GB995633A - Detergent compositions - Google Patents

Abstract

Dry compositions containing hydrated sodium tripolyphosphate are produced by preparing an aqueous slurry of the tripolyphosphate, of which at least part, generally at least 50% and preferably at least 70%, consists of the Form I modification, at above 75 DEG C., preferably at 85-110 DEG C., the amount of water used being more than sufficient to hydrate the Form I tripolyphosphate present, holding the slurry at above 75 DEG C. until at least a substantial proportion of the tripolyphosphate has become hydrated, and then heat-drying the slurry, e.g. by spray-drying. Form II tripolyphosphate may also be included in the slurry, and is suitably added while the slurry is being held above 75 DEG C. prior to drying. Detergent compositions may be obtained by including anionic or nonionic surface-active agents in the slurry (see Division C5).ALSO:Dry detergent compositions are produced by preparing an aqueous slurry of sodium tripolyphosphate of which at least part, generally at least 50% and preferably at least 70%, consists of the Form I modification, and an anionic or non-ionic detergent at a temperature above 75 DEG C. but preferably in the range 85-110 DEG C., the amount of water used being more than sufficient to hydrate the Form I trioplyphosphate present, holding the slurry at above 75 DEG C. until at least a substantial proportion of the tripolyphosphate has become hydrated and then heat-drying the slurry, e.g. by spray-drying. Suitable detergents are alkali metal soaps, alkylaryl sulphonates, e.g. sodium dodecyl benzene sulphonate, alkyl sulphates, alkylthio sulphates; ethylene or propylene oxide condensates with glycerol, arylamines, tall oil and fatty alcohols, acids, amines and mercaptans; and fatty acid methanolamides, ethanolamides or propanolamides. The detergent usually comprises 5-35%, preferably 10-22%, by weight of the final dry mixture. Sodium sulphate, silicate (Na2O:SiO2 = 1:2.5), pyrophosphate and Form II-tripolyphosphate may also be included, any form II-tripolyphosphate generally being added while the prepared slurry is being held above 75 DEG C. prior to heat-drying.