GB916570A - Improvements in or relating to soap - Google Patents

Abstract

Filamentary growth is produced on the surface of water-containing soap objects, e.g. having the form of animals or human beings, by applying thereto a thin layer (preferably less than 2m thick) of a sol, a suspension, or a gel, or a solution of a gel-forming substance, drying the layer, and then exposing the object to the air; it is preferred that the water content of the soap object be greater than 10% and that the soap consists partly of sodium oleate. Colloids which are suitable for direct application are (a) silicic acid in the form of a 4-8% gel suspension, (b) magnesium, aluminium, ferric, chromic or manganese hydroxides in the form of a 0,3-1,5% gel suspension, (c) silicates of these metals or of zinc in the form of a 0,3-0,6% gel suspension, (d) alginic acid or cellulose glycollic acid in the form of a 1-2% gel suspension, and (e) Prussian blue in the form of a 1,5-3% gel suspension. Solutions of gelforming substances which are suitable are solutions of sodium aluminate, alginate and cellulose glycollate; objects which have been coated therewith are treated with carbon dioxide whereby the free colloidol substance is formed. In a modification, the sol, suspension, or gel, or the solution of the gel-forming substance is incorporated in the body of the soap; under these conditions, the preferred amounts of the colloids above are (a) 6-10%, (b) 0,6-3% and (c) 0,3-1,5%. Silica and iron, titanium and aluminium oxides in the form of aerogels are also suitable colloids for this embodiment. The objects are preferably dried and exposed to air having a relative humidity 10-20% below that at which the soap neither increases nor decreases in weight, most suitably at a relative humidity of 70-80%. If desired, the filamentary growth may be inhibited over selected areas of the objects to produce a patterned or decorative effect, by coating these areas with a 2-10% aqueous solution of polyvinyl alcohol or pyrrolidone, a polymethacrylate, gelatin, or varnishes containing nitrocellulose or chlorinated rubber. The colourless filaments may be dyed, e.g. with petroleum ether solutions of eosin or Sudan red, and then either rendered insoluble by immersion in calcium or barium chloride solution, or fixed by spraying with an alcoholic solution of shellac or with an aqueous solution of polyvinyl alcohol.