Patent ID: 6884517
Filing Date: 2005-04-26
Classification: B29C,B29K,B32B,C08J,C08L,Y10S,Y10T

Abstract:
1. A biaxially oriented polyester film, comprising: at least a base layer made from polyester, wherein at least said base layer comprises from about 4 to about 50% by weight cycloolefin copolymer (COC) selected from the class consisting of norbornene-ethylene copolymers and tetracyclododecene-ethylene copolymers, and from about 0.1 to about 25% by weight of at least one white pigment, based on the weight of said layer, wherein said film in an uncoated state exhibits a gloss of more than about 10 when measured at an angle of 60°, where the glass transition temperature of the COC is within the range from about 110 to about 220° C., said polyester film containing from 10 to 70% regrind formed from said film, said film showing no increase in yellowness compared to film containing no regrind, at least said base layer further comprising an optical brightener, said optical brightener present in an amount ranging from 0.002 ppm to 5% by weight.