Unilever Patent Holdings B.v.

Unichema Chemie B.v.

Dirk Kenbeek

Eric Appelman

Hendrik Leendert Rieffe

Gijsbert Van Der Waal

Ramires Rolando Poulina

Cornelis Verboom

An ester resulting from an esterification reaction between at least one polyfunctional alcohol and at least one polyfunctional carboxylic acid using a chain stopping agent to form ester bonds with the remaining hydroxyl or carboxyl groups is disclosed. The polyfunctional carboxylic acid comprises an aliphatic dicarboxylic acid containing from 9 to 18 carbon atoms, dimerised and/or trimerised fatty acids or mixtures thereof, with the proviso that dimerised and trimerised fatty acids do not constitute more than 80% by weight of the total amount of polyfunctional carboxylic acid used. The chain stopping agent may be a monocarboxylic acid or a monofuntional alcohol having at least 14 carbon atoms. The complex esters have a kinematic viscosity at 100 C of from 30 to 1000 cSt, preferably from 30 to 200 cSt. The complex ester is useful &ldquo;as is&rdquo; or as an additive and/or as a base fluid and/or a thickener in transmission oils, hydraulic fluids, four-stroke oils, fuel additives, compressor oils, grease, chain oils and for metal working metal rolling applications. A multigrade gear oil formulation comprising one of more of the above complex esters is also part of the invention.

Complex esters, formulations comprising these esters and use thereof

An ester based lubricant, particularly suitable for 4-stroke engines comprises at least one ester of a saturated, branched chain monohydric alcohol having at least 8 carbon atoms and a saturated branched chain aliphatic monocarboxylic acid having at least 10 carbon atoms. The esters have a kinematic viscosity of at most 35 cSt (40&deg; C.), a non-polarity index of at least 100, a Noack evaporation loss of at most 10% and a pour point below &minus;30&deg; C.

Lubricant

The invention provides a polyester based on dimeric fatty acid, a glycol without hydrogen atoms at an alpha carbon atom in which a C3-C12 monoalcohol chainstopper is present and which contains approximately equivalent quantities of acid and alcohol groups. Preferably the dimer acid contains 36 carbon atoms and the monoalcohol is a branched chain C6-C10 alkanol. The invention also provides lubricant compositions comprising 30-2% (w.w.) of the polyester and 70-98% (w.w.) of an synthetic lubricant base.

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Oudewater, Netherlands

Dirk Kenbeek