公开(公告)号：JPS5521463A

公开(公告)日：1980-02-15

申请号：JP9478878

申请日：1978-08-03

Applicant: TORAY INDUSTRIES

Inventor： INOUE SHIYUNEI ,  ISHII SHIGENORI

IPC: C08G63/00 ,  C08G63/78

Abstract: PURPOSE:To prepare a polyester of high whiteness degree and uniform pigment dispersibility with reduced diethylene glycol content, by addition of a pigment after esterification, immediately followed by addition of ethylene glycol and then carrying out polycondensation under vacuum. CONSTITUTION:Bis-beta-hydroxyethylene terephthalate and/or its oligomer are(is) first prepared from terephthalic acid and ethylene glycol. Next, a pigment such as titanium dioxide, etc. is added, and then, within 10 minutes, ethylene glycol is added to the system in an amount of pref. 0.5-3wt% based on the polymer, immediately followed by carrying out polycondensation under vacuum to obtain the objective polyester.