Antimicrobial agent and production process thereof

Abstract

An antimicrobial agent utilizes a resin having acrylonitrile and styrene and/or a conjugated diene as units. The antimicrobial agent includes a metal-salt-containing copolymer, and the metal-salt-containing copolymer is obtained by treating a copolymer containing acrylonitrile and at least one of styrene and a conjugated diene as units with an acid to thereby introduce acid radicals into the copolymer, and converting at least part of the acid radicals into a salt of at least one metal selected from among Ag, Cu, and Zn.

What is claimed is:  
     
         1 . An antimicrobial agent comprising a metal-salt-containing copolymer, said metal-salt-containing copolymer being obtained by treating a copolymer with an acid to thereby introduce acid radicals into said copolymer, said copolymer comprising acrylonitrile and at least one of styrene and a conjugated diene as units; and converting at least part of said acid radicals into a metal salt.  
     
     
         2 . An antimicrobial agent according to    claim 1   , wherein said metal-salt-containing copolymer is obtained by converting at least part of said acid radicals into a salt of at least one metal selected from the group consisting of Ag, Cu, and Zn.  
     
     
         3 . An antimicrobial agent according to    claim 1   , wherein said metal-salt-containing copolymer comprises 5 to 80% by mole of acrylonitrile.  
     
     
         4 . An antimicrobial agent according to    claim 1   , wherein said metal-salt-containing copolymer comprises 20 to 95% by mole of at least one of styrene and a conjugated diene.  
     
     
         5 . An antimicrobial agent according to    claim 1   , wherein said copolymer comprises at least one selected from the group consisting of acrylonitrile-butadiene-styrene resins, styrene-acrylonitrile resins, and acrylonitrile-butadiene rubbers.  
     
     
         6 . An antimicrobial agent according to    claim 1   , wherein said copolymer further comprises an inorganic pigment.  
     
     
         7 . An antimicrobial agent according to    claim 6   , wherein said inorganic pigment is at least one of carbon black and titanium dioxide.  
     
     
         8 . An antimicrobial agent according to    claim 6   , wherein said copolymer comprises 0.01 to 20% by weight of said inorganic pigment.  
     
     
         9 . An antimicrobial agent according to    claim 1   , wherein said copolymer comprises a spent resin.  
     
     
         10 . An antimicrobial agent according to    claim 1   , wherein said acid radicals are sulfonic acid groups.  
     
     
         11 . An antimicrobial agent according to    claim 1   , wherein said copolymer comprises 5 to 95% by weight of said acid radicals relative to the overall units of said copolymer.  
     
     
         12 . An antimicrobial agent comprising a metal-salt-containing copolymer, said metal-salt-containing copolymer being obtained by treating a copolymer with an acid to thereby introduce acid radicals into said copolymer, said copolymer containing acrylonitrile and at least one of styrene and a conjugated diene as units; and converting at least part of said acid radicals into a salt of at least one metal selected from the group consisting of Ag, Cu, and Zn.  
     
     
         13 . An antimicrobial agent according to    claim 12   , wherein said metal-salt-containing copolymer comprises 5 to 80% by mole of acrylonitrile.  
     
     
         14 . An antimicrobial agent according to    claim 12   , wherein said metal-salt-containing copolymer comprises 20 to 95% by mole of at least one of styrene and a conjugated diene.  
     
     
         15 . An antimicrobial agent according to    claim 12   , wherein said copolymer comprises at least one selected from the group consisting of acrylonitrile-butadiene-styrene resins, styrene-acrylonitrile resins, and acrylonitrile-butadiene rubbers.  
     
     
         16 . An antimicrobial agent according to    claim 12   , wherein said copolymer further comprises an inorganic pigment.  
     
     
         17 . An antimicrobial agent according to    claim 16   , wherein said inorganic pigment is at least one of carbon black and titanium dioxide.  
     
     
         18 . An antimicrobial agent according to    claim 16   , wherein said copolymer comprises 0.01 to 20% by weight of said inorganic pigment.  
     
     
         19 . An antimicrobial agent according to    claim 12   , wherein said copolymer comprises a spent resin.  
     
     
         20 . An antimicrobial agent according to    claim 12   , wherein said acid radicals are sulfonic acid groups.  
     
     
         21 . An antimicrobial agent according to    claim 12   , wherein said copolymer comprises 5 to 95% by weight of said acid radicals relative to the overall units of said copolymer.  
     
     
         22 . A process for producing an antimicrobial agent, comprising the steps of: 
 treating a copolymer with an acid to thereby introduce acid radicals into said copolymer, said copolymer containing acrylonitrile and at least one of styrene and a conjugated diene as units; and    converting at least part of said acid radicals into a salt of at least one metal selected from the group consisting of Ag, Cu, and Zn.    
     
     
         23 . A process according to    claim 22   , wherein a spent resin is used for the preparation of said copolymer.  
     
     
         24 . A process according to    claim 22   , wherein at least one inorganic acid selected from the group consisting of a concentrated sulfuric acid, sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, phosphoric acid, phosphorus chloride, and phosphorus oxide is used in said treating step.  
     
     
         25 . A process according to    claim 22   , wherein said copolymer is processed to a size of 3.5 mesh or less prior to said acid treatment.