A lubricant composition includes a base oil, a phenothiazine-based polymerization inhibitor, and a polymerization inhibitory accelerator including a hindered phenol-based compound and a hydroquinone-based compound. A self-polymerization in a polymerizing process is suppressed by an interaction between the polymerization inhibitor and the polymerization inhibitory accelerator. A method of preparing a copolymer using the lubricant composition is also provided.

A lubricant composition includes a base oil, a phenothiazine-based polymerization inhibitor, and a polymerization inhibitory accelerator including a hindered phenol-based compound and a hydroquinone-based compound. A self-polymerization in a polymerizing process is suppressed by an interaction between the polymerization inhibitor and the polymerization inhibitory accelerator. A method of preparing a copolymer using the lubricant composition is also provided.

The disclosed technology relates to an automotive gear oil, which may be used, for example, in heavy duty manual transmissions and axles, and includes an oil of lubricating viscosity, 1 wt % or less of a dispersant, and at least one boron containing compound.

The disclosed technology relates to an automotive gear oil, which may be used, for example, in heavy duty manual transmissions and axles, and includes an oil of lubricating viscosity, 1 wt % or less of a dispersant, and at least one boron containing compound.

A lubricating oil composition including: a lubricating base oil; (A) a poly(meth)acrylate having a weight average molecular weight of no more than 50,000, in an amount of 2 to 10 mass %; (B) a phosphite ester of the general formula (1) in an amount of 0.01 to 0.06 mass % in terms of P; (C) a thiadiazole compound in an amount of 0.01 to 0.2 mass %; and (D) a Ca salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of Ca, wherein the lubricating oil composition has a kinematic viscosity at 40 C. of 4.0 to 20.0 mm.sup.2/s, and a kinematic viscosity at 100 C. of 1.8 to 5.2 mm.sup.2/s; and has a ratio [S]/[P] of 2.2 to 4.0, wherein the [S] represents a sulfur content, and the [P] represents a phosphorus content:

##STR00001##

wherein R.sup.1 and R.sup.2 are each independently a group having 5 to 20 carbons represented by the general formula (2); and

##STR00002##

wherein R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C2-17 linear chain hydrocarbon group.

A lubricating oil composition including: a lubricating base oil; (A) a poly(meth)acrylate having a weight average molecular weight of no more than 50,000, in an amount of 2 to 10 mass %; (B) a phosphite ester of the general formula (1) in an amount of 0.01 to 0.06 mass % in terms of P; (C) a thiadiazole compound in an amount of 0.01 to 0.2 mass %; and (D) a Ca salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of Ca, wherein the lubricating oil composition has a kinematic viscosity at 40 C. of 4.0 to 20.0 mm.sup.2/s, and a kinematic viscosity at 100 C. of 1.8 to 5.2 mm.sup.2/s; and has a ratio [S]/[P] of 2.2 to 4.0, wherein the [S] represents a sulfur content, and the [P] represents a phosphorus content:

##STR00001##

wherein R.sup.1 and R.sup.2 are each independently a group having 5 to 20 carbons represented by the general formula (2); and

##STR00002##

wherein R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C2-17 linear chain hydrocarbon group.

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein x is 0 or 1 and R.sup.1 is a hydrocarbyl group containing about 4 to about 18 carbon atoms, which composition is effective at swelling seals. ##STR00001##

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein x is 0 or 1 and R.sup.1 is a hydrocarbyl group containing about 4 to about 18 carbon atoms, which composition is effective at swelling seals. ##STR00001##

The present disclosure describes a lubricating composition including a) a major part of a base oil of lubricating viscosity wherein the base oil is selected from API Group I, II, III, IV, V, or mixtures thereof, b) a total of 0.001 to 0.536 wt. %, based on the total lubricating composition, of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) according to Formula (I), or a tautomer or salt thereof, below ##STR00001## wherein R is methyl or C.sub.2 to C.sub.4 alkyl, wherein the total lubricating composition has a sulfur content of up to 2,500 ppm (wt.), c) less than 0.1 wt % phosphite. The disclosure further describes the use of the lubricating composition for lubricating a driveline, a transmission including a manual or automated transmission, a gear, an automated gear, or an axle, and for enhanced FZG test performance. The disclosure further relates to a method for preparing the lubricating composition.

The present disclosure describes a lubricating composition including a) a major part of a base oil of lubricating viscosity wherein the base oil is selected from API Group I, II, III, IV, V, or mixtures thereof, b) a total of 0.001 to 0.536 wt. %, based on the total lubricating composition, of one or more monohydrocarbyl-substituted dimercaptothiadiazole derivative(s) according to Formula (I), or a tautomer or salt thereof, below ##STR00001## wherein R is methyl or C.sub.2 to C.sub.4 alkyl, wherein the total lubricating composition has a sulfur content of up to 2,500 ppm (wt.), c) less than 0.1 wt % phosphite. The disclosure further describes the use of the lubricating composition for lubricating a driveline, a transmission including a manual or automated transmission, a gear, an automated gear, or an axle, and for enhanced FZG test performance. The disclosure further relates to a method for preparing the lubricating composition.