The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 1987
Filed:
Dec. 20, 1985
Katsuhiko Takahashi, Fuji, JP;
Polyplastics Co., Ltd., , JP;
Abstract
A polybutylene terephthalate is manufactured by the steps of polycondensating in the liquid phase terephthalic acid or a lower alcohol ester thereof as the acid component and 1,4-butanediol as the diol component to obtain a prepolymer of polybutylene terephthalate, solidifying the prepolymer and further polymerizing the prepolymer in the solid phase to obtain a polybutylene terephthalate of a higher polymerization degree, 0.001 to 5 percent by weight, based on the prepolymer, of a nucleator being added to the polymerization mixture at any time during a period of from the monomer-mixing stage before the starting of the solid phase polymerization, the solid phase polymerization being conducted in the presence of the nucleator uniformly dispersed in the polymerization mixture. The solid polymerization can be treated subsequently to the liquid polymerization and can proceed in a short time.