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:
Jan. 31, 1995
Filed:
Jun. 01, 1994
Ursula Pentling, Kempen, DE;
Hans-Josef Buysch, Krefeld, DE;
Lothar Puppe, Burscheid, DE;
Kai Rohlk, Bergisch Gladbach, DE;
Rolf Grosser, Leverkusen, DE;
Hans-Ingolf Paul, Koln, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
Mixtures of m- and p-dichlorobenzene can be separated by treating such mixtures in the liquid phase with a pentasil zeolite at from 20.degree. to 250.degree. C., a filtrate enriched in m-dichlorobenzene being removed and the p-dichlorobenzene being obtained by desorption of the pentasil zeolite. The pentasil zeolites may contain, as exchangeable cations, protons, cations of the first or second main group of the Mendeleev Periodic System, cations of the rare earth metals or a mixture of a plurality thereof. In order to prepare the liquid phase a solvent is used that belongs to the group of cyclic saturated hydrocarbons having 5 to 15 carbon atoms, alkyl-substituted aromatic hydrocarbons having 8 to 12 carbon atoms, and halogen-substituted aromatic hydrocarbons having 6 to 10 carbon atoms and 1 to 3 halogen atoms. The solvents ethylbenzene, chlorobenzene, p-xylene, p-chlorotoluene and dichlorobenzene are excepted. A mixture of a plurality of these solvents may also be used.