| 摘要 |
PURPOSE:To make improvements in mechanical strength, heat resistance, ozoneproofness, external damage resistance, etc., by forming a tire side part of a pneumatic tire with a rubber composition containing organic rubber and specific polyorganosiloxane. CONSTITUTION:The whole layer (or at least an outer layer in both inner and outer layers), of a tire side part S ranging from an upper part of a bead part 2 in a radial-ply tire for passenger cars to a lower part of a shoulder part 4 via a sidewall part 3, is made up of a rubber composition containing organic rubber A and polyorganosiloxane B and its conpostite ratio is A/B=80/25-5/95. This polyorganosiloxane contains a double bonding hydrocarbon radical, not contains polyorganosiloxane 5-100wt% and a hydrocarbon or more than 20 in a degree of polymerization, and is formed from polyorganosiloxane 95-0wt% containing another bridging radical of more than 20 in the polymerization degree. |
