A rubber composition useful as a tire side wall or tire tread is formed from an unsaturated olefin copolymer (A) or (A') and diene rubber (B). Copolymers (A) and (A') are each obtained from (i) ethylene, (ii) aromatic vinyl compound, (iii) non-conjugated polyene, and, optionally (iv) alpha-olefin having at least 3 carbon atoms. When used in forming a tire side wall, copolymer (A) has a molar ratio of (i)/(iv) from 100/0 to 40/60; molar ratio of [((i)+(iv))/(ii)] from 98/2 to 60/40; an intrinsic viscosity, measured in decalin, at 135.degree. C., from 1.0 to 6.0 dl/g; and iodine value from 10 to 50. For use in tire tread, copolymer (A'), has a molar ratio (i)/(iv) from 100/0 to 40/60; molar ratio [((i)+(iv)):(ii)] from 99/1 to 85/15. The weight ratio (A')/(B) is from 1/99 to 50/50. The compositions for tire side wall are characterized by excellent strength properties and bending fatigue resistance and low fuel consumption. The compositions for tire tread are characterized by superior strength properties, abrasion resistance and braking performance on wet road (wet ski resistance) and small rolling resistance.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a .sctn.371 entry into the United States based on International Application PCT/JP98/00216, filed Jan. 21, 1998.
Priority Data
Jan 21, 1997 [JP] 9-008887 Jan 28, 1997 [JP] 9-013736 Dec 08, 1997 [JP] 9-337508 Dec 08, 1997 [JP] 9-356255
Sulfur vulcanizable rubber composition which does not contain aromatic process oils including at least one diene elastomer, at least finely dispersed, precipitated silica and carbon as fillers, softeners, at least one silane coupling agent, and additional common additives as well as a process for their production. Additionally, the invention relates to rubber products and tires made based on such rubber compositions. The rubber composition can comprise 5 to 60 phr of at least one mineral oil softener as a softener, with a content of polycyclic aromatic compositions of less than 3 wt-% in relation to the total weight of the mineral oil softener, determined by the DMSO extract according to the IP 346 method, and a glass transition temperature below -45.degree. C., and 1 to 20 phr of at least one glyceride and/or of a factice, and the weight ratio of finely dispersed, precipitated silica to carbon black being 1:2 to 20:1 in the rubber composition.
