Rubber composition for aircraft tire treads

Abstract

Tire treads, especially tire treads for aircraft or for heavy vehicles, formed from a material that is based upon a cross-linkable rubber composition, the cross-linkable rubber composition comprising, per 100 parts by weight of rubber, between 40 phr and J 00 phr of a polyisoprene rubber, between 0 and 60 phr of a highly unsaturated diene rubber and between 1 phr and 25 phr of a polylerpene resin having a glass transition temperature of between 50° C. and 120° C. The rubber composition further includes between 0.1 phr and 10 phr of a poly-thiosulfate anti-reversion agent having the formula: MO 3 S—S—X—S—SO 3 M wherein X is an alkylene radical or a radical comprising two or more alkylene units, pairs of which units being linked through an oxygen or a sulfur atom, through a group SO 2 —, —NH—, —NH 2 + —, —NlC 1 - 16 alkyl)- or —COO—, or through an arylene or cycloalkylene radical and M is a metal.

1 . An aircraft tire tread formed from a material that is based upon a cross-linkable rubber composition, the cross linkable rubber composition comprising, per 100 parts by weight of rubber:
 between 40 phr and 100 phr of a polyisoprene rubber;   between 0 and 60 phr of a highly unsaturated diene rubber;   between 1 phr and 25 phr of a polyterpene resin having a glass transition temperature of between 50° C. and 120° C.; and   between 0.1 phr and 10 phr of a poly-thiosulfate anti-reversion agent having the formula:
   MO 3 S—S—X—S—SO 3 M
 
   
       wherein X is an alkylene radical or a radical comprising two or more alkylene units, pairs of which units being linked through an oxygen or a sulfur atom, through a group —SO 2 —, —NH—, —NH 2   +—, —N(C   1 - 16 alkyl)- or —COO—, or through an arylene or cycloalkylene radical and M is a metal. 
     
     
         2 . The aircraft tire tread of  claim 1 , wherein the polyisoprene rubber is a natural rubber. 
     
     
         3 . The aircraft tire tread of  claim 2 , wherein the aircraft tread comprises 100 phr of natural rubber. 
     
     
         4 . The aircraft tire tread of  claim 1 , wherein the highly unsaturated diene rubber is a polybutadiene rubber. 
     
     
         5 . The aircraft tire tread of  claim 1 , wherein the highly unsaturated diene rubber is selected from a polybutadiene rubber, a styrene-butadiene rubber or combinations thereof. 
     
     
         6 . The aircraft tire tread of  claim 1 , wherein the number-average molecular weight of the polyterpene resin is between 400 and 2000 g/mol. 
     
     
         7 . The aircraft tire tread of  claim 1 , wherein M is an alkali metal, magnesium, calcium, barium, zinc, cobalt or nickel. 
     
     
         8 . The aircraft tire tread of  claim 1 , wherein the poly-thiosulfate anti-reversion agent includes the water of crystallization. 
     
     
         9 . The aircraft tire of  claim 1 , wherein X is a radical of pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, dodecamethylene or hexadecamethylene and M is sodium, magnesium, calcium, barium, zinc, cobalt, or nickel. 
     
     
         10 . The aircraft tire of  claim 1 , wherein the poly-thiosulfate anti-reversion agent is hexamethylene 1,6-bis(thiosulfate), disodium salt, dihydrate. 
     
     
         11 . The aircraft tire of  claim 1 , wherein the poly-thiosulfate anti-reversion agent is in an amount of between 0.1 phr and 7 phr. 
     
     
         12 . The aircraft tire of  claim 1 , wherein the poly-thiosulfate anti-reversion agent is in an amount of between 1 phr and 6 phr. 
     
     
         13 . The aircraft tire of  claim 1 , wherein the poly -thiosulfate anti-reversion agent is in an amount of between 1 phr and 3 phr. 
     
     
         14 . An aircraft tire tread formed from a material that is based upon a cross-linkable rubber composition, the cross-linkable rubber composition comprising, per 100 parts by weight of rubber:
 natural rubber;   between 1 phr and 25 phr of a polyterpene resin having a glass transition temperature of between 50° C. and 120° C.; and   between 1 phr and 5 phr of a poly-thiosulfate anti-reversion agent having the formula:
   MO 3 S—S—X—S—SO 3 M
 
   
       wherein X is an alkylene radical or a radical comprising two or more alkylene units, pairs of which units being linked through an oxygen or a sulfur atom, through a group —SO 2 —, —NH—, —NH 2   + —, —N(C 1 - 16 alkyl)- or —COO—, or through an arylene or cycloalkylene radical and M is a metal. 
     
     
         15 . The aircraft tire tread of  claim 14 , wherein the poly-thiosulfate anti-reversion agent includes the water of crystallization. 
     
     
         16 . The aircraft tire of  claim 14 , wherein X is a radical of pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, dodecamethyene or hexadecamethylene and M is sodium, magnesium, calcium, barium, zinc, cobalt, or nickel. 
     
     
         17 . The aircraft tire of  claim 14 , wherein the poly-thiosulfate anti-reversion agent is hexamethylene 1,6-bis(thiosulfate), disodium salt, dihydrate. 
     
     
         18 . The aircraft tire tread of  claim 1 , wherein the number-average molecular weight of the polyterpene resin is between 400 and 2000 g/mol. 
     
     
         19 . The aircraft tire of tread 14, wherein the polyterpene resin is between 1 phr and 15 phr. 
     
     
         20 . A heavy vehicle tire tread formed from a material that is based upon a cross-linkable rubber composition, the cross-linkable rubber composition comprising, per 100 parts by weight of rubber:
 between 40 phr and 100 phr of a polyisoprene rubber;   between 0 and 60 phr of a highly unsaturated diene rubber;   between 1 phr and 25 phr of a polyterpene resin having a glass transition temperature of between 50° C. and 120° C.; and   between 0.1 phr and 10 phr of a poly-thiosulfate anti-reversion agent having the formula:
   MO 3 S—S—X—S—SO 3 M
 
   
       wherein X is an alkylene radical or a radical comprising two or more alkylene units, pairs of which units being linked through an oxygen or a sulfur atom, through a group —SO 2 —, —NH—, —NH 2   + —, —N(C 1 - 16 alkyl)- or —COO—, or through an arylene or cycloalkylene radical and M is a metal.