CO-INITIATOR COMPOSITIONS FOR PHOTOPOLYMERIZATION CONTAINING 3-ACYL-SUBSTITUTED COUMARINS, PHOTOPOLYMERIZABLE COMPOSITION AND PHOTOGRAPHIC ELEMENT

摘要

Novel co-initiator compositions for use in improved photopolymerizable compositions, photopolymerizable compositions and elements are disclosed. The co-initiator compositions comprise a photopolymerization activator and a 3-keto-substituted coumarin sensitizer which has maximum absorption of radiation between 250 and 550 nm. The coumarin sensitizer has a substituent in the 3-position. R<1> is an aromatic carbocyclic or heterocyclic group conjugated with the carbonyl directly or through an alkenylene group. Particularly useful co-initiator compositions comprise an amine-substituted ketocoumarin and an activator selected from certain amino-derivatives of acetic acid.