The present invention generally relates, in certain aspects, to corrosion inhibiting compositions useful for metalworking fluids, as well as concentrates, additives and metalworking fluids containing such compositions. The invention furthermore relates, in some aspects, to the use of such compositions for providing to a metalworking fluid one or more of anticorrosion performance, antifoam performance, antiwear performance, load carrying capacity, long fluid life, biological stability, lubricity, hard water tolerance, formulation stability.

A grease includes abase oil and a thickener. The base oil is poly--olefin. The thickener is a soap. A viscous transition stress at 25 C. is 300 Pa or more, and a viscous transition stress at 100 C. is 40 Pa or less. A shear viscosity at 25 C. and at a shear rate of 0.1 s.sup.1 is 1.610.sup.6 mPa.Math.s or more, and a shear viscosity at 100 C. and at a shear rate of 10 s.sup.1 is 1.110.sup.4 mPa.Math.s or less.

A calcium sulfonate grease is formed from a base oil of lubricating viscosity, an oil-soluble overbased calcium sulfonate or precursors therefor, a conversion acid, water, and a gelling agent, which is selected from branched aliphatic diols with at least eight carbons, and mixtures thereof.

A surface treatment agent from which a surface layer having an excellent friction resistance can be formed, an article including such a surface layer, and a method for manufacturing such an article are provided. A surface treatment agent according to the present invention contains a fluorine-containing ether compound including a fluoro-polyether chain and a reactive silyl group; a first metallic compound containing a first metallic element; and a second metallic compound containing a second metallic element different from the first metallic element.

[Object] To provide a fluid dynamic bearing filled with a lubricating oil composition containing a base oil and an ionic liquid, and to provide a spindle motor with evaporation being suppressed in the lubricating oil composition provided in the fluid dynamic bearing by incorporating the fluid dynamic bearing in the spindle motor, and thus occurrence of a read-write error in an HDD can be suppressed, and a disk drive device including the spindle motor. [Solution means] A fluid dynamic bearing filled with a lubricating oil composition containing a base oil and an ionic liquid, the ionic liquid including at least one cation selected from the group consisting of tetraalkylammonium cations and at least one anion selected from the group consisting of borate anions represented by Formulas (C-1) to (C-3): (where in the formula, R.sup.9 to R.sup.12 each independently represent a linear or branched alkyl group.)

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Disclosed is a lubricating oil composition which comprises: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100 C. in a range of about 2 to about 50 mm.sup.2/s, (b) an overbased metal salt of an alkyl-substituted phenate detergent, wherein the alkyl group is derived from an isomerized normal alpha olefin having from about 10 to about 40 carbon atoms per molecule and having an isomerization level (I) of the normal alpha olefin of from about 0.1 to about 0.4 in an amount to provide at least 1000 ppm of calcium, (c) one or more magnesium-containing detergents having about 100 to about 1000 ppm of magnesium, based on the total weight of the lubricating oil composition, and (d) one or more zinc dialkyl dithiophosphate compounds derived from a primary alcohol.