GB822699A - Inhibition of carburettor icing - Google Patents

Abstract

A motor gasoline contains a minor amount, sufficient to prevent engine stalling, of an additive consisting of compounds of the general formula <FORM:0822699/III/1> wherein R is a tertiary alkyl group containing between 10 and 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom, e.g. t.-dodecyl, -tetradecyl, -pentadecyl, -hexadecyl, -octadecyl, -eicosyl, -tetracosyl, or -triacontyl. Additions of the above succinamic acids lie between 0.005 and 0.50% by weight of gasoline. They are prepared by reacting succinic acid anhydride with a tertiary alkyl primary monoamine or a mixture of such amines, the mixture of amines being derived from a polyolefin fraction (e.g. polypropylene and polybutylene cuts) by treatment with sulphuric acid and water to convert to the alcohol, then with hydrogen chloride to obtain the alkyl chloride and thence to the t.-alkyl primary amine mixture by condensing the chloride with ammonia under pressure. The gasoline may also include other additives, e.g. anti-knock agents, pre-ignition inhibitors, antirust agents, metal-deactivators, dyes, antioxidants, detergents, and from 0.01 to 1% by weight of solvent oils, e.g. coastal and midcontinent distillate oils having viscosities of from 50 to 500 S.U.S. at 100 DEG F., or synthetic oils such as diester oils, polyalkylene glycols, silicones, phosphate esters, polypropylenes and polybutylenes.ALSO:Compounds of the general formula <FORM:0822699/IV (a)/1> wherein R is a tertiary alkyl group containing between 10 and 30 carbon atoms and having a tertiary carbon atom directly attached to the nitrogen atom, e.g. t-dodecyl, -tetradecyl, -pentadecyl, -hexadecyl, -octadecyl, -eicosyl, -tetracosyl, or -triacontyl, are prepared by reacting succinic acid anhydride with a tertiary alkyl primary monoamine or a mixture of such amines, the mixture of amines being derived from a polyolefin fraction (e.g. polypropylene and polybutylene cuts) by treatment with sulphuric acid and water to convert to the alcohol, then with hydrogen chloride to obtain the alkyl chloride and thence to the t-alkyl primary amine mixture by condensing the chloride with ammonia under pressure. In examples, two amine mixtures consisting of (a) about 85% t-dodecyl, 10% t-pentadecyl, and less than 5% of other amines; and (b) about 40% t-octadecyl, 30% t-eicosyl, 15% t-docosyl, 10% t-tetracosyl, and less than 5% of other amines, are reacted with succinic acid anhydride, xylene being used as diluent for the reaction of amine mixture (a).