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:
Nov. 15, 1977
Filed:
Jan. 09, 1976
Yorihiko Omoto, Ehime, JA;
Tadashi Konishi, Matsuyama, JA;
Shigehiro Ichihara, Matsuyama, JA;
Hisanori Murai, Matsuyama, JA;
Teijin Limited, Osaka, JA;
Abstract
A process for preparing a polyester which comprises reacting a di-lower alkyl ester of a difunctional carboxylic acid at least 90 mole% of which consists of terephthalic acid with a polymethylene glycol containing 2 to 10 carbon atoms at least 90 mole% of which consists of ethylene glycol in the presence of an ester-interchange reaction catalyst to form an ester-interchange reaction product, and then polycondensing it in the presence of a polycondensation catalyst, wherein a substantially uniform solution in ethylene glycol of (A) 20 to 150 millimole%, based on said di-lower alkyl ester of the difunctional carboxylic acid, of calcium acetate and (B) 2 to 25 millimole%, based on said di-lower alkyl ester, of cobalt acetate is used as the ester-interchange reaction catalyst.