Polymer composition for conductive roller, polymer composition, conductive roller, and conductive belt

Abstract

A polymer composition for a conductive roller composed of a rubber component whose main component is an epichlorohidrin rubber containing ethylene oxide at not less than 55 mol % nor more than 95 mol %. Thioureas are added to 100 g of the rubber component as a crosslinking agent at a rate not less than 0.014 mol nor more than 0.080 mol. In a compression set test of a vulcanized rubber described in JIS K6262, a compression set measured at 70° C. for 22-24 hours is less than 15%; and in a volume resistivity value test described in JIS K6911, a volume resistivity value measured at an applied voltage of 1000V is less than 10 7.5 [Ω·cm].

What is claimed is:  
     
         1 . A polymer composition for a conductive roller composed of a rubber component whose main component is an epichlorohidrin rubber containing ethylene oxide at not less than 55 mol % nor more than 95 mol %, 
 wherein in a compression set test of a vulcanized rubber described in JIS K6262, a compression set measured at 70° C. for 22-24 hours is less than 15%; and in a volume resistivity value test described in JIS K6911, a volume resistivity value measured at an applied voltage of 1000V is less than 10 7.5 [Ω·cm].    
     
     
         2 . The polymer composition for a conductive roller according to  claim 1 , wherein said ethylene oxide is contained at not less than 55 mol % nor more than 95 mol % for 100 mol % of said rubber component.  
     
     
         3 . The polymer composition for a conductive roller according to  claim 1 , wherein thioureas are added to 100 g of said rubber component as a crosslinking agent at a rate not less than 0.014 mol nor more than 0.080 mol.  
     
     
         4 . The polymer composition for a conductive roller according to  claim 1 , wherein said rubber component does not contain a zinc compound.  
     
     
         5 . The polymer composition for a conductive roller according to  claim 1 , wherein zinc oxide is added to 100 parts by weight of said rubber component as a crosslinking assistant at a rate not less than 0.1 parts by weight nor more than 20.0 parts by weight.  
     
     
         6 . The polymer composition for a conductive roller according to  claim 1 , wherein as said thioureas, one or a plurality of thioureas selected from among a group consisting of tetramethylthiourea, trimethylthiourea, ethylene thiourea, and (C n H 2n+1 NH) 2 C═S (n=integers 1-10) is used.  
     
     
         7 . The polymer composition for a conductive roller according to  claim 3 , wherein said thioureas are contained as a master batch.  
     
     
         8 . The polymer composition for a conductive roller according to  claim 7 , wherein said master batch of said thioureas contains an acrylic resin as a binder.  
     
     
         9 . A conductive roller having an elastic layer formed by molding the polymer composition for a conductive roller according to  claim 1 .  
     
     
         10 . A polymer composition containing a polymer having carbon-to-carbon double bonds and a halogen as a main component thereof and containing sulfur and thioureas.  
     
     
         11 . The polymer composition according to  claim 10 , wherein as said polymer having carbon-to-carbon double bonds and said halogen, epichlorohidrin-ethylene oxide-allyl glycidyl ether copolymer and/or a chloroprene rubber are used; and 
 as said thioureas, one or a plurality of thioureas selected from among a group consisting of tetramethylthiourea, trimethyithiourea, ethylene thiourea, and (C n H 2n+1 NH) 2 C═S (n=integers 1-10) is used.    
     
     
         12 . The polymer composition according to  claim 10 , wherein said thioureas are added to 100 g of an entire polymer component at a rate not less than 0.0009 mol % nor more than 0.0800 mol %.  
     
     
         13 . The polymer composition according to  claim 10 , wherein said sulfur is added to 100 parts by weight of an entire polymer component at a rate not less than 0.1 parts by weight nor more than 5.0 parts by weight.  
     
     
         14 . The polymer composition according to  claim 10 , wherein a guanidine accelerator is contained in combination with said thioureas.  
     
     
         15 . The polymer composition according to  claim 10 , wherein a zinc compound is not contained.  
     
