Chemical name: Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide CAS No.:162881-26-7 Molecular formula:C26H27O3P Molecular weight: 418.46 Appearance: Yellow crystal powder Purity (HPLC), %: ≥99 Melting point, ℃: 130 - 133 Volatility, %: ≤ 0.2 Acidity, mgKOH/g: ≤ 0.3 Clarity: Clear Photoinitiator 819 is a high effective UV photoinitiator, which is used to initiate the UV polymerization of unsaturated prepolymer system. It has been widely used in coatings, inks, adhesives and other industries for their excellent properties. It has great absorption in the ultraviolet and visible regions, and can initiate curing more effectively than other photoinitiators for coatings containing pigments. It hardly yellows after curing and long-term light radiation, so it can be used in occasions where yellowing requirements are stricter, such as white, light ink and paint. In addition, it has bleaching effect on light, which can penetrate the coating and help the thick film to be cured thoroughly.