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:
Nov. 06, 2001
Filed:
May. 04, 2000
Harald Werner, Bad Homburg, DE;
Elke Schweers, Bad Soden, DE;
Frank Olschewski, Unterliederbach, DE;
Gerhard Geiss, Liederbach, DE;
Elfriede Hufsky, Rodheim, DE;
Helmut Tränkler, Frankfurt, DE;
Heinz Alexander, Frankfurt, DE;
Ticona GmbH, , DE;
Abstract
A process for the gas-phase trimerization of formaldehyde to give trioxane using solid phosphoric acid catalysts. Particularly suitable catalysts for this process are SPA catalysts (solid phosphorous acid), for example “silicon phosphates”. The main advantage of this catalyst system is its simple and inexpensive production and ready availability and also, in particular, its improved long-term stability compared to the few previously described catalysts which are mostly based on supported heteropolyacids.