BDK/651 (Benzil Dimethyl Ketal) is a new type of ultraviolet photosensitizer with excellent performance. It can produce highly active methyl radicals under ultraviolet light at a usage amount of 0.5% to 5%. It is compatible with other benzoin. Compared with ether-based photosensitizers, it has the advantages of high photoinitiation efficiency and dark storage stability. It is widely used in the polymerization of acrylate, methacrylate, acrylonitrile, acrylamide, styrene, maleic acid, fumaric acid and other unsaturated monomers and their mixtures, as well as the polymerization of unsaturated monomers and polyvinyl alcohol, polyvinyl alcohol and polyvinyl alcohol. Polymerization and cross-linking of oligomers such as phenol.it is widely used as an initiator in the manufacture of paints, coatings, inks, adhesives and resins.