A lubricating composition includes at least one base oil, at least one dispersant and at least one phosphite polymer having formula (I) wherein each of the R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be independently selected from the C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers and Y—OH groups; Y is selected from among the C2-C40 alkylene, C2-C40 alkyl lactone —R.sup.7—N(R.sup.8)—R.sup.9— groups, R.sup.7, R.sup.8 and R.sup.9 are independently selected from among hydrogen, C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers; m is an integer from 2 to 100; and n is an integer from 1 to 1000.

A lubricating composition contains at least one base oil and at least one phosphite polymer having the formula (I) wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be independently selected from the C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers and Y—OH groups; Y is selected from among the C2-C40 alkylene, C2-C40 alkyl lactone groups; —R.sup.7—(N(R.sup.8)—R.sup.9—, wherein R.sup.7, R.sup.8 and R.sup.9 are independently selected from among hydrogen, C1-C20 alkyl, C3-C22 alkenyl, C6-C40 cycloalkyl, C7-C40 cycloalkenyl, C1-20 methoxy alkyl glycol ethers; m is an integer from 2 to 100; and n is an integer from 1 to 1000.

The present invention relates to provision of an extreme pressure agent-containing grease composition using, as a thickener, a urea-based thickener, the grease composition being excellent in both torque transmitting efficiency and leakage prevention performance and also excellent in wear resistance and load resistance. The grease composition contains a base oil (A), a urea-based thickener (B), and an extreme pressure agent (C), wherein particles containing the urea-based thickener (B) in the grease composition satisfies the following requirement (I): Requirement (I): an arithmetic average particle diameter of the particles on an area basis as measured by the laser diffraction/scattering method is 2.0 μm or less, and the extreme pressure agent (C) is at least one selected from an organic metal-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and a sulfur-phosphorus-based extreme pressure agent.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.

A refrigerating machine oil containing a hydrocarbon base oil having a 90% distillation temperature of 270° C. or lower.

This invention provides a water-glycol hydraulic fluid comprises from 0.2 to 0.6% by mass of a dimer acid as a fatty acid lubricant, and more than 0.10% by mass and 0.20% by mass or less of a phosphoric acid ester of Formula (1), wherein the sum of the dimer acid and the phosphoric acid ester is more than 0.35% by mass wherein R.sub.1 and R.sub.2 may be the same or different, each representing a hydrogen atom or a hydrocarbon group having from 1 to 30 carbon atoms, R.sub.3 represents a hydrocarbon group having from 1 to 20 carbon atoms, R.sub.4 represents a hydrogen atom or a hydrocarbon group having from 1 to 30 carbon atoms, and X.sub.1, X.sub.2, X.sub.3 and X.sub.4 may be the same or different, each representing an oxygen atom or a sulfur atom.

##STR00001##

The disclosed technology relates to a lubricant composition for automotive gears, axles and bearings, the lubricant composition containing an oil of lubricating viscosity and an oil-soluble titanium compound in place of boron compounds, as well as a method of obtaining thermal stability performance in automotive gears, axles and bearings without the boron content that is typical, by lubricating such automotive gears, axles and bearings with a lubricant composition containing an oil-soluble titanium compound and an amine-containing phosphorus rainwear agent.

One aspect of the present invention is a refrigerating machine oil containing: a base oil containing an ester of an alcohol and a fatty acid; a compound represented by the following formula (1): ##STR00001##
wherein R.sup.1 and R.sup.2 each independently represent a monovalent hydrocarbon group, R.sup.3 represents a divalent hydrocarbon group, and R.sup.4 represents hydrogen atom or a monovalent hydrocarbon group, and the refrigerating machine oil having a kinematic viscosity at 40° C. of 10 mm.sup.2/s or less.

One aspect of the present invention is a refrigerating machine oil comprising a base oil, a dithiophosphoric acid ester, and a phosphonate ester.

One aspect of the present invention is a refrigerating machine oil comprising a base oil, a dithiophosphoric acid ester, and an amine salt of an acidic phosphoric acid ester.