| 摘要 |
Multirange lubricating oils having high shear stability comprising paraffinic oils as their base and containing, as an additive improving the viscosity index, a mixture of at least two different polymer species, each of said polymer species being composed of monomers selected from the group consisting of (a) esters of methacrylic acid and acrylic acid with linear alcohols having 6 to 15 carbon atoms, (b) esters of methacrylic acid and acrylic acid with linear alcohols having from 16 to 30 carbon atoms, (c) esters of methacrylic acid and acrylic acid with branched alcohols having from 6 to 40 carbon atoms, (d) esters of methacrylic acid and acrylic acid with alcohols having from 1 to 5 carbon atoms, and (e) other monomers, different from (a)-(d), susceptible to free-radical copolymerization, and containing functional groups in the molecule, monomer or monomers (a) being from 0 to 100 mole percent of said polymer species, monomer(s) (b) being from 0 to 10 mole percent, monomers (c), (d) and (e) combined being from 0 to 100 mole percent, and monomers (a) to (e) combined being 100 mole percent of said polymer species, said individual polymer species differing from one another by at least 10 mole percent with respect to their content of component (a). |
