| abstract |
A stable aqueous cutting fluid comprises a salt of boric acid and an aliphatic amine, having 1 to 3 aliphatic radicals each with 1 to 4 carbon atoms, and having at least one hydroxy group attached to a carbon atom, the amount of amine being at least the stoichiometric amount and may be up to 100% excess; and the composition also contains 5 to 40 mols. water per mol. of boric acid. The amine is preferably triethanolamine. The composition may also contain an unsaturated fatty acid with 18 to 22 carbon atoms, which may have a single hydroxy group as substituent, in amount of from 1/8 to 2/5 mols. per mol. of boric acid and containing sufficient amine in excess of that stated above to form a salt therewith. Examples include oleic, linoleic, elaidic, linoleric, erucic, eleostearic and ricinoleic acids. Nonionic wetting agents may also be used. These are preferably of the soluble type, e.g. polyethoxy-esters of fatty acids, polyethoxyethers of fatty alcohols, the condensation product of an alkyl phenol with ethylene oxide, the sulphonated product of the condensation of an alkylphenol or an alkylnaphthol with ethylene oxide. A preferred compound is an alkylated aryl polyether alcohol. Another ingredient is an antifoam agent. Many examples are given including silicones and silicates. 1 to 7 g. of a silicone may be used per mol. of boric acid. A gel-forming solvent may also be added to the composition. Alcohols having more than 3 carbon atoms and ethers of these alcohols may be used in amount of from 20 to 60 g. per mol. of boric acid. A rust inhibitor may also be added, e.g. an alkali metal borate or nitrite which also aid gel formation. Potassium compounds are preferred, e.g. 20 to 70 g. potassium tetraborate per mol. of boric acid. A composition for use in said cutting fluid as antifoam agent comprises a mixture of silicones with other antifoam agents, e.g. sulphonated fish oils or high molecular weight saturated fatty acids. The silicones preferably are those in which each saturated hydrocarbon group contains 14 to 24 carbon atoms, the total being at least 24. The hydrocarbon groups may be substituted with alkoxy, nitro, halogen, or esterified sulphonic groups.ALSO:A salt of boric acid and an aliphatic amine having from 1 to 3 aliphatic radicals, each containing 1 to 4 carbon atoms and having at least one hydroxy group attached to a carbon atom is prepared by mixing boric acid with water and the amine. Preferably the boric acid is finely divided and the mixture stirred until it is dissolved. Up to 100% excess of the amine, e.g. triethanolamine, may be used. The salt is used with numerous additives as an aqueous cutting fluid. One such additive is a salt of the amine with an unsaturated fatty acid having 18 to 22 carbon atoms. |