To provide a lubricating oil composition achieving both of high traction coefficient and excellent low temperature fluidity at a higher level and having a high flash point, which contains a naphthene-based synthetic oil (a) having a flash point of 140° C. or higher, and an ester (b) having 5 to 32 carbon atoms and having a branched chain, wherein the content of the naphthene-based synthetic oil (a) based on the total amount of the composition is 35% by mass or more and less than 80% by mass, a method for producing the lubricating oil composition, and a continuously variable transmission using the lubricating oil composition.

A booster additive concentrate may advantageously contain: (a) an anti-wear mixture of two or more phosphite/phosphate compounds and one or more ether/thioether compounds; (b) an ashless dispersant; (c) a calcium-containing detergent, such as an overbased calcium phenate; (d) ≥2 friction modifiers, at least one of which comprises a polyalkylene polyamine succinimide derivative; (e) optionally a corrosion inhibitor; and (f) a lubricating oil basestock. Based on these additive components, the booster additive concentrate may exhibit specific contents of B/Ca/P and may contain minimal or substantially no additional antioxidants. Lubricant compositions can be made from the booster additive concentrates and a fresh/used lubricant oil composition “diluent,” which can rejuvenate the diluent. Such lubricant compositions can have advantageous anti-shudder durability (ASD) lifetimes and other frictional properties. In particular, such concentrates/compositions can offer superior lubrication when used in vehicles with continuously variable transmissions (CVTs).

A composition obtained by reacting an O,O′-dialkyldithiophosphoric acid with a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate, and reacting the product thereof with a dialkylphosphite provides good antiwear protection.

A grease composition for constant velocity joints can have excellent wear resistance, and may include a base oil (A) and a urea-based thickening agent (B) of formula (B1): R.sup.1—NHCONH—R.sup.3—NHCONH—R.sup.2 (B1), wherein R.sup.1 and R.sup.2 are independently a monovalent C6 to C24 hydrocarbon group, R.sup.1 and R.sup.2 optionally differing; and R.sup.3 is a divalent C6 to C18 aromatic hydrocarbon group, the monovalent hydrocarbon group containing an alicyclic hydrocarbon group and a hydrocarbon chain, and optionally containing an aromatic hydrocarbon group, wherein, in R.sup.1 and R.sup.2 of formula (B1), if the content of the alicyclic hydrocarbon group is X molar equivalent, the content of the hydrocarbon chain is Y molar equivalent, and the content of the aromatic hydrocarbon group is Z molar equivalent, (a) and (b) are satisfied: (a): a value of {(X+Y)/(X+Y+Z)}×100 is 90 or more; (b): an X/Y ratio is 10/90 to 75/25.

Disclosed is a lubricating oil composition capable of inhibiting vibrations or noises generated between a pulley and a chain or between a pulley and a belt in a CVT or the like, while increasing an intermetallic friction coefficient, the composition containing a base oil, an alkaline earth metal-based detergent (A), a phosphite ester (B1), a phosphate ester amine salt (B2), an acidic phosphate ester (B3), an aliphatic monoamine (C1), and an aromatic monoamine (C2).

There is disclosed an antifoam component which includes at least one poly(acrylate) copolymer for use in a diesel fuel. Poly(acrylate) polymers prepared by polymerizing a (meth)acrylate monomer comprising C.sub.1 to C.sub.30 alkyl esters of (meth)acrylic acid (“multifunctional monomer”) are also disclosed. Other poly(acrylate) polymers prepared by polymerizing (i) a (meth)acrylate monomer comprising C.sub.1 to C.sub.4 alkyl esters of (meth)acrylic acid (“solubility monomer”); (ii) a (meth)acrylate monomer comprising C.sub.5 to C.sub.12 alkyl esters of (meth)acrylic acid (“surface tension monomer”); and (iii) optionally at least one additional monomer comprising a solubility monomer, a surface tension monomer, a monomer comprising C.sub.1 to C.sub.30 alkyl esters of (meth)acrylic acid (“multifunctional monomer”), or combinations thereof are also disclosed.

The invention provides a lubricating oil composition for automatic transmissions is made such that it comprises proportionately as its main constituents: 60 to 98 mass % as low viscosity base oils being base oils belonging to Groups 2 to 4 of the API (American Petroleum Institute) base oil categories wherein the kinematic viscosity at 100° C. is 2 to 5 mm.sup.2/s (Fischer-Tropsch synthetic oil comprising at least 45 to 80 mass %); 1 to 20 mass % as high-viscosity base oils being metallocene/poly-α-olefins with a kinematic viscosity at 100° C. of 100 to 600 mm.sup.2/s; and 1 to 20 mass % being a polymethacrylate with a weight-average molecular weight of 10,000 to 50,000. The viscosity index of this composition is not less than 190, the Brookfield viscosity at −40° C. is not more than 5000 mPa.Math.s, the 100° C. kinematic viscosity is 5 to 7 mm.sup.2/s, and the rate of reduction of the 100° C. kinematic viscosity after a KRL shear stability test (60° C., 20 hr) is not more than 3%.

Provided are: a lubricating oil composition containing a mineral oil (A) having a kinematic viscosity at 40° C. of 5 to 15 mm.sup.2/s and a flash point of 180° C. or higher, a synthetic oil (B) having a kinematic viscosity at 40° C. of 5 to 15 mm.sup.2/s and a flash point of 190° C. or higher, an amide compound (C) and a polyol ester compound (D), which has a low viscosity and fuel saving performance, which can be used in high-temperature environments, and which has excellent gear anti-seizing property and anti-shudder performance; and a lubrication method and a transmission using the lubricating oil composition.

The disclosed technology relates to the inhibition of corrosion on electrically conductive componentry subjected to a lubricant composition, but that is not submersed in the lubricant composition, or in other words, vapor phase corrosion inhibition. The technology more particularly relates to the use of azole compounds capable of inhibiting corrosion of the electrically conductive componentry in the vapor space above a lubricant composition, and often in the liquid phase of the lubricant composition as well.

The present disclosure relates to a continuously variable transmission oil composition containing a base oil containing a metallocene polyalpha olefin (mPAO) polymerized with a metallocene catalyst, a viscosity controlling agent containing Polybutadiene hydrogen phosphate Comb Polymethacrylate, and a clean dispersant, and contains mPAO and PHP Comb PMA, which have not been used previously, at a specific ratio to maximize the reduction in low-temperature viscosity while effectively forming an oil film, thereby enhancing fuel efficiency, and at the same time, enhancing durability of a transmission by increasing viscosity.