The invention concerns a novel melt-processible copolyester and a process and prepolymer for the preparation thereof. The copolyester contains structural units derived from a polyester and structural units derived from diepoxy, and the polyester units at least essentially consist of hydroxy acid monomers. The bonds between the structural units are ester bonds and the number average molar mass, Mn, is at least 10,000 g/mol, its weight average molar mass, Mw, is over 20,000 g/mol and molar mass distribution, expressed as the ratio Mw/Mn, is over 2. The copolyester is hydrolytically degradable and it can be used as a biodegradable polymer for the manufacture of injection moulded articles as well as thermoformed and blow moulded packages, pouches, sacks and bottles, for the coating of sacks bags and films made from paper or cardboard and for the preparation of fibres, fibre cloths and expanded polymer articles.
|IPC||C09J 167/ 04 A I|
|Publication status||Published - 10 Oct 1996|
|MoE publication type||H1 Granted patent|