Patent ID: 9365952
Filing Date: 2016-06-14
CPC Classification: D01D,D01F

Claim Text:
1. A yarn comprising copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole, and terephthaloyl dichloride wherein the ratio of moles of 5(6)-amino-2-(p-aminophenyl)benzimidazole to the moles of para-phenyienediamine is 30/70 to 85/15, the yarn being spun from a dope comprising the copolymer and sulfuric acid; said yarn having a sulfur content greater than 0.1%; and said yarn having an Effective Polymer Cation to Sulfur Content Molar Ratio of at least 0.3 to about 2, wherein said where the symbols [Na], [Ca], [K], [Cl], and [S] are the concentration of these ions in moles/kilogram of polymer.