Abstract: A lubricant composition includes a lubricant base oil (A) having a kinematic viscosity at 100° C. of 1 to 10 mm2/s, and an ethylene/?-olefin copolymer (B) in which (B1) the peak top molecular weight is 3,000 to 10,000, (B2) the copolymer shows no melting peak, (B3) the value B is not less than 1.1 and (B4) the kinematic viscosity at 100° C. is 140 to 500 mm2/s. The lubricant composition has a kinematic viscosity at 100° C. of not more than 20 mm2/s, a peak top of molecular weight in the range of 3,000 to 10,000, and a weight fraction of components having a molecular weight not less than 20,000 of 1 to 10% relative to all components having a molecular weight not less than the molecular weight that gives the peak top.

Abstract: The present invention addresses the problem of providing a lubricating oil composition having excellent heat resistance (suppression of discoloration in heating) and tackiness while maintaining excellent viscosity properties of a lubricating oil composition using a ricinolic acid polymer. The present invention provides a copolymer (B) containing structural units (a) derived from ricinolic acid, structural units (b) derived from an aliphatic dicarboxylic acid and structural units (c) derived from a diol having 2 to 10 carbon atoms in a specific ratio and having a specific intrinsic viscosity, and provides a lubricating oil composition containing a base oil and the copolymer (B) and having a mass ratio (mass of (A) /mass of (B)) of the base oil (A) to the copolymer (B) of 60/40 to 99.5/0.5.

Abstract: [Problem] From the points of view of improving the fuel efficiency of automobiles and industrial machines and saving energies thereof, the present invention provides lubricants having outstanding shear stability and low-temperature viscosity characteristics. [Solution] A lubricant composition includes a lubricant base oil (A) having a kinematic viscosity at 100° C. of 1 to 10 mm2/s, and an ethylene/?-olefin copolymer (B) in which (B1) the peak top molecular weight is 3,000 to 10,000, (B2) the copolymer shows no melting peak, (B3) the value B is not less than 1.1 and (B4) the kinematic viscosity at 100° C. is 140 to 500 mm2/s. The lubricant composition has a kinematic viscosity at 100° C. of not more than 20 mm2/s, a peak top of molecular weight in the range of 3,000 to 10,000, and a weight fraction of components having a molecular weight not less than 20,000 of 1 to 10% relative to all components having a molecular weight not less than the molecular weight that gives the peak top.

Abstract: A lubricating oil composition comprising (A) an ethylene/?-olefin copolymer satisfying all of the following requirements (A-1) to (A-3): (A-1) an ethylene structural unit content of 30 to 70% by mol, (A-2) a kinematic viscosity at 100° C. of 20 to 3000 mm2/s, and (A-3) Mw/Mn as measured by GPC of 1 to 2.5, (F) a sulfur-containing compound in which at least one hydrocarbon group adjacent to sulfur is a secondary or tertiary hydrocarbon group, and as an optional component, (G) an ?-olefin polymer having 3 to 6 carbon atoms, and having a kinematic viscosity at 40° C. of 450 to 51,000 mm2/s, a sulfur content of 0.1 to 5 parts by weight, and a component (G) content of 0 to 15 parts by weight. The lubricating oil composition is suitable particularly for gear oil and the like.

Abstract: A lubricating oil composition comprising (A) an ethylene/?-olefin copolymer satisfying all of the following requirements (A-1) to (A-3) : (A-1) an ethylene structural unit content of 30 to 70% by mol, (A-2) a kinematic viscosity at 100° C. of 20 to 3000 mm2/s, and (A-3) Mw/Mn as measured by GPC of 1 to 2.5, (F) a sulfur-containing compound in which at least one hydrocarbon group adjacent to sulfur is a secondary or tertiary hydrocarbon group, and as an optional component, (G) an ?-olefin polymer having 3 to 6 carbon atoms, and having a kinematic viscosity at 40° C. of 450 to 51,000 mm2/s, a sulfur content of 0.1 to 5 parts by weight, and a component (G) content of 0 to 15 parts by weight. The lubricating oil composition is suitable particularly for gear oil and the like.

