Continuous production of elastic polyesters

摘要

An improvement in a process for producing an elastic polyester wherein a crystalline aromatic polyester and one or plurality of lactones are reacted, the improvement comprises by carrying out the reaction in a continuous process by continuously feeding the molten crystalline aromatic polyester and the lactones to a reaction vessel to subject them to addition polymerization, while continuously discharging a reaction mixture from the vessel to obtain the elastic polyester. Optionally, the reaction mixture can be further subjected to polycondensation in a molten state or a solid phase.