Method of improving carbon black dispersion in rubber compositions

Abstract

A method for forming a vulcanizable composition of matter, the method comprising providing a polymer cement or latex comprising at least one rubber, adding at least one processing aid to the cement or latex to form a modified rubber cement or latex, isolating the rubber and at least one processing aid to form a premix, and mixing the premix with carbon black.

What is claimed is:  
     
         1 . A method for forming a vulcanizable composition of matter, the method comprising: 
 providing a polymer cement or latex comprising at least one rubber;    adding at least one processing aid to the cement or latex to form a modified rubber cement or latex;    isolating the rubber and at least one processing aid to form a premix; and    mixing the premix with carbon black.    
     
     
         2 . The method of  claim 1 , where said step of adding at least one processing aid to the cement or latex includes forming a cocktail, which includes the processing aid and a solvent, and adding the cocktail to the cement or latex.  
     
     
         3 . The method of  claim 2 , where said step of forming the cocktail includes heating the processing aid and solvent to a temperature of from about 30 to about 140° C.  
     
     
         4 . The method of  claim 3 , where said step of forming the cocktail includes combining the processing aid and solvent with an oil.  
     
     
         5 . The method of  claim 4 , where the cocktail includes from about 10 to about 50 parts by weight processing aid, from about 100 to about 35 parts by weight solvent, and from about 0 to about 65 parts by weight oil.  
     
     
         6 . The method of  claim 1 , where said step of adding at least one processing aid to the cement or latex includes forming a cocktail, which includes the processing aid and an oil, and adding the cocktail to the cement or latex.  
     
     
         7 . The method of  claim 1 , where said step of isolating includes drying the rubber and processing agent.  
     
     
         8 . The method of  claim 1 , where said step of mixing occurs within a mixer having a net mixing chamber volume of at least about 75 L operated at a fill factor of at least about 50.  
     
     
         9 . The method of  claim 1 , where the at least one processing aid is a polar organic compound, a resin, a low molecular weight polymer, or a mixture thereof.  
     
     
         10 . The method of  claim 9 , where the polar organic compound is a high-HLB surfactant, an ester, a ketone, an aldehyde, an ether, an amide, an amine, a carboxylic acid, a fatty acid, a sulfonic acid, an organic sulfate, a metal carboxylate, a metal sulfonate, or a mixture thereof.  
     
     
         11 . The method of  claim 10 , where the fatty acid salt includes a mixture of zinc fatty acid salts.  
     
     
         12 . The method of  claim 1 , where the rubber is a functionalized rubber.  
     
     
         13 . The method of  claim 12 , where the functionalized rubber is prepared by anionically polymerizing conjugated dienes, alone or in combination with vinyl aromatic monomers, and where the polymerization is initiated with a cyclic amine initiator or a tin-lithio initiator.  
     
     
         14 . The method of  claim 12 , where the functionalized rubber is prepared by terminating a polymerization with a coupling or functional terminating agent.  
     
     
         15 . The method of  claim 12 , where the functionalized rubber includes both head and tail functionalization.  
     
     
         16 . The method of  claim 1 , further comprising the step of shaping the vulcanizable composition of matter into a green tire component, and further comprising the step of curing the tire component.  
     
     
         17 . The method of  claim 1 , where said step of adding at least one processing aid includes adding from about 0.1 to about 15 parts by weight processing aid per 100 parts by weight rubber.  
     
     
         18 . The method of  claim 1 , where said step of adding at least one processing aid includes adding from about 0.5 to about 12 parts by weight processing aid per 100 parts by weight rubber.  
     
     
         19 . A tire tread prepared by a method comprising: 
 preparing a vulcanizable composition of matter by providing a rubber cement or latex comprising at least one rubber, adding at least one processing aid to the rubber cement or latex to form a modified rubber cement or latex, isolating the rubber and at least one processing aid to form a premix, mixing the premix with carbon black;    shaping the vulcanizable composition of matter into a green tire tread, and    curing the tire tread.    
     
     
         20 . A method for increasing the dispersion of carbon black within a carbon-black filled tire component, the method comprising: 
 providing a rubber cement or latex comprising at least one rubber;    adding at least one processing aid to the rubber cement or latex to form a modified rubber cement or latex;    isolating the rubber and at least one processing aid from the solvent to form a premix; and    mixing the premix with carbon black.