UV absorber is a kind of light stabilizer, which can absorb the ultraviolet part of sunlight and fluorescent light source without changing itself.

UV absorbers are currently the most widely used light stabilizers. According to their structure, UV absorber  can be divided into salicylic acid esters, benzophenones, benzotriazoles, substituted acrylonitriles, triazines, etc. The most widely used are benzophenones and benzotriazoles. 

UV absorbers should have the following conditions:
1. It can strongly absorb ultraviolet light (especially the wavelength is 290-400nm);
2. Good thermal stability, it will not change due to heat even during processing, and the thermal volatility is small;
3. Good chemical stability, no adverse reaction with material components in the product;
4. Good miscibility, can be evenly dispersed in the material, no blooming, no exudation;
5. The absorber itself has good photochemical stability, does not decompose, and does not change color;
6. Colorless, non-toxic and odorless;
7. Resistance to soaking;
8. Cheap and easy to get;
9. Insoluble or insoluble in water.