Abstract: A lubricating oil composition having a fluorescent compound that emits a fluorescent light. The fluorescent compound has a property of deteriorating with relevance to a deterioration of the lubricating oil composition. A deterioration measurement device having a light emitter that emits an irradiation light toward a measurement target object including a fluorescent compound, a light receiver, and a sensor. A deterioration measurement system having a lubricating oil composition and a deterioration measurement device.

Abstract: Provided are a lubricating oil composition excellent in anti-seizing properties and ant-wear properties, containing a base oil containing at least a mineral oil and a sulfur- and phosphorus-containing anti-wear agent, a mass ratio (S/P ratio) of a sulfur atom and a phosphorus atom contained in the composition being 7.5 or more and 16 or less; and a lubrication method and a gear each using the same.

Abstract: The present invention relates to a lubricating oil composition prepared by blending (A) a tertiary amine having a specific structure, (B) a metal-based detergent having a total base number according to a perchloric acid method of 50 mgKOH/g or less, (C) a metal-based detergent having a total base number according to a perchloric acid method of 150 mgKOH/g or more, (D) at least one selected from an acidic phosphate and an acidic phosphite, and (E) a lubricating base oil, which satisfies a requirement (X): the mass ratio of the metal fraction derived from the component (B) to the metal fraction derived from the component (C) (B/C) is 0.60 or less.

Abstract: The present invention relates to a lubricating oil composition prepared by blending (A) a tertiary amine having a specific structure, (B) a metal-based detergent having a total base number according to a perchloric acid method of 50 mgKOH/g or less, (C) a metal-based detergent having a total base number according to a perchloric acid method of 150 mgKOH/g or more, (D) at least one selected from an acidic phosphate and an acidic phosphite, and (E) a lubricating base oil, which satisfies a requirement (X): the mass ratio of the metal fraction derived from the component (B) to the metal fraction derived from the component (C) (B/C) is 0.60 or less.

Abstract: An object of the present invention is to provide a lubricating oil composition having a low viscosity and an extremely high viscosity index as well as an excellent shearing stability. The present invention relates to a lubricating oil composition including the following components (A) to (C): (A) a low-viscosity synthetic oil including a compound containing an ether bond in a molecule thereof and having a kinematic viscosity of less than 10 mm2/s as measured at 40° C., in which a ratio of the number of oxygen atoms to the number of carbon atoms as constituents of the compound (O/C ratio) and the kinematic viscosity (mm2/s) of the compound as measured at 40° C. satisfy the following formula (1): Kinematic Viscosity at 40° C.?12?[(O/C ratio)×30]??(1); (B) a high-viscosity synthetic oil as a hydrocarbon-based synthetic oil having a kinematic viscosity of 40 mm2/s or more as measured at 100° C.

Abstract: An object of the present invention is to provide a lubricating oil composition having a low viscosity and an extremely high viscosity index as well as an excellent shearing stability. The present invention relates to a lubricating oil composition including the following components (A) to (C): (A) a low-viscosity synthetic oil including a compound containing an ether bond in a molecule thereof and having a kinematic viscosity of less than 10 mm2/s as measured at 40° C., in which a ratio of the number of oxygen atoms to the number of carbon atoms as constituents of the compound (O/C ratio) and the kinematic viscosity (mm2/s) of the compound as measured at 40° C. satisfy the following formula (1): Kinematic Viscosity at 40° C.?12?[(O/C ratio)×30]??(1); (B) a high-viscosity synthetic oil as a hydrocarbon-based synthetic oil having a kinematic viscosity of 40 mm2/s or more as measured at 100° C.

Abstract: A lubricating oil composition contains: (A) organopolysiloxane; and (B) at least one of a sulfur compound, a phosphorus compound and a zinc compound, the lubricating oil composition having a kinematic viscosity not less than 1 mm2/s and less than 40.0 mm2/s at 100 degrees C. The lubricating oil composition is favorably usable in mechanical devices such as a hydraulic device, a stationary gear, an automobile transmission, a motor/battery cooling device and a joint.