Sub-product Red New Process And Downstream Product Development

By-product magenta is an important chemical intermediate used primarily as a raw material for the manufacture of rubber and metal adhesives,polyisocyanate adhesives,Lekner adhesives.The traditional process uses sodium polysulfide as a reducing agent,redoxes p-nitrotoluene in an ethanol medium,and then condenses with aniline in the presence of hydrochloric acid,and is refined to obtain a finished product.Due to the complicated production process and long production cycle,the intermediate products such as sodium polysulfide and p-aminobenzaldehyde have low purity,resulting in low yield of the final product.The cavitation of ultrasonic waves,as well as the accompanying chemical and mechanical effects,can promote heterogeneous chemical reactions,chemical reactions between macromolecular species,and reactions between other free radicals.On the basis of the traditional process,ultrasonic waves are introduced,and the sound wave direction is good,the penetrating ability is strong,the reactants are fully contacted,the reaction is rapid,and the desired product is high in selectivity,thereby reducing the reaction time and increasing the product concentration.Under the action of ultrasonic wave,the effects of process conditions such as reaction time,reaction temperature and reactant mass ratio on the yield of sodium polysulfide were investigated.Experiments show that when the reaction time is 50 min,the reaction temperature is 80 °C,and the reactant mass of sodium hydroxide and sulfur are 30:32,the obtained sodium polysulfide content and polysulfide index meet the requirements.Compared with the traditional method,the reaction time is shortened from 3.5 h to 50 min,the efficiency is greatly improved,the energy consumption is reduced,and the quality of sodium polysulfide reaches the required standard.Under the action of ultrasonic wave,the effects of process conditions such as reaction time,reaction temperature and reactant mass ratio on the yield of p-aminobenzaldehyde were investigated.The product was determined by gas chromatography to determine the reaction time was 1.5 h,the reaction temperature was 80 ° C,and the optimum reaction conditions were obtained when the ratio of p-nitrotoluene mass(g)to sodium sulfide(0.5 mL)was 0.58;The process conditions for the synthesis of p-aminobenzaldehyde showed that the catalytic effect was best when N,N-dimethylformamide(DMF)was used as the catalyst and the amount of p-nitrotoluene was 1/20.The yield of formaldehyde reached 69.95%.The experiment was repeated under the above optimal conditions.The product was characterized by infrared absorption spectroscopy.The reaction kinetics of p-aminobenzaldehyde was synthesized by ultrasonic wave.The activation energy of ultrasonic synthesis of p-aminobenzaldehyde was obtained.The emission energy is 14.205 kJ/mol,which is lower than that of the traditional process.Under the action of ultrasonic wave,the effects of process conditions such as reaction time,reaction temperature and reactant mass ratio on the yield of by-product magenta were investigated.The results showed that the reaction time was 1.5 h and the reaction temperature was 80 °C.When the mass ratio of aniline to p-aminobenzaldehyde was 1.7:1,the yield of by-product magenta reached the highest,72.55%.The product was subjected to infrared microscopy and Characterization by liquid chromatography-mass spectrometry.In order to further study the application of the downstream products of the sub-magenta,the process conditions for the synthesis of tris(4-acetamidophenyl)methane were investigated under the aid of ultrasound.The results showed that the reaction temperature was 30 ° C,the reaction time was 20 min,and the mass ratio of the by-product fuchsin to chloroacetyl group was 1:26.The yield of tris(4-acetamidophenyl)methane was the highest,86.7%.Characterized by liquid chromatography-mass spectrometry.The use of ultrasonic cavitation and other accompanying effects not only accelerates the reaction rate,saves energy,but also increases product yield,reduces by-product formation,and avoids environmental pollution.