Deproteinizing agent, deproteinized natural rubber latex using the same, and method of producing rubber product

Abstract

The present invention relates to (1) a deproteinizing agent for natural rubber latex, comprising a protease and one or more water-soluble polymers as an active component; (2) a deproteinized natural rubber latex, which is prepared by subjecting to a deprotenization treatment using the deproteinizing agent, and a method of producing the same; (3) a method of producing a rubber product, which comprises incorporating at least a vulcanizing agent into the latex (2), dipping a mold in the resulting compound latex, and vulcanizing and drying a rubber film formed on the mold; and (4) a method of producing a rubber product, which comprises incorporating at least a heat sensitizer and a vulcanizing agent into the latex (2), dipping a mold in the resulting heat-sensitive coagulable compound latex, and vulcanizing and drying a rubber film formed on the mold.

What is claimed is:  
     
         1 . A deproteinizing agent for natural rubber latex, comprising a protease and one or more water-soluble polymers as an active component.  
     
     
         2 . The deproteinizing agent according to    claim 1   , wherein the water-soluble polymer is a polymer having at least one hydrophilic functional group selected from a hydroxyl group, a carboxyl group, an amide group and an ester bond, or a salt thereof, a principal chain of the polymer having 100 to 5,000,000 carbon atoms.  
     
     
         3 . The deproteinizing agent according to    claim 1   , wherein a weight ratio of the protease to the water-soluble polymer is within a range from 1:1 to 1:200.  
     
     
         4 . A deproteinized natural rubber latex, which is prepared by subjecting to a deprotenization treatment using the deproteinizing agent of any one of    claims 1    to    3   .  
     
     
         5 . A method of producing a deproteinized natural rubber latex, which comprises adding the deproteinizing agent of any one of    claims 1    to    3    to a natural rubber latex, thereby maturing the natural rubber latex, and washing rubber particles in the latex.  
     
     
         6 . The method of producing a deproteinized natural rubber latex according to    claim 5   , wherein the amount of the deproteinizing agent is within a range from 0.001 to 10 parts by weight based on 100 parts by weight of the rubber solid content in the natural rubber latex.  
     
     
         7 . A method of producing a rubber product, which comprises adding a protease and one or more water-soluble polymers to a natural rubber latex, thereby subjecting the natural rubber latex to a deproteinization treatment, incorporating at least a vulcanizing agent into the latex, dipping a mold in the resulting compound latex, and vulcanizing and drying a rubber film formed on the mold.  
     
     
         8 . A method of producing a rubber product, which comprises adding a protease and one or more water-soluble polymers to a natural rubber latex, thereby subjecting the natural rubber latex to a deproteinization treatment, incorporating at least a heat sensitizer and a vulcanizing agent into the latex, dipping a mold in the resulting heat-sensitive coagulable compound latex, and vulcanizing and drying a rubber film formed on the mold.  
     
     
         9 . The method of producing a rubber product according to    claim 8   , wherein the heat sensitizer is a water-soluble polymer type heat sensitizer.  
     
     
         10 . The method of producing a rubber product according to    claim 7    or    8   , wherein the amount of the heat sensitizer is within a range from 0.1 to 10 parts by weight based on 100 parts by weight of the rubber solid content in the deproteinized latex.  
     
     
         11 . The method of producing a rubber product according to any one of    claims 7    to    10   , wherein the water-soluble polymer is a polymer having a bonding site due to at least one hydrophilic functional group selected from a hydroxyl group, a carboxyl group and an amide group and/or an ester bond, or a salt thereof, a principal chain of the polymer having 100 to 5,000,000 carbon atoms.