Synthesis And Evaluation Of Quinoxaline Photoinitiators

Compared with other traditional curing technologies, photo-curing has some advantages such as non-solvent, high-efficiency, and little pollution, and therefore has been widely used in the fields of photoresists, paintings, coatings, electronic packaging materials, adhesives and so on. In the industry of photoresist, 2,2'-bis(2-chlorophenyl)-4,4',5,5'- tetraphenyl-1,2'-biimidazole(BCIM) has been widely used, but its disadvantages is also obvious: low absorption wavelength and low solubility.To get highly efficientive photointiators for photoresist, we synthesized a series of quinoxaline photoinitiators. All of the six quinoxalines have maximal absorption wavelength in the range 350~410nm with high absorbance, which is in good accordance with industrial application. Quinoxaline/MBO was proved to be the best photoinitiating system, especially for D3MOP-BenQ/MBO with 100% conversion of A-BPE-10, and only the proper amount and proportion lead to the optimal efficiency. In addition, quinoxaline photoinitiating system is useful in lithography. Based on the above results, we furtherly developed four visible photoinitiators of cut-off around 530nm. They have different performance in initiating PPGDA and AMP-10G respectively in terms of polymerization rate. However, from the viewpoint of the degree of monomer conversion, BenQs are better than PMQs.