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:
Dec. 16, 1997
Filed:
May. 31, 1996
Applicant:
Inventors:
Ramdas Dujari, Seaford, DE (US);
Daniel Gregory Tynan, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528310 ; 528313 ; 528322 ; 528335 ; 528336 ; 528337 ; 528487 ; 525419 ; 525420 ;
Abstract
A linear polyamide having a weight average molecular weight above 200,000 is made by heating a lower molecular weight molten polyamide with thorough mixing at a temperature of about 265.degree.-300.degree. C. for at least 5 minutes while an inert gas is swept gently through the reactor, the increase of molecular weight of the polyamide being catalyzed by a particular phosphinic acid derivative.