Novel mixtures based on substituted dialkoxyacetophenones, their use as photoinitiators, and photopolymerisable systems containing such mixtures

摘要

Mixtures of at least one substituted dialkoxyacetophenone of the formula (I) IMAGE in which R1 is an alkyl, alkoxyalkyl, chloroalkyl or alkyl-OCH2CH2OCH2CH2 group, R2 is an alkyl, alkoxy, alkylthio, cycloalkyl or aralkyl group, chlorine, bromine, a further -CO-CH(OR1)2- group or a IMAGE group, X is a direct bond, O or S, R3 is H, Cl, Br or an alkyl, alkoxy, alkoxycarbonyl or a further -CO-CH(OR1)2- group, and of at least one compound from the group consisting of optionally substituted anthraquinones, xanthones, thioxanthones, acridanones, benzoin derivatives, benzil ketal derivatives and/or optionally substituted benzophenones, exhibit a significantly controlled reactivity in their capacity to initiate the photopolymerisation of ethylenically unsaturated compounds or mixtures. The use of these mixtures as photoinitiators in the photopolymerisation of ethylenically unsaturated compounds or mixtures gives polymers which experience only extremely low levels of yellowing.