Acrylic fiber and method for manufacturing same

Abstract

An acrylic fiber is composed of an acrylic polymer. The acrylic polymer includes acrylonitrile, wherein the acrylic fiber has a deformation degree of 0.13 or less and a surface roughness of 6000 μm 2 or less. A method for producing an acrylic fiber by wet spinning or dry-wet spinning includes: dissolving an acrylic polymer in an organic solvent to form a spinning solution, the acrylic polymer including acrylonitrile; discharging the spinning solution into a coagulation bath to form an acrylic fiber; water washing the acrylic fiber; and drying the acrylic fiber, wherein, before drying the acrylic fiber, the acrylic fiber is pressed with a nip roll and subjected to pre-drying using a dryer into which steam is fed.

What is claimed is: 
     
         1 . An acrylic fiber composed of an acrylic polymer, the acrylic polymer comprising acrylonitrile, wherein the acrylic fiber has a deformation degree of 0.13 or less and a surface roughness of 6000 μm 2  or less. 
     
     
         2 . The acrylic fiber according to  claim 1 , wherein the acrylic fiber has a deformation degree of 0.05 to 0.13 and a surface roughness of 3500 to 6000 μm 2 . 
     
     
         3 . The acrylic fiber according to  claim 1 , wherein the acrylic polymer comprises the acrylonitrile in an amount of 20 to 85 mass %, halogen-containing vinyl and/or halogen-containing vinylidene in an amount of 15 to 80 mass %, and a sulfonic acid group-containing monomer in an amount of 0 to 10 mass %, with respect to the total mass of the acrylic polymer. 
     
     
         4 . The acrylic fiber according to  claim 1 , wherein the acrylic fiber has a fineness of 10 to 100 dtex. 
     
     
         5 . A method for producing an acrylic fiber by wet spinning or dry-wet spinning, the method comprising:
 dissolving an acrylic polymer in an organic solvent to form a spinning solution, the acrylic polymer comprising acrylonitrile;   discharging the spinning solution into a coagulation bath to form an acrylic fiber;   water washing the acrylic fiber; and   drying the acrylic fiber,   wherein, before drying the acrylic fiber, the acrylic fiber is pressed with a nip roll and subjected to pre-drying using a dryer into which steam is fed.   
     
     
         6 . The method for producing an acrylic fiber according to  claim 5 , further comprising bath drawing the acrylic fiber by drawing the acrylic fiber in a drawing bath before or after water washing the acrylic fiber. 
     
     
         7 . The method for producing an acrylic fiber according to  claim 5 , wherein water washing the acrylic fiber comprises spraying water on the acrylic fiber and pressing with the nip roll the acrylic fiber on which water is sprayed. 
     
     
         8 . The method for producing an acrylic fiber according to  claim 5 , wherein the pre-drying is performed at a dry-bulb temperature of 100 to 160° C. and a wet-bulb temperature of 60 to 100° C. 
     
     
         9 . The method for producing an acrylic fiber according to  claim 5 , wherein the organic solvent in the spinning solution is at least one selected from the group consisting of dimethyl sulfoxide, dimethylacetamide, and N,N-dimethylformamide. 
     
     
         10 . The method for producing an acrylic fiber according to  claim 5 , wherein the coagulation bath comprises at least one organic solvent selected from the group consisting of dimethyl sulfoxide, dimethylacetamide, and N,N-dimethylformamide. 
     
     
         11 . The method for producing an acrylic fiber according to  claim 5 , wherein the acrylic polymer comprises the acrylonitrile in an amount of 20 to 85 mass %, halogen-containing vinyl and/or halogen-containing vinylidene in an amount of 15 to 80 mass %, and a sulfonic acid group-containing monomer in an amount of 0 to 10 mass %, with respect to the total mass of the acrylic polymer. 
     
     
         12 . The method for producing an acrylic fiber according to  claim 5 , wherein the acrylic polymer has a specific viscosity of 0.1 to 0.3. 
     
     
         13 . The method for producing an acrylic fiber according to  claim 5 , wherein the acrylic fiber has a fineness of 10 to 100 dtex after drying the acrylic fiber.