Title:
VISCOSITY INDEX IMPROVER COMPOSITION AND LUBRICATION OIL COMPOSITION
Document Type and Number:
Japanese Patent JP2016065222
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a viscosity index improver that gives an excellent shear stability to a lubrication oil composition, gives a low HTHS viscosity to the lubrication oil composition, and hardly increases the low temperature viscosity of the lubrication oil composition.SOLUTION: Provided is a viscosity index improver composition comprising a base oil, and a (co)polymer (A) having a (meth)acrylate monomer comprising a branched alkyl group of 10 or more carbon atoms, as a constitutional unit, which contains the (co)polymer (A) whose degree of branching (CB) of the branched alkyl group in the (meth)acrylate monomer, derived from formula (1), satisfies the following formula (2) and formula (3) derived from an absolute value (ΔSP) of a solubility parameter difference between the solubility parameters of (A) and the base oil. (CB)=Σ[(BC)/(AC)×(BWT)]/(LCWT) (1), 0.83×(ΔSP)-0.75<(CB) (2), and 0.25≤(CB)<0.5 (3).SELECTED DRAWING: None
Inventors:
NAKADA SHIGEKUNI
Application Number:
JP2015174610A
Publication Date:
April 28, 2016
Filing Date:
September 04, 2015
Export Citation:
Assignee:
SANYO CHEMICAL IND LTD
International Classes:
C10M171/00; C10M101/02; C10M145/14; C10M149/10
Domestic Patent References:
| JP2014141577A | 2014-08-07 | |||
| JP2004124080A | 2004-04-22 |