水杨酸酯类紫外线吸收剂
水杨酸酯类紫外线吸收剂是应用最早的一类,水杨酸酯在分子中也有内在氢键。这类紫外线吸收剂对紫外线吸收的能力在开始时很低,而且吸收的范围极窄(小于340vm),但经紫外线照射一定时间后,对其吸收逐渐 增大,直到最大吸收,这是由于其在紫外线照射下发生分子重排,形成了紫外线吸收能力强的二苯甲酮结构,从而强化其紫外线吸收作用。
Salicylates are the first UV absorbers, and they also have intrinsic hydrogen bond in the molecule. This kind of UV absorbers have very low UV absorption ability at the beginning, and the absorption range is very narrow (less than 340vm), but after UV irradiation for a certain period of time, their absorption gradually increases until the maximum absorption, which is due to the molecular rearrangement under UV irradiation, forming a benzophenone structure with strong UV absorption ability, so as to strengthen their UV absorption Effect.