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, comprises:
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 hydrate silicate is heated at 750° C. for 3 hours; and “weight loss on heating” (mass %) represents weight loss when the hydrate silicate 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”)≧2.5 (mass %)  (III)