Synthesis, reactivity, and properties of new diaryliodonium salts as photoinitiators for the cationic polymerization of epoxy silicones

Abstract

SYNOPSISDiaryliodonium tetrakis (pentafluorophenyl) borate salts generate a higher reactivity than any other known diaryliodonium salt. The photochemical properties of diaryliodonium tetrakis (pentafluorophenyl) borate salts were compared to those of the diaryliodonium hexafluoroantimonate salt. The results show that these new salts are the most reactive photoinitiators in this family. In addition, diaryliodonium tetrakis (pentafluorophenyl) borate salts are soluble in low polarity media, such as epoxy silicone oils, which are rich in epoxy groups and insensitive to humidity. These salts have the advantage not to contain a heavy metal (such as antimony). The new properties generated by the use of the tetrakis (pentafluorophenyl) borate anion make the future of the cationic photopolymerization promising. 0 1996 John Wiley & Sons, Inc.

Cationic polymerization using mixed cationic photoinitiator systems

“…10b) shows three distinct SEC peaks (at 37.1, 40.5 and 41.7 min; PS equivalent MW of 1217, 283 and 177 g/mol, respectively) after the photolysis. This is the number of distinct sizes of species expected from the photolysis mechanism for this diaryl-iodonium salt [15]:…”

Relative Photoactivities of Iodonium Tetrakis(pentafluorophenyl)gallates Measured by Fluorescence Probe Techniques

“…(4-Octyloxyphenyl)-phenyliodonium tetrakis(pentafluorophenyl)borate (2e), (4-isopropylphenyl)-4-methylphenyliodonium hexafluoroantimonate (3b), and (4-isopropylphenyl)-4-methylphenyliodonium choloride (4b) were prepared as described previously. 5,20 All of iodonium tetrakis(pentafluorophenyl)gallates were prepared according to procedures reported in another paper. 2 Epoxy silicone oligomer UV 9315 (I) was supplied by GE Silicones.…”

“…Epoxy silicone resins of low polarity, especially, are used in release coatings for pressure-sensitive adhesives. 3 When we investigated the performance of such iodonium gallates ( Figure 1) in epoxy silicone resins by routine FTIR, 4,5 the kinetics of their polymerization could not be monitored since the IR band of the epoxy group overlapped with that of the siloxane functions, causing the usual FTIR method to be insensitive. In addition, the FTIR method also has other limitations that limit film thickness and the transmission of the substrates.…”

High Performance Holographic Polymer Dispersed Liquid Crystal Systems Formed with the Siloxane-containing Derivatives and Their Applications on Electro-optics

“…Photo-sensitizer (PS) and photo-initiator (PI) having sensitivity to visible wavelength of Nd-YAG laser (λ= 532 nm) selected for this study are 3, 3'-carbonylbis(7-diethylaminocoumarin) (KC, Kodak) and diphenyliodonium hexafluorophosphate (DPI, AVOCADO research chemicals Ltd.), respectively, which produce both cationic and radical species [43][44][45]. The concentrations of the PS and PI were changed in the range of 0.2-0.4 and 2.0-3.0 wt % to matrix components, respectively.…”