Modification of liquid hydrocarbons

A method for dissolving, in a liquid aliphatic hydrocarbon fuel having a flash point not less than 90.degree. F., a copolymer obtained from monomers consisting of (1) at least 75% by weight of tert-butylstyrene as one monomer, (ii) from 1% to 24% by weight of a second monomer selected from the acrylic and methacrylic esters of aliphatic monohydric alcohols containing from 1 to 4 carbon atoms, 2-ethoxyethyl methacrylate, acrylonitrile, vinyl acetate, styrene and vinyltoluene, and (iii) from 1% to 10% by weight of methacrylic acid as a third monomer, the aggregate of monomers (i), (ii) and (iii) being 100% and the copolymer having the following characteristics:

• (a) it is soluble in AVTUR 50 aviation kerosene;
• (b) a 0.3% by weight solution of the copolymer in AVTUR 50 aviation kerosene has a relative viscosity in the range 1.3 to 2.6 and a differential orifice flow rate in the range 3 to 7 ccs per 30 seconds,
• the method consisting in the steps of (A) blending the copolymer in finely divided form with a hydroxylic liquid which is a non-solvent for the copolymer or only a weak swellant therefor but which is miscible to the extent of at least 1% by weight with the fuel;
• (B) mixing the blend of the copolymer and the hydroxylic liquid into the fuel so as to give a concentration of copolymer in the fuel of from 0.1% to 1% by weight;
• and (C) dissolving in the fuel so treated from 0.01 to 0.6 mole, based on each 100 g of copolymer present, of an amino compound selected from the group consisting of alkyl monoamines containing from 1 to 12 carbon atoms, alkanolamines containing from 4 to 10 carbon atoms, aromatic amines and heterocyclic amines.