Lithographic printing plate precursor and plate making method of lithographic printing plate

Patent metadata

Field	Value
Publication number	US-9535323-B2
Application number	US-201514667949-A
Country	US
Kind code	B2
Filing date	Mar 25, 2015
Priority date	Sep 26, 2012
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

By a lithographic printing plate precursor including a support having provided thereon an image-recording layer capable of forming an image by supplying at least any of printing ink and dampening water on a printing machine after image exposure to remove an unexposed area thereof, wherein the image-recording layer contains an infrared absorbing agent, a polymerization initiator, a polymerizable compound and a polysaccharide having a sulfonic acid group or a group made by a salt thereof and a plate making method of a lithographic printing plate using the same, a lithographic printing plate precursor which exhibits good development property while maintaining printing durability of a lithographic printing plate after development and a plate making method of a lithographic printing plate using the same can be provided.

First claim

The invention claimed is:

1. A lithographic printing plate precursor comprising a support having provided thereon an image-recording layer capable of forming an image by supplying at least any of printing ink and dampening water on a printing machine after image exposure to remove an unexposed area thereof, wherein the image-recording layer contains an infrared absorbing agent, a polymerization initiator, a polymerizable compound and a polysaccharide having a sulfonic acid group or a group made by a salt thereof,
wherein the polysaccharide is cellulose having a sulfonic acid group or a group made by a salt thereof which has a repeating unit represented by the following formula (1):

wherein R each independently represents a hydrogen atom, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group or -L-SO 3 − X + , n represents an integer of 2 or more, L represents an ethylene group or a propylene group, and X + represents a hydrogen ion, an alkali metal ion or an ammonium ion, provided that of three Rs in the repeating unit represented by formula (1), a number (substitution degree) of R represented by -L-SO 3 − X + is from 0.3 to 2.5.

2. A plate making method of a lithographic printing plate comprising conducting on-press development processing by a method comprising after imagewise exposure of the lithographic printing plate precursor as claimed in claim 1 , mounting the exposed lithographic printing plate precursor on a printing machine and supplying at least any of printing ink and dampening water or a method comprising after mounting the lithographic printing plate precursor as claimed in claim 1 on a printing machine, imagewise exposing the lithographic printing plate precursor and supplying at least any of printing ink and dampening water.

3. The lithographic printing plate precursor as claimed in claim 1 , wherein the image-recording layer contains polymer particles.

4. The lithographic printing plate precursor as claimed in claim 3 , wherein the polymer particles are hydrophobic thermoplastic polymer particles.

5. The lithographic printing plate precursor as claimed in claim 4 , wherein a polymer constituting the hydrophobic thermoplastic polymer particles is a homopolymer or copolymer of a monomer which is selected from the group consisting of ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinyl carbazole, an acrylate or methacrylate having a polyalkylene structure and mixtures thereof.

6. The lithographic printing plate precursor as claimed in claim 5 , wherein the image-recording layer contains an organic borate.

7. The lithographic printing plate precursor as claimed in claim 3 , wherein the polymer particles are microgel particles.

8. The lithographic printing plate precursor as claimed in claim 7 , wherein the image-recording layer contains an organic borate.

9. The lithographic printing plate precursor as claimed in claim 1 , wherein the image-recording layer contains an organic borate.

Assignees

• Fujifilm Corp

Inventors

• Takanashi Genki

Classifications

• B41C2210/04

  Negative working, i.e. the non-exposed (non-imaged) areas are removed · CPC title

• B41C1/10

  for lithographic printing; Master sheets for transferring a lithographic image to the forme {(chemical or electrical pretreatment B41N3/03)}(neutralising or similar differentiation treatments of lithographic printing formes B41N3/08) · CPC title

• B41C1/1008 Primary

  by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials · CPC title

• G03F7/033

  the binders being polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers · CPC title

• B41C2210/08

  Developable by water or the fountain solution · CPC title