Patent ID: 6787218
Filing Date: 2004-09-07
Classification: B32B,Y10S,Y10T

Abstract:
A transparent, biaxially oriented polyester film with a base, layer B, at least 80% by weight of which consists essentially of a thermoplastic polyester, and with at least one outer layer A, wherein:the outer layer consiats essentially of a copolymer or of a mixture of homopolymers and copolymers, which contains ethylene 2,6-naphthalate units in a range of from 91 to 97% by weight and from 3% to 9% by weight of ethylene terephtbalate units, end/or units derived from cycloaliphatic or aromatic diols and/or dicarboxylic acids; the thickness of the outer layer A is more than 0.7 &mgr;m and makes up less than 25% by weight of the total film, and the Tg2 value of the polyester film is above the Tg2 value of the polyester for the base layer B but below the Tg52 value of the polyester for the outer layer A.