Methods for manufacturing a tread for agricultural tire using a dinitrile oxide cure system

Abstract

A method of manufacturing a tread for agricultural tires, the method comprising providing an agricultural tire casing, providing a cured rubber component having first and second planar surfaces, providing a plurality of cushion gums, wherein the plurality of cushion gums contains a cure system comprising a stable dinitrile oxide compound, providing a plurality of lugs, and forming an agricultural tread composite by mating the lugs to a planar surface of the cured rubber component using the cushion gum.

What is claimed is: 
     
         1 . A method of retreading a used agricultural tire, the method comprising:
 (i) providing a used agricultural tire casing from the used agricultural tire;   (ii) providing a cured rubber component having first and second planar surfaces;   (iii) providing a plurality of lug cushion gums, wherein each lug cushion gum of the plurality of lug cushion gums contains a cure system comprising a stable dinitrile oxide compound;   (iv) providing a plurality of lugs; and   (v) mating the plurality of lug cushion gums to the plurality of lugs to form a plurality of mated lugs,   (vi) mating the plurality of mated lugs to the cured rubber component to form a mated cured rubber component, and   (vii) mating the mated cured rubber component to the used agricultural tire casing to form a pre-cured retread agricultural tire.   
     
     
         2 . The method of  claim 1 , further comprising the step of treating the pre-cured retread agricultural tire to form a retread agricultural tire. 
     
     
         3 . The method of  claim 1 , wherein the lugs contain at least about 50 wt. % synthetic polyisoprene or natural rubber. 
     
     
         4 . The method of  claim 1 , wherein the first planar surface of the cured rubber component includes a plurality of recesses and said step of mating the plurality of mated lugs includes aligning the plurality of mated lugs with the plurality of recesses. 
     
     
         5 . The method of  claim 4 , wherein said step of mating includes placing the plurality of mated lugs on the first planar surface of the cured rubber component. 
     
     
         6 . The method of  claim 1 , wherein the cured rubber component contains at least about 50 wt. % synthetic polyisoprene or natural rubber. 
     
     
         7 . The method of  claim 1 , wherein the at least one stable dinitrile oxide compound is a stable aryl dinitrile oxide. 
     
     
         8 . The method of  claim 7 , wherein the stable aryl dinitrile oxide is selected from the group consisting of mesitylene dinitrile oxide (MDNO) and bismesitylene dinitrile oxide (BMNO). 
     
     
         9 . The method of  claim 1 , wherein the step of providing a plurality of lug cushion gums further comprises extruding a lug cushion gum composition to form each lug cushion gum of the plurality of lug cushion gums. 
     
     
         10 . The method of  claim 1 , wherein the plurality of lug cushion gums each contain at least about 50 wt. % synthetic polyisoprene or natural rubber. 
     
     
         11 . The method of  claim 2 , where said step of treating includes encasing the pre-cured retread agricultural tire in an envelope; placing the enveloped pre-cured retread agricultural tire in a pressure chamber at a temperature between about 10° C. and about 60° C.; and applying pressure to the enveloped pre-cured retread agricultural tire to form the retread agricultural tire. 
     
     
         12 . The method of  claim 1 , further comprising:
 (i) providing a casing cushion gum for mating the cured rubber component to the tire casing, wherein the casing cushion gum contains a cure system comprising a stable dinitrile oxide compound;   (ii) applying the casing cushion gum to the agricultural tire casing; and   (iii) applying the second planar surface of the cured rubber component to the second cushion gum.   
     
     
         13 . The method of  claim 12 , wherein said step of mating the mated lugs to the cured rubber component and said step of mating the mated cured rubber component takes place at a location, and wherein said steps of providing the plurality of lug cushion gums and providing the casing cushion gum take place at the same location. 
     
     
         14 . The method of  claim 1 , wherein said step of providing an agricultural tire casing comprises preparing an agricultural tire casing to have a buffed surface by buffing off a tread portion and lugs of an agricultural tire. 
     
     
         15 . The method of  claim 1 , wherein said step of providing the used agricultural tire casing comprises preparing the used agricultural tire casing to have a buffed surface by buffing off a tread portion, lugs, and a subtread of the used agricultural tire. 
     
     
         16 . A method of manufacturing an agricultural tire, the method comprising:
 (i) providing a newly manufactured agricultural tire casing;   (ii) providing a plurality of lug cushion gums, wherein said plurality of lug cushion gums each contain a cure system comprising a stable dinitrile oxide compound;   (iii) providing a plurality of lugs;   (iv) mating the plurality of lug cushion gums to the plurality of lugs to form a plurality of mated lugs; and   (v) mating the plurality of mated lugs to newly manufactured agricultural tire casing to form a pre-cured retread agricultural tire.   
     
     
         17 . The method of  claim 16 , wherein the lugs contain at least about 50 wt. % synthetic polyisoprene or natural rubber, wherein the newly manufactured agricultural tire casing contains at least about 50 wt. % synthetic polyisoprene or natural rubber, and wherein the plurality of lug cushion gums each contain at least about 50 wt. % synthetic polyisoprene or natural rubber. 
     
     
         18 . The method of  claim 16 , wherein the at least one stable dinitrile oxide compound is a stable aryl dinitrile oxide, and wherein the stable aryl dinitrile oxide is selected from the group consisting of mesitylene dinitrile oxide (MDNO) and bismesitylene dinitrile oxide (BMNO). 
     
     
         19 . The method of  claim 16 , wherein the step of providing a plurality of lug cushion gums further comprises extruding a lug cushion gum composition to form each lug cushion gum of the plurality of lug cushion gums. 
     
     
         20 . The method of  claim 16 , further comprising a step of treating the pre-cured retread agricultural tire, where said step of treating includes encasing the pre-cured retread agricultural tire in an envelope; placing the enveloped pre-cured retread agricultural tire in a pressure chamber at a temperature between about 10° C. and about 60° C.; and applying pressure to the enveloped pre-cured retread agricultural tire to form a retread agricultural tire.