Bridgestone Corporation

Nobumitsu Ohshima

Setsuo Akiyama

Ryuji Izumoto

Jingo Shirasaka

A rubber composition having a high hysteresis loss is provided without impairment of other physical properties, such as fracture characteristics. The rubber composition includes 100 parts by weight of a rubber component, 0.1 to 100 parts by weight of graphitized carbon material, and a lipid the amount of which is 0.02 to 0.2 times the amount of the graphitized carbon material. Preferably, the graphitized carbon material is carbon fiber grown from a vapor phase or graphitized carbon black, and the lipid is a fatty acid. Preferably, the rubber composition according to the present invention has a loss tangent tan &#x3b4; in the range of 0.05 to 0.5 at a temperature of 60 degree C. after vulcanization.

Rubber composition

Reclaimed rubber which is obtained through devulcanization and has excellent physical properties as a vulcanized material, and a process for producing the same are provided. In the reclaimed rubber obtained by devulcanizing vulcanized rubber, the proportion of sol is 80% or higher, and the peak top molecular weight of sol as determined by gel permeation chromatography (GPC) is 100,000 or less.

Reclaimed rubber and process for producing the same

Reclaimed rubber having excellent performance is applied for reuse in tires or for asphalt, etc. The reclaimed rubber obtained by devulcanization treatment of vulcanized rubber from discard tires, etc. has a proportion of sol to gel: 10-80%, a weight-average molecular weight (Mw) of the sol by gel permeation chromatography (GPC): 20,000-300,000, and a degree of swelling of the gel: 3.0-20.0. A process for reclaiming the vulcanized rubber is also disclosed.

Growing community of inventors

Tokyo, Japan

Nobumitsu Ohshima