Prepn. of highly structured finely divided silica - from alkali silicate solns. with addn. of mixts. of cationic and nonionic surfactants

摘要

Prepn. of highly structured finely divided silica comprises reaction of alkali silicate soln. with acid or acid-type reagents with mixing by stirring and temporary action of high shear strengths. Solns. of mixts. of cationic and nonionic surfactants are added prior to reaching an electrolyte concn. of 0.3N. The concn. of these solns. is such that coagulation takes place below the critical micelle-forming concn. of the surfactant mixt. USE/ADVANTAGE - Finely divided silica is a filler for polymer work-up, a thickener and thixotropic agent for various systems, a carrier for biological active agents, an extender for dispersion paints and a mobile solvent for bulk materials. The process is economical and pptn. is easier to control than with prior art processe