| abstract |
(57) [Problem] To provide a viscosity index improver excellent in shear stability. SOLUTION: 1500 parts of toluene, 8075 parts of dodecyl methacrylate, 425 parts of methyl allyl ether, Phenyldithiocarbamic acid benzyl ester 400 Parts, 200 parts of azobisvaleronitrile, and after purging with nitrogen, a polymerization reaction was carried out at 85 ° C. for 4 hours in a sealed state, and the obtained polymer was used as a viscosity index improver. |