A lubricating oil composition including a base oil (X) having a tertiary carbon atom at a content of 8.0 at % or more based on the total carbon of hydrocarbons and an antioxidant (Y) having an amine-based antioxidant (A), a phenol-based antioxidant (B), and a phosphor-based antioxidant (C). The amine-based antioxidant (A) includes a diphenylamine compound (A1) represented by the following general formula (a1):

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where R.sup.a1 and R.sup.a2, na1 and na2 are defined in the disclosure.

A lubricating oil composition may be capable of satisfactorily exhibiting sludge prevention properties and wear resistance evaluated by scoring resistance and seizure resistance over a long period of time. Such a lubricating oil composition may contain: a base oil (A); a hindered phenol-based antioxidant (B); one or more imide compounds (C) selected from the group consisting of a monoimide compound (C1) and a bisimide compound (C2); and an extreme pressure agent (D), in which the hindered phenol-based antioxidant (B) is 2,6-di-tert-butylphenol, the monoimide compound (C1) is one or more selected from the group consisting of an alkenyl succinic monoimide compound and an alkyl succinic monoimide compound, and the bisimide compound (C2) is one or more selected from the group consisting of an alkenyl succinic bisimide compound and an alkyl succinic bisimide compound.

This ball screw grease composition for a rack-assisted electric power steering contains a thickener, a base oil, and at least one compound selected from the group consisting of a Ca sulfonates, fatty acids, and triglycerides, wherein the kinematic viscosity of the base oil at 40° C. is 4-100 mm2/s, and the worked penetration of the composition is 265-385.

A lubricant composition comprising a base oil; at least one additive; and 0.001-10% by weight, based on the total weight of the lubricant composition, of an organic compound comprising both a polar moiety and a nonpolar moiety, as lubricity improver, wherein the organic compound has a relative permittivity ε.sub.r in the range from 1.5 to 10, and a quotient ∫S.sub.1/∫S.sub.2 for the organic compound is in the range from 1 to 25, wherein ∫S.sub.1 denotes the sum total of the area(s) of the IR absorption band(s) in the wavenumber range of 3100-2750 cm.sup.−1 in an ATR spectrum of the organic compound, and ∫S.sub.2 denotes the sum total of the area(s) of the IR absorption band(s) in the wavenumber range of 1800-1650 cm.sup.−1 in an ATR spectrum of the organic compound.

The present invention relates to conveyor lubricant compositions including an emulsion of a lipophilic compound and also including an emulsifier and/or an anionic surfactant. The present invention also relates to methods employing such lubricant compositions. In an embodiment, the method includes applying the present lubricant composition to a conveyor with a non-energized nozzle.

A non-curable injectable ester containing packing material for use in the repair of leaking valves contains a calcium sulfonate grease containing at least one polyalphaolefin, an ester, an anti-wear/anti-galling agent, a binding/thickening agent and a plasticizing agent.

Disclosed is a lubricating oil composition. The lubricating oil composition contains a lubricating base oil including mineral base oil, 4 to 15 mass % of an ester compound of a monovalent or polyvalent aliphatic carboxylic acid and a monovalent or polyvalent aliphatic alcohol, 400 to 1200 mass ppm of zinc dialkyl dithiophosphate in terms of a phosphorus element, 500 to 3000 mass ppm of a calcium-based detergent in terms of a calcium element, and 50 to 1000 mass ppm of a boron-modified succinimide-based dispersant in terms of a boron element, on the basis of the total amount of the lubricating oil composition.

Some examples of producing water-based drilling fluids including ecofriendly lubricating additives are described. A raw material oil including fatty acids with a short chain alcohol is esterified in the presence of a catalyst to produce alkyl ester products and triglycerides. The alkyl ester products are washed and heated to remove any residual water or the short chain alcohol. A first quantity of the alkyl ester products is mixed with a second quantity of a water-based wellbore drilling fluid.

A water-based lubricating grease composition includes at least 40 wt % water; a salt-based thickener; a polymer-based thickener; and optionally, an inorganic solid-based thickener. A process for preparing the water-based lubricating grease composition may include blending a suitable amount of water with a salt-based thickener to provide a thickened water-based grease, wherein the salt-based thickener is obtained from contacting a base with a fat; and adding a polymer-based thickener to the thickened water-based grease.

A lubricating oil composition according to the present embodiment is a lubricating oil composition to be used in a sliding member coated with hydrogen-containing diamond-like carbon, and contains a base oil and a friction modifier. The friction modifier contains a fatty acid ester of pentaerythritol.