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. 11, 1979
Filed:
Feb. 27, 1978
Applicant:
Inventor:
Wesley Memeger, Jr, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08J / ;
U.S. Cl.
CPC ...
521 89 ; 260 302 ; 260 / ; 260 / ; 521 98 ; 521184 ; 528336 ;
Abstract
Aromatic polyamide foams having a density of 0.025 to 0.7 g./cm..sup.3 are prepared by heating N,N'-dialkyl aromatic polyamides having at least one .beta. hydrogen atom on the alkyl groups, a plasticizer and an aromatic sulfonic acid catalyst at 250.degree. to 340.degree. C. for a length of time sufficient to remove substantially all of the N-alkyl groups.