Stydy On The Process For Synthesis Of Dye C.I. Solvent Yellow 44

The characteristic of solvent dyes is that can dissolve in the organic solvent. C.I. Solvent Yellow 44 has the nature that it can launch the fluorescence after absorbing the sunlight or the ultraviolet ray. The product can be used as many kinds of fluorescence pigments in the the coloration of plastic and the production of colored fluorescence paint. The artificial azo dyes that is suitable for dying of polyester, polyamide, acetate fiber can be prepared starting from the product by diazotation of the amino.Based on reviewing the bibiographer and analyzing principles of processes the process for preparation of C.I. Solvent Yellow 44 was studied in the dissertation. It was prepared sarting from 1.8-naphthalic anhydride by Chlorination in water, condensation with 4-dimethylaniline in acetic acide and ammonolysis with ammonia in isopropyl alcohol.The difference of the halogenating agent to use the chlorine and the bromine was investigated in experiments. The optimum halogenating reaction conditions were evaluated and the results showed that water was the proper solvent and the appropriate temperature was 0～5℃, the Ph value was 5～6, reaction time 12 hours.the yield reached 90%.In the condensation reaction, the factors of temperature, the mole ration was studied. The proper conditions of condensation were obtained as following: the glacial acetic acid as the resolver, the reaction temperature 118～120℃, the mole ration of 2,4- xylidine and halogenide 1.05: 1, reaction time 12 hours. the yield reached 95%. The key point in the experiment was the condition of ammonolysis reaction. The influence of catalyst, temperature, reaction time was discussed. The optimum conditions were selected as following : the isopropyl alcohol as the resolver, the ammonia as the ammonolysis reactant, the reaction temperature 240～250℃, reaction time 12 hours. The yield reached 90%.Based on the results of the experiments the optimum process parameters and the rational industrial scheme were selected and designed. The results of the process data in test of industrial set were accorded with those of the experiments. There were several typical advantages of the process such as stability of the process and low-cost of the product.It provided the theoretical basis for the optimum of the industrial set of the produt.