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. 18, 1997
Filed:
Oct. 21, 1996
Applicant:
Inventor:
Kamlesh Kumar Bhatia, Newark, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ; C08F / ;
U.S. Cl.
CPC ...
528272 ; 528272 ; 528298 ; 528302 ; 528307 ; 528308 ; 5283086 ; 528486 ; 528491 ; 528492 ; 528503 ; 525437 ; 525444 ;
Abstract
An atmospheric pressure process for the continuous production of polyester is disclosed wherein a melt of bis(3-hydroxy propyl) terephthalate, or its low molecular oligomers, obtained by esterifying terephthalic acid or transesterifying dimethyl terephthalate with propylene glycol, is intimately contacted with an inert gas to facilitate polymerization and removal of the reaction by-products. The propylene glycol evolved and the inert gas are recycled.