Reworkable UV curing materials

Novel UV curing materials which became soluble in solvents by photo/thermal degradation were studied. Three types of systems were designed and prepared, i.e. (a) base polymer/crosslinker blended system, (b) functionalized polymer system, and (c) multifunctional acrylate monomer system. In the base polymer/crosslinker blended system, as a crosslinker, multifunctional epoxy compounds containing tertiary esters of carboxylic acid or sulfonate ester units were synthesized and used in combination with polyvinylphenol. Functionalized polymers bearing epoxy units and thermally degradable linkages in the side chain were prepared. Furthermore, multifunctional methacrylate or acrylate monomers bearing acetal linkages in a molecule were prepared. Photocrosslinking and thermal decrosslinking of those materials were studied.