Copolyester resin composition and a process of preparation thereof

Abstract

The present invention provides a copolyester resin composition which has good physical properties, biodegradability and processability and a process for preparing and/or producing the same. To improve the biodegradability and physical properties of the copolyester, the present invention applied multi-stage reaction step, and copolyester resin having number average molecular weight of from 30,000 to 70,000, weight average molecular weight of from 100,000 to 600,000, melting point of from 55° C. to 120° C., and melt index of from 0.1 to 30 g/10 minute (190° C., 2,160 g) is obtained. The processability and physical properties of the copolyester resin of the present invention has been greatly enhanced by incorporating (i) an “aromatic-aliphatic prepolymers” having number average molecular weight of from 300 to 30,000 and the contiguous repeating unit of aromatic group in the dicarboxylic acid position of “aromatic-aliphatic prepolymers” is less than 5. Thus it can be processed by using the conventional processing equipment for polyethylene and polypropylene without any modification.

Dependencies are inferred from the claim text.