| abstract |
The use of photo-initiators of the formula I or II <IMAGE> I <IMAGE> II in which n is 1 or 2, Ar is a monovalent or divalent aromatic radical, X is a tertiary amino group, a hydroxyl or ether group or a siloxy group, R1 and R2 are alkyl, substituted alkyl, alkenyl, cycloalkyl or phenylalkyl or together are alkylene or oxa- or aza-alkylene and R3 is a direct bond or a divalent aliphatic, cycloaliphatic or aromatic radical, in combination with light stabilizers from the category of the polyalkylpiperidine derivatives in the photopolymerization of ethylenically unsaturated compounds results in polymers with high stability to light and low yellowing. |