A lubricating composition which, when used with a device for clamping an article, such as a chuck, produces excellent lubricating properties whilst remaining strongly adhered to metal parts in a clamping mechanism of the device and showing enhanced chemical and physical resistance to fluids such as cutting fluids.

A lubricating composition which, when used with a device for clamping an article, such as a chuck, produces excellent lubricating properties whilst remaining strongly adhered to metal parts in a clamping mechanism of the device and showing enhanced chemical and physical resistance to fluids such as cutting fluids.

A lubricant oil composition for automotive gears includes a lubricant base oil including a mineral oil having a kinematic viscosity at 100° C. of 2.0 to 6.5 mm.sup.2/s, a viscosity index of not less than 105 and a pour point of not more than −10° C., and/or a synthetic oil having a kinematic viscosity at 100° C. of 1.0 to 6.5 mm.sup.2/s, a viscosity index of not less than 120 and a pour point of not more than −30° C.; and an ethylene/α-olefin copolymer having an ethylene content of 55 to 85 mol %, a kinematic viscosity at 100° C. of 10 to 200 mm.sup.2/s, a molecular weight distribution of not more than 2.2, and a melting point in the range of −30° C. to −60° C. The lubricant oil composition for automotive gears has a kinematic viscosity at 100° C. of 4.0 to 9.0 mm.sup.2/s.

A lubricant oil composition for automotive gears includes a lubricant base oil including a mineral oil having a kinematic viscosity at 100° C. of 2.0 to 6.5 mm.sup.2/s, a viscosity index of not less than 105 and a pour point of not more than −10° C., and/or a synthetic oil having a kinematic viscosity at 100° C. of 1.0 to 6.5 mm.sup.2/s, a viscosity index of not less than 120 and a pour point of not more than −30° C.; and an ethylene/α-olefin copolymer having an ethylene content of 55 to 85 mol %, a kinematic viscosity at 100° C. of 10 to 200 mm.sup.2/s, a molecular weight distribution of not more than 2.2, and a melting point in the range of −30° C. to −60° C. The lubricant oil composition for automotive gears has a kinematic viscosity at 100° C. of 4.0 to 9.0 mm.sup.2/s.

A lubricant, including, by weight: 80-85 parts of a base oil; 1-2 parts of a methyl-silicone oil; 1-2 parts of polymethacrylate; 2-4 parts of pentaerythritol polyisobutylene succinate; 1-2 parts of di-n-butyl phosphite; 2-3 parts of butylhydroxytoluene; 2-4 parts of an ethylene-propylene copolymer; 1-2 parts of an alkenyl succinate; and 3-5 parts of copper nanoparticles. A method of preparing the lubricant includes: adding the base oil, the methyl-silicone oil, the polymethacrylate, the ethylene-propylene copolymer, the butylhydroxytoluene, the alkenyl succinate to a reactor, and stirring a resulting first mixture under normal temperature and pressure at 300-400 rpm for 3-4 hours, to yield a primary product; and adding the di-n-butyl phosphite, the pentaerythritol polyisobutylene succinate, and the copper nanoparticles to the primary product, and stirring a resulting second mixture at 150-250 rpm for 2-2.5 hours.

A lubricant, including, by weight: 80-85 parts of a base oil; 1-2 parts of a methyl-silicone oil; 1-2 parts of polymethacrylate; 2-4 parts of pentaerythritol polyisobutylene succinate; 1-2 parts of di-n-butyl phosphite; 2-3 parts of butylhydroxytoluene; 2-4 parts of an ethylene-propylene copolymer; 1-2 parts of an alkenyl succinate; and 3-5 parts of copper nanoparticles. A method of preparing the lubricant includes: adding the base oil, the methyl-silicone oil, the polymethacrylate, the ethylene-propylene copolymer, the butylhydroxytoluene, the alkenyl succinate to a reactor, and stirring a resulting first mixture under normal temperature and pressure at 300-400 rpm for 3-4 hours, to yield a primary product; and adding the di-n-butyl phosphite, the pentaerythritol polyisobutylene succinate, and the copper nanoparticles to the primary product, and stirring a resulting second mixture at 150-250 rpm for 2-2.5 hours.

Disclosed is a lubricating oil composition containing a base oil, a viscosity index improver, a molybdenum-based friction modifier, a boron-containing dispersant, and at least two extreme-pressure additives selected from a sulfur-based extreme-pressure additive, a phosphorous-based extreme-pressure additive and a sulfur/phosphorus-based extreme-pressure additive, or a sulfur/phosphorus-based extreme-pressure additive. The base oil is a synthetic oil having a kinematic viscosity at 100° C. of 3 mm.sup.2/s or more and 10 mm.sup.2/s or less, the viscosity index improver is a resin having a number average molecular weight (Mn) of 1,000 or more and 10,000 or less, the mass ratio of boron atoms (B) contained in the boron-containing dispersant to molybdenum atoms (Mo) contained in the molybdenum-based friction modifier, [(B)/(Mo)] is 1 or more and 5 or less, and the mass ratio of sulfur atoms (S) to phosphorus atoms (P) contained in the extreme-pressure additive(s), [(S)/(P)] is 10 or more and 20 or less.

Disclosed is a lubricating oil composition containing a base oil, a viscosity index improver, a molybdenum-based friction modifier, a boron-containing dispersant, and at least two extreme-pressure additives selected from a sulfur-based extreme-pressure additive, a phosphorous-based extreme-pressure additive and a sulfur/phosphorus-based extreme-pressure additive, or a sulfur/phosphorus-based extreme-pressure additive. The base oil is a synthetic oil having a kinematic viscosity at 100° C. of 3 mm.sup.2/s or more and 10 mm.sup.2/s or less, the viscosity index improver is a resin having a number average molecular weight (Mn) of 1,000 or more and 10,000 or less, the mass ratio of boron atoms (B) contained in the boron-containing dispersant to molybdenum atoms (Mo) contained in the molybdenum-based friction modifier, [(B)/(Mo)] is 1 or more and 5 or less, and the mass ratio of sulfur atoms (S) to phosphorus atoms (P) contained in the extreme-pressure additive(s), [(S)/(P)] is 10 or more and 20 or less.

The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.30% by mass or more on the basis of the whole amount of the lubricating oil composition; the metal-based detergent (C) contains a calcium phenate (C1) and a calcium sulfonate (C2), and a mass ratio of the content (Ca.sub.1) of the calcium phenate (C1) as expressed in terms of a calcium atom to the content (Ca.sub.2) of the calcium sulfonate (C2) as expressed in terms of a calcium atom is satisfied with a relation of (1.0≤Ca.sub.1/Ca.sub.2); and the lubricating oil composition has a kinematic viscosity at 100° C. is less than 9.3 mm.sup.2/s and an HTHS viscosity at 150° C. is 2.9 mPa.Math.s or more.

The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.30% by mass or more on the basis of the whole amount of the lubricating oil composition; the metal-based detergent (C) contains a calcium phenate (C1) and a calcium sulfonate (C2), and a mass ratio of the content (Ca.sub.1) of the calcium phenate (C1) as expressed in terms of a calcium atom to the content (Ca.sub.2) of the calcium sulfonate (C2) as expressed in terms of a calcium atom is satisfied with a relation of (1.0≤Ca.sub.1/Ca.sub.2); and the lubricating oil composition has a kinematic viscosity at 100° C. is less than 9.3 mm.sup.2/s and an HTHS viscosity at 150° C. is 2.9 mPa.Math.s or more.