| abstract |
The invention relates to compounds of formula I or I '(CF DRAWING IN BOPI) wherein each of R1 and R2 is independently, for example, an aromatic hydrocarbon radical which is substituted at least at one ortho position, or an alkyl radical in C1 -C20 substituted with R9 R10 R11 Si; R2a is, for example, a divalent aromatic hydrocarbon radical; R3 is a C1 -C20 alkyl radical substituted with R9 R10 R11 Si or is an aromatic hydrocarbon radical; R4 is, for example, a C1 -C20 alkyl, C3 -C12 cycloalkyl or phenyl (C1 -C4 alkyl) radical; E is R14 R15 R16 P or R8 R8a R7 N; each of R7, R8 and R8a and of R9, R10 and R11 is independently, for example, a C1 -C4 alkyl group; each of R14, R15 and R16 is independently a substituted phenyl radical; and G is a radical which is capable of forming positive ions, provided that if R1, R2 and R3 are 2,4,6-trimethylphenyl radicals, R4 is not a C2 -C20 alkyl or C2- alkenyl radical C8. These compounds can be used as very reactive photoinitiators. Application to photosensitive materials. |