Silicon-aluminum mixed oxide

US6455455B1 · kind B1 · utility

Assignee

• Degussa AG · DE

Inventors

• Klaus Deller · Großkrotzenburg, DE
• Rainer Golchert · Darmstadt, DE
• Dieter Kerner · Midland Park, US
• Helmut Mangold · Rodenbach, DE

Key dates

• Filing date: Apr 28, 2000
• Grant date: Sep 24, 2002
• Expiry date: Apr 28, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/22
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A silicon-aluminum mixed oxide produced by flame hydrolysis and having a composition of from 1 to 99.999 wt. % Al2O3, the remainder being SiO2, which mixed oxide exhibits an amorphous structure in the X-ray diffraction pattern and consists of intergrown primary particles, and in these primary particles crystallites are present. These crystallites having sizes of between one and 200 namometers and the specific surface of the powder being between 5 and 300 m2/g. These products are produced by a process wherein silicon halide and aluminum halide are vaporized in a particular ratio to one another and are homogeneously mixed with air, oxygen and hydrogen in a mixing unit by means of any carrier gas, this mixture undergoes combustion in a burner of known construction and, after the separation of the solids from the vapour phase, any traces of halide possibly adhering to the product are separated off in a further processing step by means of moist air at elevated temperature. The silicon-aluminum mixed oxide produced by flame hydrolysis are used in the form of dispersions for polishing, in particular in the electronics industry (CMP).