Provided is a mold release agent composition containing a polymer ester, the composition exerting a good mold releasability even when the temperature of mold increases, and a die casting method using the composition.

Estolide esters obtainable by esterification of —hydroxycarboxylic acids having 12 to 24 carbon atoms, the hydroxycarboxylic acids comprising unsaturated hydroxycarboxylic acids having a) —monocarboxylic acids with 6 to 22 carbon atoms and —polyols with at least two hydroxy groups or b) —monoalcohols having 8 to 22 carbon atoms and —linear carboxylic acids having at least two carboxyl groups or c) —monocarboxylic acids having 6 to 22 carbon atoms and —monoalcohols having 8 to 22 carbon atoms.

The invention relates to a method for the preparation of estolide esters from a hydroxycarboxylic acid by a reaction of addition of a fatty acid to the hydroxyl function and by a reaction of esterification of the carboxylic acid function with an alcohol. The invention further relates to the use of estolide esters as a base oil in a lubricating composition or as an emollient in a cosmetic or pharmaceutical composition.

An object of the present invention is to provide a grease composition which has little influence on the environment and has good rust prevention and water resistance against salt water such as sea water. The grease composition comprises a biodegradable base oil and a rust-preventive agent comprising a calcium sulfonate complex and a sorbitan fatty acid ester, wherein a total content of biodegradable organic substances in the grease composition is 75% by mass or more, and wherein a content of the rust-preventive agent is 2.5 to 30% by mass.

An object of the present invention is to provide a grease composition which has little influence on the environment and has good rust prevention and water resistance against salt water such as sea water. The grease composition comprises a biodegradable base oil and a rust-preventive agent comprising a calcium sulfonate complex and a sorbitan fatty acid ester, wherein a total content of biodegradable organic substances in the grease composition is 75% by mass or more, and wherein a content of the rust-preventive agent is 2.5 to 30% by mass.

The present invention describes a process for obtaining a biolubricant from vegetable oil, which comprises the steps of (a) esterification reaction of the product of vegetable oil hydrolysis using a branched aliphatic alcohol; (b) epoxidation reaction of the esters obtained in step (a); and (c) nucleophilic substitution reaction of the epoxidated esters obtained in step (b) using a branched aliphatic alcohol. The present invention also describes a biolubricant obtained from the process. More specifically, a biolubricant is described that is produced from a ricinoleic fatty acid, whose formula is illustrated in FIG. 1 of the present invention, and where R.sub.1 is a hydroxyl or it is from the formula R.sub.3COO.sup.−, with R.sub.3 being an alkyl radical C.sub.1-C.sub.3, preferably a methyl radical; and R.sub.2 consists of a straight chain of hydrocarbons C.sub.4-C.sub.8 and a branched chain of hydrocarbons C.sub.1-C.sub.3.

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.

The present invention relates to a use of a lubricant comprising a base oil selected from a carboxylic acid ester in an electric vehicle. It further relates to a method for lubricating an electric vehicle with a lubricant comprising the carboxylic acid ester.

The present invention provides a method for producing a refrigerating machine oil, comprising blending a hydrocarbyl hydrogen phosphite having an acid value of 100 mgKOH/g or less with a lubricating base oil or an oil composition containing a lubricating base oil, and a refrigerating machine oil obtained by the method.

A lubricant composition comprising an oil-soluble polyalkylene glycol; an ester compound selected from the group of natural esters and synthetic esters, and combinations thereof; and an additive mixture comprising an antioxidant and an anticorrosive, wherein the anticorrosive is selected from neutral alkali metal and alkaline earth metal salts of sulfonic acids, carboxylic acids, naphthoic acids, naphthenic acids, benzoic acids and phosphoric acids, and derivatives and combinations thereof.