Reacción #514371

Ecuación de reacción

2,5-dianilinoterephthalic acid

2,5di(3-chloroanilino) terephthalic acid

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quinacridone

Condiciones de reacción

Procedimiento

450 parts of polyphosphoric acid containing 85.0% P2O5 are metered into a stirred vessel. Then 142.5 parts of 2,5-dianilinoterephthalic acid and 7.5 parts of 2,5di(3-chloroanilino) terephthalic acid are introduced at 125° C. with stirring and the mixture is heated at 125° C. for 1 hour during which ring closure takes place to form the quinacridone. The reaction mixture is subsequently metered with stirring over 2 minutes (CG: 50%/min) into 860.8 parts of 85% strength phosphoric acid at 140° C., during which it is hydrolyzed. During this hydrolysis the temperature rises to 160° C. The phosphoric acid concentration after the hydrolysis is 95%. Then 1105 parts of 40% strength phosphoric acid are added dropwise and the suspension is cooled to 120° C. The phosphoric acid concentration thereafter is 70%. The mixture is stirred at 120° C. for 4 hours. The mixture is then cooled to 110° C. and the mixed crystal pigment is filtered off with suction, washed with 70% strength phosphoric acid until the runoff is colorless, washed to neutrality with water, and dried at 80° C. This gives 127.1 parts of mixed crystal pigment (Pigment Violet 19, γIV phase). At twice the Bragg angle, 2θ, X-ray spectrum shows four strong lines at 6.5°, 13.5°, 13.7° and 26.4°, five moderate lines at 13.0°, 16.9°, 23.8°, 25.2° and 28.2°, and four weak lines at 20.5°, 21.4°, 30.4° and 31.7°.

Fuente