Process for producing new polyester resin and product thereof

摘要

A new polyester resin is produced by condensation polymerization of (a) a diol component of the formula: <IMAGE> (I) wherein R1 is an alkylene group of 2 to 4 carbon atoms; and x and y are positive integers, the sum of them being 2 to 16 on an average, and (b) an acid component of polybasic (at least dibasic) carboxylic acid, anhydride thereof, and lower alkyl ester thereof, said acid component (b) containing 1 to 50 mol % of a dibasic carboxylic acid or anhydride thereof of the formula: <IMAGE> where R2 and R3 are saturated or unsaturated hydrocarbon groups of 4 to 20 carbon atoms and 10 to 30 mol % of trimellitic acid or anhydride thereof. The polyester has improved toughness, abrasion resistance and flexibility.