Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/06—Lithographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/12—Printing plates or foils; Materials therefor non-metallic other than stone, e.g. printing plates or foils comprising inorganic materials in an organic matrix
  • B41N1/14—Lithographic printing foils
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • 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
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • 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
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • 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
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
  • G03F7/028—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with photosensitivity-increasing substances, e.g. photoinitiators
  • G03F7/029—Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur

Definitions

• This disclosure relates to an on-press development type lithographic printing plate precursor, a method for making a lithographic printing plate, a lithographic printing method, and a compound.
• a lithographic printing plate is composed of an oleophilic image area that accepts ink during the printing process and a hydrophilic non-image area that accepts dampening water.
• Lithographic printing utilizes the mutual repulsion properties of water and oil-based ink, making the oleophilic image area of the lithographic printing plate the ink-receptive area and the hydrophilic non-image area the dampening water-receptive area (ink non-receptive area) to create a difference in ink adhesion on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing material such as paper to print.
• a lithographic printing plate precursor PS plate having an oleophilic photosensitive resin layer (image recording layer) provided on a hydrophilic support
• PS plate lithographic printing plate precursor
• image recording layer oleophilic photosensitive resin layer
• hydrophilic support exposing the hydrophilic support surface to form a non-image area, thereby obtaining a lithographic printing plate.
• JP2020-069789A discloses a lithographic printing plate precursor having an image recording layer on a support, the image recording layer including an infrared absorbing agent that decomposes upon exposure to infrared light, a binder polymer having a structural unit formed from an aromatic vinyl compound, a polymerization initiator, and a polymerizable compound.
• JP2011-186367A describes a lithographic printing plate precursor that includes a photosensitive composition that contains (A) an organic boron salt represented by the following general formula I, (B) a trihaloalkyl-substituted compound, (C) a cyanine dye that has absorption in the wavelength range of 400 nm to 900 nm, and (D) a compound that has a polymerizable double bond group.
• A an organic boron salt represented by the following general formula I
• B a trihaloalkyl-substituted compound
• C a cyanine dye that has absorption in the wavelength range of 400 nm to 900 nm
• D a compound that has a polymerizable double bond group.
• R 1 , R 2 , R 3 and R 4 each represent an aryl group represented by the following general formula II, and A + represents a group capable of forming a cation.
• R 5 , R 6 , R 7 , R 8 and R 9 each independently represent a hydrogen atom or a group selected from an alkyl group, an alkylene group, an alkoxy group and an aryl group having 1 to 10 carbon atoms, some of which may be bonded to form a ring.
• An on-press development type lithographic printing plate precursor wherein an image recording layer comprises the following (1) or (2): (1) A borate compound represented by the following formula (1) and an electron-accepting polymerization initiator
• R 1 , R 2 , R 3 and R 4 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted alkynyl group, and R 1 , R 2 , R 3 and R 4 each independently may have a ring structure. However, at least one of R 1 , R 2 , R 3 and R 4 is different from the others.
• M + represents a cation.
• R 1 , R 2 , R 3 and R 4 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted alkynyl group, and R 1 , R 2 , R 3 and R 4 each independently may have a ring structure. However, at least one of R 1 , R 2 , R 3 and R 4 is different from the others.
• Ma + represents an iodonium cation.
• ⁇ 2> The on-press development type lithographic printing plate precursor according to ⁇ 1>, in which R 1 , R 2 and R 3 in formula (1) or formula (1a) are phenyl groups, and R 4 is different from R 1 , R 2 and R 3 .
• ⁇ 3> The on-press development type lithographic printing plate precursor according to ⁇ 1> or ⁇ 2>, in which R 1 , R 2 and R 3 in formula (1) or formula (1a) are phenyl groups, and R 4 is an aryl group having a substituent.
• ⁇ 4> The on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 3>, wherein M 1 + in formula (1) is an inorganic cation.
• ⁇ 5> The on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 3>, wherein M + in formula (1) is at least one cation selected from the group consisting of iodonium cations and infrared absorbing dye cations.
• M + in formula (1) is at least one cation selected from the group consisting of iodonium cations and infrared absorbing dye cations.
• R 1 , R 2 , and R 3 in formula (1) or formula (1a) are phenyl groups
• R 4 is an aryl group having a substituent
• the total number of carbon atoms and oxygen atoms of the substituent is 2 or more.
• ⁇ 7> The on-press development type lithographic printing plate precursor according to ⁇ 6>, wherein the total number of carbon atoms and oxygen atoms in the substituent is 3 or more.
• ⁇ 8> The on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 7>, wherein in formula ( 1 ) or formula (1a ) , R 1 , R 2 and R 3 are phenyl groups substituted with an electron-withdrawing group, and R 4 is a group different from R 1 , R 2 and R 3 .
• ⁇ 9> The on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 8>, wherein the substituent of R4 in formula (1) or formula (1a) is at least one group selected from the group consisting of an alkyl group, an aryl group, an alkenyl group, an alkoxy group, an ester group, a carbonyl group, and an amide group.
• the image recording layer contains a color former.
• ⁇ 11> The on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 10>, wherein the image recording layer contains an infrared absorbing agent.
• R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkoxy group having 2 to 9 carbon atoms, at least one of R 3 and R 4 is different from R 1 or R 2 , the difference between the total number of carbon atoms in R 1 and R 2 and the total number of carbon atoms in R 3 and R 4 is 0 to 4, the difference between the total number of carbon atoms in R 1 and R 2 and the total number of carbon atoms in R 5 and R 6 is 0 to 4, and X 1 , X 2 and X 3 are each independently a counter anion.
• Ar 11 and Ar 12 each independently represent a substituted or unsubstituted aromatic ring or an atomic group necessary for forming a substituted or unsubstituted heteroaromatic ring;
• R 11 and R 12 each independently represent a substituted or unsubstituted alkyl group;
• R 13 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;
• R 14 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;
• Y each independently represents an oxygen atom, a sulfur atom, or a dialkylmethylene group represented by >C(R 15 R 16 );
• R 15 and R 16 each independently represent a substituted or unsubstituted alkyl group having 1
• R 1 and R 2 each independently represent a hydrogen atom or an alkyl group
• R 1 and R 2 may be bonded to each other to form a ring
• R 3 to R 6 each independently represent a hydrogen atom or an alkyl group
• R 7 and R 8 each independently represent an alkyl group or an aryl group
• Y 1 and Y 2 each independently represent an oxygen atom, a sulfur atom, -NR 0 - or a dialkylmethylene group
• R 0 represents a hydrogen atom, an alkyl group or an aryl group
• Ar 1 and Ar 2 each independently represent a group forming a benzene ring or naphthalene ring which may have a group represented by formula 2 described later
• a 1 represents -NR 9 R 10 , -X 1 -L 1 or a group represented by formula 2 described later
• R 9 and R 10 each independently represent an alkyl group, an aryl group, an alkoxycarbonyl group or an aryls
• R P1 represents a group represented by formula (P2) or formula (P3) below
• R P2 and R P3 each independently represent a hydrogen atom or an alkyl group
• R P2 and R P3 may be bonded to each other to form a ring
• Ar P1 and Ar P2 each independently represent a benzene ring or a naphthalene ring
• Y P1 and Y P2 each independently represent an oxygen atom, a sulfur atom, -NR P0 - or a dialkylmethylene group
• R P4 and R P5 each independently represent an alkyl group
• R P6 to R P9 each independently represent a hydrogen atom or an alkyl group
• R P0 represents a hydrogen atom, an alkyl group, or an aryl group
• Za represents a counter ion that neutralizes the charge.
• R P10 represents a monovalent organic group having an aryl group
• R P11 to R P14 and R P17 to R P20 each independently represent a hydrogen atom, an alkyl group, an aryl group, a hydroxyl group, an alkoxy group, or a halogen atom
• R P15 and R P16 each independently represent a hydrogen atom, an alkyl group, or an aryl group
• at least two of R P11 to R P20 may be bonded to form a ring structure
• * represents a single bond bonded to the oxygen atom in formula (P1).
• R and R each independently represent a hydrogen atom or an alkyl group
• R represents a hydrogen atom or a monovalent substituent
• L and L each independently represent a single bond or a divalent linking group
• Rh represents a substituent containing two or more silicon atoms.
• ⁇ 17> A process for imagewise exposing the on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 16>; and removing the image recording layer in the non-image area by supplying at least one selected from the group consisting of printing ink and dampening water on the printing press.
• ⁇ 18> A step of imagewise exposing an on-press development type lithographic printing plate precursor according to any one of ⁇ 1> to ⁇ 16>; a step of removing the image recording layer in the non-image area by supplying at least one selected from the group consisting of a printing ink and a dampening water on a printing press to prepare a lithographic printing plate; and printing with the obtained lithographic printing plate.
• R represents a group in which the total number of carbon atoms and oxygen atoms is 2 or more, X represents a halogen atom, an alkyl group, or an alkoxy group, and the sum of the Hammett values of R and X is ⁇ 0.09 to 0.09.
• M + represents Li + , Na + , K + , an iodonium cation, or an infrared absorbing dye cation.
• R represents an alkyl group having 2 or more carbon atoms, or an alkoxy group in which the sum of the number of carbon atoms and oxygen atoms is 2 or more.
• M + represents an iodonium cation or an infrared absorbing dye cation.
• R in formula (II) is an alkyl group having 2 or more and 4 or less carbon atoms in total, or an alkoxy group having 2 or more and 4 or less carbon atoms and oxygen atoms in total.
• R in formula (II) is an alkyl group having 2 or more and 4 or less carbon atoms in total, or an alkoxy group having 2 or more and 4 or less carbon atoms and oxygen atoms in total.
• an on-press development type lithographic printing plate precursor that is excellent in printing durability and suppression of development defects over time.
• a method for producing a lithographic printing plate using the on-press development type lithographic printing plate precursor or a lithographic printing method can be provided.
• a novel borate compound can be provided.
• FIG. 2 is a schematic cross-sectional view of one embodiment of a support.
• FIG. 2 is a schematic cross-sectional view of another embodiment of a support.
• FIG. 2 is a schematic view of an anodizing apparatus used in an anodizing treatment in the method for producing a support having an anodized coating.
• This is a 1 H-NMR chart of compound B-5.
• This is a 1 H-NMR chart of compound B-7.
• an "alkyl group” includes not only an alkyl group that has no substituents (unsubstituted alkyl groups) but also an alkyl group that has a substituent (substituted alkyl groups).
• (meth)acrylic is a term used as a concept that includes both acrylic and methacrylic
• (meth)acryloyl is a term used as a concept that includes both acryloyl and methacryloyl.
• step in the present disclosure includes not only an independent step, but also a step that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved.
• each component in a composition or each structural unit in a polymer in the present disclosure may be contained alone or in combination of two or more types.
• the amount of each component in a composition or each structural unit in a polymer means, when a plurality of substances or structural units corresponding to each component or each structural unit in a polymer are present in the composition, the total amount of the corresponding plurality of substances present in the composition or the corresponding plurality of structural units present in the polymer, unless otherwise specified.
• combinations of two or more preferred aspects are more preferred aspects.
• the weight average molecular weight (Mw) and number average molecular weight (Mn) are molecular weights detected by a gel permeation chromatography (GPC) analyzer using columns of TSKgel GMHxL, TSKgel G4000HxL, or TSKgel G2000HxL (all product names manufactured by Tosoh Corporation) in a differential refractometer using THF (tetrahydrofuran) as a solvent, and converted using polystyrene as a standard substance.
• GPC gel permeation chromatography
• the term "lithographic printing plate precursor” includes not only lithographic printing plate precursors but also throwaway plate precursors.
• lithographic printing plate includes not only lithographic printing plates prepared by subjecting a lithographic printing plate precursor to operations such as exposure and development as necessary, but also throwaway plates. In the case of a throwaway plate precursor, the operations of exposure and development are not necessarily required. Note that a throwaway plate is a lithographic printing plate precursor that is attached to an unused plate cylinder when, for example, a portion of the page is printed in one color or two colors in color newspaper printing. In the present disclosure, "*" in a chemical structural formula represents a bonding position to another structure.
• the on-press development type lithographic printing plate precursor (also simply referred to as “lithographic printing plate precursor”) according to the present disclosure has a support and an image recording layer on the support, and the image recording layer has the following properties (1 ), or the following (2).
• a borate compound represented by formula (1) and an electron-accepting polymerization initiator (2) a borate compound represented by formula (1a)
• the photosensitive layer is a negative-working lithographic printing plate precursor that undergoes polymerization.
• the present inventors have found that it is difficult to obtain a lithographic printing plate precursor having excellent printing durability and suppression of development defects over time using conventional lithographic printing plate precursors such as those described in JP2020-069789A or JP2011-186367A. Therefore, the present inventors conducted extensive research and found that, by having an image recording layer with the above-mentioned composition, a lithographic printing plate precursor excellent in printing durability and suppression of development defects over time can be obtained. Although the detailed mechanism by which the above effects are obtained is unclear, it is speculated as follows. The degree of hardening of the exposed area (image area) is considered to be one of the factors that causes the deterioration of printing durability.
• the degree of hardening of the exposed area is affected by the amount of radicals generated by the reaction of a polymerization initiator such as a borate compound contained in the image recording layer. Since the reaction of the polymerization initiator depends on the potential of the polymerization initiator, the amount of radicals generated can be adjusted by controlling the potential.
• the borate compound having an asymmetric structure represented by formula (1) or formula (1a) allows precise potential control compared to a borate compound having a symmetric structure, and the amount of radicals generated can be adjusted. As a result, it is presumed that the printing durability is improved.
• the image recording layer includes the above-mentioned aspects (1) and (2).
• the above embodiment (1) of the image recording layer will also be referred to as “embodiment A.”
• the above embodiment (2) of the image recording layer will also be referred to as “embodiment B.”
• the borate compound represented by formula (1) and the borate compound represented by formula (1a) are also collectively referred to as "specific borate compound”.
• the image recording layer in the lithographic printing plate precursor according to the present disclosure is preferably a water-soluble or water-dispersible negative-type image recording layer. From the viewpoint of on-press developability, the image recording layer in the lithographic printing plate precursor according to the present disclosure is preferably such that the unexposed areas of the image recording layer are removable with at least one of fountain solution and printing ink.
• the image recording layer in embodiment A contains a borate compound represented by the following formula (1).
• the borate compound represented by formula (1) is used as an electron-donating polymerization initiator in the image recording layer.
• the specific borate compound is a compound that generates polymerization initiating species such as radicals or cations by the energy of light, heat or both.
• R 1 , R 2 , R 3 , and R 4 each independently represent an unsubstituted or substituted alkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted alkenyl group, or an unsubstituted or substituted alkynyl group, and R 1 , R 2 , R 3 , and R 4 each independently may have a ring structure. However, at least one of R 1 , R 2 , R 3 , and R 4 is different from the others.
• M + represents a cation.
• Examples of the alkyl group represented by R 1 , R 2 , R 3 , or R 4 include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, t-butyl, isopentyl, neopentyl, 1-methylbutyl, isohexyl, 2-ethylhexyl, 2-methylhexyl, cyclohexyl, cyclopentyl, and 2-norbornyl groups.
• the alkyl group may be linear, branched, or have a ring structure.
• the alkyl group represented by R 1 , R 2 , R 3 , or R 4 may have a substituent.
• substituent of the alkyl group include a halogen atom, an alkyl group, an aryl group, an alkenyl group, an alkoxy group, an ester group, a carbonyl group, a sulfonyl group, an amino group, an amide group, and combinations thereof.
• the alkyl group represented by R 1 , R 2 , R 3 , or R 4 is preferably an unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, more preferably an unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, and even more preferably an unsubstituted linear or branched alkyl group having 1 to 6 carbon atoms.
• a branched unsubstituted alkyl group is particularly preferable.
• the aryl group represented by R 1 , R 2 , R 3 , or R 4 includes an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, and a fluorenyl group.
• Examples of the substituent on the aryl group include the above-mentioned alkyl group substituents.
• the aryl group represented by R 1 , R 2 , R 3 or R 4 is preferably each independently an unsubstituted or substituted phenyl group.
• the alkenyl group represented by R 1 , R 2 , R 3 or R 4 includes an alkenyl group having 2 to 20 carbon atoms, such as a vinyl group, a 1-propenyl group, a 1-butenyl group, a cinnamyl group, and a 2-chloro-1-ethenyl group.
• the alkenyl group represented by R 1 , R 2 , R 3 or R 4 may be linear, branched or have a ring structure. Examples of the substituent for the alkenyl group include the above-mentioned alkyl group substituents.
• the alkenyl group represented by R 1 , R 2 , R 3 or R 4 is preferably each independently an unsubstituted alkenyl group having 2 to 20 carbon atoms.
• the alkynyl group represented by R 1 , R 2 , R 3 or R 4 includes an alkynyl group having 2 to 20 carbon atoms, such as an ethynyl group, a 1-propynyl group, a 1-butynyl group, a trimethylsilylethynyl group, and a phenylethynyl group.
• the alkynyl group may be linear or branched.
• R 1 , R 2 , R 3 , and R 4 are each independently a substituted or unsubstituted aryl group.
• R 1 , R 2 , R 3 , and R 4 are each independently a substituted or unsubstituted aryl group, the HOMO potential of the borate compound is lowered, and the film stability of the image recording layer is improved, thereby extending the life of the lithographic printing plate.
• R 1 , R 2 , R 3 and R 4 are different from the others.
• R 1 , R 2 and R 3 are the same among R 1 , R 2 , R 3 and R 4 , and R 4 is different from R 1 , R 2 and R 3.
• R 1 , R 2 and R 3 are phenyl groups.
• R 1 , R 2 , R 3 and R 4 are phenyl groups and at least one is a substituted aryl group. It is more preferable that R 1 , R 2 and R 3 are phenyl groups, and R 4 is an aryl group having a substituent (i.e., a substituted aryl group).
• R 1 , R 2 , and R 3 are phenyl groups and R 4 is an aryl group having a substituent
• the total number of carbon atoms and oxygen atoms in the substituent of the aryl group is preferably 2 or more, and more preferably 3 or more.
• the upper limit is, for example, 8 or less.
• the compound represented by formula (1) is preferably a compound represented by the following formula (II):
• R represents an alkyl group having 2 or more carbon atoms, or an alkoxy group in which the sum of the number of carbon atoms and oxygen atoms is 2 or more.
• M + represents an iodonium cation or an infrared absorbing dye cation.
• the alkyl group represented by R preferably has 2 to 8 carbon atoms, more preferably has 2 to 6 carbon atoms, and further preferably has 2 to 4 carbon atoms.
• the alkyl group include an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, an isobutyl group, a sec-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a neopentyl group, and an isopropyl group.
• the alkyl group may be linear, branched, or have a ring structure.
• the alkoxy group for R preferably has 2 to 4 carbon atoms and oxygen atoms in total.
• Examples of the alkoxy group include a methoxy group, a n-propoxy group, an isopropoxy group, and a n-butoxy group.
• the alkoxy group may be linear or branched.
• the phenyl group represented by R 1 , R 2 or R 3 is preferably a phenyl group substituted with an electron-withdrawing group.
• the electron-withdrawing group include a halogen atom and a fluoroalkyl group, of which a fluorine atom, a chlorine atom, and a fluoroalkyl group having 1 to 3 carbon atoms are preferred.
• the substituent of the aryl group represented by R4 is preferably an alkyl group, an aryl group, an alkenyl group, an alkoxy group, an ester group, a carbonyl group, or an amide group, more preferably an alkyl group, an alkenyl group, or an alkoxy group, and further preferably an alkyl group or an alkoxy group.
• the compound represented by the above formula (1) may be a compound represented by the following formula (I):
• R represents a group in which the total number of carbon atoms and oxygen atoms is 2 or more, X represents a halogen atom, an alkyl group, or an alkoxy group, and the sum of the Hammett values of R and X is ⁇ 0.09 to 0.09.
• M + represents Li + , Na + , K + , an iodonium cation, or an infrared absorbing dye cation.
• R in formula (I) can be, for example, an alkyl group, an aryl group, an alkenyl group, an alkoxy group, an ester group, a carbonyl group, a sulfonyl group, an amide group, or a combination thereof.
• examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, and a bromine atom.
• the alkyl group and alkoxy group represented by X are the same as the alkyl group and alkoxy group in formula (II) above, and preferred embodiments are also the same.
• R in formula (I) is preferably an alkyl group having 2 to 4 carbon atoms, or an alkoxy group having 2 to 4 carbon atoms in total, and more preferably an alkyl group having 2 to 4 carbon atoms.
• X is preferably a halogen atom.
• the halogen atoms may each independently be different halogen atoms, but it is more preferable that they are all the same halogen atom.
• the sum of the Hammett ⁇ values of the substituents (R and X) introduced into the aryl skeleton is preferably within the range of ⁇ 0.2 to 0.2, and more preferably within the range of ⁇ 0.09 to 0.09. By being within this range, the HOMO potential can be adjusted to a desired range, and the film stability and printing durability of the image recording layer are well balanced.
• the total Hammett ⁇ value of the substituents introduced into the aryl skeleton was calculated using the values described in the reference "Chemical Seminar 10: Hammett Side - Structure and Reactivity" (by Naoki Inamoto, Maruzen Co., Ltd., published in June 1983).
• M + in formula (1) represents a cation. That is, M + is a counter cation of a boron anion.
• M + is not particularly limited as long as it is a cation that can neutralize a boron anion, but from the viewpoint of suppressing staining during development, at least one selected from the group consisting of inorganic cations, iodonium cations, and infrared absorbing dye cations is preferred.
• the counter cation may be used alone or in combination of two or more.
• M + represents Li + , Na + , K + , an iodonium cation, or an infrared absorbing dye cation.
• M + represents an iodonium cation, or an infrared absorbing dye cation.
• the combination is not particularly limited, but is preferably a combination of inorganic cations, a combination of iodonium cations, or a combination of infrared absorbing dye cations, and more preferably a combination of iodonium cations or a combination of infrared absorbing dye cations. This further improves the ability to suppress development defects over time and printing durability.
• the iodonium cation may be the cation moiety of an electron-accepting polymerization initiator described below
• the infrared absorbing dye cation may be the cation moiety of an infrared absorbing agent described below.
• the cationic moiety of the electron donating polymerization initiator and the cationic moiety of the infrared absorbing agent can bond with the anionic moiety of the borate compound represented by formula (1) to form a salt.
• inorganic cations examples include lithium cations, sodium cations, potassium cations, calcium cations, and magnesium cations. Among these, sodium cations, lithium cations, and potassium cations are preferred, and sodium cations are more preferred.
• the iodonium cation As the iodonium cation, the cation portion of the electron-accepting polymerization initiator described below can be used. A specific example is shown in the following structural formula. In the following structural formula, Me represents a methyl group. Note that the iodonium cation is not limited to the following specific example.
• the infrared absorbing dye cation As the infrared absorbing dye cation, the cation portion of the infrared absorbing agent described below can be used. A specific example is shown in the following structural formula. In the following structural formula, Me represents a methyl group, and Bu represents a butyl group. Note that the infrared absorbing dye cation is not limited to the following specific example.
• the highest occupied molecular orbital (HOMO) of the specific borate compound is preferably ⁇ 6.0 eV or more, more preferably ⁇ 5.95 eV or more, and even more preferably ⁇ 5.93 eV or more.
• the upper limit is preferably ⁇ 5.00 eV or less, more preferably ⁇ 5.40 eV or less, and particularly preferably ⁇ 5.93 eV to ⁇ 5.70 eV.
• the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are calculated by the following method.
• the quantum chemical calculation software Gaussian 09 is used, and structural optimization is performed by DFT (B3LYP/6-31G(d)).
• the MO energy Ebare (unit: heartree) obtained in the above MO energy calculation is converted to Escaled (unit: eV) used as the HOMO and LUMO values in this disclosure by the following formula.
• Escaled 0.823168 ⁇ 27.2114 ⁇ Ebare-1.07634 It should be noted that 27.2114 is simply a coefficient for converting heartree to eV, and 0.823168 and -1.07634 are adjustment coefficients that are determined so that the HOMO and LUMO of the compound to be calculated match the actually measured values.
• the image recording layer in embodiment B contains a borate compound represented by the following formula (1a).
• the borate compound represented by formula (1a) is one embodiment of the borate compound represented by formula (1), and is used as an electron-donating polymerization initiator in the image recording layer.
• R 1 , R 2 , R 3 and R 4 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted alkynyl group, and R 1 , R 2 , R 3 and R 4 each independently may have a ring structure. However, at least one of R 1 , R 2 , R 3 and R 4 is different from the others.
• Ma + represents an iodonium cation.
• R 1 , R 2 , R 3 and R 4 have the same meanings as R 1 , R 2 , R 3 and R 4 in formula (1), and preferred embodiments are also the same.
• Ma + represents an iodonium cation. That is, the iodonium cation is a counter cation of the boron anion.
• the iodonium cation is not particularly limited as long as it is a cation that can neutralize the boron anion.
• the iodonium cation may contain only one type, or may contain two or more types.
• iodonium cations examples include those shown by the structural formula described in the section on embodiment A above.
• the highest occupied molecular orbital (HOMO) of the borate compound represented by formula (1a) has the same preferred embodiment as the borate compound represented by formula (1) above.
• the calculation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is also performed in the same manner as above.
• Preferred specific examples of the borate compound represented by formula (1a) include, but are not limited to, the above-mentioned B-18, B-19, B-31 to B-33, B-45, and B-46.
• the image recording layer may contain only one type of specific borate compound, or may contain two or more types.
• the content of the specific borate compound is preferably 0.01% by mass to 30% by mass, more preferably 0.05% by mass to 25% by mass, and even more preferably 0.1% by mass to 20% by mass, as the weight of the anion portion of the specific borate compound, relative to the total mass of the image recording layer.
• the specific borate compound may be a synthetic product.
• a borate compound having a different structure may be by-produced.
