The present invention provides, among other things, a process to produce a low molecular weight dispersant polymethacrylate polymer (LMWDPMA), and the LMWDPMA itself, along with the use of the LMWDPMA in a lubricating composition, as well as a method for lubricating an internal combustion engine as disclosed herein.

A composition for cleaning a combustion engine system. The composition comprises a hydrocarbon. The hydrocarbon comprises respective first and second hydrocarbons. The first hydrocarbon comprises a lubricant, wherein the lubricant has a flash point, measured according to ASTM D93, of less than 80 C. The second hydrocarbon comprises an aromatic hydrocarbon, wherein the aromatic hydrocarbon has a flash point, measured according to ASTM D93, of greater than 62 C. The composition further comprises an oxygen donor. The oxygen donor comprises respective first and second oxygen donors. The first oxygen donor comprises a hydroxyl group and has a flash point, measured according to ASTM D93, of from 45 C. to 95 C. The second oxygen donor comprises a carbonyl group or an ether group and has a flash point, measured according to ASTM D93, of from 50 C. to 120 C.

This invention relates to a lubricating oil composition, or concentrate therefor, comprising or resulting from the admixing of: (i) base oil, (ii) one or more styrenic block copolymers having a radial structure where one or more blocks derived from conjugated diene monomers are distal to the radial center and one more blocks derived from vinyl aromatic monomers that are proximal to the radial center, and (iii) optionally one or more dispersants and or detergents.

The disclosed technology relates to a lubricant composition for automotive gears, axles and bearings, the lubricant composition containing an oil of lubricating viscosity and a metal thiophosphate compound, such as zinc dialkyldithiophosphate, as well as a method of obtaining extreme pressure performance in automotive gears, axles and bearings at lower sulfur content than is typical, by lubricating such automotive gears, axles and bearings with a lubricant composition containing a metal thiophosphate compound, such as zinc dialkyldithiophosphate.

A lubricating oil composition may contain a base oil (A) and a dispersant-type viscosity index improver (B), in which the nitrogen atom content based on the solid content of the dispersant-type viscosity index improver (B) is 0.50 to 1.50% by mass, and the weight-average molecular weight (Mw) thereof is 100,000 or more, and the content in terms of the solid content based on the total amount of the composition of the dispersant-type viscosity index improver (B) is more than 0.05% by mass and less than 5.0% by mass. The lubricating oil composition may exert excellent wear resistance in a state contaminated with soot.

A lubricating oil composition, including a base oil (P) and a copolymer (X). The copolymer (X) contains the following structural units (a) to (c): structural unit (a): a structural unit derived from a monomer (A) having a (meth)acryloyl group and a linear or branched alkyl group having 6 to 24 carbon atoms, structural unit (b): a structural unit derived from a monomer (B) having a (meth)acryloyl group and a polar group, and structural unit (c): a structural unit derived from a monomer (C) having a polymerizable functional group and a cyclic structural group. The copolymer (X) has a mass-average molecular weight (Mw) of 5,000 to 50,000, a content of the copolymer (X) in terms of resin content is 0.10% by mass to 2.5% by mass based on the total amount of the lubricating oil composition, and the lubricating oil composition has a 100 C. kinematic viscosity of 8.2 mm.sup.2/s or less.

This disclosure describes low-ash lubricating composition achieving the same or better performance of higher ash compositions by including selected antiwear system with ashless phosphorus-containing antiwear compounds and select detergent systems matching TBN contributions to the antiwear systems.

A lubricating oil composition may include a base oil (A), succinimide (B) which has not been modified with boron, succinimide (C) modified with boron, a metallic detergent (D), and an antioxidant (E), wherein the ratio of the content of boron atoms derived from ingredient (C) to the content of nitrogen atoms derived from ingredients (B) and (C), B/N, is 0.30 or less by mass, the lubricating oil composition satisfying requirement (I) and/or requirement (II). Requirement (I): Ingredient (D) includes a metallic detergent (D1) having a base value less than 100 mgKOH/g. Requirement (II): Ingredient (E) includes an amine-based antioxidant (E1), the content of ingredient (E1) being 1.00 mass % or less.

Disclosed are solvency enhancer compositions, for example, as additives to lubricating oils and as formulated in lubricating oil compositions and associated methods of preparation and use thereof. The compositions and methods can dissolve at least one of oxidation products and other organic polar compounds, due to lubricant degradation, formed and suspended in oil compositions including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols. Further described are methods for dissolving organic deposits in an oil system including adding an effective amount of a solvency enhancer to the oil system, wherein the solvency enhancer includes Guerbet alcohols. Also provided are methods for preventing sludge and varnish formation in in-service oils including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols.

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.