Photocrosslinking of Poly(vinylphenol) / Epoxy-containing Fluorene Blends Using Photoacid and Photobase Generators

Photo-induced acid-catalyzed crosslinking systems have been widely studied by many workers 1].
The highly sensitive photocrosslinking materials can be used as negative-type photoresists, coating materials and printing materials. Epoxy/phenolic novolac blends are one of the most useful thermosetting systems which are also known to be cationically or anionically crosslinkable 2, 3.
The crosslinked thermosets have a variety of useful properties, including excellent insulating
characteristics, good adhesive properties and good thermal stability. Photocrossfinking of epoxy/phenolic novolac blends can be accomplished by reactions of epoxides with photoproducts
from initiators. Photoacid generators and photobase generators can be used as initiators for the
photoinduced crosslinking 4, 5.
Polymers having diphenylfluorene unit in the main chain have much attention due to their thermal
stability, high refractive indices, low birefringence, non-flammable and insulation properties 6, 7.
Poly(vinylphenol)(PVP) / epoxy-containing fluorene blends 8, 9] are a candidate for coatings with
good thermal stability and high solvent resistance.
In this paper, we report the photoinduced insolubilization of polymeric materials based on PVP and epoxy-containing fluorene derivatives as a crosslinker. Several types of photoacid and photobase generators were used as an initiator of the photoinduced insolubilization. The thermal and optical properties of the crosslinked materials were investigated. Reaction mechanism of the present system is also discussed.