JP2005053070A - Original plate for lithographic printing plate, and method for lithographic printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for a lithographic printing plate which is excellent in printing plate wear, has high sensitivity and is developable on a printing machine, and a method for lithographic printing. <P>SOLUTION: The original plate for the lithographic printing plate is characterized by having an image forming layer comprising (1) a dye or a pigment with a maximum absorption at 700-1,200 nm, (2) a salt of a carboxylic acid ion and an onium ion, and (3) an ethylenically unsaturated polymerizable compound on an aluminum substrate, developable with an ink or a dampening water, and the substrate having an anodized film with a void volume defined by a specified equation of 20-70% and the diameter of micro-pores exposed on the surface of ≤15 nm on a roughened aluminum or aluminum alloy. The method for lithographic printing comprises a process wherein the original plate is image-exposed with a laser with the wave length of 700-1,200 nm, a process wherein the ink or the dampening water is fed under a condition where the image-exposed original plate is mounted on the printing machine and the image forming layer in an unexposed region is removed, and a process wherein printing is performed by using the lithographic printing plate which has been thus prepared into the printing plate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lithographic printing plate precursor and a lithographic printing method using the same, and more particularly, to a lithographic printing plate precursor having excellent printing durability, high sensitivity and developable on a printing press, and the same. The present invention relates to a lithographic printing method.

In general, a lithographic printing plate is composed of an oleophilic image portion that receives ink in the printing process and a hydrophilic non-image portion that receives dampening water. Conventional lithographic printing plates are made by exposing a non-image area to a PS plate having a lipophilic photosensitive resin layer on a hydrophilic support through a lith film and then dissolving and removing the non-image area with a developer. It was normal to do.
In recent years, computers electronically process, store, and output images as digital information. Therefore, the image forming process corresponding to the digital image information can directly form an image on the lithographic printing original plate without using a lith film by scanning exposure using active radiation having high directivity such as laser light. desirable. A technique for making a printing plate from digital image information without using a lith film is called computer-to-plate (CTP).
If the conventional plate-making method using a PS plate is to be carried out by computer-to-plate (CTP) technology, there is a problem that the wavelength region of the laser beam does not match the photosensitive wavelength region of the photosensitive resin.

Further, in the conventional PS plate, a step (development process) for dissolving and removing the non-image portion after exposure is indispensable. Furthermore, a post-processing step of washing the developed printing plate with water, treating it with a rinsing liquid containing a surfactant, or treating with a desensitizing liquid containing gum arabic or starch derivatives is also necessary. The point that these additional wet treatments are indispensable is a big problem for the conventional PS plate. Even if the first half (image forming process) of the plate making process is simplified by the digital processing, the effect of the simplification is insufficient in the wet process where the second half (development process) is complicated.
Particularly in recent years, consideration for the global environment has become a major concern for the entire industry. In consideration of the environment, it is desirable to simplify the wet post-treatment or change to a dry treatment.

One of the methods to eliminate the processing process is to remove the non-image area of the printing original plate by attaching the exposed printing original plate to the cylinder of the printing press and supplying dampening water and ink while rotating the cylinder. There is a method called top development. That is, after the printing original plate is exposed, it is mounted on a printing machine as it is, and the processing is completed in a normal printing process.
Such a lithographic printing plate suitable for on-press development has a photosensitive layer soluble in dampening water or an ink solvent, and is suitable for development on a printing press placed in a bright room. It is required to have room handling properties.
In the conventional PS plate, it is practically impossible to satisfy such a requirement.

There has been proposed a lithographic printing original plate in which a photosensitive layer in which thermoplastic hydrophobic polymer fine particles are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support (see, for example, Patent Document 1). In the plate making, exposure is performed with an infrared laser, and the thermoplastic hydrophobic polymer fine particles are coalesced (fused) with heat generated by photothermal conversion to form an image. On-press development can be performed by supplying at least one of water and ink. This lithographic printing original plate has handleability in a bright room because the photosensitive region is an infrared region.
However, an image formed by coalescence (fusion) of thermoplastic hydrophobic polymer fine particles has insufficient strength and has a problem in printing durability as a printing plate.

A lithographic printing original plate including microcapsules encapsulating a polymerizable compound in place of the thermoplastic fine particles has been proposed (see, for example, Patent Documents 2 to 7). The polymer image formed by the reaction of the polymerizable compound is superior in strength to the image formed by fusing fine particles.
Since a polymerizable compound has high reactivity, many methods for isolating it using microcapsules have been proposed (see, for example, Patent Documents 2 to 7). A thermally decomposable polymer is used for the shell of the microcapsule.

Japanese Patent No. 2938397 JP 2000-2111262 A JP 2001-277740 A JP 2002-29162 A JP 2002-46361 A JP 2002-137562 A JP 2002-326470 A

However, the lithographic printing original plates described in Patent Documents 2 to 7 have not had sufficient printing durability.
An object of the present invention is to provide a lithographic printing plate precursor and a lithographic printing method which have excellent printing durability, high sensitivity and can be developed on a printing press.

  The present invention provides a lithographic printing plate precursor [1] below and a lithographic printing method [2] below.

[1] A lithographic printing plate precursor that can be developed on-press with an ink having an image forming layer containing the following components (1) to (3) and / or a dampening solution on an aluminum support, The aluminum support has a porosity of 20 to 70% defined by the following formula (A) on the roughened aluminum or aluminum alloy, and the diameter of the micropores exposed on the surface is 15 nm. A lithographic printing plate precursor comprising an anodic oxide film as described below.

(1) Dye or pigment having maximum absorption at 700 to 1200 nm (2) Salt of carboxylate ion and onium ion (3) Ethylenically unsaturated polymerizable compound

Porosity (%) = [1- (oxide film density / 3.98)] × 100 (A) formula

[Oxide film density (g / cm ³ )
= Oxide film weight per unit area / oxide film thickness]

[2] A step of image-exposing the lithographic printing plate precursor as described in (1) above using a laser having a wavelength of 700 to 1,200 nm; A lithographic printing method comprising a step of supplying at least one of water and removing an image forming layer in an unexposed area and making a plate, and a step of printing using the lithographic printing plate made.

The lithographic printing plate precursor according to the present invention uses an aluminum support having an anodized film having a specific porosity and a specific size of micropores, thereby improving the heat insulating effect of the support. Accordingly, the printing durability was improved, and the developability on the printing press could be maintained well.
Furthermore, it has been found that by using a salt of a carboxylate ion and an onium ion in the present invention as a polymerization initiator, particularly high sensitivity and printing durability can be obtained, and the on-press developability is also excellent.

  The lithographic printing plate precursor of the present invention comprises (1) a dye or pigment having a maximum absorption at 700 to 1200 nm on an aluminum support having an anodized film having a specific porosity and a micropore of a specific size. (2) By having an image forming layer containing a salt of carboxylate ion and onium ion and (3) an ethylenically unsaturated polymerizable compound, the heat insulating effect of the support is improved, and accordingly the image forming layer Curing was improved, printing durability was improved, and developability on the printing press could be maintained well.

The lithographic printing plate precursor and the lithographic printing method of the present invention will be described in detail below.
The lithographic printing plate precursor of the present invention comprises, on an aluminum support, (1) a dye or pigment having a maximum absorption at 700 to 1200 nm, (2) a salt of carboxylate ion and onium ion, and (3) an ethylenic non-reactive material. An aluminum support that has an image-forming layer containing a saturated polymerizable compound and is the most important requirement in the lithographic printing plate precursor according to the invention will be described first.

  The aluminum support used in the lithographic printing plate precursor of the present invention has a porosity defined by the following formula (A) on the roughened aluminum or aluminum alloy in the range of 20 to 70%, and The micropores exposed on the surface have an anodized film having a diameter of 15 nm or less.

Porosity (%) = [1- (oxide film density / 3.98)] × 100 (A) formula

[Oxide film density (g / cm ³ )
= Oxide film weight per unit area / oxide film thickness]

As the aluminum support used in the lithographic printing plate precursor of the present invention, a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic on which aluminum (alloy) is laminated or deposited A film or paper is preferably selected. Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 may be used.
As a method for producing the aluminum plate, a DC casting method, a method in which soaking and / or annealing treatment is omitted from the DC casting method, and a continuous casting method can be used.

In the following description, the above-described support made of aluminum or an aluminum alloy is generically used as an aluminum support (in this specification, also referred to as an aluminum support for a lithographic printing plate or simply a support). Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is 10% by weight or less. In the present invention, a pure aluminum plate is suitable. However, since pure aluminum is difficult to manufacture in terms of refining technology, it may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and it is a conventionally publicly known material described in Aluminum Handbook 4th Edition (1990, published by Light Metal Association), for example, JIS A 1050, JIS A 1100, JIS A 3103, JIS A 3005, etc. can be used as appropriate.
Moreover, the thickness of the aluminum support body used for this invention is about 0.1-0.6 mm. This thickness can be changed as appropriate according to the size of the printing press, the size of the printing plate, and the desire of the user.

<< Method for producing aluminum support for lithographic printing plate >>
In general, an aluminum support for a lithographic printing plate has a degreasing process for removing rolling oil adhering to the aluminum plate, a desmutting process for dissolving the smut on the surface of the aluminum plate, and a roughening for roughening the surface of the aluminum plate. It is manufactured through a treatment step, an anodization treatment step of covering the surface of the aluminum plate with an oxide film, and the like.
In order to provide an aluminum support with an anodized film having the porosity and surface pore diameter defined by the above formula (A) within the above ranges, the method for producing a support of the present invention is particularly effective in an acidic aqueous solution. A surface roughening treatment step (also referred to as an electrochemical surface roughening treatment step) for electrochemically roughening the aluminum plate using an alternating current, and the electricity quantity during anode of the aluminum plate (Q _A ) It is preferable to include an electrochemical surface roughening treatment step in which the ratio (Q _C / Q _A ) between the quantity of electricity and cathode electricity (Q _C ) is 0.5 to 2.0.

Here, the method for producing a support of the present invention may include a surface treatment step of an aluminum plate combined with mechanical roughening treatment, chemical etching treatment in an acid or alkaline aqueous solution, or the like. And although the manufacturing method including the electrochemical roughening process process of this invention may be a continuous method or an intermittent method, it is preferable to use a continuous method industrially.
As described above, a support having undergone an electrochemical surface roughening treatment process (which may be combined with a surface treatment process if necessary) is subjected to an anodizing treatment step to form a hydrophilic film having a specific thermal conductivity. (Anodized film) is provided. Further, after the anodizing treatment step, an acid treatment step, an alkali treatment step, a sealing treatment step, or a hydrophilization treatment step may be performed as necessary.
The lithographic printing plate precursor support preferably produced as described above may be provided with an undercoat layer after formation.

<Electrochemical roughening process>
First, the electrochemical surface roughening process in the present invention will be described.
The electrochemical surface roughening treatment step is a step of electrochemically roughening the surface of the aluminum plate through an alternating current using an aluminum plate as an electrode in an acidic aqueous solution. Is different. In the present invention, in the electrochemical surface roughening treatment, the quantity of electricity when the aluminum plate becomes the anode, that is, the quantity of electricity Q _A during anode, and the quantity of electricity when the aluminum plate becomes the cathode, ie, quantity of electricity Q _C at cathode. By making the ratio Q _C / Q _A in the range of 0.5 to 2.0, uniform honeycomb pits can be generated on the surface of the aluminum plate. When Q _C / Q _A is less than 0.5, non-uniform honeycomb pits are likely to be formed, and even when 2.0 / 2.0 is exceeded, non-uniform honeycomb pits are likely to be formed. Further, the Q _C / Q _A is preferably in the range of 0.8 to 1.5.

Examples of the alternating current waveform used in the electrochemical roughening treatment step include a sine wave, a rectangular wave, a triangular wave, and a trapezoidal wave. Among these, a rectangular wave or a trapezoidal wave is preferable.
Moreover, as a frequency of the said alternating current, 30-200 Hz is preferable from a viewpoint of the cost which manufactures a power supply device, and it is more preferable that it is 40-120 Hz. An example of a trapezoidal wave preferably used in the present invention is shown in FIG. In FIG. 1, the vertical axis indicates the current value, the horizontal axis indicates time, ta is the anode reaction time, tc is the cathode reaction time, tp and tp ′ are the time until the current value reaches the peak from 0, and Ia is the anode cycle. The peak current on the side and Ic indicate the peak current on the cathode cycle side. When a trapezoidal wave is used as the waveform of the alternating current, the time tp and tp ′ until the current reaches a peak from 0 is preferably 0.1 to 2 msec, and more preferably 0.3 to 1.5 msec. If the times tp and tp ′ are less than 0.1 msec, the impedance of the power supply circuit influences, a large power supply voltage is required at the time of rising of the current waveform, and the equipment cost of the power supply increases. If the times tp and tp ′ exceed 2 msec, the influence of trace components in the acidic aqueous solution increases, and it becomes difficult to perform a uniform roughening treatment.

