Improvements in and relating to the retardation of haze formation in a tetraalkyl lead or in a composition containing a tetraalkyl lead

摘要

Tetra-alkyl lead compositions, particularly solutions of tetra-alkyl lead in stable hydrocarbon motor fuel or in solvents such as benzene, toluene, naphtha, hexanes, heptanes, octanes, nonanes, carbon tetrachloride, chloroform, isopropyl benzene or di-isopropyl ether, are stabilized against haze formation by adding a derivative of p-phenylene diamine wherein one hydrogen atom of each amine group is replaced by a secondary or tertiary alkyl group. The addition is especially useful in the case of anti-knock compositions containing tetra-alkyl lead and halogenated hydrocarbons such as ethylene dibromide or ethylene dichloride or both, or in the case of stable motor fuels, consisting of hydrocarbons with or without other combustible substances such as alcohols, to which such anti-knock compositions have been added. Derivatives of p-phenylene diamine mentioned are N : N1-di - tertiary butyl - p - phenylene diamine, N - secondary butyl - N1-isopropyl - p - phenylene diamine, N : N1-di-secondary butyl-p-phenylene diamine and N : N1 - di - isopropyl - p - phenylene diamine. In examples: (1) an anti-knock composition containing tetraethyl lead, ethylene dibromide and N : N1-di-secondary butyl-p-phenylene diamine and (2) a gasoline containing petrol, tetraethyl lead, ethylene dibromide and N : N1-di-secondary butyl-p-phenylene diamine or N : N1-di-isopropyl-p-phenylenediamine are described.ALSO:Tetra-alkyl lead compositions, particularly solutions of tetra-alkyl lead in stable hydrocarbon motor fuel or in solvent such as benzene, toluene, naphtha, hexanes, heptanes, octanes, nonanes, carbon tetrachloride, chloroform, isopropyl benzene or di-isopropyl ether, are stabilised against haze formation by adding a derivative of p-phenylene diamine wherein one hydrogen atom of each amine group is replaced by a secondary or tertiary alkyl group. Derivatives of p-phenylene diamine mentioned are N : N1-di-tertiary butyl-p-phenylene diamine, N - secondary butyl - N1 - isopropyl - p - phenylene diamine, N : N1 - di - secondary butyl-p-phenylene diamine and N : N1-di-isopropyl-p-phenylene diamine. The examples describe compositions consisting of (1) tetraethyl lead, ethylene dibromide and N : N1-di-secondary butyl-p-phenylene diamine and (2) petrol, tetraethyl lead, ethylene dibromide and N : N1-di-secondary butyl-p-phenylene diamine or N : N1 - di - isopropyl - p - phenylene diamine. Preparation of N-secondary butyl-N1-isopropyl-p-phenylene diamine:-an acetone solution of N-secondary butyl-p-nitroaniline is hydrogenated at elevated temperature and pressure in the presence of a catalyst consisting of copper oxide, chromium oxide and barium oxide.