Imaging by Photopolymerization

Photopolymerization is a photochemically-initiated combination of many small monomer molecules which form long polymer chains by means of a chain reaction. The general aspects of these reactions include light-induced formation of reactive-free radicals, initiation of polymerization by these radicals, chain propagation and termination. Inhibition, chain transfer and crosslinking reactions are reviewed. Improvement of the photographic speed, a necessity for many photographic applications, can be secured in two ways: by increasing the amount of polymer formed per incident photon and by enhancing the visibility of the polymer which is obtained. The two essential components of a photopolymer system are the monomers and the photocatalyst system which initiates polymerization in response to the absorption of light. These reactants are combined in a solvent, gel or other suitable medium with other components that may be necessary for specific applications of the system. The effects of each component, plus the effects of inhibitors on the efficiency of polymer formation, are discussed. Once the photopolymer image is formed, it must be prepared for viewing or projection; this consists of rendering the unexposed areas of the composition insensitive to light and possibly augmenting the contrast between the exposed and unexposed areas. General photographic use seems to be theoretically possible, although considerable further development is required.

Print ISSN

0361-4573

Published

1968-11

Content type

Original Research

DOI

10.5594/J10921