Abstract: Plates such as those used in lithographic printing and photoresists such as those used in preparing printed circuit boards and the like are provided with a photopolymerizable photosensitive diazo resin that is unusually stable. The diazo resin is laid down from a stabilized diazonium composition that is an emulsion including the selected diazo resin, a purine derivative, especially a theophylline derivative, preferably in combination with a salt of a low molecular weight alkyl sulfonic acid or other supplementary stabilizer component.

Abstract: A photopolymerizable coating over a diazo resin provides a high-speed lithographic plate or photoresist while improving the printing life of the plate while making its development simpler than that of most other photopolymer plates. The photopolymer is a cinnamoylated resin which is placed over a diazo based material.

Abstract: Finisher and preserver compositions are provided for desensitizing the non-image areas and protecting the image areas of lithographic plates of either the additive or the subtractive type that utilize substantially any type of exposure chemistry, the composition being useful for hand or machine finishing: they are also low in viscosity, are themselves unusually stable, preserve exposed plates for extended periods of storage time, and eliminate streaking on the plate to which they are applied to thereby substantially eliminate blinding problems during printing. Included in the finisher and preserver composition, which is a single phase aqueous system, are specific ratios of a blend of natural gum and synthetic hydrophilic resins, a preservative for the natural gum resin, a buffer system of phosphate and phosphoric acid, and a surfactant, with the balance being substantially entirely water.

Abstract: A composition is provided which cleans, conditions, removes scratches, and finishes lithographic plates, the composition being an emulsion of an aqueous phase in an oil phase, the oil phase including a highly penetrating solvent such as mineral spirits, an oleophilic acid, and an emulsifying surfactant such as a non-ionic benzene sulfonate, while the aqueous phase includes a hydrophilic synthetic desensitizer such as a modified polyacrylamide, a gum desensitizer, a desensitizing agent such as phosphoric acid or derivatives thereof, a nitrate salt, and water. These compositions perform as plate cleaners, conditioners and scratch removers when put to use in the press room, and also are typically suitable for use as finishers for exposed and developed plates within the plate making room.

Abstract: A single-phase, non-emulsion water containing subtractive developer for lithographic plates having photopolymer coatings is provided. These developers include water and an active or primary solvent which is only partially soluble in water and which is a good solvent for the photopolymer of a lithographic plate that has not been exposed to and insolubilized by actinic radiation, this active solvent typically being present at a concentration near its water solubility limit. Preferably, a cosolvent is also included to increase the water solubility of the active solvent when necessary. A desensitizer may be included to impart to the formulation the properties of a one-step developer or of a finisher. Formulation and development methods for these developers are also included, and they may be used either as developers or as a machine developer solution replenisher.

Abstract: Presensitized lithographic plates having a diazo layer are prepared such that they exhibit a photospeed rendering them suitable for ultra high speed operations including use within laser platemaking systems. These ultra high speed plates have a diazo layer that is exceedingly thin while still being generally uniformly distributed throughout the plate area. The process includes extracting a significant quantity of diazonium compound or diazonium resin from a diazo layer on a presensitized plate substrate. Plates thus formed are useful in laser exposures for facsimile transmissions, as projection plates, as camera back plates, for step and repeat plate work, and where low intensity light sources are used in conjunction with very large plates.

Abstract: A photopolymerizable coating over a diazo resin provides a high-speed lithographic plate or photoresist while improving the printing life of the plate while making its development simpler than that of most other photopolymer plates. The photopolymer is a cinnamoylated polyvinyl alcohol resin which is placed over a diazo based material.

Abstract: A photopolymerizable system is provided as a latex system that is an oil-in-water polymer emulsion including particulates of water-insoluble polymers in combination with a water-soluble or water-dispersible, light-sensitive polymer having multiple light-sensitive moieties. Prior to coating onto a substrate, the system is a three-phase precursor emulsion of the emulsion particulates, the water phase, and the light-sensitive polymer. After coating, the bulk of the water phase is evaporated off, leaving a two-phase system of the emulsion particulates surrounded by the light-sensitive polymer. When selected areas are subjected to actinic radiation, a water-insoluble matrix is formed, the matrix containing cross-linked light-sensitive polymer having dispersed therethrough and/or included therein the water-insoluble polymer particulates, thus forming oleophilic image areas.

Abstract: Presensitized lithographic plates having a diazo layer are prepared such that they exhibit a photospeed rendering them suitable for ultra high speed operations including use within laser platemaking systems. These ultra high speed plates have a diazo layer that is exceedingly thin while still being generally uniformly distributed throughout the plate area. The process includes extracting a significant quantity of diazonuim compound or diazonium resin from a diazo layer on a presensitized plate substrate. Plates thus formed are useful in laser exposures for facsimile transmissions, as projection plates, as camera back plates, for step and repeat plate work, and where low intensity light sources are used in conjuction with very large plates.

Abstract: A photopolymerizable system is provided as a latex system that is an oil-in-water polymer emulsion including particulates of water-insoluble polymers in combination with a water-soluble or water-dispersible, light-sensitive polymer having multiple light-sensitive moieties. Prior to coating onto a substrate, the system is a three-phase precursor emulsion of the emulsion particulates, the water phase, and the light-sensitive polymer. After coating, the bulk of the water phase is evaporated off, leaving a two-phase system of the emulsion particulates surrounded by the light-sensitive polymer. When selected areas are subjected to actinic radiation, a water-insoluble matrix is formed, the matrix containing cross-linked light-sensitive polymer having dispersed therethrough and/or included therein the water-soluble polymer particulates, thus forming oleophilic image areas.

Abstract: A photopolymerizable system is provided as a latex system that is an oil-in-water polymer emulsion including particulates of water-insoluble polymers in combination with a water-soluble or water-dispersible, light-sensitive polymer having multiple light-sensitive moieties. Prior to coating onto a substrate, the system is a three-phase precursor emulsion of the emulsion particulates, the water phase, and the light-sensitive polymer. After coating, the bulk of the water phase is evaporated off, leaving a two-phase system of the emulsion particulates surrounded by the light-sensitive polymer. When selected areas are subjected to actinic radiation, a water-insoluble matrix is formed, the matrix containing cross-linked light-sensitive polymer having dispersed therethrough and/or included therein the water-insoluble polymer particulates, thus forming oleophilic image areas.