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:
Aug. 11, 1992
Filed:
Jan. 25, 1991
Carl T Brozek, Webster, NY (US);
Robert C Daly, Greece, NY (US);
Robert H Fehnel, Rochester, NY (US);
Constantine C Petropoulos, Webster, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
A copolyester is synthesized by reacting a dialkyl ester of an aromatic dicarboxylic acid (e.g., dimethyl terephthalate) with ethylene glycol, low molecular weight poly(ethylene glycol) and a salt of a sulfonic acid-substituted aromatic dicarboxylate (e.g., sodium sulfoisophthalic acid) simultaneously in a first stage reaction in the presence of a phosphite or phosphate stabilizer. The intermediate product of the first stage is further reacted in a second stage in the presence of a polycondensation catalyst to obtain a random copolyester of the desired molecular weight. The copolyester is extruded to form a film which, after orientation and heat setting, has excellent clarity and is useful as a photographic film support. Aqueous processing of the film relaxes any core set or curl.