LOW MELTING POINT COPOLYESTER AND PROCESS FOR PREPARING THE SAME

摘要

A copolyester having a broad amorphous region is disclosed, which is prepared from terephthalic acid, isophthalic acid and a dibasic alcohol component as well as an ether bond-containing dihydroxy compound as basic materials, wherein the acid component comprises 10-30 mol% isophthalic acid and 70-90 mol% terephthalic acid, by the steps of: formulating the components in a molar ratio of total acid/total alcohol equal to 1.05-2.0 to obtain an uniform slurry, followed by esterification and polycondensation reaction, to thereby result in a low melting point copolyester without obvious melting peak, and having a broad amorphous region, as determined by DSC. The process of the present invention can be put into industrial production by using the existing semi-continuous and continuous production lines of polyester. The polyester prepared by the process of the present invention can be used for the production of packaging film, sheet, hot-melt adhesive, and etc. It is especially suitable for making heat shrinkable film for use as packaging material or as label, to substitute polyvinyl chloride (PVC) film presently used in the market.