LITHOGRAPHIC PRINTING PLATE PRECURSOR, METHOD OF PRODUCING LITHOGRAPHIC PRINTING PLATE, AND LITHOGRAPHIC PRINTING METHOD

Abstract

A lithographic printing plate precursor including an image recording layer containing an infrared absorber represented by Formula I, on a support, and a method of producing a lithographic printing plate and a lithographic printing method using the lithographic printing plate precursor.

##STR00001##

Claims

1. A lithographic printing plate precursor comprising an image recording layer containing an infrared absorber represented by Formula I, on a support: ##STR00019## in Formula I, each of X.sup.1 and X.sup.2 independently represents a sulfur atom, an oxygen atom, or a dialkylmethylene group having 12 or less carbon atoms, each of Y.sup.1 and Y.sup.2 independently represents a monovalent organic group or a hydrogen atom, each of Z.sup.1 and Z.sup.2 independently represents a benzene ring, a naphthalene ring, or a 6- to 20-membered heteroaromatic ring unsubstituted or substituted with an electron-donating group or an aryl group having from 6 to 20 carbon atoms, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms, each of R.sup.5 and R.sup.6 independently represents a hydrocarbon group which optionally forms a 5-membered ring or a 6-membered ring, each of R.sup.7, R.sup.8, R.sup.9, and R.sup.10 independently represents a hydrogen atom or a monovalent organic group, and A represents a counter ion present in a case in which charge neutralization is needed.

2. The lithographic printing plate precursor according to claim 1, wherein the infrared absorber represented by Formula I is an infrared absorber represented by Formula II: ##STR00020## in Formula II, each of X.sup.1 and X.sup.2 independently represents a sulfur atom, an oxygen atom, or a dialkylmethylene group having 12 or less carbon atoms, each of Y.sup.1 and Y.sup.2 independently represents a monovalent organic group or a hydrogen atom, each of Z.sup.1 and Z.sup.2 independently represents a benzene ring, a naphthalene ring, or a 6- to 20-membered heteroaromatic ring unsubstituted or substituted with an electron-donating group or an aryl group having from 6 to 20 carbon atoms, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms, each of R.sup.7, R.sup.8, R.sup.9, and R.sup.10 independently represents a hydrogen atom or a monovalent organic group, and A represents a counter ion present in a case in which charge neutralization is needed.

3. The lithographic printing plate precursor according to claim 1, wherein the image recording layer further contains a polymerizable compound and a polymerization initiator.

4. The lithographic printing plate precursor according to claim 3, wherein the polymerization initiator is an iodonium-based polymerization initiator.

5. The lithographic printing plate precursor according to claim 2, wherein the image recording layer further contains a polymerizable compound and a polymerization initiator.

6. The lithographic printing plate precursor according to claim 5, wherein the polymerization initiator is an iodonium-based polymerization initiator.

7. The lithographic printing plate precursor according to claim 1, wherein the image recording layer further contains a thermoplastic polymer particle.

8. The lithographic printing plate precursor according to claim 7, wherein the polymer contained in the thermoplastic polymer particle contains any or both monomer units of a monomer unit derived from styrene and a monomer unit derived from an acrylic compound.

9. The lithographic printing plate precursor according to claim 7, wherein the polymer contained in the thermoplastic polymer particle is a styrene-acrylonitrile resin.

10. The lithographic printing plate precursor according to claim 7, wherein the weight average molecular weight of the polymer contained in the thermoplastic polymer particle is from 5,000 to 1,000,000.

11. The lithographic printing plate precursor according to claim 7, wherein the volume average particle size of the thermoplastic polymer particle is from 0.01 m to 50 m.

12. The lithographic printing plate precursor according to claim 7, wherein the content of the thermoplastic polymer particle with respect to the total mass of the image recording layer is from 20% by mass to 95% by mass.

13. The lithographic printing plate precursor according to claim 2, wherein the image recording layer further contains a thermoplastic polymer particle.

14. The lithographic printing plate precursor according to claim 13, wherein the polymer contained in the thermoplastic polymer particle contains any or both monomer units of a monomer unit derived from styrene and a monomer unit derived from an acrylic compound.

15. The lithographic printing plate precursor according to claim 13, wherein the polymer contained in the thermoplastic polymer particle is a styrene-acrylonitrile resin.

16. The lithographic printing plate precursor according to claim 1, wherein the image recording layer further contains a leuco compound.

17. The lithographic printing plate precursor according to claim 1, wherein the image recording layer is removable by any or both of dampening water and a printing ink.

18. The lithographic printing plate precursor according to claim 1, wherein the image recording layer is gum-developable.

19. A method of producing a lithographic printing plate, comprising: an exposure step of image-wise exposing the lithographic printing plate precursor according to claim 1, to form an exposed area and an unexposed area; and an on-press development step of feeding at least one of a printing ink or dampening water to remove the unexposed area.

20. A lithographic printing method comprising: an exposure step of image-wise exposing the lithographic printing plate precursor according to claim 1, to form an exposed area and an unexposed area; an on-press development step of feeding at least one of a printing ink or dampening water to remove the unexposed area; and a printing step of feeding a printing ink to a lithographic printing plate subjected to on-press development in the on-press development step, to perform printing on a recording medium, in this order.

Description

BRIEF DESCRIPTION OF DRAWING

[0313] FIG. FIG. 1 is a schematic view illustrating one structure example of a development treatment apparatus used in the invention.

REFERENCE SINGS LIST

[0314] 11: rolling brush roll

[0315] 12: backing roll

[0316] 13: conveyance roll

[0317] 14: conveyance guide plate

[0318] 15: spray pipe

[0319] 16: pipe line

[0320] 17: filter

[0321] 18: plate charge stand

[0322] 19: plate discharge stand

[0323] 20: treatment liquid tank

[0324] 21: circulation pump

[0325] 22: drier

[0326] 30: lithographic printing plate precursor