Rubber composition and pneumatic tire using the same

Abstract

A rubber composition capable of improving all of processability, abrasion resistance, rolling resistance property and wet skid performance and a pneumatic tire using the same are provided. A rubber composition comprising 25 to 100 parts by weight of a surface-treated silica based on 100 parts by weight of a rubber component comprising a natural rubber and/or a diene synthetic rubber, the surface-treated silica being obtainable by mixing a silica and a sulfur-containing organic silicon compound represented by the general formula (1): or the general formula (2): in an amount of 1 to 20 parts by weight of the sulfur-containing organic silicon compound on the basis of 100 parts by weight of the silica under a temperature of 130° to 180° C.

1 . A rubber composition comprising 25 to 100 parts by weight of a surface-treated silica based on 100 parts by weight of a rubber component comprising a natural rubber and/or a diene synthetic rubber, said surface-treated silica being obtainable by mixing a silica and a sulfur-containing organic silicon compound represented by the general formula (1): 
     
       
         
         
             
             
         
       
     
     wherein each of R 1  to R 3  is an alkyl group or alkoxy group having 1 to 12 carbon atoms, R 4  is an alkylene group having 1 to 6 carbon atoms, Z is R 1 R 2 R 3 —Si—R 4 — or an alkyl group, acyl group or aryl group which have 1 to 12 carbon atoms, and R 1  to R 4  and Z may be the same or different; x represents the number of sulfur atoms at the polysulfide portion and an average value of x is 2 to 5, 
     or the general formula (2): 
     
       
         
         
             
             
         
       
     
     wherein each of R 1  to R 3  is an alkyl group or alkoxy group having 1 to 12 carbon atoms, each of R 4  and R 5  is an alkyl group having 1 to 6 carbon atoms, and R 1  to R 5  may be the same or different, 
     in an amount of 1 to 20 parts by weight of said a sulfur-containing organic silicon compound on the basis of 100 parts by weight of said silica under a temperature of 130° to 180° C. 
   
   
       2 . The rubber composition of  claim 1 , wherein when said surface-treated silica is extracted by a solvent, an amount of an unreacted sulfur-containing organic silicon compound contained in an extracted solution is at most 50% by weight. 
   
   
       3 . The rubber composition of  claim 1 , wherein the surface-treated silica is prepared by reacting the sulfur-containing organic silicon compound with said silica in the presence of 0.1 to 10 parts by weight of an acidic compound on the basis of 100 parts by weight of said silica. 
   
   
       4 . The rubber composition of  claim 1 , wherein the surface-treated silica is prepared by reacting the sulfur-containing organic silicon compound with said silica in the presence of 0.1 to 10 parts by weight of a basic compound on the basis of 100 parts by weight of said silica. 
   
   
       5 . The rubber composition of  claim 1 , wherein the surface-treated silica is prepared by reacting a portion of the sulfur-containing organic silicon compound with said silica in the presence of 0.1 to 10 parts by weight of an acidic compound on the basis of 100 parts by weight of said silica, and then, by reacting the residual sulfur-containing organic silicon compound with said silica in the presence of 0.1 to 10 parts by weight of a basic compound on the basis of 100 parts by weight of said silica. 
   
   
       6 . The rubber composition of  claim 3 , wherein the acidic compound is a sodium salt and/or a potassium salt. 
   
   
       7 . The rubber composition of  claim 4 , wherein the basic compound is a sodium salt and/or a potassium salt. 
   
   
       8 . The rubber composition of  claim 5 , wherein the acidic compound and/or the basic compound is a sodium salt and/or a potassium salt. 
   
   
       9 . A pneumatic tire which comprises the rubber composition of  claim 1 . 
   
   
       10 . A pneumatic tire which comprises the rubber composition of  claim 3 . 
   
   
       11 . A pneumatic tire which comprises the rubber composition of  claim 4 .