Sumitomo Chemical Company, Limited

Toshiaki Kishimoto

Yoshiaki Hayashi

Hiroki Inoue

Keisuke Ito

Iwao Sakaguchi

Katsutoshi Numano

Taira Fujita

Hiroshi Okayasu

Kunitoshi Takahashi

4,4'-Diamino-1,1'-dianthraquinonyl compounds which are obtained in a known manner and which are easy to agglomerate or aggregate owing mainly to their too fine particle size are conditioned by heating an aqueous suspension consisting essentially of the 4,4'-diamino-1,1'-dianthraquinonyl compound and water in the presence or absence of a mineral acid or an alkali. The thus obtained 4,4'-diamino-1,1'-dianthraquinonyl pigments are used in paints, printing inks, coloring of plastics and the like. The aqueous suspension is preferably prepared by desulfonating a 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid compound in a mineral acid such as sulfuric acid and then mixing the desulfonation reaction mixture with water or by once isolating the resulting 4,4'-diamino-1,1'-dianthraquinonyl compound and mixing the isolated compound with water.

Process for producing 4,4'-Diamino-1,1'-dianthraquinonyl pigments

Crude 4,4'-diamino-l,l'-dianthraquinonyl-3,3'-disulfonic acids or salts thereof are purified by subjecting an aqueous solution containing the crude products to salting-out using inorganic salts, the aqueous solution being adjusted within a range of from acid to neutral region, whereby a product usable as such for the production of 4,4'-diamino-1,1'-dianthraquinonyl red pigments having excellent pigmentary properties is obtained in high yields with industrial advantages.

Process for purification of crude

A desulfonation reaction mixture of 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid obtainable in a conventional manner is mixed in the form of an aqueous acid suspension with a surface active agent, followed by filtration, whereby filterability and flowability of the produced 4,4'-diamino-1,1'-dianthraquinonyl pigment are efficiently improved.

Process for producing 4,4'-diamino-1,1,'-dianthraquinonyl pigments

Copper phthalocyanine pigment which is a coloring material for ink or paint is prepared by allowing, for example, phthalate, urea, and cuprous chloride to react in a hydrophilic solvent in the presence of a catalyst and at least one element selected from the group consisting of aliphatic tetracarboxylic acids, benzophenone 3,3',4,4'-tetracarboxylic acid or anhydride thereof, pyromellitic acid or anhydride thereof, copper phthalocyanine sulfonic acids, copper phthalocyanine carbonyl imide, tetrahydrophthalic acid or derivative thereof, pyromellitic imide or derivative thereof, sulfophthalic acid, derivative thereof or the salt thereof and benzene carboxylic acid.

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Osaka, Japan

Toshiaki Kishimoto