| abstract |
Acid stable borates for light curing. Compounds of formula I: wherein R {sub, 1 is, for example, alkyl of 1 to 20 carbon atoms or phenylalkyl of 1 to 6 carbon atoms, the radicals of which are unsubstituted or substituted; R {sub, 2, R {sub, 3, and R {sub, 4, independently of each other are phenyl or biphenyl, the radicals of which are unsubstituted or substituted where the sum of the constants {or Hammett ({S { sub, {o) of the substituents on the aromatic radicals R {sub, 2, R {sub, 3, and R {sub, 4 is between +0.36 and +2.58; R {sub, 8, R {sub, 9, R {sub, 14, R {sub, 15, and R {sub, 16 are, for example, alkyl of 1 to 12 carbon atoms, phenylalkyl of 1 to 6 atoms carbon, or phenyl, and G is a radical that can form positive ions, are suitable as photoinitiators for photopolymerizable compositions containing acid groups, in the presence of a co-initiator if desired. |