FORMING METHOD OF POLYESTER

摘要

Polyester is prepd. by reaction of dicarbon acid contg. terephthalic acid as main component and glycol contg. ethylene glycol as main component. In the process, the ethylene glycol ester and its lower polymeric polymer to be obtained in the step of esterification of the dicarbon acid with glycol, are satisfied in the condition of the formula (I) and (II); Φ = HV/(AV+HV) >= 0.85 (I), δ = (SV-AV)/SV >= 0.97 (II), where AV is the amt. of carboxyl terminal gp. in dry olygomer, HV is the amt. of hydroxyl terminal gp. in dry oligomer (eq/kg) and SV is gum value of dry oligomer. The polyester contains lower than 0.5% of the lower polymer of polymerization degree lower than 10.