Abstract: UV-crosslinkable acrylic hotmelt pressure sensitive adhesives comprising acrylic and vinyl monomers, and a polymerizable UV photoinitiator. The photoinitiator comprises a spacer comprising both ethylene oxide and urethane, or urea, carbonate, or siloxane functional groups. The ethylene oxide is directly bonded to the chromophore (e.g., benzophenone) moiety, while the urethane (or urea, carbonate, siloxane) is closely linked to the polymerizable moiety (e.g., styrenic C?C double bond).

Abstract: The invention is directed to aromatic maleimides as photocrosslinkers for unsaturated compositions. The maleimides utilized are multifunctional, and are attached to a polymeric backbone. As such, they are polymeric or polymer-bound photoinitiators/photocrosslinkers. The polymeric maleimides are necessarily aromatic, but may or may not exhibit substituents at the 3- and 4-position of the maleimide ring. These maleimide photocrosslinkers may be used alone or in conjunction with a photosensitizer to effectively crosslink unsaturated materials.