Research Of The Synthesis And Pigmentation Of DPP Organic Pigments

The present paper relates to the preparation of l,4-diketopyrrolo-[3,4-C]-pyrroles pigments, the influence of the reaction factors, such as catalyst, succinate etc. The paper researched the preparing of C.I. Pigment Red 254 (DPP 254) and C.I. Pigment Red 255 (DPP 255). Moreover, the influence of the reacting factors, such as catalyst, materials ratio, time, temperature etc on the yield, color, shade and other important properties of DPP pigments were studied. Then the factors were finally defined. DPP 254 was synthesized from 4-Chlorobenzonitrile and di-isopropyl succinate with high yield of 85.3%. The conclusions were drawn as follows: n(sodium tert-butylate):n(di-isopropyl succinate) was 5.5, n(4-chlorobenzonitrile):n(di-isopropyl succinate) was 1.95, the temperature was 110℃, the time was 4h. And DPP 255 was synthesized from benzonitrile and di-isopropyl succinate with high yield of 62.5%. The conclusions were drawn as follows: n(sodium tert-butylate) : n(di-isopropyl succinate) was 3, n(benzonitrile):n(di-isopropyl succinate) was 2.4, the temperature was 105℃, the time was 3.5h.The paper adopted different conditioning methods, the solvent treatment and using different surface processors, to get the pigmentation of DPP 254 during the synthesis process of pigment (1 step pigmentation) or after it (2 steps pigmentation). The influence of the pigmentation factors, such as surface processor, solvent, time, temperature etc on the color, shade and other important properties of DPP 254 were studied. Then a kind of conditioning method was found and the factors were finally defined. The pigment was tested by color, shade, transparence, crystal shape, fluidity etc. According to the test, the pigment has fresh color, good hiding capability, high fluidity and other excellent capabilities. The pigment can compare beauty with Ciba standard sample.The paper combined with acquired patent to create a new way of synthesis for preparing N-substituted DPP. Then a part of the synthesis method was attested that it's feasible.