Abstract: A method of processing imageable elements useful as alkaline-developable lithographic printing plate precursors that does not require either a rinsing step or a further gumming step is disclosed. The method comprises simultaneously developing and gumming the imaged element with an aqueous alkaline developing-gumming solution comprising one or more water-soluble polyhydroxy compounds of the following structure: R1(CHOH)nR2 in which n is 4 to 7; and either (i) R1 is hydrogen, aryl, or CH2OH; and R2 is hydrogen, alkyl group having 1 to 4 carbon atoms, CH2OR3 in which R3 is hydrogen or an alkyl group having 1 to 4 carbon atoms, CH2N(R4R5) in which R4 and R5 are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, or CO2H, or (ii) R1 and R2 together form a carbon—carbon single bond.

Abstract: An aqueous developer for lithographic printing plates and a method for developing the printing plates are disclosed. The developer comprises an organic dispersing agent. The developer develops multi-layer printing plates quickly, with high throughput, but with no sludge formation in the developing process.

Abstract: A method and an apparatus for the refreshment and reuse of loaded developers used in lithographic printing are disclosed. The pH of an aqueous, essentially silicate-free loaded developer is reduced to below about 11. Insoluble material is separated, and the pH increased to about 12.0 to 14.0 to produce a refreshed developer. The refreshed developer may be used to develop additional exposed printing plate precursors.

Abstract: An aqueous alkaline developing system for alkaline-developable lithographic printing plates and a method for its use are disclosed. The developing system comprises one or more water-soluble suppressors of the following structure: R1(CHOH)nR2 in which: n is 4 to 7; and either (i) R1 is hydrogen, aryl, or CH2OH; and R2 is alkyl group having 1 to 4 carbon atoms, CH2OR3 in which R3 is an alkyl group having 1 to 4 carbon atoms, CH2N(R4R5) in which R4 and R5 are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, or CO2H; or (ii) R1 and R2 together form a carbon—carbon single bond. The developing system is especially suited for developing imageable elements useful as lithographic printing plates. The developing system is especially suited for use with elements in which (1) the imageable layer comprises at least one phenolic resin or at least one polymeric compound having pendent sulfonamide groups, and (2) the substrate is aluminum or and an aluminum alloy.

Abstract: Positive-working imageable elements and methods for their preparation are disclosed. The elements comprise a hydrophilic substrate; a bottom layer, which contains a positive-working photosensitive composition; and a protective overlayer, which has an overlayer material that reduces the solubility of the photosensitive composition in an aqueous alkaline developer. The overlayer may be conveniently applied by a dip and rinse procedure.

Abstract: An aqueous alkaline developing system for alkaline-developable lithographic printing plates and a method for its use are disclosed.

Abstract: A replenisher composition developing exposed radiation-sensitive printing plate precursors for plate/developer systems in which the electrical conductivity of the developer does not decrease to the same extend as the activity of the developer decreases or even increases is disclosed. A method for developing exposed radiation-sensitive printing plates using the replenisher composition is also disclosed.

Abstract: A method for the refreshment and reuse of loaded developers used in lithographic printing is disclosed. A polyoxyalkylene derivative is added to a silicate-containing loaded developer. Insoluble material is separated and the alkalinity level of the resulting essentially colorless liquid adjusted to produce a refreshed developer. The refreshed developer may be used to develop additional exposed imageable elements.

Abstract: A method for developing exposed lithographic printing plate precursors using a developer and replenisher is disclosed. The replenisher contains a higher concentration of a coating attack-suppressing agent than the developer, so that the aggressiveness of the developer remains substantially constant during the developer loading cycle.

Abstract: A replenisher composition developing exposed radiation-sensitive printing plate precursors for plate/developer systems in which the electrical conductivity of the developer does not decrease to the same extend as the activity of the developer decreases or even increases is disclosed. A method for developing exposed radiation-sensitive printing plates using the replenisher composition is also disclosed.

Abstract: Additive compositions suitable for rinse water used for processing lithographic printing plates, particularly to additive compositions for rinse water in water recycling systems, are disclosed. The additive compositions contain at least one water-soluble film-forming polymer; optionally, at least one pH regulating agent capable of maintaining the pH value of an aqueous solution at about 7 or below; and at least one compound selected from the group consisting of phosphonic acid derivatives of formula I.

Abstract: An aqueous alkaline developing system for alkaline-developable lithographic printing plates and a method for its use are disclosed. The developing system comprises one or more water-soluble suppressors of the following structure: R1 (CHOH)nR2 in which: n is 4 to 7; and either (i) R1 is hydrogen, aryl, or CH2OH; and R2 is alkyl group having 1 to 4 carbon atoms, CH2OR3 in which R3 is an alkyl group having 1 to 4 carbon atoms, CH2N(R4R5) in which R4 and R5 are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, or CO2H; or (ii) R1 and R2 together form a carbon-carbon single bond. The developing system is especially suited for developing imageable elements useful as lithographic printing plates. The developing system is especially suited for use with elements in which (1) the imageable layer comprises at least one phenolic resin or at least one polymeric compound having pendent sulfonamide groups, and (2) the substrate is aluminum or and an aluminum alloy.

Abstract: An aqueous alkaline developing system for alkaline-developable lithographic printing plates and a method for its use are disclosed.

Abstract: A method of processing imageable elements useful as alkaline-developable lithographic printing plate precursors that does not require either a rinsing step or a further gumming step is disclosed.

Abstract: A method for developing exposed lithographic printing plate precursors using a developer and replenisher is disclosed. The replenisher contains a higher concentration of a coating attack-suppressing agent than the developer, so that the aggressiveness of the developer remains substantially constant during the developer loading cycle.

Abstract: A composition for positive correction of lithographic printing plates, applicable by pen or by brush, is disclosed. The correction fluid contains a film forming phosphate ester and a solvent that does not dissolve image areas of the printing plate. A correction kit containing the composition and methods for correcting printing plates by additive correction are also disclosed.

Abstract: Additive compositions suitable for rinse water used for processing lithographic printing plates, particularly to additive compositions for rinse water in water recycling systems, are disclosed. The additive compositions contain at least one water-soluble film-forming polymer; optionally, at least one pH regulating agent capable of maintaining the pH value of an aqueous solution at about 7 or below; and at least one compound selected from the group consisting of phosphonic acid derivatives of formula I.

Abstract: Positive-working imageable elements and methods for their preparation are disclosed. The elements comprise a hydrophilic substrate; a bottom layer, which contains a positive-working photosensitive composition; and a protective overlayer, which has an overlayer material that reduces the solubility of the photosensitive composition in an aqueous alkaline developer. The overlayer may be conveniently applied by a dip and rinse procedure.

Abstract: An aqueous developer for imageable elements that contain a radiation-sensitive initiator system and at least one free radical polymerizable material is disclosed. The developer develops these plates quickly, with high throughput, but with no sludge formation in the developing process. The developer contains water, a buffer, and one or more filter dyes and/or one of more free radical inhibitors. The imageable elements are useful as printing plates.

Abstract: An aqueous developer for imageable elements that contain a radiation-sensitive initiator system and at least one free radical polymerizable material is disclosed. The developer develops these plates quickly, with high throughput, but with no sludge formation in the developing process. The developer contains water, a buffer, and one or more filter dyes and/or one of more free radical inhibitors. The imageable elements are useful as printing plates.