# US 7,745,090 B2 · Production method of lithographic printing plate, lithographic printing plate precursor and lithographic printing method

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- Number: US 7,745,090 B2
- Document ID: US7745090B2
- Status: Granted
- Kind: B2
- Application number: 11/209,798
- Filed: 2005-08-24
- Published: 2006-03-02
- Granted: 2010-06-29
- Earliest claimed: 2004-08-24
- Assignees: FUJIFILM Corporation
- Inventors: Tomoyoshi Mitsumoto; Toshifumi Inno
- Web page: https://patentgrep.com/patent/US7745090B2

## CPC

- B41C 1/1016: {characterised by structural details, e.g. protective layers, backcoat layers or several imaging layers}
- G03F 7/3035: {from printing plates fixed on a cylinder or on a curved surface; from printing cylinders}
- G03F 7/305: {characterised by the brushing or rubbing means}
- B41C 2201/02: Cover layers; Protective layers
- B41C 2201/04: Intermediate layers
- B41C 2201/06: Backcoats; Back layers
- B41C 2201/10: characterised by inorganic compounds, e.g. pigments
- B41C 2201/14: characterised by macromolecular organic compounds, e.g. binder, adhesives
- B41C 2210/04: Negative working, i.e. the non-exposed (non-imaged) areas are removed
- B41C 2210/06: Developable by an alkaline solution
- B41C 2210/10: Developable by an acidic solution
- B41C 2210/20: characterised by inorganic additives, e.g. pigments, salts
- B41C 2210/22: characterised by organic non-macromolecular additives, e.g. dyes, UV-absorbers, plasticisers
- B41C 2210/24: characterised by a macromolecular compound or binder obtained by reactions involving carbon-to-carbon unsaturated bonds, e.g. acrylics, vinyl polymers
- B41C: PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES (photomechanical processes for producing printing surfaces G03F; photoelectrical processes for producing printing surfaces G03G)
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)

## Abstract

A method for producing a lithographic printing plate is provided, wherein, in the non-alkaline development of a lithographic printing plate precursor having a protective layer, even if the protective layer components are mingled into the developer, the reduction in development removability of the image recording layer and the generation of development scum can be inhibited; an on-press development type lithographic printing plate precursor with excellent inking property, high scratch resistance, satisfied on-press developability and good fine line reproducibility is provided; and a lithographic printing method is provided, each of which is a method for producing a lithographic printing plate, comprising: imagewise exposing a lithographic printing plate precursor comprising a support, an image recording layer and a protective layer, and rubbing the plate surface by a rubbing member of an automatic processor in the presence of a developer at a pH of 2 to 10 to remove the protective layer and the image recording layer in the unexposed area; a lithographic printing plate precursor comprising a support, an image recording layer removable with a printing ink and/or a fountain solution, and a protective layer containing a polyvinyl alcohol having a carboxyl group and/or a sulfonic acid group within the molecule; and a lithographic printing method comprising on-press development.

## Claims

### Claim 1

A lithographic printing plate precursor comprising a support, a radical polymerizable image recording layer and a protective layer in this order, wherein the radical polymerizable image recording layer is removable with a printing ink and/or a fountain solution, and the protective layer contains (1) a polyvinyl alcohol having a sulfonic acid group within the molecule, and (2) an inorganic layered compound, wherein said inorganic layered compound is a mica, and wherein said radical polymerizable image recording layer comprises a binder polymer containing a monomer unit represented by either one of the following formulae:

### Claim 2 (depends on 1)

The lithographic printing plate precursor as claimed in claim 1, wherein the acid modification ratio of said polyvinyl alcohol is from 3 to 8%.

### Claim 3 (depends on 1)

The lithographic printing plate precursor as claimed in claim 1, wherein the radical polymerizable image recording layer comprises a microcapsule or a microgel.

### Claim 4 (depends on 1)

A lithographic printing method comprising:
imagewise exposing the lithographic printing plate precursor claimed in claim 1 by the irradiation of an infrared ray at a wavelength of 760 to 1,200 nm;
supplying a printing ink and a fountain solution to remove said radical polymerizable image recording layer in the portion unirradiated with the infrared ray; and
performing printing.

### Claim 5 (depends on 1)

A lithographic printing method comprising: imagewise exposing the lithographic printing plate precursor claimed in claim 1 by the irradiation of an ultraviolet ray at a wavelength of 250 to 420 nm; supplying a printing ink and a fountain solution to remove said radical polymerizable image recording layer in the portion unirradiated with the ultraviolet ray; and performing printing.

### Claim 6 (depends on 1)

The lithographic printing plate precursor as claimed in claim 1, wherein the radical polymerizable image recording layer contains (1) a polymerization initiator, (2) a polymerizable compound and (3) said binder polymer.

### Claim 7 (depends on 1)

The lithographic printing plate precursor as claimed in claim 1, wherein said binder polymer has an ethylenically unsaturated bond in a side chain.