Chemical imaging of a lithographic printing plate
AssigneeMaxryan Enterprises, Inc.
InventorsAlbert S. Deutsch, Bruce R. Harrison
Life of this patent
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Abstract
A process for imaging a lithographic printing plate having a coating containing diazo resins. An ink jet printer is used to apply micro drops of a basic chemical solution that insolubilizes the affected areas of the coating to a developing solution. The latent image may be cured by heating the plate for a short period, and is then developed. The process works with conventional, commercially available lithographic plates and developers.
Claims25
A process for imaging a printing plate having a coating comprising diazo compounds, comprising the step of applying imagewise an insolubilizing chemical to the coating.
A printing plate, comprising:
- (a) a substrate having a coated surface comprising diazo compounds and characterized by an effective pH, and
- (b) on part of the coated surface, a latent image defined by a region of higher effective pH.
A printing plate, comprising:
- (a) an aluminum substrate having a surface,
- (b) on the surface, a coating comprising diazo resins and wherein the coating is characterized by an effective water concentration, and wherein further
- (c) a part of the coating defines an image characterized by a different water concentration.
A printing plate, comprising:
- (a) an aluminum substrate having a surface,
- (b) on the surface, a coating comprising diazo resins wherein the coating is characterized by an effective pH, and wherein further
- (c) a part of the coating defines an image characterized by a higher effective pH.
A printing plate, comprising:
- (a) a substrate having a surface,
- (b) on part of the surface, a coating insoluble in a developer, wherein said insolubility has been imparted by reaction with hydroxyl ions.
A printing plate having a coated surface, comprising
- (a) a substrate having a surface,
- (b) on the surface, a coating comprising diazo compounds,
- (c) wherein the coated surface is characterized by an effective concentration of water, and
- (d) wherein on a part of the coated surface, there is defined a latent image characterized by a region of different effective water concentration.
A computer to plate system, comprising:
- a) a printhead containing a plurality of ink jet nozzles such that the printhead is capable of jetting imagewise a basic solution,
- b) a printing plate having a coated surface containing diazo compounds capable of being imaged by the printhead, and
- c) a developer capable of dissolving the non-imaged coating.
A computer to plate system, comprising:
- (a) an ink jet printer with a printhead capable of imaging printing plates,
- (b) an ink capable of insolubilizing a coating containing diazo compounds,
- (c) a printing plate having a coating comprising diazo compounds.
Dependencies are inferred from the claim text.