摘要:
The present invention provides a poly(meth)acrylate-based viscosity index improver comprising a core portion and three or more arm portions, wherein each of the arm portions consists of a polymer chain comprising a structural unit represented by the following formula (1), and one end of the polymer chain is bonded to the core portion, and 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. [R1 represents hydrogen or a methyl group, and R2 represents a C1 to C36 alkyl group.]
摘要:
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) and a structural unit represented by the following formula (2), wherein Mw is 100000 or more, and Mw/Mn, is 1.6 or less. [R1 represents hydrogen or a methyl group, and R2 represents a group represented by the following formula (3), and R3 represents a C1 to C18 alkyl group that is straight-chain or has a branch having 5 or less carbon atoms. m and n are integers which satisfy m≧5, n≧4, and m+n≦31.]
摘要:
A lubricating oil composition is provided as an engine oil for an internal combustion engine employing heat management. The composition includes (A) a base oil having 100° C. kinematic viscosity of 3.0 to 5.0 mm2/s, (B) a boronated succinimide in an amount of 0.007 mass percent or more as boron and in an amount of 5 mass percent or less as the succinimide ashless dispersant, based on total mass of the composition, (C) a phenol-based antioxidant in an amount of 0.5 mass percent or more, and (D) a viscosity index improver having a ratio of weight average molecular weight and PSSI of 1.2×104 or greater in an amount of 0.1 to 5 percent by mass. The composition has a 150° C. HTHS viscosity of 2.0 to 2.8 mPa·s, a 100° C. HTHS viscosity of 4.8 mPa·s or lower and a viscosity index of 180 or greater.
摘要:
The present invention provides a poly(meth)acrylate-based viscosity index improver comprising a core portion and three or more arm portions, wherein each of the arm portions consists of a polymer chain comprising a structural unit represented by the following formula (1), and one end of the polymer chain is bonded to the core portion, and 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. [R1 represents hydrogen or a methyl group, and R2 represents a C1 to C36 alkyl group.]
摘要:
A lubricating oil composition comprising a lubricating base oil having a kinematic viscosity at 100° C. of 1 to 10 mm2/s, and a poly(meth)acrylate viscosity index improver containing a structural unit represented by the formula (1) in a proportion of 30 to 90 mol % and having a hydrocarbon main chain ratio of 0.18 or less: wherein R1 represents hydrogen or a methyl group, and R2 represents a linear or branched hydrocarbon group having a carbon number of 6 or less.
摘要:
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. [In the formula (1), R1 represents hydrogen or a methyl group, and R2 represents a C1 to C36 alkyl group.]
摘要:
An engine oil composition comprising: a lubricating base oil having a kinematic viscosity at 100° C. of 1 to 5 mm2/s; a poly(meth)acrylate viscosity index improver containing a structural unit represented by the formula (1) in a proportion of 30 to 90 mol % and having a PSSI in an ultrasonic shear test of 15 or less; and a friction modifier, the engine oil composition has a kinematic viscosity at 100° C. of 4 to 8 mm2/s, and an HTHS viscosity at 150° C. of less than 2.6 mPa·s: [wherein R1 represents hydrogen or a methyl group; and R2 represents a linear or branched hydrocarbon group having a carbon number of 6 or less]:
摘要:
A lubricating oil composition comprising a lubricating base oil having a kinematic viscosity at 100° C. of 1 to 10 mm2/s, and a branched poly(meth)acrylate viscosity index improver containing a structural unit represented by the following formula (1) in the proportion of 30 to 90 mol % and having a branching degree of 0.1 to 8.0: wherein R1 represents hydrogen or a methyl group, and R2 represents a linear or branched hydrocarbon group having a carbon number of 6 or less.