POLYESTER ELASTOMER RESIN COMPOSITION

PROBLEM TO BE SOLVED: To provide a polyester elastomer excellent in thermal degradation resistance, weathering resistance and water resistance, and to provide a master batch of an additive good in working aptitude. SOLUTION: A block polyester copolymer is obtained by reacting a polymer segment having a high melting point, which is composed of an acidic component mainly composed of an aromatic dicarboxylic acid and a glycol component mainly composed of an aliphatic and/or alicyclic dihydroxyl compound, with a polymer segment having a molecular weight of 400-4,000 and a low melting point. The thermoplastic polyester elastomer composition is composed of the polyester block copolymer of 100 pts.wt. and the additive of 10-50 pts.wt. wherein the following inequality is satisfied; (W1-W2)/W1≤0.7(%) (I) (wherein, W1 is a sample weight before heat treatment and W2 is the sample weight after heat treatment at 230°C and for 30 min). COPYRIGHT: (C)2003,JPO