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:
Sep. 02, 1997
Filed:
Jul. 30, 1996
Applicant:
Inventor:
Edward Gus Brugel, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528272 ; 528176 ; 528190 ; 528191 ; 528192 ; 528193 ; 528194 ; 528271 ;
Abstract
An improved process for preparing high molecular weight polyester polymers, such as poly(butylene terephthalate), an alkylene glycol and a di- or tricarboxylic acid by first preparing a pre-polymer in the form of uniform solid particles having an intrinsic viscosity of from 0.1 to about 0.3 dL/gm and a chemical composition which contains greater than a 1% stoichiometric excess of the alkylene glycol above the amount required to produce a high molecular weight polymer, and polymerizing the pre-polymer in the solid state.