Abstract: A lubricant composition for a machining tool, containing: a lubricating base oil; and based on a total amount of the composition, 0.05 to 5% by mass of a phosphoric acid ester represented by (R1O)3P?O: wherein R1 represents any of an aryl group having 6 to 15 carbon atoms and a saturated hydrocarbon group having 1 to 20 carbon atoms, and each R1 may be the same or different; 0.01 to 2% by mass of an acidic phosphoric acid ester represented by (R2O)nP(?O)(OH)(3-n): wherein R2 represents an alkyl group having 4 to 20 carbon atoms, n represents 1 or 2, and R2 may be the same or different; and 0.5% by mass to 5% by mass of a sulfur compound.

Abstract: The invention provides a lubricating oil composition comprising a lubricating base oil with a kinematic viscosity at 100° C. of 1-10 mm2/s, a % Cp; of 70 or greater and a % CA of no greater than 2 and a viscosity index improver having a weight-average molecular weight of 100,000 or greater and a ratio of weight-average molecular weight to PSSI of 1.0×104 or greater, at 0.1-50% by mass based on the total amount of the composition, and having a kinematic viscosity at 100° C. of 9.0-12.5 mm2/s and a HTHS viscosity at 150° C. of 2.8 mPa·s or greater. It further provides a lubricating oil composition comprising a lubricating base oil with a kinematic viscosity at 100° C. of 1-6 mm2/s, a % Cp of 70 or greater and a % CA of no greater than 2, a hydrocarbon-based viscosity index improver with a PSSI of no greater than 20, and a poly(meth)acrylate-based viscosity index improver.

Abstract: The lubricating oil composition of the invention comprises a lubricating base oil with a kinematic viscosity at 100° C. of 1-20 mm2/s, and a viscosity index improver having a ratio M1/M2 of 0.20 or greater, between the total area of the peaks between chemical shifts of 36-38 ppm M1 and the total area of the peaks between chemical shifts of 64-66 ppm M2, with respect to the total area of all of the peaks, in the spectrum obtained by 13C-NMR. The lubricating oil composition of the invention has excellent effects, with a sufficiently high HTHS viscosity at 150° C., and a sufficiently low kinematic viscosity at 40° C., a sufficiently low kinematic viscosity at 100° C. and a sufficiently low HTHS viscosity at 100° C.

Abstract: A lubricant composition for a machining tool, containing: a lubricating base oil; and based on a total amount of the composition, 0.05 to 5% by mass of a phosphoric acid ester represented by (R1O)3P?O: wherein R1 represents any of an aryl group having 6 to 15 carbon atoms and a saturated hydrocarbon group having 1 to 20 carbon atoms, and each R1 may be the same or different; 0.01 to 2% by mass of an acidic phosphoric acid ester represented by (R2O)nP(?O)(OH)(3-n): wherein R2 represents an alkyl group having 4 to 20 carbon atoms, n represents 1 or 2, and R2 may be the same or different; and 0.5% by mass to 5% by mass of a sulfur compound.

Abstract: A lubricant oil composition comprising: a lubricant base oil whose kinematic viscosity at 100° C. is 1 to 6 mm2/s, % Cp is not less than 70, and % CA is not more than 2; a first viscosity index improver in which the ratio A/B of a viscosity increasing effect A in the equation (1) to a viscosity increasing effect B in the equation (2) when added to the lubricant base oil is a value of not less than 4.5, and a PSSI is not more than 30; and a second viscosity index improver in which the ratio A/B when added to the lubricant base oil is a value less than 4.5: A=X?X0??(1) B=Y?Y0??(2) wherein A represents a viscosity increasing effect of the kinematic viscosity at 100° C., B represents a viscosity increasing effect of the HTHS viscosity at 150° C., X represents a kinematic viscosity at 100° C. of a mixture of the lubricant base oil with 3% by mass of the first or second viscosity index improver, X0 represents a kinematic viscosity at 100° C. of the lubricant base oil, Y represents an HTHS viscosity at 150° C.

Abstract: A lubricating oil composition comprising: a lubricating base oil comprising a first lubricating base oil component having a urea adduct value of not greater than 4% by mass, a kinematic viscosity at 40° C. of 14-25 mm2/s and a viscosity index of 120 or higher and a second lubricating base oil component having a kinematic viscosity at 40° C. of less than 14 mm2/s, wherein the content of the first lubricating base oil component is 10-99% by mass and the content of the second lubricating base oil component is 1-50% by mass, based on the total amount of the lubricating base oil; and a viscosity index improver, the lubricating oil composition having a kinematic viscosity at 100° C. of 4-12 mm2/s and a viscosity index of 200-350.

