JPS649248A - Rubber composition for tire - Google Patents

Abstract

PURPOSE:To obtain the title composition excelling in heat build-up resistance and reinforcing property and heat aging resistance at high temperature, by mixing a rubber component with a specified reinforcing carbon black, silica, a triazine compound and a silane coupling agent. CONSTITUTION:Carbon black is surface-treated by vacuum low-temperature plasma treatment to obtain reinforcing carbon black (B) of a nitrogen adsorption specific surface area of 70-200m<2>/g, a compressed dibutyl phthalate absorption of 80-130ml/100g, a concentration of phenolic hydroxyl groups introduced to the surface of 3.0X10<12>-8.1X10<14> piece/m<2> and a pH value of 3-5. 100pts.wt. rubber component (A) selected from among natural and diene synthetic rubbers is mixed with 30-200pts.wt. component B, 2-30pts.wt. silica (C), 0.1-2pts.wt. triazine compound (D) of formula I [wherein Ra is -NR'2 (wherein R' is a 2-4C alkyl), -NHR'' (wherein R'' is R' or phenyl), Rb is -SH, formula II or -N(C2H5)2, Rc is -H or formula III or IV] and 4.65X10<-3>-4.65X10<-3>m, S pts.wt. (wherein m is the number of pts.wt. of component B added and S is the nitrogen adsorption specific surface area of component B), silane coupling agent (E) of formula V, VI or VII (wherein X is cyano, mercapto or the like, Y is a 1-4C alkyl, Cl or the like,m is 1-6, and X is formula III, IX or X).