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:
Sep. 16, 2014
Filed:
Nov. 17, 2009
Christian Schulze-isfort, Limeshain, DE;
Christoph Batz-sohn, Hanau-Mittelbuchen, DE;
Herbert Habermann, Biebergemuend, DE;
Ralph Hofmann, Buchen, DE;
Christian Schulze-Isfort, Limeshain, DE;
Christoph Batz-Sohn, Hanau-Mittelbuchen, DE;
Herbert Habermann, Biebergemuend, DE;
Ralph Hofmann, Buchen, DE;
Evonik Degussa GmbH, Essen, DE;
Abstract
Process for preparing an aluminum oxide powder which is present in the form of aggregated primary particles and comprises at least 85% by weight of alpha-aluminum oxide, in which an aluminum oxide powder which a) is present in the form of aggregated primary particles, b) is selected from the group consisting of gamma-aluminum oxide, theta-aluminum oxide, delta-aluminum oxide and/or X-ray amorphous aluminum oxide, and c) has a tamped density of at least 250 g/l, is subject to a heat treatment at 13000 C or more and subsequently milled. Aluminum oxide powder which can be obtained by this process. Aluminum oxide powder in the form of aggregated primary particles having a BET surface area of from 3 to 30 m2/g, in which the proportion of alpha-aluminum oxide is at least 85% by weight and the ratio dgo/dio of the weight distribution of the primary particles is at least 2.8. Use as constituent of fluorescent tubes.