The Synthesis Of Azo Dyestuff Reactive Black 5

From 2000 to 2005, the production of China's dyestuff increased from 300, 000 tons to 640,000 tons (containing organic pigments), accounting for more than 60% of the global dyestuff production. However, dyes were produced by batch production, printing and dyeing industry, a reflection of the quality of domestic products dyes, in addition to application performance is not satisfactory, the most important is the stability of product quality, that the differences between different batches.Reactive Black KN-B, also called C.I. Reactive Black 5 (C.I.20505, number of International Colour Index), is a large amount of dual-reactive group dye, this dye has the advantage of cheap, less direct and better leveling nature of good wet fastness, meet environmental requirements, is still a deep dark blue black reactive dye composition in the preferred varieties. Almost all goods are active components of black to dark blue C.I. Reactive Black 5, the main component, accounting for three primary colors of their content, more than 70%.The synthesis process of C.I. Reactive Black 5 was studied in this paper. and searched the optimal craft parameters of C.I. Reactive Black 5, and studied the speed of rotating packed bed and stay time on the diazotization and coupling reaction, has done a super Synthesis of azo dyes gravity machine attempts. The yield of rotating packed bed was more than the yield of batch stirred tank by about 10%.The optimal conditions of synthesis of Reactive Black 5 in batch agitator is as this:1. Optimum conditions of para-ester diazotization reactionreaction time:30min; the molar ratio of hydrochloric acid and para-ester:3.0; the molar ratio of sodium nitrite and para-ester:1.05; reaction temperature:10℃; rotating speed:600rpm.2. Optimum conditions of coupled reaction in acid medium reaction time:15min; H acid and the molar ratio of the bit ester:1.0; reaction temperature:15℃; stirring speed:900rpm, pH=3-4.3. Optimum conditions of coupled reaction in base medium reaction time:15min; reaction temperature:15℃; rotating speed: 900rpm, pH=8-9.The optimal conditions of synthesis of Reactive Black 5 in rotating packed bed is as this:para-ester diazotization reaction:rotating speed,1120 rpm, feeding flow 320ml/sec; coupled reaction in acid medium:rotating speed,1680rpm, feeding flow rate of 120ml/sec, coupled reaction in base medium:rotating speed,1120rpm, feeding flow:120ml/sec.