Process for producing modified polymer, modified polymer obtained by the process, and rubber composition

Abstract

Provided is a process for producing a modified polymer, characterized by carrying out primary modification in which a hydrocarbyloxysilane compound is reacted with the active site of a polymer having an active site of an organic metal type in a molecule and then carrying out secondary modification in which the hydrocarbyloxysilane compound is further reacted therewith. This makes it possible to provide a modified polymer which enhances interactions with silica and carbon black when used for both of silica-blended and carbon black-blended rubber compositions and which elevates the fracture characteristic, the abrasion resistance and the low heat buildup property at the same time and can exhibit a good workability.

1 . A modified polymer obtained by a production process characterized by carrying out primary modification in which a hydrocarbyloxysilane compound I is reacted with the active site of a polymer having an active site of an organic metal in a molecule and then carrying out secondary modification in which a hydrocarbyloxysilane compound II or unreacted hydrocarbyloxysilane compound I is further reacted therewith.  
   
   
       2 . The modified polymer as described in  claim 1 , wherein the Mooney viscosity (ML 1+4 /100° C.) is 10 to 150.  
   
   
       3 . A rubber composition comprising the modified polymer as described in  claim 1 .  
   
   
       4 . The rubber composition as described in  claim 3  comprising 100 parts by weight of (A) a rubber component containing at least 30% by weight of the modified polymer and 10 to 100 parts by weight of (B) silica and/or carbon black.  
   
   
       5 . A pneumatic tire characterized by using the rubber composition as described in  claim 3.