Verfahren zur Herstellung von Silica-haltigen Polyol-Dispersionen und deren Verwendung zur Herstellung von Polyurethanwerkstoffen

The invention relates to a method for producing polyols containing silicate, comprising the steps of (i) mixing an aqueous silica sol (K) having an average particle diameter of I to 150 nm with a content of silicic acid, calculated as SiO2, from I to 60 wt % at a pH of I to 6, relative to the content of SiO2 used, and 0.1 to 20 times the amount, relative to water, of at least one organic solvent (L) selected from the group comprising methanol, ethanol, l-propanol, 2-propanol, l-butanol, 2-butanol, 2-me­ thyl-2-propanol, l-chloro-2-propanol, cyclopentanol, cyclohexanol, l,4-dioxane, tetrahydrofuran, l-methoxy-2-propanol, l­ ethoxy-2-propanol, 2-ethoxyethanol, 2-methyl-2-propanol, 2-methoxyethanol, dimethylformamide, acetonitrile, dimethyl sulfoxi­ de, acetone, methyl ethyl ketone, and ethyl acetate, and (ii) mixing the mixture thus obtained with a polyol, (iii) at least partially distilling off the organic solvent (L) and water, (iv) mixing with at least one compound (S) comprising at least one at least mono­ alkoxylated silyl group and at least one alkyl, cycloalkyl, or aryl substituent which can contain heteroatoms, wherein said substitu­ent optionally comprises a group which is reactive with an alcohol, an amine, or an isocyanate at an amount of0.l to 20 µmol (S) per m2 surface of (K), wherein the steps (i), (ii), and (iv) can be performed simultaneously or consecutively in any sequence, (v)optionally adjusting the pH of the polyol containing silicate to a value of 7 to 12 by adding a strongly basic compound, wherein the step (v) can also be performed between the steps (iii) and (iv).