Plastics and other polymer materials, exposed to sunlight or high-energy rays, will undergo photo-oxidative degradation due to the absorption of ultraviolet light energy, resulting in discoloration and performance degradation of the products. Any substance that can inhibit or slow down photooxidation is called light stabilizer or anti-ultraviolet agent.
The main functions of light stabilizers are: shielding light, absorbing and transferring light energy, quenching or capturing free radicals. Light stabilizers are generally divided into four categories: light shielding agents, ultraviolet absorbers, quenchers and hindered amine light stabilizers according to their mechanism of action.
Hindered amine light stabilizer is a type of light stabilizer that is used in large quantities at home and abroad. It can decompose hydroperoxides, quench radical oxygen, trap free radicals, and its effective groups have recyclable regeneration functions.
The amount of light stabilizer in the product is generally 0.01%~0.5%, and the effect is good. The light stabilizer generally has the following conditions:
1. It can absorb ultraviolet light in the wavelength range of 290~410 nanometers, or can effectively quench the energy of excited molecules, or have sufficient ability to trap free radicals. Its light stabilization effect is long-term.
2. Good compatibility with resin, good thermal stability, no reaction with other additives, good extraction resistance.
3. Non-toxic or low-toxic, non-polluting products, low price.
