Copolyester.

摘要

A melt-processable copolyester comprising: (I) structural units of the formula (1), <CHEM> (II) structural units of the formula (2), -OC-X-CO- (2) wherein X is at least one group selected from <CHEM> (III) structural units of the formula (3) -O-Y-O- (3) wherein Y is at least one group selected from <CHEM> and (IV) structural units of the formula (4) -O-Z-O- (4) wherein Z represents at least one group selected from <CHEM> the content of structural units (IV) being 5 to 80 mole% of the total of structural units [(I)+(II)+(III)+(IV)], the total content of structural units [(I)+(II)] being substantially equimolar to the content of structural units (III), the content of structural units (I) being 10 to 90 mole% of the total of structural units [(I)+(II)], and the copolyester having an inherent viscosity (ln eta rel)/C, measured at a concentration of 0.16 g/dl in pentafluorophenol at 60 DEG C, of not less than 0.3 dl/g.