Abstract: It is disclosed that succinic acid and its derivatives that contain a branched aliphatic group on the 2 or alpha position of succinic acid form surfactants that exhibit a high order of or bioresistance to bacteriological degradation. Further, it has been discovered that these novel surfactants can be employed to prepare novel oil-in-water emulsions with lube oils such as mineral oil that are effective as cutting fluids for machining operations but provide an improved resistance to biodegradation to the cutting oil so formulated, without resorting to the inclusion of conventional biocides in the formulation. It has also been discovered that the bioresistance of the cutting fluid emulsion formulation can be further enhanced by using a branched aliphatic hydrocarbon oligomer or polymer as the lubricative component in the formulation. Cutting fluid emulsions so formulated are effective fluids in prolonging tool life and facilitating machining operations.

Abstract: The invention relates to bioresistant surfactants and cutting fluid compositions which utilize them. The surfactants consist of soaps of carboxylic acid compounds having from 10 to 30 carbon atoms, the carbon skeleton of which is branched and not straight chain. It is the branching which lends the resistance to biodegradation to the products of the invention. Further enhanced bioresistance may be obtained by utilizing a branched lubricating basestock material in the cutting fluid composition.