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:
Apr. 16, 1985
Filed:
Jan. 31, 1984
Applicant:
Inventors:
Assignee:
Polyplastics Company, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ;
U.S. Cl.
CPC ...
528274 ; 528176 ; 528286 ; 560 94 ;
Abstract
Polytetramethylene terephthalate is manufactured from terephthalic acid and 1,4-butanediol in two stages, a first stage comprising an esterification reaction employing an esterification catalyst and a second stage comprising a condensation-polymerization reaction. The esterification reaction is carried out in the presence of at least one acid amide compound, preferably selected from urea, a derivative thereof, mono- or poly-carboxylic acid amides having 1 to 9 carbon atoms, polyamides, phosphoric acid amides and sulfonic acid amides, whereby the production of tetrahydrofuran as a by-product is appreciably inhibited and the time required for the esterification reaction is reduced.