Abstract: Two kinds of sulfonium salts as Photo-acid Generator have been successfully synthesized. Their structures were confirmed by ¹1HNMR and MS. Some physical performances have also been measured. Further, their photo-decomposition and acid-forming performance in acetonitrile under irradiation at 405 and 365 nm were evaluated by the method ascertained in our laboratory. It is found that two sulfonium salts have high thermo-decomposition temperature and good dissolution in some organic solvents. When exposed at 405 nm, the quantum yields of decomposition of 4-(9-phenyl-anthracenyl)phenyl sulfonium salt of methyl trifluoromethanesulfonate (PAGS1) and 4-(4′-(N, N-diethyl)-1′-styrenyl)phenyl sulfonium salt of methyl trifluoromethanesulfonate (PAGS2) were 10% and 15% respectively; their quantum yields of acid-forming were 8.1% and 13% respectively. However, when exposed by 365 nm, their quantum yields of decomposition and acid forming were very low. Finally, it is concluded that both PAGS1 and PAGS2 are sensitive to light at 405 nm and applicable to be used as PAG in Purple Laser CTP technology.

Key words: photo-acid generator, sulfonium salt, quantum yield, image