Visible light photoinitiating systems using borate salts as coinitiators applied to the laser imaging area

This paper describes the photochemistry of visible light photoinitiating systems (PIS) developed for free radical photopolymerization (FRP). These PIS consist of borate salt used as coinitiators combined with different dyes absorbing the UV-visible range. It was shown, that these systems lead to high rates of polymerization and high conversion degrees. Based on laser flash photolysis (LFP) results, a reaction mechanism was proposed. This mechanism is discussed in terms of photoinduced electron transfer between (PET) and fast dissociation of borate radical.

Keywords: photoinitiating systems, laser flash photolysis, free radical photopolymerization.