  Further, the duty of the alternating current used in the electrochemical surface roughening treatment step is preferably in the range of 0.25 to 0.5 from the point of uniformly roughening the aluminum plate surface, More preferably, it is within the range of -0.4. The duty in the present invention refers to ta / T, where ta is the time during which the anode reaction of the aluminum plate continues in the period T of the alternating current (anode reaction time). In particular, on the surface of the aluminum plate during the cathode reaction, in addition to the formation of smut components mainly composed of aluminum hydroxide, dissolution and destruction of the oxide film occurred, and the start of the pitting reaction during the anode reaction of the next aluminum plate Therefore, the selection of the duty of the alternating current has a great effect on uniform roughening.

The current density of the alternating current is a trapezoidal wave or rectangular wave peak value, and is preferably 10 to 200 A / dm ² for both the anode cycle side Ia and the cathode cycle side Ic of the alternating current. Ic / Ia is preferably in the range of 0.9 to 1.5. In electrochemical graining treatment step, the total amount of electricity furnished to anode reaction of the aluminum plate at the time the electrochemical graining is completed, 50~800C / dm ² is preferred.

As the acidic aqueous solution used in the present invention, those used for electrochemical surface roughening treatment using a normal direct current or alternating current can be used, and among them, an acidic aqueous solution mainly composed of nitric acid is preferably used. Here, “mainly” in the present invention means that the main component in the aqueous solution is 30% by mass or more, preferably 50% by mass or more based on the entire component. Hereinafter, the same applies to other components.
As the acidic aqueous solution mainly composed of nitric acid, those used for electrochemical surface roughening treatment using a normal direct current or alternating current as described above can be used. For example, aluminum nitrate, sodium nitrate, ammonium nitrate, etc. One or more of the nitric acid compounds can be used by adding to a nitric acid aqueous solution having a nitric acid concentration of 5 to 15 g / l until reaching saturation from 0.01 g / l. In the acidic aqueous solution mainly composed of nitric acid, a metal contained in an aluminum alloy such as iron, copper, manganese, nickel, titanium, magnesium, or silicon may be dissolved.
The acidic aqueous solution mainly composed of nitric acid contains nitric acid, an aluminum salt, and nitrate, and contains 1 to 15 g / l, preferably 1 to 10 g / l of aluminum ions, and 10 to 300 ppm of ammonium ions. Thus, it is preferable to use a solution obtained by adding aluminum nitrate and ammonium nitrate to a nitric acid aqueous solution having a nitric acid concentration of 5 to 15 g / l. The aluminum ions and ammonium ions increase spontaneously during the electrochemical surface roughening treatment. Moreover, 10-95 degreeC is preferable and the liquid temperature in this case has more preferable 40-80 degreeC.

  As the electrolysis apparatus used in the surface roughening treatment step, known electrolysis apparatuses such as a vertical type, a flat type, and a radial type can be used, and a radial type electrolysis apparatus as described in JP-A-5-195300 is used. Particularly preferred. FIG. 2 is a schematic diagram of a radial electrolyzer used in the present invention. In FIG. 2, the radial electrolysis apparatus includes an aluminum plate 11 wound around a radial drum roller 12 disposed in a main electrolytic tank 40, and electrolytic treatment is performed by main poles 13 a and 13 b connected to an AC power source 20 in the conveyance process. Is done. The acidic aqueous solution 14 is supplied from the acidic aqueous solution supply port 15 through the slit 16 to the acidic aqueous solution slit 17 between the radial drum roller 12 and the main poles 13a and 13b. Next, the aluminum plate 11 treated in the main electrolytic cell 40 is subjected to electrolytic treatment in the auxiliary anode cell 50. The auxiliary anode 18 is disposed opposite to the aluminum plate 11 in the auxiliary anode tank 50, and the acidic aqueous solution 14 is supplied so as to flow between the auxiliary anode 18 and the aluminum plate 11. The auxiliary anode 18 can be selected from known oxygen generating electrodes such as ferrite, iridium oxide, platinum, or platinum clad or plated on a valve metal such as titanium, niobium, or zirconium. The main electrodes 13a and 13b can be selected from carbon, platinum, titanium, niobium, zirconium, and electrodes used for stainless steel and fuel cell cathodes, with carbon being particularly preferred. As the carbon, commercially available impervious graphite for chemical equipment, resin cored graphite, and the like can be used.

The supply direction of the acidic aqueous solution passing through the main electrolytic cell 40 and the auxiliary anode cell 50 may be parallel to the progress of the aluminum plate 11 or a counter. The relative flow rate of the acidic aqueous solution with respect to the aluminum plate is preferably 10 to 1000 cm / sec.
One electrolysis apparatus can be connected to one or more AC power supplies. Two or more electrolysis devices may be used, and electrolysis conditions in each device may be the same or different.
In addition, after the electrolytic treatment is completed, it is preferable to perform liquid draining with a nip roller and water washing by spraying so as not to take the treatment liquid to the next step.

  Furthermore, in the electrochemical surface roughening treatment, nitric acid and water are used in proportion to the amount of current supplied to the acidic aqueous solution in which the aluminum plate in the electrolysis apparatus undergoes anodic reaction, for example, (i) the conductivity of the acidic aqueous solution and (ii ) Based on the concentration of nitric acid and aluminum ions determined from the propagation velocity of ultrasonic waves and (iii) temperature, add the nitric acid and water while adjusting the amount of nitric acid and water. It is preferable to keep the concentration of the acidic aqueous solution constant by sequentially discharging the acidic aqueous solution from the electrolytic apparatus and discharging it.

  Next, the surface treatment process including mechanical surface roughening treatment, chemical etching treatment in acid or alkaline aqueous solution, desmut treatment, etc. will be described in order. Such a surface treatment step is performed in addition to the above-described electrochemical surface roughening treatment step and an anodizing step which will be described in detail later. ) Or after the electrochemical surface roughening treatment step and before the anodization treatment step (second treatment step). However, each processing process shown below is an illustration as a specific example of a surface treatment process, and is not limited to the content of the following each process. Further, the following treatments in the surface treatment process are optionally performed.

<Surface treatment process>
(Mechanical roughening treatment)
The mechanical roughening treatment in the present invention is a treatment for mechanically roughening the surface of the aluminum plate using a brush or the like, and is preferably performed in the first treatment step.
As the mechanical roughening treatment, it is preferable to treat with a rotating nylon brush roll having a bristle diameter of 0.07 to 0.57 mm and an abrasive slurry liquid supplied to the aluminum plate surface. As the abrasive used in the mechanical surface-roughening treatment step, known materials can be used. Silica sand, quartz, hydroxide described in JP-A-6-135175 and JP-B-50-40047 are used. Preference is given to using aluminum or mixtures thereof.

  As said slurry liquid, what has a specific gravity exists in the range of 1.05-1.3 is preferable. Examples of the method for supplying the slurry liquid to the surface of the aluminum plate include a method for spraying the slurry liquid, a method for using a wire brush, and a method for transferring the surface shape of the uneven roll to the aluminum plate. Further, the methods described in JP-A-55-074898, JP-A-61-162351, JP-A-63-104889, etc. may be used. Further, as described in JP-A-9-509108, an aluminum plate in an aqueous slurry comprising a mixture of particles made of alumina and quartz at a mass ratio in the range of 95: 5 to 5:95. A method of brush polishing the surface can also be used. The average particle size of the mixture at this time is preferably in the range of 1 to 40 μm, particularly 1 to 20 μm.

The nylon brush preferably has a low water absorption rate. For example, nylon bristle 200T manufactured by Toray Industries, Inc. (6,10-nylon, softening point: 180 ° C., melting point: 212 to 214 ° C., specific gravity: 1.08 to 1.09, moisture content: 1.4 to 1.8 at 20 ° C. and 65% relative humidity, 2.2 to 2.8 at 20 ° C. and 100% relative humidity, dry tensile strength: 4.5 to 6 g / d , Dry tensile elongation: 20-35%, boiling water shrinkage: 1-4%, dry tensile resistance: 39-45 g / d, Young's modulus (dry): 380-440 kg / mm ² ).

(Chemical etching treatment in alkaline aqueous solution (alkali etching treatment))
The alkali etching treatment referred to in the present invention refers to a treatment for chemically etching the surface of an aluminum plate in an alkaline aqueous solution, and is preferably performed in each of the first treatment step and the second treatment step. The concentration of the alkaline aqueous solution is preferably 1 to 30% by mass, and the alkaline aqueous solution may contain 0.5 to 10% by mass of an alloy component contained in the aluminum plate as well as aluminum.
As the alkaline aqueous solution, an aqueous solution mainly containing sodium hydroxide (caustic soda) is particularly preferable.

The alkali etching treatment is preferably performed for 1 to 120 seconds at a liquid temperature of the aqueous alkali solution of from room temperature to 95 ° C. When mixing a chemical etching solution in an alkaline aqueous solution first, it is preferable to prepare a treatment solution using liquid sodium hydroxide (caustic soda) and sodium aluminate (sodium aluminate).
In addition, after the alkali etching process is completed, it is preferable to perform liquid draining with a nip roller and water washing with a spray so as not to take the processing liquid to the next step.

(Etching treatment in acid aqueous solution (acidic etching treatment))
The acidic etching treatment referred to in the present invention refers to a treatment for chemically etching an aluminum plate in an acidic aqueous solution, which is preferably performed in the second treatment step, and is preferably performed after the alkali etching treatment. When the acidic etching treatment is performed on the aluminum plate after the alkaline etching treatment, the intermetallic compound containing silica or simple substance Si on the surface of the aluminum plate can be removed, and is generated in the subsequent anodizing treatment step. It is possible to eliminate defects in the anodized film.

  As the acid that can be used for the acidic etching treatment, phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid containing two or more of these acids can be used, and a sulfuric acid aqueous solution is particularly preferable. The concentration of the acidic aqueous solution is preferably 100 to 500 g / l, and the acidic aqueous solution may contain an alloy component contained in the aluminum plate as well as aluminum.

The acidic etching treatment is preferably performed at a liquid temperature of 30 to 90 ° C., preferably 40 to 70 ° C. for 1 to 10 seconds. The amount of dissolution of the aluminum plate at this time is preferably 0.001 to 0.2 g / m ² . The acid concentration, for example, the sulfuric acid concentration and the aluminum concentration are preferably selected from a range that does not crystallize at room temperature. A preferable aluminum ion concentration is 0.1 to 15 g / l, and particularly preferably 5 to 15 g / l.
After the acidic etching treatment is completed, it is preferable to perform liquid drainage by a nip roller and water washing by spraying so as not to take the treatment liquid to the next step.

(Desmutting treatment in acidic solution)
When chemical etching is performed using an aqueous alkali solution, generally smut is generated on the surface of the aluminum plate, so phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid composed of two or more of these acids. It is preferable to perform a so-called desmut treatment in which the smut is dissolved in an acidic solution containing. The desmut treatment is preferably performed as appropriate in the first treatment step and the second treatment step, and more preferably after the alkali etching treatment or the like.
The concentration of the acidic aqueous solution is preferably 1 to 300 g / l. Further, in the acidic aqueous solution, 0.001 to 15 g / l of alloy components contained in the aluminum plate as well as aluminum may be dissolved.

In the desmutting treatment, the liquid temperature of the acidic solution is preferably 20 ° C to 95 ° C, and more preferably 30 to 70 ° C. The treatment time is preferably 1 to 120 seconds, more preferably 2 to 60 seconds.
After the desmut treatment is completed, it is preferable to carry out liquid removal with a nip roller and water washing with a spray so as not to take the treatment liquid to the next step.
In addition, as the desmut treatment liquid (acid solution), it is preferable to use the waste liquid of the acidic aqueous solution used in the electrochemical roughening treatment step in terms of reducing the amount of waste liquid.

