Patent ID: 6770613
Filing Date: 2004-08-03
Classification: C11D

Abstract:
A process for preparing a non-Newtonian substantially anhydrous surfactant paste containing less than 5% water, comprising the steps of:A) forming an aqueous surfactant mixture by blending, by weight of the mixture: (a) from about 5% to about 85% of an anionic surfactant; (b) from about 5% to about 95% of a liquid nonionic surfactant; (c) from about 1% to about 40% of a hydrotrope, said hydrotrope comprising at least two polar groups separated from each other by at least 5 carbon atoms; wherein the aqueous surfactant mixture has a water content from 5% to about 80% by weight of the aqueous surfactant mixture;B) drying the aqueous surfactant mixture under vacuum to form said substantially anhydrous surfactant paste having a water content of less than 5%, said paste being in the form of a shear-thinning non-Newtonian fluid having a yield value less than about 200 Pa at 30Â° C.; and C) optionally, adding an anhydrous organic liquid to the surfactant paste from step B to facilitate handling and transportation.