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. 28, 2014
Filed:
Nov. 30, 2010
Johann Kecht, Munich, DE;
Stephan Steinlein, Munich, DE;
Johann Kecht, Munich, DE;
Stephan Steinlein, Munich, DE;
Giesecke & Devrient GmbH, Munich, DE;
Abstract
A method for producing solid particles having a silica coating, by: dispersing the solid particles to be coated in an aqueous medium to produce a solid particle dispersion, adjusting the pH of the solid particle dispersion by a buffer system to produce a buffered solid particle dispersion, and adding an alkaline silicate solution to the buffered solid particle dispersion to form the silica coating on the solid particles during a coating period. The amounts of buffer system and alkaline silicate solution are selected such that the pH of the buffered solid particle dispersion before the addition of the alkaline silicate solution is at least 7.0 and after completion of the addition of the alkaline silicate solution is at most 11.0.