• the obtained borate compound may contain small amounts of impurities derived from the solvent, catalyst, raw materials used, etc. According to the studies of the present inventors, even if the obtained borate compound contains at least one of a borate compound having a structure different from that of the target borate compound and impurities, the total content is very small. Therefore, it has been confirmed that even if the borate compound obtained by synthesis is directly applied to an image recording layer coating liquid without being subjected to a special purification step such as removing impurities, the performance of the obtained lithographic printing plate precursor is not affected.
• the image recording layer may contain at least one of borate compounds other than the specific borate compounds and impurities that are unavoidable in the manufacturing process.
• At least one of borate compounds other than the specific borate compounds and impurities that are unavoidable in the manufacturing process may include, for example, raw materials used, solvents, catalysts, by-products produced by synthesis reactions, borate compounds other than the specific borate compounds, etc.
• the image-recording layer in embodiment A of the present disclosure comprises an electron-accepting polymerization initiator.
• the image recording layer in embodiment B preferably contains an electron-accepting polymerization initiator.
• the electron-accepting polymerization initiator contained in the image recording layer in embodiment B does not include the borate compound represented by formula (1a).
• the electron-accepting polymerization initiator is a compound that generates a polymerization initiating species such as a radical by accepting one electron through intermolecular electron transfer when electrons of an infrared absorber are excited by exposure to infrared light.
• the electron-accepting polymerization initiator used in the present disclosure is a compound that generates a polymerization initiating species such as a radical or a cation by the energy of light, heat, or both, and can be appropriately selected from known thermal polymerization initiators, compounds having a bond with small bond dissociation energy, photopolymerization initiators, and the like.
• a radical polymerization initiator is preferable, and an onium salt compound is more preferable.
• the electron-accepting polymerization initiator is preferably an infrared-sensitive polymerization initiator.
• Examples of the electron-accepting radical polymerization initiator include (a) organic halides, (b) carbonyl compounds, (c) azo compounds, (d) organic peroxides, (e) metallocene compounds, (f) azide compounds, (g) hexaarylbiimidazole compounds, (i) disulfone compounds, (j) oxime ester compounds, and (k) onium salt compounds.
• the (a) organic halide for example, the compounds described in paragraphs 0022 to 0023 of JP-A-2008-195018 are preferable.
• the (b) carbonyl compound for example, the compounds described in paragraph 0024 of JP-A-2008-195018 are preferable.
• the azo compound (c) for example, the azo compounds described in JP-A-8-108621 can be used.
• the (d) organic peroxide for example, the compounds described in paragraph 0025 of JP-A-2008-195018 are preferable.
• the (e) metallocene compound for example, the compounds described in paragraph 0026 of JP-A-2008-195018 are preferable.
• azide compounds examples include 2,6-bis(4-azidobenzylidene)-4-methylcyclohexanone.
• hexaarylbiimidazole compound for example, the compounds described in paragraph 0027 of JP-A-2008-195018 are preferable.
• disulfone compound examples include the compounds described in JP-A-61-166544 and JP-A-2002-328465.
• oxime ester compound for example, the compounds described in paragraphs 0028 to 0030 of JP-A-2008-195018 are preferable.
• oxime ester compounds and onium salt compounds preferred from the viewpoint of curability.
• iodonium salt compounds, sulfonium salt compounds and azinium salt compounds preferred from the viewpoint of printing durability.
• iodonium salt compounds and sulfonium salt compounds preferred from the viewpoint of printing durability.
• iodonium salt compounds and sulfonium salt compounds preferred from the viewpoint of printing durability.
• iodonium salt compounds from the viewpoint of printing durability
• iodonium salt compounds, sulfonium salt compounds and azinium salt compounds more preferred are iodonium salt compounds and sulfonium salt compounds, and particularly preferred are iodonium salt compounds. Specific examples of these compounds are shown below, but the present disclosure is not limited thereto.
• iodonium salt compounds include diaryliodonium salt compounds, more preferably diphenyliodonium salt compounds substituted with electron-donating groups such as alkyl or alkoxy groups, and more preferably asymmetric diphenyliodonium salt compounds.
• diphenyliodonium hexafluorophosphate 4-methoxyphenyl-4-(2-methylpropyl)phenyliodonium hexafluorophosphate, 4-(2-methylpropyl)phenyl-p-tolyliodonium hexafluorophosphate, 4-hexyloxyphenyl-2,4,6-trimethoxyphenyliodonium hexafluorophosphate, 4-hexyloxyphenyl-2,4-diethoxyphenyliodonium tetrafluoroborate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium 1-perfluorobutanesulfonate, 4-octyloxyphenyl-2,4,6-trimethoxyphenyliodonium hexafluorophosphate, and bis(4-t-butylphenyl)iodonium hexafluorophosphate.
• sulfonium salt compounds include triarylsulfonium salt compounds, particularly triarylsulfonium salt compounds in which at least a portion of the electron-withdrawing groups, such as groups on the aromatic ring, are substituted with halogen atoms, and more preferably triarylsulfonium salt compounds in which the total number of halogen atoms substituted on the aromatic ring is 4 or more.
• triphenylsulfonium hexafluorophosphate triphenylsulfonium benzoylformate, bis(4-chlorophenyl)phenylsulfonium benzoylformate, bis(4-chlorophenyl)-4-methylphenylsulfonium tetrafluoroborate, tris(4-chlorophenyl)sulfonium 3,5-bis(methoxycarbonyl)benzenesulfonate, tris(4-chlorophenyl)sulfonium hexafluorophosphate, and tris(2,4-dichlorophenyl)sulfonium hexafluorophosphate.
• a sulfonamide anion or a sulfonimide anion is preferable, and a sulfonimide anion is more preferable.
• the sulfonamide anion is preferably an arylsulfonamide anion.
• the sulfonimide anion is preferably a bisarylsulfonimide anion. Specific examples of sulfonamide anions or sulfonimide anions are shown below, but the present disclosure is not limited thereto. In the following specific examples, Ph represents a phenyl group, Me represents a methyl group, and Et represents an ethyl group.
• the electron-accepting polymerization initiator preferably contains compound A represented by the following formula (Ia) and one or more compounds B selected from the group consisting of compounds represented by the following formula (Ib) or (Ic).
• R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkoxy group having 2 to 9 carbon atoms, at least one of R 3 and R 4 is different from R 1 or R 2 , the difference between the total number of carbon atoms in R 1 and R 2 and the total number of carbon atoms in R 3 and R 4 is 0 to 4 (i.e., 0, 1, 2, 3 or 4), the difference between the total number of carbon atoms in R 1 and R 2 and the total number of carbon atoms in R 5 and R 6 is 0 to 4, and X 1 , X 2 and X 3 are the same or different anions.
• R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently preferably a substituted or unsubstituted alkyl group having 2 to 9 carbon atoms, or a substituted or unsubstituted alkoxy group having 2 to 9 carbon atoms, more preferably a substituted or unsubstituted alkyl group having 3 to 6 carbon atoms, or a substituted or unsubstituted alkoxy group having 3 to 6 carbon atoms, and even more preferably a substituted or unsubstituted alkyl group having 3 to 6 carbon atoms.
• the alkyl group or alkoxy group may be either linear or branched, but is preferably branched.
• substituted or unsubstituted alkyl groups include ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n-pentyl, t-pentyl, sec-pentyl, neopentyl, n-hexyl, iso-hexyl, sec-hexyl, t-hexyl, n-heptyl, n-octyl, iso-octyl, 2-ethylhexyl, and n-nonyl.
• Examples of the substituted or unsubstituted alkoxy group include an ethoxy group, an n-propoxy group, an iso-propoxy group, a t-butoxy group, an n-butoxy group, and an n-octyloxy group.
• X 1 , X 2 and X 3 are preferably ClO 4 ⁇ , PF 6 ⁇ , BF 4 ⁇ , SbF 6 ⁇ , CH 3 SO 3 ⁇ , CF 3 SO 3 ⁇ , C 6 H 5 SO 3 ⁇ , CH 3 C 6 H 4 SO 3 ⁇ , HOC 6 H 4 SO 3 ⁇ , ClC 6 H 4 SO 3 ⁇ and a borate anion represented by the following structure (Id).
• R 1 , R 2 , R 3 and R 4 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group (including a halogen-substituted aryl group), a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted heterocyclic group.
• Two or more of R 1 , R 2 , R 3 and R 4 may be linked together to form a substituted or unsubstituted heterocycle containing a boron atom.
• the resulting heterocycle has a maximum of 7 carbon atoms, nitrogen atoms, oxygen atoms or nitrogen atoms.
• the substituents in R 1 , R 2 , R 3 and R 4 include a chlorine atom, a fluorine atom, a nitro group, an alkyl group, an alkoxy group and an acetoxy group.
• R 1 , R 2 , R 3 and R 4 are substituted or unsubstituted aryl groups, and it is more preferable that all of R 1 , R 2 , R 3 and R 4 are unsubstituted phenyl groups.
• At least one of X 1 , X 2 and X 3 is preferably a tetraarylborate anion containing the same or different aryl groups, more preferably one or more is a tetraphenylborate anion, and further preferably each of X 1 , X 2 and X 3 is a tetraphenylborate anion.
• a preferred embodiment is one in which compound B includes a compound represented by formula (Ic), R 1 is the same as R 5 , and R 2 is the same as R 6.
• R 1 is the same as R 2 , and for example, it is preferred that both R 1 and R 2 are an iso-propyl group, an iso-butyl group, or a t-butyl group.
• compound B includes a compound represented by formula (Ib), R 1 is the same as R 2 , and R 3 is the same as R 4.
• R 1 and R 2 are an iso-propyl group, an iso-butyl group, or a t-butyl group. It is also preferable that the difference in the number of carbon atoms between R 1 and R 3 is 1 or 2.
• Compound B may be a mixture of a compound represented by formula (Ib) and a compound represented by formula (Ic).
• the molar ratio of compound A to compound B is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 30:70 to 70:30.
• the electron-accepting polymerization initiator may contain a compound represented by formula (II) described in paragraphs 0186 to 0197 of WO 2022/019217.
• the lowest unoccupied molecular orbital (LUMO) of the electron-accepting polymerization initiator is preferably ⁇ 3.00 eV or less, and more preferably ⁇ 3.02 eV or less, from the viewpoints of improving sensitivity and preventing plate skipping.
• the lower limit is preferably ⁇ 3.80 eV or more, and more preferably ⁇ 3.60 eV or more.
• the electron-accepting polymerization initiator may be used alone or in combination of two or more kinds.
• the content of the electron-accepting polymerization initiator is preferably from 0.1% by mass to 50% by mass, more preferably from 0.5% by mass to 30% by mass, and particularly preferably from 0.8% by mass to 20% by mass, based on the total mass of the image recording layer.
• the image recording layer of the present disclosure preferably contains an infrared absorbing agent.
• the infrared absorbing agent is not particularly limited, and examples thereof include pigments and dyes.
• the dye to be used as the infrared absorber commercially available dyes and known dyes described in literature such as "Dye Handbook” (edited by the Organic Synthesis Chemistry Association, published in 1970) can be used.
• the dye examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complex dyes.
• cyanine dyes particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further examples include cyanine dyes and indolenine cyanine dyes. Of these, cyanine dyes are particularly preferred.
• the infrared absorbing agent is preferably a cationic polymethine dye having an oxygen or nitrogen atom at the meso position.
• cationic polymethine dyes include cyanine dyes, pyrylium dyes, thiopyrylium dyes, and azulenium dyes, and cyanine dyes are preferred from the standpoints of ease of availability and solubility in solvents during the introduction reaction.
• the cyanine dye include the compounds described in paragraphs 0017 to 0019 of JP-A-2001-133969, paragraphs 0016 to 0021 of JP-A-2002-023360, and paragraphs 0012 to 0037 of JP-A-2002-040638, preferably the compounds described in paragraphs 0034 to 0041 of JP-A-2002-278057 and paragraphs 0080 to 0086 of JP-A-2008-195018, particularly preferably the compounds described in paragraphs 0035 to 0043 of JP-A-2007-90850, and the compounds described in paragraphs 0105 to 0113 of JP-A-2012-206495.
• the compounds described in paragraphs 0008 to 0009 of JP-A No. 5-5005 and paragraphs 0022 to 0025 of JP-A No. 2001-222101 can also be preferably used.
• the compounds described in paragraphs 0072 to 0076 of JP-A-2008-195018 are preferred.
• the infrared absorbing agent preferably contains an infrared absorbing agent that decomposes upon exposure to infrared rays (a decomposable infrared absorbing agent), and more preferably contains a decomposable color-forming infrared absorbing agent. It is presumed that by using a decomposable infrared absorber as the infrared absorber, the infrared absorber or its decomposition products promote polymerization, and further, the decomposition products of the infrared absorber interact with the polymerizable compound, resulting in excellent printing durability.
• a decomposable infrared absorber as the infrared absorber, the infrared absorber or its decomposition products promote polymerization, and further, the decomposition products of the infrared absorber interact with the polymerizable compound, resulting in excellent printing durability.
• the decomposable infrared absorbent is preferably an infrared absorbent that has the function of absorbing infrared rays, decomposing, and developing color when exposed to infrared rays.
• the colored compound formed by the decomposable infrared absorber absorbing infrared light and decomposing when exposed to infrared light is also referred to as a "colored body of the decomposable infrared absorber.”
• the decomposable infrared absorbent preferably has a function of absorbing infrared rays upon exposure to infrared rays and converting the absorbed infrared rays into heat.
• the decomposable infrared absorbent may be one that absorbs and decomposes at least a part of light in the infrared wavelength region (wavelength 750 nm to 1 mm), but is preferably an infrared absorbent having a maximum absorption wavelength in the wavelength region of 750 nm to 1,400 nm, and more preferably an infrared absorbent having a maximum absorption wavelength in the wavelength region of 760 nm to 900 nm. More specifically, the decomposable infrared absorbent is preferably a compound that decomposes upon exposure to infrared light to produce a compound having a maximum absorption wavelength in the wavelength range of 500 nm to 600 nm.
• the decomposable infrared absorber is preferably an infrared absorber that decomposes due to heat, electron transfer, or both caused by infrared exposure, and more preferably an infrared absorber that decomposes due to electron transfer caused by infrared exposure.
• decomposes due to electron transfer means that electrons excited from the HOMO (highest occupied molecular orbital) of the decomposable infrared absorber to the LUMO (lowest unoccupied molecular orbital) by infrared exposure transfer intramolecularly to an electron-accepting group within the molecule (for example, a group with an electric potential close to that of the LUMO), resulting in decomposition.
• the infrared absorber preferably contains a compound represented by the following formula 1.
• R 1 and R 2 each independently represent a hydrogen atom or an alkyl group
• R 1 and R 2 may be bonded to each other to form a ring
• R 3 to R 6 each independently represent a hydrogen atom or an alkyl group
• R 7 and R 8 each independently represent an alkyl group or an aryl group
• Y 1 and Y 2 each independently represent an oxygen atom, a sulfur atom, -NR 0 - or a dialkylmethylene group
• R 0 represents a hydrogen atom, an alkyl group or an aryl group
• Ar 1 and Ar 2 each independently represent a group forming a benzene ring or naphthalene ring which may have a group represented by formula 2 described later
• a 1 represents -NR 9 R 10 , -X 1 -L 1 or a group represented by formula 2 described later
• R 9 and R 10 each independently represent an alkyl group, an aryl group, an alkoxycarbonyl group or an aryls
• Ar 1 and Ar 2 each independently represent a group forming a benzene ring or a naphthalene ring.
• the benzene ring and the naphthalene ring may have a substituent other than -X.
• substituents include an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, and a combination of these groups, and the like, but an alkyl group is preferable.
• at least one of Ar 1 and Ar 2 has a group represented by the above formula 2, and from the viewpoints of printing durability and visibility, it is preferable that both Ar 1 and Ar 2 have a group represented by the above formula 2.
• X2 represents a single bond or an oxygen atom, and is preferably an oxygen atom.
• R 11 and R 14 each independently represent an alkyl group or an aryl group, preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.
• R 12 , R 13 , R 15 and R 16 each independently represent a hydrogen atom, an alkyl group or an aryl group, preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and even more preferably an alkyl group having 1 to 12 carbon atoms.
• R 17 represents an alkyl group or an aryl group, preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.
• a 1 represents -NR 9 R 10 , -X 1 -L 1 or -X, and from the viewpoints of printing durability, visibility and stability over time, it is preferably -NR 9 R 10 or -X 1 -L 1 , and more preferably -NR 18 R 19 or -S-R 20 .
• A1 is preferably -X, more preferably a halogen atom, further preferably a chlorine atom or a bromine atom, and particularly preferably a chlorine atom.
• R 9 and R 10 each independently represent an alkyl group, an aryl group, an alkoxycarbonyl group, or an arylsulfonyl group, preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms.
• X 1 represents an oxygen atom or a sulfur atom.
• L 1 is a hydrocarbon group or a heteroaryl group, it is preferably a sulfur atom, and L 1 is preferably a group whose bond to X 1 is cleaved by exposure to heat or infrared light.
• L1 represents a hydrocarbon group, a heteroaryl group, or a group whose bond to X1 is cleaved by heat or infrared exposure.
• L1 is preferably a hydrocarbon group or a heteroaryl group, more preferably an aryl group or a heteroaryl group, and even more preferably a heteroaryl group.
• L 1 is preferably a group whose bond with X 1 is cleaved by exposure to heat or infrared rays. The group whose bond to X 1 is cleaved by exposure to heat or infrared rays will be described later.
• R 18 and R 19 each independently represent an aryl group, preferably an aryl group having 6 to 20 carbon atoms, and more preferably a phenyl group.
• R 20 represents a hydrocarbon group or a heteroaryl group, preferably an aryl group or a heteroaryl group, and more preferably a heteroaryl group.
• heteroaryl group for L1 and R20 include the following groups.
• the alkyl group in R 1 to R 10 and R 0 is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and further preferably an alkyl group having 1 to 10 carbon atoms.
• the alkyl group may be linear, branched, or have a ring structure.
• Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, an isopropyl group, an isobutyl group, a s-butyl group, a t-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl group
• the alkyl group may have a substituent.
• substituents include an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and combinations of these groups.
• the aryl group for R 9 , R 10 , R 18 , R 19 and R 0 is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms.
• the aryl group may have a substituent, for example, an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, or a combination thereof.
• a substituent for example, an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, or a combination thereof.
• aryl group examples include a phenyl group, a naphthyl group, a p-tolyl group, a p-chlorophenyl group, a p-fluorophenyl group, a p-methoxyphenyl group, a p-dimethylaminophenyl group, a p-methylthiophenyl group, and a p-phenylthiophenyl group.
• a phenyl group, a p-methoxyphenyl group, a p-dimethylaminophenyl group, or a naphthyl group is preferred.
• R 1 and R 2 are linked to form a ring.
• the number of ring members is preferably 5 or 6, more preferably 6.
• the ring formed by linking R1 and R2 is preferably a hydrocarbon ring which may have an ethylenically unsaturated bond.
• Y 1 and Y 2 each independently represent an oxygen atom, a sulfur atom, -NR 0 - or a dialkylmethylene group, preferably -NR 0 - or a dialkylmethylene group, more preferably a dialkylmethylene group.
• R 0 represents a hydrogen atom, an alkyl group or an aryl group, and is preferably an alkyl group.
• R 7 and R 8 are the same group.
• R7 and R8 are each preferably independently a straight-chain alkyl group or an alkyl group having a terminal sulfonate group, and more preferably a methyl group, an ethyl group, or a butyl group having a terminal sulfonate group.
• the counter cation of the sulfonate group may be the cation on the nitrogen atom in formula 1, or may be an alkali metal cation or an alkaline earth metal cation.
• R7 and R8 are each independently preferably an alkyl group having an anionic structure, more preferably an alkyl group having a carboxylate group or a sulfonate group, and further preferably an alkyl group having a sulfonate group at the terminal.
• R 7 and R 8 are each preferably independently an alkyl group having an aromatic ring, more preferably an alkyl group having an aromatic ring at a terminal, and particularly preferably a 2-phenylethyl group, a 2-naphthalenylethyl group, or a 2-(9-anthracenyl)ethyl group.
• R 3 to R 6 each independently represent a hydrogen atom or an alkyl group, and are preferably a hydrogen atom.
• the compound represented by formula 1 preferably has one or more halogen atoms, more preferably has one or more halogen atoms in at least one selected from the group consisting of A 1 , Ar 1 and Ar 2, and particularly preferably has one or more halogen atoms in each of A 1 , Ar 1 and Ar 2 .
• the compound represented by Formula 1 more preferably has two or more halogen atoms, even more preferably has three or more halogen atoms, and particularly preferably has three or more and six or less halogen atoms.
• the halogen atom is preferably a chlorine atom or a bromine atom.
• the compound represented by formula 1 preferably has a halogen atom in at least one of Ar 1 and Ar 2 , more preferably has a chlorine atom or a bromine atom in at least one of Ar 1 and Ar 2 , and particularly preferably has a bromine atom in at least one of Ar 1 and Ar 2 .
• Za represents a counter ion that neutralizes the charge, and when it represents an anion species, examples thereof include a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a perchlorate ion, a sulfonamide anion, a sulfonimide anion, etc.
• an alkali metal ion, an alkaline earth metal ion, an ammonium ion, a pyridinium ion, or a sulfonium ion is preferred, a sodium ion, a potassium ion, an ammonium ion, a pyridinium ion, or a sulfonium ion is more preferred, a sodium ion, a potassium ion, or an ammonium ion is even more preferred, and a sodium ion, a potassium ion, or a trialkylammonium ion is particularly preferred.
• Za is preferably an organic anion containing a carbon atom, more preferably a sulfonate ion, a carboxylate ion, a sulfonamide anion, or a sulfonimide anion, even more preferably a sulfonamide anion or a sulfonimide anion, and particularly preferably a sulfonimide anion.
• R 1 to R 8 , R 0 , A 1 , Ar 1 , Ar 2 , Y 1 and Y 2 may have an anionic structure or a cationic structure.
• Za is a monovalent counter anion.
• R 1 to R 8 , R 0 , A 1 , Ar 1 , Ar 2 , Y 1 and Y 2 have two or more anionic structures
• Za can also be a counter cation.
• the moieties other than Za are electrically neutral, Za may be omitted.
• the sulfonamide anion is preferably an arylsulfonamide anion.
• the sulfonimide anion is preferably a bisarylsulfonimide anion.
• Specific examples of sulfonamide anions or sulfonimide anions are shown below, but the present disclosure is not limited thereto. In the following specific examples, Ph represents a phenyl group, Me represents a methyl group, and Et represents an ethyl group.
• the group whose bond to X1 is cleaved by exposure to heat or infrared light is preferably a group represented by any one of the following formulas (1-1) to (1-7), and more preferably a group represented by any one of the following formulas (1-1) to (1-3).
• ⁇ represents a bonding site with X 1 in formula 1;
• R 10 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, -OR 14 , -NR 15 R 16 or -SR 17 ;
• R 11 each independently represents a hydrogen atom, an alkyl group or an aryl group;
• R 12 represents an aryl group, -OR 14 , -NR 15 R 16 , -SR 17 , -C( ⁇ O)R 18 , -OC( ⁇ O)R 18 or a halogen atom;
• R 13 represents an aryl group, an alkenyl group, an alkoxy group or an onium group;
• R 14 to R 17 each independently represent a hydrogen atom, an alkyl group or an aryl group;
• R 18 each independently represents an alkyl group, an aryl group, -OR 14 , -NR 15 R 16 or -SR 17 , and
• Z 1 represents
• R 10 , R 11 and R 14 to R 18 are alkyl groups
• the preferred embodiments are the same as the preferred embodiments of the alkyl groups in R 2 to R 9 and R 0 .
• the alkenyl group for R 10 and R 13 preferably has 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 10 carbon atoms.
• R 10 to R 18 are aryl groups
• the preferred embodiments are the same as the preferred embodiments of the aryl group for R 0 .
• R 10 in formula (1-1) is preferably an alkyl group, an alkenyl group, an aryl group, -OR 14 , -NR 15 R 16 , or -SR 17 , more preferably an alkyl group, -OR 14 , -NR 15 R 16 , or -SR 17 , even more preferably an alkyl group or -OR 14 , and particularly preferably -OR 14 .
• the alkyl group is preferably an alkyl group having an arylthio group or an alkyloxycarbonyl group at the ⁇ -position.
• R 14 is preferably an alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, further preferably an isopropyl group or a t-butyl group, and particularly preferably a t-butyl group.
• R 11 in formula (1-2) is preferably a hydrogen atom.
• R 14 is preferably an alkyl group.
• R 11 in formula (1-3) is each independently a hydrogen atom or an alkyl group, and it is more preferable that at least one R 11 in formula (1-3) is an alkyl group.
• the alkyl group for R 11 is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 3 to 10 carbon atoms.
• the alkyl group for R 11 is preferably a branched alkyl group or a cycloalkyl group, more preferably a secondary or tertiary alkyl group or a cycloalkyl group, and further preferably an isopropyl group, a cyclopentyl group, a cyclohexyl group, or a t-butyl group.
• R 13 in formula (1-3) is preferably an aryl group, an alkoxy group or an onium group, more preferably a p-dimethylaminophenyl group or a pyridinium group, and even more preferably a pyridinium group.
• Examples of the onium group in R 13 include a pyridinium group, an ammonium group, and a sulfonium group.
• the onium group may have a substituent.
• substituent include an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a sulfo group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and a group formed by combining these groups.
• an alkyl group, an aryl group, and a group formed by combining these groups are preferred.
• a pyridinium group is preferred, and examples thereof include an N-alkyl-3-pyridinium group, an N-benzyl-3-pyridinium group, an N-(alkoxypolyalkyleneoxyalkyl)-3-pyridinium group, an N-alkoxycarbonylmethyl-3-pyridinium group, an N-alkyl-4-pyridinium group, an N-benzyl-4-pyridinium group, an N-(alkoxypolyalkyleneoxyalkyl)-4-pyridinium group, and an N-alkoxycarbonylmethyl-4-pyridinium group.
