US 6,632,589 B2Granted

Lithographic printing process

AssigneeFuji Photo Film Co., Ltd.

InventorsToshifumi Inno, Hiromichi Tachikawa, Keiji Akiyama

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Abstract

A hydrophilic layer and an overcoat layer are provided in this order on a heat-sensitive layer having an ink receiving surface, so as to form an original (plate) for a lithographic printing plate. The overcoat layer can be removed during printing. A system capable of forming an inorganic hydrophilic matrix by sol-gel conversion is provided in the hydrophilic layer. Adhesion between the heat-sensitive layer and the hydrophilic layer decreases in a heated region through image processing. Emulsion ink is supplied to the plate surface during printing, whereby the overcoat layer and the hydrophilic layer at an image portion are removed with a hydrophilic component of the emulsion ink. Thus, with a heat-sensitive original that can be subjected to heat-mode prepress using laser exposure, good printed matter can be stably obtained, irrespective of balance between image and non-image portions, without using wetting water.

Claims10

Dependent claims

A lithographic printing process comprising:

(a) a step of providing an overcoat layer, which can be removed during printing, on a heat-sensitive lithographic printing plate original which includes a step of sequentially providing a hydrophilic layer and said overcoat layer on a heat-sensitive layer having an ink receiving surface;
(b) a step of conducting image recording on said lithographic printing plate original provided with said overcoat layer which includes a step of subjecting to thermal action a surface of said heat-sensitive layer at a heating region, and, subsequent to said step of subjecting to thermal action, a step of decreasing adhesion between said heat-sensitive layer and said hydrophilic layer for forming an image portion at which said hydrophilic layer is removable;
and
(c) a step of printing, after said image recording, using emulsion ink that has been obtained by adding and emulsifying a hydrophilic component, which contains at least one of water and a polyhydric alcohol as a main component, into an oleophilic ink component, said step including a step of removing said overcoat layer and said heated region of said hydrophilic layer by supplying said emulsion ink to a plate surface during printing.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 09/835,563Filed 17 Apr 2001
Priority: JP 2000-12072421 Apr 2000
Published: US 2002/0012881 A131 Jan 2002
Granted: 14 Oct 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

C09B 23/0066
Methine or polymethine dyes, e.g. cyanine dyes: the polymethine chain being part of a carbocyclic ring,
B41C 1/1008
For lithographic printing; Master sheets for transferring a lithographic image to the forme: by removal or destruction of lithographic material on…
C09B 23/0008
Methine or polymethine dyes, e.g. cyanine dyes: substituted on the polymethine chain
C09B 23/0016
Substituted on the polymethine chain: the substituent being a halogen atom