgery-resistant identification documents, comprising a base layer and a cover layer comprising a partially hydrolyzed olefin/vinyl ester copolymer. The cover-layer side of the film is laminated under the action of heat to the identification document.
Claims26
A forgery-resistant identification document comprising a core carrying identifying information, said core having laminated thereto the cover layer side of a thermoplastic protective film comprising a base layer and a cover layer comprising a partially hydrolyzed olefin/vinyl ester copolymer, the degree of hydrolysis of said copolymer lying in the range from 20 to 99 percent, said laminated protective film being impossible to detach from said document at temperatures up to and as high as 120.degree. C. without destroying said document.
A method of protecting an identification document against forgery comprising laminating to said document the cover layer side of a thermoplastic protective film comprising a base layer and a cover layer comprising a partially hydrolyzed olefin/vinyl ester copolymer, the degree of hydrolysis of said copolymer lying in the range from 20 to 99 percent, said laminated protective film being impossible to detach from said document at temperatures up to and as high as 120.degree. C. without destroying said document.
Dependencies are inferred from the claim text.