Planographic printing plate material and its manufacturing process

Abstract

Disclosed is a planographic printing plate material comprising a hydrophilic support and provided thereon, an image formation layer whose alkali solubility is changed after near-infrared laser exposure, wherein the image formation layer contains, as a infrared absorbent, a compound having absorption maximum in the wavelength regions of from 700 to 900 nm, the compound being selected from the group consisting of compounds represented by formulae IRD1, IRD2 and IRD3,

Description

Claims

1. A planographic printing plate material comprising a hydrophilic support and provided thereon, an image formation layer whose alkali solubility is changed after near-infrared laser exposure, wherein the image formation layer contains, as an infrared absorbent, a compound having absorption maximum in the wavelength regions of from 700 to 900 nm, the compound being selected from the group consisting of compounds represented by formulae IRD1, IRD2 and IRD3,

2. The planographic printing plate material of claim 1, wherein the compound represented by formula IRD2 and the compound represented by formula IRD3 is a compound represented by formula IRD4, and a compound represented by formula IRD5, respectively,

3. The planographic printing plate material of claim 2, wherein the compound represented by formula IRD4 and the compound represented by formula IRD5 is a compound represented by formula IRD6, and a compound represented by formula IRD7, respectively,

4. The planographic printing plate material of claim 3, wherein the compound represented by formula IRD6 and the compound represented by formula IRD7 is a compound represented by formula IRD8, and a compound represented by formula IRD9, respectively,

5. The planographic printing plate material of claim 4, wherein the compound represented by formula IRD8 is a compound represented by formula IRD10,

6. The planographic printing plate material of claim 1, wherein the hydrophilic support is an aluminum support obtained by a process comprising the steps of electrolytically surface roughening an aluminum plate and anodizing the electrolytically surface roughened aluminum plate, and the image formation layer further contains an alkali soluble binder, a cross-linking agent and an acid generation compound.

7. The planographic printing plate material of claim 6, wherein the alkali soluable binder is novolak resin.

8. The planographic printing plate material of claim 6, wherein the cross-linking agent is a melamine resin.

9. The planographic printing plate material of claim 6, wherein the acid generation compound is a triazine compound.

10. The planographic printing plate material of claim 6, wherein the electrolytically surface roughening is carried out in a hydrochloric acid solution.

11. The planographic printing plate material of claim 1, the hydrophilic support is an aluminum support obtained by a process comprising the steps of electrolytically surface roughening an aluminum plate and anodizing the electrolytically surface roughened aluminum plate, and the image formation layer further contains an alkali soluble binder, an acid decomposable compound and an acid generation compound.

12. The planographic printing plate material of claim 11, wherein the alkali soluble binder is novolak resin.

13. The planographic printing plate material of claim 11, wherein the acid generation compound is a triazine compound.

14. The planographic printing plate material of claim 11, wherein the electrolytically surface roughening is carried out in a hydrochloric acid solution.

15. A process of manufacturing a planographic printing plate material, the process comprising the steps of: dissolving a composition comprising a compound having absorption maximum in the wavelength regions of from 700 to 900 nm in a ketone solvent to provide a light sensitive coating liquid; andcoating the light sensitive coating liquid on a hydrophilic support, wherein the compound is selected from the group consisting of compounds represented by formulae IRD1, IRD2 and IRD3,