甲醛法合成受阻胺光稳定剂625

Synthesis of HALS 625 from Formaldehyde

摘要:

本文以受阻胺光稳定剂360为主要原料，以甲醛为甲基化剂，以甲苯为溶剂，通过甲基化反应合成受阻胺光稳定剂625，产物结构经1HNMR进行了确证。通过单因素实验以及正交实验，确定了适宜的甲基化反应条件为n(360):n(甲醛)=1:4.6，反应温度为85℃，反应时间为6h。在此条件下，甲基化率为97.4%。与甲醛/甲酸法相比，该反应过程无需加入甲酸，避免了光稳定剂360与甲酸成盐结块的问题，同时避免了繁琐的后处理过程，简化了操作，降低了成本，具有甲基化率较高和产物颜色较浅等优点。

Abstract:

The hindered amine light stabilizer 625 was synthesized by methylation reaction from hindered amine light stabilizer 360 and paraformaldehyde in toluene, and the structure was elucidated by 1HNMR. Via the single factor experiments and the orthogonal experiments,the suitable methylation conditions were obtained as follows, n(360):n(formaldehyde)=1:4.6, the reaction temperature was 85℃, and the reaction time was 6h. Under these conditions, the methylation rate was 97.4%. Compared with the formalde-hyde/formic acid method, formic acid wasn’t required inthe reaction. The method avoided the problem of salt-forming agglomeration of the light stabilizer 360 with formic acid and of the cumbersome workup, simplified the operation, reduced the cost. It has the advantages of higher methylation rate and lighter product color.