Abstract: The lubricating oil composition of the invention comprises a lubricating base oil with a kinematic viscosity at 100° C. of 1-20 mm2/s, and a viscosity index improver having a ratio M1/M2 of 0.20 or greater, between the total area of the peaks between chemical shifts of 36-38 ppm M1 and the total area of the peaks between chemical shifts of 64-66 ppm M2, with respect to the total area of all of the peaks, in the spectrum obtained by 13C-NMR. The lubricating oil composition of the invention has excellent effects, with a sufficiently high HTHS viscosity at 150° C., and a sufficiently low kinematic viscosity at 40° C., a sufficiently low kinematic viscosity at 100° C. and a sufficiently low HTHS viscosity at 100° C.

Abstract: The invention provides a lubricating oil composition comprising a lubricating base oil with a kinematic viscosity at 100° C. of 1-10 mm2/s, a % Cp; of 70 or greater and a % CA of no greater than 2 and a viscosity index improver having a weight-average molecular weight of 100,000 or greater and a ratio of weight-average molecular weight to PSSI of 1.0×104 or greater, at 0.1-50% by mass based on the total amount of the composition, and having a kinematic viscosity at 100° C. of 9.0-12.5 mm2/s and a HTHS viscosity at 150° C. of 2.8 mPa·s or greater. It further provides a lubricating oil composition comprising a lubricating base oil with a kinematic viscosity at 100° C. of 1-6 mm2/s, a % Cp of 70 or greater and a % CA of no greater than 2, a hydrocarbon-based viscosity index improver with a PSSI of no greater than 20, and a poly(meth)acrylate-based viscosity index improver.

Abstract: A lubricant oil composition comprising: a lubricant base oil whose kinematic viscosity at 100° C. is 1 to 6 mm2/s, % Cp is not less than 70, and % CA is not more than 2; a first viscosity index improver in which the ratio A/B of a viscosity increasing effect A in the equation (1) to a viscosity increasing effect B in the equation (2) when added to the lubricant base oil is a value of not less than 4.5, and a PSSI is not more than 30; and a second viscosity index improver in which the ratio A/B when added to the lubricant base oil is a value less than 4.5: A=X?X0 ??(1) B=Y?Y0 ??(2) wherein A represents a viscosity increasing effect of the kinematic viscosity at 100° C., B represents a viscosity increasing effect of the HTHS viscosity at 150° C., X represents a kinematic viscosity at 100° C. of a mixture of the lubricant base oil with 3% by mass of the first or second viscosity index improver, X0 represents a kinematic viscosity at 100° C.

Abstract: A lubricating oil composition comprising: a lubricating base oil comprising a first lubricating base oil component having a urea adduct value of not greater than 4% by mass, a kinematic viscosity at 40° C. of 14-25 mm2/s and a viscosity index of 120 or higher and a second lubricating base oil component having a kinematic viscosity at 40° C. of less than 14 mm2/s, wherein the content of the first lubricating base oil component is 10-99% by mass and the content of the second lubricating base oil component is 1-50% by mass, based on the total amount of the lubricating base oil; and a viscosity index improver, the lubricating oil composition having a kinematic viscosity at 100° C. of 4-12 mm2/s and a viscosity index of 200-350.

Abstract: The present invention provides a lubricating oil composition improved in fuel-saving properties by reducing lubrication resistance within the same viscosity grade oils. The lubricating oil composition comprises a lubricating base oil and a viscosity index improver with a PSSI of 30 or lower blended such that the viscosity index of the composition is 160 or greater and the 100° C. kinematic viscosity loss after shearing is 15 percent or less.

Abstract: A bicyclic conjugated diene polymer obtained by polymerizing a monomer (M) comprising at least one kind of bicyclic conjugated diene monomer represented by formula (I), and a bicyclic conjugated diene copolymer obtained by copolymerizing monomer (M) with at least one kind of unsaturated compound other than said monomer: wherein, R1 to R6 are the same or different and are each hydrogen, halogen, or alkyl or halogenated alkyl of 1 to 20 carbon; n and m are each an integer of from 0 to 10; X1, X2, Y1 and Y2 are the same or different from each other and are each hydrogen, halogen or alkyl or halogenated alkyl of 1 to 20 carbon; and, when m or n is 2 or more, each of mX1's, mX2's, nY1's and nY2's are the same or different.

Abstract: A bicyclic conjugated diene polymer obtained by polymerizing a monomer (M) comprising at least one kind of bicyclic conjugated diene monomer represented by formula (I), and a bicyclic conjugated diene copolymer obtained by copolymerizing monomer (M) with at least one kind of unsaturated compound other than said monomer: wherein, R1 to R6 are the same or different and are each hydrogen, halogen, or alkyl or halogenated alkyl of 1 to 20 carbon; n and m are each an integer of from 0 to 10; X1, X2, Y1 and Y2 are the same or different from each other and are each hydrogen, halogen or alkyl or halogenated alkyl of 1 to 20 carbon; and, when m or n is 2 or more, each of mX1's, mX2's, nY1's and nY2's are the same or different.