As the first treatment step performed before the electrochemical surface roughening treatment step, the mechanical surface roughening treatment on the aluminum plate and / or the dissolution amount of the aluminum plate is 0.01 to 20 g. A desmut treatment in the above acidic solution performed after performing an alkali etching treatment so as to be / m ² can be preferably mentioned.
Further, as a second treatment step after the electrochemical surface roughening treatment step and before the anodizing step described later, 1-10 in an aqueous sulfuric acid solution at 60 to 90 ° C. is applied to the aluminum plate. Acid etching treatment for 2 seconds, or alkali etching treatment for dissolving 0.01 to 5 g / m ² of an aluminum plate in an alkaline aqueous solution, and then desmut treatment in the above acidic solution or sulfuric acid at 60 to 90 ° C. It is preferable to perform an acidic etching treatment in an aqueous solution for 1 to 10 seconds. In addition, when an aluminum plate is subjected to an alkali etching treatment, the above acidic etching is performed under conditions of a liquid temperature of 60 to 90 ° C. and 1 to 10 seconds in order to remove an intermetallic compound containing silica on the surface of the aluminum plate or simple substance Si. It is preferable to apply the treatment. As described above, when the acid etching treatment is performed, defects in the anodized film generated in the subsequent anodizing treatment step can be eliminated. The trouble that adheres can be improved.

<Anodizing process>
On the aluminum support treated as described above, an anodized film is preferably formed by the treatment exemplified below.
The anodizing treatment can be performed by a method conventionally used in this field. Specifically, aluminum is passed by flowing direct current or alternating current to an aluminum support in an aqueous solution or a non-aqueous solution containing at least one selected from sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid and the like. An anodized film can be formed on the surface of the support.
The conditions of the anodizing treatment vary depending on the electrolytic solution used, and thus cannot be determined in general. A range of 5 to 70 A / dm ² , a voltage of 1 to 200 V, and an electrolysis time of 1 to 1000 seconds is preferable.
Among these anodizing treatments, the method of anodizing at a high current density in sulfuric acid described in British Patent No. 1,412,768, and the description in US Pat. No. 3,511,661. A method of anodizing phosphoric acid as an electrolytic bath is preferred. Further, a multi-stage anodizing treatment such as anodizing in sulfuric acid and then anodizing in phosphoric acid can be performed.
In the present invention, it is preferable that the anodic oxide film is 2.0~100g / m ^2, more preferably 3.0~15g / m ^2. More preferably, it is 4.0-10 g / m < ² >.
In the anodized film formed through the anodizing process, fine concave portions called micropores exposed on the surface are uniformly distributed. The porosity (density) of the micropores existing in the anodized film can be adjusted by appropriately selecting the conditions for the anodizing treatment.
And, if necessary, the following pore-wide treatment and sealing treatment are performed on the anodized film, so that the porosity and surface pore diameter of the anodized film are finally defined in the present invention. Within range. The porosity is 20 to 70%, preferably 30 to 60%, and more preferably 40 to 50%. Further, the surface pore diameter is 15 nm or less, preferably 0 to 12 nm, and more preferably 0 to 10 nm.

(Pore wide processing)
In the present invention, for the purpose of increasing the porosity, the treatment (pore wide treatment) may be performed with an acid or alkaline aqueous solution after the anodizing treatment. In this treatment, an aluminum substrate on which an anodized film is formed is immersed in an acid or alkaline aqueous solution, the anodized film is dissolved, and the pore diameter of the micropores is expanded. The pore-wide treatment is preferably performed in the range of 0.01 to 20 g / m ² , more preferably 0.1 to 5 g / m ² , and particularly preferably 0.1 to 4 g / m ² as the dissolution amount of the anodized film. Done.

The following condition ranges are desirable as the pore-wide treatment conditions for dissolving the anodic oxide film. Within this range, good pore-wide processing can be performed.
As a specific condition range, when treating with an acid aqueous solution, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid or phosphoric acid or a mixture thereof, and the concentration is preferably 10 to 1000 g / l, more preferably The temperature is 20 to 500 g / l, preferably 10 to 90 ° C., more preferably 30 to 70 ° C., and the immersion treatment time is preferably 1 to 300 seconds, more preferably 2 to 100 seconds. On the other hand, when treating with an alkaline aqueous solution, it is preferable to use at least one aqueous solution selected from sodium hydroxide, potassium hydroxide, and lithium hydroxide, and the pH of the aqueous solution is preferably 11-13, More preferably, it is 11.5-12.5, As temperature, Preferably it is 10-90 degreeC, More preferably, it is 30-50 degreeC, As immersion treatment time, Preferably it is 1-500 second, More preferably, it is 2- 100 seconds.

(Sealing treatment)
In the present invention, in order to make the micropore diameter of the anodized film a predetermined pore diameter, the following inorganic film can be provided by sputtering, CVD method or the like. Examples of the compound include oxides, nitrides, silicides, and carbides. Moreover, not only a simple substance but a mixture may be sufficient. Specifically: Examples include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, hafnium oxide, vanadium oxide, niobium oxide, tantalum oxide, molybdenum oxide, tungsten oxide, and chromium oxide. In addition, aluminum nitride, silicon nitride, titanium nitride, zirconium nitride, hafnium nitride, vanadium nitride, niobium nitride, tantalum nitride, molybdenum nitride, tungsten nitride, chromium nitride, silicon nitride, Examples thereof include boron nitride. In addition, titanium silicide, zirconium silicide, hafnium silicide, vanadium silicide, niobium silicide, tantalum silicide, molybdenum silicide, tungsten silicide, chromium silicide, and the like can be given. Examples include titanium boride, zirconium boride, hafnium boride, vanadium boride, niobium boride, tantalum boride, molybdenum boride, tungsten boride, and chromium boride. Further, aluminum carbide, silicon carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, molybdenum carbide, tungsten carbide, chromium carbide, and the like can be given.

In the present invention, after providing an anodized film (hydrophilic film), the support is further subjected to a hydrophilic surface treatment by immersing the aluminum support in an aqueous solution containing a hydrophilic compound. (This treatment is also called hydrophilic compound aqueous solution treatment). Suitable hydrophilic compounds include alkali metal silicates, polyvinyl phosphonic acid, potassium zirconium fluoride, phosphate / inorganic fluorine compounds, compounds having sulfonic acid groups, or saccharide compounds. Among them, alkali metal silicate and polyvinyl phosphonic acid are preferable, and alkali metal silicate is most preferable.
The alkali metal silicate aqueous solution treatment is an aqueous solution in which the concentration of the alkali metal silicate is preferably 0.01 to 30% by weight, more preferably 1 to 10% by weight, and the pH at 25 ° C. is 10 to 13. Preferably, it is immersed at 10 to 90 ° C., more preferably 20 to 70 ° C., for 0.5 to 40 seconds, more preferably 1 to 20 seconds.

  As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used, and among them, sodium silicate and potassium silicate are preferable. Examples of the hydroxide used to increase the pH of the alkali metal silicate aqueous solution include sodium hydroxide, potassium hydroxide, lithium hydroxide, and preferably sodium hydroxide and potassium hydroxide are used. . In addition, you may mix | blend alkaline-earth metal salt or a group IVB metal salt with the said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Is mentioned. Examples of Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium titanium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride and the like. be able to. Alkaline earth metals or Group IVB metal salts can be used alone or in combination of two or more.

  The concentration of the polyvinylphosphonic acid aqueous solution is preferably 0.1 to 5% by weight, and more preferably 0.2 to 2.5%. The immersion temperature is preferably 10 to 70 ° C, more preferably 30 to 60 ° C. The immersion time is preferably 1 to 20 seconds.

  The concentration of zirconium fluoride aqueous solution treatment is preferably 0.1 to 10% by weight, more preferably 0.5 to 2% by weight. As for immersion temperature, 30-80 degreeC is preferable. The immersion time is preferably 60 to 180 seconds.

  In the phosphate / inorganic fluorine compound treatment, an aqueous solution of 5 to 20% by weight of a phosphate compound and 0.01 to 1% by weight of an inorganic fluorine compound is preferably used, and the pH is adjusted to 3 to 5. The immersion temperature is preferably 30 to 90 ° C., and the immersion time is preferably 2 to 300 seconds, more preferably 5 to 30 seconds.

  Examples of the phosphate used in the present invention include phosphates of metals such as alkali metals and alkaline earth metals. Specifically, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, potassium dihydrogen phosphate, Dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, disodium hydrogen phosphate Lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate. Examples thereof include sodium phosphite, sodium tripolyphosphate, and sodium pyrophosphate. Preferably, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate can be used.

  Moreover, a metal fluoride is suitable as the inorganic fluorine compound used in the present invention. Specifically, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium hexafluorozirconium, hexafluorozirconium potassium, sodium hexafluorotitanate, potassium hexafluorotitanate, hexafluorozirconium hydrogen acid, hexa Examples thereof include fluorotitanium hydric acid, ammonium hexafluorozirconium, ammonium hexafluorotitanate, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphoric acid phosphoric acid, and ammonium fluorophosphate. In this invention, you may contain 1 type (s) or 2 or more types in an aqueous solution, respectively, and a phosphate and an inorganic fluorine compound.

Compounds having a sulfonic acid group include aromatic sulfonic acids, formaldehyde condensates thereof, derivatives and salts thereof. As aromatic sulfonic acid, phenol sulfonic acid, catechol sulfonic acid, resorcinol sulfonic acid, benzene sulfonic acid, toluene sulfonic acid, lignin sulfonic acid, naphthalene sulfonic acid, acenaphthene-5-sulfonic acid, phenanthrene-2-sulfonic acid, Benzaldehyde-2 (or 3) -sulfonic acid, benzaldehyde-2,4 (or 3,5) -disulfonic acid, oxybenzylsulfonic acids, sulfobenzoic acid, sulfanilic acid, naphthionic acid, taurine and the like are used. Of these, benzenesulfonic acid, naphthalenesulfonic acid, ligninsulfonic acid and their formaldehyde condensates are particularly preferred. Furthermore, you may use as a sulfonate, for example, sodium salt, potassium salt, lithium salt, calcium salt, magnesium salt etc. are mentioned. Among them, an aqueous solution of sodium salt or potassium salt is particularly desirable.
The pH of the aqueous solution containing the compound is preferably 4 to 6.5, and can be adjusted to this pH range with sulfuric acid, sodium hydroxide, ammonia, or the like.
The aqueous solution of the compound having a sulfonic acid group preferably has a concentration of 0.02 to 0.2% by weight, and the immersion temperature is preferably 60 to 100 ° C. The immersion time is preferably 1 to 300 seconds, more preferably 10 to 100 seconds.

The saccharide compounds used in the present invention include monosaccharides and their sugar alcohols, oligosaccharides, polysaccharides and glycosides.
For monosaccharides, trioses and sugar alcohols such as glycerol, tetrose and sugar alcohols such as treose and erythritol, pentoses and sugar alcohols such as arabinose and arabitol, hexoses and sugar alcohols such as glucose and sorbitol, D-glycero -Heptose and sugar alcohols such as D-galactoheptose and D-glycero-D-galactoheptitol, octose such as D-erythro-D-galactoctitol, and nonose such as D-erythro-L-gluco-nonulose Can be mentioned. Examples of oligosaccharides include disaccharides such as saccharose, trehalose, and lactose, and trisaccharides such as raffinose. Examples of the polysaccharide include amylose, arabinan, cyclodextrin, and cellulose alginate.

  The glycoside used in the present invention refers to a compound in which a sugar moiety and a non-sugar moiety are bonded via an ether bond or the like. These glycosides can be classified according to the non-sugar moiety, and examples include alkyl glycosides, phenol glycosides, coumarin glycosides, oxycoumarin glycosides, flavonoid glycosides, anthraquinone glycosides, Examples include triterpene glycosides, steroid glycosides, and mustard oil glycosides. Examples of the sugar moiety include monosaccharides, oligosaccharides, and polysaccharides. Monosaccharides include trioses and sugar alcohols such as glycerol, tetrose and sugar alcohols such as treose and erythritol, pentoses and sugar alcohols such as arabinose and arabitol, hexoses and sugar alcohols such as glucose and sorbitol, D-glycero -Heptose and sugar alcohols such as D-galactoheptose and D-glycero-D-galactoheptitol, octose such as D-erythro-D-galactoctitol, and nonose such as D-erythro-L-gluco-nonulose Can be mentioned. Examples of oligosaccharides include disaccharides such as saccharose, trehalose, and lactose, and trisaccharides such as raffinose. Examples of the polysaccharide include amylose, arabinan, cyclodextrin, and cellulose alginate. The sugar moiety is preferably a monosaccharide or an oligosaccharide, more preferably a monosaccharide or a disaccharide. Examples of preferred glycosides include compounds of the following general formula (I).

