Used as a UV absorber, 2- hydroxy -4- methoxy two benzophenone derivative by the product (UV-9), 2- hydroxy -4- octyloxy two benzophenone (UV-531) two benzophenone compounds, and other single hydroxyl, hydroxyl, hydroxyl, three dual four hydroxyl groups is the most widely used absorption light stabilizer. Can absorb ultraviolet 290-400 nm, and the majority of synthetic resin has good compatibility, is widely used in polymer materials. 2, 4- two hydroxy two benzophenone for polyvinyl chloride, polystyrene, epoxy resin, unsaturated polyester resin, fiber, coatings and synthetic rubber. The maximum absorption wavelength range of 280-340 nm, the general amount of 0.1-1%. But the light effect on the stability of the product is not obvious. The product of the rat oral LD50 8600 mg / kg, 2336 mg / kg in mice.