• N-alkyl-3,5-dimethyl-4-pyridinium group is more preferred, an N-alkyl-3-pyridinium group or an N-alkyl-4-pyridinium group is even more preferred, an N-methyl-3-pyridinium group, an N-octyl-3-pyridinium group, an N-methyl-4-pyridinium group or an N-octyl-4-pyridinium group is particularly preferred, and an N-octyl-3-pyridinium group or an N-octyl-4-pyridinium group is most preferred.
• examples of the counter anion include a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, a perchlorate ion, and the like, with the p-toluenesulfonate ion or the hexafluorophosphate ion being preferred.
• R 10 in formula (1-4) is preferably an alkyl group or an aryl group, and it is more preferable that one of the two R 10 is an alkyl group and the other is an aryl group.
• R 10 in formula (1-5) is preferably an alkyl group or an aryl group, more preferably an aryl group, and further preferably a p-methylphenyl group.
• R 10 in formula (1-6) is preferably each independently an alkyl group or an aryl group, and more preferably a methyl group or a phenyl group.
• Z 1 in formula (1-7) may be any counter ion that neutralizes the charge, and the compound as a whole may be included in the above Za.
• Z1 is preferably a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, or a perchlorate ion, and more preferably a p-toluenesulfonate ion or a hexafluorophosphate ion.
• the group whose bond to X1 is cleaved by exposure to heat or infrared rays is particularly preferably a group represented by formula (1-8).
• ⁇ represents a bonding site with X1 in formula 1
• R 19 and R 20 each independently represent an alkyl group
• Za′ represents a counter ion that neutralizes the charge.
• the bonding position between the pyridinium ring and the hydrocarbon group containing R 20 is preferably the 3- or 4-position of the pyridinium ring, and more preferably the 4-position of the pyridinium ring.
• the alkyl group in R 19 and R 20 may be linear, branched, or have a ring structure.
• the alkyl group may have a substituent, and preferred examples of the substituent include an alkoxy group and a terminal alkoxypolyalkyleneoxy group.
• R 19 is preferably an alkyl group having 1 to 12 carbon atoms, more preferably a linear alkyl group having 1 to 12 carbon atoms, even more preferably a linear alkyl group having 1 to 8 carbon atoms, and particularly preferably a methyl group or an n-octyl group.
• R 20 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 8 carbon atoms, further preferably an isopropyl group or a t-butyl group, and particularly preferably an isopropyl group.
• Za' may be any counter ion that neutralizes the charge, and the compound as a whole may be included in the above Za.
• Za' is preferably a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, or a perchlorate ion, and more preferably a p-toluenesulfonate ion or a hexafluorophosphate ion.
• the decomposable infrared absorber is preferably a cyanine dye having a group that decomposes upon exposure to infrared light (specifically, R 1 in the following formulas 1-1 to 1-7).
• the decomposable infrared absorbing agent is more preferably a compound represented by the following formula 1-1.
• R 1 represents a group represented by any one of formulas 2-1 to 4-1 below;
• R 11 to R 18 each independently represent a hydrogen atom, a halogen atom, -R a , -OR b , -SR c , or -NR d R e , and R a to R e each independently represent a hydrocarbon group;
• a 1 , A 2 and a plurality of R 11 to R 18 may be linked to form a monocycle or polycycle;
• a 1 and A 2 each independently represent an oxygen atom, a sulfur atom, or a nitrogen atom;
• n 11 and n 12 each independently represent an integer of 0 to 5, with the proviso that the sum of n 11 and n 12 is 2 or more;
• n 13 and n 14 each independently represent 0 or 1;
• L represents an oxygen atom, a sulfur atom, or -NR 10 -;
• 10 represents a hydrogen atom, an alkyl group, or an aryl
• R 20 , R 30 , R 41 and R 42 each independently represent an alkyl group or an aryl group
• Zb represents a counter ion that neutralizes the charge
• the wavy line represents a bonding site with the group represented by L in formula 1-1 above.
• R 1 represents a group represented by any one of formulas 2-1 to 4-1 above.
• the group represented by formula 2-1, the group represented by formula 3-1, and the group represented by formula 4-1 will each be described below.
• R 20 represents an alkyl group or an aryl group, and the wavy line portion represents the bonding site with the group represented by L in formula 1-1.
• the alkyl group represented by R 20 is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.
• the alkyl group may be linear, branched, or have a ring structure.
• the aryl group represented by R 20 is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms. From the viewpoint of visibility, R 20 is preferably an alkyl group.
• the alkyl group represented by R20 is preferably a secondary alkyl group or a tertiary alkyl group, and more preferably a tertiary alkyl group. Furthermore, from the viewpoints of decomposability and visibility, the alkyl group represented by R 20 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms, and even more preferably a branched alkyl group having 3 to 6 carbon atoms, particularly preferably an isopropyl group or a tert-butyl group, and most preferably a tert-butyl group.
• ⁇ represents the bonding site with the group represented by L in formula 1-1.
• R 30 represents an alkyl group or an aryl group, and the wavy line portion represents the bonding site with the group represented by L in formula 1-1.
• the alkyl group and aryl group represented by R 30 are the same as the alkyl group and aryl group represented by R 20 in formula 2-1, and preferred embodiments are also the same.
• the alkyl group represented by R 30 is preferably a secondary alkyl group or a tertiary alkyl group, and more preferably a tertiary alkyl group.
• the alkyl group represented by R 30 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms, and even more preferably a branched alkyl group having 3 to 6 carbon atoms, particularly preferably an isopropyl group or a tert-butyl group, and most preferably a tert-butyl group.
• the alkyl group represented by R 30 is preferably a substituted alkyl group, more preferably a fluoro-substituted alkyl group, further preferably a perfluoroalkyl group, and particularly preferably a trifluoromethyl group.
• the aryl group represented by R 30 is preferably a substituted aryl group, and examples of the substituent include an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms) and an alkoxy group (preferably an alkoxy group having 1 to 4 carbon atoms).
• ⁇ represents the bonding site with the group represented by L in formula 1-1.
• R 41 and R 42 each independently represent an alkyl group or an aryl group
• Zb represents a counter ion that neutralizes the charge
• the wavy line portion represents a bonding site with the group represented by L in formula 1-1.
• the alkyl group and aryl group represented by R 41 or R 42 are the same as the alkyl group and aryl group represented by R 20 in formula 2-1, and preferred embodiments are also the same.
• R 41 is preferably an alkyl group.
• R 42 is preferably an alkyl group.
• the alkyl group represented by R 41 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group.
• the alkyl group represented by R 42 is preferably a secondary alkyl group or a tertiary alkyl group, and more preferably a tertiary alkyl group.
• the alkyl group represented by R 42 is preferably an alkyl group having 1 to 8 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms, and even more preferably a branched alkyl group having 3 to 6 carbon atoms, particularly preferably an isopropyl group or a tert-butyl group, and most preferably a tert-butyl group.
• Zb in formula 4-1 may be any counter ion for neutralizing the charge, and the compound as a whole may be included in Za in formula 1-1.
• Zb is preferably a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, or a perchlorate ion, and more preferably a tetrafluoroborate ion or a hexafluorophosphate ion.
• ⁇ represents the bonding site with the group represented by L in formula 1-1.
• L is preferably an oxygen atom or —NR 10 —, and particularly preferably an oxygen atom.
• R 10 in -NR 10 - is preferably an alkyl group.
• the alkyl group represented by R 10 is preferably an alkyl group having 1 to 10 carbon atoms.
• the alkyl group represented by R 10 may be linear, branched, or have a ring structure. Among the alkyl groups, a methyl group or a cyclohexyl group is preferred.
• R 10 in —NR 10 — is an aryl group, it is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms.
• these aryl groups may have a substituent.
• R 11 to R 18 each independently represent a hydrogen atom, -R a , -OR b , -SR c , or -NR d R e .
• the hydrocarbon groups represented by R a to R e are preferably hydrocarbon groups having 1 to 30 carbon atoms, more preferably hydrocarbon groups having 1 to 15 carbon atoms, and even more preferably hydrocarbon groups having 1 to 10 carbon atoms.
• the hydrocarbon group may be linear, branched, or have a ring structure. As the above-mentioned hydrocarbon group, an alkyl group is particularly preferred.
• the alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.
• the alkyl group may be linear, branched, or have a ring structure.
• Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, an isopropyl group, an isobutyl group, a s-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl
• the alkyl group may have a substituent.
• substituents include an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and combinations thereof.
• R 11 to R 14 are each preferably independently a hydrogen atom or -R a (i.e., a hydrocarbon group), more preferably a hydrogen atom or an alkyl group, and further preferably a hydrogen atom, except for the following cases: Among them, R 11 and R 13 bonded to the carbon atom bonded to the carbon atom bonded to L are preferably alkyl groups, and more preferably they are bonded to form a ring. The ring formed may be a monocyclic ring or a polycyclic ring.
• the ring formed include monocyclic rings such as a cyclopentene ring, a cyclopentadiene ring, a cyclohexene ring, and a cyclohexadiene ring, and polycyclic rings such as an indene ring and an indole ring.
• R 12 bonded to the carbon atom to which A 1 + is bonded is bonded to R 15 or R 16 (preferably R 16 ) to form a ring
• R 14 bonded to the carbon atom to which A 2 is bonded is bonded to R 17 or R 18 (preferably R 18 ) to form a ring.
• n 13 is 1 and R 16 is --R a (ie, a hydrocarbon group).
• R 16 is preferably linked to R 12 bonded to the carbon atom to which A 1 + is bonded to form a ring.
• the ring formed is preferably an indolium ring, a pyrylium ring, a thiopyrylium ring, a benzoxazoline ring, or a benzoimidazoline ring, and from the viewpoint of improving the visibility of the exposed portion, an indolium ring is more preferable. These rings may further have a substituent.
• n 14 is 1 and R 18 is --R a (ie, a hydrocarbon group).
• R 18 is preferably linked to R 14 , which is bonded to the carbon atom to which A 2 is bonded, to form a ring.
• the ring formed is preferably an indole ring, a pyran ring, a thiopyran ring, a benzoxazole ring, or a benzimidazole ring, and from the viewpoint of improving the visibility of the exposed portion, an indole ring is more preferable. These rings may further have a substituent.
• R 16 and R 18 are preferably the same group, and when they each form a ring, they preferably form a ring of the same structure, except for A 1 + and A 2 .
• R 15 and R 17 are preferably the same group. Furthermore, R 15 and R 17 are preferably -R a (i.e., a hydrocarbon group), more preferably an alkyl group, and further preferably a substituted alkyl group.
• R 15 and R 17 are preferably -R a (i.e., a hydrocarbon group), more preferably an alkyl group, and further preferably a substituted alkyl group.
• R 15 and R 17 are preferably a substituent alkyl group.
• Examples of the substituted alkyl group represented by R 15 or R 17 include groups represented by any one of the following formulae (a1) to (a4).
• R W0 represents an alkylene group having 2 to 6 carbon atoms
• W represents a single bond or an oxygen atom
• n W1 represents an integer from 1 to 45
• R W5 represents an alkyl group having 1 to 12 carbon atoms
• R W2 to R W4 each independently represent a single bond or an alkylene group having 1 to 12 carbon atoms
• M represents a hydrogen atom, a sodium atom, a potassium atom, or an onium group.
• alkylene group represented by R W0 examples include an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an isobutylene group, an n-pentylene group, an isopentylene group, an n-hexyl group, and an isohexyl group.
• an ethylene group, an n-propylene group, an isopropylene group, or an n-butylene group is preferred, and an n-propylene group is particularly preferred.
• n W1 is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3.
• alkyl group represented by R W1 examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-octyl group, and an n-dodecyl group.
• a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.
• the alkyl group represented by R W5 is the same as the alkyl group represented by R W1 , and preferred embodiments thereof are also the same as the preferred embodiments of the alkyl group represented by R W1 .
• Me represents a methyl group
• Et represents an ethyl group
• * represents a bonding site
• alkylene group represented by R W2 to R W4 include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an isobutylene group, an n-pentylene group, an isopentylene group, an n-hexyl group, an isohexyl group, an n-octylene group, and an n-dodecylene group.
• An ethylene group, an n-propylene group, an isopropylene group, or an n-butylene group is preferred, and an ethylene group or an n-propylene group is particularly preferred.
• the two M's may be the same or different.
• examples of the onium group represented by M include an ammonium group, an iodonium group, a phosphonium group, and a sulfonium group.
• CO 2 M in formula (a2), PO 3 M 2 in formula (a2), and SO 3 M in formula (a4) may each have an anionic structure in which M is dissociated.
• the counter cation of the anionic structure may be A 1 + or a cation that can be included in R 1 -L in formula 1-1.
• n 11 and n 12 are preferably the same, and each is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, further preferably 1 or 2, and particularly preferably 2.
• a 1 and A 2 each independently represent an oxygen atom, a sulfur atom, or a nitrogen atom, and preferably a nitrogen atom. In formula 1-1, A 1 and A 2 are preferably the same atom.
• Za in formula 1-1 represents a counter ion that neutralizes the charge.
• Za becomes a monovalent counter anion.
• R 11 to R 18 and R 1 -L may have an anionic structure or a cationic structure, and for example, when R 11 to R 18 and R 1 -L have two or more anionic structures, Za can also become a counter cation. If the cyanine dye represented by formula 1-1 has a structure in which the entire compound, except for Za, is charge-neutral, Za is not necessary.
• Za is a counter anion
• examples of the counter anion include a sulfonate ion, a carboxylate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a p-toluenesulfonate ion, a perchlorate ion, and the like, with the tetrafluoroborate ion being preferred.
• examples of the counter cation include an alkali metal ion, an alkaline earth metal ion, an ammonium ion, a pyridinium ion, and a sulfonium ion.
• a sodium ion, a potassium ion, an ammonium ion, a pyridinium ion, or a sulfonium ion is preferred, and a sodium ion, a potassium ion, or an ammonium ion is more preferred.
• the decomposable infrared absorbing agent is a compound represented by the following formula 1-2 (i.e., a cyanine dye).
• R 1 represents a group represented by any one of formulas 2-1 to 4-1 above;
• R 19 to R 22 each independently represent a hydrogen atom, a halogen atom, -R a , -OR b , -CN, -SR c , or -NR d R e ;
• R 23 and R 24 each independently represent a hydrogen atom or -R a ;
• R a to R e each independently represent a hydrocarbon group;
• R 19 and R 20 , R 21 and R 22 , or R 23 and R 24 may be linked to form a monocyclic or polycyclic ring;
• L represents an oxygen atom, a sulfur atom, or -NR 10 -;
• R 10 represents a hydrogen atom, an alkyl group, or an aryl group;
• Each of 2 independently represents an alkyl group which may have a substituent, and Za represents a counter ion
• R 1 in formula 1-2 has the same meaning as R 1 in formula 1-1, and the preferred embodiments are also the same.
• R 19 to R 22 each independently represent a hydrogen atom, a halogen atom, —R a , —OR b , or —CN. More specifically, R 19 and R 21 are preferably a hydrogen atom or -R a . Furthermore, R 20 and R 22 are preferably a hydrogen atom, —R a , —OR b , or —CN. -R a represented by R 19 to R 22 is preferably an alkyl group or an alkenyl group. When all of R 19 to R 22 are -R a , it is preferred that R 19 and R 20 , and R 21 and R 22 are linked to form a monocycle or polycycle. Examples of the ring formed by combining R 19 and R 20 or R 21 and R 22 include a benzene ring and a naphthalene ring.
• R 23 and R 24 are preferably linked to form a monocyclic or polycyclic ring.
• the ring formed by combining R23 and R24 may be a monocyclic ring or a polycyclic ring.
• Specific examples of the ring formed include monocyclic rings such as a cyclopentene ring, a cyclopentadiene ring, a cyclohexene ring, and a cyclohexadiene ring, and polycyclic rings such as an indene ring.
• R d1 to R d4 are preferably unsubstituted alkyl groups, and R d1 to R d4 are preferably the same group.
• the unsubstituted alkyl group includes unsubstituted alkyl groups having 1 to 4 carbon atoms, and among these, a methyl group is preferable.
• W 1 and W 2 are preferably each independently a substituted alkyl group from the viewpoint of increasing the water solubility of the compound represented by formula 1-2.
• the substituted alkyl group represented by W 1 and W 2 includes groups represented by any one of formulas (a1) to (a4) in formula 1-1, and preferred embodiments are the same.
• W1 and W2 are each independently an alkyl group having a substituent, and that the substituent is at least —OCH 2 CH 2 —, a sulfo group, a salt of a sulfo group, a carboxy group, or a salt of a carboxy group.
• Za represents a counter ion that neutralizes the charge in the molecule.
• R 19 to R 22 , R 23 to R 24 , R d1 to R d4 , W 1 , W 2 , and R 1 -L are groups with neutral charges, Za becomes a monovalent counter anion.
• R 19 to R 22 , R 23 to R 24 , R d1 to R d4 , W 1 , W 2 , and R 1 -L may have an anionic structure or a cationic structure, and for example, when R 19 to R 22 , R 23 to R 24 , R d1 to R d4 , W 1 , W 2 , and R 1 -L have two or more anionic structures, Za can also become a counter cation.
• Za when the compound represented by formula 1-2 has a structure in which the entire compound, except for Za, is electrically neutral, Za is not necessary.
• Z a when it is a counter anion are the same as Z a in formula 1-1, and preferred embodiments are also the same.
• Examples of Z a when it is a counter cation are the same as Z a in formula 1-1, and preferred embodiments are also the same.
• the cyanine dye as the decomposable infrared absorber is more preferably a compound represented by any one of the following formulas 1-3 to 1-7.
• a compound represented by any one of formulas 1-3, 1-5, and 1-6 is preferred.
• R 1 represents a group represented by any one of formulas 2-1 to 4-1 above;
• R 19 to R 22 each independently represent a hydrogen atom, a halogen atom, -R a , -OR b , -CN, -SR c , or -NR d R e ;
• R 25 and R 26 each independently represent a hydrogen atom, a halogen atom, or -R a ;
• R a to R e each independently represent a hydrocarbon group;
• R 19 and R 20 , R 21 and R 22 , or R 25 and R 26 may be linked to form a monocyclic or polycyclic ring;
• L represents an oxygen atom, a sulfur atom, or -NR 10 -;
• R 10 represents a hydrogen atom, an alkyl group, or an aryl group;
• Each of 2 independently represents an alkyl group which may have a substituent,
• R 1 , R 19 to R 22 , R d1 to R d4 , W 1 , W 2 , and L in formulas 1-3 to 1-7 have the same meanings as R 1 , R 19 to R 22 , R d1 to R d4 , W 1 , W 2 , and L in formula 1-2, and preferred embodiments are also the same.
• R 25 and R 26 each independently represent preferably a hydrogen atom or an alkyl group, more preferably an alkyl group, and particularly preferably a methyl group.
• cyanine dyes that are decomposable infrared absorbers are given below, but the present disclosure is not limited to these.
• the infrared absorber contains a compound represented by the following formula (X) as a decomposable infrared absorber.
• Ar 11 and Ar 12 each independently represent a substituted or unsubstituted aromatic ring or an atomic group necessary for forming a substituted or unsubstituted heteroaromatic ring;
• R 11 and R 12 each independently represent a substituted or unsubstituted alkyl group;
• R 13 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;
• R 14 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group;
• Y each independently represents an oxygen atom, a sulfur atom, or a dialkylmethylene group represented by >C(R 15 R 16 );
• R 15 and R 16 each independently represent a substituted or unsubstituted alkyl group having 1
• Ar 11 and Ar 12 each independently represent an atomic group necessary for forming a substituted or unsubstituted aromatic ring, or a substituted or unsubstituted heteroaromatic ring.
• substituent of the aromatic ring or heteroaromatic ring include an alkyl group, an alkoxy group, a halogen atom, a cyano group, a -COOR group, a -SO 3 R group, or a -SO 2 R group (R represents a substituted or unsubstituted alkyl group), and an alkyl group or a halogen atom is preferable.
• Ar 11 and Ar 12 are preferably an atomic group necessary for forming a substituted or unsubstituted aromatic ring, and more preferably an atomic group necessary for forming a substituted or unsubstituted benzene ring or naphthalene ring.
• the Y's are preferably each independently a dialkylmethylene group represented by >C(R 15 R 16 ), and more preferably, R 15 and R 16 are the same dialkylmethylene group represented by >C(R 15 R 16 ).
• R 15 and R 16 are each preferably independently a substituted or unsubstituted alkyl group having 1 or 2 carbon atoms.
• the above Y is particularly preferably a dialkylmethylene group represented by >C(R 15 R 16 ) in which R 15 and R 16 are methyl groups.
• R 11 and R 12 are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms.
• R 11 and R 12 may contain an ether bond or an ester bond in the middle of the carbon chain of the substituted or unsubstituted alkyl group having 1 to 12 carbon atoms.
• R 13 is preferably a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, and more preferably a haloalkyl group in which one or more of the hydrogen atoms in the alkyl group having 1 to 12 carbon atoms are substituted with a halogen atom.
• preferred examples of the halogen atom include a chlorine atom or a bromine atom.
• R 11 and R 12 each independently represent a perfluoroalkyl group.
• R 14 is preferably a hydrogen atom or an unsubstituted alkyl group having 1 or 8 carbon atoms.
• A1 and A2 each independently represent a substituted or unsubstituted alkyl group, or an atomic group containing 2 or 3 carbon atoms necessary to form a cyclopentene ring or a cyclohexene ring by bonding with each other.
• Za is a counter anion, it is preferably an anion containing a halogen atom or an anion containing a boron atom.
• Specific examples of Za include ClO 4 - , PF 6 - , BF 4 - , SbF 6 - , CH 3 SO 3 - , CF 3 SO 3 - , C 6 H 5 SO 3 - , CH 3 C 6 H 5 SO 3 - , HOC 6 H 5 SO 3 - , ClC 6 H 5 SO 3 - , CH 3 C 6 H 5 SO 3 - , and tetraarylborate anion (e.g., tetraphenylborate anion).
• Za is a counter cation
• examples of such cations include alkali metal ions, alkaline earth metal ions, tertiary ammonium ions, quaternary ammonium ions, onium ions (iodonium ions, sulfonium ions, phosphonium ions, etc.), etc.
• the decomposable infrared absorber preferably contains a compound represented by the following formula (P1):
• R P1 represents a group represented by formula (P2) or formula (P3) below
• R P2 and R P3 each independently represent a hydrogen atom or an alkyl group
• R P2 and R P3 may be bonded to each other to form a ring
• Ar P1 and Ar P2 each independently represent a benzene ring or a naphthalene ring
• Y P1 and Y P2 each independently represent an oxygen atom, a sulfur atom, -NR P0 - or a dialkylmethylene group
• R P4 and R P5 each independently represent an alkyl group
• R P6 to RP 9 each independently represent a hydrogen atom or an alkyl group
• R P0 represents a hydrogen atom, an alkyl group, or an aryl group
• Za represents a counter ion that neutralizes the charge.
• R P10 represents a monovalent organic group having an aryl group
• R P11 to R P14 and R P17 to R P20 each independently represent a hydrogen atom, an alkyl group, an aryl group, a hydroxyl group, an alkoxy group, or a halogen atom
• R P15 and R P16 each independently represent a hydrogen atom, an alkyl group, or an aryl group
• at least two of R P11 to R P20 may be bonded to form a ring structure
• * represents a single bond bonded to the oxygen atom in formula (P1).
• the compound represented by formula (P1) has the property of decomposing by heat or infrared energy to generate a highly visible colored body.
• coloring means that the color becomes stronger after heating or infrared exposure compared to before heating or infrared exposure, or the absorption becomes shorter wavelength and has absorption in the visible light region.
• the compound represented by formula (P1) is a compound that decomposes by heat or infrared exposure, and the absorption in the visible light region increases or the absorption becomes shorter wavelength and has absorption in the visible light region compared to before heating or infrared exposure. It is preferable that the compound represented by formula (P1) is a compound that decomposes by heat or infrared exposure to generate a compound with a maximum absorption wavelength at 500 nm to 600 nm.
• R P1 is preferably a group represented by the above formula (P2).
• the aryl group for R P10 is preferably an aryl group having 6 to 30 carbon atoms (also referred to as "number of carbon atoms"), more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms.
• the aryl group in R P10 is preferably an aryl group having one or more substituents on the aromatic ring, more preferably a phenyl group having one or more substituents on the aromatic ring, even more preferably a phenyl group having one or more alkyl groups on the aromatic ring, and particularly preferably an alkylphenyl group.
• R P10 is preferably an arylalkyl group having one or more substituents on the aromatic ring, more preferably a benzyl group having one or more substituents on the aromatic ring, still more preferably a benzyl group having one or more substituents (a substituted benzyl group), and particularly preferably a benzyl group having an alkyl group on the benzene ring.
• R P10 is preferably a group represented by formula (P4).
• X P2 represents a single bond or an alkylene group
• Ar P3 represents an aryl group
• X P2 is preferably an alkylene group, more preferably an alkylene group having 1 to 6 carbon atoms, even more preferably an alkylene group having 1 to 3 carbon atoms, particularly preferably an alkylene group having 1 or 2 carbon atoms, and most preferably a methylene group.
• Ar P3 is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms.
• the aryl group may have a substituent, and preferably has one or more substituents.
• substituents examples include an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and a combination thereof.
• a phenyl group a naphthyl group, a p-tolyl group, a p-ethylphenyl group, a p-t-butylphenyl group, a p-chlorophenyl group, a p-fluorophenyl group, a p-methoxyphenyl group, a p-dimethylaminophenyl group, a p-methylthiophenyl group, a p-phenylthiophenyl group, a p-phenylphenyl group, an o-tolyl group, an o-ethylphenyl group, an o-tBuphenyl group, an o-chlorophenyl group, an o-fluorophenyl group, an o-methoxyphenyl group, an o-dimethylaminophenyl group, an o-methylthiophenyl group, and an o
• Ar P3 is preferably an aryl group having one or more substituents on the aromatic ring, more preferably a phenyl group having one or more substituents on the aromatic ring (substituted phenyl group), further preferably an alkylphenyl group, particularly preferably a phenyl group having a branched alkyl group, and most preferably a t-butylphenyl group.
