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:
Feb. 13, 1990
Filed:
Feb. 04, 1988
Wilhelm Holtmann, Munster, DE;
Robert Zellerhoff, Hamminkeln, DE;
Rudolf Oberkobusch, Duisburg, DE;
Peter Staglich, Kempen, DE;
Bernhard Charpey, Mulheim an der Ruhr, DE;
Rutgerswerke AG, , DE;
Abstract
In a process for selective crystallization of 2,6-dialkyl-naphthalene selected from the group consisting of methyl-n-propyl-naphthalene, methyl isopropyl-naphthalene, ethyl-isopropyl-napthalene, ethyl-n-butyl-naphthalene, di-n-propyl-naphthalene, diisopropyl-naphthalene, methyl-amyl-naphthalene, ethyl-amyl-naphthalene, propyl-amyl-naphthalene, di-n-butyl-naphthalene and diisobutyl-naphthalene from their isomer mixtures from a polar solvent solution, the improvement comprising effecting the crystallization with constant stirring at a temperature from 25.degree. to -30.degree. C. to obtain the 2,6-dialkyl-naphthalene at least 95% pure.