HEAT SHRINKABLE POLYESTER BASED FILM

摘要

PURPOSE:To obtain a heat shrinkable polyester based film slow in heat shrinkage proceeding and extremely reduced in occurrence of shrink spots by molding and drawing a composition obtained by blending a polyethylene terephthalate based polymer with a polyarylate. CONSTITUTION:The objective heat-shrinkable polyester based film extremely reduced in occurrence of shrink spots in heat shrinkage and pockmark-like crease is obtained by molding and drawing a polyester composition having 50-80 deg.C glass transition temperature and obtained by blending (A) a polyethylene terephthalate based polymer, preferably composed of a dicarboxylic acid component whose >=70mol% is terephthalic acid and a diol component whose >=70mol% is ethylene glycol and further combining other dicarboxylic acid component with other diol component so as to have 40-75 deg.C glass transition temperature with (B) a polyarylate, preferably a polycondensation product of bisphenol A and a dibasic acid (preferably terephthalic acid or isophthalic acid) and having 150-200 deg.C glass transition temperature.