| abstract |
The invention relates to photopolymerizable compositions comprising one or more polymerizable ethylenically unsaturated compounds and a photo-initiator system comprising a diketon: A-(C=O)-(C=O)-A (A and A' are aromatic hydrocarbon groups), and a reducing agent N-R 1 R 2 R 3 (R 1 , R 2 and R 3 are hydrogen, hydrocarbon, substituted hydrocarbon or aromatic, at least one R bears an α-H), and is characterized in that 0.001 1 % (wt) of a polyhalogen-containing compound is added to the photo-initiator system, while 0.001 1 % (wt) photo initiator is used. |