Patent GB-666767-A (GB)
Title: Plastic detergents and method of making same
IPC: C11D10/04
Filed: 1947-11-20
Abstract: Plastic detergent compositions suitable for use as shampoos comprise a sulphated or sulphonated anionic organic detergent and water (with or without an electrolyte) in sufficient amount to place the detergent system predominantly in the "middle phase," the composition having a ready solubility in water and a plasticity such that it is adaptable to using out of a collapsable tube.  Anionic detergents of the above type, and mixtures of these with soaps, are said to form, with water, or water and electrolyte, phase systems having much the same behaviour as soap-water-electrolyte systems and in the Specification the terms "neat phase," "middle phase" and "nigre phase" are applied equally to soap systems and to systems comprising synthetic detergents.  It is also stated that in the manufacture of ordinary soaps there is occasionally formed in the soap kettle, when too much water and too little electrolyte are present, an exceedingly viscous and gummy form of soap which is undesirable because it is immiscible with the other liquid phases present in the soap kettle and is very difficult to blend or convert into a more manageable form.  These so-called "water lumps" or "gum soap" are a distinct phase known as "middle soap" characterized by being relatively low in electrolyte content and intermediate in moisture content between the "neat soap" phase (typified by ordinary finished kettle soap in molten form) and the more watery "nigre soap" phase.  The existence of the detergent compositions of the invention in the pure middle phase region is said to be readily recognized by the rather tough gummy plasticity of the composition and its transparency.  It is also said to have a characteristic appearance when examined in thin films between crossed nicols under the microscope, as described in Jerome Aleander's "Colloid Chemistry," Vol. I, 1926, p. 107.  The detergent composition may contain a water-soluble soap of higher fatty acids and the ratio of synthetic detergent to true soap may be between 9 : 1 and 1 : 9. The basic radicals of the detergents may comprise a substantial proportion of lower alkylolamines having the general formula R, R1, N.X.OH where X is any non-acidic organic residue containing not over 3 carbon atoms, and R and R1 may be hydrogen, any alkyl hydrocarbon radical containing not over six carbon atoms, or any non-acidic alcohol radical containing not over three carbon atoms.  Examples of such lower alkylolamines are the mono-, di-, and tri-ethanolamines and the corresponding normal- and iso-propanolamines, low molecular weight alkyl substituted derivatives such as methyl diethanolamine and dibutyl ethanolamine, mixed alkylolamines such as propanol diethanolamine, cyclohexyl ethanolamine, alkylol polyamines such as ethanol- and propanol-derivatives of ethylene diamine and 1, 2-diamino-propanol and 1-amino 2, 3-propanediol.  The anionic radical of the synthetic detergent may contain 8-26 carbon atoms and the detergent may include the salts of the sulphuric acid reaction products of aliphatic alcohols (e.g. the sodium salt of lauryl or oleyl sulphuric acid or of the sulphuric ester of higher alcohols derived by the reduction of coconut oil), of aliphatic hydrocarbons (e.g. the sodium salt of the sulphuric reaction product of hexadecene), of alkyl aromatic hydrocarbons and their derivatives (e.g. potassium salt of the sulphonic acid derived from the condensation product of benzene and a chlorinated kerosene fraction containing predominantly 12 carbon atoms per molecule), of mono-glycerides of higher fatty acids (e.g. the sodium salt of the coconut oil fatty acid mono-ester of 1, 2-dihydroxy-propane-3-sulphuric acid ester and of the corresponding sulphonic acid), of high molecular weight alcohol esters of low molecular weight carboxylic acids (e.g. the sodium salt of the lauryl ester of sulphonacetic acid), of mono-alkyl glycerol and glycol ethers (e.g. the monolauryl ether of the sodium salt of isethionic acid, the monomyristyl ether of the sodium salt of 1, 2-dihydroxy-propane-3-sulphonic acid, the monolauryl ether of the sodium salt of glycol monosulphuric acid and the triethanolamine salt of the coconut oil higher alcohol ether of 1, 2-dihydroxypropane-3-sulphonic acid), of high molecular weight acyl esters of glycol and diethylene glycol (e.g. the potassium salt of mono-oleoyl diethylene glycol sulphate and the coconut oil fatty acid ester of the sodium salt of isethionic acid), of high molecular weight fatty acid amides of lower molecular alkylolamines (e.g. the sodium salt of sulphated coconut oil fatty acid ethanol amide), of high molecular weight fatty acid amides of lower molecular alkyl amines (e.g. potassium salt of oleic acid amide of N-methyl taurine), and of low molecular weight carboxylic acid amides of alkylolamine esters of high molecular weight fatty acids (e.g. the sodium salt of the sulphoacetamide of amino ethyl laurate.  The synthetic detergents may also include lower alkylolamine and ammonium salts of sulphated and sulphonated detergents having unsaturated and/or relatively short (e.g. not over 12-14 carbon atoms) saturated hydrocarbon chains in their anionic radicals.  The detergent composition may contain a minor proportion of one or both of the more liquid phases, i.e. nigre phase and/or neat phase, dispersed throughout the middle phase.  At room temperature and in the substantial absence of electrolyte such as sodium chloride, sodium sulphate, sodium hydroxide, potassium chloride, sodium acetate, sodium phosphates and triethanolamine sulphate, chloride and acetate, the pure middle phase region of the anionic synthetic detergents and of mixtures of these with soaps is said in most cases to be found between about 40-50 per cent and about 85-90 per cent total detergent content, the remainder of the composition being water The water-soluble soap which may be present in the detergent composition may be potassium and lower alkylolamine oleates, linoleates, laurates and caprates; also potassium and lower alkylolamine soaps of the mixed fatty acids of oils of the coconut oil group (e.g. coconut, palm kernel and babassu).  Data are given for suitable ranges of synthetic detergent to soap weight ratios and approximate limits of total detergent content for the pure middle phase region in water-detergent systems containing specified synthetic detergents and soaps.  The total detergent content of the compositions of the invention is said to be usually more than 35 per cent and seldom over 80 per cent.  The compositions may contain finely divided titanium dioxide or zinc stearate or a crystalline solid such as stearic acid or glyceryl monostearate.  Modifying ingredients such as glycerin, ethanol, soluble cellulose derivatives or deodorized kerosine may also be added.  Free fatty alcohols such as mixed coconut oil alcohols may be added to the detergent to convert some of the middle phase to neat phase or alternatively free triethanolamine may be added to prevent the formation of the neat phase.  Electrolyte may be added to convert some of the middle phase to the nigre phase dispersed throughout the middle phase.  The soap, synthetic detergent and water components of the compositions may be mixed at elevated temperatures, e.g. 130-160 DEG F. at which the mass is in the nigre phase and then cooled to room temperature.  If the composition is undesirably firm, either water or electrolyte may be added very slowly with slow agitation until the desired consistency is reached.  In an example 20 parts by weight of triethanolamine salts of sulphated coconut oil fatty alcohol, containing 2 parts of trethanolamine sulphate and chloride and unsulphated fatty alcohols, 10 parts of triethanolamine oleate, 10 parts of triethanolamine coconut oil fatty acid soaps, 2 parts of glyceryl monostearate, 1 part of coconut oil free fatty alcohols and 55 parts of water are mixed at about 130-150 DEG F. and cooled to room temperature to form an opaque paste.  Other examples are given of the preparation by similar methods of detergent compositions of varying formulae including some in which all or part of the triethanolamine detergent salts and/or soaps are replaced by the corresponding sodium soaps. Methods are given for the recognition of the presence of neat phase or nigre phase in the compositions.