| abstract |
Disclosed is a compound of the formula n nwherein R 1 is an alkylene, arylene, arylalkylene, or alkylarylene group, R 2 and R 2 ′ each independently of the other, are alkylene, arylene, arylalkylene, or alklarylene groups, R 3 and R 3 ′ each, independently of the other, are either (a) photoinitiating groups, or (b) groups which are alkyl, aryl, arylalkyl, or alkylaryl groups, provide that at least one of R 3 and R 3 ′ is a photoinitiating group, and X and X′ each, independently of the other, is an oxygen atom or a group of the formula —NR 4 —, wherein R 4 is a hydrogen atom, an alkyl group, an aryl group, or an alkylaryl group. |