| 摘要 |
The present invention has its object to provide a viscosity index improver having excellent shearing stability, viscosity index improving ability, and low-temperature viscosity characteristics, a lubricant composition containing the viscosity index improver, and a monomer used for producing the viscosity index improver. The present invention relates to a viscosity index improver comprising a copolymer (A) containing a monomer (a) represented by the following formula (1) as a constituent monomer, a lubricant composition containing the viscosity index improver and a base oil, and a monomer composition containing the monomer (a). |
