Sulfuric Acid → Diketopyrrolopyrrole

Participants

Reaction Steps

The pigment dispersant A1 of Synthesis Example A1 (3.75 parts) and C.I. Pigment Red 254 (6.25 parts) were added to 95% sulfuric acid (100 parts), followed by stirring at room temperature for 1 hour. Subsequent to cooling, the resulting concentrated sulfuric acid solution was poured into iced water (1,000 parts); its pouring led the precipitation of a composite according to the present invention. The formed precipitate was collected by filtration and then washed with water to obtain a water-based paste (39 parts, true amount: 10 parts). The water-based paste was dried to obtain a diketopyrrolopyrrole (a pigment dispersant A3, 10 parts), which was determined to contain on average 0.3 sulfonic group introduced per molecule from the results of an elemental analysis for sulfur.

Provenance & Evidence