BLOCK COPOLYESTER, PROCESS FOR THE PRODUCTION THEREOF AND COMPOSITIONS CONTAINING THE SAME

摘要

A block copolyester which is excellent in heat resistance and elastic recovery and exhibits a stable melting point in melting and which is useful as a polyester elastomer. This copolyester is characterized in that both the main acid component of the soft segment and that of the hard segment are terephthalic acid. The block copolyester gives a composition having the above excellent characteristics and being excellent in vibration-damping properties, when blended with polytetramethylene terephthalate, while it gives a composition excellent in transparency, when blended with sodium salts of certain acids, such as sodium montanate.