GB698963A - A method of preparing metallic soaps of fatty acids - Google Patents

Abstract

A metallic soap of a fatty acid containing more than 6 carbon atoms is obtained by forming an aqueous emulsion of said acid in molten condition and slowly adding said emulsion to an agitated aqueous suspension of an oxide or hydroxide of lithium, calcium, strontium, barium, magnesium, aluminium, zinc or lead in the presence of a nitrogenous base which, at room temperature, has the characteristic features of water solubility in excess of 500 grams per litre, an ionization constant greater than 10-9 and a pH value exceeding 9.0 in one tenth normal aqueous solution. The nitrogenous bases which may be used include ammonium hydroxide, simple as well as substituted primary, secondary and tertiary alkyl amines, alkylolamines, quaternary alkylol ammonium hydroxides, certain cyclic and heterocyclic amines, guanidine and certain amino acids, alkyl diamines and polyalkylpolyamines. Specified bases are acetamidine, allylamine, 4 - amino - 2 - butanol, 2 - aminoethylethanolamine, N - aminoethyl morpholine, 2 - amino - 2 - ethyl (or methyl) - 1,3 - propanediol, 2 - amino - 2 - methyl - 1 - propanol, ammonium hydroxide, arginine, n - butylamine, 1,3, - di - aminobutane, diethanolamine, diethylamine, diethylaminoethanol, dimethylethanolamine, dimethylisopropanolamine, dipropylenetriamine, N-ethylmorpholine, guanidine, hydrazine, hydroxylamine, lysine, methallylamine, monoethanolamine, monoethylamine, monoisopropanolamine, monoisopropylamine, morpholine, piperidine, propylenediamine, pyrrolidine, semicarbazide, tetraethanolammonium hydroxide, triethanolamine, triethylamine and triethylenetetramine. The nitrogenous base may be added to the reaction components either in the form of a free base or in the form of an amine or amino acid which forms a free base in aqueous media or in the form of a salt, e.g. a hydrochloride, sulphate, or oxalate such as ammonium oxalate, ammonium sulphate, guanidine sulphate, or semicarbazide hydrochloride which frees the base by a replacement reaction with the metallic hydroxide in aqueous media. The nitrogenous base is generally added in an amount of from 0.10 to 0.60 per cent by weight of the total mixed suspension. A small proportion of an emulsifying agent, e.g. ammonium hydroxide, may be added to maintain an emulsion of the fatty acid at 5 DEG to 10 DEG C. above its melting point. Examples describe the production of (1) calcium stearate, using pure stearic acid, calcium oxide and diethanolamine; (2) zinc laurate using commercial grade lauric acid, zinc oxide and morpholine; (3) dibasic lead stearate using commercial grade stearic acid lead monoxide and triethanolamine; (4) dibasic lead stearate by adding to an aqueous suspension of litharge containing monoethanolamine an aqueous emulsion of commercial grade stearic acid containing ammonium hydroxide and emulsifying agent; normal lead stearate may also be prepared in the same way by changing the relative amount of stearic acid; (5) barium ricinoleate is obtained by adding an aqueous emulsion of molten castor oil fatty acids concentrated ammonium hydroxide p being used as emulsifier to an aqueous suspension of barium hydroxide. Other fatty acids mentioned are caprylic, myristic, palmitic, hydroxy stearic, arachidic, and behenic and the production of dibasic lead palmitate, myristate, and laurate is also referred to.