• the alkylphenyl group is preferably a p-alkylphenyl group.
• R P11 to R P14 and R P17 to R P20 each represent a hydrogen atom, an alkyl group, an aryl group, a hydroxyl group, an alkoxy group, or a halogen atom, and may be the same or different groups. Furthermore, a plurality of R P11 to R P14 and R P17 to R P20 may be linked together to form a ring.
• the alkyl groups represented by R P11 to R P14 and R P17 to R P20 may be linear, branched, or have a cyclic structure.
• Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, an isopropyl group, an isobutyl group, a s-butyl group, a t-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl group
• the alkyl groups in R P11 to R P14 and R P17 to R P20 may have a substituent.
• substituents include an aryl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and combinations thereof.
• the aryl group for R P11 to R P14 and R P17 to R P20 is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms.
• the aryl group may have a substituent.
• substituents examples include an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and combinations thereof.
• aryl groups a phenyl group, a p-methoxyphenyl group, a p-dimethylaminophenyl group, or a naphthyl group is preferred.
• R P11 to R P14 and R P17 to R P20 are each preferably independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and particularly preferably a hydrogen atom.
• R P15 and R P16 represent a hydrogen atom, an alkyl group, or an aryl group, and may be the same group or different groups. From the viewpoints of visibility, printing durability, and synthesis suitability, R P15 is preferably a hydrogen atom. From the viewpoints of visibility and printing durability, R P16 is preferably an alkyl group or an aryl group, more preferably an alkyl group, further preferably a branched alkyl group, and particularly preferably a t-butyl group.
• preferred examples of the branched alkyl group for R P16 include an isopropyl group, a t-butyl group, an isobutyl group, a cyclopentyl group, and a cyclohexyl group, and from the viewpoints of visibility and printing durability, preferred examples of the aryl group for R P16 include a phenyl group.
• the alkyl group for R P15 and R P16 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and even more preferably an alkyl group having 1 to 6 carbon atoms.
• the alkyl group for R P15 and R P16 may be linear, branched, or have a cyclic structure.
• Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, an isopropyl group, an isobutyl group, a s-butyl group, a t-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl group
• alkyl groups a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, an isobutyl group, a cyclopentyl group, or a cyclohexyl group is preferred.
• the alkyl group in R P15 and R P16 may have a substituent.
• substituents examples include an aryl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and combinations thereof.
• Preferred embodiments of the aryl group in R P15 and R P16 are the same as the preferred embodiments of the aryl group in R P11 to R P14 and R P17 to R P20 .
• Preferred embodiments of the alkyl groups in R P2 , R P3 , R P6 , R P7 , R P8 , R P9 and R P0 are the same as the preferred embodiments of the alkyl groups in R P11 to R P14 and R P17 to R P20 .
• Preferred embodiments of the aryl group in R P0 are the same as the preferred embodiments of the aryl group in R P11 to R P14 and R P17 to R P20 .
• R P2 and R P3 are linked to form a ring.
• the ring is preferably a 5-membered or 6-membered ring, and particularly preferably a 5-membered ring.
• Y P1 and Y P2 each independently represent an oxygen atom, a sulfur atom, -NR P0 - or a dialkylmethylene group, preferably -NR P0 - or a dialkylmethylene group, more preferably a dialkylmethylene group.
• R P0 represents a hydrogen atom, an alkyl group or an aryl group, and is preferably an alkyl group.
• the alkyl group in R P4 or R P5 is preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.
• the alkyl group in R P4 or R P5 may be linear, branched, or have a ring structure.
• Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, an isopropyl group, an isobutyl group, a s-butyl group, a t-butyl group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, a cyclohexyl group, a cyclopentyl group
• the alkyl group in R P4 or R P5 may have a substituent.
• substituents include an aryl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, and combinations thereof.
• alkyl groups for R P4 or R P5 a methyl group, an ethyl group, a propyl group, or a butyl group is preferred.
• the substituent on the alkyl group is preferably a methoxy group, a phenoxy group, a phenyl group or a naphthyl group.
• the alkyl group for R P4 or R P5 is particularly preferably an ethyl group or a propyl group having a substituent (for example, the substituent of Dye-12 described below).
• R P4 and R P5 are preferably the same group.
• R P6 to R P9 each independently represent a hydrogen atom or an alkyl group, and preferably a hydrogen atom.
• Ar P1 and Ar P2 each independently represent a group forming a benzene ring or a naphthalene ring.
• the benzene ring and the naphthalene ring may have a substituent.
• the substituent include an alkyl group, an alkoxy group, an aryloxy group, an amino group, an alkylthio group, an arylthio group, a halogen atom, a carboxy group, a carboxylate group, a sulfo group, a sulfonate group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a phosphonic acid group, and a group formed by combining these groups.
• the substituent is preferably an alkyl group or an alkoxy group.
• Ar P1 and Ar P2 are each preferably a group forming a naphthalene ring or a benzene ring having an alkyl group or an alkoxy group as a substituent, more preferably a group forming a naphthalene ring or a benzene ring having an alkoxy group as a substituent, and particularly preferably a group forming a benzene ring having a methoxy group as a substituent.
• Ar P1 or Ar P2 is preferably a group that forms a group represented by the following formula:
• R P21 each independently represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, an amino group, an alkoxythio group, or a halogen atom; nP3 represents an integer of 1 to 4; multiple R P21 may be bonded to each other to form a ring; and * represents a bonding site.
• Za represents a counter ion for neutralizing the charge.
• the counter ion may be one type of counter ion, two or more types of counter ions, or two or more counter ions of the same or different types.
• Za is not required.
• examples include sulfonate ion, carboxylate ion, tetrafluoroborate ion, hexafluorophosphate ion, p-toluenesulfonate ion, perchlorate ion, etc., with tetrafluoroborate ion, hexafluorophosphate ion, and p-toluenesulfonate ion being preferred.
• examples include alkali metal ion, alkaline earth metal ion, ammonium ion, pyridinium ion, sulfonium ion, etc., with sodium ion, potassium ion, ammonium ion, pyridinium ion, and sulfonium ion being preferred, with sodium ion, potassium ion, and ammonium ion being more preferred.
• R P2 to R P9 , R P0 , Ar P1 , Ar P2 , Y P1 and Y P2 may have an anionic structure or a cationic structure.
• Za has two monovalent counter anions or is a divalent counter anion.
• Za can also be a counter cation.
• the compound represented by the above formula (P1) is preferably a compound represented by the following formula (P5) or formula (P6), more preferably a compound represented by the following formula (P7) or formula (P8), and particularly preferably a compound represented by the following formula (P9).
• R P4 and R P5 each independently represent an alkyl group
• R P10 represents a monovalent organic group having an aryl group
• R P11 to R P14 and R P17 to R P20 each independently represent a hydrogen atom, an alkyl group, an aryl group, a hydroxy group, an alkoxy group, or a halogen atom
• R P15 and R P16 each independently represent a hydrogen atom, an alkyl group, or an aryl group
• at least two of R P11 to R P20 may be bonded to form a ring structure
• R P21 each independently represent an alkyl group, alkoxy group, aryloxy group, amino group, alkoxythio group, or halogen atom having 1 to 12 carbon atoms
• Za represents a counter ion that neutralizes the charge.
• X P2 represents a single bond or an alkylene group
• Ar P3 represents an aryl group
• R 4 and R 5 each independently represent an alkyl group
• R P15 and R P16 each independently represent a hydrogen atom, an alkyl group or an aryl group
• R P15 and R P16 may be bonded to form a ring structure
• R P21 each independently represent an alkyl group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, an amino group, an alkoxythio group or a halogen atom
• Za represents a counter ion that neutralizes the charge.
• Ar P4 represents an aryl group
• R P4 and R P5 each independently represent an alkyl group
• R P21 each independently represent an alkyl group having 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, an amino group, an alkoxythio group, or a halogen atom
• R P22 represents a hydrogen atom, an alkyl group, or an aryl group
• R P23 each independently represent a hydrogen atom or an alkyl group
• Za represents a counter ion that neutralizes the charge.
• R P4 , R P5 , R P11 to R P20 and Za in formulae (P5) to (P9) are the same as the preferred embodiments of R P4 , R P5 , R P11 to R P20 and Za in formulae (P1) to (P3), respectively.
• Preferred embodiments of R P21 in formulae (P5) to (P9) are the same as the preferred embodiments of R P21 described above.
• Preferred embodiments of X P2 and Ar P3 in formula (P7) and formula (P8) are the same as the preferred embodiments of X P2 and Ar P3 in formula (P4).
• Ar 4 P4 is preferably an aryl group having 6 to 30 carbon atoms, more preferably an aryl group having 6 to 20 carbon atoms, and even more preferably an aryl group having 6 to 12 carbon atoms.
• the aryl group may have a substituent, for example, an alkyl group, an alkoxy group, an aryloxy group, or a combination thereof. Among these, the substituent is preferably an alkyl group.
• Ar P4 in formula (P9) include a phenyl group, a naphthyl group, a p-tolyl group, a p-ethylphenyl group, a p-t-butylphenyl group, a p-fluorophenyl group, and a p-methoxyphenyl group.
• Ar P4 is preferably a phenyl group, a p-methoxyphenyl group, a p-tBuphenyl group, or a naphthyl group, more preferably a phenyl group, a p-methoxyphenyl group, or a p-t-butylphenyl group, and particularly preferably a p-t-butylphenyl group.
• R P22 in formula (P9) is preferably an alkyl group, more preferably an alkyl group having 1 to 8 carbon atoms, which may be interrupted by an oxygen atom or the like.
• the alkyl group preferably has 1 to 6 carbon atoms, more preferably 3 to 5 carbon atoms, and particularly preferably 3 or 4 carbon atoms, from the viewpoints of visibility, printing durability, and synthesis suitability.
• R P23 in formula (P9) is preferably a hydrogen atom.
• infrared absorbent that decomposes upon exposure to infrared rays
• those described in JP-T-2008-544322 or WO 2016/027886 can be suitably used.
• cyanine dye which is a decomposable infrared absorber the infrared absorbing compounds described in WO 2019/219560 can be suitably used.
• the infrared absorbing agent may be used alone or in combination of two or more.
• the image recording layer preferably contains two or more infrared absorbing agents. By using two or more infrared absorbing agents in combination, the suppression of development failure over time and the printing durability are further improved.
• a pigment and a dye may be used in combination as the infrared absorbing agent.
• the total content of the infrared absorbing agent in the image recording layer is preferably from 0.1% by mass to 10.0% by mass, and more preferably from 0.5% by mass to 5.0% by mass, based on the total mass of the image recording layer.
• the image recording layer in the present disclosure contains a specific borate compound and an electron-accepting polymerization initiator, and preferably further contains an infrared absorbing agent.
• the image recording layer contains a specific borate compound, an electron-accepting polymerization initiator, and an infrared absorbing agent, it is preferred that the HOMO of the specific borate compound is ⁇ 6.0 eV or more and the LUMO of the electron-accepting polymerization initiator is ⁇ 3.0 eV or less.
• More preferred embodiments of the HOMO of the specific borate compound and the LUMO of the electron-accepting polymerization initiator are as described above.
• the specific borate compound, at least one type of infrared absorbing agent, and the electron-accepting polymerization initiator transfer energy, for example, as shown in the following chemical formula. Therefore, if the HOMO of the specific borate compound is ⁇ 6.0 eV or more and the LUMO of the electron-accepting polymerization initiator is ⁇ 3.0 eV or less, it is considered that the radical generation efficiency is improved, and therefore the chemical resistance and printing durability are more likely to be excellent.
• the HOMO value of at least one HOMO-specific borate compound of the infrared absorber is preferably 1.0 eV or less, more preferably 0.70 eV or less, and particularly preferably 0.60 eV or less.
• the HOMO value of at least one HOMO-specific borate compound of the infrared absorber is preferably -0.200 eV or more, more preferably -0.100 eV or more.
• a negative value means that the HOMO of the specific borate compound is higher than the HOMO of at least one of the infrared absorbents.
• the LUMO value of at least one of the LUMO of the electron-accepting polymerization initiator-infrared absorber is preferably 1.00 eV or less, and more preferably 0.700 eV or less. From the same viewpoint, the LUMO value of at least one of the LUMO of the electron-accepting polymerization initiator and the LUMO of the infrared absorber is preferably ⁇ 0.200 eV or more, and more preferably ⁇ 0.100 eV or more.
• the value of LUMO of the electron-accepting polymerization initiator minus LUMO of at least one of the infrared absorbers is preferably 1.00 eV to -0.200 eV, more preferably 0.700 eV to -0.100 eV.
• a negative value means that the LUMO of at least one of the infrared absorbers is higher than the LUMO of the electron-accepting polymerization initiator.
• the image recording layer preferably contains a color former, and more preferably contains an acid color former.
• color former as used in the present disclosure means a compound having a property of developing or decoloring in response to a stimulus such as light or acid, thereby changing the color of the image recording layer
• acid color former means a compound having a property of developing or decoloring in response to heating in a state in which an electron-accepting compound (e.g., a proton such as an acid) is accepted, thereby changing the color of the image recording layer.
• a colorless compound having a partial skeleton such as lactone, lactam, sultone, spiropyran, ester, amide, or the like, which rapidly opens or cleaves the partial skeleton when it comes into contact with an electron-accepting compound, is preferred.
• acid color formers examples include 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (also called “crystal violet lactone"), 3,3-bis(4-dimethylaminophenyl)phthalide, 3-(4-dimethylaminophenyl)-3-(4-diethylamino-2-methylphenyl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(2-methylphenyl)phthalide, 3,3-bis(1,2-dimethylindol-3-yl)-phthalide, 3,3-bis(1,2-dimethylindol-3-yl)-5-dimethylaminophthalide, 3,3-bis(1,2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3,3
• the color former used in the present disclosure is preferably at least one compound selected from the group consisting of spiropyran compounds, spirooxazine compounds, spirolactone compounds, and spirolactam compounds.
• the hue of the dye after color development is preferably green, blue or black.
• the acid color former is preferably a leuco dye from the viewpoints of color development and visibility of exposed areas.
• the leuco dye is not particularly limited as long as it has a leuco structure, but it preferably has a spiro structure, and more preferably has a spirolactone ring structure. From the viewpoints of color development and visibility of exposed areas, the leuco dye is preferably a leuco dye having a phthalide structure or a fluoran structure.
• the leuco dye having a phthalide structure or a fluoran structure is preferably a compound represented by any one of the following formulas (Le-1) to (Le-3), and more preferably a compound represented by the following formula (Le-2).
• ERG each independently represents an electron donating group
• X 1 to X 4 each independently represent a hydrogen atom, a halogen atom, or a dialkylanilino group
• X 5 to X 10 each independently represent a hydrogen atom, a halogen atom, or a monovalent organic group
• Y 1 and Y 2 each independently represent C or N, and when Y 1 is N, X 1 is not present, and when Y 2 is N, X 4 is not present
• Ra 1 represents a hydrogen atom, an alkyl group, or an alkoxy group
• Rb 1 to Rb 4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group.
• an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group is preferable, an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroaryla
• the electron-donating group in the above ERG is preferably a di-substituted amino group having an aryl group having a substituent at at least one ortho position or a heteroaryl group having a substituent at at least one ortho position, more preferably a di-substituted amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position, still more preferably an amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position, and an aryl group or a heteroaryl group, and particularly preferably an amino group having a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position, and an aryl group having an electron-donating group or a heteroaryl group having an electron-donating group.
• the ortho position in an aryl group or heteroaryl group other than a phenyl group refers to the bonding position adjacent to the bonding position 1 (e.g., the 2nd position, etc.) when the bonding position of the aryl group or heteroaryl group to another structure is defined as the 1st position.
• the electron-donating group contained in the aryl group or heteroaryl group is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, more preferably an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, and particularly preferably an alkoxy group.
• X 1 to X 4 each independently represent, from the viewpoints of color development and visibility of exposed areas, preferably a hydrogen atom or a chlorine atom, and more preferably a hydrogen atom.
• X 5 to X 10 are each independently, from the viewpoint of color development and visibility of the exposed area, preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, a hydroxy group, an alkoxy group, an aryloxy group, a heteroaryloxy group
• Ra 1 in formulae (Le-1) to (Le-3) is preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and particularly preferably a methoxy group.
• Rb 1 to Rb 4 each independently represent, from the viewpoints of color development and visibility of exposed areas, preferably a hydrogen atom or an alkyl group, more preferably an alkyl group, and particularly preferably a methyl group.
• the leuco dye having the above-mentioned phthalide structure or fluoran structure is more preferably a compound represented by any one of the following formulas (Le-4) to (Le-6), and even more preferably a compound represented by the following formula (Le-5).
• ERG each independently represents an electron donating group
• X 1 to X 4 each independently represent a hydrogen atom, a halogen atom, or a dialkylanilino group
• Y 1 and Y 2 each independently represent C or N, and when Y 1 is N, X 1 is not present, and when Y 2 is N, X 4 is not present
• Ra 1 represents a hydrogen atom, an alkyl group, or an alkoxy group
• Rb 1 to Rb 4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group.
• ERG, X 1 to X 4 , Y 1 , Y 2 , Ra 1 , and Rb 1 to Rb 4 in formulas (Le-4) to (Le-6) have the same meanings as ERG, X 1 to X 4 , Y 1 , Y 2 , Ra 1 , and Rb 1 to Rb 4 in formulas (Le-1) to (Le-3), respectively, and preferred embodiments are also the same.
• the leuco dye having the above-mentioned phthalide structure or fluoran structure is more preferably a compound represented by any one of the following formulas (Le-7) to (Le-9), and is particularly preferably a compound represented by the following formula (Le-8).
• X 1 to X 4 each independently represent a hydrogen atom, a halogen atom, or a dialkylanilino group
• Y 1 and Y 2 each independently represent C or N; when Y 1 is N, X 1 is not present; when Y 2 is N, X 4 is not present
• Ra 1 to Ra 4 each independently represent a hydrogen atom, an alkyl group, or an alkoxy group
• Rb 1 to Rb 4 each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group
• Rc 1 and Rc 2 each independently represent an aryl group or a heteroaryl group.
• X 1 to X 4 , Y 1 and Y 2 in formulae (Le-7) to (Le-9) have the same meanings as X 1 to X 4 , Y 1 and Y 2 in formulae (Le-1) to (Le-3), and preferred embodiments are also the same.
• Ra 1 to Ra 4 are each independently preferably an alkyl group or an alkoxy group, more preferably an alkoxy group, and particularly preferably a methoxy group, from the viewpoints of color development and visibility of the exposed area.
• Rb 1 to Rb 4 are each independently, from the viewpoints of color development and visibility of the exposed area, preferably a hydrogen atom, an alkyl group, or an aryl group substituted with an alkoxy group, more preferably an alkyl group, and particularly preferably a methyl group.
• Rc 1 and Rc 2 each independently represent, from the viewpoints of color development and visibility of exposed areas, preferably a phenyl group or an alkylphenyl group, and more preferably a phenyl group.
• Rc 1 and Rc 2 in formula (Le-8) are each independently preferably an aryl group having a substituent at at least one ortho position, or a heteroaryl group having a substituent at at least one ortho position, more preferably an aryl group having a substituent at at least one ortho position, even more preferably a phenyl group having a substituent at at least one ortho position, and particularly preferably a phenyl group having a substituent at at least one ortho position and an electron-donating group at the para position.
• substituents in Rc 1 and Rc 2 include the substituents described below.
• X 1 to X 4 are hydrogen atoms
• Y 1 and Y 2 are C.
• Rb1 and Rb2 each independently represent an aryl group substituted with an alkyl group or an alkoxy group.
• Rb1 and Rb2 are each preferably independently an aryl group or a heteroaryl group, more preferably an aryl group, still more preferably an aryl group having an electron-donating group, and particularly preferably a phenyl group having an electron-donating group at the para position.
• the electron-donating group in Rb1 , Rb2 , Rc1 , and Rc2 is preferably an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, more preferably an alkoxy group, an aryloxy group, a heteroaryloxy group, or an alkyl group, and particularly preferably an alkoxy group.
• the acid color former contains one or more compounds selected from the group consisting of compounds represented by the following formula (Le-10) and compounds represented by the following formula (Z-4):
• the image recording layer in the lithographic printing plate precursor according to the present disclosure further contains one or more compounds selected from the group consisting of compounds represented by the following formula (Le-10) and compounds represented by the following formula (Z-4):
• Ar 1 's each independently represent an aryl group or a heteroaryl group
• Ar 2 's each independently represent an aryl group having a substituent at at least one ortho-position, or a heteroaryl group having a substituent at at least one ortho-position.
• Ar 1 in formula (Le-10) has the same meaning as Rb 1 and Rb 2 in formulas (Le-7) to (Le-9), and preferred embodiments are also the same.
• Ar 2 in formula (Le-10) has the same meaning as Rc 1 and Rc 2 in formulas (Le-7) to (Le-9), and preferred embodiments are also the same.
• the alkyl group in the formulae (Le-1) to (Le-9) may be linear, branched, or have a ring structure.
• the number of carbon atoms in the alkyl group in formulas (Le-1) to (Le-9) is preferably 1 to 20, more preferably 1 to 8, even more preferably 1 to 4, and particularly preferably 1 or 2.
• the aryl group in formulae (Le-1) to (Le-10) preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms, and particularly preferably 6 to 8 carbon atoms.
• aryl group in formulae (Le-1) to (Le-10) include a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthrenyl group, each of which may have a substituent.
• heteroaryl group in formulae (Le-1) to (Le-10) include a furyl group, a pyridyl group, a pyrimidyl group, a pyrazoyl group, and a thiophenyl group, each of which may have a substituent.
• each of the monovalent organic groups, alkyl groups, aryl groups, heteroaryl groups, dialkylanilino groups, alkylamino groups, alkoxy groups, etc. in formulas (Le-1) to (Le-10) may have a substituent.
• substituents examples include an alkyl group, an aryl group, a heteroaryl group, a halogen atom, an amino group, an alkylamino group, an arylamino group, a heteroarylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a monoalkylmonoheteroarylamino group, a diarylamino group, a diheteroarylamino group, a monoarylmonoheteroarylamino group, a hydroxy group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a heteroaryloxycarbonyl group, a cyano group, etc. In addition, these substituents may be further substituted with these substituents.
• Rza 1 represents a hydrogen atom, an alkyl group or an alkoxy group
• Rzb 1 to Rb 4 each independently represent a hydrogen atom, an alkyl group or an aryl group
• Rzb 1 and Rzb 2 , and Rzb 3 and Rzb 4 may be linked to form a ring structure
• X represents O or NR
• R represents a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group
• Y 1 and Y 2 each independently represent CH or N.
• Rza 1 is preferably an alkyl group or an alkoxy group. It is preferable that Rzb1 and Rzb2 in formula (Z-4) each independently represent an alkyl group. In formula (Z-4), Rzb3 and Rzb4 each independently represent a hydrogen atom, an alkyl group, or an aryl group, and it is preferable that one of them is an aryl group. In formula (Z-4), it is preferred that X is O, and Y 1 and Y 2 are CH.
• the alkyl group in formula (Z-4) may be linear, branched, or have a ring structure.
• the alkyl group in formula (Z-4) preferably has 1 to 20 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms.
• the aryl group in formula (Z-4) preferably has 6 to 20 carbon atoms, more preferably 6 to 10 carbon atoms, and particularly preferably 6 to 8 carbon atoms.
• Each group in formula (Z-4), such as an alkyl group or an aryl group may have a substituent.
• substituents examples include an alkyl group, an aryl group, a halogen atom, an amino group, an alkylamino group, an arylamino group, a dialkylamino group, a monoalkylmonoarylamino group, a diarylamino group, a hydroxy group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a cyano group. These substituents may be further substituted with other substituents.
• colorants such as ETAC, RED500, RED520, CVL, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, BLUE220, H-3035, BLUE203, ATP, H-1046, H-2114 (all manufactured by Fukui Yamada Chemical Industry Co., Ltd.), ORANGE-DCF, Vermili Examples of the dye include on-DCF, PINK-DCF, RED-DCF, BLMB, CVL, GREEN-DCF, and TH-107 (manufactured by Hodogaya Chemical Co., Ltd.), ODB, ODB-2, ODB-4, ODB-250, ODB-BlackXV, Blue-63, Blue-502, GN-169, GN-2, Green-118, Red-40, and Red-8 (manufactured by Yamamoto Chemical Industry Co., Ltd.), and crystal violet lactone (manufactured by Tokyo Chemical Industry
• ETAC, S-205, BLACK305, BLACK400, BLACK100, BLACK500, H-7001, GREEN300, NIRBLACK78, H-3035, ATP, H-1046, H-2114, GREEN-DCF, Blue-63, GN-169, and crystal violet lactone are preferred because the films they form have good visible light absorptance.
• color formers may be used alone or in combination of two or more kinds.
• the content of the color former is preferably from 0.5% by mass to 10% by mass, and more preferably from 1% by mass to 5% by mass, based on the total mass of the image recording layer.
• the image recording layer also preferably contains a polymerizable compound.
• a polymerizable compound refers to a compound having a polymerizable group.
• the polymerizable group is not particularly limited and may be any known polymerizable group, but is preferably an ethylenically unsaturated group.
• the polymerizable group may be either a radically polymerizable group or a cationic polymerizable group, but is preferably a radically polymerizable group.
• Examples of the radically polymerizable group include a (meth)acryloyl group, an allyl group, a vinylphenyl group, and a vinyl group, and from the viewpoint of reactivity, a (meth)acryloyl group is preferred.
• the molecular weight of the polymerizable compound (when the polymerizable compound has a molecular weight distribution, the weight average molecular weight) is preferably 50 or more and less than 2,500.
