Novel benzyl sulfonium salt having an aromatic group on sulfur atom as a latent thermal initiator

Abstract

Abstract Three benzyl p ‐hydroxyphenyl methylsulfonium salts with different counter anions were synthesized as novel latent thermal initiators. Syntheses of the sulfonium salts ( 2 ) were performed by the reaction of p ‐hydroxyphenyl methyl sulfide with benzyl chloride followed by exchange of the counter anion (Cl − ) with SbF − 6 ( 2a ), PF − 6 ( 2b ), or BF − 4 ( 2c ). In the bulk polymerization of glycidyl phenyl ether (PGE) with 2 , initiator activity of the sulfonium salts was evaluated by comparison with that of benzyl tetramethylenesulfonium hexafluoroantimonate ( 1 , R = H). Among the initiators, 2a showed the highest activity, and was much more active than 1 (R = H). Since the polymerization of PGE with 2a proceeded efficiently at more than 80°C but not at all at less than 60°C, 2a was suggested to be a good latent thermal initiator.