Aqueous dispersions of organosilicon compounds

摘要

Stable aqueous organosilicon dispersions particularly useful for the hydrophobing of construction materials are prepared by first preparing a homogenous mixture of organopolysiloxanes and hydrophobic silica filler, and dispersing this mixture together with an alkylalkoxysilane bearing at least one C4 or greater alkyl group into water.

主权项

1. An aqueous dispersion of organosilicon compounds, comprising:
(A) a mixture consisting essentially of inorganic filler (B) and siloxane (C) containing units of the formula (I)
Ra(R1O)bSiO(4-a-b)/2  (I) in which R are the same or different and are hydrogen or a monovalent, SiC-bonded, optionally substituted hydrocarbyl radical, R1 are the same or different and are hydrogen, or a monovalent, optionally substituted hydrocarbyl radical, a is 0, 1, 2 or 3, and b is 0, 1, 2 or 3, with the proviso that the sum of a and b is less than or equal to 3, and the siloxane (C) has a viscosity at 25° C. of 5 to 1,000,000 mPas, the mixture (A) having a viscosity of 10 to 10,000,000 mPas at 25° C., and filler (B) comprising silica, (D) silanes of the formula
R3cR2dSi(OR4)4-c-d  (II) in which R2 are the same or different and denote monovalent, SiC-bonded, optionally substituted hydrocarbyl radicals having 1 to 3 carbon atoms, R3 are the same or different and denote monovalent, SiC-bonded, optionally substituted hydrocarbyl radicals having at least 4 carbon atoms, which may be interrupted by heteroatoms and/or carbonyl groups, R4 are the same or different and denote monovalent, optionally substituted hydrocarbyl radicals or hydrogen, c is 1, 2 or 3, and d is 0, 1 or 2, with the proviso that the sum of c and d is 1, 2 or 3, and/or partial hydrolysates thereof, (E) optionally organopolysiloxanes, (F) emulsifier, (G) water, and (H) optionally further substances.