Disclosed is a method of treating a used hydrocarbon lubricant of ISO Viscosity Grade 46 or higher comprising oxidation products that adversely affect lubricant performance. The hydrocarbon lubricant has a Group II hydrocarbon oil or Group III hydrocarbon oil, optionally one or more lubricant additives, and an amount of varnish. The hydrocarbon lubricant is free of zinc-containing additives. The method comprises adding to the used hydrocarbon lubricant from about 2 percent by weight to about 20 percent by weight of a polyhydroxy polypropylene oxide homopolymer that has a hydroxyl number of from about 12 mg KOH/g to about 58 mg KOH/g as measured according to ASTM D4274.

Disclosed is a method of treating a used hydrocarbon lubricant of ISO Viscosity Grade 46 or higher comprising oxidation products that adversely affect lubricant performance. The hydrocarbon lubricant has a Group II hydrocarbon oil or Group III hydrocarbon oil, optionally one or more lubricant additives, and an amount of varnish. The hydrocarbon lubricant is free of zinc-containing additives. The method comprises adding to the used hydrocarbon lubricant from about 2 percent by weight to about 20 percent by weight of a polyhydroxy polypropylene oxide homopolymer that has a hydroxyl number of from about 12 mg KOH/g to about 58 mg KOH/g as measured according to ASTM D4274.

A blend for lubricating a surface includes a lubricant and a polyepoxide co(ter)polymer additive mixed with the lubricant. The polyepoxide co(ter)polymer additive includes a first block having monomer M.sub.1 and a second block having monomer M.sub.2. The first monomer M.sub.1 includes hexene oxide, HO, or octene oxide, OO, and the second monomer M.sub.2 includes propylene oxide, PO.

The present invention relates to new ether carboxylic acids as high temperature stable rheology modifier, viscosifier, lubricant or emulsifier additives in oilfield and industrial applications. In particular, the invention relates to an ether carboxylic acid or a derivative thereof obtainable by reacting a branched polyol alkoxylate with a halogen carboxylic acid or a halogen carboxylic acid derivative. Further aspects of the invention relate to a lubricant composition comprising an ether carboxylic acid of the invention and the use of said ether carboxylic acid.

The present invention relates to new ether carboxylic acids as high temperature stable rheology modifier, viscosifier, lubricant or emulsifier additives in oilfield and industrial applications. In particular, the invention relates to an ether carboxylic acid or a derivative thereof obtainable by reacting a branched polyol alkoxylate with a halogen carboxylic acid or a halogen carboxylic acid derivative. Further aspects of the invention relate to a lubricant composition comprising an ether carboxylic acid of the invention and the use of said ether carboxylic acid.

An ashless lubricating oil having a lubricating oil base stock as a major component, and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components. The lubricating oil base stock is a monoester obtained by a) reacting one Guerbet alcohol of 8 to 20 carbon atoms with a Guerbet acid, a linear or branched acid of 6 to 20 carbon atoms or b) reacting one linear or branched alcohol with at least 6 to 20 carbon atoms with a Guerbet acid of 8 to 20 carbon atoms. The lubricating oil base stock is present in an amount from 30 to 99.8 wt. % of the oil. A method for improving oxidative stability and high temperature stability of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using the ashless lubricating oil.

An ashless lubricating oil having a lubricating oil base stock as a major component, and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components. The lubricating oil base stock is a monoester obtained by a) reacting one Guerbet alcohol of 8 to 20 carbon atoms with a Guerbet acid, a linear or branched acid of 6 to 20 carbon atoms or b) reacting one linear or branched alcohol with at least 6 to 20 carbon atoms with a Guerbet acid of 8 to 20 carbon atoms. The lubricating oil base stock is present in an amount from 30 to 99.8 wt. % of the oil. A method for improving oxidative stability and high temperature stability of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using the ashless lubricating oil.

An ashless lubricating oil having a lubricating oil base stock as a major component, and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components. The lubricating oil base stock is a branched polyol ester. The lubricating oil base stock is present in an amount from about 30 to about 99.8 mass percent, based on the total mass of the ashless lubricating oil. A method for improving oxidative stability and high temperature stability of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using the ashless lubricating oil. The ashless lubricating oil is useful as a passenger vehicle engine oil (PVEO).

An ashless lubricating oil having a lubricating oil base stock as a major component, and a mixture of (i) at least one ashless antiwear additive, (ii) at least one ashless detergent, and (iii) at least one aminic antioxidant, as minor components. The lubricating oil base stock is a branched polyol ester. The lubricating oil base stock is present in an amount from about 30 to about 99.8 mass percent, based on the total mass of the ashless lubricating oil. A method for improving oxidative stability and high temperature stability of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using the ashless lubricating oil. The ashless lubricating oil is useful as a passenger vehicle engine oil (PVEO).

Disclosed is a method of treating a used hydrocarbon lubricant of ISO Viscosity Grade 46 or higher comprising oxidation products that adversely affect lubricant performance. The hydrocarbon lubricant has a Group II hydrocarbon oil or Group III hydrocarbon oil, optionally one or more lubricant additives, and an amount of varnish. The hydrocarbon lubricant is free of zinc-containing additives. The method comprises adding to the used hydrocarbon lubricant from about 2 percent by weight to about 20 percent by weight of a polyhydroxy polypropylene oxide homopolymer that has a hydroxyl number of from about 12 mg KOH/g to about 58 mg KOH/g as measured according to ASTM D4274.