2021

What is UV Absorber?

UV absorber is a kind of light stabilizer, can absorb the ultraviolet part of sunlight and fluorescent light source, and itself does not change. Plastics and other polymer materials in sunlight and fluorescence, due to the role of ultraviolet light, produce automatic oxidation reaction, resulting in the degradation of polymers and deterioration, so that the appearance and mechanical properties of bad. After the addition of the ultraviolet absorber, such high-energy ultraviolet rays can be selectively absorbed to be released or consumed as harmless energy.

Different types of polymers have different ultraviolet wavelengths that degrade them. Different ultraviolet absorbers can absorb ultraviolet rays of different wavelengths. When used, ultraviolet absorbers should be selected according to the type of polymer.

The ultraviolet absorber should have the following conditions: ① it can strongly absorb ultraviolet rays (especially the wavelength is 290-400nm);② good thermal stability, even in processing, it will not change due to heat, and the thermal volatility is small; ③ good chemical stability, no adverse reaction with the material components in the product; ④ good miscibility, can be evenly dispersed in the material, no frost spray, no exudation; ⑤ The photochemical stability of the absorbent itself is good, does not decompose, does not change color; ⑥ colorless, non-toxic, odorless; ⑦ resistance to immersion; ⑧ cheap, easy to get. Ultraviolet absorbers can be divided into the following categories according to their chemical structures: salicylates, phenones, benzotriazoles, substituted acrylonitriles, triazines and others.

UV absorbers are used in plastics, coatings, dyes, car windshields, cosmetics, drugs, sunscreens, etc.