The present invention relates to a grease composition which can impart excellent durability to a bearing used under a high-speed rotation condition with a DN value of 100,000 or more, wherein the grease composition contains a base oil (A) and a urea-based thickener (B), and particles containing the urea-based thickener (B) in the grease composition satisfy requirement (I) that the particles have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method. The grease composition is used for a bearing used under a high-speed rotation condition with a DN value of 100,000 or more.

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a boron-containing additive, a boron-free dispersant, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 of less than 2.7 mPa s. The instant lubricating compositions disclosed herein may accomplish one or more of the following improve fuel economy, reduce corrosion, reduce oxidation, improve cleanliness, and improve wear performance of an internal combustion engine.

Provided herein are polyolefin dispersants, as well as methods for producing polyolefin dispersants. The polyolefin dispersants can be defined by the formula below ##STR00001## where R.sup.x is cationic initiator residue; R.sup.a is a polyolefin group; R.sup.1 and R.sup.2 are each, independently in each —(CR.sup.1R.sup.2) unit, H, alkyl, alkoxy, or alkylaryl; R.sup.3 and R.sup.4 are each, independently, H, alkyl, or alkoxy; m is an integer from 1 to 20; n is an integer from 1 to 6; r is an integer from 1 to 4; Y is a polyvalent amine linker comprising one or more tertiary amines, wherein the polyvalent amine linker does not include a primary amine or a secondary amine; and A is absent, or comprises a dispersive moiety.

A lubricating oil composition including: a lubricant base oil; (A) a triazole metal deactivator in an amount of 0.005 to 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition; and (B1) a succinimide compound represented by the following general formula (1) in an amount of 0.0005 to 0.02 mass % in terms of nitrogen on the basis of the total mass of the composition: ##STR00001##
wherein in the general formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-36 linear or branched chain alkyl or alkenyl group, and at least one of R.sup.1 and R.sup.2 is a C8-36 linear or branched chain alkyl or alkenyl group, and n represents an integer of 1 to 10.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.

A complex including an active ingredient, and a surfactant. The active ingredient is one or more less-oil-soluble substances selected from the group consisting of a hardly-oil-soluble substance and an oil-insoluble substance, and the one or more less-oil-soluble substances function as an additive for lubricating oil. A method of making the complex.

Provided is a water-soluble metalworking oil comprising a base oil (A) comprising oil-soluble polyalkylene glycol (A1), wherein a total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 60% by mass based on the total amount excluding water.

A water-soluble metalworking oil may include 0.7% by mass or more of 2-phenoxyethanol (A), based on the total water-soluble metalworking oil mass. A content of petroleum sulfonate may be less than 10 parts by mass, based on 100 parts by mass of the 2-phenoxyethanol (A). The 2-phenoxyethanol (A) may be present in a range of from 0.7 to less than 5.0% by mass. The water-soluble metalworking oil may further include: an amine, a fatty acid (C), and/or a nonionic surfactant (D).

Provided is a an additive or composition for imparting lubricity which has high lubricity, is excellent in low-corrosion property, low-temperature fluidity, thermal conductivity, thermal stability, and oxidative stability, and has high flashing point. The lubricant according to the present invention is an additive or composition, wherein the following components (A) an amine or an ammonium compound; and (B) an acid or a salt thereof, have been added therein, wherein at least one of the components (A) and (B) contains a hydrogen-bonding functional group.