Barton Esters as New Radical Photoinitiators for Flat Panel Display Applications

Abstract

A new series of photoinitiators for free radical photopolymerization based on Barton ester derivatives is developed for flat panel display applications. The absorption spectra exhibit a broad band between 320 and 420 nm. The photolysis quantum yields are very high, a fact that underlines the capability of the photoinitiators to bleach during the irradiation and thereby to lead to a moderate yellowing. Compared to commercial photoinitiators, the Barton esters display a very good efficiency. As revealed by laser flash photolysis, the dissociation rate constants are very high. Quantum mechanical computations show that the photodissociation can occur from both the excited singlet and triplet states.