The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 2004
Filed:
Aug. 29, 2001
Jürgen Schubert, Wachtberg, DE;
Klaus-Dieter Hellwig, Bad Honnef, DE;
Astrid Muller, Mömbris, DE;
Degussa AG, Duesseldorf, DE;
Abstract
Aluminum-doped precipitated silicas having a BET surface area of more than 300 m /g and aluminum distributed uniformly in the silica particles are prepared by sequentially heating a mixture of water and sodium silicate at a temperature of from 70 to 86° C. and adding sulfuric acid until half of the sodium silicate is neutralized, then aging the mixture for a time of from 30 to 120 minutes, adjusting the pH of the mixture with sulfuric acid to a range of from 3.0 to 7.0, thereby precipitating the aluminum-doped silica, filtering the aluminum-doped silica from the mixture to form a filtercake and washing the filtercake, followed by drying and/or grinding the washed filtercake. An aluminum salt solution is metered into the mixture at step a) and/or step c). The aluminum-doped precipitated silicas of the present invention may be used in coatings for paper and other media intended for ink jet printing.