New Cationic Uv Curing System Applied Research

The UV curing process is a new "Green Technology". The great advantages of UV system are rapid curing speed, high quality coating performance, environmental friendly and low energy consumption. But the inhibition of the oxygen is always a problem for this UV curing technology. While the cationic UV curing process doesn't have this issue, it brings substantial cost and processing advantages as compared to the competitive UV cure methods based on free radical curing, this new UV curing process will also help on the lower volume shrinkage and better adhesion to the kinds of substrates. In this paper, it was studied that the curing and applications of a novel kind of diaryliodonium salt.Iodonium salts are the most important cationic photoinitiators with efficient photopolymerization. In this paper, [4-(2-hydroxy-3-butoxy-1-propoxy) phenyl]-phenyliodonium hexafluoroantimonate (BPI·SbF6) was studied as the typical catiinic UV agent. Firstly the UV curing process with epoxy resin by BPI·SbF6 system was tested. The curing percentage and properties in different curing phases, also the final cured products properties were studied. At same time, the influence to the coating performance by different curing time was tested and compared with other UV curing system. The results proved BPI·SbF6 had very high reaction ability. Then, two formulations were designed based on this BPI·SbF6 UV system as the optical adhesive and comformal coating applications in electronic industry. For adhesive formulation in touch panel, different components of epoxy resin and active dilution were studied. The curing speed, transmittance, shrinkage, lab shear, also the reliability were compared with other UV products. The results showed these formulations had better performance. For comformal coating formulation, different mixed system with acrylic polymer was designed and the difference of coating performance were tested. Also based on the requirement of electronic industry, the insulation properties, the adhesion to the PCB and the salt fog resistance were tested. The results showed this UV system had very good reliability and fit the electronic protection standards.