Severely Hydrotreated Naphthenic Distillate Containing Rubber Compositions

Abstract

A composition includes at least one natural or synthetic rubber material, a severely hydrotreated naphthenic distillate incorporated in amount equal to or less than 30% by weight of the composition, and a sulfur curative. After curing, the composition provides acceptable cold flexibility at a temperature lower than −60 deg C., at a temperature as low as −68 deg C., or even at a temperature as low as −73 deg C. In some aspects, the at least one natural or synthetic rubber material is a synthetic rubber such as, but not limited to, an ethylenepropylene-diene copolymer rubber. In some cases, where used, the ethylenepropylene-diene copolymer rubber is selected from the group consisting of ethylene-propylene-cyclopentadiene terpolymer, ethylene-propylene ethylidene norbornene terpolymer, ethylene-propylene-I, and mixtures thereof.

What is claimed is: 
     
         1 . A composition comprising:
 a) at least one natural or synthetic rubber material;   b) a severely hydrotreated naphthenic distillate incorporated in amount equal to or less than 30% by weight of the composition; and,   c) a sulfur curative;   
       wherein after curing, the composition provides acceptable cold flexibility at a temperature lower than −60 deg C. 
     
     
         2 . The composition of  claim 1 , wherein after curing, the composition provides acceptable cold flexibility at a temperature as low as −68 deg C. 
     
     
         3 . The composition of  claim 1 , wherein after curing, the composition provides acceptable cold flexibility at a temperature as low as −73 deg C. 
     
     
         4 . The composition of  claim 1 , wherein the at least one natural or synthetic rubber material is a synthetic rubber. 
     
     
         5 . The composition of  claim 4 , wherein the synthetic rubber is an ethylenepropylene-diene copolymer rubber. 
     
     
         6 . The composition of  claim 5 , wherein the ethylenepropylene-diene copolymer rubber is selected from the group consisting of ethylene-propylene-cyclopentadiene terpolymer, ethylene-propylene ethylidene norbornene terpolymer, ethylene-propylene-I, and mixtures thereof. 
     
     
         7 . The composition of  claim 1 , wherein the at least one natural or synthetic rubber material is incorporated in an amount from 22% by weight to 28% by weight based upon total composition weight. 
     
     
         8 . The composition of  claim 1  further comprising a curing accelerator. 
     
     
         9 . The composition of  claim 8 , wherein the curing accelerator is mercaptobenzothiazole. 
     
     
         10 . The composition of  claim 1  as incorporated into a layer of an air brake hose. 
     
     
         11 . A composition for forming a layer of a hose, the comprising:
 a) at least one natural or synthetic rubber material;   b) a severely hydrotreated naphthenic distillate incorporated in amount equal to or less than 30% by weight of the composition; and,   c) a sulfur curative.   
     
     
         12 . The composition of  claim 11 , wherein after curing, the composition provides acceptable cold flexibility at a temperature as low as −60 deg C. 
     
     
         13 . The composition of  claim 11 , wherein after curing, the composition provides acceptable cold flexibility at a temperature as low as −73 deg C. 
     
     
         14 . The composition of  claim 11 , wherein the at least one natural or synthetic rubber material is an ethylenepropylene-diene copolymer rubber. 
     
     
         15 . The composition of  claim 14 , wherein the ethylenepropylene-diene copolymer rubber is selected from the group consisting of ethylene-propylene-cyclopentadiene terpolymer, ethylene-propylene ethylidene norbornene terpolymer, ethylene-propylene-I, and mixtures thereof. 
     
     
         16 . The composition of  claim 11 , wherein the at least one natural or synthetic rubber material is incorporated in an amount from 22% by weight to 28% by weight based upon total composition weight. 
     
     
         17 . The composition of  claim 11  further comprising a curing accelerator. 
     
     
         18 . The composition of  claim 17 , wherein the curing accelerator is mercaptobenzothiazole. 
     
     
         19 . The composition of  claim 18  as incorporated into a layer of an air brake hose. 
     
     
         20 . A composition comprising:
 a) ethylenepropylene-diene copolymer rubber selected from the group consisting of ethylene-propylene-cyclopentadiene terpolymer, ethylene-propylene ethylidene norbornene terpolymer, ethylene-propylene-I, and mixtures thereof;   b) a severely hydrotreated naphthenic distillate incorporated in amount equal to or less than 30% by weight of the composition;   c) a sulfur curative; and,   d) a mercaptobenzothiazole curing accelerator;   
       wherein after curing, the composition provides acceptable cold flexibility at a temperature as low as −68 deg C.