Patent GB-672837-A (GB)
Title: A product for the treatment of keratinous fibres and a process for making the said product
IPC: D06M13/252
Filed: 1950-04-21
Abstract: Water-soluble salts of organic thiosulphuric acids of formula RSSO3H wherein R is an organic radical are used together with water-soluble mercaptans in the treatment of keratinous materials, the molar ratio of mercaptan to organic thiosulphate being greater than 1 : 1 (see Group IV (c)).  The group R may be alkyl, amino-alkyl, carboxyalkyl, amino-carboxyalkyl, hydroxyalkyl, hydroxyalkoxyalkyl, aryl, alkylaryl, or cycloaliphatic.  Example 1 describes the preparation of glyceryl thiosulphate by heating together in aqueous solution equimolecular quantities of glycerin-a -monochlorhydrin and hydrated sodium thiosulphate (Na2S2O3.5H2O).  Mixtures of mercaptans and salts of organic thiosulphuric acids may be prepared by reducing a water-soluble organic disulphide with a water soluble sulphite, bisulphite or hydrosulphite.  The disulphide may be prepared if desired by oxidation of a mercaptan in aqueous solution with hydrogen peroxide until no colour is produced with sodium nitroprusside. Reference is made to the following mercaptans: thioglycollic acid, thioglycerol, ethyl mercaptan, benzyl mercaptan, mercapto ethyl sulphonic acid, b -amino ethyl mercaptan, b -mercapto ethyl methylamine, b -mercaptoethyl dimethylamine, b -mercapto ethyl alcohol, mercapto carbinol, mercapto acetaldehyde, mercapto dimethyl ketone, mercapto ethyl acetate, b -mercapto diethyl ether, 3-amino-2-hydroxy propyl mercaptan, trithiohexitols, mono- and poly-thiopolyoxyethylene glycols (such as tetraglycol dimercaptan) mercapto ethyl hydroxy ethylamine, monothiopoly hydroxyacids such as mono-thio-mucic acid and thiocitric-acid, mono- and di-mercapto succinic acids, thiocitric acid, mercaptoamino acids, a -mercaptomethyl-furane, -pyrrole, -thiophene and -pyrimidine, thiofurfuralcohol, mercapto alkyl pseudothioureas, mercapto ethyl urethane, mercapto ethyl acetamide, mercapto ethyl guanidine, mercapto alkyl betaines and mercapto-taurines.  Reference is made also to the following disulphides: dithiodiglycerol, dithiodiethanol, dithiodipropanol, disulphide of 2-mercapto-1-propanol, dithiodierythritol, dithiodiarabitol, dithiodisorbitol, disulphide of 2-mercapto sorbitol, a ,a 1-dimethyl-dithiodiglycerol, disulphide of 3-mercapto-1,2-butanediol, disulphide of 1-mercapto - 2,4 - hydroxypentane, dithioditetraethylene glycol, ethanol glycerol disulphide, diethylene glycol sorbitol disulphide, the disulphide of thioglycollic acid and the disulphide of benzyl mercaptan.  As the reducing agent, sodium sulphite, bisulphite or hydrosulphite may be employed.  Other reducing agents include potassium hydrosulphite and bisulphite, the corresponding ammonium and substituted ammonium and amine salts such as ammonium and monoethanolamine hydrosulphite and sulphite.  The term "hydrosulphite" includes hydrosulphites containing formaldehyde of crystallization (sulphoxylates).  1-2 mols. of reducing agent per mol. of disulphide is preferred, though quantities from 1/8 -10 mols. may be used.  In example 2, 75 parts (by weight) of an 8 per cent solution of thioglycerol are made alkaline with ammonia and carefully oxidized with 15 per cent hydrogen peroxide to give dithiodiglycerol; 6 parts of sodium hydrosulphite are added and the mixture allowed to stand, giving a reaction product comprising glyceryl thiosulphate and thioglycerol, the latter being in molar excess.  Further examples describe (4) the reaction between dithiodiethanol and sodium hydrosulphite, or (5) between dithiodipropanol and sodium hydrosulphite; (6) the oxidation of thiosorbitol to dithiosorbitol and subsequent reduction with sodium hydrosulphite; (7) the oxidation of a mixture of mercapto ethanol and thioglycerol to give dithiodiethanol, dithiodiglycerol, and ethanol glycerol disulphide, which mixture is subsequently reduced with sodium hydrosulphite, and (10) the controlled oxidation of an aqueous alkaline solution of thioglycollic acid whereby part only is oxidized to the disulphide, which is subsequently reduced with ammonium bisulphite.  Specification 672,838 is referred to.ALSO:A composition for the treatment of keratinous materials comprises a water-soluble mercaptan and a water-soluble salt of an organic thiosulphuric acid of the formula RSSO3H, wherein R is an organic radical, the molar ratio of mercaptan to thiosulphate being greater than 1 : 1.  