• the polymerizable compound may be, for example, a radically polymerizable compound or a cationic polymerizable compound, but is preferably an addition-polymerizable compound having at least one ethylenically unsaturated bond (ethylenically unsaturated compound).
• the ethylenically unsaturated compound is preferably a compound having at least one terminal ethylenically unsaturated bond, more preferably a compound having two or more terminal ethylenically unsaturated bonds.
• the polymerizable compound has a chemical form such as a monomer, a prepolymer, i.e., a dimer, a trimer or an oligomer, or a mixture thereof.
• the polymerizable compound preferably contains a trifunctional or more polymerizable compound, more preferably contains a heptafunctional or more polymerizable compound, and even more preferably contains a ten-functional or more polymerizable compound.
• the polymerizable compound preferably contains a trifunctional or more (preferably heptafunctional or more, more preferably ten-functional or more) ethylenically unsaturated compound, and even more preferably contains a trifunctional or more (preferably heptafunctional or more, more preferably ten-functional or more) (meth)acrylate compound.
• the polymerizable compound preferably contains a polymerizable compound having two or fewer functionalities, more preferably contains a bifunctional polymerizable compound, and particularly preferably contains a bifunctional (meth)acrylate compound.
• the content of the difunctional or lower polymerizable compound is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, and particularly preferably 15% by mass to 100% by mass, relative to the total mass of the polymerizable compounds in the image recording layer.
• polymer BB has a structural unit (Bb1) represented by the following formula (BI).
• R and R each independently represent a hydrogen atom or an alkyl group
• R represents a hydrogen atom or a monovalent substituent
• L and L each independently represent a single bond or a divalent linking group
• Rh represents a substituent containing two or more silicon atoms.
• Examples of the alkyl group represented by R B11 and R B12 include linear alkyl groups having 1 to 18 carbon atoms, and branched or cyclic alkyl groups having 3 to 18 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, and a cyclohexyl group. Both R B11 and R B12 are preferably a hydrogen atom.
• Examples of the monovalent substituent represented by R include an alkyl group, an alkenyl group, and an aryl group.
• the alkyl group, the alkenyl group, and the aryl group are the same as the alkyl group, the alkenyl group, and the aryl group represented by R 1 , R 2 , and R 3 , respectively, and the preferred embodiments are also the same.
• R6 is preferably a hydrogen atom or a methyl group.
• the divalent linking group represented by L B11 is preferably an ester bond, --C(.dbd.O)--O--.
• the divalent linking group represented by L B12 is not particularly limited as long as it is a group capable of linking L B11 and Rh.
• Examples of the divalent linking group represented by L B12 include an alkylene group.
• the alkylene group is preferably an alkylene group having 2 to 10 carbon atoms, and more preferably an alkylene group having 4 to 8 carbon atoms.
• the substituent containing two or more silicon atoms represented by Rh is not particularly limited as long as the atomic group constituting the substituent contains two or more silicon atoms.
• the substituent containing two or more silicon atoms preferably contains the silicon atoms as silicon-oxygen bonds (Si-O bonds).
• the substituent containing two or more silicon atoms preferably has two or more silicon-oxygen bonds, preferably three or more, and preferably 3 to 12.
• the substituent containing two or more silicon atoms preferably contains the silicon-oxygen bonds as a polysiloxane structure.
• the substituent containing two or more silicon atoms preferably has a branched structure, and more preferably has a branched structure branched from the silicon atom at the center.
• a substituent containing two or more silicon atoms specifically, a group containing two or more structures represented by the following formula (BIa) is preferable.
• R b11 , R b12 , and R b13 each independently represent an alkyl group, an alkenyl group, an aryl group, or an alkylenearyl group.
• Examples of the alkyl group represented by R b11 , R b12 , and R b13 include linear alkyl groups having 1 to 18 carbon atoms, and branched or cyclic alkyl groups having 3 to 18 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, and a cyclohexyl group. Examples of the alkenyl group represented by R b11 , R b12 , and R b13 include alkenyl groups having 2 to 12 carbon atoms.
• alkenyl group examples include a vinyl group, a 1-propenyl group, a 1-butenyl group, a 1-methyl-1-propenyl group, a 1-cyclopentenyl group, and a 1-cyclohexenyl group.
• aryl group represented by R b11 , R b12 , and R b13 examples include aryl groups having a carbon number of 6 to 12.
• Specific examples of the aryl group include a phenyl group, an ⁇ -methylphenyl group, and a naphthyl group.
• alkylenearyl group represented by R b11 , R b12 , and R b13 examples include alkylenearyl groups having 7 to 30 carbon atoms.
• R b11 , R b12 , and R b13 each independently represent an alkyl group, more preferably all represent the same alkyl group, further preferably all represent an alkyl group having 1 to 4 carbon atoms, and particularly preferably all represent a methyl group.
• the substituent containing two or more silicon atoms is preferably a group containing three or more structures represented by the above formula (BIa), and more preferably a group containing three to six silicon atoms.
• the substituent containing two or more silicon atoms is preferably a group represented by the following formula (Ba2).
• R b1 , R b2 , and R b3 each independently represent an alkyl group, an alkenyl group, an aryl group, or an alkylenearyl group.
• alkyl group represented by R b1 , R b2 , and R b3 include linear alkyl groups having 1 to 18 carbon atoms, and branched or cyclic alkyl groups having 3 to 18 carbon atoms.
• alkyl group examples include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, and a cyclohexyl group.
• alkenyl group represented by R b1 , R b2 , and R b3 examples include alkenyl groups having 2 to 12 carbon atoms.
• alkenyl group include a vinyl group, a 1-propenyl group, a 1-butenyl group, a 1-methyl-1-propenyl group, a 1-cyclopentenyl group, and a 1-cyclohexenyl group.
• Examples of the aryl group represented by R b1 , R b2 , and R b3 include aryl groups having a carbon number of 6 to 12. Specific examples of the aryl group include a phenyl group, an ⁇ -methylphenyl group, and a naphthyl group. Examples of the alkylenearyl group represented by R b1 , R b2 , and R b3 include alkylenearyl groups having 7 to 30 carbon atoms.
• R b1 , R b2 , and R b3 each independently represent an alkyl group, it is more preferable that all of them represent the same alkyl group, it is further preferable that all of them represent an alkyl group having 1 to 4 carbon atoms, and it is particularly preferable that all of them represent a methyl group.
• n is an integer from 2 to 1000.
• the polymerizable BB is preferably a copolymer containing a structural unit having a substituent containing two or more silicon atoms in the side chain and a structural unit having a hydrophilic group in the side chain.
• the structural unit having a hydrophilic group on the side chain contained in the polymerizable BB is preferably a structural unit represented by the following formula (a4).
• R and R each independently represent a hydrogen atom or an alkyl group
• R represents a hydrogen atom or a monovalent substituent
• L and L represent a single bond or a divalent linking group
• X represents a hydrophilic group
• R 4 and R 5 each independently represent a hydrogen atom or an alkyl group.
• the alkyl group represented by R and R include linear alkyl groups having 1 to 18 carbon atoms, and branched or cyclic alkyl groups having 3 to 18 carbon atoms.
• Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, and a cyclohexyl group.
• Both R B7 and R B8 are preferably a hydrogen atom.
• Examples of the monovalent substituent represented by R include an alkyl group, an alkenyl group, and an aryl group.
• the alkyl group, the alkenyl group, and the aryl group are the same as the alkyl group , the alkenyl group, and the aryl group represented by R, R , and R , respectively, and the preferred embodiments are also the same.
• R B9 is preferably a hydrogen atom or a methyl group.
• the divalent linking group represented by L B3 is not particularly limited as long as it is a group capable of linking L B2 and X B.
• Examples of the divalent linking group represented by L B3 include an alkylene group.
• the alkylene group is preferably an alkylene group having 2 to 10 carbon atoms, and more preferably an alkylene group having 4 to 8 carbon atoms.
• Examples of the hydrophilic group represented by XB include a hydroxyl group, a phosphate group, a polyalkyleneoxy group, or a group combining two or more of these.
• examples of the polyalkyleneoxy group include a polyethyleneoxy group, a polypropyleneoxy group, a polybutyleneoxy group, or a group combining these.
• monomer units for forming a structural unit having a hydrophilic group on a side chain include monomers represented by H-1 to H-40. Specific examples of monomer units for forming a structural unit having a hydrophilic group on a side chain are not limited to these.
• n and m are each independently an integer from 2 to 100.
• random means that multiple types of polyalkyleneoxy groups are arranged randomly.
• the polymer BB may contain one type of structural unit having a substituent containing two or more silicon atoms in a side chain, or may contain two or more types of structural units.
• the content of the structural unit having a substituent containing two or more silicon atoms in a side chain, relative to the mass of polymer BB may be 100% by mass, is preferably 15% by mass to 70% by mass, is more preferably 20% by mass to 60% by mass, and is further preferably 25% by mass to 50% by mass.
• the polymer BB may contain one type of structural unit having a hydrophilic group on the side chain, or may contain two or more types of structural units.
• the content of the structural unit having a hydrophilic group in a side chain is preferably 30% by mass to 85% by mass, more preferably 40% by mass to 80% by mass, and even more preferably 50% by mass to 75% by mass, relative to the mass of the polymer BB.
• the polymer BB may further contain other structural units.
• Other structural units include, for example, structural units having a carboxylic acid group in the side chain.
• structural units having a carboxylic acid group in the side chain for example, (meth)acrylic acid, itaconic acid, itaconic acid derivatives, etc. are included. It is preferable that the structural unit having a carboxylic acid group in the side chain is included as a structural unit other than the structural unit having the hydrophilic group in the side chain described above.
• alkyl (meth)acrylates alkyl groups having 1 to 24 carbon atoms
• styrene derivatives maleic anhydride, maleimide anhydride, (meth)acrylonitrile, vinyl ether derivatives, and alkyl (meth)acrylamide derivatives.
• the content of the other structural units is preferably 0% by mass to 20% by mass relative to the mass of polymer BB.
• the weight average molecular weight of polymer BB is preferably 5,000 to 100,000, and more preferably 8,000 to 60,000, from the viewpoint of obtaining an image recording layer with excellent surface condition.
• polymer BB examples include BP-1 to BP-10 shown below. Specific examples of polymer BB are not limited to these.
• the content of polymer BB is preferably 0.001% by mass to 0.1% by mass, and more preferably 0.002% by mass to 0.01% by mass, based on the total mass of the image recording layer coating solution.
• the polymerizable compound contained in the image recording layer preferably contains a polymerizable compound which is an oligomer (hereinafter, also simply referred to as "oligomer").
• an oligomer refers to a polymerizable compound having a molecular weight (weight average molecular weight when the molecular weight has a molecular weight distribution) of 600 or more and 15,000 or less and containing at least one polymerizable group. From the viewpoint of excellent chemical resistance and printing durability, the molecular weight of the oligomer is preferably 1,000 or more and 15,000 or less.
• the number of polymerizable groups in one oligomer molecule is preferably 2 or more, more preferably 3 or more, even more preferably 6 or more, and particularly preferably 10 or more.
• the upper limit of the number of polymerizable groups in the oligomer is not particularly limited, but the number of polymerizable groups is preferably 20 or less.
• the oligomer preferably has 7 or more polymerizable groups and a molecular weight of 1,000 or more and 15,000 or less, and more preferably has 7 or more polymerizable groups and a molecular weight of 1,000 or more and 15,000 or less.
• the oligomer may contain a polymer component that may be generated during the production process of the oligomer.
• the oligomer preferably contains at least one selected from the group consisting of a compound having a urethane bond, a compound having an ester bond, and a compound having an epoxy residue, and more preferably contains a compound having a urethane bond.
• the epoxy residue refers to a structure formed by an epoxy group, and means, for example, a structure similar to the structure obtained by the reaction of an acid group (such as a carboxylic acid group) with an epoxy group.
• a compound having a urethane bond is preferably a compound having at least a group represented by the following formula (Ac-1) or formula (Ac-2), and more preferably a compound having at least a group represented by the following formula (Ac-1).
• L 1 to L 4 each independently represent a divalent hydrocarbon group having 2 to 20 carbon atoms, and the wavy line portion represents the bonding position to other structures.
• L 1 to L 4 are each independently preferably an alkylene group having 2 to 20 carbon atoms, more preferably an alkylene group having 2 to 10 carbon atoms, and even more preferably an alkylene group having 4 to 8 carbon atoms.
• the alkylene group may have a branched or cyclic structure, but is preferably a linear alkylene group.
• each of the wavy line portions in formula (Ac-1) or formula (Ac-2) is independently directly bonded to a wavy line portion in a group represented by formula (Ae-1) or formula (Ae-2) below.
• R each independently represents an acryloyloxy group or a methacryloyloxy group
• the wavy line portion represents the bonding position with the wavy line portion in formula (Ac-1) and formula (Ac-2).
• a compound in which a polymerizable group is introduced by a polymer reaction into a polyurethane obtained by reacting a polyisocyanate compound with a polyol compound may be used.
• a compound having a urethane bond may be obtained by reacting a polyurethane oligomer obtained by reacting a polyol compound having an acid group with a polyisocyanate compound, with a compound having an epoxy group and a polymerizable group.
• the number of polymerizable groups in a compound having an ester bond is preferably 3 or more, and more preferably 6 or more.
• a compound having an epoxy residue which is an example of an oligomer
• a compound containing a hydroxy group within the compound is preferred.
• the compound having an epoxy residue preferably has 2 to 6 polymerizable groups, and more preferably has 2 to 3 polymerizable groups.
• the compound having an epoxy residue can be obtained, for example, by reacting a compound having an epoxy group with acrylic acid.
• oligomers are shown in the table below, but the oligomers used in the present disclosure are not limited thereto.
• the oligomer commercially available products may be used, and examples thereof include UA510H, UA-306H, UA-306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.), UV-1700B, UV-6300B, UV7620EA (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), U-15HA (manufactured by Shin-Nakamura Chemical Co., Ltd.), EBECRYL450, EBECRYL657, EBECRYL885, EBECRYL800, EBECRYL3416, EBECRYL860 (all manufactured by Daicel Allnex Co., Ltd.), but are not limited thereto.
• the content of the oligomer is preferably 30% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, and even more preferably 80% by mass to 100% by mass, based on the total mass of the polymerizable compounds in the image recording layer.
• the polymerizable compound may further contain a polymerizable compound other than the above-mentioned oligomer.
• the polymerizable compound other than the oligomer is preferably a low molecular weight polymerizable compound.
• the low molecular weight polymerizable compound may be a monomer, a dimer, a trimer, or a combination thereof. It may be in any chemical form, such as a mixture.
• the low molecular weight polymerizable compound from the viewpoint of chemical resistance, at least one polymerizable compound selected from the group consisting of a polymerizable compound having three or more ethylenically unsaturated groups and a polymerizable compound having an isocyanuric ring structure is preferably used. It is preferable that the compound is a carboxylic acid compound.
• the low molecular weight polymerizable compound refers to a polymerizable compound having a molecular weight of 50 or more and less than 600 (weight average molecular weight when the compound has a molecular weight distribution).
• the molecular weight of the low molecular weight polymerizable compound is preferably 100 or more and less than 600, more preferably 300 or more and less than 600, and even more preferably 400 or more and less than 600.
• the ratio of the oligomer to the low molecular weight polymerizable compound is preferably 10/1 to 1/10 by mass, more preferably 10/1 to 3/7, and even more preferably 10/1 to 7/3.
• polymerizable compounds described in paragraphs 0082 to 0086 of WO 2019/013268 can also be suitably used as low molecular weight polymerizable compounds.
• the image recording layer contains two or more kinds of polymerizable compounds.
• the content of the polymerizable compounds is preferably 5% by mass to 75% by mass, more preferably 10% by mass to 70% by mass, and even more preferably 15% by mass to 60% by mass, based on the total mass of the image recording layer.
• the image recording layer also preferably contains particles.
• the particles may be organic particles or inorganic particles, but from the viewpoint of printing durability, it is preferable that the toner contains organic particles, and it is more preferable that the toner contains polymer particles.
• the inorganic particles known inorganic particles can be used, and metal oxide particles such as silica particles and titania particles can be suitably used.
• the polymer particles are preferably selected from the group consisting of thermoplastic resin particles, thermoreactive resin particles, polymer particles having a polymerizable group, microcapsules containing a hydrophobic compound, and microgels (e.g., crosslinked polymer particles). Among them, polymer particles or microgels having a polymerizable group are preferred. In a particularly preferred embodiment, the polymer particles contain at least one ethylenically unsaturated polymerizable group. The presence of such polymer particles provides the effect of increasing the printing durability of the exposed area and the on-press developability of the unexposed area. From the viewpoints of printing durability and on-press developability, the polymer particles are preferably thermoplastic resin particles.
• thermoplastic resin particles preferred are thermoplastic polymer particles described in Research Disclosure No. 33303 of January 1992, JP-A Nos. 9-123387, 9-131850, 9-171249, and 9-171250, and European Patent No. 931647, etc.
• Specific examples of the polymer constituting the thermoplastic resin particles include homopolymers or copolymers of monomers such as ethylene, styrene, vinyl chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinylidene chloride, acrylonitrile, vinylcarbazole, and acrylates or methacrylates having a polyalkylene structure, or mixtures thereof.
• Preferred examples include polystyrene, copolymers containing styrene and acrylonitrile, and polymethyl methacrylate.
• the average particle size of the thermoplastic resin particles is preferably 0.01 ⁇ m to 3.0 ⁇ m.
• Thermo-reactive resin particles include polymer particles that have thermo-reactive groups.
• Thermo-reactive polymer particles form hydrophobic regions due to cross-linking caused by the thermal reaction and the resulting changes in functional groups.
• the heat-reactive group in the polymer particle having a heat-reactive group may be any functional group that undergoes any reaction as long as a chemical bond is formed, but is preferably a polymerizable group, and examples of such groups include ethylenically unsaturated groups that undergo radical polymerization reactions (e.g., acryloyl groups, methacryloyl groups, vinyl groups, allyl groups, etc.), cationic polymerizable groups (e.g., vinyl groups, vinyloxy groups, epoxy groups, oxetanyl groups, etc.), isocyanato groups or their blocks that undergo addition reactions, epoxy groups, vinyloxy groups, and functional groups with active hydrogen atoms that are their reaction partners (e.g., amino groups, hydroxy groups, carboxy groups, etc.), carboxy groups and their reaction partners, hydroxy groups or amino groups that undergo condensation reactions, and acid anhydrides and their reaction partners, amino groups or hydroxy groups, that undergo ring-opening addition reactions.
• radical polymerization reactions e
• the microcapsules as described in, for example, JP-A Nos. 2001-277740 and 2001-277742, at least some of the components of the image recording layer are encapsulated in the microcapsules.
• the components of the image recording layer can also be contained outside the microcapsules.
• a preferred embodiment of the image recording layer containing microcapsules is one in which the hydrophobic components are encapsulated in the microcapsules and the hydrophilic components are contained outside the microcapsules.
• the microgel (e.g., crosslinked polymer particles) can contain some of the components of the image recording layer on at least one of its surface or interior.
• reactive microgels having radically polymerizable groups on their surface are preferred from the viewpoints of the sensitivity of the resulting lithographic printing plate precursor and the printing durability of the resulting lithographic printing plate.
• Known methods can be used to microencapsulate or microgel the components of the image recording layer.
• the polymer particles are preferably those obtained by reacting a polyisocyanate compound, which is an adduct of a polyhydric phenol compound having two or more hydroxy groups in the molecule with isophorone diisocyanate, with a compound having active hydrogen.
• the polyhydric phenol compound is preferably a compound having a plurality of benzene rings each having a phenolic hydroxy group.
• the compound having active hydrogen is preferably a polyol compound or a polyamine compound, more preferably a polyol compound, and even more preferably at least one compound selected from the group consisting of propylene glycol, glycerin, and trimethylolpropane.
• resin particles obtained by reacting a polyisocyanate compound, which is an adduct of a polyhydric phenol compound having two or more hydroxy groups in the molecule and isophorone diisocyanate, with a compound having active hydrogen include the polymer particles described in paragraphs 0032 to 0095 of JP2012-206495A.
• the polymer particles have a hydrophobic main chain and contain both i) a constituent unit having a pendant cyano group directly bonded to the hydrophobic main chain, and ii) a constituent unit having a pendant group that includes a hydrophilic polyalkylene oxide segment.
• a preferred example of the hydrophobic main chain is an acrylic resin chain.
• Preferred examples of the pendant cyano group include -[CH 2 CH(C ⁇ N)]- or -[CH 2 C(CH 3 )(C ⁇ N)]-.
• the structural unit having a pendant cyano group can be easily derived from an ethylenically unsaturated monomer, such as acrylonitrile or methacrylonitrile, or a combination thereof.
• the alkylene oxide in the hydrophilic polyalkylene oxide segment is preferably ethylene oxide or propylene oxide, and more preferably ethylene oxide.
• the number of repeating alkylene oxide structures in the hydrophilic polyalkylene oxide segment is preferably 10-100, more preferably 25-75, and even more preferably 40-50.
• Preferred examples of resin particles having a hydrophobic main chain and including both i) a constituent unit having a pendant cyano group directly bonded to the hydrophobic main chain, and ii) a constituent unit having a pendant group that includes a hydrophilic polyalkylene oxide segment include those described in paragraphs [0039] to [0068] of JP2008-503365A.
• the polymer particles preferably have a hydrophilic group.
• the hydrophilic group is not particularly limited as long as it has a structure having hydrophilicity, and examples of the hydrophilic group include acid groups such as a carboxy group, a hydroxy group, an amino group, a cyano group, and a polyalkylene oxide structure.
• acid groups such as a carboxy group, a hydroxy group, an amino group, a cyano group, and a polyalkylene oxide structure.
• a polyalkylene oxide structure is preferred, and a polyethylene oxide structure, a polypropylene oxide structure, or a polyethylene/propylene oxide structure is more preferred.
• the polyalkylene oxide structure preferably has a polypropylene oxide structure, and more preferably has a polyethylene oxide structure or a polypropylene oxide structure.
• the hydrophilic group preferably contains a structural unit having a cyano group or a group represented by the following formula Z, more preferably contains a structural unit represented by the following formula (AN) or a group represented by the following formula Z, and particularly preferably contains a group represented by the following formula Z: *-Q-W-Y Formula Z
• Q represents a divalent linking group
• W represents a divalent group having a hydrophilic structure or a divalent group having a hydrophobic structure
• Y represents a monovalent group having a hydrophilic structure or a monovalent group having a hydrophobic structure, either W or Y has a hydrophilic structure
• * represents a bonding site with
• R AN represents a hydrogen atom or a methyl group.
• the polymer contained in the polymer particles preferably contains a structural unit formed from a compound having a cyano group.
• the cyano group is preferably introduced into the resin as a structural unit containing a cyano group by using a compound (e.g., a monomer) having a cyano group.
• a compound having a cyano group include an acrylonitrile compound, and (meth)acrylonitrile is preferred.
• the structural unit having a cyano group is preferably a structural unit formed from an acrylonitrile compound, and more preferably a structural unit formed from (meth)acrylonitrile, that is, a structural unit represented by the above formula (AN).
• the content of the structural unit having a cyano group, preferably the structural unit represented by the above formula (AN), in the polymer having a structural unit having a cyano group is, from the viewpoint of printing durability, preferably 5% by mass to 90% by mass, more preferably 20% by mass to 80% by mass, and particularly preferably 30% by mass to 60% by mass, relative to the total mass of the polymer having a structural unit having a cyano group.
• the polymer particles contain polymer particles having a group represented by the above formula Z.
• Q in the above formula Z is preferably a divalent linking group having 1 to 20 carbon atoms, and more preferably a divalent linking group having 1 to 10 carbon atoms. Furthermore, Q in the above formula Z is preferably an alkylene group, an arylene group, an ester bond, an amide bond, or a group consisting of a combination of two or more of these, and more preferably a phenylene group, an ester bond, or an amide bond.
• the divalent group having a hydrophilic structure for W in the above formula Z is preferably a polyalkyleneoxy group or a group in which --CH 2 CH 2 NR W -- is bonded to one end of a polyalkyleneoxy group, where R W represents a hydrogen atom or an alkyl group.
• the divalent group having a hydrophobic structure in W of the above formula Z is preferably -R WA -, -O-R WA -O-, -R W N-R WA -NR W -, -OC( ⁇ O)-R WA -O-, or -OC( ⁇ O)-R WA -O-.
• Each R WA independently represents a linear, branched or cyclic alkylene group having 6 to 120 carbon atoms, a haloalkylene group having 6 to 120 carbon atoms, an arylene group having 6 to 120 carbon atoms, an alkylylene group having 6 to 120 carbon atoms (i.e., a divalent group obtained by removing one hydrogen atom from an alkylaryl group), or an aralkylene group having 6 to 120 carbon atoms.
• the polymer particles having a group represented by the above formula Z have W as a divalent group having a hydrophilic structure, Q as a phenylene group, an ester bond, or an amide bond, W as a polyalkyleneoxy group, and Y as a polyalkyleneoxy group whose terminal is a hydrogen atom or an alkyl group.
• the polymer particles preferably contain polymer particles having a polymerizable group, and more preferably contain polymer particles having a polymerizable group on the particle surface. Furthermore, from the viewpoint of printing durability, the polymer particles preferably contain polymer particles having a hydrophilic group and a polymerizable group.
• the polymerizable group may be a cationically polymerizable group or a radically polymerizable group, but from the viewpoint of reactivity, it is preferably a radically polymerizable group.
• the polymerizable group is not particularly limited as long as it is a polymerizable group, but from the viewpoint of reactivity, an ethylenically unsaturated group is preferred, a vinylphenyl group (styryl group), a (meth)acryloxy group, or a (meth)acrylamide group is more preferred, and a (meth)acryloxy group is particularly preferred.
• the polymer in the polymer particles having a polymerizable group preferably has a structural unit having a polymerizable group. Furthermore, polymerizable groups may be introduced onto the surfaces of the polymer particles by a polymer reaction.
