RUBBER COMPOSITION FOR TIRE TREAD, AND PNEUMATIC TIRE

• Main Authors: ASHIURA MAKOTO, SAWA HIDEAKI, KAZARIYA AYAKI, SATO MASAKI
• Format: Patent
• Language: English; Japanese
• Published: 21.11.2019
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; DEVICES OR ARRANGEMENTS RELATED TO TYRES; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; REPAIRING, OR CONNECTING VALVES TO, INFLATABLE ELASTIC BODIESIN GENERAL; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS; TYRE CHANGING OR REPAIRING; TYRE INFLATION; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; VEHICLE TYRES; VEHICLES IN GENERAL

To provide a rubber composition for a tire tread which is excellent in wet performance and rolling performance when formed into a tire and is excellent in suppression of a change in viscosity with time, and to provide a pneumatic tire using the rubber composition for a tire tread.SOLUTION: The rubber composition for a tire tread contains: a conjugated diene rubber containing 30 mass% or more of a specific conjugated diene rubber produced by a method for producing a conjugated diene rubber comprising specific steps; silica; and a silane coupling agent having a mercapto group. The content of the silica is 30 pts.mass or more based on 100 pts.mass of the conjugated diene rubber. The content of the silane coupling agent is 3-40 mass% based on the content of the silica.SELECTED DRAWING: Figure 1 【課題】タイヤにしたときのウェット性能、タイヤにしたときの転がり性能及び粘度の経時変化の抑制に優れるタイヤトレッド用ゴム組成物、並びに、上記タイヤトレッド用ゴム組成物を用いた空気入りタイヤの提供。【解決手段】特定の工程を備える共役ジエン系ゴムの製造方法により製造される特定共役ジエン系ゴムを３０質量％以上含む共役ジエン系ゴムと、シリカと、メルカプト基を有するシランカップリング剤とを含有し、シリカの含有量が共役ジエン系ゴム１００質量部に対して３０質量部以上であり、シランカップリング剤の含有量がシリカの含有量に対して３〜４０質量％である、タイヤトレッド用ゴム組成物。【選択図】図１