Processes for forming vulcanizable elastomeric formulations and vulcanized elastomeric articles

Abstract

Processes for forming a vulcanizable elastomeric formulation are disclosed. The processes include the steps of mixing an elastomer with a vulcanizing agent to form a vulcanizable elastomeric formulation that includes the vulcanizing agent dispersed in the elastomeric compound, wherein the vulcanizing agent includes a cyclododecasulfur compound. A process for forming a vulcanized elastomeric article is also described.

1 . A process for forming a vulcanized elastomeric article, said process comprising (a) mixing an elastomer with a vulcanizing agent to form a vulcanizable elastomeric formulation that includes said vulcanizing agent dispersed in said elastomer; (b) forming the vulcanizable elastomeric formulation into a formed shape; and (c) vulcanizing the formed shape to form said vulcanized elastomeric article; wherein at least one of said mixing and forming steps comprises increasing the bulk average processing temperature of said vulcanizable elastomeric formulation to greater than 125° C. for at least a portion of said step. 
     
     
         2 . The process of  claim 1 , wherein at least one of said mixing and forming steps comprises increasing the bulk average processing temperature of said vulcanizable elastomeric formulation to greater than 128° C. for at least a portion of said step. 
     
     
         3 . The process of  claim 1 , wherein at least one of said mixing and forming steps comprises increasing the bulk average processing temperature of said vulcanizable elastomeric formulation to greater than 130° C. for at least a portion of said step. 
     
     
         4 . The process of  claim 14 , wherein at least one of said mixing and forming steps comprises increasing the bulk average processing temperature of said vulcanizable elastomeric formulation to greater than 135° C. for at least a portion of said step. 
     
     
         5 . The process of  claim 1 , wherein the vulcanizing agent comprises a cyclododecasulfur compound characterized by a DSC melt point onset of from about 155° C. to about 167° C. when measured at a DSC heat rate of 20° C./minute. 
     
     
         6 . The process of  claim 5 , wherein said cyclododecasulfur compound is characterized by a DSC melt point onset of between 157° C. to about 167° C. when measured at a DSC heat rate of 20° C./minute. 
     
     
         7 . The process of  claim 1 , wherein the vulcanizing agent comprises a cyclododecasulfur compound. 
     
     
         8 . The process of  claim 1 , wherein said vulcanizable elastomeric formulation further comprises at least one of an antireversion agent, a prevulcanization inhibitor and retarder. 
     
     
         9 . The process of  claim 1 , wherein said vulcanizing composition further comprises an antireversion agent. 
     
     
         10 . The process of  claim 9 , wherein said antireversion agent is selected from the group consisting of hexamethylene-1,6-bis(thiosulfate), disodium salt, dihydrate and 1,3-bis(citraconamidomethyl)benzene. 
     
     
         11 . The process of  claim 8 , wherein said vulcanizable elastomeric formulation composition further comprises a prevulcanization inhibitor. 
     
     
         12 . The process of  claim 11 , wherein said prevulcanization inhibitor is N-(cyclohexylthio) phthalimide. 
     
     
         13 . The process of  claim 1 , wherein said vulcanizable elastomeric formulation further comprises at least one crosslinker selected from the group consisting of polysulfides, polysulfide mixtures and crosslinked organosilicon polysulfides. 
     
     
         14 . The process of  claim 1 , wherein said vulcanizable elastomeric formulation further comprises at least one accelerator selected from the group consisting of 2-mercaptobenzothiazole, 2-mercaptobenzothiazole disulfide and asymmetric disulfides based on 2-mercaptobenzothiazole and a non-accelerating mercapto containing moiety.