Silicon dioxide dispersion comprising polyol

US8911638B2 · kind B2 · utility

Assignee

• Degussa AG · DE

Inventors

• Wolfgang Lortz · Wächtersbach, DE
• Christoph Batz-Sohn · Hanau, DE
• Helmut Mangold · Rodenbach, DE
• Gabriele Perlet · Großkrotzenburg, DE
• Werner Will · Gelnhausen, DE
• Sascha Reitz · Hanau, DE

Key dates

• Filing date: Jun 16, 2005
• Grant date: Dec 16, 2014
• Expiry date: Mar 25, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/22
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Stable, pourable silicon dioxide dispersion, in which the average, number-related aggregate diameter of the silicon dioxide particles in dispersion is less than 200 nm, and which comprises at least 35 wt. % of a silicon dioxide powder, 3 to 35 wt. % of at least one polyol, 20 to 60 wt. % of water, 0 to 10 wt. % of an additive and a substance having an alkaline action in an amount such that a pH of 10<pH<12 is established. It can be prepared by a procedure in which silicon dioxide powder is introduced into water and a polyol in a rotor/stator machine, the pH being less than 5, and the mixture is dispersed until the current uptake of the rotor/stator machine is largely constant, and a substance having an alkaline action is subsequently added in an amount such that a pH of the dispersion of 10<pH<12 results, the substance having an alkaline reaction being added so rapidly that no gel formation takes place. It can be used as a component of a flame-retardant filling of hollow spaces between building components, in particular for insulating glass arrangements.