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 ester compounds of the general formula (I)

##STR00001##

to a process for preparation thereof and to the use thereof. These ester compounds may contain a mixture of at least two compounds of the general formula (I).

A lubricating oil composition including 100 mass parts of (A) an ester compound, 0.05 to 1.5 mass parts of (B) an amine salt of an acidic phosphoric ester and 0.01 to 0.50 mass parts of (C) a monoesterified compound, wherein (A) the ester compound is an ester compound of trimethylolpropane, a straight-chain saturated fatty acid having a carbon number of 8 to 10 and adipic acid; (B) the amine salt is an amine salt of an acidic phosphoric ester; and (C) the monoesterified compound is a monoesterified compound of an alkane diol having a carbon number of 3 to 8 and of succinic acid having an alkyl group having a carbon number of 8 to 18 or an alkenyl group having a carbon number of 8 to 18.

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.

Implementations of the disclosed subject matter provide a lubricating composition for use as a transmission fluid in an electric vehicle. The lubricating composition may include at least 70 wt %, based on the overall weight of the lubricating composition, of a biodegradable ester base oil with a kinematic viscosity at 100 C. in the range of 2.5 to 7.0 mm.sup.2/s. The ester is biodegradable according to OECD test guidelines series 301. The composition may also include at least 0.5 wt % and no more than 10 wt %, based on the overall weight of the lubricating composition, of a viscosity index improver which is at least one high viscosity ester with a kinematic viscosity at 100 C. of at least 1000 mm.sup.2/s; an anti-foam additive selected from silicone oil based antifoam additives and polyacrylate antifoam additives. Also disclosed is a process for lubricating an electric vehicle drive train comprising a transmission by applying the lubricating composition to the transmission.

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.

To provide a composition for a heat cycle system having favorable lubricating properties and comprising a working fluid for heat cycle which has a low global warming potential and which can replace R410A and a heat cycle system employing the composition. A composition for a heat cycle system comprising a working fluid for heat cycle containing trifluoroethylene, and a refrigerant oil (for example, an ester refrigerant oil, an ether refrigerant oil, a polyglycol refrigerant oil or a hydrocarbon refrigerant oil), and a heat cycle system employing the composition for a heat cycle system.

The invention relates to novel ester compounds of the general formula (I) ##STR00001##
to a process for preparation thereof and to the use thereof. These ester compounds may contain a mixture of at least two compounds of the general formula (I).

A lubricating oil composition including 100 mass parts of (A) an ester compound, 0.05 to 1.5 mass parts of (B) an amine salt of an acidic phosphoric ester and 0.01 to 0.50 mass parts of (C) a monoesterified compound, wherein (A) the ester compound is an ester compound of trimethylolpropane, a straight-chain saturated fatty acid having a carbon number of 8 to 10 and adipic acid; (B) the amine salt is an amine salt of an acidic phophoric ester; and (C) the monoesterified compound is a monoesterified compound of an alkane diol having a carbon number of 3 to 8 and of succinic acid having an alkyl group having a carbon number of 8 to 18 or an alkenyl group having a carbon number of 8 to 18.