• the image recording layer preferably contains, as the polymer particles, addition polymerization type resin particles having a dispersible group, and it is more preferable that the dispersible group contains a group represented by the formula Z.
• the above polymer particles preferably contain a resin having a urea bond, more preferably contain a resin having a structure obtained by at least reacting an isocyanate compound represented by the following formula (Iso) with water, and particularly preferably contain a resin having a structure obtained by at least reacting an isocyanate compound represented by the following formula (Iso) with water, and having a polyethylene oxide structure and a polypropylene oxide structure as the polyoxyalkylene structure.
• the particles containing the above resin having a urea bond are preferably microgels.
• n represents an integer from 0 to 10.
• a compound reactive with an isocyanate group e.g., a compound having active hydrogen
• an isocyanate group such as an alcohol compound or an amine compound
• a compound having active hydrogen include those described above in relation to the microgel.
• the resin having the urea bond preferably has an ethylenically unsaturated group, and more preferably has a group represented by the following formula (PETA).
• the image recording layer preferably contains thermoplastic resin particles.
• the thermoplastic resin contained in the thermoplastic resin particles is not particularly limited, and examples thereof include polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl (meth)acrylate, polyethyl (meth)acrylate, polybutyl (meth)acrylate, polyacrylonitrile, polyvinyl acetate, copolymers thereof, etc.
• the thermoplastic resin may be in a latex state.
• the thermoplastic resin according to the present disclosure is preferably a resin that forms all or part of the hydrophobic film that forms the recording layer by melting or softening the thermoplastic resin due to the heat generated in the exposure process described below.
• the thermoplastic resin contains a resin A having a structural unit formed from an aromatic vinyl compound and a structural unit having a cyano group.
• Resin A contained in the thermoplastic resin preferably has a structural unit formed from an aromatic vinyl compound.
• the aromatic vinyl compound may be any compound having a structure in which a vinyl group is bonded to an aromatic ring, and examples thereof include styrene compounds and vinylnaphthalene compounds, with styrene compounds being preferred, and styrene being more preferred.
• styrene compound examples include styrene, p-methylstyrene, p-methoxystyrene, ⁇ -methylstyrene, p-methyl- ⁇ -methylstyrene, ⁇ -methylstyrene, and p-methoxy- ⁇ -methylstyrene, with styrene being preferred.
• vinylnaphthalene compound examples include 1-vinylnaphthalene, methyl-1-vinylnaphthalene, ⁇ -methyl-1-vinylnaphthalene, 4-methyl-1-vinylnaphthalene, 4-methoxy-1-vinylnaphthalene, and the like, with 1-vinylnaphthalene being preferred.
• a structural unit formed by an aromatic vinyl compound a structural unit represented by the following formula A1 can be preferably mentioned.
• R A1 and R A2 each independently represent a hydrogen atom or an alkyl group
• Ar represents an aromatic ring group
• R A3 represents a substituent
• n represents an integer of 0 or more and the maximum number of substituents of Ar or less.
• R A1 and R A2 each independently preferably represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and further preferably both represent a hydrogen atom.
• Ar is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.
• R A3 is preferably an alkyl group or an alkoxy group, more preferably an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and further preferably a methyl group or a methoxy group.
• n is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.
• the content of structural units formed by aromatic vinyl compounds is preferably greater than the content of structural units having cyano groups, which will be described later, from the viewpoint of ink receptivity, and is more preferably 15% to 85% by mass, and even more preferably 30% to 70% by mass, relative to the total mass of the thermoplastic resin.
• Resin A contained in the thermoplastic resin particles preferably contains a structural unit having a cyano group.
• the cyano group is preferably introduced into the resin A as a structural unit containing a cyano group by using a compound (e.g., a monomer) having a cyano group.
• a compound e.g., a monomer
• the compound having a cyano group include acrylonitrile compounds, and (meth)acrylonitrile is preferred.
• the structural unit having a cyano group is preferably a structural unit formed from an acrylonitrile compound, and more preferably a structural unit formed from (meth)acrylonitrile.
• a preferred example of a structural unit formed by a compound having a cyano group is a structural unit represented by the following formula B1.
• R B1 represents a hydrogen atom or an alkyl group.
• R B1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.
• the content of structural units having a cyano group in resin A is preferably less than the content of structural units formed by the aromatic vinyl compound, and is more preferably 55% to 90% by mass, and even more preferably 60% to 85% by mass, relative to the total mass of resin A.
• the content ratio of the structural unit formed by the aromatic vinyl compound and the structural unit having a cyano group is preferably 5:5 to 9:1 by mass, and more preferably 6:4 to 8:2.
• the resin A contained in the thermoplastic resin particles further contains a structural unit formed from an N-vinyl heterocyclic compound.
• N-vinyl heterocyclic compound examples include N-vinylpyrrolidone, N-vinylcarbazole, N-vinylpyrrole, N-vinylphenothiazine, N-vinylsuccinimide, N-vinylphthalimide, N-vinylcaprolactam, and N-vinylimidazole, and N-vinylpyrrolidone is preferred.
• a preferred example of a structural unit formed by an N-vinyl heterocyclic compound is the structural unit represented by the following formula C1.
• Ar 4 N represents a heterocyclic structure containing a nitrogen atom, and the nitrogen atom in Ar 4 N is bonded to the carbon atom marked with *.
• the heterocyclic structure represented by Ar 2 N is preferably a pyrrolidone ring, a carbazole ring, a pyrrole ring, a phenothiazine ring, a succinimide ring, a phthalimide ring, a caprolactam ring, or an imidazole ring, and more preferably a pyrrolidone ring.
• the heterocyclic structure represented by Ar 2 N may have a known substituent.
• the content of structural units formed by N-vinyl heterocyclic compounds in Resin A is preferably 5% by mass to 50% by mass, and more preferably 10% by mass to 40% by mass, relative to the total mass of Resin A.
• Resin A contained in the thermoplastic resin particles may contain a structural unit having an acidic group. However, from the viewpoints of on-press developability and ink receptivity, it is preferable that the resin A does not contain a structural unit having an acidic group.
• the content of the structural unit having an acidic group in the thermoplastic resin is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less.
• the lower limit of the content is not particularly limited, and may be 0% by mass.
• the acid value of the thermoplastic resin is preferably 160 mgKOH/g or less, more preferably 80 mgKOH/g or less, and even more preferably 40 mgKOH/g or less.
• the lower limit of the acid value is not particularly limited, and may be 0 mgKOH/g.
• the acid value is determined by a measurement method in accordance with JIS K0070:1992.
• the resin A contained in the thermoplastic resin particles may contain a structural unit containing a hydrophobic group.
• the hydrophobic group include an alkyl group, an aryl group, and an aralkyl group.
• the structural unit containing a hydrophobic group a structural unit formed from an alkyl (meth)acrylate compound, an aryl (meth)acrylate compound, or an aralkyl (meth)acrylate compound is preferable, and a structural unit formed from an alkyl (meth)acrylate compound is more preferable.
• the number of carbon atoms in the alkyl group in the alkyl (meth)acrylate compound is preferably 1 to 10.
• the alkyl group may be linear or branched, or may have a cyclic structure.
• alkyl (meth)acrylate compound examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.
• the number of carbon atoms of the aryl group in the aryl(meth)acrylate compound is preferably 6 to 20, and more preferably a phenyl group.
• the aryl group may have a known substituent.
• a preferred example of the aryl(meth)acrylate compound is phenyl(meth)acrylate.
• the number of carbon atoms of the alkyl group in the aralkyl (meth)acrylate compound is preferably 1 to 10.
• the alkyl group may be linear or branched, and may have a cyclic structure.
• the number of carbon atoms of the aryl group in the aralkyl (meth)acrylate compound is preferably 6 to 20, and more preferably a phenyl group.
• a preferred example of the aralkyl (meth)acrylate compound is benzyl (meth)acrylate.
• the content of structural units having hydrophobic groups in resin A contained in the thermoplastic resin particles is preferably 5% by mass to 50% by mass, and more preferably 10% by mass to 30% by mass, relative to the total mass of resin A.
• the thermoplastic resin contained in the thermoplastic resin particles preferably has a hydrophilic group from the viewpoints of printing durability and on-press developability.
• the hydrophilic group is not particularly limited as long as it has a structure having hydrophilicity, and examples thereof include acid groups such as a carboxy group, a hydroxy group, an amino group, a cyano group, and a polyalkylene oxide structure.
• the hydrophilic group is preferably a group having a polyalkylene oxide structure, a group having a polyester structure, or a sulfonic acid group, more preferably a group having a polyalkylene oxide structure or a sulfonic acid group, and even more preferably a group having a polyalkylene oxide structure.
• the polyalkylene oxide structure is preferably a polyethylene oxide structure, a polypropylene oxide structure, or a poly(ethylene oxide/propylene oxide) structure.
• the hydrophilic group preferably has a polypropylene oxide structure as the polyalkylene oxide structure, and more preferably has a polyethylene oxide structure or a polypropylene oxide structure.
• the number of alkylene oxide structures in the polyalkylene oxide structure is preferably 2 or more, more preferably 5 or more, further preferably 5 to 200, and particularly preferably 8 to 150, from the viewpoint of on-press developability.
• the hydrophilic group is preferably a group represented by the above formula Z.
• the resin A contained in the thermoplastic resin particles contains a structural unit having a hydrophilic group.
• the hydrophilic group include -OH, -CN, -CONR 1 R 2 , -NR 2 COR 1 (R 1 and R 2 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group.
• R 1 and R 2 may be bonded to form a ring), -NR 3 R 4 , -N + R 3 R 4 R 5 X - (R 3 to R 5 each independently represent an alkyl group having 1 to 8 carbon atoms, and X - represents a counter anion), a group represented by the following formula PO, and hydrophilic groups preferably possessed by the thermoplastic resin contained in the above thermoplastic resin particles.
• hydrophilic groups --CONR 1 R 2 or a group represented by the formula PO is preferred, and a group represented by the formula PO is more preferred.
• each of L 1 P independently represents an alkylene group; R 1 P represents a hydrogen atom or an alkyl group; and n represents an integer of 1 to 100.
• each L 1 P is preferably an ethylene group, a 1-methylethylene group or a 2-methylethylene group, more preferably an ethylene group.
• R P is preferably a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, even more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.
• n is preferably an integer of 1 to 10, and more preferably an integer of 1 to 4.
• the content of structural units having hydrophilic groups in resin A is preferably 5% by mass to 60% by mass, and more preferably 10% by mass to 30% by mass, relative to the total mass of resin A.
• the resin A contained in the thermoplastic resin particles may further contain other structural units.
• the other structural units may contain structural units other than the above-mentioned structural units without any particular limitation, and examples thereof include structural units formed by an acrylamide compound, a vinyl ether compound, etc.
• Examples of the acrylamide compound include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, N,N'-dimethyl(meth)acrylamide, N,N'-diethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-hydroxypropyl(meth)acrylamide, and N-hydroxybutyl(meth)acrylamide.
• vinyl ether compounds include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, tert-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, 4-methylcyclohexylmethyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl vinyl
• the content of other structural units in the thermoplastic resin is preferably 5% to 50% by mass, and more preferably 10% to 30% by mass, relative to the total mass of the thermoplastic resin.
• the glass transition temperature (Tg) of the thermoplastic resin is preferably 60° C. to 150° C., more preferably 80° C. to 140° C., and even more preferably 90° C. to 130° C.
• the glass transition temperature of the thermoplastic resin is referred to as the glass transition temperature of the thermoplastic resin.
• the glass transition temperature of a resin can be measured using differential scanning calorimetry (DSC).
• DSC differential scanning calorimetry
• the specific measurement method is in accordance with the method described in JIS K 7121 (1987) or JIS K 6240 (2011).
• the glass transition temperature in this specification is the extrapolated glass transition onset temperature (hereinafter sometimes referred to as Tig).
• Tig extrapolated glass transition onset temperature
• the method for measuring the glass transition temperature will now be described more specifically.
• the temperature is maintained at about 50° C. lower than the expected Tg of the resin until the apparatus becomes stable, and then the temperature is heated at a heating rate of 20° C./min to a temperature about 30° C. higher than the temperature at which the glass transition ends, and a differential thermal analysis (DTA) curve or a DSC curve is prepared.
• DTA differential thermal analysis
• the extrapolated glass transition onset temperature (Tig), i.e., the glass transition temperature Tg in this specification, is determined as the temperature at the intersection of a straight line extending the low-temperature side baseline of a DTA curve or DSC curve to the high-temperature side and a tangent drawn at the point where the gradient of the curve of the stepwise change in the glass transition is maximum.
• the Tg of the thermoplastic resin contained in the thermoplastic resin particles is determined as follows.
• the Tg of the first thermoplastic resin is Tg1(K)
• the mass fraction of the first thermoplastic resin relative to the total mass of the thermoplastic resin components in the thermoplastic resin particles is W1
• the second Tg is Tg2(K)
• the mass fraction of the second resin relative to the total mass of the thermoplastic resin components in the thermoplastic resin particles is W2
• the Tg0(K) of the thermoplastic resin particles can be estimated according to the following FOX formula.
• thermoplastic resin particles contain three types of resins or when three types of thermoplastic resin particles containing different types of thermoplastic resins are contained in the pretreatment liquid, the Tg of the thermoplastic resin particles can be estimated according to the following formula, as described above, where Tgn(K) is the Tg of the nth resin and Wn is the mass fraction of the nth resin relative to the total mass of the resin components in the thermoplastic resin particles.
• FOX formula: 1/Tg0 (W1/Tg1)+(W2/Tg2)+(W3/Tg3)...+(Wn/Tgn)
• Tg is a value measured by a differential scanning calorimetry (DSC).
• DSC differential scanning calorimetry
• EXSTAR6220 manufactured by SII NanoTechnology can be used as the differential scanning calorimetry (DSC).
• the arithmetic mean particle diameter of the thermoplastic resin particles is preferably 1 nm or more and 200 nm or less, more preferably 3 nm or more and less than 80 nm, and even more preferably 10 nm or more and 49 nm or less.
• thermoplastic resin particles in this disclosure refers to a value measured by dynamic light scattering (DLS).
• the arithmetic mean particle size of thermoplastic resin particles by DLS is measured using a Brookhaven BI-90 (manufactured by Brookhaven Instrument Company) in accordance with the manual for the said instrument.
• the weight average molecular weight of the thermoplastic resin contained in the thermoplastic resin particles is preferably 3,000 to 300,000, and more preferably 5,000 to 100,000.
• the method for producing the thermoplastic resin contained in the thermoplastic resin particles is not particularly limited, and the thermoplastic resin can be produced by a known method.
• the thermoplastic resin can be produced by a known method.
• it can be obtained by polymerizing, by a known method, a styrene compound, an acrylonitrile compound, and, as necessary, at least one compound selected from the group consisting of the N-vinyl heterocyclic compound, the compound used to form the structural unit having an ethylenically unsaturated group, the compound used to form the structural unit having an acidic group, the compound used to form the structural unit having a hydrophobic group, and the compound used to form the other structural units.
• thermoplastic resins contained in the thermoplastic resin particles are shown in the table below, but the thermoplastic resins used in this disclosure are not limited to these.
• the content ratio of each structural unit can be appropriately changed in accordance with the preferred range of the content of each structural unit described above.
• the weight average molecular weight of each of the specific compounds can be appropriately changed in accordance with the preferred range of the weight average molecular weight of the thermoplastic resin described above.
• the average particle size of the above particles is preferably 0.01 ⁇ m to 3.0 ⁇ m, more preferably 0.03 ⁇ m to 2.0 ⁇ m, and even more preferably 0.10 ⁇ m to 1.0 ⁇ m, in which case good resolution and stability over time can be obtained.
• the average primary particle size of the particles in the present disclosure is measured by a light scattering method, or by taking an electron microscope photograph of the particles, measuring the particle sizes of 5,000 particles in total on the photograph, and calculating the average value. Note that for non-spherical particles, the particle size is the particle size value of a spherical particle having the same particle area as the particle area on the photograph.
• the average particle size in this disclosure is taken to be the volume average particle size unless otherwise specified.
• the image recording layer may contain one type of particles, particularly polymer particles, or may contain two or more types.
• the content of particles, particularly polymer particles, in the image recording layer is preferably 5% by mass to 90% by mass, more preferably 10% by mass to 90% by mass, even more preferably 20% by mass to 90% by mass, and particularly preferably 50% by mass to 90% by mass, relative to the total mass of the image recording layer.
• the content of the polymer particles in the image recording layer is preferably 20% by mass to 100% by mass, more preferably 35% by mass to 100% by mass, even more preferably 50% by mass to 100% by mass, and particularly preferably 80% by mass to 100% by mass, relative to the total mass of the components having a molecular weight of 3,000 or more in the image recording layer.
• the image recording layer may contain a binder polymer.
• a binder polymer used in the image recording layer of an on-press development type lithographic printing plate precursor can be used.
• the binder polymer the binder polymers described in paragraphs 0288 to 0317 of WO 2022/019217 can be suitably used.
• the binder polymer may be used alone or in combination of two or more kinds.
• the binder polymer can be contained in any amount in the image recording layer, but the content of the binder polymer is preferably 1% by mass to 90% by mass, and more preferably 5% by mass to 80% by mass, based on the total mass of the image recording layer.
• the content of the other binder polymer relative to the total mass of the thermoplastic resin particles and the other binder polymer is preferably more than 0 mass% and not more than 99 mass%, more preferably 20 mass% to 95 mass%, and even more preferably 40 mass% to 90 mass%.
• the image recording layer also preferably contains an oil agent.
• the oil agent in this disclosure refers to a hydrophobic compound that is in a liquid state at 80° C. and is immiscible with and separates from water when mixed with the same mass of water. When two or more oil agents are used, even if the oil agent contains a compound having a melting point of 80°C or higher, it is sufficient that the two or more oil agents are in a liquid state at 80°C when mixed together.
• the oil agent is preferably a compound having a molecular weight of less than 1,000, more preferably a compound having a molecular weight of 200 to 800, and particularly preferably a compound having a molecular weight of 300 to 500. Furthermore, from the viewpoints of on-press developability and suppression of turbidity of the dampening water, the oil agent is preferably a compound having a boiling point of 200° C. or more at 1 atmospheric pressure, more preferably a compound having a boiling point of 250° C. or more at 1 atmospheric pressure, even more preferably a compound having a boiling point of 300° C.
• boiling point refers to the boiling point at 1 atmospheric pressure.
• the melting point of the oil agent at 1 atmospheric pressure is preferably 50° C. or lower, more preferably 30° C. or lower, and particularly preferably ⁇ 200° C. or higher and 25° C. or lower, from the viewpoints of on-press developability and suppression of turbidity of the dampening water.
• melting point refers to the melting point at 1 atmosphere.
• the oil agent examples include a phosphate ester compound, an aromatic hydrocarbon compound, a glyceride compound, a fatty acid compound, and an aromatic ester compound.
• a phosphate ester compound an aromatic hydrocarbon compound
• a glyceride compound a fatty acid compound
• an aromatic ester compound examples include a phosphate ester compound, an aromatic hydrocarbon compound, a glyceride compound, a fatty acid compound, and an aromatic ester compound.
• at least one compound selected from the group consisting of phosphoric acid ester compounds, aromatic hydrocarbon compounds, glyceride compounds, and aromatic ester compounds is preferred, at least one compound selected from the group consisting of phosphoric acid ester compounds, aromatic hydrocarbon compounds, and glyceride compounds is more preferred, at least one compound selected from the group consisting of phosphoric acid ester compounds and aromatic hydrocarbon compounds is even more preferred, and phosphoric acid ester compounds are particularly preferred.
• a phosphate ester compound from the viewpoints of printing durability, ink receptivity, on-press developability, and suppression of turbidity in dampening water, a phosphate triester compound is preferred, a triaryl phosphate ester compound is more preferred, tricresyl phosphate is even more preferred, and a mixture of two or more of the three types of tricresyl phosphate, i.e., the ortho-, meta-, and para-isomers, is particularly preferred.
• aromatic hydrocarbon compound from the viewpoints of on-press developability and suppression of turbidity of the fountain solution, a compound having two or more aromatic rings is preferred, and a compound having two or more non-condensed benzene rings is more preferred.
• a triglyceride compound from the viewpoints of on-press developability and suppression of turbidity of the fountain solution, a triglyceride compound is preferable, a fatty oil is more preferable, and a fatty oil that is liquid at 25° C., such as castor oil, is particularly preferable.
• fatty acid compound from the viewpoints of on-press developability and suppression of turbidity of the dampening water, unsaturated fatty acids are preferred, unsaturated fatty acids having 8 to 30 carbon atoms are more preferred, and unsaturated fatty acids having 12 to 24 carbon atoms are particularly preferred.
• aromatic ester compound from the viewpoints of on-press developability and suppression of turbidity of the fountain solution, an aromatic diester compound is preferred, and an aromatic diester compound having an aliphatic ring is more preferred.
• an aliphatic ester compound having a branched alkyl group is preferable, and an aliphatic ester compound having a branched alkyl group and having 10 to 24 carbon atoms is more preferable.
• the oil agent preferably contains an oil agent having a phosphorus atom, and is more preferably an oil agent having a phosphorus atom.
• the oil agent preferably contains an oil agent having an aromatic ring, more preferably contains an oil agent having two or more aromatic rings, and particularly preferably contains an oil agent having two or more non-condensed benzene rings.
• the clogP value of the oil agent is preferably 5.0 or more, more preferably 5.50 or more, even more preferably 5.50 or more and 10.0 or less, and particularly preferably 5.60 or more and 7.00 or less.
• the clogP value is a value obtained by calculating the common logarithm logP of the partition coefficient P between 1-octanol and water.
• Known methods and software can be used to calculate the clogP value, but unless otherwise specified, the present disclosure uses the ClogP program incorporated in Cambridge Soft's ChemBioDraw Ultra 12.0.
• oil agents include tricresyl phosphate, dimethyl (1-phenylethyl) benzene, 2,4-diphenyl-4-methyl-1-pentene, dicyclohexyl phthalate, castor oil, ⁇ -linolenic acid, and tri(2-ethylhexyl) phosphate.
• the oil agent may be used alone or in combination of two or more types. However, from the viewpoints of on-press developability and suppression of turbidity of the dampening water, it is preferable that the image recording layer contains two or more types of oil agents having different structures.
• the content of the oil agent is preferably from 0.0001% by mass to 10.0% by mass, more preferably from 0.0002% by mass to 1.0% by mass, even more preferably from 0.0005% by mass to 0.5% by mass, and particularly preferably from 0.001% by mass to 0.05% by mass, based on the total mass of the image recording layer.
• the image recording layer may contain a chain transfer agent.
• a chain transfer agent used in the image recording layer of an on-press development type lithographic printing plate precursor can be used.
• the chain transfer agent the chain transfer agents described in paragraphs 0388 to 0393 of WO 2022/019217 can be suitably used.
• the chain transfer agent may be used alone or in combination of two or more kinds.
• the content of the chain transfer agent is preferably from 0.01% by mass to 50% by mass, more preferably from 0.05% by mass to 40% by mass, and even more preferably from 0.1% by mass to 30% by mass, based on the total mass of the image recording layer.
• the image recording layer may contain an oil sensitizer to improve ink receptivity.
• an oil sensitizer used in the image recording layer of an on-press development type lithographic printing plate precursor can be used.
• the oil sensitizers described in paragraphs 0395 to 0404 of WO 2022/019217 can be suitably used.
• the content of the oil sensitizer is preferably 1% by mass to 40.0% by mass, more preferably 2% by mass to 25.0% by mass, and even more preferably 3% by mass to 20.0% by mass, based on the total mass of the image recording layer.
• the image recording layer may contain one type of oil sensitizer alone or two or more types of oil sensitizers in combination.
• One of the preferred embodiments of the image recording layer used in the present disclosure is an embodiment containing two or more compounds as oil sensitizers.
• the image recording layer used in the present disclosure preferably uses, as the oil sensitizer, a phosphonium compound, a nitrogen-containing low molecular weight compound, and an ammonium group-containing polymer in combination, and more preferably uses a phosphonium compound, a quaternary ammonium salt, and an ammonium group-containing polymer in combination.
• the image-recording layer preferably further contains a development accelerator.
• the development accelerator preferably has a polarity term SP value of 6.0 to 26.0, more preferably 6.2 to 24.0, further preferably 6.3 to 23.5, and particularly preferably 6.4 to 22.0.
• the polar term value of the SP value is the polar term ⁇ p value in the Hansen solubility parameter.
• the Hansen solubility parameter is a solubility parameter introduced by Hildebrand, which is divided into three components, a dispersion term ⁇ d, a polar term ⁇ p, and a hydrogen bond term ⁇ h, and expressed in three-dimensional space, but in this disclosure, the polar term ⁇ p is used.
• ⁇ p [cal/cm 3 ] is the Hansen solubility parameter dipole-dipole force term
• V [cal/cm 3 ] is the molar volume
• ⁇ [D] is the dipole moment.
• the following formula simplified by Hansen and Beerbower is used for ⁇ p.
• the development accelerator is preferably a hydrophilic high molecular weight compound or a hydrophilic low molecular weight compound.
• hydrophilic refers to a polar term of the SP value being 6.0 to 26.0
• hydrophilic polymer compound refers to a compound having a molecular weight (weight average molecular weight when the molecular weight distribution is present) of 3,000 or more
• hydrophilic low molecular weight compound refers to a compound having a molecular weight (weight average molecular weight when the molecular weight distribution is present) of less than 3,000.
• hydrophilic polymer compound examples include cellulose compounds, and the like, with cellulose compounds being preferred.
• the cellulose compound includes cellulose and a compound in which cellulose is at least partially modified (that is, a modified cellulose compound), and the modified cellulose compound is preferred.
• Preferred examples of modified cellulose compounds include compounds in which at least a portion of the hydroxy groups of cellulose are substituted with at least one group selected from the group consisting of alkyl groups and hydroxyalkyl groups.