(In the formula (I), R represents a linear or branched alkyl group, alkenyl group or alkynyl group having 1 to 20 carbon atoms.)

  Examples of the alkyl group having 1 to 20 carbon atoms represented by R in the general formula (I) include methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl. , Tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl group, and the like. These alkyl groups may be linear or branched, and may be cyclic alkyl groups. Examples of the alkenyl group include allyl and 2-butenyl groups. Examples of the alkynyl group include a 1-pentynyl group.

Specific compounds represented by the general formula (I) include, for example, methyl glucoside, ethyl glucoside, propyl glucoside, isopropyl glucoside, butyl glucoside, isobutyl glucoside, n-hexyl glucoside, octyl glucoside, capryl glucoside, decyl glucoside, 2 -Ethylhexyl glucoside, 2-pentylnonyl glucoside, 2-hexyl decyl glucoside, lauryl glucoside, myristyl glucoside, stearyl glucoside, cyclohexyl glucoside, 2-butynyl glucoside. These compounds are glucosides, which are a type of glycoside, in which the hemiacetal hydroxyl group of glucose is linked to other compounds in the form of an ether, and can be obtained by, for example, a known method of reacting glucose with alcohols. . Some of these alkyl glucosides are commercially available under the trade name GLUCOPON from Henkel, Germany, which can be used in the present invention. Other examples of preferred glycosides include saponins, rutin trihydrate, hesperidin methyl chalcone, hesperidin, nalidinyl hydrate, phenol-β-D-glucopyranoside, salicin, 3 ′, 5,7-methoxy-7- Rutinosides can be mentioned.
Furthermore, the concentration of the saccharide compound aqueous solution is preferably 0.5 to 10% by weight, and the immersion temperature is preferably 40 to 70 ° C. The immersion time is preferably 2 to 300 seconds, more preferably 5 to 30 seconds.
After the immersion treatment in these aqueous solutions, all the substrates are washed with water and dried.

  By these hydrophilic compound aqueous solution treatments, printing smearing problems such as ink repellency deterioration occurring in exchange for adhesion improved by pore wide treatment after anodizing treatment are solved. In other words, due to the increase in the pore diameter, there is a phenomenon (degradation of ink repellency) that makes it difficult to remove ink when printing, especially when the printing machine stops, and when the printing plate is restarted after being left on the printing machine. Although there is a problem that tends to occur, when the hydrophilic compound aqueous solution treatment is performed, the above problem is reduced by improving the hydrophilicity of the surface.

  In the present invention, before applying the image forming layer, if necessary, an inorganic undercoat layer such as a water-soluble metal salt such as zinc borate or an organic undercoat layer may be provided.

  Examples of the organic compound used in the organic undercoat layer include carboxymethylcellulose, dextrin, gum arabic, polymers and copolymers having a sulfonic acid group in the side chain, polyacrylic acid, amino acids such as 2-aminoethylphosphonic acid, and the like. Phosphonic acids having a group, optionally substituted phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, etc. Organic phosphoric acid such as phenyl phosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid, organic phosphinic acid such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent Amino acids such as glycine and β-alanine, Amine hydrochloride having a hydroxyl group of the hydrochloride salt of the fine triethanolamine, although selected from yellow dyes, it may be used by mixing two or more.

This organic undercoat layer can be provided by the following method. That is, a solution in which the above organic compound is dissolved in water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is applied on an aluminum plate and dried. A solution of the organic compound having a concentration of 0.005 to 10% by weight can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used.
The coating amount after drying of the organic undercoat layer is preferably ² to 200 mg / m ² , more preferably 5 to 100 mg / m ² . Good printing durability can be obtained within this range.

An organic polymer is used so that the image forming layer is not damaged when the lithographic printing plate precursor is laminated on the side of the aluminum support used for the lithographic printing plate precursor of the present invention on the side where the image forming layer is not provided. A coating layer made of a compound (hereinafter sometimes referred to as “backcoat layer”) may be provided as necessary.
As the main component of the back coat layer, at least one resin selected from the group of saturated copolymerized polyester resins, phenoxy resins, polyvinyl acetal resins, and vinylidene chloride copolymer resins having a glass transition point of 20 ° C. or higher is used. preferable.

  The saturated copolyester resin is composed of a dicarboxylic acid unit and a diol unit. The dicarboxylic acid unit of the polyester used in the present invention includes aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, succinic acid, and suberic acid , Saturated aliphatic dicarboxylic acids such as sebacic acid, malonic acid, and 1,4-cyclohexanedicarboxylic acid.

The back coat layer further includes a dye or pigment for coloring, a silane coupling agent, a diazo resin composed of a diazonium salt, an organic phosphonic acid, an organic phosphoric acid, and a dye for improving adhesion to the support of the present invention. A cationic polymer or the like, and waxes generally used as slipping agents, higher fatty acids, higher fatty acid amides, silicone compounds composed of dimethylsiloxane, modified dimethylsiloxane, polyethylene powder, and the like may be added as appropriate.
The thickness of the back coat layer is basically in the range of 0.01 to 8 [mu] m, as long as it has a thickness that does not easily damage the image forming layer described later, even if there is no interleaf. When the thickness is less than 0.01 μm, it is difficult to prevent the image forming layer from being scratched when the lithographic printing plate precursors are handled in layers. On the other hand, if the thickness exceeds 8 μm, the backcoat layer may swell and vary in thickness due to chemicals used around the lithographic printing plate precursor during printing, thereby changing the printing pressure and deteriorating printing characteristics. .

Various methods can be applied to coat the back coat layer on the back surface of the support of the lithographic printing plate precursor of the present invention. For example, the above-mentioned components for the back coat layer are dissolved in an appropriate solvent and applied as a solution, or an emulsified dispersion is applied and dried, or a pre-formed film is formed with an adhesive or heat. Examples of the method of bonding to the support of the invention and a method of forming a melt film with a melt extruder and bonding to the support of the present invention are the most preferable for securing the above coating amount. In this method, the back coat component is dissolved in an appropriate solvent to form a solution, which is applied and dried. As the solvent used here, an organic solvent described in JP-A-62-251739 can be used alone or in combination.
In the production of a lithographic printing plate precursor, either the back-coat layer on the back surface or the image-forming layer on the front surface may be applied on the support first, or both may be applied simultaneously.

Next, the image forming layer of the lithographic printing plate precursor according to the invention will be described.
The image forming layer of the lithographic printing plate precursor according to the invention comprises (1) a dye or pigment having a maximum absorption at 700 to 1200 nm, (2) a salt of carboxylate ion and onium ion, and (3) ethylenic unsaturation. A polymerizable compound is included.
Hereinafter, (1) a dye or pigment having a maximum absorption at 700 to 1200 nm, (2) a salt of carboxylate ion and onium ion, and (3) ethylene contained in the image forming layer of the lithographic printing plate precursor of the present invention The unsaturated unsaturated polymerizable compound acid will be described in detail.

(1) a dye or pigment having a maximum absorption at 700 to 1200 nm,
As the dye having the maximum absorption at 700 to 1200 nm, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, naphthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, (thio) pyrylium salts And dyes such as metal thiolate complexes, indoaniline metal complex dyes, oxonol dyes, diimonium dyes, aminium dyes, croconium dyes, and intermolecular CT dyes.

  Examples of preferable dyes include cyanine dyes described in, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, and the like. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, JP-A-58-112793, JP-A-58- Naphthoquinone dyes described in JP-A-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. Examples include squarylium dyes described in JP-A-58-112792, and cyanine dyes described in British Patent 434,875.

  Further, near infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used, and substituted aryl benzoates described in US Pat. No. 3,881,924 are also preferably used. (Thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, JP-A-58-220143 No. 59-41363, No. 59-84248, No. 59-84249, No. 59-146063, No. 59-146061, JP-A 59-216146 Cyanine dyes described in US Pat. No. 4,283,475, pentamethine thiopyrylium salt described in US Pat. No. 4,283,475, etc. Pyrylium compounds disclosed in JP same 5-19702 are also preferably used.

Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).
Particularly preferred among these dyes are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes.

  In particular, a cyanine dye represented by the following general formula (a) is preferable because of excellent photothermal conversion efficiency.

In the general formula (a), R ¹ and R ² each independently represents an alkyl group having 1 to 12 carbon atoms, and an alkoxy group, an aryl group, an amide group, an alkoxycarbonyl group, a hydroxyl group, sulfo group on the alkyl group. The substituent may be selected from a group and a carboxyl group. Y ¹ and Y ² each independently represent oxygen, sulfur, selenium, a dialkylmethylene group or —CH═CH—. Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group, which may have a substituent selected from an alkyl group, an alkoxy group, a halogen atom, and an alkoxycarbonyl group, and is adjacent to Y ¹ and Y ² The aromatic ring may be condensed with two consecutive carbon atoms.

  In the general formula (a), X represents a counter ion necessary for charge neutralization, and is not necessarily required when the dye cation moiety has an anionic substituent. Q represents a polymethine group selected from a trimethine group, a pentamethine group, a heptamethine group, a nonamethine group or an undecamethine group, and is preferably a pentamethine group, a heptamethine group or a nonamethine group from the viewpoint of wavelength suitability and stability for infrared rays used for exposure, It is preferable in terms of stability to have a cyclohexene ring or a cyclopentene ring containing three consecutive methine chains on any carbon.

  In general formula (a), Q is an alkoxy group, aryloxy group, alkylthio group, arylthio group, dialkylamino group, diarylamino group, halogen atom, alkyl group, aralkyl group, cycloalkyl group, aryl group, oxy group, It may be substituted with an iminium base, a group selected from substituents represented by the following general formula (i). Preferred substituents include halogen atoms such as chlorine atoms, diarylamino groups such as diphenylamino groups, phenylthio And arylthio groups such as groups.

In general formula (i), R < ³ > and R < ⁴ > represent a hydrogen atom, a C1-C8 alkyl group, or a C6-C10 aryl group each independently. Y ³ represents an oxygen atom or a sulfur atom.

  Of the cyanine dyes represented by the general formula (a), heptamethine cyanine represented by the following general formulas (a-1) to (a-4) is particularly preferable when exposed to infrared rays having a wavelength of 800 to 840 nm. Mention may be made of pigments.

In general formula (a-1), X ¹ represents a hydrogen atom or a halogen atom. R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the image-forming layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered It is particularly preferable that a ring or a 6-membered ring is formed.

In general formula (a-1), Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Za ⁻ represents a counter anion necessary for charge neutralization, and Za ⁻ is not necessary when the dye has an anionic substituent in the structure and charge neutralization is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, from the storage stability of the image forming layer coating solution. Tetrafluoroborate ion, hexafluorophosphate ion, and sulfonate ion.

In general formula (a-2), R ¹ and R ² each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ¹ and R ² are bonded to each other to form a ring structure. The ring to be formed is preferably a 5-membered ring or a 6-membered ring, and a 5-membered ring is particularly preferable. Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred substituents on the aromatic hydrocarbon group include hydrocarbon groups having 12 or less carbon atoms, halogen atoms, alkoxy groups having 12 or less carbon atoms, alkoxycarbonyl groups, alkylsulfonyl groups, and halogenated groups. An alkyl group etc. are mentioned, An electron withdrawing substituent is especially preferable. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. R ⁹ and R ¹⁰ may be the same or different and each may have a substituent, an aromatic hydrocarbon group having 6 to 10 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a hydrogen atom Alternatively, R ⁹ and R ¹⁰ may be bonded to each other to form a ring having the following structure.

As R < ⁹ > and R < ¹⁰ > in general formula (a-2), aromatic hydrocarbon groups, such as a phenyl group, are the most preferable among the above.
X ⁻ is a counter anion necessary for charge neutralization and has the same definition as Za ⁻ in the general formula (a-1).

In the general formula (a-3), R ^{1 to} R ⁸ , Ar ¹ , Ar ² , Y ¹ , Y ² and X ⁻ have the same meanings as those in the general formula (a-2). Ar ³ represents an aromatic hydrocarbon group such as a phenyl group or a naphthyl group, or a monocyclic or polycyclic heterosphere group containing at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. Naphthothiazole, thianaphtheno-7,6,4,5-thiazole, oxazole, benzoxazole, naphthoxazole, selenazole, benzoselenazole, naphthselenazole, thiazoline, 2-quinoline, 4-quinoline, 1-isoquinoline, 3-isoquinoline, benzimidazole, 3,3-dialkylbenzoindolenine, 2-pyridine, 4-pyridine, 3,3-dialkylbenzo [e] indole , Tetrazole, triazole, pyrimidine, and thiadiazole Heterocyclic group is preferable to be, include the following structures Particularly preferred heterocyclic groups.

