Patent GB-628458-A (GB)
Title: Improvements in or relating to method of soap making and the product resulting therefrom
IPC: C11D13/02
Filed: 1944-11-27
Abstract: Soap is prepared by reacting an alkali at a temperature of 20 DEG  to 100 DEG  C. with the synthetic fatty acids prepared by the process of Specification 628,457, [Group IV (b)].  The synthetic fatty acids may be used alone or mixed with other fatty acids, fats and fatty oils. Saponification with an alkali carbonate solution yields white odourless soap, whereas saponification with alkali hydroxide solution yields soap having the colour and odour of rosin soap.  But if the saponification with alkali hydroxide is carried out in the presence of hydrogen peroxide or of a water-soluble oxidizing salt, such as an alkali perborate, an alkali bisulphite, or an alkali persulphate as a protective agent, odourless white or cream-coloured soap may be obtained.  Where the soap is prepared from a mixture of fatty acids and fat or fatty oil, the mixture may first be treated with alkali carbonate solution to neutralize the fatty acids present, and the mixture further reacted at elevated temperature, if necessary with alkali hydroxide, to saponify the fat or fatty oil.  After saponification, any of the usual soap builders and fillers may be crutched into the soap, if desired, as well as any perfume or colouring matter.  Fillers mentioned are perborates, silicates, pyrophosphates, potassium chloride, sodium chloride, potash, borax and sodium carbonate.  Alternatively, fillers may be incorporated into the soap mass by adding them to the aqueous solution of protective agent which is added before saponification.  In the examples, the synthetic fatty acids of Specification 628,457, either alone or mixed with beef tallow, olein, soya bean oil, peanut oil, olive oil, olive oil foots, sesame oil, linseed oil, stearic acid, tallow fatty acids or rosin, are saponified, if desired in the presence of sodium perborate or borax, with sodium or potassium carbonate, sodium or potassium hydroxide, or both alkali metal hydroxide and alkali metal carbonate.  Filler mixtures mentioned in the examples are (a) sodium silicate, with sodium or potassium carbonate, and sodium perborate or borax, with or without sodium pyrophosphate, and (b) potassium silicate with potassium carbonate and potassium chloride.ALSO:Soap is prepared by reacting an alkali at a temperature of 20 DEG  to 100 DEG  C. with the synthetic fatty acids prepared by the process of Specification 628,457. Water-insoluble soaps may be obtained by reacting a solution of the alkali metal soap thus obtained with a multivalent metal salt capable of forming a water-insoluble soap, and recovering and washing the thus precipitated insoluble soap.  In an example, the alkali metal soap solution is reacted with manganese sulphate solution.  Other water-soluble metal salts may be substituted for manganese sulphate, exemplary materials being the manganese, alkaline earth, magnesium, aluminium and heavy metal water-soluble salts of mineral or organic acids, such as the chlorides, sulphates, nitrates and acetates.  The Specification includes an additional example of the process of preparing synthetic fatty acids according to the process of Specification 628,457.