エポキシ樹脂用潜在性硬化剤としての 光カチオン重合開始剤の構造と特性Ⅰ

抄録

This article reviews the photo cationic polymerization initiator（ or the photo acid generator） as a latent curing agent for epoxy resin. One of the major type photo initiators used in the market is the combination product of triarylsulfonium cation and antimony hexafluoride anion（ SbF₆^-） or phosphrous hexafluoride one （PF₆^-）. The triarylsulfonium structure without substituents on the benzene ring creates drawbacks such as the benzene emission from the film during and after curing, the migration of undesirable material from the cured film, and the nasty odor originated from Sulphur. In order to improve these disadvantages, various modifications of triarylsulfonium salt have been performed including the introduction of substituents on benzene ring and the formation of cyclic structure consisting of triarylsulfonium salt. Another important improvement needed is to heighten the photosensitivity under the light of wavelength longer than 365 nm（ i-line） because of the increasing demand in the precision semiconductor manufacturing industry. The photosensitivity has been improved by incorporating the conjugated photosensitive structure into the triarylsulfonium salt. Taking CAS registration number as identification of the commercially available product, the article focuses mainly on reviewing the chemical structures and properties of above-mentioned triarylsulfonium salts together with the photo-activation mechanism of initiator and the cationic polymerization mechanism of epoxy resin.