GB595916A - Improvements in motor fuels - Google Patents

Abstract

A hydrocarbon motor fuel contains as an inhibitor of gum formation a composition comprising N : N1-di(sec.-butyl)-p-phenylene diamine and a phenol, the phenol being present in amount corresponding to about 5-30 per cent. of the weight of the N : N1-di (sec.-butyl)-p-phenylene diamine. Suitable phenols are phenol itself, p-cresol, tert.-butyl catechol, p-isopropyl phenol, 2 : 4-dimethyl-6-tert.-butyl phenol, p-tert.-butyl phenol, p-amyl phenol, p-octyl phenol, p-stearyl phenol, a-naphthol, o- or p-aminophenol, N-phenyl-p-aminophenol, N-benzylp -aminophenol, N-cyclohexylp - aminophenol, and the N-alkyl-p-aminophenols, a number of which are specified. The hydrocarbon motor fuel may contain other ingredients such as appreciable quantities of alcohol or other combustible materials and tetra-ethyl lead or other tetra-alkyl lead compounds. If desired the gum-inhibiting composition may be introduced into the fuel by adding it to an anti-knock composition which is subsequently added to the fuel, the anti-knock composition comprising a tetra-alkyl lead compound and a halogenated hydrocarbon such as ethylene dibromide or ethylene dichloride or both. Specific gum-inhibiting compositions mentioned in the examples are N : N1-di(sec.-butyl)-p-phenylene diamine together with N-(n-primary-butyl)-p-aminophenol, o-cresol or 2 : 4-dimethyl-6-tert.-butyl phenol.