The invention relates to lubricating greases based on alkali metal soaps and/or earth-alkali metal soaps and metal complex soaps based on (R)-10-hydroxyoctadecanoic acid and to the use thereof.

The invention relates to a composition preparation method for preparing a composition of estolides, the method comprising reacting an unsaturated compound of a type such as an acid or ester, with a saturated fatty acid; in the presence of a catalyst of a type such as sulphonic acid, the said method including no vacuum distillation step thereby making it possible to separate the monoestolides from the polyestolides. The invention also relates to a composition of estolides that is obtainable by the method according to the invention and the use thereof in lubricating compositions.

A lithium complex hybrid grease is based on a lithium complex grease in combination with a PFPE grease. The lithium complex hybrid grease can be used at higher temperatures, does not form layers in the process, and exhibits a low hardening tendency. The lithium complex hybrid grease is usable in components in the automotive field and in the industrial field.

The invention relates to lubricating greases based on alkali metal soaps and/or earth-alkali metal soaps and metal complex soaps based on (R)-10-hydroxyoctadecanoic acid and to the use thereof.

The invention relates to a composition preparation method for preparing a composition of estolides, the method comprising reacting an unsaturated compound of a type such as an acid or ester, with a saturated fatty acid; in the presence of a catalyst of a type such as sulphonic acid, the said method including no vacuum distillation step thereby making it possible to separate the monoestolides from the polyestolides. The invention also relates to a composition of estolides that is obtainable by the method according to the invention and the use thereof in lubricating compositions.

A use of a hemimellitic acid ester of formula I as a base oil a lubricant composition for lubricating tribological systems. In some embodiments, R.sub.1, R.sub.2 and R.sub.3, are independently of one another: a C.sub.5 to C.sub.20 aromatic group, a C.sub.5 to C.sub.20 cycloalkyl group, an unsubstituted, branched or unbranched C.sub.1 to C.sub.20 alkyl group, and/or a C.sub.1 to C.sub.5 alkyl group comprising at least one substituent selected from the group consisting of cycloalkyl groups and aromatic groups. In some embodiments, the hemimellitic acid ester of formula I is provided as a mixture of different compounds of formula I and/or the hemimellitic acid ester of formula I comprises groups R.sub.1, R.sub.2 and R.sub.3 at least partially differing from one another.