A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100° C. of 9.3 to 11.0 mm.sup.2/s.

A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100° C. of 9.3 to 11.0 mm.sup.2/s.

A lubricating oil composition containing a phosphite ester derivative (A) having at least one alkyl group having 1 to 20 carbon atoms in which one —CH.sub.2— group is substituted with a —S— group, and a thiadiazole derivative (B). A method of lubricating an electric drive unit with the lubricating oil composition and an electric drive unit including the lubricating oil composition.

A lubricating oil composition containing a phosphite ester derivative (A) having at least one alkyl group having 1 to 20 carbon atoms in which one —CH.sub.2— group is substituted with a —S— group, and a thiadiazole derivative (B). A method of lubricating an electric drive unit with the lubricating oil composition and an electric drive unit including the lubricating oil composition.

Disclosed is food-grade lubricating grease and a method for preparing the same, belonging to the technical field of lubricating grease. The food-grade lubricating grease is prepared from the following components in percentage by mass: 75% to 85% of food-grade white oil, 6% to 16% of stearic acid, 2.0% to 3.0% of benzoic acid, 4.7% to 8.7% of aluminum isopropoxide, 1.0% to 1.5% of water and 1.0% to 7.0% of nano-PTFE, and has good extreme-pressure, abrasion-resistant and friction-reduction properties, a last non-seizure load (P.sub.B) reaching 411.6 N, a sintering load (P.sub.D) reaching 1,960 N, and a friction coefficient reduced by 18.5%. The lubricating grease can be used for a food production industry and in household food appliances, the service life of a device and the service life of the food-grade lubricating grease are effectively prolonged, and meanwhile, food security is guaranteed to a certain degree.

A polymer composition, in which a differential distribution value in a differential molecular weight distribution curve of the polymer composition, as measured by gel permeation chromatography, satisfies Equation 1 and a maximum value of a normalized back-scattering intensity of a 35 wt % base oil solution of the polymer composition, where a size q of a scattering vector of small-angle X-ray scattering at 25° C. is in a range of 0.07 nm.sup.−1 or more and 2 nm.sup.−1 or less, is 40 cm.sup.−1 or more.

A polymer composition, in which a differential distribution value in a differential molecular weight distribution curve of the polymer composition, as measured by gel permeation chromatography, satisfies Equation 1 and a maximum value of a normalized back-scattering intensity of a 35 wt % base oil solution of the polymer composition, where a size q of a scattering vector of small-angle X-ray scattering at 25° C. is in a range of 0.07 nm.sup.−1 or more and 2 nm.sup.−1 or less, is 40 cm.sup.−1 or more.

A grease composition comprising a thickener and a lubricating base oil, wherein the lubricating base oil has a viscosity in the range of from 5-1000 cSt (at 40° C.). The thickener is present in an amount of 5-40 wt. %, based on total weight of the grease composition. The thickener comprises an ester terminated oligomer which has the general formula: “R1—O—[CO—R2—CO—NH—R3—NH—CO—R2—CO]n-O—R1”. “R1” represents a hydrocarbon group containing 4-22 carbon atoms. “R2” represents a hydrocarbon group containing 4-42 carbon atoms. “R3” represents a hydrocarbon group containing 2-9 carbon atoms. “n” represents an integer in the range of 1-20. The weight ratio between the lubricating base oil and the ester terminated oligomer (oil/oligomer) is larger than 1. The grease composition can be used for lubricating a mechanical component having a metal surface and/or for protecting a mechanical component having a metal surface against corrosion, wear and/or fretting.

A grease composition comprising a thickener and a lubricating base oil, wherein the lubricating base oil has a viscosity in the range of from 5-1000 cSt (at 40° C.). The thickener is present in an amount of 5-40 wt. %, based on total weight of the grease composition. The thickener comprises an ester terminated oligomer which has the general formula: “R1—O—[CO—R2—CO—NH—R3—NH—CO—R2—CO]n-O—R1”. “R1” represents a hydrocarbon group containing 4-22 carbon atoms. “R2” represents a hydrocarbon group containing 4-42 carbon atoms. “R3” represents a hydrocarbon group containing 2-9 carbon atoms. “n” represents an integer in the range of 1-20. The weight ratio between the lubricating base oil and the ester terminated oligomer (oil/oligomer) is larger than 1. The grease composition can be used for lubricating a mechanical component having a metal surface and/or for protecting a mechanical component having a metal surface against corrosion, wear and/or fretting.

This disclosure relates to a lubricating oil (e.g., gear oil) for use in an electric or hybrid vehicle. The lubricating oil has a composition including one or more lubricating oil base stocks as a major component, and one or more lubricating oil additives, as a minor component. The one or more lubricating oil base stocks include at least one Group IV base oil, or at least one Group V base oil. The lubricating oil has a kinematic viscosity (KV.sub.100) from 1 cSt to 7 cSt at 100° C. as determined by ASTM D-445, and an electrical conductivity at room temperature of less than 15,000 pS/m as determined by ASTM D-2624. This disclosure also relates to methods for producing a lubricating oil for a transmission, gear train, gear set, gear box, or gears of an electric vehicle powertrain and methods for improving energy efficiency, while maintaining or improving wear control.