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:
Jul. 13, 2010
Filed:
Jun. 06, 2003
Peter Erk, Frankenthal, DE;
Simone Schaefer, Kleinfischlingen, DE;
Arno Boehm, Mannheim, DE;
Peter Blaschka, Ludwigshafen, DE;
Harald Arms, Hohen-Suelzen, DE;
Willi Helfer, Friedelsheim, DE;
Peter Erk, Frankenthal, DE;
Simone Schaefer, Kleinfischlingen, DE;
Arno Boehm, Mannheim, DE;
Peter Blaschka, Ludwigshafen, DE;
Harald Arms, Hohen-Suelzen, DE;
Willi Helfer, Friedelsheim, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
Novel crystalline forms of and a process for converting perylene-3,4:9,10-tetracarboximide of the general formula I to a form used as a fluorescent dye. The process including: a) dissolving or suspending the perylene-3,4:9,10-tetracarboximide in a solvent to obtain a solution or suspension; and b1) cooling the solution obtained in step a) to a temperature at or below the crystallization temperature of the perylene-3,4:9,10-tetracarboximide and, if the solvent is organic, removing excess solvent until the first crystals form, otherwise, adding water or dilute aqueous solutions of the solvent until the first crystals form, and maintaining the solution at that temperature for further crystallization; or b2) cooling the suspension obtained in step a) to or below the crystallization temperature when the temperature in step a) was above the crystallization temperature, and maintaining the suspension at the temperature for further crystallization to form one or more solvate crystals.