Abstract: Compounds of formula (I): {where n is a number from 1 to 6; R3 is hydrogen, methyl or ethyl; A represents a group of formula —[O(CHR2CHR1)a]y—, —[O(CH2)bCO]y—, or —[O(CH2)bCO](y?1)—[O(CHR2CHR1)a]— (where one of R1 and R2 is hydrogen and the other is hydrogen, methyl or ethyl); a is from 1 to 2; b is from 4 to 5; y is from 3 to 10; Q is a residue of a polyhydroxy compound having 2 to 6 hydroxy groups; and x is greater than 1 but no greater than the number of available hydroxyl groups in Q} and esters thereof are useful as photoinitiators for the preparation of energy-curable compositions, such as varnishes and printing inks.

Abstract: A multi-functional photoinitiator of formula (I) R1m—Q—(A1—PI)n??(I) wherein Q is a heteroatom selected from Si, Ti, Zr and Sn or any two independently selected such heteroatoms linked by a covalent bond or a by C1-16 (preferably C1-9) alkylene group, n is at least 2 and n+m=the functionality of Q, each R1 is the same or different and is a non-photoinitiator group; each group PI is the same or different and is a photoinitiator group. Each —A1— is the same or different and is selected from linking groups of formula —(A2)p—Z— wherein p has an average of from 1 to 10, preferably from 3 to 5 and the groups —A2— are either (a) each independently selected from C2-4 alkyleneoxy groups; or (b) each independently selected from groups of formula —O—(CH2)qCO— wherein q is from 3 to 5, and Z is selected from —O—, —S— and —NR6— where R6 is C1-6 alkyl.

Abstract: A multifunctional photoinitiator is obtainable as the reaction product of a multifunctional core material containing two or more reactive groups and a photoinitiator or a derivative thereof. The photoinitiator or its derivative has a reactive group capable of reacting with the reactive groups of the multifunctional core.