Visible image dyes for positive-acting no-process printing plates
AssigneeMinnesota Mining and Manufacturing Company
InventorsDennis E. Vogel, Robert J. Balchunis, James P. Gardner, George V.D. Tiers, Kim M. Vogel
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Abstract
Positive-acting no-process printing plates are disclosed in which a stable visual or print-out image is obtained upon exposure of the plate to actinic radiation. The visual image is obtained by incorporation into the photosensitive layer, a dye which is irreversibly bleached upon exposure of the printing plate. For example, an acid which is generated upon exposure of a photopolymer to radiation may be used to bleach a dye of this invention. The visual or print-out images produced are useful in the production cycle and are stable to basic environments that may be encountered in the production setting.
Claims29
An article comprising a substrate coated with a photosensitive composition comprising:
- (a) a photoinitiator which generates a strong acid upon exposure to radiation;
- (b) a polymer having acid-labile groups pendant from the polymer backbone;
- and (c) a dye capable of being irreversibly bleached by said acid, providing a visible image upon exposure to radiation.
A process for forming a visible image on an article comprising the steps of (a) providing a substrate coated with a photosensitive composition comprising:
- (1) a photoinitiator which generates a strong acid upon exposure to radiation;
- (2) a polymer having acid-labile groups pendant from the polymer backbone;
- and (3) a dye capable of being irreversibly bleached by said acid;
- and (b) irradiating said article, thereby providing a visible image.
Dependencies are inferred from the claim text.