In general formula (a-4), R ^{1 to} R ⁸ , Ar ¹ , Ar ² , Y ¹ and Y ² have the same meanings as in general formula (a-2). R ¹¹ and R ¹² may be the same or different and each represents a hydrogen atom, an allyl group, a cyclohexyl group, or an alkyl group having 1 to 8 carbon atoms. Z represents an oxygen atom or a sulfur atom.

  Specific examples of the cyanine dye represented by formula (a) that can be preferably used in the present invention include those exemplified below, and paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. And paragraph numbers [0012] to [0038] of JP-A No. 2002-40638 and paragraph numbers [0012] to [0023] of JP-A No. 2002-23360.

  Other dyes include dyes having a plurality of chromophores described in JP-A No. 2001-242613, and polymer compounds described in JP-A No. 2002-97384 and US Pat. No. 6,124,425. A dye having a chromophore linked to a covalent bond, an anionic dye described in US Pat. No. 6,248,893, a dye having a surface orientation group described in JP-A-2001-347765, and the like are preferably used. be able to.

  As pigments having a maximum absorption at 700 to 1200 nm used in the present invention, commercially available pigments and Color Index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technical Association, published in 1977), “Latest Examples thereof include pigments described in "Pigment Application Technology" (CMC Publishing, 1986) and "Printing Ink Technology" CMC Publishing, 1984).

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  These pigments may be used without surface treatment or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. When the particle diameter of the pigment is less than 0.01 μm, it is not preferable from the viewpoint of stability of the dispersion in the image forming layer coating solution, and when it exceeds 10 μm, it is not preferable from the viewpoint of uniformity of the image forming layer.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

In the present invention, the “dye or pigment having a maximum absorption at 700 to 1200 nm” component may be used alone or in combination of two or more.
As the “dye or pigment having maximum absorption at 700 to 1200 nm” in the present invention, a cyanine dye is preferable.
From the viewpoint of sensitivity, the cyanine dye represented by the general formula (a) is more preferable. Among the cyanine dyes represented by the general formula (a), a cyanine dye in which X ¹ is a diarylamino group or X ² -L ¹ is used. Preferably, a cyanine dye having a diarylamino group is more preferable.
A cyanine dye having an electron-withdrawing group or a heavy atom-containing substituent at both indolenine sites is also preferable. For example, those described in JP-A-2002-278057 are preferably used. Most preferably, X ¹ is a diarylamino group and is a cyanine dye having an electron-withdrawing group at both indolenine sites.

(2) Salt of carboxylate ion and onium ion A salt of carboxylate ion and onium ion used in the image forming layer of the lithographic printing plate precursor according to the invention will be described.
In view of the effect of the present invention (particularly ease of decarboxylation reaction), the carboxylic acid constituting the carboxylic acid ion is (1) a carbon atom at the 2-position is an acyl group, a carbamoyl group (including a substituted carbamoyl group) or a cyano group. Carboxylic acid substituted with a group (2-acyl substituted carboxylic acid, 2-carbamoyl substituted carboxylic acid, 2-cyano substituted carboxylic acid), (2) Carboxyl substituted with a plurality of aryl groups at the 2-position carbon atom Classified as acids (2,2'-diaryl-substituted carboxylic acids), (3) carboxylic acids in which nonmetallic atoms other than carbon and hydrogen atoms are directly bonded to the 2-position carbon atom, and (4) other carboxylic acids it can. In the present invention, the carboxylic acids (1), (2) and (3) are preferred.

(1) Carboxylic acid in which the carbon atom at the 2-position is substituted with an acyl group, carbamoyl group or cyano group The carboxylic acid may have a cyclic structure. The cyclic structure may contain an carbonyl group of an acyl group and an amide bond of a (substituted) carbamoyl group.
Examples of the carboxylate ion in which (1) the carbon atom at the 2-position is substituted with an acyl group, a carbamoyl group or a cyano group are shown below.

A101: benzoyl acetate ion A102: 2-benzoylpropionate ion A103: acetoacetate ion A104: cyanoacetate ion A105: 2-cyanocinnamate ion A106: 2-cyanopropionate ion A107: 5- (3,4,5- Trimethyl-6-oxo-8-hydroxy-3,4,5,6-tetrahydroisochromene) carboxylate ion A108: 4- (3-oxo-7,7-dimethylbicyclo [2.2.1] heptane) Carboxylate ion

(2) Carboxylic acid in which the carbon atom at the 2-position is substituted with a plurality of aryl groups The aryl group may have a substituent. The substituent of the aryl group is the same as the substituent of the aromatic group described in the ethylenically unsaturated polymerizable compound.
Examples of the carboxylate ion in which (2) the carbon atom at the 2-position is substituted with a plurality of aryl groups are shown below.

A201: Ethylthiodiphenylacetic acid ion A202: Hydroxydiphenylacetic acid ion A203: Hydroxy (1-naphthyl) phenylacetic acid ion A204: Mercaptodiphenylacetic acid ion A205: Methoxydiphenylacetic acid ion A206: Cyanodiphenylacetic acid ion A207: Triphenylacetic acid ion A208: 3,3,3-trifluoro-2,2-diphenylpropionate ion A209: hydroxybis (p-chlorophenyl) acetate ion A210: hydroxybis (p-tolyl) acetate ion

A211: 2,2-diphenylpropionate ion A212: Hydroxyphenyl (p-nitrophenyl) acetate ion A213: Chlorodiphenylacetate ion A214: 2,2-di (1-naphthyl) propionate ion A215: Tris (4-chlorophenyl) ) Acetate ion A216: 2,2-diphenylbutyrate ion A217: Diphenylacetate ion

(3) Carboxylic acid in which a nonmetallic atom other than a carbon atom and a hydrogen atom is directly bonded to the 2-position carbon atom. O, S, N, Si and P are preferable, and a halogen atom, O, S and N are more preferable.
The carboxylic acid may have a cyclic structure. The cyclic structure may contain nonmetallic atoms other than carbon atoms and hydrogen atoms.
A nonmetallic atom other than a carbon atom and a hydrogen atom may be directly bonded to the carbon atom at the 2-position as a divalent or higher valent substituent (for example, oxo, thio, imino).
The following are examples of (3) carboxylate ions in which nonmetallic atoms other than carbon atoms and hydrogen atoms are directly bonded to the 2-position carbon atom.

A301: Benzoyl formate ion A302: Pyruvate ion A303: p-methoxybenzoyl formate ion A304: Mercaptopyruvate ion A305: 3-methyl-2-oxobutyrate ion A306: 3-o-nitrophenyl-2-oxopropionate ion A307: 3-phenyl-2-oxopropionic acid ion A308: p-chlorobenzoyl formate ion A309: glyoxylate ion A310: 1-naphthoyl formate ion

A311: N-phenylcarbamoyl formate ion A312: 3-indolecarbonyl formate ion A313: 2-oxobutyrate ion A314: p-acetylbenzoylformate ion A315: trifluoropyruvate ion A316: pentafluorobenzoylformate ion A317: 2-oxo Pentanoate ion A318: 3-p-chlorophenyl-2-oxopropionate ion A319: 3,5-dimethoxybenzoyl formate ion A320: Benzenesulfonyl acetate ion

A321: 3,5-bis (trifluoromethyl) benzenesulfonyl acetate ion A322: 2-benzenesulfonylpropionate ion A323: p-methoxybenzenesulfonyl acetate ion A324: butanesulfonyl acetate ion A325: methanesulfonyl acetate ion A326: 1- Naphthalenesulfonyl acetate ion A327: 2- (1,3-dioxolane) carboxylate ion A328: dimethoxyacetate ion A329: methoxyacetate ion A330: 2-phenoxypropionate ion

A331: Diethylphosphonoacetate ion A332: 2-hydroxy-2-phenylpropionate ion A333: 3,3,3-trifluoro-2-phenyl-2-methoxypropionate ion A334: Phenylthioacetate ion A335: Benzylthioacetate ion A336: Acetoxyphenyl acetate ion A337: 2-thiophenecarboxylate ion A338: 1-oxoisoindoline-2-yl acetate ion A339: Anilinoacetate ion A340: 2-acetamidopropionate ion

A341: 2-anilinopropionate ion A342: 2-dimethylaminopropionate ion A343: acetamide acetate ion A344: maleimide acetate ion A345: p-methylanilinoacetate ion A346: p-methoxyanilinoacetate ion A347: 2- (5 -Methylthiophene) carboxylate ion A348: t-butyldiphenylsilylacetate ion A349: phenylselenoacetate ion A350: trifluoroacetoxyphenylacetate ion

A351: p-methylbenzoyl formate ion A352: 2,4,6-trimethylbenzoyl formate ion A353: 4-fluorobenzoyl formate ion A354: o-chlorobenzoyl formate ion A355: 3,5-dichlorobenzoyl formate ion A356: p- Aminobenzoylformate ion A357: 5-indolecarbonylformate ion A358: 3-furancarbonylformate ion A359: 2-thiophenecarbonylformate ion A360: 2-oxo-5- (pyridin-3-yl) -4-pentenecarboxylate ion

A361: Bromopyruvate ion A362: 2-oxobutyrate ion A363: 2-oxopentanoic acid ion A364: Cyclohexanecarbonylformate ion A365: 3-Nitrobenzoylformate ion A366: 3,5-bis (trifluoromethyl) benzoylformate ion A367: trichloropyruvate ion A368: p-hydroxybenzoyl formate ion A369: methylthioacetate ion A370: p-chlorophenylthioacetate ion

A371: Butylphenylaminoacetic acid ion A372: 3- (1,2,3,4-tetrahydroisoquinoline) carboxylate ion A373: 2-benzyloxycarbonylaminopropionic acid ion A374: 2-benzyloxycarbonylamino-3-methylbutyric acid Ion A375: Tritylaminoacetate ion A376: 2- (1-benzyloxycarbonylpyrrolidine) carboxylate ion A377: Nitroacetate ion A378: 2- (2,4,5-trichlorophenoxy) propionate ion A379: Phenoxyacetate ion A380 : 2-naphthyloxyacetate ion

A381: 2-isopropyl-5-methylcyclohexyloxyacetate ion A382: 2-oxolanecarboxylate ion A383: 3,3,3-trichloro-2,2-dihydroxypropionic acid ion A384: maleimidooxyacetate ion A385: 2- (1-methylpyrrole) carboxylate ion A386: 2-pyrrolecarboxylate ion A387: 2- (5-bromofuran) carboxylate ion A388: 4-imidazolecarboxylate ion A389: 2- (5-methoxyindole) carboxylate ion A390: Hydroxyacetate ion

A391: Trichloroacetate ion A392: Perfluorononanoate ion A393: Trifluoroacetate ion A394: 2,4-Dioxotetrahydrothiazol-3-yl acetate ion A395: 2-Chloropropionate ion A396: Chloroacetate ion A397: Per Fluorodecanoic acid ion A398: Bromophenylacetic acid ion A399: Phenylmethoxyacetic acid ion A400: Trifluoromethylphenylmethoxyacetic acid ion

A401: Hydroxyphenyl acetate ion A402: 2- (4-oxo-4H-chromene) carboxylate ion A403: t-butoxycarbonylaminoacetate ion A404: 5- (2-pyrrolidone) carboxylate ion A405: 4- (2- Oxoimidazolidine) carboxylate ion A406: 4- (2-oxotetrahydrothiazole) carboxylate ion A407: p-methylbenzenesulfonyl acetate ion A408: pentafluorobenzenesulfonyl acetate ion A409: p-methoxyphenoxyacetate ion A410: 2- Furan carboxylate ion A411: mercaptoacetic acid

(4) Other carboxylic acids Other carboxylic acids include various fatty acids and aromatic carboxylic acids.
Examples of (4) other carboxylate ions are shown below.