     
         16 . The polymer composition according to  claim 10. , wherein zinc oxide is added to 100 parts by weight of an entire polymer component at a rate not less than 0.1 parts by weight nor more than 20.0 parts by weight.  
     
     
         17 . The polymer composition according to  claim 10 , wherein said thioureas are contained as a master batch.  
     
     
         18 . The polymer composition according to  claim 17 , wherein said master batch of said thioureas contains an acrylic resin as a binder.  
     
     
         19 . A conductive roller using the polymer composition according to  claim 10 .  
     
     
         20 . A conductive belt using the polymer composition according to  claim 10 .  
     
     
         21 . A polymer composition for a conductive roller containing a polymer having carbon-to-carbon double bonds and a halogen as a main component thereof and containing a chemical foaming agent, sulfur, and thioureas.  
     
     
         22 . The polymer composition according to  claim 21 , wherein as said polymer having carbon-to-carbon double bonds and said halogen, epichlorohidrin-ethylene oxide-allyl glycidyl ether copolymer and/or a chloroprene rubber are used; and 
 as said thioureas, one or a plurality of thioureas selected from among a group consisting of tetramethylthiourea, trimethylthiourea, ethylene thiourea, and (C n H 2n+1 NH) 2 C═S (n=integers 1-10) is used.    
     
     
         23 . The polymer composition for a conductive roller according to  claim 21 , wherein said chemical foaming agent is a hydrazine derivative.  
     
     
         24 . The polymer composition for a conductive roller according to  claim 23 , wherein said hydrazine derivative is 4,4′-oxybis (benzene sulfonyl hydrazide).  
     
     
         25 . The polymer composition for a conductive roller according to  claim 21 , wherein said thioureas are added to 100 g of an entire polymer component at a rate not less than 0.0009 mol nor more than 0.0800 mol; and 
 said sulfur is added to 100 parts by weight of said entire polymer component at a rate not less than 0.1 parts by weight nor more than 5.0 parts by weight; and said chemical foaming agent is added to 100 parts by weight of said entire polymer component at a rate not less than 0.5 parts by weight nor more than 20 parts by weight.    
     
     
         26 . A conductive roller composed of the polymer composition for a conductive roller according to  claim 21 .  
     
     
         27 . A polymer composition for a conductive roller containing a polymer having carbon-to-carbon double bonds and a halogen as a main component thereof and containing a chemical foaming agent, sulfur, triazine and/or a derivative thereof.  
     
     
         28 . The polymer composition for a conductive roller according to  claim 27 , wherein as said polymer having carbon-to-carbon double bonds and said halogen, epichlorohidrin-ethylene oxide-allyl glycidyl ether copolymer and/or a chloroprene rubber are used; and 
 as said triazine and/or said derivative thereof, one or a plurality of triazines selected from among a group consisting of 2,4,6-trimelcapto-S-triazine and 2-dialkylamino-4,6-dimelcapto-S-triazine are used.    
     
     
         29 . The polymer composition for a conductive roller according to  claim 27 , wherein said chemical foaming agent is a hydrazine derivative.  
     
     
         30 . The polymer composition for a conductive roller according to  claim 29 , wherein said hydrazine derivative is 4,4′-oxybis (benzene sulfonyl hydrazide).  
     
     
         31 . The polymer composition for a conductive roller according to  claim 27 , wherein magnesium oxide is contained.  
     
     
         32 . The polymer composition for a conductive roller according to  claim 31 , wherein said triazine and/or said derivative thereof are added to 100 g of an entire polymer component at a rate not less than 0.0004 mol nor more than 0.0500 mol; and 
 said sulfur is added to 100 parts by weight of said entire polymer component at a rate not less than 0.1 parts by weight nor more than 5.0 parts by weight; said chemical foaming agent is added to 100 parts by weight of said entire polymer component at a rate not less than 0.5 parts by weight nor more than 20 parts by weight; and said magnesium oxide is added to 100 parts by weight of said entire polymer component at a rate not less than 0.2 parts by weight nor more than 15 parts by weight.    
     
     
         33 . A conductive roller composed of the polymer composition for a conductive roller according to  claim 27.