Abstract: A lubricating oil composition for a power transmission system, which is excellent in both of low-temperature viscosity property and shear stability, is provided. The viscosity modifier of a lubricating oil for a power transmission system according to the present invention comprises an ethylene/?-olefin copolymer (B) having the properties: (B1) an ethylene content in the range of 70 to 85% by mol, (B2) an intrinsic viscosity [?] in the range of 0.2 to 1.0 dl/g, (B3) Mw/Mn not more than 2.4, and (B4) a melting point, as measured by DSC, not higher than 60° C., or no melting point observed.

Abstract: A lubricating oil composition comprising: boron atoms from about 5-75 ppm; and 100% by mass being (i) 90 to 10% of a (co)polymer of specified kinematic viscosity and acid values, primarily derived from 1-decene, (ii) 5 to 85% of a (co)polymer having specified kinematic viscosity and molecular weight distribution, mostly derived from 1-octene, and (iii) 5 to 15% of a fatty acid ester.

Abstract: A viscosity modifier for lubricating oils or an additive composition for lubricating oils, which is excellent in oil-thickening properties and can provide lubricating oil compositions excellent in low-temperature characteristics and handleability at low temperatures; and lubricating oil compositions excellent in low-temperature characteristics and handleability at low temperatures.

Abstract: The present invention provides a lubricating oil composition having excellent low temperature viscosity properties suitable for engine oils for automobiles and industries, gear oils, shock absorber oils, hydraulic fluids and it also provides a lubricating oil for internal-combustion engines formed from the composition. The lubricating oil composition comprises; a lubricating oil base (A) having a kinematic viscosity at 100° C. of 1 to 50 mm2/s and a viscosity index of not less than 80, an ethylene•propylene copolymer (B) having the following properties (B1) to (B4) such that (B1) the ethylene content is from 30 to 75% by weight, (B2) the intrinsic viscosity [?] is from 1.3 to 2.0 dl/g, (B3) the Mw/Mn is not more than 2.4 and (B4) the melting point as measured with DSC is not higher than 30° C., and optionally a pour point depressant (C).

Abstract: A lubricating oil composition for a power transmission system, which is excellent in both of low-temperature viscosity property and shear stability, is provided. The viscosity modifier of a lubricating oil for a power transmission system according to the present invention comprises an ethylene/?-olefin copolymer (B) having the properties: (B1) an ethylene content in the range of 70 to 85% by mol, (B2) an intrinsic viscosity [?] in the range of 0.2 to 1.0 dl/g, (B3) Mw/Mn not more than 2.4, and (B4) a melting point, as measured by DSC, not higher than 60° C., or no melting point observed.

Abstract: The present invention provides a lubricating oil composition having excellent low temperature viscosity properties suitable for engine oils for automobiles and industries, gear oils, shock absorber oils, hydraulic fluids and it also provides a lubricating oil for internal-combustion engines formed from the composition. The lubricating oil composition comprises; a lubricating oil base (A) having a kinematic viscosity at 100° C. of 1 to 50 mm2/s and a viscosity index of not less than 80, an ethylene•propylene copolymer (B) having the following properties (B1) to (B4) such that (B1) the ethylene content is from 30 to 75% by weight, (B2) the intrinsic viscosity [?] is from 1.3 to 2.0 dl/g, (B3) the Mw/Mn is not more than 2.4 and (B4) the melting point as measured with DSC is not higher than 30° C., and optionally a pour point depressant (C).

Abstract: The present invention provides an olefin block copolymer for a viscosity index improver capable of preparing a lubricating oil composition having excellent low temperature properties and excellent balance between viscosity and shear stability, a viscosity index improver and a lubricating oil composition comprising the viscosity index improver. The olefin block copolymer has a Mw/Mn of not more than 1.5, and comprises: (i) a polymer block comprising ethylene and an ?-olefin of 3 to 20 carbon atoms, having a molar ratio (ethylene/?-olefin) of ethylene units to ?-olefin units of from 20/80 to 65/35, a Mw of 50,000 to 2,000,000, and having a slope of an intramolecular composition distribution of absolute value of 0.

