PROCESS OIL FOR RUBBER AND RUBBER COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a process oil for rubber which can give a rubber excellent in initial rubber physical properties (physical properties in ordinary state) and also excellent in heat resistance, and to provide a rubber composition containing this oil. SOLUTION: The process oil contains (a) 25-100 wt.% of a mineral oil-based vacuum distillation residual oil having a viscosity-gravity constant of 0.790-0.875 and (b) 0-75 wt.% of a mineral oil which contains a polycyclic aromatic compound by less than 3 wt.% and has a flash point of 200 deg.C or more. The rubber composition incorporates 10-25 wt.% of the above process oil in the rubber, based on the total amount of the rubber composition.