METHOD OF MANUFACTURING HIGH HEAT-RESISTANT THREADS FROM COPOLYAMIDOBENZIMIDAZOLE WITH REDUCED DEGREE OF SHRINKAGE Russian patent published in 2006 - IPC D01F6/74 C08G69/32 

FIELD: polymer production.

SUBSTANCE: invention relates to technology of manufacturing heat-resistant threads from aromatic polyamides, in particular copolyamidobenzimidazole, and can be used in manufacture of filter cloth for treating hot gases to remove toxic dust, in textile industry for sewing protective clothing for life-servers, firemen, oil and gas industry workers, and other those working in extremal situations, as well as for manufacturing carpet coverings and decorative and finishing fabrics. Method comprises synthesis of copolymer from mixture of 25-30 mol % 5(6)-amino-2-(4-aminophenyl)benzimidazole, 10-30 mol % p-phenylenediamine, and 40-60 mol % m-phenylenediamine per 100% terephthaloyl chloride in aprotic organic solvent in presence of LiCl or CaCl₂ until specific viscosity of copolymer in concentrated sulfuric acid achieves 1.2 to 2.0. p-Phenylenediamine is then added during cooling of resulting solution to 0-15°C. Thus obtained polycondensation solution is molded into water-organic bath to form thread, which is subjected to plasticizing stretching, rinsing, and drying.

EFFECT: simplified and reduced in price thread manufacturing process and reduced degree of shrinkage of thread.

5 cl, 1 tbl, 12 ex