Photopolymerizable composition with acylphosphine sulfide photoinitiator and method

Claim 1

A process for the preparation of a photopolymerizable composition which comprises: incorporating a photoinitiator into a photopolymerizable composition containing monomers having polymerizable C--C double bonds, said photoinitiator being an acylphosphine sulfide of the formula ##STR12## where R 1 is straight-chain or branched alkyl of 1 to 6 carbon atoms, cyclohexyl or cyclopentyl, or a phenyl, naphthyl or O--, S-- or N--containing 5- or 6-membered heterocyclic radical which is unsubstituted or substituted by fluorine, chlorine, bromine, C 1 -C 4 --alkyl or C 1 -C 4 --alkoxy; R 2 has the meanings of R 1 and can be identical to or different from R 1 , or is alkoxy of 1 to 6 carbon atoms, phenoxy which is unsubstituted or substituted by chlorine, C 1 -C 6 --alkyl or C 1 -C 6 --alkoxy, or phenoxyalkyl, where alkyl is of 1 to 4 carbon atoms, or R 1 and R 2 are linked together to form a ring of 4 to 10 carbon atoms which is unsubstituted or can contain 1 to 6 further alkyl substituents, each of 1 to 4 carbon atoms, as well as 1 or 2 fused-on benzene rings; R 3 is straight-chain or branched alkyl of 2 to 18 carbon atoms, a cycloaliphatic radical of 3 to 12 carbon atoms, mono-, di-, tri- or tetra-substituted phenyl or an unsubstituted or mono-, di-, tri- or tetra-substituted naphthyl, where the substituents can be identical or different and can be alkyl, alkylthio or alkoxy of 1 to 6 carbon atoms or chlorine, bromine or fluorine, or the group ##STR13## where R 1 and R 2 have the above meanings and X is unsubstituted or mono-, di-, tri- or tetra-substituted phenylene, where the substituents can be identical or different and can be alkyl, alkylthio or alkoxy of 1 to 6 carbon atoms or halogen of atomic weight of not more than 80, or X is an aliphatic or cycloaliphatic divalent radical of 2 to 6 carbon atoms; and where one or more of R 1 , R 2 and R 3 may be olefinically unsaturated, where R 3 can also be methyl or phenyl.