Patent ID: 6589384
Filing Date: 2003-07-08
Classification: C08G,C09J,H01L,Y10S,Y10T

Abstract:
A method of laminating a first film of polymeric material to a second film of polymeric material comprising:(a) providing, in molten form, a solventless, hydroxyl-terminated polyester A) formed from a single species of a linear aliphatic diol having terminal hydroxyl groups and having from 2 to 10 carbons and a single species of a linear dicarboxylic acid, said polyester having a number average molecular weight from about 300 to about 5000 and a melting point of 80Â° C. or below, (b) providing, in liquid form, a single species of diisocyanate B), either (c) mixing said diisocyanate B) and said polyester A) at an NCO/OH ratio of between about 1 and 1.1 to form an adhesive mixture (I), or reacting all of or a portion Bâ€²) of said diisocyanate B) with a portion Aâ€²) of said polyester A) at an NCO/OH ratio of between about 2 and 8 to form a urethane prepolymer C) and mixing the remaining portion Aâ€³) of said polyester A) and any remaining portion Bâ€³) of said diisocyanate B) with said urethane prepolymer C) to form an adhesive mixture (II), the NCO/OH ratio of A) to B) being between about 1 and 1.1, (d) applying either of the adhesive mixture (I) or (II) to one of said first or second films, said adhesive mixture being prepared just prior to application to said film, (e) contacting and adhering said films such that crystalline polyester domains are formed prior to substantial cure of said mixture and attendant polyurethane adhesive formation, and (f) allowing said diisocyanate B) and said polyester A) to fully react, thereby forming an adhesive layer having high gas barrier properties.