• the degree of substitution of the compound in which at least a portion of the hydroxy groups of the cellulose is substituted with at least one group selected from the group consisting of alkyl groups and hydroxyalkyl groups is preferably 0.1 to 6.0, and more preferably 1 to 4.
• the modified cellulose compound is preferably an alkyl cellulose compound or a hydroxyalkyl cellulose compound, more preferably a hydroxyalkyl cellulose compound.
• a preferred example of the alkyl cellulose compound is methyl cellulose.
• a preferred example of the hydroxyalkyl cellulose compound is hydroxypropyl cellulose.
• the molecular weight of the hydrophilic polymer compound (however, if it has a molecular weight distribution, the weight average molecular weight) is preferably 3,000 to 5,000,000, and more preferably 5,000 to 200,000.
• Hydrophilic low molecular weight compounds include glycol compounds, polyol compounds, organic amine compounds, organic sulfonic acid compounds, organic sulfamine compounds, organic sulfuric acid compounds, organic phosphonic acid compounds, organic carboxylic acid compounds, betaine compounds, etc., with polyol compounds, organic sulfonic acid compounds, and betaine compounds being preferred.
• glycol compound examples include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, and ether or ester derivatives of these compounds.
• polyol compound examples include glycerin, pentaerythritol, and tris(2-hydroxyethyl)isocyanurate.
• the organic amine compound includes triethanolamine, diethanolamine, monoethanolamine, and the like, and salts thereof.
• Examples of the organic sulfonic acid compound include alkylsulfonic acid, toluenesulfonic acid, benzenesulfonic acid, and salts thereof, and preferable examples include alkylsulfonic acids in which the alkyl group has 1 to 10 carbon atoms.
• the organic sulfamine compounds include alkylsulfamic acids and their salts.
• the organic sulfate compound includes alkyl sulfates, alkyl ether sulfates, and salts thereof.
• the organic phosphonic acid compounds include phenylphosphonic acid and salts thereof.
• the organic carboxylic acid compound includes tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, and the like, and salts thereof.
• betaine compound include a phosphobetaine compound, a sulfobetaine compound, and a carboxybetaine compound, and a preferred example is trimethylglycine.
• the molecular weight of the hydrophilic low molecular weight compound (however, if it has a molecular weight distribution, the weight average molecular weight) is preferably 100 or more and less than 3,000, and more preferably 300 to 2,500.
• the development accelerator is preferably a compound having a cyclic structure.
• the cyclic structure is not particularly limited, but examples thereof include a glucose ring in which at least a portion of a hydroxy group may be substituted, an isocyanuric ring, an aromatic ring which may have a heteroatom, and an aliphatic ring which may have a heteroatom, and is preferably a glucose ring or an isocyanuric ring.
• Examples of the compound having a glucose ring include the above-mentioned cellulose compounds.
• the compound having an isocyanuric ring includes the above-mentioned tris(2-hydroxyethyl)isocyanurate.
• Examples of the compound having an aromatic ring include the above-mentioned toluenesulfonic acid and benzenesulfonic acid.
• Examples of the compound having an aliphatic ring include the above-mentioned alkyl sulfate in which the alkyl group has a ring structure.
• the compound having a cyclic structure preferably has a hydroxy group.
• Preferred examples of the compound having a hydroxy group and a cyclic structure include the above-mentioned cellulose compound and the above-mentioned tris(2-hydroxyethyl)isocyanurate.
• the development accelerator is preferably an onium salt compound.
• the onium salt compound includes ammonium compounds and sulfonium compounds, and the ammonium compounds are preferred.
• the onium salt compound development accelerator includes trimethylglycine.
• the onium salt compound in the electron-accepting polymerization initiator is a compound in which the polarity term of the SP value is not in the range of 6.0 to 26.0, and is not included in the development accelerator.
• the image recording layer may contain one type of development accelerator alone or two or more types of development accelerators in combination.
• one of the preferred embodiments of the image recording layer is an embodiment in which the image recording layer contains two or more compounds as development accelerators.
• the image recording layer contains, as a development accelerator, the above-mentioned polyol compound and the above-mentioned betaine compound, the above-mentioned betaine compound and the above-mentioned organic sulfonic acid compound, or the above-mentioned polyol compound and the above-mentioned organic sulfonic acid compound.
• the content of the development accelerator relative to the total mass of the image recording layer is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and even more preferably 1% by mass or more and 10% by mass or less.
• the image recording layer preferably contains a surfactant from the viewpoints of accelerating on-press developability and improving the coating surface.
• the surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a fluorine-based surfactant, etc.
• the surfactant may be used alone or in combination of two or more kinds.
• the nonionic surfactant used in the present disclosure is not particularly limited, and any of those conventionally known may be used.
• polyoxyethylene alkyl ethers polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N,N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine
• the anionic surfactant used in the present disclosure is not particularly limited, and any of those known in the art can be used.
• fatty acid salts, abietic acid salts, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinate salts linear alkylbenzenesulfonates, branched alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates, polyoxyethylenealkylsulfophenylether salts, N-methyl-N-oleyltaurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef tallow oil, sulfate ester salts of fatty acid alkyl esters, alkane sulfonates, dialkylsulfosuccinate salts ...
• alkyl sulfate salts examples include alkyl sulfate salts, polyoxyethylene alkyl ether sulfate salts, fatty acid monoglyceride sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, polyoxyethylene styryl phenyl ether sulfate salts, alkyl phosphate salts, polyoxyethylene alkyl ether phosphate salts, polyoxyethylene alkyl phenyl ether phosphate salts, partially saponified products of styrene/maleic anhydride copolymers, partially saponified products of olefin/maleic anhydride copolymers, and naphthalene sulfonate formalin condensates.
• the cationic surfactant used in the present disclosure is not particularly limited, and any conventionally known surfactant may be used.
• alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives may be mentioned.
• the amphoteric surfactant used in the present disclosure is not particularly limited, and any conventionally known surfactant may be used.
• carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid esters, and imitazolines may be used.
• polyoxyethylene can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, etc., and these surfactants can also be used in this disclosure.
• More preferred surfactants include fluorosurfactants containing a perfluoroalkyl group in the molecule.
• fluorosurfactants include anionic types such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl phosphates; amphoteric types such as perfluoroalkyl betaines; cationic types such as perfluoroalkyl trimethyl ammonium salts; and nonionic types such as perfluoroalkyl amine oxides, perfluoroalkyl ethylene oxide adducts, oligomers containing perfluoroalkyl groups and hydrophilic groups, oligomers containing perfluoroalkyl groups and lipophilic groups, oligomers containing perfluoroalkyl groups, hydrophilic groups, and lipophilic groups, and urethanes containing perfluoroalkyl groups and lipophilic groups.
• surfactants such as amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149, siloxane compounds as described in EP 950517, fluorine-containing monomer copolymers as described in JP-A-11-288093, and fluorine-based surfactants as described in JP-A-62-170950 can be added to improve the stability of the processing under the development conditions of the present disclosure or to improve the coatability of the coating, without impairing the effects of the present disclosure.
• amphoteric surfactants include alkyldi(aminoethyl)glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, and N-tetradecyl-N,N-betaine type (for example, trade name "Amogene K” manufactured by Daiichi Kogyo Co., Ltd.).
• siloxane-based compound a block copolymer of dimethylsiloxane and polyalkylene oxide is preferable, and specific examples include polyalkylene oxide-modified silicones such as DBE-224, DBE-621, DBE-712, DBP-732, DBP-534 manufactured by Chisso Corporation, and Tego Glide 100 manufactured by Tego GmbH of Germany.
• polyalkylene oxide-modified silicones such as DBE-224, DBE-621, DBE-712, DBP-732, DBP-534 manufactured by Chisso Corporation, and Tego Glide 100 manufactured by Tego GmbH of Germany.
• Products manufactured by Dow Toray Co., Ltd. include DOWSIL BY 16-205, DOWSIL BY 16-849 Fluid, DOWSIL FZ-3710 Fluid, DOWSIL FZ-3760, DOWSIL FZ-3785, DOWSIL SF 8417 Fluid, DOWSIL BY 16-891, DOWSIL FZ-3789, DOWSIL BY 16-839 Fluid, DOWSIL SF 8411 Fluid, DOWSIL SF 8413 Fluid, DOWSIL SF 8421 Fluid, DOWSIL BY 16-880 Fluid, DOWSIL BY 16-201, DOW SIL SF 8427 Fluid, DOWSIL SF 8428 Fluid, DOWSIL 580 WAX, DOWSIL BY 16-606, DOWSIL BY 16-846 Fluid, XIAM ETER OFX-0203 Fluid, XIAMETER OFX-0230 Fluid, DOWS IL SF 8416 Fluid, DOWSIL SF 8419 Fluid, DOWSIL 501W Additive, DOWSIL FZ-21
• Shin-Etsu Silicone (registered trademark) products from Shin-Etsu Chemical Co., Ltd. include the KP series: KP-124, KP-109, KP-110, KP-121, KP-118, KP-341, KP-112, KP-125, KP-101, KP-106, KP-120, KP-105, KP-104, KP-611, KP-626, KP-327, KP-323, KP-322, KP-625, KP-623, KP-624, KP-620, and KP-651.
• BYK products include BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315 N, BYK-320, B YK-322, BYK-323, BYK-325 N, BYK-326*, BYK-327*, BYK-330, BYK-331, BYK-333, BYK-342, BYK- 345/346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-375, BYK-377, BYK-378, BYK-3450*, BYK-3 451*, BYK-3455, BYK-3456*, BYK-3760*, BYK-UV 3500, BYK-UV 3505*, BYK-UV 3510, BYK-UV 35 30, BYK-UV 3535*, BYK-UV 3570, BYK-UV 3575
• the image recording layer may contain, as other components, a polymerization inhibitor, a higher fatty acid derivative, a plasticizer, inorganic particles, an inorganic layer compound, etc.
• a polymerization inhibitor for details, refer to the description in paragraphs 0121 to 0159 of JP-A-2008-284817.
• the image recording layer in the lithographic printing plate precursor according to the present disclosure can be formed by dispersing or dissolving the above-mentioned necessary components in a known solvent to prepare a coating liquid, applying the coating liquid onto a support by a known method such as bar coater coating, and drying, as described in, for example, paragraphs [0142] to [0143] of JP2008-195018A.
• the coating amount (solid content) of the image recording layer after coating and drying varies depending on the application, but is preferably 0.3 g/ m2 to 3.0 g/ m2 . Within this range, good sensitivity and good film properties of the image recording layer can be obtained.
• the solvent a known solvent can be used.
• the solvent include water, acetone, methyl ethyl ketone (2-butanone), cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 1-methoxy-2-propanol, 3-methoxy-1-propanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene
• the solvent may be used alone or in combination of two or more.
• the solid content in the coating solution is preferably 1% by mass to 50% by mass.
• the coating amount (solid content) of the image recording layer after coating and drying varies depending on the application, but is preferably 0.3 g/m 2 to 3.0 g/m 2 from the viewpoint of obtaining good sensitivity and good film properties of the image recording layer.
• the film thickness of the image recording layer in the lithographic printing plate precursor according to the present disclosure is preferably 0.1 ⁇ m to 3.0 ⁇ m, and more preferably 0.3 ⁇ m to 2.0 ⁇ m.
• the film thickness of each layer in the lithographic printing plate precursor is confirmed by preparing a slice by cutting the lithographic printing plate precursor in a direction perpendicular to its surface and observing the cross section of the slice with a scanning electron microscope (SEM).
• SEM scanning electron microscope
• the lithographic printing plate precursor according to the present disclosure has a support.
• the support can be appropriately selected from known supports for lithographic printing plate precursors.
• the support is preferably one having a hydrophilic surface.
• the support in this disclosure is preferably an aluminum plate that has been roughened and anodized by a known method. That is, the support in this disclosure preferably has an aluminum plate and an anodized aluminum coating disposed on the aluminum plate.
• the support has an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the anodized film being located closer to the image recording layer than the aluminum plate, the anodized film having micropores extending in the depth direction from the surface on the image recording layer side, and the average diameter of the micropores on the surface of the anodized film being greater than 10 nm and not greater than 100 nm.
• the micropores are composed of large diameter pores extending from the surface of the anodized film to a depth of 10 nm to 1,000 nm, and small diameter pores that communicate with the bottoms of the large diameter pores and extend from the communicating position to a depth of 20 nm to 2,000 nm, the large diameter pores having an average diameter of 15 nm to 100 nm at the surface of the anodized film, and the small diameter pores having an average diameter of 13 nm or less at the communicating positions.
• FIG. 1 is a schematic cross-sectional view of one embodiment of an aluminum support 12a.
• the aluminum support 12a has a laminated structure in which an aluminum plate 18 and an aluminum anodized film 20a (hereinafter also simply referred to as "anodized film 20a") are laminated in this order.
• the anodized film 20a in the aluminum support 12a is located closer to the image recording layer than the aluminum plate 18.
• the lithographic printing plate precursor according to the present disclosure preferably has at least an anodized film, an image recording layer, and a water-soluble resin layer, in this order, on the aluminum plate.
• the anodized film 20a is a film produced on the surface of the aluminum plate 18 by anodizing, and has extremely fine micropores 22a that are approximately perpendicular to the film surface and are distributed approximately uniformly.
• the micropores 22a extend from the surface of the anodized film 20a on the image recording layer side (i.e., the surface of the anodized film 20a on the side opposite to the aluminum plate 18) along the thickness direction (i.e., toward the aluminum plate 18).
• the average diameter (i.e., average opening diameter) of the micropores 22a in the anodized coating 20a at the surface of the anodized coating is preferably more than 10 nm and not more than 100 nm.
• a diameter of 15 nm to 60 nm is more preferable, 20 nm to 50 nm is even more preferable, and 25 nm to 40 nm is particularly preferable.
• the diameter inside the pores may be wider or narrower than that at the surface layer. When the average diameter exceeds 10 nm, printing durability and image visibility are excellent, and when the average diameter is 100 nm or less, printing durability is excellent.
• FE-SEM field emission scanning electron microscope
• the shape of the micropores 22a is not particularly limited, and in FIG. 1, they are substantially straight (i.e., substantially cylindrical), but they may also be conical with a diameter that decreases in the depth direction (thickness direction).
• the shape of the bottom of the micropores 22a is not particularly limited, and may be curved (convex) or flat.
• the micropores may be composed of a large diameter pore portion extending from the surface of the anodized coating to a certain depth position, and a small diameter pore portion communicating with the bottom of the large diameter pore portion and extending from the communicating position to a certain depth position.
• an aluminum support 12 b may include an aluminum plate 18 and an anodized film 20 b having micropores 22 b each having a large diameter portion 24 and a small diameter portion 26 .
• the micropores 22b in the anodized film 20b are composed of a large diameter hole portion 24 extending from the surface of the anodized film to a depth of 10 nm to 1000 nm (depth D: see FIG.
• ⁇ Method of manufacturing support>> As a method for producing a support used in the present disclosure, for example, a production method in which the following steps are carried out in order is preferable.
• Surface roughening process a process of roughening the surface of an aluminum plate;
• Anodizing process a process of anodizing the surface-roughened aluminum plate;
• Pore widening process a process of contacting the aluminum plate having the anodized film obtained in the anodizing process with an acid aqueous solution or an alkaline aqueous solution to enlarge the diameter of the micropores in the anodized film. The procedure for each process is described in detail below.
• the surface roughening process is a process of performing a surface roughening process including an electrochemical surface roughening process on the surface of an aluminum plate. This process is preferably performed before the anodizing process described later, but may not be performed if the surface of the aluminum plate already has a preferred surface shape. It can be performed by the method described in paragraphs 0086 to 0101 of JP 2019-162855 A.
• the procedure for the anodizing treatment step is not particularly limited as long as the above-mentioned micropores can be obtained, and known methods can be used.
• an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid, etc. can be used as an electrolytic bath.
• the concentration of sulfuric acid is 100 g/L to 300 g/L.
• the conditions for the anodizing treatment are appropriately set depending on the electrolytic solution used, and examples thereof include a solution temperature of 5°C to 70°C (preferably 10°C to 60°C), a current density of 0.5 A/ dm2 to 60 A/ dm2 (preferably 1 A/ dm2 to 60 A/ dm2 ), a voltage of 1 V to 100 V (preferably 5 V to 50 V), an electrolysis time of 1 sec to 100 sec (preferably 5 sec to 60 sec), and a coating weight of 0.1 g/ m2 to 5 g/ m2 (preferably 0.2 g/ m2 to 3 g/ m2 ).
• the pore widening treatment is a treatment for enlarging the diameter (i.e., pore diameter) of the micropores present in the anodized film formed by the above-mentioned anodizing treatment step (i.e., pore diameter enlarging treatment).
• the pore widening treatment can be carried out by contacting the aluminum plate obtained by the above-mentioned anodizing treatment step with an acid aqueous solution or an alkaline aqueous solution.
• the contacting method is not particularly limited, and examples thereof include a dipping method and a spraying method.
• the support may have a backcoat layer containing an organic polymer compound described in JP-A-5-45885 or a silicon alkoxy compound described in JP-A-6-35174 on the side opposite the image recording layer.
• the lithographic printing plate precursor according to the present disclosure preferably has an undercoat layer (sometimes called an intermediate layer) between the image recording layer and the support.
• the undercoat layer strengthens the adhesion between the support and the image recording layer in the exposed area and makes it easier for the image recording layer to peel off from the support in the unexposed area, thereby contributing to improving developability while suppressing a decrease in printing durability.
• the undercoat layer functions as a heat insulating layer, thereby preventing the heat generated by exposure from diffusing to the support and decreasing sensitivity.
• the compounds used in the undercoat layer include polymers having adsorptive groups and hydrophilic groups that can be adsorbed to the support surface. In order to improve adhesion to the image recording layer, polymers having adsorptive groups and hydrophilic groups and also having crosslinkable groups are preferred.
• the compounds used in the undercoat layer may be low molecular weight compounds or polymers. Two or more types of compounds may be mixed together as necessary.
• the compound used in the undercoat layer is a polymer
• it is preferably a copolymer of a monomer having an adsorptive group, a monomer having a hydrophilic group, and a monomer having a crosslinkable group.
• the adsorptive group capable of being adsorbed onto the surface of the support include a phenolic hydroxy group, a carboxy group , -PO3H2 , -OPO3H2 , -CONHSO2- , -SO2NHSO2- , and -COCH2COCH3 .
• Preferred examples of the hydrophilic group include a sulfo group or a salt thereof, and a salt of a carboxy group.
• the crosslinkable group include an acryl group, a methacryl group, an acrylamide group, a methacrylamide group, and an allyl group.
• the polymer may have a crosslinkable group introduced by salt formation between a polar substituent of the polymer and a compound having an ethylenically unsaturated bond and a substituent having an opposite charge to the polar substituent, or may further be copolymerized with a monomer other than the above-mentioned monomers, preferably a hydrophilic monomer.
• suitable compounds include silane coupling agents having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679 and phosphorus compounds having an ethylenic double bond reactive group described in JP-A-2-304441.
• low-molecular or high-molecular compounds having a crosslinkable group (preferably an ethylenically unsaturated bond group), a functional group that interacts with the support surface, and a hydrophilic group described in JP-A-2005-238816, JP-A-2005-125749, JP-A-2006-239867, and JP-A-2006-215263.
• More preferred examples include polymers having an adsorptive group, a hydrophilic group and a crosslinkable group capable of being adsorbed onto the surface of a support, as described in JP-A-2005-125749 and JP-A-2006-188038.
• the content of the ethylenically unsaturated bond group in the polymer used in the undercoat layer is preferably from 0.1 mmol to 10.0 mmol, more preferably from 0.2 mmol to 5.5 mmol, per gram of the polymer.
• the weight average molecular weight (Mw) of the polymer used in the undercoat layer is preferably 5,000 or more, and more preferably from 10,000 to 300,000.
• the undercoat layer may contain chelating agents, secondary or tertiary amines, polymerization inhibitors, compounds having an amino group or a functional group having polymerization inhibitory ability and a group that interacts with the support surface (e.g., 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,3,5,6-tetrahydroxy-p-quinone, chloranil, sulfophthalic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylenediaminediacetic acid, hydroxyethyliminodiacetic acid, etc.) to prevent staining over time.
• chelating agents e.g., 1,4-diazabicyclo[2.2.2]octane (DABCO), 2,3,5,6-tetrahydroxy-p-quinone, chloranil, sulfophthalic acid, hydroxyethylethylenediaminetriacetic acid, dihydroxyethylethylene
• the undercoat layer is applied by a known method.
• the coating amount of the undercoat layer (solid content) is preferably 0.1 mg/m 2 to 100 mg/m 2 , and more preferably 1 mg/m 2 to 30 mg/m 2 .
• the lithographic printing plate precursor according to the present disclosure may have an outermost layer (sometimes called a "protective layer” or “overcoat layer”) on the surface of the image recording layer opposite the support.
• the lithographic printing plate precursor according to the present disclosure preferably has a support, an image recording layer, and an outermost layer in this order.
• the outermost layer may have a function of preventing the occurrence of scratches in the image recording layer and ablation during exposure to high-intensity laser light, in addition to a function of suppressing image formation inhibiting reactions by blocking oxygen.
• the outermost layer may be a known outermost layer ("protective layer” or “overcoat layer”) in an on-press development type lithographic printing plate precursor. Specifically, the outermost layer described in paragraphs 0444 to 0462 of WO 2022/019217 can be suitably used.
• the lithographic printing plate precursor according to the present disclosure may have layers other than those described above.
• the other layers are not particularly limited, and any known layers may be used.
• a backcoat layer may be provided on the side of the support opposite to the image recording layer, if necessary.
• a lithographic printing plate can be prepared by imagewise exposing the lithographic printing plate precursor according to the present disclosure and then subjecting it to a development treatment.
• the method for producing a lithographic printing plate according to the present disclosure preferably includes a step of exposing the on-press development-type lithographic printing plate precursor according to the present disclosure in an imagewise manner (hereinafter also referred to as an "exposure step"), and a step of supplying at least one selected from the group consisting of printing ink and fountain solution on the printing press to remove the image recording layer in non-image areas (hereinafter also referred to as an "on-press development step").
• the lithographic printing method preferably includes a step of exposing the on-press development-type lithographic printing plate precursor according to the present disclosure in an imagewise manner (i.e., an exposure step), a step of removing the image recording layer in the non-image areas on the printing press by supplying at least one selected from the group consisting of printing ink and fountain solution to prepare a lithographic printing plate (i.e., an on-press development step), and a step of printing with the obtained lithographic printing plate (i.e., a printing step).
• a method for producing a lithographic printing plate preferably includes a step of imagewise exposing an on-press development type lithographic printing plate precursor to an infrared laser, and a step of removing the image recording layer in non-image areas by supplying at least one selected from the group consisting of printing ink and fountain solution on a printing press, wherein the on-press development type lithographic printing plate precursor has a support and an image recording layer on the support, the image recording layer contains an infrared absorber capable of donating electrons to the initiator, and a color developer precursor, and when the image recording layer is exposed to an infrared laser having a wavelength of 830 nm and an energy density of 110 mJ/ cm2 , a lightness change ⁇ L of the image recording layer before and after the exposure is 3.0 or more.
• the method for producing a lithographic printing plate preferably comprises the steps of: imagewise exposing an on-press development-type lithographic printing plate precursor to an infrared laser; and removing the image recording layer in non-image areas by supplying at least one selected from the group consisting of printing ink and fountain solution on a printing press, wherein the on-press development-type lithographic printing plate precursor has a support and an image recording layer on the support, the image recording layer contains an initiator, an infrared absorber, and a color-developer precursor, and the image recording layer satisfies the following formula L: 2.0 ⁇ L1-L0 Formula L In the formula L, L1 represents the visibility of the image recording layer, and L0 represents the visibility of a layer which is the same as the image recording layer except for the absence of the color former precursor. Furthermore, with regard to the lithographic printing method according to the present disclosure, each of these aspects preferably further includes the printing step described above.
• the lithographic printing plate precursor according to the present disclosure can also be developed with a developer.
• the exposure step and on-press development step in the method for preparing a lithographic printing plate will be described below, but the exposure step in the method for preparing a lithographic printing plate according to the present disclosure is the same as the exposure step in the lithographic printing method according to the present disclosure, and the on-press development step in the method for preparing a lithographic printing plate according to the present disclosure is the same as the on-press development step in the lithographic printing method according to the present disclosure.
• the method for producing a lithographic printing plate according to the present disclosure preferably includes an exposure step of imagewise exposing the lithographic printing plate precursor according to the present disclosure to form an exposed area and an unexposed area.
• the lithographic printing plate precursor according to the present disclosure is preferably imagewise exposed by laser exposure through a transparent original having a line image, a halftone dot image, or the like, or by laser light scanning based on digital data.
• the wavelength of the light source is preferably 750 nm to 1,400 nm.
• a solid-state laser or a semiconductor laser that emits infrared rays is suitable.
• the output is preferably 100 mW or more
• the exposure time per pixel is preferably 20 microseconds or less
• the amount of irradiation energy is preferably 10 mJ/cm 2 to 300 mJ/cm 2.
• the exposure mechanism may be any of an internal drum type, an external drum type, a flatbed type, and the like. Image exposure can be carried out by a conventional method using a plate setter, etc.
• the lithographic printing plate precursor may be mounted on a printing press and then image exposure may be carried out on the printing press.
• the method for producing a lithographic printing plate according to the present disclosure preferably includes an on-press development step of supplying at least one selected from the group consisting of printing ink and fountain solution on a printing press to remove the image recording layer in non-image areas.
• the on-press development method will be described below.
• On-press development method it is preferable that an oil-based ink and an aqueous component are supplied to the image-exposed lithographic printing plate precursor on a printing press, and the image recording layer in the non-image areas is removed to prepare a lithographic printing plate. That is, after image exposure, the lithographic printing plate precursor is mounted on a printing press as it is without any development treatment, or the lithographic printing plate precursor is mounted on a printing press and then image exposure is performed on the printing press, and then an oil-based ink and an aqueous component are supplied to print.
