TEMPERATURE-STABLE BIOCIDE COMPOSITION FOR METALWORKING FLUIDS

The invention relates to biocide compositions containing the constituents: (a) between 15 wt. % and 30 wt. % of 1,2-benzisothiazolin-3-one; (b) at least one alkanol amine selected from the group of triethanol amine, triisopropanol amine and alkanol amines with alkyl groups selected from the group of methyl, ethyl, isopropyl, propyl, butyl and mixtures thereof; and (c) at least one compound of the general formula, in which R1, R2, R3 and R4 can be the same or different and each one is a substituted alkyl group containing between 2 and 6 carbon atoms, in which the substituents R1, R2, R3 and R4 have at least one hydroxyl group bound to carbon atoms other than the α-carbon atom, and n is between 2 and approximately 6; and (d) 100 wt. % water, wherein the molar ratio of constituents (a) to the sum of constituents (b) and (c) is in the range of 1:0.7 to 1:2.5, and the molar ratio of the constituents (b) to (c) is in the range of 1:0.1 to 1:20. The invention further relates to the use of said biocide compositions in aqueous liquids such as metal-working liquids.