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:
Jan. 21, 2003
Filed:
Apr. 14, 2000
Richard Allen Hayes, Brentwood, TN (US);
David N Marks, Newark, DE (US);
Maria Van Eijndhoven, Wilmington, DE (US);
Hari Babu Sunkara, Wilmington, DE (US);
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process for producing polyamides from dinitriles and diamines in a continuous reaction using subsequent heating steps. In particular, the process involves contacting a dinitrile, a diamine, water, and optionally a catalyst to form a reaction mixture; heating the reaction mixture to a first elevated temperature of between about 180 to about 240° C., maintaining said temperature for about 0.10 to about 20 hours, and optionally controlling the pressure in this heating step by venting; heating the reaction mixture to a second elevated temperature of between about 250 to about 350° C., adding water to the reaction mixture before or after the second elevated temperature is reached, maintaining the pressure in the second heating step above atmospheric pressure by venting at least some of the water, and maintaining the second elevated temperature for a period of about 0.10 to about 10 hours; and recovering the polyamide.