An industrial oil composition contains a mineral or a synthetic oil as a base oil, and a neutral phosphite ester derivative represented by the following formula (B) and a 2,6-di-t-butylphenol derivative represented by the following formula (C) as antioxidants. In the formula (B), R.sup.b21 to R.sup.b24 each independently represent an aliphatic hydrocarbon group of 10 to 16 carbon atoms. In the formula (C), R.sup.c1 represents a straight-chain or a branched alkyl group of 1 to 12 carbon atoms. ##STR00001##

A lubricating oil composition contains a base oil and a rust inhibitor, in which the base oil has a gas chromatogram measured by gas chromatography satisfying the particular condition (), and the rust inhibitor is at least one selected from a first rust inhibitor, a second rust inhibitor, a third rust inhibitor, and a fourth rust inhibitor, and satisfies the particular condition ().

This invention relates to a lubricating oil composition, or concentrate therefor, comprising or resulting from the admixing of: (i) base oil, (ii) one or more styrenic block copolymers having a radial structure where one or more blocks derived from conjugated diene monomers are distal to the radial center and one more blocks derived from vinyl aromatic monomers that are proximal to the radial center, and (iii) optionally one or more dispersants and or detergents.

The present invention relates to new additive mixtures, processes for the production thereof and the use thereof for turbine oils.

A polyalkylene glycol-based compound of formula (1): ##STR00001##
may be one in which R.sup.1 is a monovalent hydrocarbon group having 1 to 32 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 42 ring carbon atoms, a monovalent acyl group having 2 to 32 carbon atoms, or a monovalent oxygen-containing hydrocarbon group having 2 to 32 carbon atoms; R.sup.2 is a monovalent hydrocarbon group having 1 to 32 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 42 ring carbon atoms, a monovalent acyl group having 2 to 32 carbon atoms, a monovalent oxygen-containing hydrocarbon group having 2 to 32 carbon atoms, or a hydrogen atom; R.sup.3 is a divalent hydrocarbon group having 4 carbon atoms; R.sup.4 is a divalent hydrocarbon group having 2 or 3 carbon atoms; m and n are respectively numbers between 1 and 40 and 0 and 20; and m/(m+n)0.5.

A dielectric fluid is provided comprising an oil and one or more compounds selected from the group consisting of phosphite compounds. It has been discovered that addition of one or more compounds selected from the group consisting of phosphite compounds to dielectric fluids comprising oil impart a stabilizing effect that reduces, inhibits or prevents formation of stray gases in the dielectric fluid during ordinary use.

A dielectric fluid is provided comprising a natural bio-sourced oil and one or more compounds selected from the group consisting of phosphite compounds. It has been discovered that addition of one or more compounds selected from the group consisting of phosphite compounds to dielectric fluids comprising oil impart a stabilizing effect that reduces, inhibits or prevents formation of stray gases in the dielectric fluid during ordinary use.

A composition is provided to comprise a non-aqueous medium and a 3,4-oxypyridinone compound of structure (I): ##STR00001##
with each A being oxygen and/or sulfur, and with a variety of substituents at R.sub.1-R.sub.5 to enable a solution or an at least semi-stable emulsion to be formed in the non-aqueous medium. Methods of use are included herein, which may be focused on situations where the composition can be used as a lubricant and/or coolant.

A lubricating oil composition may include a base oil (A), succinimide (B) which has not been modified with boron, succinimide (C) modified with boron, a metallic detergent (D), and an antioxidant (E), wherein the ratio of the content of boron atoms derived from ingredient (C) to the content of nitrogen atoms derived from ingredients (B) and (C), B/N, is 0.30 or less by mass, the lubricating oil composition satisfying requirement (I) and/or requirement (II). Requirement (I): Ingredient (D) includes a metallic detergent (D1) having a base value less than 100 mgKOH/g. Requirement (II): Ingredient (E) includes an amine-based antioxidant (E1), the content of ingredient (E1) being 1.00 mass % or less.

Disclosed are solvency enhancer compositions, for example, as additives to lubricating oils and as formulated in lubricating oil compositions and associated methods of preparation and use thereof. The compositions and methods can dissolve at least one of oxidation products and other organic polar compounds, due to lubricant degradation, formed and suspended in oil compositions including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols. Further described are methods for dissolving organic deposits in an oil system including adding an effective amount of a solvency enhancer to the oil system, wherein the solvency enhancer includes Guerbet alcohols. Also provided are methods for preventing sludge and varnish formation in in-service oils including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols.