摘要 |
<p>High-viscosity aqueous emulsions of functional alkoxysilanes, condensed oligomers thereof, organopolysiloxanes, their preparation and use for the surface treatment of inorganic materials High-viscosity aqueous oil-in-water emulsion which comprises from 50 to 90% by weight, based on the total weight of the emulsion, of functional alkoxysilanes and/or condensed oligomers thereof and/or organoalkoxysiloxanes, at least one emulsifier and water and has a pH of from 5 to 9 and a mean droplet size of the disperse phase of less than 5 μm, wherein the width of the droplet size distribution, expressed as the span (see formula (I)), is >1.5, preferably from 3 to 8. The preparation of the emulsions having the desired droplet size distribution is carried out in apparatuses having at least one pressure stage at a pressure of from 2 to 15 MPa. The emulsion can be used for hydrophobicizing porous mineral building materials. D 90 - D 10 D 50 ( I )</p> |