METHOD FOR PRODUCING POLYOXADIASOLE THREADS Russian patent published in 2022 - IPC D01F6/74 D01D10/02 D01D10/06 D01D1/02 

FIELD: chemical fibers production.

SUBSTANCE: invention relates to a technology for the production of chemical fibers, in particular to the production of polyoxadiazole yarns, and is intended for use in the manufacture of heat-resistant materials and products. A method for producing a polyoxadiazole yarn, which includes obtaining a polymer spinning solution by polycondensation by heating hydrazine sulfate with arylenedicarboxylic acid in an oleum medium, its homogenization, filtration, degassing, spinning, precipitation in a sulfuric acid aqueous precipitation bath, plasticizing drawing of the formed yarn, pressing, washing, neutralizing traces acid and heat treatment, according to the invention, the polycondensation is carried out to obtain a spinning solution having a cyclization degree of 100%, while the spinning is carried out in two phases, the first of which is carried out through the holes of the spinneret into the gaseous medium in a downward direction over 20-30 mm, and the second phase molding is carried out in a precipitation bath for at least 800 mm, and the plasticization ratio is 3÷5, and heat treatment is carried out at a temperature of 350-400°C for 3-5 s, while the resulting thread has the following physical and mechanical characteristics: specific strength 45-55 cN /tex, elongation at break 3.5-5.5%, modulus of deformation 12-16 GPa, electrical resistance 10^-10-10^-11Ohm×mm²/m, equilibrium humidity 14%, frost resistance not lower than -70°C , shrinkage 0%.

EFFECT: improvement of the physical and mechanical properties of the thread, such as non-shrinkage, increased mechanical strength, equilibrium moisture content, reduced relative elongation and electrical resistance, high frost resistance.

3 cl, 3 ex