Dispersion and method for modifying a surface with hydrophobized silica

摘要

A dispersion, comprising 0.1 to 25% by weight hydrophobized silica, 8 to 90 wt % of at least one alcohol selected from the group consisting of ethanol, 1-propanol and 2-propanol, 7 to 89 wt % of water, 0 to 30% by weight solvent immiscible with water, and 0.04 to 5 wt % of at least one carboxyvinyl polymer present in neutralized form, can be applied to a surface using a non-drip application method and, by modifying the surface with hydrophobized silica, imparts water-repelling and self-cleaning properties to the surface.

主权项

1. A dispersion for modifying a surface with hydrophobized silica, comprising, based on the weight of the dispersion:
a) from 0.1 to 25% by weight of hydrophobized deagglomerated silica, wherein the hydrophobized deagglomerated silica in the dispersion has been prepared by comminution of particles of hydrophobized silica in a suspension comprising at least one alcohol selected from the group consisting of: ethanol; 1-propanol; and 2-propanol; and at least one silazane of formula (I) or (II):
(R1R2R3Si)2NR4  (I)cyclo(R1R2SiNR4)m,  (II)in which:the moieties R1, R2, and R3, independently of one another, are hydrocarbon moieties having from 1 to 12 carbon atoms;the moiety R4 is hydrogen or methyl; andm is from 3 to 8; b) from 8 to 90% by weight of at least one alcohol selected from the group consisting of: ethanol; 1-propanol; and 2-propanol; c) from 7 to 89% by weight of water; d) from 0 to 30% by weight of solvents not miscible with water; and e) from 0.1-0.2% by weight of at least one carboxy vinyl polymer, wherein said carboxy vinyl polymer is present in neutralized form.