Modacrylic fiber, flame-retardant fiber assembly containing same, and method for manufacturing same

Abstract

A modacrylic fiber includes a modacrylic polymer, a halogen-containing compound other than the modacrylic polymer, and a compound containing tin and zinc. The halogen-containing compound contains halogen in an amount of 50 mass % or more. The modacrylic fiber contains halogen in an amount of 40 mass % or more with respect to a total of 100 mass % of the modacrylic polymer and the halogen-containing compound. A molar ratio (halogen/tin) of halogen element derived from the modacrylic polymer and the halogen-containing compound to tin element derived from the compound containing tin and zinc is 32 or more.

1 . A modacrylic fiber comprising:
 a modacrylic polymer;   a halogen-containing compound other than the modacrylic polymer; and   a compound containing tin and zinc,   wherein the halogen-containing compound comprises halogen in an amount of 50 mass % or more,   the modacrylic fiber comprises halogen in an amount of 40 mass % or more with respect to a total of 100 mass % of the modacrylic polymer and the halogen-containing compound, and   a molar ratio (halogen/tin) of halogen element derived from the modacrylic polymer and the halogen-containing compound to tin element derived from the compound containing tin and zinc is 32 or more.   
     
     
         2 . The modacrylic fiber according to  claim 1 , wherein the compound containing tin and zinc comprises a zinc stannate compound. 
     
     
         3 . The modacrylic fiber according to  claim 1 , wherein the compound containing tin and zinc is zinc hydroxystannate. 
     
     
         4 . The modacrylic fiber according to  claim 1 , comprising the compound containing tin and zinc in an amount of 1 to 20 mass %. 
     
     
         5 . The modacrylic fiber according to  claim 1 , comprising the modacrylic polymer in an amount of 50 to 75 mass % and the halogen-containing compound in an amount of 25 to 50 mass % with respect to a total of 100 mass % of the modacrylic polymer and the halogen-containing compound. 
     
     
         6 . The modacrylic fiber according to  claim 1 , wherein the modacrylic polymer comprises acrylonitrile in an amount of 30 to 70 mass %, and a halogen-containing monomer in an amount of 30 to 70 mass %. 
     
     
         7 . The modacrylic fiber according to  claim 1 , wherein the halogen-containing compound comprises a polyvinyl chloride. 
     
     
         8 . The modacrylic fiber according to  claim 1 , wherein when the modacrylic fiber is combusted at 350° C. for 30 minutes, a tin (IV) halide is generated in an amount of 55 mass % or more and a tin (II) halide is generated in an amount of 45 mass % or less. 
     
     
         9 . A flame-retardant fiber composite comprising the modacrylic fiber according to  claim 1 . 
     
     
         10 . The flame-retardant fiber composite according to  claim 9 , wherein the compound containing tin and zinc comprises a zinc stannate compound. 
     
     
         11 . The flame-retardant fiber composite according to  claim 9 , wherein the compound containing tin and zinc is zinc hydroxystannate. 
     
     
         12 . The flame-retardant fiber composite according to  claim 9 , comprising the compound containing tin and zinc in an amount of 1 to 20 mass %. 
     
     
         13 . The flame-retardant fiber composite according to  claim 9 , comprising the modacrylic polymer in an amount of 50 to 75 mass % and the halogen-containing compound in an amount of 25 to 50 mass % with respect to a total of 100 mass % of the modacrylic polymer and the halogen-containing compound. 
     
     
         14 . The flame-retardant fiber composite according to  claim 9 , wherein the modacrylic polymer comprises acrylonitrile in an amount of 30 to 70 mass %, and a halogen-containing monomer in an amount of 30 to 70 mass %. 
     
     
         15 . The flame-retardant fiber composite according to  claim 9 , wherein the halogen-containing compound comprises a polyvinyl chloride. 
     
     
         16 . The flame-retardant fiber composite according to  claim 9 , wherein when the modacrylic fiber is combusted at 350° C. for 30 minutes, a tin (IV) halide is generated in an amount of 55 mass % or more and a tin (II) halide is generated in an amount of 45 mass % or less. 
     
     
         17 . The flame-retardant fiber composite according to  claim 9 , comprising tin derived from the modacrylic fiber in an amount of 1.4 mass % or more. 
     
     
         18 . The flame-retardant fiber composite according to  claim 9 , comprising the modacrylic fiber in an amount of 25 to 75 mass % and a cellulose fiber in an amount of 25 to 75 mass %. 
     
     
         19 . The flame-retardant fiber composite according to  claim 18 , wherein the cellulose fiber comprises a natural cellulose fiber. 
     
     
         20 . A method for producing the modacrylic fiber according to  claim 1 , the method comprising wet-spinning a spinning solution comprising the modacrylic polymer, the halogen-containing compound other than the modacrylic polymer, the compound containing tin and zinc, and a solvent.