RUBBER COMPOSITION FOR STUDLESS TIRES, AND STUDLESS TIRE

• Main Authors: ASHIURA MAKOTO, MIHARA SATOSHI, KAGEYAMA YUICHI, KAZARIYA AYAKI, KIMURA KAZUTOSHI
• Format: Patent
• Language: English; Japanese
• Published: 04.04.2019
• 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

To provide a rubber composition for studless tires which is excellent in processability and is excellent in on-ice performance when formed into a studless tire, and to provide a studless tire using the rubber composition for studless tires.SOLUTION: The rubber composition for studless tires contains: a diene rubber; silica; a heterocyclic compound having a C3-30 hydrocarbon group and at least one heterocyclic ring selected from the group consisting of a piperazine ring, a morpholine ring, and a thiomorpholine ring (provided that the heterocyclic compound has no silicon atom); and a sulfur-containing silane coupling agent. The diene rubber has an average glass transition temperature lower than -60°C. The content of the silica is 30-150 pts.mass based on 100 pts.mass of the diene rubber. The content of the heterocyclic compound is 0.5-20 mass% based on the silica. The content of the sulfur-containing silane coupling agent is 1-25 mass% based on the silica. The rubber composition for studless tires has a type A rubber hardness specified by JIS at a temperature of 0°C of 55 or less after curing.SELECTED DRAWING: Figure 1 【課題】加工性に優れ、スタッドレスタイヤにしたときの氷上性能に優れるスタッドレスタイヤ用ゴム組成物、ならびに、スタッドレスタイヤ用ゴム組成物を用いたスタッドレスタイヤ用の提供。【解決手段】ジエン系ゴムと、シリカと、炭素数３〜３０とピペラジン環、モルホリン環及びチオモルホリン環からなる群から選ばれる少なくとも１種のヘテロ環とを有するヘテロ環化合物（ただしヘテロ環化合物はケイ素原子を有さない。）と、硫黄含有シランカップリング剤とを含有し、ジエン系ゴムの平均ガラス転移温度が−６０℃未満であり、シリカの含有量がジエン系ゴム１００質量部に対して３０〜１５０質量部であり、ヘテロ環化合物の含有量がシリカに対して０．５〜２０質量％であり、硫黄含有シランカップリング剤の含有量がシリカに対して１〜２５質量％であり、硬化後の、温度０℃におけるＪＩＳ規定のタイプＡのゴム硬度が５５以下である、スタッドレスタイヤ用ゴム組成物。【選択図】図１