POLYCONDENSATION SOLUTION OF COPOLYAMIDOBENZIMIDAZOLE TO FORM HIGH-STRENGTH THREADS WITH PARTIAL NEUTRALIZATION OF HYDROGEN CHLORIDE Russian patent published in 2006 - IPC D01F6/74 

FIELD: polymer materials.

SUBSTANCE: invention relates to technology of producing synthetic fibers from aromatic polymers and may be employed to reinforce plastics, mechanical rubber goods, and fiber-optics cables as well as to create armor and the like materials. Copolyamidobenzimidazole solution is prepared by low-temperature polycondensation of 50-80 mol % 5(6)-amino-2-(p-aminophenyl)benzimidazole and 20-50 mol % p-phenylenediamine with 100 mol % terephthaloyl chloride in dimethylacetamide or N-methylpyrrolidone as solvent with lithium chloride or calcium chloride as additive. Hydrogen chloride released from polymer synthesis is partly neutralized with reagents such as LiOH, LiOH·H₂O, Li₂CO₃, CaO, CaCO₃ so that level of hydrogen chloride in solution would be 0.2-0.9, which corresponds to molar ratio of residual HCl to benzimidazole cycles of polymer from 0.5 to 2.0.

EFFECT: increased strength and modulus of fibers.

2 cl, 1 tbl, 3 ex