The present invention provides a refrigerating machine oil comprising a base oil; a sulfide compound; and an orthophosphoric acid ester, wherein a content of the sulfide compound is 0.01 to 2.0% by mass and a content of the orthophosphoric acid ester is 0.1 to 5.0% by mass, based on a total amount of the refrigerating machine oil, and the refrigerating machine oil having a kinematic viscosity at 40? C. of 3 to 500 mm.sup.2/s.

Compounds having the formula (F-I) below are provided herein:

##STR00001##

wherein: R.sup.1 is a C.sub.1-C.sub.5000 alkyl group; R.sup.2 is (i) a C.sub.4-C.sub.30 linear alkyl group or (ii) a C.sub.4-C.sub.5000 branched alkyl having the formula (F-II) below:

##STR00002##

wherein R.sup.5 and R.sup.6 at each occurrence are each independently a hydrogen or a C.sub.1-C.sub.30 linear alkyl group and n is a positive integer, provided however, among all of R.sup.5 and R.sup.6, at least one is a C.sub.1-C.sub.30 linear alkyl group; and R.sup.7 is a hydrogen or a C.sub.1-C.sub.30 linear alkyl group; R.sup.3 is hydrogen or a C.sub.1-C.sub.5000 alkyl group; and R.sup.4 is a C.sub.1-C.sub.50 alkyl group or an aromatic group. Processes for preparing compounds of formula (F-I) as well as base stock and lubricant compositions containing compounds of formula (F-I) are also provided.

The disclosed technology relates to a lubricant composition for automotive or industrial gears, as well as axles and bearings, the automotive or industrial gear oil containing an oil of lubricating viscosity, an optional phosphate and/or thiophosphate compound, a particular sulfurized olefin, either a metal thiophosphate compound, such as zinc dialkyldithiophosphate, a thiadiazole functionalized dispersant, or a mixture thereof, and a hydroxyl/amine containing booster, as well as a method of improving automotive or industrial gear operating efficiency and temperature by lubricating such automotive or industrial gears with the automotive or industrial gear oil.

The lubricating oil composition for gas engine of the present invention contains (A) a base oil, (B1) an overbased calcium salicylate, (B2) an overbased sodium sulfonate, (C1) an amine-based antioxidant, and (C2) a phenol-based antioxidant, a total content of the amine-based antioxidant (C1) and the phenol-based antioxidant (C2) being 4 mass % or more on a basis of the whole amount of the composition.

Disclosed is a lubricating oil composition containing a base oil, a viscosity index improver, a molybdenum-based friction modifier, a boron-containing dispersant, and at least two extreme-pressure additives selected from a sulfur-based extreme-pressure additive, a phosphorous-based extreme-pressure additive and a sulfur/phosphorus-based extreme-pressure additive, or a sulfur/phosphorus-based extreme-pressure additive. The base oil is a synthetic oil having a kinematic viscosity at 100 C. of 3 mm.sup.2/s or more and 10 mm.sup.2/s or less, the viscosity index improver is a resin having a number average molecular weight (Mn) of 1,000 or more and 10,000 or less, the mass ratio of boron atoms (B) contained in the boron-containing dispersant to molybdenum atoms (Mo) contained in the molybdenum-based friction modifier, [(B)/(Mo)] is 1 or more and 5 or less, and the mass ratio of sulfur atoms (S) to phosphorus atoms (P) contained in the extreme-pressure additive(s), [(S)/(P)] is 10 or more and 20 or less.

The present invention provides a refrigerating machine oil comprising a base oil; a sulfide compound; and an orthophosphoric acid ester, wherein a content of the sulfide compound is 0.01 to 2.0% by mass and a content of the orthophosphoric acid ester is 0.1 to 5.0% by mass, based on a total amount of the refrigerating machine oil, and the refrigerating machine oil having a kinematic viscosity at 40? C. of 3 to 500 mm.sup.2/s.

A phosphate complex of a borate ester provides wear- and friction-reducing performance to an engine or driveline device. The complex may be a pyroborate-hydrocarbyl-substituted phosphate adduct. Boric acid may be reacted with a diol to form an ester, then reacting said ester with an ammonium salt of phosphoric acid or a hydrocarbyl-substituted phosphoric acid.

A lubricant composition has an increased oxidation induction time. The lubricant composition includes a base oil present in an amount of greater than 85 parts by weight per 100 parts by weight of the lubricant composition. The lubricant composition also includes an antioxidant component including particular first, second, and third antioxidants.

The refrigerator lubricating oil of the present invention contains: a base oil containing, as a major component, a polyol ester (A) of a fatty acid (a1) that is a fatty acid having a number of carbon atoms of from 3 to 18 and a polyol (a2) that is selected from neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, and dipentaerythritol; and a disulfide and/or trisulfide compound (B), and the disulfide and/or trisulfide compound (B) is blended in an amount of from 30 to 10,000 ppm by mass in terms of sulfur equivalent based on the total amount of the refrigerator lubricating oil.

Disclosed is a lubricating oil composition comprising an oil of lubricating viscosity and an oil soluble synergistic mixture of antioxidants, said mixture comprising: a) a hindered amine antioxidant according to formula (I)

##STR00001## wherein each R.sup.1 is independently selected from a substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; R.sup.2 is selected from the group consisting of a hydrogen atom or a, substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; each R.sup.3 is independently selected from the group consisting of a hydrogen atom or a, substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; each R.sup.4 is independently selected from the group consisting of a hydrogen atom or a, substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; n is an integer from 1 to 4; and m is an integer from 1 to 5; and b) a molybdenum succinimide complex.