An oil composition comprising a first component having pendant groups and a second component but free of a third component and process for making such oil composition, where a single molecule of the third component can form large shearable stable complex structure with two molecules of the first component via van der Waals force between pendant groups and the terminal carbon chains, and a single molecule of the second component is capable of adjoining no more than one molecule of the first type. The oil composition has high shear stability making it suitable for use in lubricants subject to repeated high shear stress events.

A grease composition includes alkylnaphthalene as base oil and a urea compound as thickening agent. The thickening agent is an alicyclic aliphatic diurea compound contained at a ratio of 4 mass % to 10 mass % based on the total mass of the grease composition. A pivot assembly bearing device is provided with rolling bearings filled with the above grease composition. A hard disk drive device is provided with a swing arm which is swingably supported by the pivot assembly bearing device.

This disclosure relates to cold cranking simulator viscosity (CCSV) reducing base stocks that allow flexibility for low viscosity SAE engine oil grades (e.g., 5 W and 0 W) to meet demanding low temperature viscosity requirements while maintaining a higher base oil viscosity for improved wear protection. The CCSV-reducing base stocks include mono-esters derivable from a Guerbet alcohol and a monocarboxylic acid. The disclosure also relates to lubricating oil formulations containing the CCSV-reducing base stocks, and a method for determining the CCSV-reducing efficacy of a base stock.

A grease composition including: a base oil, a thickener, and 0.2 wt % or more of a dispersing agent. The dispersing agent includes at least one of a metal salt of a carboxylic acid, a metal salt of a polycarboxylic acid, and a copolymer of a carboxylic acid metal salt and a hydrocarbon compound, and the dispersing agent has an average particle diameter of 0.5 m or more and 5 m or less. The metal salt of the carboxylic acid, the metal salt of the polycarboxylic acid, and the carboxylic acid metal salt forming the copolymer of the carboxylic acid metal salt and the hydrocarbon compound may be an alkali metal salt including at least one of a sodium salt, a lithium salt and a potassium salt, or an alkali earth metal salt including at least one of a magnesium salt and a calcium salt.

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.

A use of a hemimellitic acid ester of formula I as a base oil a lubricant composition for lubricating tribological systems. In some embodiments, R.sub.1, R.sub.2 and R.sub.3, are independently of one another: a C.sub.5 to C.sub.20 aromatic group, a C.sub.5 to C.sub.20 cycloalkyl group, an unsubstituted, branched or unbranched C.sub.1 to C.sub.20 alkyl group, and/or a C.sub.1 to C.sub.5 alkyl group comprising at least one substituent selected from the group consisting of cycloalkyl groups and aromatic groups. In some embodiments, the hemimellitic acid ester of formula I is provided as a mixture of different compounds of formula I and/or the hemimellitic acid ester of formula I comprises groups R.sub.1, R.sub.2 and R.sub.3 at least partially differing from one another.

A lubricant composition is provided that has reduced deposit formation and a low evaporation allowing for improved performance in high temperature applications relative to conventional high temperature lubricants. The high temperature lubricant composition includes a base oil, wherein the base oil includes at least one polyol ester and at least one pyromellitate ester. In some embodiments, the lubricant composition further includes one or more additives selected from the group of an extreme-pressure additive, an anti-wear additive, an anti-rust additive, a corrosion inhibitor, and an antioxidant, or a combination thereof. Further provided are methods for lubricating an apparatus using the lubricant composition, methods for improving the operational lubrication of a conventional high temperature lubricant, and methods of preparing the high temperature lubricant composition of the present invention.

This disclosure relates to a low viscosity lubricating turbine oil having a composition comprising a lubricating oil base stock, as a major component, and one or more lubricating oil additives, as minor components. The lubricating turbine oil has a kinematic viscosity of about 16 cSt to about 22 cSt at 40 C., a density of about 0.8 g/ml to about 0.9 g/ml, and an absolute evaporation loss at 150 C. of less than about 4%. This disclosure also relates to a method for improving energy efficiency in a turbomachine lubricated with the low viscosity lubricating turbine oil. This disclosure further relates to a method for improving energy efficiency while maintaining or improving deposit control and lubricating oil additive solvency in a turbomachine lubricated with the low viscosity lubricating turbine oil. This disclosure yet further relates to a method for improving solubility, compatibility and dispersancy of polar additives in the low viscosity lubricating turbine oil.

This disclosure relates to a low viscosity lubricating turbine oil having a composition comprising a lubricating oil base stock, as a major component, and one or more lubricating oil additives, as minor components. The lubricating turbine oil has a kinematic viscosity of about 16 cSt to about 22 cSt at 40 C., a density of about 0.8 g/ml to about 0.9 g/ml, and an absolute evaporation loss at 150 C. of less than about 4%. This disclosure also relates to a method for improving energy efficiency in a turbomachine lubricated with the low viscosity lubricating turbine oil. This disclosure further relates to a method for improving energy efficiency while maintaining or improving deposit control and lubricating oil additive solvency in a turbomachine lubricated with the low viscosity lubricating turbine oil. This disclosure yet further relates to a method for improving solubility, compatibility and dispersancy of polar additives in the low viscosity lubricating turbine oil.

This disclosure provides a process for producing vinylidene dimer derivatives by subjecting one or more vinylidene dimers and one or more carbonyl-containing compounds to a carbonyl-ene reaction, optionally in the presence of a catalyst, to produce one or more vinylidene dimer derived alcohols. This disclosure also provides a process for producing vinylidene dimer derivatives by reacting one or more vinylidene dimers with one or more carbonyl-containing compounds, optionally in the presence of a catalyst, to produce one or more vinylidene dimer derived alcohols. This disclosure further provides vinylidene dimer derivatives (e.g., vinylidene dimer derived alcohols and esters) produced by these processes. This disclosure still further provides for hydrogenating/reacting the vinylidene dimer derived alcohols with acids or anhydrides to produce vinylidene dimer derived esters. This disclosure yet further relates to lubricating ester oil base stocks, and lubricating oils containing the lubricating ester oil base stocks.