Polymeric dyes, overcoat compositions and thermal lithographic printing plates
AssigneeAmerican Dye Source, Inc.
InventorsMy T. Nguyen, Marc-Andre Locas
Life of this patent
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Abstract
A thermal lithographic printing plate overcoat composition comprising (a) a water-soluble polymeric dye having an absorption band between about 300 and about 600 nm; and (b) micro-particles or nano-particles is provided. A negative-working thermal lithographic printing plate comprising (a) a hydrophilic substrate; (b) a near infrared imaging layer disposed on the hydrophilic substrate; and (c) an overcoat layer disposed on the imaging layer, said overcoat layer comprising a water-soluble polymeric dye having an absorption band between about 300 and about 600 nm; and micro-particles or nano-particles is also provided. Finally, a water-soluble polymeric dye having an absorption band between about 300 and about 600 nm is provided.
Claims18
A thermal lithographic printing plate overcoat composition comprising:
- (a) a water-soluble polymeric dye having an absorption peak within a range between about 300 and about 600 nm;
- and
- (b) micro-particles or nano-particles,
- wherein the overcoat composition is transparent to near infrared radiation and
- wherein said polymeric dye is of formula:
- wherein a and c independently vary between about 0.05 and about 0.95;
- b varies between about 0.00 and about 0.50;
- d varies between about 0.02 and about 0.20, R represents hydrogen or methyl;
- R1 represents hydrogen, hydroxy, alkoxy, alkyl, halide, or carboxylic acid;
- M represents carboxylic acid, 1-imidazole, 2-pyrrolidone, a polyethylene oxide chain, sulfonic acid or phosphoric acid;
- and Q1, Q2, Q3 and Q4 are the same or different and represent a chromophore having said absorption peak.
Dependencies are inferred from the claim text.