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:
Dec. 09, 1997
Filed:
Oct. 07, 1996
Klaus-Dieter Thiel, Karlsruhe, DE;
Herbert Heinisch, Ettlingen, DE;
Abstract
In the production of spherulitic nitroguanidine having a high bulk and tap ensity nitroguanidine is dissolved in dipolar, aprotic solvents, e.g. DMF, DMSO, NMP, etc., by heating to above the saturation temperature t.sub.s and the supersaturated solution is cooled with a controlled temperature gradient (.degree.C./min), crystallization being assisted by the addition of particulate, spherulitic material. In order to obtain spherical nitroguanidine with high yield in a continuous process and with mother liquor reuse, during the heating to above the saturation temperature t.sub.s, spherical control particles with a diameter of 5 to 500 .mu.m are regularly added to the solution in a quantity of 0.05 to 5.00 mass %. The particle size is chosen in such a way that, as a function of the solution behaviour of the nitroguanidine used and its concentration, on dropping below the saturation temperature spherical control particles are still present in the indicated quantity in the supersaturated solution.