GB706644A - Mineral oil compositions containing sulphur-containing anti-oxidants - Google Patents

Abstract

Sulphur-containing compounds are prepared by reacting "acid oils" with unsaturated aliphatic or cyclo aliphatic hydrocarbons having one or more double bonds and freeing the resulting sulphur-containing reaction products from unreacted components and resinous by-products. The acid-oils are derived from sulphur-containing waste products obtained in the refining of cracked gasoline with an alkaline solution, e.g. 18 per cent. aqueous sodium hydroxide; the aqueous alkaline extract, after removal of any entrained gasoline, is acidified with a strong acid whereupon two layers are formed, the upper one being the "acid oils" which are washed free of any residual strong acid, e.g. with sodium chloride solution and then distilled from resinous substances. The unsaturated hydrocarbon reactants may have an open straight or branched chain or a cyclic structure in the molecule; they preferably have at least 5 carbon atoms, alkenes having 10-18 carbons being particularly useful, and they may be obtained by cracking higher paraffinic hydrocarbons including paraffin wax. The reaction between the acid oils and unsaturated hydrocarbons may be effected at room temperature but preferably elevated temperatures, e.g. 110 DEG -200 DEG C. are used; ultra violet light or peroxides may be used as accelerators. Generally 1 gm. mol. of hydrocarbon is reacted with a quantity of acid oils containing 2 gm. atoms of bound sulphur. The products are anti-oxidants for insulating oils and lubricating compositions (see Group III). In an example, an acid oil obtained by alkaline extraction of a Dubbs cracked gasoline is heated with a mixture of C 14-18 alkenes at 180 DEG C., then distilled under reduced pressure to remove unreacted components and the residue distilled under lower pressure to recover the desired product which is deodorised by washing with alcoholic sodium hydroxide.ALSO:A mineral oil composition comprises a minor proportion which is at least 0.01 per cent. by weight, calculated as sulphur content, of a sulphur-containing product having anti-oxidant properties and obtainable by a process wherein "acid oils" are reacted with unsaturated aliphatic or cycloaliphatic hydrocarbons having one or more double bonds and the resulting sulphur-containing product is freed from unreacted components and resinous by-products (see Group IV (b)). The "acid-oils" are derived from sulphur-containing waste products obtained in the refining of cracked gasoline with an alkaline solution, e.g. 18 per cent. aqueous sodium hydroxide; the aqueous alkaline extract, after removal of any entrained gasoline, is acidified with a strong acid whereupon two layers are formed, the upper one being the "acid oils" which are washed free of any residual strong acid, e.g. with strong sodium chloride solution, and then distilled from resinous substances. The unsaturated hydrocarbons may have an open straight or branched chain or cyclic structure and preferably contain at least 5 carbon atoms, especially 10-18; they may be those obtained by cracking higher paraffinic hydrocarbons, e.g. paraffin wax. The products may be added to lubricating oils and greases and insulating oils. An example describes the preparation of a product from a mixture of C14-18 alkenes and acid oils derived from a cracked Dubbs gasoline and its anti oxidant properties with regard to a lubricating oil.