Abstract: This paper is a study of light stabilizer which tums yellowing in the thermal process. Chemical kinetics and Arrhenius equation were used in this study. Our data showed that the yellowing rate of liquid benzotriazole type UV absorber was influence in different temperature. The kinetics model of light stabilizer which tums yellowing was first-order reaction and activation energy was calculated by the Arrhenius equation in this demonstration.The Beer's law is to test the absorption of visible at 460 nm. Data also show its high correlation with the APhA color of light stabilizer. The results confirmed that the factor of thermal yellowing is not light stabilizer. The main factors are impurities. Therefore, it was important to choose a thermal stable light stabilizers to reduce the color change of refinish coatings in the thermal aging.

Key words: refinish coatings, light stabilizer, durability, thermal stability

摘要： 应用化学动力学和阿伦尼乌斯方程式研究了修补涂料中光稳定剂对涂膜耐热老化黄变性能的影响。实验结果显示:在不同温度下,液态型苯并三唑类光稳定剂的外观会随时间变化越来越黄,且反应级数为1级;另外根据阿伦尼乌斯方程式计算热老化黄变活化能,以及利用比尔定律观察可见光在460 nm的吸收,发现其与涂膜外观颜色(APHA)有高度正相关,说明造成涂膜热老化黄变的因子不是光稳定剂分子本身,而是其中的不纯物。因此为了减缓修补涂料涂膜热老化黄变,应选择热稳定性能较好的紫外光吸收剂。

关键词: 修补涂料, 光稳定剂, 耐候性, 热稳定性