Stretched film structure of the poly-1,3-phenylene terephthalate type.

摘要

A monoaxially or biaxially stretched film structure, or a heat-set structure thereof, of an unstretched film of an aromatic polyester having an intrinsic viscosity, determined in p-chlorophenol at 50°C, of 0.4 to 2.0 and composed of [A] polybasic carboxylic acid component units consisting of terephthalic acid units (a<Sub>1</Sub>) and units (a<Sub>2</Sub>) of a polybasic carboxylic acid otherthan terephthalic acid, the proportion of the units (a<Sub>2</Sub>) being up to 25 mole% based on the units (a,) and units (a<Sub>2</Sub>) combined, and [B] polyol component units consisting of resorcinol units (b<Sub>1</Sub>) and units (b<Sub>2</Sub>) of a polyol other than resorcinol, the proportion of the units (b<Sub>2</Sub>) being up to 25 mole% based on the units (b<Sub>1</Sub>) and (b<Sub>2</Sub>) combined.