Abstract: This invention aims to provide lubricating oil compositions excellent in low-temperature properties, oxidation stability, lubricity at high temperatures and fuel efficiency and also in handling properties at low temperatures, and a viscosity modifier for lubricating oil employable in said lubricating oil compositions. The viscosity modifier for lubricating oil comprises an ethylene/&agr;-olefin copolymer (B) composed of: (i) ethylene, (ii) an &agr;-olefin of 3 or more carbon atoms, and (iii) a higher &agr;-olefin of 4 to 20 carbon atoms wherein the carbon number of (iii) is larger than that of (ii) by one or more, and the ethylene/&agr;-olefin copolymer (B) has the following properties (b-1) and (b-2): (b-1) a content of ethylene (i) is in the range of 40 to 80% by weight, a content of the &agr;-olefin of 3 or more carbon atoms (ii) is in the range of 15 to 59% by weight, and a content of the higher &agr;-olefin of 4 to 20 carbon atoms (iii) is in the range of 0.

Abstract: The present invention provides an olefin block copolymer for a viscosity index improver capable of preparing a lubricating oil composition having excellent low temperature properties and excellent balance between viscosity and shear stability, a viscosity index improver and a lubricating oil composition comprising the viscosity index improver.

Abstract: The lubricating oil composition of the invention comprises a lubricating oil base (A) and a copolymer (B) of ethylene and an &agr;-olefin of 3 to 20 carbon atoms. The copolymer (B) of ethylene and an &agr;-olefin of 3 to 20 carbon atoms is contained in the composition in an amount of 1 to 20% by weight and has the following properties: (1) the ethylene content (E) is in the range of 40 to 77% by weight, (2) the weight-average molecular weight (Mw) in terms of polystyrene, as measured by GPC, is in the range of 80,000 to 400,000, (3) Mw/Mn is not more than 2.4, (4) the melting point (Tm), as measured by DSC, is not higher than 60° C., (5) the ethylene content (E, % by weight) and the melting point (Tm, ° C.), as measured by DSC, satisfy the following relation (I): 3.31×E−186≧Tm  (I), and (6) the intensity ratio, S&agr;&bgr;/S&agr;&agr;, measured by 13C-NMR spectrum is not more than 0.5.

Abstract: This invention aims to provide lubricating oil compositions excellent in low-temperature properties, oxidation stability, lubricity at high temperatures and fuel efficiency and also in handling properties at low temperatures, and a viscosity modifier for lubricating oil employable in said lubricating oil compositions.

Abstract: The present invention provides an olefin block copolymer for a viscosity index improver capable of preparing a lubricating oil composition having excellent low temperature properties and excellent balance between viscosity and shear stability, a viscosity index improver and a lubricating oil composition comprising the viscosity index improver.

Abstract: The present invention is intended to obtain a viscosity modifier for a lubricating oil, by the use of which a lubricating oil composition of excellent low-temperature properties can be obtained, and to obtain a lubricating oil composition of excellent low-temperature properties containing the viscosity modifier. The viscosity modifier for a lubricating oil comprises an ethylene/propylene copolymer (A) having the properties: the density is in the range of 857 to 882 kg/m3, Mw is in the range of 80,000 to 400,000, Mw/Mn is not more than 2.3, and the density (D (kg/m3)) and the melting point (Tm (° C.)) satisfy the relation Tm≦1.247×D−1037; or comprises an ethylene/propylene copolymer (B) having the properties: the ethylene content is in the range of 70 to 79 wt %, Mw is not less than 80,000 and less than 250,000, Mw/Mn is not more than 2.3, Tm is in the range of 15 to 60° C., and the ethylene content (E (wt %)) and the melting point (Tm (° C.)) satisfy the relation 3.

Abstract: A viscosity modifier for lubricating oils which is capable of giving a lubricating oil composition excellent low-temperature properties; and a lubricating oil composition which contains the viscosity modifier and has excellent low-temperature properties. The modifier comprises of any of ethylene/propylene copolymers (A), (B) and (C). The composition comprises a combination of any of the ethylene/propylene copolymers (A), (B) and (C) with a lube base oil (D), and optionally a pour point depressant (E).

Abstract: The lubricating oil composition of the invention comprises a lubricating oil base (A) and a copolymer (B) of ethylene and an &agr;-olefin of 3 to 20 carbon atoms.