BIAXIALLY ORIENTED PARAPHENYLENE SULFIDE BLOCK COPOLYMER FILM AND PROCESS FOR PRODUCING THE SAME

摘要

Disclosed herein is a biaxially oriented paraphenylene sulfide block copolymer film showing a heat shrinkage of 0 - 2.0% at 100 - 220.degree.C, comprising a paraphenylene sulfide block copolymer essentially composed of recurring units (A): and recurring units (B): , the molar fraction of recurring units (A) being 0.50 - 0.98, and having a melt viscosity (?*) of 1,000 - 15,000 poises as measured at 310.degree.C and shear rate of 200 sec-1, a glass transition temperature (Tg) of 20 80.degree.C, a crystalline melting point (Tm) of 250 - 285.degree.C and a crystallization index (Ci) of 15 - 45 (measured with the non-stretched heat-treated polymer film), and a process for producing the biaxially oriented paraphenylene sulfide block copolymer film.