Photoinitiators for photopolymerizable coating compositions

Claim 1

A photopolymerizable coating composition which contains, as the binder, an olefinically unsaturated compound of boiling point above 50° C., together with from 0.5 to 15 percent by weight of a photoinitiator, based on the binder, the photoinitiator comprising a mixture of: (A) an aromatic carbonyl compound of the formula ##STR6## (B) an aromatic carbonyl compound of the formula ##STR7## and (C) an amine of the formula ##STR8## wherein in formulae I, II and III, R 1 is H, Cl, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms or alkoxyalkyl of 2 to 4 carbon atoms, R 2 is H, Cl or R 1 -phenyl, and if (a) R 2 is H or Cl, R 3 and R 4 are H, Cl, alkyl of 1 to 4 carbon atoms or R 1 -phenyl, while (b) if R 2 is R 1 -phenyl, R 3 is alkoxy of 1 to 7 carbon atoms and R 4 is R 3 , H, alkyl of 1 to 4 carbon atoms or CH 2 OH, or R 3 and R 4 conjointly are a O--C n --H 2n --O bridge, where n is an integer from 2 to 8, R 5 and R 6 are H, alkyl of 1 to 5 carbon atoms, alkoxy of 2 to 5 carbon atoms, COOH, COOR 7 or COON(R 7 ) 2 (where R 7 is alkyl of 1 to 7 carbon atoms), Cl or chloroalkyl of 1 to 3 carbon atoms, X is H, a direct bond or an O, CO, S, NH or NR 8 bridge (where R 8 is alkyl of 1 to 5 carbon atoms), and R', r" and R"' are H, alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 10 carbon atoms, aryl, hydroxyalkyl of 1 to 8 carbon atoms or alkoxyalkyl of 2 to 4 carbon atoms, with the proviso that at most 2 substituents are H and at most 2 substituents are aromatic.