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:
May. 20, 1986
Filed:
Nov. 30, 1984
Philip G Kosky, Schenectady, NY (US);
Elizabeth A Guggenheim, Scotia, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
The molecular weight of linear polyesters such as poly(butylene terephthalate) and poly(ethylene terephthalate), especially the former, is increased by contacting a polyester having a maximum particle diameter of 1.0 and preferably 0.5 mm., with a mixture of an inert gas and an aliphatic diol such as 1,4-butanediol in the gaseous state at a temperature about 5.degree.-15.degree. C. below its equilibrium melting temperature, at a diol partial pressure of about 0.1-10 torr, to reduce the proportion of acid end groups; and subjecting the product thus obtained to solid state polymerization under vacuum. By this method, polyesters having a number average molecular weight of at least 100,000, useful for blow molding and the like, can be obtained.