申请人:SUMITOMO RUBBER INDUSTRIES, LTD.
公开号:EP2905305A1
公开(公告)日:2015-08-12
Provided is a pneumatic tire including a bead apex and/or sidewall reinforcing layer, which achieves balanced improvements in high-hardness properties, elongation at break, and self-heating properties to provide good run-flat durability while maintaining good processability. The pneumatic tire includes a bead apex and/or sidewall reinforcing layer formed from a rubber composition, the composition containing a rubber component (A) and carbon black (B), the rubber component (A) containing, per 100% by mass thereof: 10-75% by mass of a modified butadiene rubber (A1) with a cis content of 50% by mass or less; 5-40% by mass of a polybutadiene rubber (A2) containing 1,2-syndiotactic polybutadiene crystals; and 10-40% by mass of a diene rubber (A3) different from (A1) and (A2), the composition containing 35-65 parts by mass of carbon black (B) per 100 parts by mass of rubber component (A), the carbon black (B) having a BET specific surface area of 18-50 m2/g.
本发明提供了一种充气轮胎,包括胎圈顶点和/或胎侧补强层,该轮胎在高硬度性能、断裂伸长率和自热性能方面实现了平衡改进,从而在保持良好加工性能的同时提供良好的跑胎耐久性。该充气轮胎包括由橡胶组合物形成的胎圈顶点和/或胎侧增强层,该组合物含有橡胶成分(A)和炭黑(B),橡胶成分(A)按其质量百分比计算含有10-75%(质量)的改性丁二烯橡胶(A1),其顺式含量为 50%(质量)或更低;5-40%(质量)的聚丁二烯橡胶(A2),其含有 1,2-双向聚丁二烯晶体;以及 10-40%(质量)的二烯橡胶(A3),其不同于(A1)和(A2),该组合物含有 35-65 份(质量)的炭黑(B)(每 100 份(质量)橡胶成分(A)),炭黑(B)的 BET 比表面积为 18-50 m2/g。