PROBLEM TO BE SOLVED: To provide a rubber composition that can improve wet grip performance, abrasion resistance and tensile performances in a well balanced manner, and a pneumatic tire having a tread manufactured by using the rubber composition.SOLUTION: The rubber composition includes: a rubber component comprising an oil-extended butadiene rubber having a cis content of 95 mol% or more, a vinyl content of 1.2 mol% or less, and a weight average molecular weight of 530000 or more, and/or a styrene-butadiene rubber having a bonded styrene amount of 10 to 60 mass% and a weight average molecular weight of 800000 or more; an inorganic reinforcement agent represented by formula:mM-xSiO-zHO, which has a nitrogen adsorption specific surface area of 10 to 60 m/g; and silica having a nitrogen adsorption specific surface area of 100 m/g or more and/or carbon black having a nitrogen adsorption specific surface area of 100 m/g or more. The oil-extended butadiene rubber is a butadiene rubber synthesized by using a rare earth catalyst; and the total content of the oil-extended butadiene rubber and the styrene butadiene rubber in the rubber component is 10 to 100 mass%. With respect to 100 parts by mass of the rubber component, the inorganic reinforcement agent is included by 1 to 70 parts by mass, and the silica and the carbon black in total are included by 50 parts by mass or more. In the formula of the inorganic reinforcement agent, M represents at least one metal selected from the group consisting of Al, Mg, Ti, Ca and Zr or an oxide or hydroxide of the metal; m represents an integer of 1 to 5; x represents an integer of 0 to 10; y represents an integer of 2 to 5; and z represents an integer of 0 to 10.
【課題】ウェットグリップ性能、耐摩耗性及び引張性能をバランス良く改善することができるゴム組成物、及び該ゴム組成物を用いて作製したトレッドを有する空気入りタイヤを提供する。【解決手段】シス含量95モル%以上、ビニル含量1.2モル%以下、重量平均分子量53万以上の油展ブタジエンゴム、及び/又は結合スチレン量10〜60質量%、重量平均分子量80万以上のスチレンブタジエンゴムを含むゴム成分と、下記式で表され、かつ窒素吸着比表面積10〜60m2/gの無機補強剤と、窒素吸着比表面積100m2/g以上のシリカ及び/又は窒素吸着比表面積100m2/g以上のカーボンブラックとを含み、前記油展ブタジエンゴムは、希土類元素系触媒を用いて合成されたブタジエンゴムであり、前記ゴム成分中における前記油展ブタジエンゴム及び前記スチレンブタジエンゴムの合計含有量が10〜100質量%であり、前記ゴム成分100質量部に対して、前記無機補強剤の含有量が1〜70質量部、前記シリカ及びカーボンブラックの合計含有量が50質量部以上であるゴム組成物。mM・xSiOy・zH2O(式中、MはAl、Mg、Ti、Ca及びZrからなる群より選ばれた少なくとも1種の金属、該金属の酸化物又は水酸化物であり、mは1〜5の整数、xは0〜10の整数、yは2〜5の整数、zは0〜10の整数である。)【選択図】なし
RUBBER COMPOSITION AND PNEUMATIC TIRE
ゴム組成物及び空気入りタイヤ
2015-12-24
Patent
Electronic Resource
Japanese
IPC: | C08L COMPOSITIONS OF MACROMOLECULAR COMPOUNDS , Massen auf Basis makromolekularer Verbindungen / B60C VEHICLE TYRES , Fahrzeugreifen / C08J Verarbeitung , WORKING-UP / C08K Verwendung von anorganischen oder nichtmakromolekularen organischen Stoffen als Zusatzstoffe , USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES AS COMPOUNDING INGREDIENTS |