abstract |
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 "as is" 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. |