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:
Mar. 23, 2004
Filed:
Aug. 21, 2001
Hermann-Jens Womelsdorf, Leverkusen, DE;
Werner Hoheisel, Köln, DE;
Gerd Passing, Köln, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A method for the preparation of nano size zinc oxide particles having an average primary particle diameter of less than or equal to 15 nm, which are redispersible in organic solvents and/or water, by basic hydrolysis of at least one zinc compound in alcohol or an alcohol/water mixture. The hydrolysis is carried out with substoichiometric amounts of base, based on the zinc compound. The precipitate which originally forms during hydrolysis is left to mature until the zinc oxide has completely flocculated. This precipitate is then thickened to give a gel and separated off from the supernatant phase.