Photopolymerizable composition containing a photosensitive donor and photoinitiating acceptor

摘要

Disclosed is a photopolymerizable vehicle and method for the selective photopolymerization of said vehicle by the application of a plurality of different selected wavelengths of energy wherein any single wavelength of energy is inadequate for effecting said photopolymerization. The method comprises sequentially applying a plurality of different selected wavelengths of energy to said vehicle whereby polymerization is effected at the intersection of said wavelengths of energy. The photopolymerizable vehicle comprises: (a) a medium selected from photopolymerizable ethylenically unsaturated monomers, oligomers, prepolymers, or mixtures thereof; (b) a photosensitive donor responsive to first selective wavelengths of energy for generating primary excited-state donor molecules which are not responsive to said first selected wavelengths of energy, but are responsive to sequentially applied second selective wavelengths of energy for generating secondary higher energy level excited-state donor molecules; and (c) a photoinitiating acceptor having a ground energy state below said primary donor energy state and a lowest primary excited state at least about 5 kcal/mole greater than said primary excited state of said donor, said secondary higher energy level excited state donor molecules being at least about 5 kcal/mole greater than said lowest primary excited state of said acceptor and transferring energy to said acceptor for initiating photopolymerization of said vehicle. Wavelengths of energy for effecting the selective photopolymerization preferably are generated by lasers.