Specified mercaptans are thioglycollic acid, thioglycerol, ethyl mercaptan, benzyl mercaptan, mercapto ethyl sulphonic acid, b -amino ethyl mercaptan, b -mercapto-ethyl methylamine, b -mercapto-ethyl dimethylamine, b -mercapto ethyl alcohol, mercapto carbinol, mercapto acetaldehyde, mercapto dimethyl ketone, mercapto ethyl acetate, b -mercapto diethyl ether, 3-amino-2-hydroxy propyl mercaptan, trithiohexitols, mono- and poly-thiopolyoxyethylene glycols (such as tetraglycol dimercaptan), mercapto-ethyl hydroxy ethylamine, monothiopolyhydroxy acids such as monothiomucic acid and thiocitric acid, mono- and di-mercapto succinic acid, mercaptoamino acids, a -mercapto methyl-furane, -thiophene, -pyrrole and -pyrimidine, thiofurfuralcohol, mercapto alkyl pseudothioureas, mercapto ethyl urethane, mercapto ethyl acetamide, mercapto ethyl guanidine, mercapto alkyl betaines and mercapto taurines.  It is essential that the organic thiosulphate should be soluble in the mercaptan solution.  The group R may be alkyl, amino-alkyl, carboxy-alkyl, amino-carboxy-alkyl, hydroxy-alkyl, hydroxyalkoxy-alkyl, aryl, alkyl-aryl or cycloaliphatic.  The compositions are used in aqueous solution at pH 7-10.5, the concentration of mercaptan being from 1/4 to 15 per cent (preferably 3-8 per cent) by weight.  In making the compositions, the two components may be mixed, or a water-soluble organic disulphide may be reduced by a water-soluble hydrosulphite, bisulphite or sulphite to give a mixture of mercaptan and organic thiosulphate, to which additional mercaptan may be added, if necessary, or a mercaptan may be subjected to controlled oxidation in aqueous alkaline solution whereby part only is oxidized to disulphide, which in its turn may be reduced by a water-soluble sulphite, bisulphite or hydrosulphite to form organic thiosulphate and additional mercaptan (see Group IV (b)). The reducing action of hydrosulphite on a disulphide produces a p  mixture in which the molar percentage of mercaptan predominates, but that of sulphite and bisulphite gives equimolar proportions of mercaptan and thiosulphate.  Specified disulphides which may be used are dithiodiglycerol, dithiodiethanol, dithiodipropanol, disulphide of 2-mercapto-1-propanol, dithiodierythritol, dithiodiarabitol, dithiodisorbitol, disulphide of 2 - mercapto - sorbitol, a ,a 1-dimethyldithiodiglycerol, disulphide of 3-mercapto-1,2-butanediol, disulphide of 1-mercapto-2,4-dihydroxy-pentane, dithioditetraethylene glycol, ethanol glycerol disulphide, diethylene glycol sorbitol disulphide, the disulphide of thioglycollic acid and the disulphide of benzyl mercaptan.  As the reducing agent, sodium hydrosulphite, bisulphite and sulphite may be employed.  Other reducing-agents include potassium hydrosulphite and bisulphite, and the corresponding ammonium and substituted ammonium and amine salts such as ammonium and monoethanolamine hydrosulphite and sulphite.  The term "hydrosulphite" includes hydrosulphites containing formaldehyde of crystallization (sulphoxylates).  The alkalinity of the composition may be adjusted with ammonia, methylamine, ethylamine, monoethanolamine, morpholine or water-soluble quaternary ammonium bases such as tetraethyl - ammonium hydroxide or tetraethanolammonium hydroxide.  Alkali hydroxides, bicarbonates and carbonates may also be used provided that the maximum alkalinity is not greater than 10.5, buffers such as ammonium acetate, diammonium phosphate, ammonium carbonate and borax being employed to prevent this.  After the keratin containing materials have been softened, they may be rinsed and fixed by use of chlorine water, hydrogen peroxide, tartaric acid, sodium chlorite or potassium bromate as known in the art.  Hair or wool may be treated.  In an example, equimolar quantities of glycerine-a -monochlorhydrin and hydrated sodium thiosulphate (Na2S2O3.5H2O) are heated together in aqueous solution to give a solution containing glyceryl thiosulphate and sodium chloride.  12.4 parts by weight of this solution, 6.0 parts by weight of thioglycerol and 81.6 parts by weight of water containing sufficient ammonium hydroxide to bring the pH to 9.3 are mixed and the solution used for waving human hair, 1 per cent sodium chlorite being used to fix the curl. Further examples describe the procedure using (2) dithiodiglycerol and sodium hydrosulphite; (4) dithioethanol and sodium hydrosulphite; (5) dithiopropanol and sodium hydrosulphite; (6) dithiosorbitol and sodium hydrosulphite; (7) a mixture of dithiodiglycerol, dithiodiethanol and ethanol glycerol disulphide and sodium hydrosulphite; and (10) the product of the controlled partial oxidation of thioglycollic acid to dithiodiglycollic acid and its subsequent reduction with ammonium bisulphite. Specification 672,838 is referred to.