A lubricating oil composition including: a lubricant base oil; (A) a calcium salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of calcium on the basis of the total mass of the composition; and (B) a phosphite ester compound represented by the following general formula (1) in an amount of 0.01 to 0.06 mass % in terms of phosphorus on the basis of the total mass of the composition:

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wherein in the general formula (1), R.sup.1 and R.sup.2 are each independently a C5-20 group represented by the following general formula (2):

##STR00002##

wherein in the general formula (2), R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C3-17 linear chain hydrocarbon group, and X.sup.1 is an oxygen atom or a sulfur atom.

Provided is a lubricating oil composition for air compressors containing a polyalkylene glycol-containing base oil (A) and a rust-preventive agent (B), wherein the content of the polyalkylene glycol is 65.0% by mass or more based on the total amount of the composition. The lubricating oil composition is excellent in oxidation stability and also in rust prevention and storage stability. Also provided are an air compressor lubricating method and an air compressor using the lubricating oil composition.

Provided is a lubricating oil composition for air compressors containing a polyalkylene glycol-containing base oil (A) and a rust-preventive agent (B), wherein the content of the polyalkylene glycol is 65.0% by mass or more based on the total amount of the composition. The lubricating oil composition is excellent in oxidation stability and also in rust prevention and storage stability. Also provided are an air compressor lubricating method and an air compressor using the lubricating oil composition.

[Problem] To provide an aqueous coating agent composition (in particular, an aqueous coating composition for lubricating films that contains a solid lubricant) which as a whole is excellent in terms of flowability, applicability, and storage stability and which is capable of forming satisfactory and smooth coating films effective in stick-slip inhibition. [Solution] The problem can be solved with an aqueous coating agent composition which comprises (A) a curable resin in an aqueous emulsion form, (B) a surfactant, (C) solid particles, (D) one or more nitrogenous heterocyclic compounds, (E) a film-forming silicone in an aqueous emulsion form, and (F) water. In particular, it is preferable that the (C) component comprise a solid lubricant. In view of the environmental regulations, it is especially preferable that the (D) component be 1,3-dimethyl-2-imidazolidinone.

Provided is a lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.7 to about 3.2 mPa s and a low temperature cold cranking viscosity of less than 7,000 mPa s at −20° C., comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. of from 3.5 mm.sup.2/s to 20 mm.sup.2/s and a viscosity index of greater than 120 with a sulfur content of less than 0.03 wt. %, are classified into the API group III, IV, or V base stock category, and have an aromatics content (C.sub.A) of less than 5%; (b) an organomolybdenum compound; (c) a dispersed hydrated alkali metal borate compound; (e) one or more dispersants; (f) one or more calcium-based metal detergents; and (g) optionally, one or more magnesium-based metal detergents. Also provided is a method for improving wear, high temperature detergency, and thermal stability in an engine comprising operating said engine with said lubricating oil composition.

A lubricating oil composition for internal combustion engines containing a base oil (A), a metal-based detergent (B) containing a calcium-based detergent (B1), a zinc dialkyldithiophosphate (C), and a molybdenum-containing compound (D), wherein a calcium atom-equivalent content of the calcium-based detergent (B1) is more than 100 ppm by mass and 600 ppm by mass or less, based on a total amount of the composition, a magnesium atom-equivalent content of a magnesium-based detergent (B2) is less than 200 ppm by mass, based on the total amount of the composition, a sodium atom-equivalent content of a sodium-based detergent (B3) is less than 200 ppm by mass, based on the total amount of the composition, a content ratio of phosphorus derived from the zinc dialkyldithiophosphate (C) to calcium derived from the calcium-based detergent (B1) [P/Ca] is 0.25 or more by mass, and a sulfated ash content is 0.7% by mass or less; and a method for producing the composition.

A lubricating oil composition including: a lubricating base oil; (A) a first defoaming agent, the first defoaming agent being (A1) a first polymer, or (A2) a second polymer, or any combination thereof; and (B) a second defoaming agent, the second defoaming agent being a silicone defoaming agent, the (A1) first polymer including: a first polymer chain including a polysiloxane structure, the polysiloxane structure having a polymerization degree of 5 to 2000 and being represented by the following general formula (1); and a second polymer chain bonded with the first polymer chain, the second polymer chain including a repeating unit represented by the following general formula (2), the (A2) second polymer being a copolymer of a first monomer component and a second monomer component, the first monomer component represented by the general formula (7) or (8), the second monomer component represented by the general formula (9).

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The disclosure relates to a biobased metal-working fluid (MWF) composition and method for making same, and more particularly metal-working fluid with biobased lubricants with improved emulsion stability. At least 50 wt. % of the base oil component in the MWF concentrate is a plant-derived liquid decarboxylated rosin acid oil (“DCR”). The DCR comprises 50 to 100 wt. % of tricyclic compounds having 18-20 carbon atoms, one or more C═C groups, and m/z (mass/charge) value of 220-280; an oxygen content of <5%; a density of 0.9 to 1.0 g/cm.sup.3 at 20° C.; and an acid value of <10 mg KOH/g. The resulting MWF is characterized as having comparable if not better performance compared to a MWF containing only mineral oil (e.g., Group I or Group II).

The disclosure relates to a biobased metal-working fluid (MWF) composition and method for making same, and more particularly metal-working fluid with biobased lubricants with improved emulsion stability. At least 50 wt. % of the base oil component in the MWF concentrate is a plant-derived liquid decarboxylated rosin acid oil (“DCR”). The DCR comprises 50 to 100 wt. % of tricyclic compounds having 18-20 carbon atoms, one or more C═C groups, and m/z (mass/charge) value of 220-280; an oxygen content of <5%; a density of 0.9 to 1.0 g/cm.sup.3 at 20° C.; and an acid value of <10 mg KOH/g. The resulting MWF is characterized as having comparable if not better performance compared to a MWF containing only mineral oil (e.g., Group I or Group II).

The invention provides a lubricating composition comprising a low viscosity base oil and a synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate polymer, and a metal-free anti-wear agent. The invention also provides a method of lubricating an internal combustion engine using such a lubricating composition.