A501: benzoate ion A502: p-toluic acid ion A503: p-anisic acid ion A504: p-butylbenzoic acid ion A505: 2,6-dimethoxybenzoic acid ion A506: 2,4,6-trimethylbenzoic acid ion A507 : P-phenylbenzoate ion A508: p-phenoxybenzoate ion A509: p-benzoylbenzoate ion A510: o-phenylbenzoate ion

A511: m-phenoxybenzoic acid ion A512: m-benzylbenzoic acid ion A513: o-benzylbenzoic acid ion A514: o-benzoylbenzoic acid ion A515: o- (p-chlorobenzoyl) benzoic acid ion A516: o-anilino Benzoic acid ion A517: 3-furancarboxylic acid ion A518: 3- (furan-3-yl) acrylic acid ion A519: 3-thiophenecarboxylic acid ion A520: Indol-3-ylacetic acid ion

A521: 4-indolecarboxylate ion A522: 5-benzimidazolecarboxylate ion A523: 4-pyrazolecarboxylate ion A524: 3-pyridinecarboxylate ion A525: 9- (2,6,6-trimethyl-1-cyclohexenyl) ) -3,7-dimethyl-2,4,6,8-nonatetraenoate ion A526: cyclopropanecarboxylate ion A527: 2-bicyclo [2.2.1] heptanecarboxylate ion A528: pivalate ion A529: 3-butenoate ion A530: 2-ethylbutyrate ion

A531: p-fluorobenzoic acid ion A532: p-chlorobenzoic acid ion A533: p-iodobenzoic acid ion A534: p-bromobenzoic acid ion A535: p-trifluoromethylbenzoic acid ion A536: p-cyanobenzoic acid ion A537: m-anisate ion A538: 2,4,6-trifluorobenzoate ion A539: 3,5-dichlorobenzoate ion A540: pentafluorobenzoate ion

A541: Acetate ion A542: Isobutyrate ion A543: Adamantane-1-yl acetate ion A544: Cyclohexanecarboxylate ion A545: Palmitate ion A546: p-vinylbenzoate ion A547: 2,4-pentadienoate ion A548: Propionic acid Ion A549: 1-naphthoic acid ion A550: pentanoic acid ion

A551: Henicosanoic acid ion A552: 9-anthracenecarboxylate ion A553: 3-indolecarboxylate ion A554: 1- (1,4a-dimethyl-7-isopropyl-1,2,3,4,4a, 4b, 5 6,10,10a-decahydrophenanthrene) carboxylate ion A555: 1-cyclohexenecarboxylate ion A556: 1-bicyclo [2.2.2] octanecarboxylate ion A557: 3-phenylpropiolate ion A558: cyclopentanecarboxyl Acid ion A559: 2,6-dimethylbenzoate ion A560: 5- (1-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexenyl) -3-methyl-2,4-pentadienoic acid ion

A561: p-hydroxybenzoate ion A562: p-hydroxymethylbenzoate ion A563: 2,4,6-tri-butylbenzoate ion A564: p-acetamidobenzoate ion A565: p-acetylbenzoate ion A566: p-aminobenzoate ion A567: p-dimethylaminobenzoate ion A568: 1,4,6-trihydroxybenzoate ion A569: phenylacetate ion A570: p-methylphenylacetate ion

A571: p-methoxyphenylacetic acid ion A572: p-fluorophenylacetic acid ion A573: cinnamic acid ion A574: o-chlorocinnamic acid ion A575: m-trifluoromethylcinnamic acid ion A576: 2,2-bis (hydroxy Methyl) butyrate ion A577: 6-heptenoate ion A578: acrylate ion A579: icosanoate ion A580: 3-methylcyclohexanecarboxylate ion

A581: 4- (1,2-dithiolan-3-yl) butyrate ion A582: 5,5-dimethyl-3-oxo-1-cyclohexylenecarboxylate ion A583: propiolate ion A584: cyclohexylacetate ion A585: 2-naphtho Acid ion A586: 4-fluoro-1-naphthoic acid ion A587: 2-ethoxy-1-naphthoic acid ion A588: 1-hydroxy-2-naphthoic acid ion A589: 3-amino-2-naphthoic acid ion A590: 8- Formyl-1-naphthoate ion

A591: 3,7-dihydroxy-2-naphthoate ion A592: 2-biphenylenecarboxylate ion A593: 9-fluorenecarboxylate ion A594: 1-fluorenecarboxylate ion A595: 4- (9-oxofluorene) carboxylate ion A596: 5-dibenzopyrancarboxylate ion A597: 2-anthraquinonecarboxylate ion A598: 1-pyrenecarboxylate ion A599: 4-indolecarboxylate ion A600: 3- (indol-3-yl) propionate ion

A601: 3- (5-bromoindole) carboxylate ion A602: 5-indolecarboxylate ion A603: thiophen-2-yl acetate ion A604: formate ion A605: 2-ethylpentanoate ion A606: methacrylate ion A607: 12 -Hydroxydodecanoic acid ion A608: 4-hydroxycyclohexanecarboxylic acid ion A609: 3-methoxypropionic acid ion A610: cyclobutanecarboxylic acid ion

A611: 6-nitrohexanoic acid ion A612: phenylcyclopentyl acetate ion A613: 2-phenylpropionic acid ion A614: 7-phenylheptanoic acid ion A615: 2-phenylbutyric acid ion A616: 3-benzoylpropionic acid ion A617: o- Methyl phenylacetate ion A618: o-methoxyphenyl acetate ion A619: o-fluorophenylacetate ion A620: o-bromophenylacetate ion

A621: m-chlorophenylacetic acid ion A622: m-aminophenylacetic acid ion A623: m-nitrophenylacetic acid ion A624: 2,6-difluorophenylacetic acid ion A625: p-chlorophenylacetic acid ion A626: 2,4-dimethylphenylacetic acid ion A627: 2,5-difluorophenylacetic acid ion A628: 2,4,5-trichlorophenylacetic acid ion A629: pentafluorophenylacetic acid ion A630: 3- (3,4,5-trimethoxyphenyl) propionic acid ion

A631: 2-methylcinnamic acid ion A632: o-fluorocinnamic acid ion A633: m-formylcinnamic acid ion A634: 3,4-methylenedioxyphenylacetic acid ion A635: 2-naphthylacetic acid ion A636: 1-naphthylacetic acid Ion A637: p-isopropylbenzoate ion A638: m-methoxybenzoate ion A639: m-fluorobenzoate ion A640: 1,5-dimethylbenzoate ion

A641: 4-hydroxy-3-methoxybenzoate ion A642: 3-amino-4-fluorobenzoate ion A643: 2,4,6-trihydroxybenzoate ion A644: 3,5-dihydroxy-4-methylbenzoic acid Ion A645: Salicylate ion A646: 6-oxoheptanoate ion A647: 4-tert-butylcyclohexanecarboxylate ion A648: 5- (bicyclo [2.2.1] heptan-2-ene) carboxylate ion A649: 5- (6-methylbicyclo [2.2.1] heptan-2-ene) carboxylate ion A650: 1-adamantanecarboxylate ion A651: 2,5-cyclohexadienecarboxylate ion

The onium ion constituting the salt with the carboxylate ion is an ammonium ion, a diazonium ion, a phosphonium ion, an arsonium ion, a stibonium ion, an oxonium ion, a sulfonium ion, a selenonium ion, a stannonium ion, or an iodonium ion. preferable. Ammonium ions, phosphonium ions, sulfonium ions and iodonium ions are more preferred, and sulfonium ions and iodonium ions are most preferred.
The ammonium ion is the following formula (IV), the diazonium ion is the following formula (V), the phosphonium ion is the following formula (VI), the arsonium ion is the following formula (VII), the stibonium ion is the following formula (VIII), and the oxonium ion Is defined by the following formula (X), the sulfonium ion is defined by the following formula (XI), the selenonium ion is defined by the following formula (XII), the stannonium ion is defined by the following formula (XII), and the iodonium ion is defined by the following formula (XIII).

Ammonium ion: (IV) N ⁺ R ₄
Diazonium ion: (V) NN ⁺ R
Phosphonium ion: (VI) P ⁺ R ₄
Arsonium ion: (VII) As ⁺ R ₄
Stivonium ion: (VIII) Sb ⁺ R ₄
Oxonium ion: (IX) O ⁺ R ₃
Sulfonium ion: (X) S ⁺ R ₃
Selenonium ion: (XI) Se ⁺ R ₃
Stannonium ion: (XII) Sn ⁺ R ₃
Iodonium ion: (XIII) I ⁺ R ₂

In each formula, R is a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. A plurality of R contained in one onium group may be different. A plurality of R may combine to form a heterocyclic ring. R is particularly preferably an aromatic group.
Examples of onium ions are shown below.

C1: triphenylsulfonium ion C2: pt-butylphenyldiphenylsulfonium ion C3: bis (p-chlorophenyl) phenylsulfonium ion C4: tris (pt-butylphenyl) sulfonium ion C5: methyldiphenylsulfonium ion C6: diphenyl Iodonium ion C7: bis (pt-pentylphenyl) iodonium ion C8: bis (p-heptanamidophenyl) iodonium ion C9: bis (p-octyloxyphenyl) iodonium ion C10: benzoyloxypyridinium ion

C11: Tributylbenzylammonium ion C12: Tetraphenylphosphonium ion C13: Bis (p-tolyl) phenylsulfonium ion C14: p-methoxyphenyldiphenylsulfonium ion C15: Bis (pt-butylphenyl) iodonium ion C16: Bis (m -Chlorophenyl) iodonium ion C17: p-tolyldiphenylsulfonium ion C18: p-methoxyphenyldiphenylsulfonium ion C19: p-hydroxyphenyldiphenylsulfonium ion C20: tris (p-tolyl) sulfonium ion

C21: tris (p-fluorophenyl) sulfonium ion C22: benzyldiphenylsulfonium ion C23: benzoylthiolanium ion C24: p-octyloxyphenylphenyliodonium ion C25: benzylmethylpiperidinium ion C26: tetrakis (p-chlorophenyl) phosphonium ion C27: p-tolylphenyliodonium ion C28: 2,4,6-trimethylphenyldiphenylsulfonium ion C29: triethylbenzylammonium ion C30: bis (p-hexylphenyl) iodonium ion

C31: Bis (m-trifluorophenyl) iodonium ion C32: Bis (p-pentanamidophenyl) iodonium ion C33: Bis (p-butoxyphenyl) iodonium ion C34: Bis (p-fluorophenyl) iodonium ion C35: p- Butoxyphenylphenyl iodonium ion C36: Bis (p-phthalimidophenyl) iodonium ion C37: Hexylmethylphenylsulfonium ion C38: Tributylsulfonium ion

  There is no restriction | limiting in particular about the combination of a carboxylate ion and onium ion. Below, the example of the salt which consists of carboxylate ion and onium ion is shown. In the following examples, the example number (A) of the carboxylate ion and the example number (C) of the onium ion are cited. For example, A301C1 in (1) means benzoyl formic acid (A301) triphenylsulfonium (C1).

1: A301C1, 2: A302C1, 3: A303C1,
4: A304C1, 5: A305C1, 6: A306C1,
7: A307C2, 8: A308C2, 9: A309C3,
10: A310C3, 11: A311C3, 12: A301C4,
13: A312C4, 14: A313C5, 15: A314C5,
16: A301C6, 17: A302C6, 18: A301C7,
19: A315C7, 20: A316C8, 21: A317C8,
22: A318C9, 23: A319C9, 24: A301C10,
25: A302C11, 26: A301C12, 27: A301C13,
28: A301C3, 29: A320C1, 30: A407C1,
31: A408C1, 32: A325C4, 33: A320C4,

34: A321C4, 35: A322C4, 36: A323C14,
37: A320C15, 38: A324C15, 39: A325C16,
40: A326C16, 41: A101C1, 42: A102C1,
43: A103C1, 44: A104C1, 45: A327C17,
46: A328C17, 47: A329C1, 48: A330C1,
49: A105C1, 50: A331C18, 51: A332C19,
52: A333C1, 53: A334C1, 54: A335C1,
55: A336C1, 56: A409C1, 57: A204C20,
58: A337C20, 59: A338C1, 60: A339C1,
61: A340C1, 62: A341C21, 63: A342C22,
64: A343C23, 65: A344C7, 66: A345C7,

67: A346C24, 68: A347C24, 69: A339C25,
70: A327C15, 71: A348C15, 72: A349C15,
73: A339C26, 74: A350C27, 75: A102C27,
76: A201C1, 77: A202C1, 78: A203C1,
79: A204C1, 80: A205C28, 81: A207C28,
82: A208C28, 83: A209C28, 84: A210C28,
85: A211C28, 86: A201C7, 87: A212C7,
88: A213C7, 89: A201C29, 90: A207C25,
91: A501C6, 92: A502C6, 93: A503C6,
94: A504C6, 95: A505C6, 96: A506C6,
97: A507C6, 98: A508C6, 99: A509C6,

