RUBBER COMPOSITION FOR TIRE AND PNEUMATIC TIRE

• Main Authors: ASHIURA MAKOTO, UENISHI KAZUYA, SHINKE YU
• Format: Patent
• Language: English; Japanese
• Published: 20.09.2018
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; DEVICES OR ARRANGEMENTS RELATED TO TYRES; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; REPAIRING, OR CONNECTING VALVES TO, INFLATABLE ELASTIC BODIESIN GENERAL; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; TYRE CHANGING OR REPAIRING; TYRE INFLATION; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; VEHICLE TYRES; VEHICLES IN GENERAL

PROBLEM TO BE SOLVED: To provide a rubber composition for tire, which shows excellent processability, wet performance, low rolling resistance performance, wear resistance and toughness, and a pneumatic tire that uses the rubber composition for tire.SOLUTION: A rubber composition for tire comprises a diene-based rubber, silica and a silane coupling agent having a mercapto group, in which the diene-based rubber contains an aromatic vinyl-conjugate diene copolymer that is a copolymer of an aromatic vinyl and a conjugate diene in the range of 10 to 50 mass%, and has an average glass transition temperature of -50°C or higher, and the aromatic vinyl-conjugate diene copolymer has a content of repeating units derived of the aromatic vinyl of 18 mass% or larger, and has the glass transition temperature of -60°C or lower, and, among the repeating units derived from the conjugate diene compound, ratios of vinyl structures, 1,4-trans structures and 1,4-cis structures are in the specific ranges, a content of silica is 30 to 80 pts.mass relative to 100 pts.mass of the diene-based rubber, and a content of the silane coupling agent is 2.0 to 20 mass% relative to the content of silica.SELECTED DRAWING: Figure 1 【課題】加工性、ＷＥＴ性能、低転がり抵抗性、耐摩耗性及び靭性に優れるタイヤ用ゴム組成物並びに上記組成物を用いた空気入りタイヤを提供する。【解決手段】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、ジエン系ゴムが、芳香族ビニルと共役ジエンとの共重合体である芳香族ビニル−共役ジエン共重合体を１０〜５０質量％含み、平均ガラス転移温度が−５０℃以上であり、芳香族ビニル−共役ジエン共重合体が、芳香族ビニルに由来する繰り返し単位の含有量が１８質量％以上であり、ガラス転移温度が−６０℃以下であり、共役ジエンに由来する繰り返し単位のうち、ビニル構造、１，４−トランス構造及び１，４−シス構造の割合が特定の範囲であり、シリカの含有量がジエン系ゴム１００質量部に対して３０〜８０質量部であり、上記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２．０〜２０質量％である、タイヤ用ゴム組成物。【選択図】図１