Organic Pigment Yellow Series Synthesis And Modification

The series of organic yellow pigment are the most important kind of pigments. And yellow pigment 12, yellow pigment 13,and yellow pigment 83 are most widely used of the series of organic yellow pigment. The yellow pigment 12, 13, and 83 are synthesized by 3,3'-dichlorobenzidine through diazotization reaction, and the couple reaction. The influencing factors of the performance of pigment are studied by testing the applied performance of the pigment in printing ink. And when the diazotization reaction happens under the conditions that the agitated speed more than 300 rpm, the temperature is between 5℃ and 10℃, 3,3'-dichlorobenzidine is added in 40 minutes, the concentration proportion of nitrous sodium and 3,3'-dichlorobenzidine is 1.2: 1, and the acid concentration is 2.4mol/L, the pigment shows greater applied performance than those prepared under other conditions. And when the couple reaction happens under the condition that the agitated speed more than 600 rpm, the diazo salt is added in 50 minutes, the temperature is between 5℃ and 10℃, and pH is 5, the yellow pigment 12 and 13 show greater performance. When the yellow pigment 83 is synthesized, the agitated speed is controlled more than 600 rpm, and the diazo salt is added in 40-50 minutes during the low temperature 5~10℃, and pH is 5, when the temperature is 70℃, the diazo salt is added in 90 minutes.The impurity affects the applied performance of the pigment, the constitute of the impurity and the second reaction are concluded by analyzing the reaction mechanism.SEM and XRD are used to analyzing the relation between the applied performance of organic pigment and the crystal modality. The conclusion is that the applied performance is not only affected by the crystal modality, but also by the distribution of the particulate size.