SYNTHESIS, REACTIVITY, AND PROPERTIES OF NEW DIARYLIODONIUM SALTS AS PHOTOINITIATORS FOR THE CATIONIC POLYMERIZATION OF EPOXY SILICONES

Diaryliodonium tetrakis (pentafluorophenyl) berate salts generate a hi gher reactivity than any other known diaryliodonium salt. The photoche mical properties of diaryliodonium tetrakis (pentafluorophenyl) borate salts were compared to those of the diaryliodonium hexafluoroantimona te salt. The results show that these new salts are the most reactive p hotoinitiators in this family. In addition, diaryliodonium tetrakis (p entafluorophenyl) berate salts are soluble in low polarity media, such as epoxy silicone oils, which are rich in epoxy groups and insensitiv e to humidity. These salts have the advantage not to contain a heavy m etal (such as antimony). The new properties generated by the use of th e tetrakis (pentafluorophenyl) berate anion make the future of the cat ionic photopolymerization promising. (C) 1996 John Wiley & Sons, Inc.