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. 09, 1999
Filed:
Jun. 18, 1997
Chih-Pin Hsu, Kansas City, MO (US);
Ming-Yang Zhao, Kansas City, MO (US);
L Scott Crump, Gladstone, MO (US);
Cook Composites & Polymers Co., Kansas City, MO (US);
Abstract
An improved two-stage process for the preparation of polyester resins is provided which involves an initial reaction of a dicarboxylic acid such as isophthalic acid with an alkylene oxide such as ethylene or propylene oxide in the presence of a catalyst to form an oligoester reaction mixture, followed by a second stage reaction between the oligoester reaction mixture and a dibasic acid or anhydride; a first-stage catalyst is employed which has a thermal decomposition temperature substantially at or below the second-stage reaction temperature. The most preferred first-stage catalyst is benzyltriethylammonium chloride.