META-AROMATIC POLYAMIDE FIBRE WITH EXCELLENT PROCESSING PROPERTIES AT HIGH TEMPERATURE AND PRODUCTION METHOD THEREOF Russian patent published in 2011 - IPC D01F6/60 D01F6/74 D01D5/06 D01D10/02 C08G69/02 D01F11/08 

FIELD: chemistry.

SUBSTANCE: fibre is obtained via wet spinning of a solution which contains poly-meta-phenyleneisophthalamide as the main component, and an amide solvent containing a salt in settling bath. The water coagulation bath contains 40-60% amide solvent and 0.3-10% salt. The obtained porous fibre is stretched 1.5-10 times in a stretch bath with aqueous 20-70% solution of amide solvent at 20-70°C and then washed with water. The fibre then undergoes thermal treatment in an atmosphere of saturated vapour at 0.02-0.5 MPa with stretch ratio of 0.7-5.0 and then undergoes dry thermal treatment at 250-400°C with stretch ratio of 0.7-4.0. The ready fibre contains 1.0% or residual solvent, a small amount of volatile substance which is dangerous at the step for thermal treatment at high temperature, and capable of preventing dyeing of the product made from the fibre. The degree of dry thermal setting at 300°C is equal to or less than 1.6% and breaking strength is equal to or more than 3.0 cN/decitex.

EFFECT: excellent high-temperature processability.

11 cl, 1 tbl, 6 ex