Patent GB-690591-A (GB)
Title: Processes for the preparation of solutions of petroleum sulphonates in mineral oil
IPC: C07C309/62
Filed: 1951-03-16
Abstract: Petroleum sulphonates in mineral oil solution are prepared by mixing with a mineral oil the crude alkali metal sulphonates obtained by extraction with alcoholic aqueous alkali of a mineral oil which has been treated with sulphuric acid or oleum and removal of the alcohol from the extract, adding to the resulting mixture of oil and crude sulphonates sufficient of a liquid mineral acid to convert the whole quantity of sulphonates into the free sulphonic acids, separating the resulting layer of mineral oil containing the sulphonic acids from the aqueous layer and converting the sulphonic acids in the mineral oil into sulphonates by treatment of the oil with a base.  The crude alkali metal sulphonates, which need not be dry but may contain say 10-40 per cent water, are preferably mixed with the mineral oil to provide a 10-25 per cent solution.  Suitable mineral oils are spindle oils of viscosity 2-3 DEG  Engler at 20 DEG  C.  The addition of mineral acid, e.g. sulphuric acid is preferably effected in stages at 20-40 DEG  C., the acid desirably being in excess, with separation of the aqueous salt layer formed after each addition.  The mineral oil solution of free sulphonic acids may be neutralized with ammonia or caustic soda; preferably the final solution should be slightly alkaline and contain between 8-25 per cent sulphonates and 1-4 per cent water.  The product has emulsifying properties and may be used to prepare emulsions with water having rust-preventing properties (see Group III).  Examples are given utilizing as starting materials, crude sodium sulphonates obtained by treating naphthenic spindle oil with oleum and extracting with aqueous alcoholic caustic soda and the final products are obtained as the ammonium or sodium sulphonates in spindle oil; to reduce viscosity of the final product, a portion, e.g. 0.25 to 0.75 per cent of a phosphoric acid, such as metaphosphoric acid, is added to the solution before finally treating with the base.ALSO:Aqueous emulsions are prepared by adding a solution of petroleum sulphonates in mineral oil to water.  Emulsion stabilisers may be present such as alcohols, esters of higher alcohols, higher ethers, phenols, organic bases and salts of organic bases e.g. ethanol, n-butanol, ethylene glycol, mono-ethyl ether of diethylene glycol, cresol, triethanolamine, triethanolamine oleate and triethylene glycol oleate, and di-isopropyl naphthalene sodium sulphonate.  The oil solution, which may contain about 8-30 per cent sulphonates, may also contain a small amount of a phosphoric acid e.g., meta-phosphoric acid to reduce its viscosity.  The emulsions normally contain about 0.5 to 5.0 per cent of such an oil solution. The emulsions have anti-corrosion properties and may be used in metal working e.g. drilling, milling and drawing and in cooling water-circuits such as motor-car radiators and hydraulic circuits. Examples describe mineral oil solutions prepared in specified manner and comprising sodium or ammonium spindle oil sulphonates in spindle oil solution, (see Group IV (b)).