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:
Oct. 21, 1997
Filed:
Aug. 03, 1995
Uwe Klingler, Dormagen, DE;
Thomas Schieb, Rosrath, DE;
Gerhard Wiechers, Leverkusen, DE;
Jurgen Zimmermann, Walnut Creek, CA (US);
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
Dinitrotoluene is produced in a two-stage process from toluene and nitric acid in the presence of sulfuric acid under adiabatic conditions in the presence of nitrating acids made up of specified components. The reaction product of the first phase is separated into an acid phase and an organic phase containing the mononitrotoluene. Some water is removed from the acid phase, nitric acid is added and the resultant mixture is recycled. The organic phase containing mononitrotoluene is further nitrated to produce the dinitrotoluene. This nitration mixture is also separated into an acid phase and an organic phase. The acid phase is treated to remove some water, nitric acid is added and the resultant acid mixture is recycled. Dinitrotoluene is recovered from the organic phase. This process is advantageous in that dilute nitric acid may be used and the heat of the nitration reaction is utilized.