GB648722A - Process for the preparation of readily foaming and strongly lathering soap - Google Patents

Abstract

Soap having little irritative effect on the skin is produced by superfatting soap by means of at least 5 per cent fatty acids calculated on the bound fatty acids. The proportion may comprise 5 to 100 and preferably 20 to 60 per cent. The superfatting may be effected by mere admixture or by adding a proportion of an acid soap (as opposed to a normal soap) to the original neutral soap, or by making the original soap from fatty acids and saponifying with an insufficient quantity of alkali, or by partly converting neutral soap by the addition of a mineral acid into free fatty acids. The superfatting is preferably applied to soaps made from the lower fatty acids or their glycerides such as coconut oil, palm kernel, babassu, cohune and other kernel oils and their fatty acids which give soaps forming an abundant lather but which, however, irritate the skin. The latter defect is reduced by the superfatting aforesaid. Still less skin irritation results if topped lower fatty acids are used to make the soaps, i.e. lower fatty acids from which the caproic, caprylic and capric acids have been removed. In order to increase the toughness of the superfatted soap and enable it to be moulded into bars, cakes, &c. a proportion of rosin, hydrogenated rosin, other derivatives of rosin or castor oil may be added to the soap prior to the saponification. The same improvement may be effected by saponifying with a mixture of sodium and potassium hydroxides. The fatty acids used for superfatting exemplified comprise coconut oil fatty acids, hydrogenated palm oil fatty acids, hydrogenated ground nut fatty acids, hydrogenated whale oil fatty acids, and stearic fatty acids.