GB1151767A - Process for the preparation of Detergent Compositions - Google Patents

Abstract

1,151,767. Low bulk density detergents. COLGATE-PALMOLIVE CO. 2 June, 1966 [24 June, 1965], No. 51970/68. Divided out of 1,151,766. Heading C5D. A continuous process for the production of a detergent composition of low bulk density comprises forming an aqueous slurry containing an organic detergent, adding to the slurry or forming therein an inorganic alkali metal or alkaline earth metal, alkaline or neutral detergent builder salt, mixing the slurry in the presence of the builder salt and of a normally gaseous substance under conditions that impart a high shear and under superatmospheric pressure to disperse the gaseous substance uniformly therein terminating the mixing, and reducing the pressure to atmospheric pressure. The builder salt is preferably a hydratable material or a substance capable of forming a hydratable material such as an alkali metal or alkaline earth metal phosphate, sodium carbonate, sodium silicate, magnesium sulphate or sodium tetraborate. The builder salt may be formed in situ by commingling with the slurry a caustic alkali and a substance capable of reacting with water in the presence of the caustic alkali to produce a water-soluble alkali metal polyphosphate hydrate, suitably the additive is an alkali metal trimetaphosphate. The detergent used may be anionic, for example a water-soluble soap, an alkyl aryl sulphonate, an alkyl sulphate or sulphonate, a fatty acid ethanolamide sulphate, a fatty acid amide of an aminoalkyl sulphonic acid, or a fatty acid ester of isethionic acid. The surfactant may be wholly or partially nonionic, the nonionics used include polyalkylene oxide condensates with alkyl phenols, alkanols, fatty acid amides or with polyoxypropylene glycols. Cationic or amphalytic detergents may also be included in the composition. The gaseous substance is most suitably air, but may be nitrogen, oxygen or carbon dioxide. The process may be operated so that the slurry is continuously and automatically metered to a point where the builder salt (or a substance capable of forming the same) is added in an automatically controlled and continuously metered amount; and the slurry has such a high solids content as to be difficultly flowable, i.e. the solids content is in excess of 70% in the high shear mixing step. Preferably, the slurry is mixed in the presence of the normally gaseous substance for a period of up to 30 seconds, at a pressure of 20 p.s.i.g. and with a shear factor in excess of 5; so that the gaseous substance is dispersed throughout the slurry as discrete bubbles, the majority of which have an average diameter of less than 0À054 mm.