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.

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.

A lubricating oil composition may include a base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and a metal salt (E) including a metal sulfonate, a metal salicylate, and/or a metal phenate, in which a content of the acidic phosphorus compound (C) in terms of phosphorus atoms is 10 to 180 ppm by mass based on the total amount of the lubricating oil composition, a content of the sulfur compound (D) in terms of sulfur atoms is 10 to 1000 ppm by mass based on the total amount of the lubricating oil composition, and a content of the metal salt (E) in terms of metal atoms is 5 to 180 ppm by mass based on the total amount of the lubricating oil composition.

A lubricating oil composition may include a base oil (A), a neutral phosphorus compound (B), an acidic phosphorus compound (C), a sulfur compound (D) and a metal salt (E) including a metal sulfonate, a metal salicylate, and/or a metal phenate, in which a content of the acidic phosphorus compound (C) in terms of phosphorus atoms is 10 to 180 ppm by mass based on the total amount of the lubricating oil composition, a content of the sulfur compound (D) in terms of sulfur atoms is 10 to 1000 ppm by mass based on the total amount of the lubricating oil composition, and a content of the metal salt (E) in terms of metal atoms is 5 to 180 ppm by mass based on the total amount of the lubricating oil composition.

A lubricating and cooling fluid for an electric motor system including a lubricating base oil, at least one sulfurized component, a dispersant system comprising at least two dispersants, and a friction modifier system comprising at least two friction modifiers. The lubricating and cooling fluid provides good wear and friction performance as well as good copper corrosion and electrical conductivity for use in electric motor system.

A lubricating and cooling fluid for an electric motor system including a lubricating base oil, at least one sulfurized component, a dispersant system comprising at least two dispersants, and a friction modifier system comprising at least two friction modifiers. The lubricating and cooling fluid provides good wear and friction performance as well as good copper corrosion and electrical conductivity for use in electric motor system.

The present invention provides a lubricating oil additive, including: a molybdenum compound (A) represented by the following general formula (1); and a sulfur-based composition (B) containing a sulfur-based compound (b-1) represented by the following general formula (2) and at least one kind of sulfur-based compound (b-2) represented by the following general formula (3) or (4), and a lubricating oil composition containing the additive. In the formula (1), R.sup.1 to R.sup.4 each represent alkyl groups having 6 to 18 carbon atoms, the groups being identical to or different from each other, and X.sup.1 to X.sup.4 each independently represent an oxygen atom or a sulfur atom. In the formula (2), R.sup.5 and R.sup.6 each represent alkyl groups having 3 to 24 carbon atoms, the groups being identical to or different from each other, and “a” and “b” each represent a number from 1 to 5. In the formulae (3) and (4), R.sup.7 to R.sup.10 each represent alkylene groups having 1 to 28 carbon atoms, the groups being identical to or different from each other, R.sup.11 and R.sup.12 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and “c” and “d” each independently represent a number from 1 to 8, provided that at least one of R.sup.11 or R.sup.12 represents an alkyl group having 1 to 3 carbon atoms.

##STR00001##

The present invention provides a lubricating oil additive, including: a molybdenum compound (A) represented by the following general formula (1); and a sulfur-based composition (B) containing a sulfur-based compound (b-1) represented by the following general formula (2) and at least one kind of sulfur-based compound (b-2) represented by the following general formula (3) or (4), and a lubricating oil composition containing the additive. In the formula (1), R.sup.1 to R.sup.4 each represent alkyl groups having 6 to 18 carbon atoms, the groups being identical to or different from each other, and X.sup.1 to X.sup.4 each independently represent an oxygen atom or a sulfur atom. In the formula (2), R.sup.5 and R.sup.6 each represent alkyl groups having 3 to 24 carbon atoms, the groups being identical to or different from each other, and “a” and “b” each represent a number from 1 to 5. In the formulae (3) and (4), R.sup.7 to R.sup.10 each represent alkylene groups having 1 to 28 carbon atoms, the groups being identical to or different from each other, R.sup.11 and R.sup.12 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and “c” and “d” each independently represent a number from 1 to 8, provided that at least one of R.sup.11 or R.sup.12 represents an alkyl group having 1 to 3 carbon atoms.

##STR00001##

A gear lubricant composition includes at least 97% by weight, based on the total weight of the lubricant composition, of at least one hydrocarbon-based oil that includes a weight content of isoparaffins ranging from 90 to 0%, a weight content of normal paraffins ranging from 0 to 10% and a carbon content of biological origin greater than or equal to 90% relative to the total weight of the oil, at least 0.01% by weight, based on the total weight of the lubricant composition, of at least one additive selected among the anti-wear additives, extreme pressure additives, anti-corrosion additives, additives having metal-deactivating properties, anti-foam additives, anti-oxidant additives selected among the phenolic anti-oxidants, and the mixtures thereof.

A gear lubricant composition includes at least 97% by weight, based on the total weight of the lubricant composition, of at least one hydrocarbon-based oil that includes a weight content of isoparaffins ranging from 90 to 0%, a weight content of normal paraffins ranging from 0 to 10% and a carbon content of biological origin greater than or equal to 90% relative to the total weight of the oil, at least 0.01% by weight, based on the total weight of the lubricant composition, of at least one additive selected among the anti-wear additives, extreme pressure additives, anti-corrosion additives, additives having metal-deactivating properties, anti-foam additives, anti-oxidant additives selected among the phenolic anti-oxidants, and the mixtures thereof.