| 摘要 |
Process for producing silica-comprising dispersions comprising a polyetherol or a polyether amine, which comprises the steps of (i) admixing an aqueous silica sol (K) having an average particle diameter of from 1 to 150 nm and a silica content, calculated as SiO2, of from 1 to 60% by weight and a pH of from 1 to 6 with at least one polyetherol (b1) and/or polyether amine (b2) based on ethylene oxide and/or propylene oxide and having an average OH or amine functionality of from 2 to 6 and a number average molecular weight of from 62 to 6000 g/mol, (ii) distilling off at least part of the water, (iii) admixing the dispersion with at least one compound (S) having at least one at least monoalkoxylated silyl group and at least one alkyl, cycloalkyl or aryl substituent, where this substituent may have groups which are reactive toward an alcohol, an amine or an isocyanate in an amount of from 0.1 to 20 μmol of (S) per m2 of surface area of (K), where steps (i) and (iii) can be carried out simultaneously or in succession in any order, (iv) optionally adjusting the pH of the silica-comprising dispersions obtained to a value of from 7 to 12 by adding a basic compound, where step (iv) can also be carried out between steps (ii) and (iii). |
