| abstract |
An ethylene-propylene-diene rubber which is excellent in co-vulcanizability with a conjugated diene rubber and which can impart excellent weather resistance, ozone resistance and heat aging resistance without adversely affecting the excellent mechanical properties, wear resistance and dynamic fatigue resistance possessed by the conjugated diene rubber. It comprises 90 to 40 % by weight of a high molecular weight ethylene-propylene-diene rubber (A) having an ethylene content of 73 to 85 mol. %, a limiting viscosity number Ä eta Ü of 2.5 to 5.0 dl/g as measured at 135 DEG C in decalin and an iodine value of 15 to 35; and 10 to 60 % by weight of a low molecular weight ethylene-propylene-diene rubber (B) having an ethylene content of 73 to 85 mol. %, a limiting viscosity number Ä eta Ü of 0.15 to 0.8 dl/g as measured at 135 DEG C in decalin and an iodine value of 15 to 35, the Mooney viscosity, ML 1+4(100 DEG C), of which is in the range of 50 to 120. The invention also provides an elastomer composition comprising this rubber, a conjugated diene rubber and an inorganic filler, and a vulcanized rubber prepared by the co-vulcanization of this composition. The vulcanized rubber is suited for use in various fields, such as tire, automobile parts, general engineering parts and civil engineering building materials, especially in the fields where dynamic fatigue resistance is demanded. |