The present invention relates to a method of processing a workpiece comprising contacting a tool and a workpiece to effect a change in the shape of the workpiece, and applying a metalworking fluid to a surface area where the tool and the workpiece are in contact, where the metalworking fluid contains a propoxylate of the formula R—O—(C.sub.3H.sub.6O).sub.n—H, where R is a branched C.sub.6 to C.sub.20 alkyl and n is from 3 to 30. The invention further relates to the metalworking fluid, and to a use of the propoxylate as additive in metalworking fluids.

The present invention provides a lubricating oil composition comprising: (A) a lubricant base oil including at least one type selected from mineral oil, PAO, and GTL (gas-to-liquid) base oils; (B) a compound having a structure obtained by independently subjecting propylene oxide to addition polymerization with an alcohol or a structure obtained by subjecting a combination of propylene oxide with ethylene oxide and/or butylene oxide to addition polymerization with an alcohol, and being configured so that polyalkylene glycol (PAG) with an oxygen/carbon weight ratio of 0.35 or more and less than 0.45 and/or one or both terminal hydroxyl groups in the polyalkylene glycol (PAG) are blocked; and (C) a fatty acid ester having an oxygen/carbon weight ratio of 0.05 to 0.35.

The present invention provides a lubricating oil composition comprising: (A) a lubricant base oil including at least one type selected from mineral oil, PAO, and GTL (gas-to-liquid) base oils; (B) a compound having a structure obtained by independently subjecting propylene oxide to addition polymerization with an alcohol or a structure obtained by subjecting a combination of propylene oxide with ethylene oxide and/or butylene oxide to addition polymerization with an alcohol, and being configured so that polyalkylene glycol (PAG) with an oxygen/carbon weight ratio of 0.35 or more and less than 0.45 and/or one or both terminal hydroxyl groups in the polyalkylene glycol (PAG) are blocked; and (C) a fatty acid ester having an oxygen/carbon weight ratio of 0.05 to 0.35.

A lubricating oil composition prepared by blending a base oil (A) containing a compound (A1) that is an ester or ether and has two or more aromatic rings, with a polyalkylene glycol (B) is provided. The lubricating oil composition has a high density (i.e., a high bulk modulus), a high viscosity index, and excellent shear stability.

A lubricating oil composition prepared by blending a base oil (A) containing a compound (A1) that is an ester or ether and has two or more aromatic rings, with a polyalkylene glycol (B) is provided. The lubricating oil composition has a high density (i.e., a high bulk modulus), a high viscosity index, and excellent shear stability.

The present invention relates to a polyether compound having a halogen atom content of 0.1000% by mass or less in terms of a polymer molecule thereof as measured by combustion ion chromatography and a weight average molecular weight (Mw) of 140,000 or more and 1,000,000 or less.

The present invention relates to a polyether compound having a halogen atom content of 0.1000% by mass or less in terms of a polymer molecule thereof as measured by combustion ion chromatography and a weight average molecular weight (Mw) of 140,000 or more and 1,000,000 or less.

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.

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.