Document Type and Number:
Japanese Patent JPS6315308
Kind Code:
B2
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.
Inventors:
FURIDORIN BEEBURERU
Application Number:
JP6137879A
Publication Date:
April 04, 1988
Filing Date:
May 18, 1979
Export Citation:
Assignee:
CIBA GEIGY
International Classes:
C09B3/18; C08K5/09; C09B3/14; C09B5/00; C09B67/18