【摘要】 概述了荧光增白剂DT的用途及其合成工艺.对利用苹果酸进行Ladenburg反应合成DT的反应机理进行了全新的理论探讨.在此基础上,对8个反应条件的选择进行了讨论,提出了控制要点和主要问题的解决方法.认为由邻氨基对甲苯酚与苹果酸反应,二甲苯作溶剂,硼酸作催化剂,经脱水、蒸馏、净化等工序的合成工艺具有诸多优点,按优化反应条件:邻氨基对甲苯酚与苹果酸物质的量比为2∶1￣2∶1.05;除初始升温阶段外,反应温度分三段控制:第一阶段140℃左右,第二阶段170℃以下,第三阶段190℃以上,所合成的产品白度高而收率达85%以上.并对今后的研究方向和方法提出了建议.更多还原

【Abstract】 The uses and synthetic processes were summarized. The new theory for the reaction mechanism of DT synthesis by Ladenburg reaction of malic acid was investigated. The selection of the 8 reaction conditions was discussed on this basis, and the essential controls and the resolution of the principal problems were proposed. The following process was believed to have many advantages: reaction of o-amino-p-cresol with malic acid in xylene solvent with boric acid as the catalyst, followed by dewatering, distn., purifn. etc. The optimal mol. ratio of o-amino-p-cresol and malic acid was 2∶1 ~ 2∶1.05. The reaction temps. after the initial temp. rising could be divided into 3 stages: 140 ℃ for the first, 170 ℃ for the second and above 190 ℃ for the third stage. The product was of high whiteness and the yield surpassed 85%. The future research directions and methods were also proposed.更多还原