Patent ID: 7645335

Claim:
An aqueous dispersion comprising hydrophobized silicon dioxide powder, wherein the content of hydrophobized silicon dioxide powder is between 5 and 50 wt. % and the dispersion comprises at least one compound of the general formula R 1 —COO—(CH 2 —CH(Ph)—O) a —(C n H 2n-x R 2 x —O) b —R 3 (I) wherein R 1 is hydrogen, a linear or branched, saturated or unsaturated alkyl chain having 1 and up to 29 carbon atoms, a phenyl radical, an alkyl-substituted phenyl radical having up to ten carbon atoms in the alkyl radical, R 2 is an alkyl radical having 1 to 5 C atoms, R 3 is hydrogen, an alkyl chain having 1 and up to 18 carbon atoms, a benzyl radical, an alkyl-substituted benzyl radical having up to four carbon atoms in the alkyl radical, a C(O)R 5 group with a radical R 5 which contains an alkyl chain having 1 to 18 carbon atoms, a C(O)NHR 6 group with a radical R 6 which contains a hydrogen atom or an alkyl chain having 1 to 18 carbon atoms, —C(O)OR 7 , which contains an alkyl chain R 7 having 1 to 18 carbon atoms, Ph is a phenyl derivative with the general formula —(C 6 H 5-y R 4 y )—, wherein R 4 is a hydroxyl radical, an alkyl radical having 1 to 6 carbon atoms or an alkoxy radical having 1 to 6 carbon atoms, and y is a number from 0 to 5, a is 0 to 5, b is 10 to 150, n is 2 to 4, x is 0 or 1, wherein the compound is present in an amount sufficient to inhibit separation of the dispersion for at least 30 days.