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. 26, 1985
Filed:
Feb. 10, 1983
Applicant:
Inventors:
Ernst Spietschka, Idstein, DE;
Helmut Troster, Konigstein, DE;
Assignee:
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549232 ; 546 37 ;
Abstract
Perylene-3,4,9,10-tetracarboxylic acid monoanhydride mono-sodium or mono-potassium salts are obtained from neutral salts of perylene-3,4,9,10-tetracarboxylic acid, if necessary in the presence of at least one molar equivalent of sodium or potassium ions, at 20.degree. to 100.degree. C. by adding three molar equivalents of a sufficiently strong acid. The products are dye precursors, especially for asymmetric N-substituted perylenetetracarboxylic acid diimide pigments.