LITHOGRAPHIC PRINTING PLATE PRECURSOR, METHOD OF PRODUCING LITHOGRAPHIC PRINTING PLATE, AND LITHOGRAPHIC PRINTING METHOD
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.
1 . A lithographic printing plate precursor comprising an image recording layer containing an infrared absorber represented by Formula I, on a support:
in Formula I, each of X 1 and X 2 independently represents a sulfur atom, an oxygen atom, or a dialkylmethylene group having 12 or less carbon atoms, each of Y 1 and Y 2 independently represents a monovalent organic group or a hydrogen atom, each of Z 1 and Z 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 1 , R 2 , R 3 , and R 4 independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms, each of R 5 and R 6 independently represents a hydrocarbon group which optionally forms a 5-membered ring or a 6-membered ring, each of R 7 , R 8 , R 9 , and R 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:
in Formula II, each of X 1 and X 2 independently represents a sulfur atom, an oxygen atom, or a dialkylmethylene group having 12 or less carbon atoms, each of Y 1 and Y 2 independently represents a monovalent organic group or a hydrogen atom, each of Z 1 and Z 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 1 , R 2 , R 3 , and R 4 independently represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms, each of R 7 , R 8 , R 9 , and R 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 μm to 50 μm.
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.