PURPOSE: To make it possible to obtain a copolyester which is melt-moldable at a temperature ≤300°C and can give a molding excellent in heat resistance and hydrolysis resistance, by constituting it from bisphenoxyalkanedicarboxylic acid units, dihydroxybiphenyl units and hydroxybenzoic acid units.
CONSTITUTION: This melt-moldable polyester comprises bisphenoxyalkanedi- carboxylic acid units (A) of the formula (wherein n is 1W6), dihydroxybiphenyl units and dihydroxydiphenyl ether units (B) of the formula: -O-X-O- (wherein X is 4,4'-biphenylene or 4,4'-diphenyl ether group) and hydroxybenzoic acid units and 6-hydroxynaphthoic acid units (C) of the formula: -O-Y-O- (wherein Y is a 1,4-phenylene or 2,6-naphthylene), wherein the amount of units C is 10W80mol.% based on the whole the amount of units A and the amount of units B are substantially equimolar, and the inherent viscosity is 0.5dl/g or above when measured in a concentration of 0.16g/dl in pentafluorophenol at 60°C.
YAMAMOTO KOJI
HIROTA TOSHIZUMI
