Rubber composition for tire, vulcanized rubber composition for tire, and tires using same

摘要

An object of the present invention is to provide a rubber composition for a tire, capable of achieving both good rolling resistance properties and good wear resistance in a sufficiently compatible manner when the rubber composition is applied to a component member of a tire. Specifically, the present invention provides a rubber composition comprising a rubber composition and hydrated silica, wherein “CTAB” (m2/g) as specific surface area by cetyltrimethylammonium bromide adsorption and “IB” as ink bottle-shaped micropore index, of the hydrated silica, satisfy a specific relationship and “weight loss on ignition” as weight loss when the hydrate silicate is heated at 750° C. for 3 hours and “weight loss on heating” as weight loss when the hydrate silicate is heated at 105° C. for 2 hours satisfy a specific relationship.

主权项

1. A rubber composition for a tire comprising:
a rubber component; and a hydrated silica having particles each provided with micropores with openings in the range of 1.2×105 nm to 6 nm formed at outer surface of the particle, wherein the rubber component contains a modified polymer reactive to the hydrated silica, and in measurement according to a mercury press-in method using a mercury porosimeter of the hydrated silica, provided that: M1 (nm) represents diameter of the opening exhibiting the maximum value of mercury charge rate when pressure is increased from 1 PSI to 32000 PSI; M2 (nm) represents diameter of the opening exhibiting the maximum value of mercury discharge rate when pressure is decreased from 32000 PSI to 1 PSI; IB represents ink bottle-shaped micropore index;
IB=M2−M1  (X); CTAB (m2/g) represents specific surface area by cetyltrimethylammonium bromide adsorption; weight loss on ignition (mass %) represents weight loss when the hydrated silica is heated at 750° C. for 3 hours; and weight loss on heating (mass %) represents weight loss when the hydrated silica is heated at 105° C. for 2 hours, IB and CTAB satisfy following formula (I) and formula (II) and weight loss on ignition and weight loss on heating satisfy formula (III),
IB≦−0.56×CTAB+110.4 (when CTAB≦140)  (I)IB≦−0.20×CTAB+60.0 (when CTAB>140)  (II)(weight loss on ignition−weight loss on heating)≧3.2 (mass %)  (III-1′).