abstract |
The present invention provides a poly(meth)acrylate-based viscosity index improver comprising a polymer chain comprising a structural unit represented by the following formula (1), wherein a weight-average molecular weight Mw is 100000 or more, and a ratio of the weight-average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, is 1.6 or less.n n[In the formula (1), R 1 represents hydrogen or a methyl group, and R 2 represents a C1 to C36 alkyl group.] |