819 is a high efficient universal UV initiator used to initiate UV polymerization of unsaturated prepolymerization system. It can be used for curing thick film system, especially for white system and glass fiber reinforced polyester、styrene system. Can be used for wood, metal, plastic, paper and fiber surface printing ink and prepreg system. Can make the coating has excellent curing effect and anti-UV yellowing performance. 819 has excellent absorption performance, so it can be used in thick film system.