Aqueous dispersions, process for their production, and their use
AssigneeDegussa AG
InventorsWolfgang Lortz, Christoph Batz-Sohn, Gabriele Perlet, Werner Will
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Abstract
An aqueous dispersion containing a cerium oxide-doped, pyrogenically produced silicon dioxide, wherein the cerium oxide is introduced through an aerosol of a cerium salt solution or suspension and the average particle size in the dispersion is less than 100 nm. The dispersion is produced by dispersing the cerium oxide-doped, pyrogenically produced silicon dioxide in aqueous solution by means of a high energy input. The aqueous dispersion can be used for chemical-mechanical polishing.
Claims28
An aqueous dispersion comprising cerium oxide-doped, pyrogenically produced silicon dioxide particles, wherein the cerium oxide is homogeneously introduced through an aerosol of cerium salt solution or suspension into a gaseous mixture obtained from the flame oxidation or flame hydrolysis of a volatile silicon compound and the resulting cerium oxide-doped silicon dioxide has an average particle size in the dispersion of less than 100 nm.
An aqueous dispersion comprising cerium oxide-doped pyrogenically produced silicon, wherein the cerium oxide is in the form of a solution or suspension and is homogeneously mixed as an aerosol with a gaseous mixture obtained from flame oxidation or flame hydrolysis of a volatile silicon compound and allowed to react in a flame, wherein the cerium oxide-doped silicon dioxide has an average particle size in the dispersion of less than 100 nm.
An aqueous dispersion comprising a cerium oxide-doped pyrogenically produced silicon dioxide, wherein the cerium oxide as a dopant is introduced through an aerosol of cerium salt solution or suspension and the average cerium oxide doped silicon dioxide has a particle size in the dispersion of less than 100 nm, and where the cerium oxide dopant does not become detached as the dispersion is prepared using a high pressure homogenizer.
An aqueous dispersion comprising water and cerium oxide-doped, pyrogenically produced silicon dioxide particles, wherein the said particles are produced by introducing an aerosol of cerium salt solution or suspension into a gaseous mixture obtained from the flame oxidation or flame hydrolysis of a volatile silicon compound, said dispersion having been produced by subjecting said cerium oxide doped silicon dioxide particles to pressure of up to 3500 kg/cm2 and expanding said particles through a nozzle thereby causing said particles to collide with one another or against a wall to thereby obtain a dispersion wherein said particles in said dispersion have an average particle size of less than 100 nm.
Dependencies are inferred from the claim text.