• the uncured image recording layer is dissolved or dispersed by either or both of the supplied oil-based ink and aqueous component in the non-image area and removed, exposing a hydrophilic surface in that area.
• the image recording layer cured by exposure forms an oil-based ink receptive area having an oleophilic surface.
• the first thing supplied to the plate surface may be an oil-based ink or an aqueous component, but it is preferable to supply an oil-based ink first in order to prevent the aqueous component from being contaminated by the component of the image recording layer that has been removed.
• the lithographic printing plate precursor is developed on the press and used as it is for printing a large number of sheets.
• the oil-based ink and aqueous component printing ink and fountain solution for normal lithographic printing are preferably used.
• the wavelength of the light source is preferably 300 nm to 450 nm or 750 nm to 1,400 nm.
• a light source of 300 nm to 450 nm a lithographic printing plate precursor containing a sensitizing dye having an absorption maximum in this wavelength region in the image recording layer is preferably used, and as a light source of 750 nm to 1,400 nm, the above-mentioned light sources are preferably used.
• a semiconductor laser is suitable as a light source of 300 nm to 450 nm.
• the lithographic printing method includes a printing step of supplying printing ink to a lithographic printing plate to print a recording medium.
• the printing ink is not particularly limited, and various known inks can be used as desired.
• Preferred examples of the printing ink include oil-based inks and ultraviolet-curable inks (i.e., UV inks).
• dampening water may be supplied as necessary.
• the printing step may also be carried out consecutively to the on-press development step without stopping the printing press.
• the recording medium is not particularly limited, and any known recording medium can be used as desired.
• the entire surface of the lithographic printing plate precursor may be heated as necessary before exposure, during exposure, or between exposure and development.
• Such heating promotes the image formation reaction in the image recording layer, and can provide advantages such as improved sensitivity and printing durability and stabilized sensitivity.
• Heating before development is preferably performed under mild conditions of 150°C or less. This embodiment can prevent problems such as hardening of non-image areas. It is preferable to use very strong conditions for heating after development, preferably in the range of 100°C to 500°C. Within the above range, sufficient image strengthening effect can be obtained and problems such as deterioration of the support and thermal decomposition of the image areas can be suppressed.
• the compounds represented by formula (I) and formula (II) are both novel compounds and can be suitably used as electron-donating polymerization initiators. Details and preferred embodiments of the compound represented by formula (I) and the compound represented by formula (II) as the novel compound are the same as those described in the description of the borate compound represented by formula (1) or the borate compound represented by formula (1a). Among them, preferred novel compounds include the compounds represented by the following B-7, B-25, B-26, B-29, and B-30.
• the molecular weight is the weight average molecular weight (Mw), and the ratio of the repeating units is the molar percentage.
• Mw weight average molecular weight
• the weight average molecular weight (Mw) is a value measured as a polystyrene equivalent value by gel permeation chromatography (GPC).
• Example 1-1 Synthesis of compound B-2
• 22 g of tetrahydrofuran and 0.01 g of iodine were added to 1.2 g of magnesium, and the magnesium was activated while stirring.
• 8.1 g of 1-bromo-4-tert-butylbenzene was added thereto to prepare a Grignard reagent.
• 7.8 g of trifluoroborane-diethyl ether complex (46%) was diluted with 22 g of toluene.
• Examples 1-2 to 1-20 Synthesis of compounds B-3 to B-5, B-7 to B-17, B-20, B-21, B-24, B-26, B-29, and B-30] Each compound was synthesized in the same manner as in Example 1-1, except that p-isopropylphenylboronic acid was changed to a boronic acid appropriate for each compound.
• Examples 1-22 and 1-23 Synthesis of Compounds B-27 and B-28
• Compounds B-27 and B-28 were synthesized in the same manner as in Example 1-21, except that the corresponding bromides and iodonium salts in Example 1-21 were changed.
• Example 1-24 Synthesis of compound B-34
• 22 g of tetrahydrofuran and 0.01 g of iodine were added to 1.2 g of magnesium, and the magnesium was activated while stirring.
• 8.1 g of 1-bromo-4-tert-butylbenzene was added thereto to prepare a Grignard reagent.
• 7.8 g of trifluoroborane-diethyl ether complex (46%) was diluted with 22 g of toluene.
• 29 mL of phenylmagnesium bromide-diethyl ether solution (3 M) was added thereto, and the mixture was stirred at room temperature for 30 minutes, after which the Grignard reagent was added.
• the mixture was added to a saturated aqueous sodium carbonate solution, the THF layer was distilled off, and then the mixture was reslurried with toluene to obtain 4.5 g of a white solid.
• 1 g of the white solid and 1 g of the following infrared absorbing agent (IR-3) were dissolved in 8 mL of acetone, and the solution was added to 24 mL of methanol. The obtained crystals were filtered and washed with methanol to obtain 1 g of compound B-31.
• Examples 1-25 to 1-34 Synthesis of compounds B-35 to B-44
• Compounds B-35 to B-44 were synthesized in the same manner as in Example 1-24, except that the corresponding borate compound and the infrared absorbing agent described later were used.
• Example 2-1 Synthesis of compound B-19
• 22 g of tetrahydrofuran and 0.01 g of iodine were added to 1.2 g of magnesium, and the magnesium was activated with stirring.
• 8.1 g of 1-bromo-4-tert-butylbenzene was added to prepare a Grignard reagent.
• 3.9 g of trimethoxyborane-diethyl ether complex (46%) was diluted with 22 g of toluene, and 29 mL of a phenylmagnesium bromide-diethyl ether solution (3 M) was added to the diluted solution. After stirring at room temperature for 30 minutes, the above Grignard reagent was added.
• the mixture was added to a saturated aqueous sodium carbonate solution, and 20 g of Bis(4-tert-butylphenyl)iodonium hexafluorophosphate was further added.
• the THF layer was distilled off, and then reslurried in methanol to obtain 5 g of a white solid.
• Example 2-2 Synthesis of compound B-18
• Compound B-18 was synthesized in the same manner as in Example 2-1, except that the corresponding bromides and iodonium salts were used instead.
• Example 2-3 Synthesis of compound B-45
• Compound B-45 was synthesized in the same manner as in Example 2-1, except that Bis(4-tert-butylphenyl)iodonium hexafluorophosphate was changed to (4-octoxyphenyl)-(2,4,6-trimethoxyphenyl)iodonium 4-methylbenzenesulfonate instead of Bis(4-tert-butylphenyl)iodonium hexafluorophosphate in Example 2-1.
• Example 2-4 Synthesis of compound B-46
• Compound B-46 was synthesized in the same manner as in Example 2-1, except that 1-bromo-4-tert-butylbenzene was changed to 1-bromo-4-methylbenzene.
• Electrochemical graining treatment was performed using an electrolytic solution with a hydrochloric acid concentration of 14 g/L, an aluminum ion concentration of 13 g/L, and a sulfuric acid concentration of 3 g/L, and an alternating current.
• the temperature of the electrolytic solution was 30° C.
• the aluminum ion concentration was adjusted by adding aluminum chloride.
• the waveform of the AC current was a sine wave with symmetrical positive and negative waveforms, the frequency was 50 Hz, the anode reaction time and the cathode reaction time in one AC current cycle were 1:1, and the current density was 75 A/ dm2 at the peak current value of the AC current waveform.
• the total amount of electricity that the aluminum plate was responsible for the anode reaction was 450 C/ dm2 , and the electrolysis was performed four times at 112.5 C/ dm2 each with a current application interval of 4 seconds.
• a carbon electrode was used as the counter electrode of the aluminum plate. Then, a water washing treatment was performed.
• etching treatment was performed by spraying an aqueous solution of caustic soda with a caustic soda concentration of 5% by mass and an aluminum ion concentration of 0.5% by mass onto the aluminum plate after electrochemical graining treatment at a temperature of 45° C.
• the amount of aluminum dissolved on the surface that had been subjected to electrochemical graining treatment was 0.2 g/m 2. Then, a water washing treatment was performed.
• a desmutting treatment was performed using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate with a spray, and the desmutting treatment was performed for 3 seconds.
• the acidic aqueous solution used in the desmutting treatment was an aqueous solution with a sulfuric acid concentration of 170 g/L and an aluminum ion concentration of 5 g/L.
• the liquid temperature was 30°C.
• the first-stage anodizing treatment (also referred to as the first anodizing treatment) was performed using an anodizing treatment apparatus 610 using direct current electrolysis having the structure shown in Fig. 3. Specifically, the first anodizing treatment was performed under the conditions in the "First anodizing treatment" column shown in Table 1 below, and an anodized film of a predetermined film thickness was formed.
• the anodizing apparatus 610 shown in FIG. 3 will now be described. In an anodizing treatment apparatus 610 shown in Fig. 3, an aluminum sheet 616 is transported as indicated by an arrow in Fig. 3.
• the aluminum sheet 616 is charged (+) by a power supply electrode 620. Then, in the power supply tank 612, the aluminum sheet 616 is transported upward by a roller 622, and its direction is changed downward by a nip roller 624, and then the aluminum sheet 616 is transported toward an electrolytic treatment tank 614 in which an electrolytic solution 626 is stored, and its direction is changed horizontally by a roller 628. Next, the aluminum sheet 616 is charged (-) by an electrolytic electrode 630, so that an anodized film is formed on the surface of the aluminum sheet 616, and the aluminum sheet 616 that leaves the electrolytic treatment tank 614 is transported to a subsequent process.
• a roller 622, a nip roller 624, and a roller 628 constitute a direction changing means, and the aluminum sheet 616 is transported in a mountain shape and an inverted U shape in the space between the power supply tank 612 and the electrolytic treatment tank 614 by the rollers 622, 624, and 628.
• the power supply electrode 620 and the electrolytic electrode 630 are connected to a DC power source 634.
• Second anodizing treatment A second stage anodizing treatment (also referred to as second anodizing treatment) was performed using an anodizing treatment apparatus 610 using direct current electrolysis having the structure shown in Fig. 3. Specifically, the second anodizing treatment was performed under the conditions in the "second anodizing treatment" column shown in Table 1 below, and an anodized film of a predetermined film thickness was formed.
• Table 2 summarizes the lightness L * in the L * a * b * color system of the anodized film surface of the micropores of the obtained support, the average diameter and depth of the large-diameter pores of the micropores on the oxide film surface, the average diameter (nm) and depth of the small-diameter pores of the micropores at the connecting positions, the depth (nm) of the large-diameter pores and the small-diameter pores, the micropore density, and the thickness of the anodized film from the bottom of the small-diameter pores to the surface of the aluminum plate (also referred to as the film thickness).
• the amount of film (AD) in the first anodizing treatment column and the amount of film (AD) in the second anodizing treatment column represent the amount of film obtained by each treatment.
• the electrolyte used is an aqueous solution containing the components in Table 1.
• Example 3-47 the following support B was used.
• a desmutting treatment was carried out using an acidic aqueous solution. Specifically, the aluminum plate was sprayed with the acidic aqueous solution and desmutting treatment was carried out for 3 seconds.
• the acidic aqueous solution used in the desmutting treatment was an aqueous solution of 150 g/L of sulfuric acid. The liquid temperature was 30°C.
• hydrochloric acid electrolysis was performed using an electrolytic solution with a hydrochloric acid concentration of 13 g/L, an aluminum ion concentration of 15 g/L, and a sulfuric acid concentration of 1.0 g/L, using an alternating current.
• the temperature of the electrolytic solution was 25° C.
• the aluminum ion concentration was adjusted by adding aluminum chloride.
• the AC current waveform was a sine wave with symmetrical positive and negative waveforms, the frequency was 50 Hz, the anode reaction time and the cathode reaction time in one AC current cycle were 1:1, and the current density was 35 A/ dm2 at the peak current value of the AC current waveform.
• the total amount of electricity that the aluminum plate was responsible for the anode reaction was 320 C/ dm2 , and the electrolysis was performed four times at 80 C/dm2 each with a current interval of 2.5 seconds.
• a carbon electrode was used as the counter electrode of the aluminum plate. Then, a water washing treatment was performed.
• a desmutting treatment was carried out using an acidic aqueous solution. Specifically, the acidic aqueous solution was sprayed onto the aluminum plate for 3 seconds.
• the acidic aqueous solution used in the desmutting treatment had a sulfuric acid concentration of 170 g/L and an aluminum ion concentration of 5 g/L.
• the liquid temperature was 35°C.
• the first stage of anodizing treatment was carried out using an anodizing apparatus using direct current electrolysis with the structure shown in Fig. 3.
• Anodizing treatment was carried out using a 170 g/L aqueous sulfuric acid solution as the electrolytic solution under conditions of a solution temperature of 40°C and a current density of 20 A/dm2, forming an anodized film with a film weight of 0.3 g/ m2 .
• Second stage anodizing The second stage anodizing treatment was carried out using an anodizing apparatus using direct current electrolysis with the structure shown in Fig. 3. Anodizing treatment was carried out using a 170 g/L aqueous sulfuric acid solution as the electrolytic solution under conditions of a solution temperature of 50°C and a current density of 13 A/dm2, forming an anodized film with a film weight of 3.5 g/ m2 .
• undercoat layer-- Coating solution A for forming the undercoat layer was prepared by mixing the following components.
• Undercoat layer compound (U-1 below, 11% aqueous solution): 0.0788 parts Hydroxyethyldiiminodiacetic acid: 0.0280 parts Sodium ethylenediaminetetraacetate tetrahydrate: 0.0499 parts
• Surfactant (Emalex (registered trademark) 710, Nippon Emulsion Co., Ltd.): 0.0016 parts
• Preservative Biohope L, K.I. Kasei Co., Ltd.
• Water 2.8701 parts
• Undercoat layer compound (U-1 below, 11% aqueous solution): 0.0788 parts Sodium gluconate: 0.0700 parts
• Surfactant (Emalex (registered trademark) 710, Nippon Emulsion Co., Ltd.): 0.0016 parts
• Preservative (Biohope L, K.I. Kasei Co., Ltd.): 0.0015 parts Water: 2.870 parts
• the following image recording layer coating solution was applied to the support with a bar and dried in an oven at 120° C. for 40 seconds to form an image recording layer with a dry coating amount of 1.0 g/m 2 .
• Electron donor polymerization initiators described in Tables 3 to 9 Amounts described in Tables 3 to 9
• Infrared absorbents described in Tables 3 to 9 Amounts described in Tables 3 to 9
• Electron acceptor polymerization initiators described in Tables 3 to 9 Amounts described in Tables 3 to 9
• Polymerizable compounds described in Tables 3 to 9 Amounts described in Tables 3 to 9
• Polymer particles described in Tables 3 to 9 Amounts described in Tables 3 to 9
• Binder polymers described in Tables 3 to 9 Amounts described in Tables 3 to 9
• Color formers described in Tables 3 to 9 Phenothiazine: Amounts shown in Tables 3 to 9
• Surfactants shown in Table 4 Amounts shown in Table 4 Anionic surfactant (
• the electron donating polymerization initiators i.e., specific borate compounds or comparative compounds listed in Tables 3 to 9 are detailed below.
• Int-1 Compound having the following structure
• Int-2 Compound having the following structure
• Int-3 Compound having the following structure
• Int-4 Compound having the following structure
• Int-5 Compound having the following structure
• M-1 Compound having the following structure
• M-2 Compound having the following structure
• M-3 Dipentaerythritol pentaacrylate (SR-399, manufactured by Sartomer Co., Ltd.)
• M-4 Urethane acrylate (U-15HA, manufactured by Shin-Nakamura Chemical Co., Ltd.)
• M-5 Monomer synthesized by the following synthesis method
• the reaction solution was added with Neostan U-600 (bismuth-based polycondensation catalyst, manufactured by Nitto Kasei Co., Ltd., 0.11 parts), and heated at 65 ° C. for 4 hours.
• the reaction solution was cooled to room temperature (25 ° C.), and methyl ethyl ketone was added to synthesize a urethane acrylate solution with a solid content of 50% by mass.
• molecular weight fractionation of the urethane acrylate solution (M-5) was carried out with an eluent of tetrahydrofuran (THF).
• THF tetrahydrofuran
• Microgel (polymer particles R-1): 2.640 parts Distilled water: 2.425 parts
• the method for preparing the above microgel is as follows.
• microgels Preparation of microgels -
• the oil phase components and aqueous phase components listed below were mixed and emulsified for 10 minutes using a homogenizer at 12,000 rpm (revolutions per minute).
• the resulting emulsion was stirred at 45°C for 4 hours, after which 5.20 g of a 10% by mass aqueous solution of 1,8-diazabicyclo[5.4.0]undec-7-ene-octylate (U-CAT SA102, manufactured by San-Apro Co., Ltd.) was added, stirred at room temperature for 30 minutes, and allowed to stand at 45°C for 24 hours.
• the solid content was adjusted to 20% by mass with distilled water, and an aqueous dispersion of a microgel was obtained.
• the average particle size was measured by a light scattering method and found to be 0.20 ⁇ m.
• aqueous phase component 47.2 g of distilled water was prepared.
• aqueous phase components were added to the oil phase components and mixed, and the resulting mixture was emulsified using a homogenizer at 12,000 rpm for 16 minutes to obtain an emulsion.
• To the resulting emulsion was added 16.8 g of distilled water, and the resulting liquid was stirred at room temperature for 10 minutes. Next, the liquid after stirring was heated to 45°C, and stirred for 4 hours while maintaining the liquid temperature at 45°C, thereby distilling off ethyl acetate from the liquid.
• the median diameter of the polymer particles R-3 was 150 nm, and the variation coefficient was 23%. Furthermore, when the dispersibility of the polymer particles R-3 was confirmed by the method already described, it was found that the resin particles R-3 were particles having dispersibility in water and dispersibility in organic solvents.
• P-1 Polyvinyl alcohol, S-LEC BX-5Z manufactured by Sekisui Chemical Co., Ltd.
• P-2 Polyvinyl alcohol, S-LEC BL10 manufactured by Sekisui Chemical Co., Ltd.
• P-3 Resin synthesized by the following synthesis method
• Blenmer PME-100 methoxydiethylene glycol monomethacrylate, manufactured by Nippon Oil & Fats Co., Ltd
• the binder polymer P-3 thus obtained had a solid content of 23% by mass and a weight average molecular weight of 35,000 in terms of polystyrene measured by GPC.
• Anionic surfactant (A-1) Compound shown below Fluorine-based surfactant (W-1): Compound shown below Surfactant (W-2): Compound shown below Surfactant (W-2) is a compound described in International Patent No. 2024-117242.
• the 62 cm x 40 cm planographic printing plate precursor was passed through nip rolls 50 times, and then 30 sheets of slip paper and planographic printing plate precursor were stacked alternately, and 62 cm x 40 cm x 0.65 mm protective materials (pads: moisture content 10% by mass) were further stacked on top and bottom, and packaged in aluminum craft paper.
• the above-mentioned packages were left to stand in a 50°C environment for 20 days to produce laminates.
• all of the planographic printing plate precursors were stacked with the support side facing down. The following evaluations were performed using the planographic printing plate precursor that was in contact with the uppermost protective material of the obtained laminate via the slip paper.
• the obtained lithographic printing plate precursor was exposed using a Luxel (registered trademark) PLATESETTER T-6000III equipped with an infrared semiconductor laser manufactured by Fujifilm Corporation under the conditions of an outer drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,400 dpi (dots per inch).
• the exposed images included a solid image, a fine line image (a test chart in which the thickness of the fine lines (fine line-shaped image areas in non-image areas) was changed at 2 ⁇ m intervals from 4 ⁇ m to 30 ⁇ m), and a 50% halftone dot chart of a 20 ⁇ m dot FM screen.
• the moisture content (equilibrium moisture content) of the protective material was measured by the method according to JIS P 8202.
• the exposed original plate thus obtained was attached to the plate cylinder of a printing machine LITHRONE26 manufactured by Komori Corporation without being developed.
• dampening solution of Ecology-2 manufactured by Fujifilm Corporation
• tap water 2/98 (volume ratio)
• Values-G(N) black ink manufactured by DIC Corporation
• dampening solution and ink were supplied by the standard automatic printing start method of LITHRONE26 to perform on-press development, and then 100 sheets of Tokubishi Art paper (manufactured by Mitsubishi Paper Mills, ream weight: 76.5 kg) were printed at a printing speed of 10,000 sheets per hour.
• the evaluation criteria were as follows.
• Non-image area has stains of 30% or more: D
• the obtained lithographic printing plate precursor was exposed using a Luxel PLATESETTER T-6000III equipped with an infrared semiconductor laser manufactured by Fujifilm Corp. under the conditions of an outer drum rotation speed of 1,000 rpm, a laser output of 70%, and a resolution of 2,400 dpi.
• the exposed image included a solid image and a 50% halftone dot chart of a 20 ⁇ m dot FM (Frequency Modulation) screen.
• the exposed lithographic printing plate precursor thus obtained was attached, without being developed, to the plate cylinder of a printing machine LITHRONE26 manufactured by Komori Corporation.
• dampening solution and ink were supplied by the standard automatic printing start method of LITHRONE26 to perform on-press development, and then 100 sheets of Tokubishi Art paper (ream weight: 76.5 kg, manufactured by Mitsubishi Paper Mills, Ltd.) were printed at a printing speed of 10,000 sheets per hour. Furthermore, printing was continued, and printing durability was evaluated based on the number of printed sheets at which it was visually recognized that the density of the solid image began to become thin. The higher the number of printed sheets, the better the printing durability.
• the obtained lithographic printing plate precursors were conditioned for 1 hour in an environment of 25°C and 80% RH, and then laminated with 30 sheets of interleaving paper and packaged in aluminum-deposited craft. To prevent outside air from entering, gaps were completely sealed with packing tape to create a sealed state. The packaged plates were then left to stand for 4 days in a thermostatic chamber set at 50°C. After being removed from the thermostatic chamber and cooled to room temperature (25°C), the package was opened, and the center (15th) lithographic printing plate precursor was used to evaluate on-machine developability over time based on the following evaluation criteria.
• the planographic printing plate precursor prepared as described above was exposed (equivalent to irradiation energy of 110 mJ/cm2) using a Kodak Magnus 800 Quantum equipped with an infrared semiconductor laser under the conditions of output of 27 W, outer drum rotation speed of 450 rpm, and resolution of 2,400 dpi (dots per inch, 1 inch is 2.54 cm).
• the exposed image included a solid image and an AM screen (Amplitude Modulation Screen) 50% dot chart.
• the exposed plate precursor obtained was attached to the cylinder of a Heidelberg SX-74 printing machine of a size of 1920 without development processing. A 100 L capacity dampening water circulation tank with a built-in nonwoven fabric filter and temperature control device was connected to this printing machine.
• the number of sheets of printing paper required until the ink was not transferred to the non-image area was measured as on-press developability. The smaller the number of sheets, the better the on-press developability.
• the exposure was performed in an environment of 25°C and 50% RH.
• the color development of the lithographic printing plate precursor immediately after exposure was measured. The measurement was performed using a spectrophotometer CM2600d manufactured by Konica Minolta, Inc. and operation software CM-S100W, using the SCE (i.e., regular reflected light excluded) method.
• the color development was evaluated using the L * value (i.e., lightness) of the L * a * b * color system, based on the difference ⁇ L between the L * value of the exposed area and the L * value of the unexposed area. It can be said that the larger the ⁇ L value, the better the color development.
• Example 3-44 The ⁇ L value in Example 3-44 was 11.5, the ⁇ L value in Example 3-45 was 14, and the ⁇ L value in Example 3-46 was 14.
• Example 3-30 in Table 6 is an example in which a specific borate compound (B-18) was used as the electron-donating polymerization initiator, similar to Example 3-15 in Table 5, and
• Example 3-32 in Table 6 is an example in which a specific borate compound (B-6) was used as the electron-donating polymerization initiator, similar to Example 3-5 in Table 3.
• Examples 3-30 and 3-32 unlike Examples 3-5 and 3-16, when two types of electron-accepting polymerization initiators were used in combination, the suppression of development failure over time and the printing durability were improved.
• Example 3-36 a specific borate compound (B-6) was used as an electron-donating polymerization initiator in the same manner as in Example 3-5 in Table 3.
• Example 3-36 unlike Example 3-5, two types of infrared absorbing initiators were used in combination, and the suppression of development failure over time and printing durability were improved. This indicates that it is also preferable to use two or more types of infrared absorbing initiators in combination.
• the results shown in Table 8 indicate that the use of a specific borate compound (an asymmetric borate compound) as an electron-donating polymerization initiator not only improves the suppression of poor development over time, but also improves the developability over time and visibility. This is presumably because the specific borate compound is asymmetric, which causes the HOMO potential to shift into a preferred range.
• the electron-donating polymerization initiators used in Examples 4-1 to 4-11 in Table 9 are specific borate compounds having an anion moiety with an asymmetric structure and an infrared absorbing dye cation as the cation moiety.
• the electron-donating polymerization initiator used in Comparative Example 2-1 is a borate compound having an anion moiety having a symmetric structure and an infrared absorbing dye cation as the cation moiety.
• Table 9 indicate that the specific borate compound having an asymmetric anion moiety and an infrared absorbing dye cation moiety has excellent suppression of development failure over time and printing durability. It was also shown that not only the suppression of development failure over time and printing durability were improved, but also the solvent solubility was improved.
• 12a, 12b aluminum support, 14: undercoat layer, 16: image recording layer, 18: aluminum plate, 20a, 20b: anodized film, 22a, 22b: micropores, 24: large diameter hole, 26: small diameter hole, D: depth of large diameter hole, 610: anodizing treatment device, 612: power supply tank, 614: electrolytic treatment tank, 616: aluminum plate, 618, 26: electrolyte, 620: power supply electrode, 622, 628: roller, 624: nip roller, 630: electrolytic electrode, 632: tank wall, 634: DC power source

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