Radiation-sensitive composition containing a resole resin and a novolac resin and use thereof in lithographic printing plates
AssigneeEastman Kodak Company
InventorsNeil F. Haley, Steven L. Corbiere
Life of this patent
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Abstract
A radiation-sensitive composition especially adapted to prepare a lithographic printing plate that is sensitive to both ultraviolet and infrared radiation and capable of functioning in either a positive-working or negative-working manner is comprised of (1) a resole resin, (2) a novolac resin, (3) a latent Bronsted acid and (4) an infrared absorber. The solubility of the composition in aqueous alkaline developing solution is both reduced in exposed areas and increased in unexposed areas by the steps of imagewise exposure to activating radiation and heating.
Claims21
A radiation-sensitive composition comprising an admixture of (1) a resole resin, (2) a novolac resin, (3) a latent Bronsted acid, and (4) an infrared absorber, in amounts such that imagewise exposure of said composition to activating radiation followed by heating brings about a catalyzed reaction between said resole resin and said novolac resin and renders exposed composition less soluble in aqueous alkaline solution and unexposed composition more soluble in aqueous alkaline solution.
A lithographic printing plate comprising a support and an imaging layer that is sensitive to both ultraviolet and infrared radiation and capable of functioning in either a positive-working or negative-working manner, said imaging layer comprising an admixture of (1) a resole resin, (2) a novolac resin, (3) a latent Bronsted acid and (4) an infrared absorber, in amounts such that imagewise exposure of said imaging layer to activating radiation followed by heating brings about a catalyzed reaction between said resole resin and said novolac resin and renders exposed areas of said imaging layer less soluble in aqueous alkaline solution and unexposed areas of said imaging layer more soluble in aqueous alkaline solution.
Dependencies are inferred from the claim text.