GB932500A - Fuel compositions - Google Patents

Abstract

A fuel composition comprises (a) a major proportion of a hydrocarbon mixture having an ASTM-boiling range below 205 DEG C. and comprising no more than 50% by volume of aromatics, no more than 30% by volume of olefins, no more than 20% by volume of isoparaffins boiling above 150 DEG C., no more than 20% by volume of aromatics boiling above 150 DEG C., no more than 10% by volume of normal paraffins having 5 or 6 carbon atoms per molecule, no more than 10% by volume of naphthenes boiling above 150 DEG C., essentially no normal paraffins having more than 6 carbon atoms per molecule, and having an equivalent amount (Ae) of co-antiknock antagonist not exceeding 50+0,75 N wherein Ae and N are as defined below; (b) an octane number-improving amount of tetraalkyllead, and (c) a minor proportion of an organic boron coantiknock agent having one of the following formulae I. (RO)3B II. (RO)3B3O3 III. RB(OH)2 <FORM:0932500/III/1> wherein R is a monovalent organic radical having the available valence bond on a carbon atom, having from 1 to 15 carbon atoms and containing no atoms other than carbon, hydrogen, oxygen and nitrogen, R1 is a monovalent or a divalent group, having the available valence bonds on separate carbon atoms which are removed from each other by two or three carbon atoms, having from 1 to 15 carbon atoms and containing no atoms other than carbon, hydrogen, oxygen and nitrogen, and x is a whole number from 1 to 3 inclusive, the amount of co-antiknock agent corresponding to from 0,003 to 0,300 grams of boron present in the co-antiknock agent per gram of lead present in the tetraalkyllead. Suitable boron compounds include alkyl, cycloalkyl, alkenyl, aryl, arylalkyl, alkylaryl, or heterocyclic borates, boroxines, hydroxyboranes and aminoboranes. The compositions may also contain halide lead scavengers, anti-foulants such as tricresylphosphate, dimethylxylyl phosphate or diphenylcresylphosphate, combustion modifiers such as alkyl boronic acids and lower alkyl phosphates and phosphites, oxidation inhibiters such as N,N1-disalicylal-1,2-propane-diamine, and rust inhibitors such as polymerized linoleic acids and N,C-disubstituted imidazolines. The total equivalent amount (Ae) of co-antiknock antagonists is defined by the formula <FORM:0932500/III/2> wherein Al=per cent by volume of aromatics boiling below 150 DEG C. Ah=per cent by volume of aromatics boiling above 150 DEG C. Ao=per cent by volume of olefins. Ap=per cent by volume of C5-plus normal paraffins and naphthenes boiling above 150 DEG C. N =per cent by volume of naphthenes boiling below 150 DEG C.