Aminoketone sensitizers for photopolymer compositions

Abstract

Aminoketone-substituted coumarin sensitizers having tethered tertiary amino groups are described which have extremely good photosensitivity. The sensitizers of the instant invention have the formula: ##STR1## wherein R.sub.1 and R.sub.2 each represent an alkyl group having 1 to 6 carbon atoms, and R.sub.3 and R.sub.4 each represent hydrogen; or at least one of R.sub.1 and R.sub.3 or R.sub.2 and R.sub.4 together represent an alkylene group having 2 to 4 carbon atoms, R.sub.5 represents an alkyl group having 1 to 6 carbon atoms or H, R.sub.6 represents an alkylene group having 1 to 6 carbon atoms, and R.sub.7 and R.sub.8 each independently represent an alkyl group having 1 to 6 carbon atoms, both of R.sub.7 and R.sub.8 taken together represent an alkylene group having 4 to 6 carbon atoms, or R.sub.5 or R.sub.6 taken together with R.sub.7 or R.sub.8 represent a five, six, or seven membered heterocyclic ring group. Photopolymer compositions comprising a free-radically polymerizable material, a photoinitiator, and an aminoketone-substituted coumarin sensitizer, are also disclosed.

Dependencies are inferred from the claim text.