Provided is a lubricating oil composition for air compressors containing a polyalkylene glycol-containing base oil (A) and a rust-preventive agent (B), wherein the content of the polyalkylene glycol is 65.0% by mass or more based on the total amount of the composition. The lubricating oil composition is excellent in oxidation stability and also in rust prevention and storage stability. Also provided are an air compressor lubricating method and an air compressor using the lubricating oil composition.

A lubricant composition comprising an oil of lubricating viscosity and 0.01 to 5 percent by weight of a substantially sulfur-free alkyl phosphate amine salt, where at least 30 mole percent of the phosphorus atoms are in an alkyl pyrophosphate salt structure, exhibits good antiwear performance. In the phosphate amine salt, at least 80 mole percent of the alkyl groups are typically secondary alkyl groups of 3 to 12 carbon atoms.

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.

Systems and methods for automatic maintenance of lube oil quality include a storage tank for storing fresh lube oil, a lube oil reservoir containing a volume of operational lube oil, and an oil disposal tank. A first controllable flow system transports lube oil from the reservoir to the oil disposal tank, and a second controllable flow system transports fresh lube oil from the storage tank to the reservoir. Provided are a level transmitter to measure a level of lube oil within the reservoir and an antioxidant sensor to measure a concentration of antioxidant level inside the lube oil reservoir. A control system activates and deactivates the first controllable flow system based upon the concentration of antioxidant measured by the antioxidant sensor, and activates and deactivates the second controllable flow system based upon the level of lube oil measured by the level transmitter.

A lubricant formulation for an electric or hybrid vehicle includes a base oil, or a blend thereof, one or more additives, and a molybdenum amine complex, such as diisotridecylamine molybdate, are provided. Lubricant formulations can be characterized by one of: improving electric motor protection when a volatage is applied to an electrode in the presence of a formulation comprising the diisotridecylamine molybdate additive as compared to a fluid lacking the diisotridecylamine molybdate additive; maintaining the electrical resistance slope of a formulation comprising the diisotridecylamine molybdate additive as compared to a fluid lacking the diisotridecylamine molybdate additive; the formulation forming a protective film on copper surfaces; a change in color of the formulation indicating contact load, temperature, time, or viscosity change.

The present disclosure relates to methods and compositions for making bio-based, biodegradable, and non-bioaccumulating lubricating base oils generated by esterifying alkoxylated polyols (average alkoxylation ≥3) with long-chain (≥C14) saturated and unsaturated fatty acids (FA) or fatty acids modified using industry recognized techniques.

Provided is a lubricating oil composition containing a mineral base oil (A) having a temperature gradient Δ|Dt| of a distillation temperature between two points of a distillation amount of 2.0% by volume and a distillation amount of 5.0% by volume in a distillation curve of 6.8° C./% by volume or less, and an antioxidant (B) containing an amine-based antioxidant (B1), a phenol-based antioxidant (B2), and a phosphorus-based antioxidant (B3), wherein the content of the component (B3) is 0.06 to 1.0% by mass based on the total amount of the lubricating oil composition. The lubricating oil composition is a long-life lubricating oil composition that maintains excellent oxidation stability even for long-term use in a high-temperature environment, and has a high effect of suppressing the generation of sludge for a long period of time.

A lubricating composition suited to use for lubricating a hydraulic system includes an oil of lubricating viscosity and a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or metal salt thereof, wherein the wherein the polyolefin is derived from a isobutylene having a number average molecular weight of 150 to 800.

The invention relates to a seal swell agent which is a substituted sulfonyldibenzene compound, and lubricating compositions containing the seal swell agent. The substituents on the benzene rings may be hydrocarbyl groups of 4 to 20 carbon atoms or alkylene groups of 1-2 carbon atoms with further functional groups.

The invention relates to phosphorous-containing compounds useful as antiwear additive components, lubricant additive compositions and lubricant compositions each comprising such compounds, methods for making and using the same, including methods of lubricating machines and machine parts and methods of extending the useful life of elastomeric seal components of such machines.