100: A510C6, 101: A511C6, 102: A512C6,
103: A513C6, 104: A514C6, 105: A515C6,
106: A516C6, 107: A385C6, 108: A386C6,
109: A517C6, 110: A387C6, 111: A518C6,
112: A519C6, 113: A388C6, 114: A520C6,
115: A521C6, 116: A389C6, 117: A522C6,
118: A523C6, 119: A524C6, 120: A525C6,
121: A526C6, 122: A527C6, 123: A528C6,
124: A529C6, 125: A530C6, 126: A501C7,
127: A531C7, 128: A532C7, 129: A533C7,
130: A534C7, 131: A535C7, 132: A536C7,

133: A503C7, 134: A537C7, 135: A538C7,
136: A539C7, 137: A540C7, 138: A541C7,
139: A542C7, 140: A390C7, 141: A543C7,
142: A544C7, 143: A391C7, 144: A392C7,
145: A528C7, 146: A545C7, 147: A521C7,
148: A501C30, 149: A502C30, 150: A503C30, 151: A533C30, 152: A546C30, 153: A517C30, 154: A528C30, 155: A534C31, 156: A533C31, 157: A539C31, 158: A547C31, 160: A548C31 A540C15, 161: A535C15, 162: A549C15, 163: A541C15, 164: A393C15, 165: A544C15,

166: A550C15, 167: A390C15, 168: A543C15, 169: A551C15, 170: A542C32, 171: A527C32, 172: A501C32, 173: A552C32, 174: A553C32, 175: A501C33, 177: A531C33, 177: 578 A533C33, 179: A534C33, 180: A535C33,181: A536C33,182: A503C33,183: A537C33,184: A538C33,185: A539C33,186: A540C33,187: A554C33,188: A541C33,189: 33 191: A650C33, 192: A544C33, 193: A391C 3,194: A392C33,195: A528C33,196: A555C34,197: A556C34,198: A557C34,

199: A107C34, 200: A532C35, 201: A533C35, 202: A534C35, 203: A535C35, 204: A536C35, 205: A503C35, 206: A537C35, 207: A538C35, 208: A539C35, 209: A540C35, 210: A651C35 A541C35, 212: A542C35, 213: A527C35, 214: A544C35, 215: A391C35, 216: A392C35, 217: A528C35, 218: A393C36, 219: A558C36, 220: A410C36, 221: A559C36, 222: A552C36, 236: 552 224: A108C36, 225: A394C36, 226: A501C , 227: A502C1, 228: A503C1,
229: A504C1, 230: A505C1, 231: A506C1,

232: A507C1, 233: A508C1, 234: A509C1,
235: A510C1, 236: A511C1, 237: A512C1,
238: A513C1, 239: A514C1, 240: A515C1,
241: A516C1, 242: A540C1, 243: A531C1,
244: A532C1, 245: A533C1, 246: A534C1,
247: A535C1, 248: A536C1, 249: A538C1,
250: A539C1, 251: A561C1, 252: A562C1,
253: A563C1, 254: A564C1, 255: A565C1,
256: A566C1, 257: A567C1, 258: A339C1,
259: A568C1, 260: A569C1, 261: A570C1,
262: A571C1, 263: A572C1, 264: A379C1,

265: A573C1, 266: A574C1, 267: A575C1,
268: A541C1, 269: A545C1, 270: A542C1,
271: A528C1, 272: A390C1, 273: A543C1,
274: A392C1, 275: A576C1, 276: A411C1,
277: A393C1, 278: A395C1, 279: A547C1,
280: A577C1, 281: A578C1, 282: A579C1,
283: A530C1, 284: A610C1, 285: A580C1,
286: A581C1, 287: A582C1, 288: A583C1,
289: A107C1, 290: A501C28, 291: A502C28, 292: A503C28, 293: A504C28, 294: A540C28, 295: A573C28, 296: A583C28, 297: A544C28,

298: A531C2, 299: A527C2, 300: A541C18, 301: A549C18, 302: A540C37, 303: A526C37, 304: A537C37, 305: A548C5, 306: A533C5,
307: A391C38, 308: A382C38, 309: A549C1,
310: A585C1, 311: A586C1, 312: A587C1,
313: A588C1, 314: A589C1, 315: A590C1,
316: A591C1, 317: A592C1, 318: A593C1,
319: A594C1, 320: A595C1, 321: A552C1,
322: A596C1, 323: A597C1, 324: A598C1,
325: A553C1, 326: A599C1, 327: A600C1,
328: A601C1, 329: A602C1, 330: A337C1,
331: A603C1, 332: A519C1, 333: A517C1,
334: A518C1, 335: A410C1, 336: A386C1

Two or more salts of carboxylate ions and onium ions may be used in combination.
The salt of carboxylate ion and onium ion and the synthesis method thereof are described in JP-A Nos. 2001-343742 and 2002-148790.
The salt of carboxylate ion and onium ion has a solubility in water at 25 ° C. of preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more. 30% by mass or more is more preferable, and 40% by mass or more is most preferable. The solubility means the mass (g) of a solute dissolved in 100 g of an aqueous solution.
The image forming layer preferably contains a salt of carboxylate ion and onium ion in the range of 0.1 to 30% by mass, more preferably in the range of 0.5 to 25% by mass. More preferably, it is contained in the range of 5% by mass, and most preferably in the range of 5-15% by mass.

(3) Ethylenically unsaturated polymerizable compound The ethylenically unsaturated polymerizable compound preferably has a plurality of ethylenically unsaturated groups (is bifunctional or more), and has three or more ethylenically unsaturated groups. (Trifunctional or higher) is more preferable, tetrafunctional or higher is more preferable, pentafunctional or higher is still more preferable, and hexafunctional or higher is most preferable.
The ethylenically unsaturated polymerizable compound is preferably represented by the following formula (I).

(I) L ¹ (−CR ¹ = CR ² R ³ ) _m

In the formula (I), L ¹ is an m-valent linking group, R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and m is 2 It is an integer above.
When m is 2, L ¹ is an alkylene group, a substituted alkylene group, an arylene group, a substituted arylene group, a divalent heterocyclic group, —O—, —S—, —NH—, —NR—, —CO—. , —SO—, —SO ₂ —, and combinations thereof are preferable. R is an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group.
The alkylene group and the alkyl group may have a cyclic structure or a branched structure. The number of carbon atoms in the alkylene group and the alkyl group is preferably 1 to 20, more preferably 1 to 15, still more preferably 1 to 10, and most preferably 1 to 8.

Examples of the substituent of the substituted alkylene group and the substituted alkyl group include a halogen atom, an aryl group, a substituted aryl group and an alkoxy group.
The arylene group is preferably phenylene, and most preferably p-phenylene. The aryl group is preferably phenyl.
The divalent heterocyclic group may have a substituent.
Examples of the substituent of the substituted arylene group, the substituted aryl group and the substituted heterocyclic group include a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group and an alkoxy group.

When m is 3 or more, L ¹ represents a trivalent or higher aliphatic group, a trivalent or higher aromatic group, a trivalent or higher heterocyclic group, or an alkylene group, a substituted alkylene group, an arylene group, or a substituted arylene. A group, a divalent heterocyclic group, —O—, —S—, —NH—, —NR—, —N <, —CO—, —SO— or —SO ₂ — is preferable. R is an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group.
The trivalent or higher aliphatic group may have a cyclic structure or a branched structure. The number of carbon atoms in the aliphatic group is preferably 1 to 20, more preferably 1 to 15, still more preferably 1 to 10, and most preferably 1 to 8.
The aliphatic group may have a substituent. Examples of the substituent include a halogen atom, an aryl group, a substituted aryl group, and an alkoxy group.
The aromatic group is preferably a benzene ring residue. The aromatic group may have a substituent. Examples of the substituent include a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, and an alkoxy group.
The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group include a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkoxy group, oxo (═O) and thio (═S).
L ¹ may constitute a main chain of a polymer composed of m repeating units.

R ¹ , R ² and R ³ are each independently preferably a hydrogen atom, a halogen atom or an alkyl group, more preferably a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms. More preferably, it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or methyl, and most preferably a hydrogen atom.

The linking group L ¹ of the formula (I) is a urethane bond (—NH—CO—O— or —NR—CO—O—, wherein R is an alkyl group, a substituted alkyl group, an aryl group, or a substituted aryl group). , A polymer image having excellent printing durability can be formed. Polymerizable compounds containing a urethane bond are described in JP-A-51-37193, JP-B-2-32293, and JP-A-2001-117217.

The linking group L ¹ of the formula (I) may be a partial structure having liquid crystallinity. In other words, a liquid crystalline compound having an ethylenically unsaturated group (-CR ¹ = CR ² R ^{3 in the} above formula (I)) can be used as the polymerizable compound. Liquid crystalline compounds having a polymerizable group are commonly used in the technical field of optical materials, particularly in the production of retardation plates and optical compensation sheets.
The melting point of the liquid crystalline compound having an ethylenically unsaturated group is preferably 30 to 300 ° C, more preferably 50 to 270 ° C, further preferably 70 to 240 ° C, and most preferably 90 to 210 ° C.
The ratio of the ethylenically unsaturated group contained in the liquid crystal compound is preferably 5.0 mmol or more, more preferably 7.0 mmol or more, per 1 g of the liquid crystal compound.
The liquid crystal compound is preferably a rod-like liquid crystal compound or a discotic liquid crystal compound. The liquid crystal compound may be a polymer liquid crystal.

Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferred.
The rod-like liquid crystal compound includes a metal complex. Moreover, the liquid crystal polymer which contains a rod-shaped liquid crystalline compound in a repeating unit can also be used as a rod-shaped liquid crystalline compound. In other words, the rod-like liquid crystalline compound may be bonded to a (liquid crystal) polymer.
For rod-like liquid crystalline compounds, see Chapter 4, Chapter 7 and Chapter 11 of the Chemistry of the Quarterly Chemical Review Vol. 22 Liquid Crystal Chemistry (1994) edited by the Chemical Society of Japan, and the 142nd Committee of the Japan Society for the Promotion of Science. Described in Chapter 3.
The rod-like liquid crystalline compound preferably has two ethylenically unsaturated groups at both ends of the rod-like molecular structure.

A discotic liquid crystal compound is more preferable than a rod-like liquid crystal compound. That is, the liquid crystal compound preferably has many ethylenically unsaturated groups. A discotic liquid crystalline compound (generally capable of introducing four or more ethylenically unsaturated groups) has more ethylene than a rod-like liquid crystalline compound (generally, the number of ethylenically unsaturated groups is two or less). It can have an unsaturated group.
Examples of the discotic liquid crystalline compound include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physics lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and cyclohexane derivatives described in J. Am. M. Lehn et al. Chem. Commun. 1794 (1985); Zhang et al., J. Am. Chem. Soc. 116, page 2655 (1994), and azacrown and phenylacetylene macrocycles.

A discotic liquid crystalline compound is a compound having a general molecular structure in which a linear alkyl group, an alkoxy group, or a substituted benzoyloxy group is substituted radially with respect to the mother nucleus at the center of the molecule. , Showing liquid crystallinity.
Examples of the discotic liquid crystalline compound are described in JP-A-8-50206. The discotic liquid crystalline compound having a polymerizable group is described in JP-A-8-27284.

  In order to introduce an ethylenically unsaturated group into the discotic liquid crystalline compound, it is necessary to bond an ethylenically unsaturated group as a substituent to the discotic core of the discotic liquid crystalline compound. However, when an ethylenically unsaturated group is directly connected to the disk-shaped core, it becomes difficult to maintain the orientation state in the polymerization reaction. Therefore, it is preferable to introduce a linking group between the discotic core and the ethylenically unsaturated group. Accordingly, the discotic liquid crystalline compound having an ethylenically unsaturated group is preferably represented by the following formula (II).

(II) D (-LQ) n
Where D is a discotic core; L is a divalent linking group, Q is an ethylenically unsaturated group (-CR ¹ = CR ² R ^{3 in} formula (I) above) and n Is an integer from 4 to 12.
An example of the disk-shaped core (D) is shown below. In each of the following examples, LQ (or QL) means a combination of a divalent linking group (L) and an ethylenically unsaturated group (Q).

  In the formula (II), the divalent linking group (L) is selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, —S—, and combinations thereof. A divalent linking group is preferred. The divalent linking group (L) is a divalent combination of at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO-, -NH-, -O-, and -S-. More preferably, it is a linking group. The divalent linking group (L) is most preferably a divalent linking group in which at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO- and -O- are combined. . The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The number of carbon atoms in the arylene group is preferably 6 to 10.

