Abstract: Compounds of formula (I) are photoinitiators or photosensitizers in a photopolymerizable composition: R1 represents a monovalent, linear, branched or cyclic, aliphatic hydrocarbon group having 1 to 20 carbon atoms, optionally substituted with substituent(s) selected from —Cl, —Br, —OH, ?O, —NH—CO—OR2, —NH—CO—R2 or free-radically or ionically polymerizable groups. Each R2 is independently —H or C1-6 alkyl; n is ?1. If n=1, Z and Y are absent and X represents —OR3; if n is >1, Z represents —OR4—, Y represents —OR5— and X represents —H or —OH. R3 represents —H or R1; and R4 and R5 each independently represent a bivalent hydrocarbon group. The polymerizable moieties as optional substituents of R1 are polymerizable double or triple bonds, lactam, lactone and epoxide moieties, which are subjectable to ring-opening polymerization; and two of R1 to R5 may be linked to one another to form a ring or a dimer.

Abstract: Compounds of formula (I) are photoinitiators or photosensitizers in a photopolymerizable composition: R1 represents a monovalent, linear, branched or cyclic, aliphatic hydrocarbon group having 1 to 20 carbon atoms, optionally substituted with substituent(s) selected from —Cl, —Br, —OH, ?O, —NH—CO— OR2, —NH—CO—R2 or free-radically or ionically polymerizable groups. Each R2 is independently —H or C1-6 alkyl; n is ?1. If n=1, Z and Y are absent and X represents —OR3; if n is >1, Z represents —OR4—, Y represents —ORs— and X represents —H or —OH. R3 represents —H or R1; and R4 and R5 each independently represent a bivalent hydrocarbon group. The polymerizable moieties as optional substituents of R1 are polymerizable double or triple bonds, lactam, lactone and epoxide moieties, which are subjectable to ring-opening polymerization; and two of R1 to R5 may be linked to one another to form a ring or a dimer.

Abstract: Compounds of formula (I) are photoinitiators or photosensitizers in a photopolymerizable composition: R1 represents a monovalent, linear, branched or cyclic, aliphatic hydrocarbon group having 1 to 20 carbon atoms, optionally substituted with substituent(s) selected from —Cl, —Br, —OH, ?O, —NH—CO—OR2, —NH—CO—R2 or free-radically or ionically polymerizable groups. Each R2 is independently —H or C1-6 alkyl; n is ?1. If n=1, Z and Y are absent and X represents —OR3; if n is >1, Z represents —OR4—, Y represents —OR5— and X represents —H or —OH. R3 represents —H or R1; and R4 and R5 each independently represent a bivalent hydrocarbon group. The polymerizable moieties as optional substituents of R1 are polymerizable double or triple bonds, lactam, lactone and epoxide moieties, which are subjectable to ring-opening polymerization; and two of R1 to R5 may be linked to one another to form a ring or a dimer.

Abstract: Compounds of formula (I) are photoinitiators or photosensitizers in a photopolymerizable composition: R1 represents a monovalent, linear, branched or cyclic, aliphatic hydrocarbon group having 1 to 20 carbon atoms, optionally substituted with substituent(s) selected from —Cl, —Br, —OH, ?O, —NH—CO— OR2, —NH—CO—R2 or free-radically or ionically polymerizable groups. Each R2 is independently —H or C1-6 alkyl; n is ?1. If n=1, Z and Y are absent and X represents —OR3; if n is >1, Z represents —OR4—, Y represents —ORs— and X represents —H or —OH. R3 represents —H or R1; and R4 and R5 each independently represent a bivalent hydrocarbon group. The polymerizable moieties as optional substituents of R1 are polymerizable double or triple bonds, lactam, lactone and epoxide moieties, which are subjectable to ring-opening polymerization; and two of R1 to R5 may be linked to one another to form a ring or a dimer.