Photoinitiator resins with dibenzoylmethane substructure

A kit comprising

• a) a reaction product of:
• i) one or more aromatic Michael addition donor materials comprising two or more active methylene hydrogens and at least two optionally substituted benzoyl-moieties;
• wherein the Michael addition donor material is dibenzoylmethane, a substituted dibenzoylmethane derivative, or a combination thereof;
• with
• ii) one or more Michael addition acceptor materials, wherein the Michael addition acceptor material is selected from the group consisting of mono, di-, tri- or multi-functional (meth)acrylates, polyester (meth)acrylates, and halogenated organic acids or esters;
• wherein the reaction product is capable of initiating a free radical polymerization reaction when used in combination with a synergist;
• and
• b) a synergist selected from the group consisting of amines, thiols, and combinations thereof;
• wherein the reaction product a) and the synergist b) are incorporated into a single composition;
• or wherein the reaction product a) and the synergist b) are in separate compositions;
• and wherein each Michael addition donor material-derived moiety present in the reaction product is covalently attached to a single Michael addition acceptor-derived moiety.