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: The present invention provides a lubricating oil composition having an extremely high viscosity index and a low coefficient of traction as a low coefficient of fluid friction in an elastohydrodynamic lubrication which is excellent in saving of energy and reduction in fuel consumption. The lubricating oil composition according to the present invention includes the following components (A) and (B): (A) a low-viscosity synthetic oil comprising a compound containing ether bond(s) 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); and (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 of the invention contains: (a) a base oil for a lubricating oil having a kinematic viscosity at 100 degrees C. in a range of 2 mm2/s to 10 mm2/s; and (b) a poly-alpha-olefin having a kinematic viscosity at 100 degrees C. in a range of 15 mm2/s to 300 mm2/s, the poly-alpha-olefin (b) being produced using a metallocene catalyst, a content of the poly-alpha-olefin (b) being 20 mass % or more based on a total amount of the composition.

Abstract: There is provided lubricants for power transmission which exhibit not only a high coefficient of traction but also a high flash point. The lubricants for power transmission according to the present invention contains an alicyclic alcohol carboxylic diester compound represented by the general formula (1): R1—CO—O—(X1)m—Z—(X2)n—O—CO—R2??(1) wherein Z is a cycloalkylene group having 3 to 12 carbon atoms; R1 and R2 are each independently a chain hydrocarbon group having 3 to 20 carbon atoms; X1 and X2 are each independently a linear or branched alkylene group having 1 to 5 carbon atoms; and m and n are respectively an integer of 0 or 1.

Abstract: Provided is a lube base oil capable of giving a lubricating oil composition which has a low viscosity, but is small in evaporation amount has a low coefficient of friction and excellent adaptability for organic materials, and is suitable for use in a high-temperature atmosphere and a lubricating oil composition containing the lube base oil and having such properties. The lube base oil comprises as a main component an ether compound represented by the general formula R1—O—R2 (wherein R1 and R2 each independently represents an alkyl group having 2 to 26 carbon atoms) has a kinematic viscosity at 100° C. of 3.5 mm2/s or lower, has a mass loss through evaporation as measured through Noack test (at 250° C.; 1 hour) of 30% by mass or lower and/or has a flash point of 200° C. or higher, and has an aniline point of 60° C. or higher.

Abstract: Provided is a lube base oil capable of giving a lubricating oil composition which has a low viscosity, but is small in evaporation amount has a low coefficient of friction and excellent adaptability for organic materials, and is suitable for use in a high-temperature atmosphere and a lubricating oil composition containing the lube base oil and having such properties. The lube base oil comprises as a main component an ether compound represented by the general formula R1—O—R2 (wherein R1 and R2 each independently represents an alkyl group having 2 to 26 carbon atoms) has a kinematic viscosity at 100° C. of 3.5 mm2/s or lower, has a mass loss through evaporation as measured through Noack test (at 250° C.; 1 hour) of 30% by mass or lower and/or has a flash point of 200° C. or higher, and has an aniline point of 60° C. or higher.

Abstract: There is provided lubricants for power transmission which exhibit not only a high coefficient of traction but also a high flash point. The lubricants for power transmission according to the present invention contains an alicyclic alcohol carboxylic diester compound represented by the general formula (1): R1—CO—O—(X1)m-Z-(X2)n—O—CO—R2 ??(1) wherein Z is a cycloalkylene group having 3 to 12 carbon atoms; R1 and R2 are each independently a chain hydrocarbon group having 3 to 20 carbon atoms; X1 and X2 are each independently a linear or branched alkylene group having 1 to 5 carbon atoms; and m and n are respectively an integer of 0 or 1.

Abstract: There is disclosed an engine oil composition which comprises as the essential components (a) a base oil comprising either or both of a mineral oil and a synthetic oil, (B) a boron compound derivative of alkenylsuccinimide, (C) an alkaline earth metal salt of salicylic acid and (D) either or both of a molybdenum dithiophosphate and a molybdenum dithiocarbamate. The above engine oil composition can effectively be used as a lubricating engine oil in automobiles and various industrial internal combustion engines by virtue of reduced friction loss of an engine by the use thereof and its low friction properties both in the early stages of use and after being used for a certain period of time.

Abstract: The present invention relates to a lubricating oil composition comprising:(A) a mineral oil having a kinematic viscosity at 100.degree. C. of 1 to 50 centistokes and a viscosity index of at least 60,(B) 0.5 to 20% by weight based on the total weight of the composition of an ethylene-.alpha.-olefin copolymer having a number average molecular weight of 800 (inclusive) to 5,000 (exclusive),(C) 0.05 to 20% by weight based on the total weight of the composition of polymethacrylate having a number average molecular weight of 10,000 to 250,000 or a mixture of said polymethacrylate and an olefin copolymer, and(D-I) 1 to 20% by weight based on the total weight of the composition of a detergent-dispersant and/or an antioxidant, or(D-II) 0.5 to 20% by weight based on the total weight of the composition of at least one member selected from the group consisting of a extreme pressure agent, an anti-wear agent and an oiliness agent.