| 摘要 |
PURPOSE:To lower the low-temp. viscosity of a high-viscosity-index mineral oil contg. an isomerized paraffin by mixing a specific methacrylate copolymer into the oil. CONSTITUTION:A viscosity index improver comprising a copolymer having a wt. average mol.wt. of 10,000-300,000 is obtd. by subjecting 5-30wt.% alkyl methacrylate (A) having a 1-4C alkyl group, an alkyl methacrylate (B) having a 12-13C alkyl group, an alkyl methacrylate (C) having a 14-15C alkyl group, and 0-20wt.% alkyl methacrylate (D) having a 16-18C alkyl group in a wt. ratio of component B to component C of (4/6)-(1/19) to free-radical polymn. in the presence of an azoic or peroxide polymn. catalyst in a mineral oil or other solvent. |
