GB708000A - Improvements relating to liquid synthetic detergent compositions - Google Patents

Abstract

Dialkylolamides of fatty acids which contain 10 to 14 carbon atoms are prepared by condensing fatty acylating compounds such as the acid, its ester, acid anhydride or acyl halide with a dialkylolamine, the latter reactant being preferably in excess. Suitable molar ratios of acylating compound to dialkylolamine lie bebetween 1 : 1 and 1 : 10, preferably about 1 : 2 to about 1 : 3, the reaction being carried out between about 100 DEG C. and about 200 DEG C. A complex mixture of products is formed, and in order to obtain an equilibrium mixture containing an effective proportion of the dialkylolamide the product may be cooled relatively slowly or held at a slightly elevated temperature for a period of time. A typical reaction mixture from lauric acid (90 per cent pure) and diethanolamine may contain 65 per cent diethanolamide, 10 per cent diethanolamine soap and 25 per cent diethanol-piperazine and other substances including water. The fatty acylating substances may be derived from pure, impure or mixtures of capric, lauric, and myristic acids. Mixtures of these acids derived from natural sources and containing acids of higher and lower molecular weight may also be used, such as "topped" coconut oil fatty acids. Suitable dialkylolamines for the reaction include, besides diethanolamine, N,N - bis - (2,3 - dihydroxypropyl) - amine, dipropanolamine, N,N - bis - (2-hydroxylpropyl) - amine and dibutanolamine. Dialkylolamides specified include N,N-bis-(2-hydroxyethyl) - lauramide, N,N - bis - (2-hydroxyethyl) - capramide, N,N - bis - (2-hydroxyethyl) - myristamide, N,N - bis - (2,3-dihydroxypropyl) - lauramide, N,N - bis - (2,3-dihydroxypropyl) - myristamide, N,N - bis - (3-hydroxypropyl) - lauramide, N,N - bis - (3-hydroxypropyl) - capramide, N,N - bis - (2-hydroxypropyl) - myristamide, and N,N - bis-(4-hydroxybutyl)-lauramide. The dialkylolamides may be incorporated in detergent compositions (see Group III).ALSO:A liquid detergent composition comprises a water-soluble anionic sulphated or sulphonated detergent containing an aliphatic chain of at least 8 carbon atoms, a dialkylolamide of a fatty acid which contains 10 to 14 carbon atoms and a solvent for the detergent and the dialkylolamide. Suitable solvents include the low molecular weight hydroxyl containing solvents, particularly water, saturated aliphatic alcohols or aqueous saturated aliphatic alcohols. Specified alcohols include ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, ethylene glycol, propylene glycol, glycerol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. Dioxan may also be used. It is preferred to use water, mono- or di-hydric alcohols containing 2 to 4 carbon atoms in the molecule, lower (i.e. C1-C5) alkyl ethers of these dihydric alcohols and mixtures of these solvents The dialkylolamide may be of general formula RCO-NR1R11, where RCO represents a fatty acyl radical containing 10 to 14 carbon atoms and R1 and R11 are the same or different hydroxyalkyl groups of 1-5 carbon atoms. These hydroxyalkyl groups may be mono-or polyhydroxy in character. Specific dialkylolamide additives include N,N - bis - (2 - hydroxyethyl) lauramide, H,N-bis-(2-hydroxyethyl) capramide, N1N-bis-(2-hyroxyethyl) myristamide, N,N-bis-(2, 3-dihydroxypropyl) lauramide, N,N-bis-(2, 3-dihydroxypropyl) myristamide, N,N-bis-(3-hydroxypropyl) lauramide, N,N-bis- (3-hydroxypropyl) capramide, N,N-bis-(2-hydroxypropyl) myristamide and N,N - bis - (4-hydroxybutyl) lauramide. Diethanolamide compounds are preferred. (For preparation of these dialkylolamides see Group IV (b)). Impurities such as soap, free alkylolamine and piperazine type derivatives may result as by-products during the manufacture of the dialkylolamides, and provided that these impurities are not present in such amounts as to interfere with the detergent action of the final composition, the dialkylolamide product containing them may be used without further purification. The sulphated or sulphonated detersive compound may be an aliphatic acylcontaining compound containing 8 to 22 carbon atoms in the acyl group such as the sulphated or sulphonated aliphatic carboxylic esters containing 10 to 26 carbon atoms in the molecule. Other specified detergents include the sulphuric acid esters of polyhydric alcohols incompletely esterified with higher (i.e. at least 8 carbon atoms) fatty acids such as coconut oil monoglyceride monosulphate or tallow diglyceride monosulphate; pure or mixed higher alkyl sulphates such as lauryl sulphate, cetyl sulphate and fatty alcohol sulphates derived from reduced coconut oil fatty acids; the hydroxy sulphonated higher fatty acid esters such as the higher fatty acid esters of 2, 3-dihydroxypropane sulphonic acid; the higher fatty acid esters of lower alkylol sulphonic acids such as the oleic acid ester of isethionic acid; the higher fatty acid ethanolamide sulphates; and the higher fatty acid amides of amino alkyl sulphonic acids, e.g. lauric acid tauride. The higher alkyl-aryl sulphonates may also be used. The aromatic nucleus may be mononuclear or polynuclear in structure, and may be derived from benzene, toluene, xylene, phenol, cresols or naphthalene. The alkyl substituent may be straight or branched-chain in structure; specified alkyl groups include decyl, dodecyl, keryl, pentadecyl, hexadecyl and mixed alkyl groups containing at least 8 carbon atoms derived from long-chain fatty materials, cracked paraffin wax olefins or polymers of olefins such as propylene tetramer. The alkyl group may have 8 to 22 carbon atoms, and preferably 12-18. The detergents may be used as their water-soluble amine, alkali-metal or alkaline-earth metal salts, preferably the alkylolamine (especially mono-, di- and triethanolamine) salts. The ratio of dialkylolamide to anionic detergent may be between about 1 : 10 to about 2 : 1 by weight, preferably from about 1 : 7 to about 1 : 1 by weight. Depending on the solvent power of the selected solvent, the amount of total solids in the composition may be from about 30 per cent. to about 90 per cent., preferably at least 40 per cent. The amount of anionic detergent may be 40-60 per cent. and that of dialkylolamide 10-20 per cent. The dialkylolamide may be incorporated in the detergent at any stage of the manufacturing process, but it is preferred to add the molten dialkylolamide to a warm water, aqueous alcohol or alcohol solution of the detergent or to dissolve the dialkylolamide in alcohol or water and add the so formed solution to the detergent. Further dilution to the desired concentration may be necessary. In an example (all parts by weight) 13 parts of lauric diethanolamide, 44.7 parts of the triethanolamine salt of dodecyl benzene sulphonate, 7.5 parts of triethanolamine sulphate, 22.3 parts of water and 12.5 parts of ethyl alcohol are mixed to form a detergent composition.