A lubricating composition including a polymer blend of a modified styrene-maleic anhydride copolymer and poly(meth)acrylate copolymer effective to maintain a pumpable fluid at low temperatures.

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.

Provided is a lubricant for a gas insulated switchgear, with which properties of a base oil such as heat resistance, evaporation loss, fluidity under a low temperature, and chemical stability (oxidation resistance and HF resistance) are balanced at a level higher than the conventional level, and long service life and high reliability of the gas insulated switchgear are achieved. A lubricant for a gas insulated switchgear according to the present invention, contains: a base oil containing a polyalphaolefin having a kinematic viscosity at 40° C. of 50 mm.sup.2/s or more; and a thickener containing bisamides.

Lubricating compositions comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. The lubricating composition also comprises an antiwear agent. Methods of lubricating an internal combustion engine comprise contacting the internal combustion engine with a lubricating composition comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. Methods of reducing lubricant oxidation and/or corrosion in an internal combustion engine with a lubricating composition comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. The use of a comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative to reduce lubricant oxidation and/or corrosion in an internal combustion engine.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an ashless dispersant. The ashless dispersant may be selected from succinimide compounds prepared from aliphatic or aromatic amines.

The present invention provides, among other things, a process to produce a low molecular weight dispersant polymethacrylate polymer (“LMWDPMA”), and the LMWDPMA itself, along with the use of the LMWDPMA in a lubricating composition, as well as a method for lubricating an internal combustion engine as disclosed herein.

Disclosed herein is an overbased alkaline earth metal hydrocarbyl-substituted salicylate detergent comprising both carbonate and borate moieties and exhibiting the following characteristics: a basicity index of at least 3.8; a ratio of soap content to mass % boron is greater than 55 mmol/kg; a soap content of at least 330 mmol/kg; a TBN, measured according to ASTM D2896, of at least 220 mg KOH/g; and a mass ratio of borate to carbonate from 0.75 to 6.0, wherein the alkaline earth metal comprises calcium and/or magnesium, and the hydrocarbyl substitution comprises 9 to 30 carbon atoms. Methods of making the boron-containing salicylate detergent, specifically to be package-stable, are also disclosed, as well as package-stable lubricant additive package concentrates and lubricating oil compositions containing same.

The present invention provides a refrigerating machine oil composition comprising an ester-based base oil, an epoxy compound, and a carbodiimide compound, the refrigerating machine oil composition being used with a refrigerant containing a fluoropropene in a refrigerating machine comprising a member containing polyethylene terephthalate and/or a member containing hydrogenated acrylonitrile butadiene rubber.

The disclosed technology relates to lubricants for compression ignition internal combustion engines, particularly those demonstrating at least one of improved seals performance, reduced deposit formation, and excellent durability. The present invention provides a low zinc lubricating composition comprising (a) an oil of lubricating viscosity, (b) a borated dispersant, and (c) a metal-free organo-phosphorus anti-wear additive, wherein the lubricating composition is substantially free of a metal containing sulfur coupled alkyl phenol compound. Further, the low zinc lubricating composition contains zinc in an amount less than 600 ppm by weight of the composition.

The present invention relates to a lubricant base stock, lubricant formulations, a method of lubricating a rotating shaft within a stern tube and the use of a lubricant base stock. The base stock and lubricant formulations may be particularly suited for use in aqueous environments (including fresh water or salt water). A lubricant base stock comprising a first (EO)(PO)(EO) block co-polymer and a second (EO)(PO)(EO) block co-polymer which is different from the first (EO)(PO)(EO) block co-polymer in a marine lubricant formulation wherein the lubricant base stock has a density of at least 1028 kg/m.sup.3 at 20° C. and at most 1022 kg/m.sup.3 at 40° C. in particular is provided.