摘要 |
A positive-working lithographic printing plate which is imageable by dual infrared lasers has a substrate which absorbs modulated, imaging infrared laser radiation of one wavelength to heat the substrate and an adjacent coating. The substrate has a coating which is a material which will react and form gaseous reaction products which ablate or propel the coating from the substrate upon reaching a threshold reaction temperature. The coating is transparent to the infrared radiation of the one wavelength and contains a dye which absorbs unmodulated, non-imaging infrared laser radiation of another wavelength to heat the coatng. The unmodulated, non-imaging infrared laser radiation heats the coating in the imaged areas to a temperature below the threshold temperature and the heat from the substrate further heats the coating to a temperature above the threshold temperature and ablates the coating in the imaged areas.
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