METHOD FOR PRODUCING SILICA-CONTAINING DISPERSIONS CONTAINING POLYETHEROLS OR POLYETHERAMINES

摘要

Method for producing silica-containing dispersions containing a polyetherol or a polyetheramine, comprising the steps (i) admixing an aqueous silica sol (K) having a median particle diameter of 1 to 150 nm having a silica content, calculated as SiO2, of 1 to 60% by weight having a pH of 1 to 6 with at least one polyetherol (b1) and/or polyetheramine (b2) based on ethylene oxide and/or propylene oxide having a median OH- or amine functionality of 2 to 6 and a number-average molecular weight of 62 to 6000 g/mol, (ii) at least partially distilling off the water, (iii) admixing the dispersion with at least one compound (S) that comprises at least one at least monoalkoxylated silyl group and at least one alkyl, cycloalkyl or aryl substituent, wherein this substituent can optionally comprise groups that are reactive to an alcohol, an amine or an isocyanate, in an amount of 0.1 to 20 µmol (S) per m2 of surface area of (K), wherein the steps (i) and (iii) can be carried out simultaneously or in any sequence one after the other, (iv) optionally setting the pH of the resultant silica-containing dispersions to a pH of 7 to 12 by adding a basic compound, wherein the step (iv) can alternatively be carried out between steps (ii) and (iii).