Sulfuric Acid → Alpha.-Copper phthalocyanine

Participants

Reaction Conditions

Reaction Steps

A conventional Baker-Perkins sigma blade mixer having a capacity of two cubic inches (32.8 cubic centimeters) is charged with 4.5 g of crude copper phthalocyanine, 1.5 of anhydrous FeCl3, 29.0 g of micropulverized sodium chloride, and 4.42 g of diethylene glycol. The charge is milled at 54 r.p.m. for three hours. The temperature during milling is maintained from 80°C. to 90°C. by passing steam through the mill jacket. The milled charge is then added to 500 cc of an acidic aqueous solution containing 5 cc of 98% sulfuric acid. The resulting slurry is heated to 95°C. and maintained at that temperature for one hour and thirty minutes. The pigment is isolated by filtering, washing with water to remove any residual sulfate and drying overnight at 180°F. (82°C.) to give a substantially quantitative yield of β-copper phthalocyanine exhibiting the bright green-shade blue color.

Provenance & Evidence