Patent ID: 9732442
Date: 2017-08-15
CPC Classifications: B29D,D01D,D01F

Claim:
1. A process for producing a yarn comprising the steps of: (a) producing a plurality of dope filaments by spinning a polymer solution through a multi-hole spinneret, the polymer solution being formed from sulfuric acid and a polymer in the form of a neutralized polymer crumb, said polymer comprising residues of 5(6)-amino-2-(p-aminophenyl)benzimidazole, terephthaloyl dichloride, and para-phenylenediamine; (b) coagulating the plurality of dope filaments into an as-spun yarn; (c) contacting the yarn with an aqueous base having a pKa less than or equal to 11; (d) rinsing the yarn; and (e) heating the yarn to a temperature of at least 350° C.