Dispersion of aluminium oxide

US7572854B2 · kind B2 · utility

Assignee

• Degussa AG · DE

Inventors

• Gerrit Schneider · Hanau, DE
• Heinz Lach · Rodenbach, DE
• Thomas Scharfe · Alzenau, DE

Key dates

• Filing date: Oct 22, 2002
• Grant date: Aug 11, 2009
• Expiry date: Oct 22, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31993
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Aqueous dispersions of a pyrogenically-produced aluminum oxide are prepared form a mixture containing water, additives and a high-surface-area pyrogenically-produced aluminum oxide with a BET specific surface area of more than 115 m2/g and a Sears number of more than 8 ml/2 g using controlled high shearing conditions. Prior to subjecting the mixture to high shear conditions, the pH of the mixture is adjusted to a value between of 2 to 11 (preferably 3 to 8). The aqueous dispersion has a mean particle size distribution of d50<150 nm. These dispersions are useful in the production of Inkjet media, digital imaging products and other printing media and result in high color densities, photo-realistic reproductions and particularly good print and gloss quality.