Method for producing acrylic fiber

Abstract

A method for producing acrylic fiber includes preparing a spinning solution including an acrylic copolymer, dimethyl sulfoxide, water, and a polyphosphate; and subjecting the spinning solution to wet spinning, wherein the acrylic copolymer includes acrylonitrile in an amount of 20 to 85 mass %, vinyl chloride in an amount of 14.5 to 79.5 mass %, and a sulfonic acid group-containing monomer in an amount of 0.5 to 10 mass % with respect to a total mass of the acrylic copolymer.

What is claimed is: 
     
         1 . A method for producing acrylic fiber, comprising:
 preparing a spinning solution comprising an acrylic copolymer, dimethyl sulfoxide, water, and a polyphosphate; and   subjecting the spinning solution to wet spinning,   wherein the acrylic copolymer comprises acrylonitrile in an amount of 20 to 85 mass %, vinyl chloride in an amount of 14.5 to 79.5 mass %, and a sulfonic acid group-containing monomer in an amount of 0.5 to 10 mass % with respect to a total mass of the acrylic copolymer.   
     
     
         2 . The method for producing acrylic fiber according to  claim 1 , wherein the spinning solution comprises the polyphosphate in an amount of 0.05 to 5 mass % with respect to the total mass of the acrylic copolymer. 
     
     
         3 . The method for producing acrylic fiber according to  claim 1 , wherein the polyphosphate is at least one compound selected from the group consisting of a pyrophosphate, a tripolyphosphate, a tetrapolyphosphate, a trimetaphosphate, and a tetrametaphosphate. 
     
     
         4 . The method for producing acrylic fiber according to  claim 2 , wherein the polyphosphate is at least one compound selected from the group consisting of a pyrophosphate, a tripolyphosphate, a tetrapolyphosphate, a trimetaphosphate, and a tetrametaphosphate. 
     
     
         5 . The method for producing acrylic fiber according to  claim 3 , wherein the polyphosphate is a tripolyphosphate. 
     
     
         6 . The method for producing acrylic fiber according to  claim 4 , wherein the polyphosphate is a tripolyphosphate.