A direct evaluation method is proposed for UV curing process of photocurable materials. This method is based on the measurement of the conductivity decrease which is caused by the photopolymerization of photocurabler materials. It is able to get various useful information of curing process and curing velocity on the radical generated photopolymerization from applying this direct evaluation method. In this paper we describe the curing process and some mechanistic study of the cationic photopolymerization by this direct evaluation method.
