Ultraviolet absorber is a kind of light stabilizer, which can absorb the ultraviolet part of sunlight and fluorescent light source without changing itself.
Since the sun's rays contain a large amount of ultraviolet light that is harmful to colored objects, the wavelength is about 290-460 nanometers. These harmful ultraviolet light through chemical redox reaction (Redox reaction), make the color molecules finally decompose and fade.
There are both physical and chemical methods to prevent harmful ultraviolet light from damaging colors.
Here is only a brief introduction to chemical methods, that is, the use of ultraviolet absorbers to effectively prevent or weaken the damage to the color of the protected object.
UV absorbers should have the following conditions
①It can absorb ultraviolet rays strongly (especially the wavelength is 290-400nm); ②Good thermal stability, it will not change due to heat even during processing, and the thermal volatility is small; ③Good chemical stability, not compatible with the materials in the product Adverse reactions occur to the components; ④Good miscibility, can be evenly dispersed in the material, without blooming or exudation; ⑤The absorber itself has good photochemical stability, does not decompose, and does not change color; ⑥Colorless, non-toxic, Odorless; ⑦ resistant to immersion washing; ⑧ cheap and easy to obtain; 9. insoluble or hardly soluble in water.
UV absorbers can be divided into the following categories according to their chemical structure: salicylate, benzophenone, benzotriazole, substituted acrylonitrile, triazine and hindered amine.
