Lubricant compositions, core-shell nanoparticles, and related methods are disclosed. In an exemplary embodiment, a lubricant composition includes a plurality of core-shell nanoparticles. The nanoparticles include a core, a first shell disposed on the core, and a second shell disposed on the first shell. The first shell is formed from a siliceous material and the second shell is formed from a hydrophobic material. The first and second shells form functional coatings that reduce wear and friction of parts lubricated with the lubricant composition.

Lubricant compositions, core-shell nanoparticles, and related methods are disclosed. In an exemplary embodiment, a lubricant composition includes a plurality of core-shell nanoparticles. The nanoparticles include a core, a first shell disposed on the core, and a second shell disposed on the first shell. The first shell is formed from a siliceous material and the second shell is formed from a hydrophobic material. The first and second shells form functional coatings that reduce wear and friction of parts lubricated with the lubricant composition.

The present invention provides a process for preparing a polymer, employing the steps of: (1) contacting a free radical initiator; a chain transfer agent containing a thiocarbonyl thio group and a free radical leaving group; and a radically polymerizable monomer, to form a polymer chain; and (2) contacting the polymer chain of step (1) with at least one of a polyvalent coupling agent, a polymerization inhibitor, a grafting acylating agent, an amine and an oil of lubricating viscosity. The invention further provides compositions and uses for the polymer.

The present invention provides a process for preparing a polymer, employing the steps of: (1) contacting a free radical initiator; a chain transfer agent containing a thiocarbonyl thio group and a free radical leaving group; and a radically polymerizable monomer, to form a polymer chain; and (2) contacting the polymer chain of step (1) with at least one of a polyvalent coupling agent, a polymerization inhibitor, a grafting acylating agent, an amine and an oil of lubricating viscosity. The invention further provides compositions and uses for the polymer.

A lubricating oil composition may include a base oil (A), an olefin copolymer (B), and a poly(alkyl(meth)acrylate) (C), in which a weight average molecular weight of the olefin copolymer (B) is 10,000 to 80,000, a content of the olefin copolymer (B) is 0.01% to 0.23% by mass based on the total amount of the lubricating oil composition, and a content of the poly(alkyl(meth)acrylate) (C) is 0.02% to 0.40% by mass based on the total amount of the lubricating oil composition.

A lubricating oil composition may include a base oil (A), an olefin copolymer (B), and a poly(alkyl(meth)acrylate) (C), in which a weight average molecular weight of the olefin copolymer (B) is 10,000 to 80,000, a content of the olefin copolymer (B) is 0.01% to 0.23% by mass based on the total amount of the lubricating oil composition, and a content of the poly(alkyl(meth)acrylate) (C) is 0.02% to 0.40% by mass based on the total amount of the lubricating oil composition.

A lubricating oil composition for automotive transmissions is disclosed. It offers an automotive transmission (especially a fuel-saving type) which satisfies all requirements as regards the properties of resistance to churning, maintenance of the oil film and low-temperature viscosity. It comprises a GTL low viscosity base oil and a Group 1 high viscosity base oil.

A lubricating oil composition for automotive transmissions is disclosed. It offers an automotive transmission (especially a fuel-saving type) which satisfies all requirements as regards the properties of resistance to churning, maintenance of the oil film and low-temperature viscosity. It comprises a GTL low viscosity base oil and a Group 1 high viscosity base oil.

Provided is a lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.7 to about 3.2 mPa s and a low temperature cold cranking viscosity of less than 7,000 mPa s at −20° C., comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. of from 3.5 mm.sup.2/s to 20 mm.sup.2/s and a viscosity index of greater than 120 with a sulfur content of less than 0.03 wt. %, are classified into the API group III, IV, or V base stock category, and have an aromatics content (C.sub.A) of less than 5%; (b) an organomolybdenum compound; (c) a dispersed hydrated alkali metal borate compound; (e) one or more dispersants; (f) one or more calcium-based metal detergents; and (g) optionally, one or more magnesium-based metal detergents. Also provided is a method for improving wear, high temperature detergency, and thermal stability in an engine comprising operating said engine with said lubricating oil composition.

Polyalkyl(meth)acrylates contain specified amounts of long-chain alkyl (meth)acrylates and functional monomers. Lubricant compositions can contain such polyalkyl(meth)acrylates, and the polyalkyl(meth)acrylates can be used as viscosity index (VI) improvers with good fuel economy as well as soot-dispersant function. The polyalkyl(meth)acrylates can provide equal or even unproved deposits in lubricant compositions, especially in engine oil (EO) compositions.