At present, the ideal UV absorbers/light stabilizers are mostly compound types, especially compounded with salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, triazines and hindered amines. It can achieve a more rational effect than any single UV absorber. Application fields of UV absorbers: polymers (plastics, etc.), coatings (automotive spray paint, building finishing), printing inks, post-treatment of dyed/printed textiles, sunscreen cosmetics.
Since the sun's rays contain a large amount of ultraviolet light harmful to colored objects, its wavelength is about 290-460 nanometers, these harmful ultraviolet light through chemical redox reaction (Redox reaction), so that the color molecules finally decompose and fade. Ultraviolet absorbers prevent There are both physical and chemical methods by which harmful ultraviolet light can destroy colors.
Here we only briefly introduce the chemical method, that is, the use of ultraviolet absorbers to effectively prevent the protected objects, or weaken their damage to the color.
① can strongly absorb ultraviolet light (especially the wavelength of 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 material components in the product;
④ Good miscibility, can be evenly dispersed in the material, no frost, no seepage;
⑤ The photochemical stability of the absorber itself is good, no decomposition, no discoloration;
⑥Colorless, non-toxic, odorless;
⑦ soaking resistance;
⑧ cheap and easy to get;
⑨. Insoluble, or hardly soluble in water.
UV absorbers can be divided into the following categories according to their chemical structures: salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, triazines, and hindered amines.
