Photoactive resins, radiation curable compositions and radiation curable inks

A photoactive resin for improving cure properties of radiation curable compositions and inks, said resin comprising:

• an aromatic ketone including a biphenyl moiety;
• and
• a chain ending group selected from hydrogen, a methylol group and mixtures thereof;
• wherein the resin has the Formula I:
• wherein
• R1 is selected front hydrogen, a branched alkyl radical having 1 to 12 carbon atoms, an unbranched alkyl radical having 1 to 12 carbon atoms, a branched aromatic radical having 1 to 12 carbon atoms, and an unbranched aromatic radical having 1 to 12 carbon atoms,
• R2 is selected from hydrogen, a branched alkyl radical having 1 to 12 carbon atoms, an unbranched alkyl radical having 1 to 12 carbon atoms, a branched aromatic radical having 1 to 12 carbon atoms, and an unbranched aromatic radical having 1 to 12 carbon atoms,
• R3 is selected from an substituted, bridged, aromatic radical having 1 to 20 carbon atoms, a substituted, unbridged, aromatic radical having 1 to 20 carbon atoms, an unsubstituted, bridged, aromatic radical having 1 to 20 carbon atoms, an unsubstituted, unbridged, aromatic radical having 1 to 20 carbon atoms, a substituted, bridged, aliphatic radical having 1 to 20 carbon atoms, a substituted, unbridged, aliphatic radical having 1 to 20 carbon atoms, an unsubstituted, bridged, aliphatic radical having 1 to 20 carbon atoms, and an unsubstituted, unbridged, aliphatic radical having 1 to 20 carbon atoms,
• Y is said chain ending group selected from hydrogen, a methylol group and mixtures thereof,
• m is an integer from 0-50,
• n is an integer from 1-50, and
• o is an integer from 0-2.