Photolysis of hexaarylbiimidazole sensitized by dyes and application in photopolymerization

Kinetic studies on the near-UV photo-initiating polymerization of methylmet hacrylate (MMA) sensitized by dye/hexaarylbiimidazole systems were carried out. When exposed to high-pressure mercury lamp (filtered by Pyrex glass), dye/hexaarylbiimidazole system undergoes quick electron transfer and free r adicals are produced. RSH, as hydrogen donor, can improve the polymerizatio n efficiency of MMA. Comparisons of influence of different dyes and differe nt RSH on the conversion of MMA photopolymerization were carried out. Excel lent results have been obtained in photoimaging studies, e. g. a minimum ex posure energy of the photosensitive systems of 8 mJ/cm(2) can be reached an d the resolution of presensitized printing plate was ca. 10 mu m.