The chemical name of 1173 (1103) photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-acetone, abbreviated as HMPP. The structural formula is c6h5coc (CH3) 2OH, with a molecular weight of 164.20. Colorless or yellowish transparent liquid. Boiling point 102 ~ 103 ℃ (0.53kpa). Soluble in toluene, acrylate, methacrylate, etc. It is easily miscible with resin, with high initiation efficiency, good thermal stability, no yellowing, and stable storage. UV absorption wavelength is 260 ~ 360nm.

1173 is the most successful photoinitiator and one of the most widely used yellowing free photoinitiators in China, with a maximum absorption wavelength of 331nm. The light curing adhesive was prepared by mixing with polyester, acrylate, active diluent, etc., but in the unsaturated polyester / styrene system, the photoinitiation efficiency of HMPP was inferior to that of benzoin ether photoinitiator. It can also be used in aqueous UV curing system. The reference dosage is 1.0% - 5.0%. The photoinitiator is not suitable for occasions with strict odor requirements. The reason is that the residual initiator is volatile, and the photolysis of the initiator produces trace benzaldehyde and acetone, which will lead to excessive odor.