Modified acrylonitrile polymer fibers with increased shrinkability and dyeability

Claim 1

METHOD OF PREPARING A DYE-RECEPTIVE AND HIGHLY SHRINKABLE SYNTHETIC ACRYLONITRILE POLYMER TEXTILE FIBER WHICH METHOD COMPRISES SALT SPINNING A FIBER-FORMING ACRYLONITRILE POLYMER THAT IS ADAPTED TO PROVIDE FIBERS WHICH DO NOT SHRINK MORE THAN 14 PERCENT AFTER EXPOSURE TO WATER AT ABOUT 100*C., WHICH POLYMER CONTAINS IN THE POLYMER MOLECULE AT LEAST ABOUT 80 WEIGHT PERCENT OF ACRYLONITRILE, ANY BALANCE BEING ANOTHER MONOETHYLENICALLY UNSATURATED MONOMERIC MATERIAL THAT IS COPOLYMERIZABLE WITH ACRYLONITRILE, INTO AN AQUAGEL FILAMENTARY STRUCTURE THAT CONTAINS BETWEEN ABOUT 1 AND 5 PARTS BY WEIGHT OF WATER TO EACH PART BY WEIGHT OF DRY POLYMER THEREIN, WASHING SAID AQUAGEL SUBSTANTIALLY FREE FROM RESIDUAL SALT AND PHYSICALLY ELONGATING SAID FIBER BY STRETCHING IT TO AN AT LEAST PARTIALLY ORIENTED CONDITION, SUBJECTING SAID AQUAGEL FIBER TO INTIMATE CONTACT WITH (A) AT LEAST ONE ALCOHOL SELECTED FROM THE GROUP CONSISTING OF TERTIARY ALCOHOLS AND BENZYL ALCOHOLS HAVING THE RESPECTIVE FORMULAE: