METHOD FOR PRODUCING OF COPOLYAMIDOBENZIMIDAZOLE-BASED THREADS USING ALKALINE PROCESSING Russian patent published in 2007 - IPC D01F6/74 

FIELD: production of high-strength high-modulus threads, in particular, copolyamidobenzimidazole-based threads which may be used for reinforcement of plastics, technical rubber articles, fiber optics cables, as well as for creating of shell-proof jackets or safety helmets and other articles.

SUBSTANCE: method involves carrying-out low-temperature polycondensation synthesis of mixture of aromatic diamines of 5(6)-amino-,2-(para-aminophenyl) benzimidazole and paraphenylene diamine with terephthaloil chloride in amide solvent medium with salt admixture; providing wet or dry-wet forming from 4.0-5.1%-polycondensation solutions containing hydrogen chloride as by-product of polymer synthesis in aqueous-amide settling bath; washing resultant thread with water to remove solvent and providing alkaline processing of thread for neutralization of hydrogen chloride chemically bound with polymer and removal of produced chloride and excessive alkaline; finally washing thread with water and carrying-out drying, thermal processing and thermal draught; obtaining threads with neutral pH of aqueous extract after boiling process. Said threads have strength of up to 260 sN/tex, microplastic strength of up to 520 kgf/mm², modulus of elasticity of 15000-15300 kgf/mm², relative elongation at break of 2.6-3.3%.

EFFECT: improved strength characteristics of threads and wider range of usage.

4 cl, 4 ex