Provided is an engine oil lubricant composition with improved fuel efficiency and engine wear protection. The lubricant composition may include a major amount of an oil basestock from any one or more Group I, Group II, Group III, Group IV or Group V base oils. The resulting engine oil lubricant composition may have a kinematic viscosity at 100° C. of 6 cSt or less, and a corrosion protection of at least 90, as measured according the ASTM D6557 Ball Rust Test. The resulting engine oil lubricant composition may also have a kinematic viscosity at 100° C. of 6 cSt or less, an HTHS (ASTM D4683) of less than or equal to 2.2 cP at 150° C. and a FZG failure load stage of at least 6, as measured by the FZG A10/16.6R/130 test procedure.

Provided are: an ionic liquid including the fluorine-containing phosphate ester anions represented by formula (1); and a lubricating oil composition including said ionic liquid. ##STR00001## (In the formula, Rf represents a C1-14 perfluoroalkyl group. R.sup.1 represents a C1-8 alkyl group.)

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a mixture of boron-containing and boron-free dispersants, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating compositions may improve one or more of cleanliness, TBN retention, fuel economy and low-speed preignition (“LSPI”).

There is provided a grease composition for improving the chemical stability of the grease composition and increasing the fatigue life of a member in which the grease composition is used. The problems can be solved by a grease composition including a poly-α-olefin; a urea-based thickener; molybdenum dithiophosphate; and barium sulfonate, wherein a difference between an SP value of the urea-based thickener and an SP value of the poly-α-olefin is 3.5 or less.

A refrigerating machine oil containing: a lubricating base oil; and a compound represented by the following formula (1): ##STR00001## wherein R.sup.1 and R.sup.2 each independently represent a monovalent hydrocarbon group, R.sup.3 represents a divalent hydrocarbon group, and R.sup.4 represents hydrogen atom or a monovalent hydrocarbon group, and the refrigerating machine oil having a kinematic viscosity at 100° C. of 0.5 mm.sup.2/s or more and 2.5 mm.sup.2/s or less.

The invention discloses a lubricating grease with thixotropy and a preparation method thereof. The lubricating grease comprises a polyurea/high base number calcium sulfonate composite thickener, colloidally dispersed calcium carbonate solid particles in the form of calcite, a calcium borate or calcium borate composite, and a calcium soap of fatty acid having 12 to 24 carbon atoms. The above components are uniformly dispersed in an oil phase medium. The content of high base number calcium sulfonate in the lubricating grease is less than 22 wt %.

The invention relates to an imide polymer-based solid film lubricant, a method for producing same, a sliding element comprising same and the use thereof. According to the method, difunctional or cyclized difunctional compounds and optionally functional fillers are added to a non-imidized or partly imidized polyamide acid prepolymer or an imidized short-chain blocked prepolymer in a solvent or solvent mixture and then, depending on the prepolymer, a polymerization reaction or an imidization reaction and in both cases a crosslinking reaction is carried out. The solid film lubricant comprises an imide polymer as the resin matrix and optionally functional fillers, the molecules of the imide polymer comprising groups (R.sub.1) of the difunctional compounds that additionally contribute to the crosslinking.

A lubricating oil composition excellent in the wear resistance and a refrigerator oil composition excellent in the oxidation stability using the lubricating oil composition are provided by a lubricating oil composition containing a base oil (A) and a phosphine derivative (B) having one or more oxygen atom in a molecule.

Lubricant composition comprising:

at least one base oil; and

0.1 to 30% by weight of an imidazoline compound of formula (A):

##STR00001##

defined such that:

R.sup.1 represents a linear or branched alkyl or alkenyl group comprising 1 to 16 carbon atoms, optionally substituted at the end of the chain by a group selected from among NH.sub.2, OH or SH; and

R.sup.2 represents a linear or branched alkyl or alkenyl group comprising 1 to 36 carbon atoms.

A lubricant composition comprising: at least one base oil; and from 0.1% to 30% by weight of a phosphorus ester compound of formula (A):

##STR00001## in which s is 0 or 1; and the radicals X represent, independently of each other, —OR′ or R′ moieties, where R′ represents hydrogen or a linear or branched hydrocarbon moiety, preferably having from 1 to 36 carbon atoms, with the proviso that: when s is 0, the three X radicals represent —OR′ moieties, and when s is 1, at least two of the three X radicals are —OR′ moieties.