高纯度2，5-二氨基甲苯硫酸盐的清洁合成新工艺

Study on Non-pollutant and Clean Synthesis High-purity 2,5-Diaminotoluene Sulfate

2，5-二氨基甲苯硫酸盐（2，5-TDAS）是现今取代对苯二胺用于高档毛发化妆品中流行染色的主要产品．其中世界著名化妆品公司德国Welldu、P＆G、Henkel、Goldwell，法国Chimex以及日本花王（Kao）四等生产的各类染发剂品牌对2，5-TDAS质量要求甚高、有毒有害杂质控制极严（一般〈20mg／kg）。而目前市场对这种高品质2，5-TDAS产品的需求迫切，仅欧、美、日的需求量就超过600妇，但现行2，5-TDAS的工业化生产均是采用对4-硝基邻甲苯胺，即红色基RL（rb—RL）进行还原的技术，而rb—RL的制备又选用先将邻甲苯胺（OT）中的氨基进行保护、后硝化水解的合成工艺，见图12，5-TDAS合成新工艺中的式（1），

A new technology featuring clean production and economic synthesis is studied for manufacturing 2,5-diaminotoluene sulfate(2,5-TDAS)with high-purity,starting from o- toluidine(OT)through diazo-coupling,reductive hydrogenative cleavage and refine processes.The results show that the technology has the characteristics of less reaction procedures,lower cost and less pollutant,excellent product qualities and yield of 70%. Studied complex and decolorizing methods for waste water pretreatment are very efficient in clean synthesis,it makes obtaining decolorized,transparent waste water with COD below 2000.Developed recovery techniques for OT and 2,5-TDAS have good economical benefit. Using this technology to substitute current production route has a good prospect in developing 2,5-TDA series products exhibiting characteristics of energy economization,less emission and materials circulation economically.