Patent ID: 7144973

Claim:
A biaxially oriented, white flame-retardant polyester film which comprises: (A) a polyester resin having an intrinsic viscosity of 0.4 to 0.9 dl/g which is composed of 60% by weight or more of ethylene terephthalate repeating units; (B) a flame-retardant which is alkylene bistetrabromophthalimide or decabromodiphenylalkane in an amount ranging from 5 to 18% by weight based on the weight of the resin; and (C) a fluorescent whitening agent in an amount ranging from 0.04 to 0.2% by weight based on the weight of the resin, said film being drawn at a total draw ratio (the sum of the longitudinal draw ratio and transverse draw ratio) of 9 or more.