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:
Oct. 17, 2017
Filed:
Sep. 30, 2016
E I Du Pont DE Nemours and Company, Wilmington, DE (US);
Warren Francis Knoff, Richmond, VA (US);
Christopher William Newton, Richmond, VA (US);
E I DU PONT DE NEMOURS AND COMPANY, Wilmington, DE (US);
Abstract
The present invention concerns methods for obtaining high-tenacity aramid yarn, wherein the yarn is made of a copolymer obtained from a mixture of monomers comprising 5-(6)-amino-2-(p-aminophenyl)benzimidazole, an aromatic para-diamine, and an aromatic para-diacid; the method comprising: a) spinning said copolymer from an inorganic acid solvent to produce the aramid yarn; b) washing said yarn with a basic aqueous solution for at least 5 seconds; and c) heating said yarn; wherein the yarn is heated in at least two process steps, characterized in that (i) in a first step the yarn is heated at a temperature of 200 to 360° C. at a tension of at least 0.2 cN/dtex, followed by (ii) a second step wherein the yarn is heated at a temperature of 370 to 500° C. at a tension of less than 1 cN/dtex. In some embodiments, the yarn has an effective polymer cation to sulfur content molar ratio of at least 0.3. In some embodiments, the yarn has a hydrolytic strength retention of the yarn is greater than 60%.