PHOTOPOLYMERIZATION INITIATOR FOR CATIONIC CURING CONTAINING URETHANE GROUP

摘要

PROBLEM TO BE SOLVED: To provide an iodonium salt useful as a photopolymerization initiator having decreased crystallization tendency, improved compatibility especially with an epoxy-containing organopolysiloxane and stable against hydrolysis in storage. SOLUTION: The objective iodonium salt is expressed by the general formula IV, [R1-I-R2]+X- [X- is a complex metal salt and/or strong acid anion; R1 is a univalent aromatic hydrocarbon group having a substituent containing a urethane-group; and R2 is a univalent aromatic hydrocarbon having a substituent] such as the formula VI.