An additive package is disclosed for preparing an automotive crankcase lubricating oil composition for an internal combustion engine. The additive package is made by admixing: (i) 50 mass % or less of an oil of lubricating viscosity; (ii) 50 mass % or less of at least one overbased metal detergent, preferably at least one overbased metal hydroxybenzoate detergent; (iii) 50 mass % or less of an oil-soluble block or graft co-polymer of at to least one polymeric block A which is derived from a hydroxycarboxylic acid and at least one polyalkylene block B which is a residue of a polyalkylene glycol, and (iv) optionally, at least one further additive selected from a dispersant, an antioxidant and/or an antiwear agent.

The additive package includes less than 2.00 mass % preferably less than 1.50 mass %, of a friction modifier which is a monoester of a C.sub.5 to C.sub.30 carboxylic acid and which is free of nitrogen.

Component (ii) is preferably an overbased metal hydroxybenzoate detergent.

Component (iii) acts as a friction modifier and can be used as a replacement for a friction modifier such as glycerol monooleate.

The additive package exhibits improved stability.

An additive package is disclosed for preparing an automotive crankcase lubricating oil composition for an internal combustion engine. The additive package is made by admixing: (i) 50 mass % or less of an oil of lubricating viscosity; (ii) 50 mass % or less of at least one overbased metal detergent, preferably at least one overbased metal hydroxybenzoate detergent; (iii) 50 mass % or less of an oil-soluble block or graft co-polymer of at to least one polymeric block A which is derived from a hydroxycarboxylic acid and at least one polyalkylene block B which is a residue of a polyalkylene glycol, and (iv) optionally, at least one further additive selected from a dispersant, an antioxidant and/or an antiwear agent.

The additive package includes less than 2.00 mass % preferably less than 1.50 mass %, of a friction modifier which is a monoester of a C.sub.5 to C.sub.30 carboxylic acid and which is free of nitrogen.

Component (ii) is preferably an overbased metal hydroxybenzoate detergent.

Component (iii) acts as a friction modifier and can be used as a replacement for a friction modifier such as glycerol monooleate.

The additive package exhibits improved stability.

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.

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.

The present disclosure provides a lubricating oil composition which is excellent in metal fatigue life, wear resistance and electrical insulating properties, even when the composition has a reduced viscosity. The lubricating oil composition according to the present disclosure comprises: (A) a lubricating base oil; (B) from 0.6 to 4.0% by weight, based on the total weight of the lubricating oil composition, of a polydiene having a number average molecular weight of from 500 to 3,000 and containing a functional group on at least one end thereof; and (C) at least one selected from a phosphorus-based anti-wear agent and a phosphorus-based extreme pressure agent, the at least one agent being contained in such an amount that the content of phosphorus is from 50 to 500 ppm by weight based on the total weight of the lubricating oil composition.

The present disclosure provides a lubricating oil composition which is excellent in metal fatigue life, wear resistance and electrical insulating properties, even when the composition has a reduced viscosity. The lubricating oil composition according to the present disclosure comprises: (A) a lubricating base oil; (B) from 0.6 to 4.0% by weight, based on the total weight of the lubricating oil composition, of a polydiene having a number average molecular weight of from 500 to 3,000 and containing a functional group on at least one end thereof; and (C) at least one selected from a phosphorus-based anti-wear agent and a phosphorus-based extreme pressure agent, the at least one agent being contained in such an amount that the content of phosphorus is from 50 to 500 ppm by weight based on the total weight of the lubricating oil composition.

The disclosed technology relates to an automotive or industrial gear oil for automotive or industrial gears, as well as axles and bearings, the automotive or industrial gear oil containing an oil of lubricating viscosity, an optional phosphate and/or thiophosphate compound, a particular sulfurized olefin, and a metal thiophosphate compound, such as zinc dialkyldithiophosphate, as well as a method of improving automotive or industrial gear operating efficiency and temperature by lubricating such automotive or industrial gears with the automotive or industrial gear oil.

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.

The invention relates to phosphorous-containing compounds useful as antiwear additive components, lubricant additive compositions and lubricant compositions each comprising such compounds, methods for making and using the same, including methods of lubricating machines and machine parts and methods of extending the useful life of elastomeric seal components of such machines.

The present invention provides a refrigerating machine oil comprising: a base oil; a compound represented by the following formula (1):

##STR00001##

wherein R.sup.1 and R.sup.2 each independently represent a monovalent hydrocarbon group, R.sup.3 represents a divalent hydrocarbon group and R.sup.4 represents a hydrogen atom or a monovalent hydrocarbon group; and an epoxy compound.