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. 10, 1981
Filed:
May. 10, 1979
Applicant:
Inventor:
Fridolin Babler, Allschwil, CH;
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C08K / ;
U.S. Cl.
CPC ...
260 4221 ; 260 / ; 260 4246 ; 260 4249 ; 546 37 ;
Abstract
A process for the manufacture of perylenetetracarboxylic dianhydride pigments having improved dispersibility, which comprises adding at least one primary aliphatic or cycloaliphatic amine containing at least 12 carbon atoms to an aqueous alkaline solution of an alkali metal salt or ammonium salt of perylenetetracarboxylic acid, acidifying the reaction mixture, whereupon the free perylenetetracarboxylic acid precipitates and is then converted by heating the reaction mixture into the dianhydride, which is isolated in the conventional manner.