  Examples of the divalent linking group (L) are shown below. The left side is bonded to the discotic core (D), and the right side is bonded to the polymerizable group (Q). AL represents an alkylene group or an alkenylene group, and AR represents an arylene group. The alkylene group, alkenylene group and arylene group may have a substituent (eg, an alkyl group).

L1: -AL-CO-O-AL-
L2: -AL-CO-O-AL-O-
L3: -AL-CO-O-AL-O-AL-
L4: -AL-CO-O-AL-O-CO-
L5: -CO-AR-O-AL-
L6: -CO-AR-O-AL-O-
L7: -CO-AR-O-AL-O-CO-
L8: -CO-NH-AL-
L9: -NH-AL-O-
L10: -NH-AL-O-CO-

L11: -O-AL-
L12: -O-AL-O-
L13: -O-AL-O-CO-
L14: -O-AL-O-CO-NH-AL-
L15: -O-AL-S-AL-
L16: -O-CO-AR- (O-AL) m-
L17: -O-CO-AR- (O-AL) m-O-
L18: -O-CO-AR- (O-AL) m-CO-
L19: -O-CO-AR- (O-AL) m-O-CO-
L20: -S-AL-

L21: -S-AL-O-
L22: -S-AL-O-CO-
L23: -S-AL-S-AL-
L24: -S-AR-AL-
(Ii) m: an integer from 1 to 6

  In the formula (II), n is an integer of 4 to 12. A specific number is determined according to the type of the disk-shaped core (D). In addition, although the combination of several L and Q may differ, it is preferable that it is the same.

It is also preferred that the linking group L ¹ of the formula (I) contains a cyclic amide structure.
The cyclic amide structure is preferably a 5-membered ring or a 6-membered ring.
It is preferable that a plurality of amide bonds exist in the cyclic structure, and it is more preferable that three or more amide bonds exist.
Examples of cyclic amide structures include 2-imidazolidinone ring (ethylene urea ring), trimethylene urea ring, 2,4-imidazolidinedione ring, 2,4-thiazolidinedione ring, hexahydro-1,3,5-triazine A dione ring, a 2,4,5-imidazolidinetrione ring, a tetrahydro-1,2,4-triazoledione ring, a 2-oxazolidione ring, a uracil ring, a barbituric acid ring and an isocyanuric acid ring are included. A hexahydro-1,3,5-triazinedione ring, a uracil ring, a barbituric acid ring and an isocyanuric acid ring are preferred, a barbituric acid ring and an isocyanuric acid ring are more preferred, and an isocyanuric acid ring is most preferred.
The cyclic amide may have a substituent other than an ethylenically unsaturated group or a linking group with another cyclic amide. Examples of the substituent are the same as the examples of the substituent of the heterocyclic group in the formula (I).
Cyclic amides have tautomerism between keto type (eg, isocyanuric acid) and enol type (eg, cyanuric acid). The name cyclic amide means keto type, but the cyclic amide may have an enol type cyclic structure.

More preferably, the linking group L ¹ of the formula (I) includes a plurality of cyclic amide structures. The plurality of cyclic amide structures are preferably bonded via a linking group rather than directly connected. The cyclic amide structure and the ethylenically unsaturated group are preferably bonded via a linking group rather than directly connected.
The polymerizable compound containing a plurality of cyclic amide structures is preferably represented by the following formula (III).

^{(III) L 3 [-Cy {} -L 8 (-Q) r} q] p

In the formula (III), L ³ is a p-valent linking group. p is an integer of 2 or more. The definition of the linking group is the same as L ^{1 in} formula (I).
An example of L ³ is shown below.

In formula (III), Cy is a q + 1 valent cyclic amide. q is an integer of 1 or more.
An example of Cy is shown below.

In the formula (III), L ⁸ is an r-valent linking group. r is an integer of 1 or more. The definition of the linking group is the same as L ^{1 in} formula (I).
Hereinafter, examples of L ^8.

Examples of ethylenically unsaturated polymerizable compounds containing a plurality of cyclic amide structures are shown below. In the following examples, the exemplified numbers of L ³ , Cy and L ^{8 in} the above-mentioned formula (III) are cited. Vi is a vinyl group and iPr is an isopropenyl group, both of which are ethylenically unsaturated polymerizable groups.

M-1: L31 [-Cy1 {-L84-Vi} ₂ ] ₂
M-2: L32 [-Cy1 {-L81-Vi} ₂ ] ₂
M-3: L33 [-Cy1 {-L81-Vi} ₂ ] ₂
M-4: L34 [-Cy1 {-L81-Vi} ₂ ] ₂
M-5: L35 [-Cy1 {-L81-iPr} ₂ ] ₂
M-6: L36 [-Cy1 {-L81-iPr} ₂ ] ₂
M-7: L37 [-Cy1 {-L81-Vi} ₂ ] ₂
M-8: L38 [-Cy2 {-L81-Vi} ₂ ] ₂
M-9: L39 [-Cy1 {-L81-Vi} ₂ ] ₂
M-10: L40 [-Cy1 {-L81-Vi} ₂ ] ₂

M-11: L41 [-Cy1 {-L81-iPr} ₂ ] ₂
M-12: L42 [-Cy1 {-L81-iPr} ₂ ] ₂
M-13: L43 [-Cy1 {-L81-Vi} ₂ ] ₂
M-14: L44 [-Cy1 {-L81-Vi} ₂ ] ₂
M-15: L45 [-Cy1 {-L81-Vi} ₂ ] ₂
M-16: L46 [-Cy1 {-L81-Vi} ₂ ] ₂
M-17: L47 [-Cy1 {-L81-Vi} ₂ ] ₂
M-18: L48 [-Cy1 {-L81-iPr} ₂ ] ₃
M-19: L49 [-Cy1 {-L81-Vi} ₂ ] ₄
M-20: L50 [-Cy1 {-L81-Vi} ₂ ] ₂

M-21: L51 [-Cy1 {-L81-Vi} ₂ ] ₂
M-22: L52 [-Cy1 {-L81-Vi} ₂ ] ₂
M-23: L53 [-Cy1 {-L81-Vi} ₂ ] ₂
M-24: L54 [-Cy2 {-L81-Vi} ₂ ] ₂
M-25: L55 [-Cy1 {-L81-Vi} ₂ ] ₂
M-26: L56 [-Cy1 {-L81-Vi} ₂ ] ₃
M-27: L57 [-Cy1 {-L81-Vi} ₂ ] ₂
M-28: L58 [-Cy1 {-L81-Vi} ₂ ] ₂
M-29: L59 [-Cy1 {-L81-Vi} ₂ ] ₂
M-30: L60 [-Cy1 {-L81-Vi} ₂ ] ₂

M-31: L61 [-Cy1 {-L81-Vi} ₂ ] ₂
M-32: L62 [-Cy1 {-L83-Vi} ₂ ] ₂
M-33: L63 [-Cy1 {-L82 (-Vi) ₂ } ₂ ] ₂
M-34: L64 [-Cy1 {-L90-Vi} ₂ ] ₂
M-35: L65 [-Cy1 {-L91 (-Vi) ₃ } ₂ ] ₂
M-36: L66 [-Cy2 {-L92 (-Vi) ₂ } ₂ ] ₂
M-37: L67 [-Cy3-L93-Vi] ₂
M-38: L67 [-Cy4-L81-Vi] ₂
M-39: L68 [-Cy1 {-L89 (-Vi) (-iPr) } ₂ ] ₂
M-40: L39 [-Cy1 {-L84-Vi} ₂ ] ₂

M-41: L69 [-Cy1 {-L85-Vi} ₂ ] ₂
M-42: L70 [-Cy1 {-L82 (-Vi) (-iPr) } ₂ ] ₃
M-43: L71 [-Cy1 {-L82 (-Vi) ₂ } ₂ ] ₂
M-44: L72 [-Cy1 {-L86-Vi} ₂ ] ₂
M-45: L73 [-Cy1 {-L87 (-Vi) ₂ } ₂ ] ₂
M-46: L74 [-Cy1 {-L87 (-Vi) (-iPr)} ₂ ] ₂
M-47: L75 [-Cy1 {-L89 (-iPr) ₂ } ₂ ] ₂
M-48: L76 [-Cy1 {-L81-Vi} ₂ ] ₃

The ethylenically unsaturated polymerizable compound preferably has a molecular weight of 400 or more, and more preferably has a molecular weight of 600 to 3000.
Two or more kinds of polymerizable compounds may be used in combination.
The image forming layer preferably contains an ethylenically unsaturated polymerizable compound in the range of 5 to 80% by mass, more preferably in the range of 10 to 70% by mass, and in the range of 15 to 60% by mass. Is more preferable, and most preferably in the range of 20 to 50% by mass.

(4) Polymer binder The image forming layer of the lithographic printing plate precursor according to the invention may contain a polymer binder.
Any conventionally known polymer binder can be used without any particular limitation. Although it may be a hydrophobic polymer or a hydrophilic polymer, it is preferably a hydrophobic polymer.
The main chain of the binder polymer is preferably selected from hydrocarbon (polyolefin), polyester, polyamide, polyimide, polyurea, polyurethane, polyether and combinations thereof. A main chain containing hydrocarbon or polyurethane is more preferred. The polymer comprising the hydrocarbon main chain is preferably poly (meth) acrylic acid, poly (meth) acrylic ester, poly (meth) acrylamide, poly (meth) acrylonitrile, polystyrene, polyvinyl acetal or a copolymer thereof. Polyvinyl acetal and polyurethane are particularly preferred.
Various polymers used in the image forming layer are described in “POLYMER HANDBOOK”, FORTH EDITION, J. BRANDRUP, EH IMMERGUT, and EA GRULKE, JOHN WILEY & SONS, INC.

It is preferable that the binder polymer does not contain an acidic group. Polymers containing acidic groups may be adsorbed on the support and inhibit on-press development. An acidic group means a group having an acid dissociation constant (pKa) of less than 7, for example, —COOH, —SO ₃ H, —OSO ₃ H, —PO ₃ H ₂ , —OPO ₃ H ₂ .
The glass transition temperature (Tg) of the polymer is preferably 50 to 300 ° C, more preferably 70 to 250 ° C, and most preferably 80 to 200 ° C. In order to increase the glass transition temperature of the polymer, an amide bond (—NRCO—), an imide bond (—N═CO—), a urethane bond (—NRCOO—), a urea bond (—NRCONR—), a sulfone are added to the polymer side chain. An amide bond (—SO ₂ NR—), a sulfonyl bond (—SO ₂ —) or a cyano group (—CN) can be introduced. R is a hydrogen atom or a hydrocarbon group. Binder polymers having a side chain having a function of increasing the glass transition temperature are disclosed in JP-A Nos. 2000-250216, 2001-51408, 2001-109138, 2001-242612, 2002-122984, 2002-2002. There are descriptions in each publication of No. 122989.

The binder polymer preferably has an addition polymerizable group in the side chain. The addition polymerizable group is preferably an ethylenically unsaturated group, and is an ethylenically unsaturated group corresponding to -CR ¹ = CR ² R ³ in the formula (I) described for the ethylenically unsaturated polymerizable compound. More preferably. The ethylenically unsaturated group is preferably vinyl (R ¹ : hydrogen atom, R ² : hydrogen atom, R ³ : hydrogen atom) or isopropenyl (R ¹ : methyl, R ² : hydrogen atom, R ³ : hydrogen atom). . Vinyl is preferably bonded to methylene (vinyl + methylene = allyl) or carbonyl (vinyl + carbonyl = acryloyl), and isopropenyl is preferably bonded to carbonyl (isopropenyl + carbonyl = methacryloyl). More preferred is acryloyl or methacryloyl, and more preferred is methacryloyl.

The ethylenically unsaturated group is preferably contained in 0.1 to 10.0 mmol, more preferably 1.0 to 7.0 mmol, and more preferably 2.0 to 5.0 mmol in 1 g of the polymer. More preferably. The content of ethylenically unsaturated groups in the polymer can be easily measured by iodine titration.
Binder polymers having an addition polymerizable group on the side chain are disclosed in JP-A Nos. 2000-352824, 2001-109139, 2001-125265, 2001-117229, 2001-125257, 2001-228608, There are descriptions in JP-A Nos. 2002-62648, 2002-156757, 2002-251008, 2002-229207, and 2002-162741.

The mass average molecular weight of the polymer is preferably 500 to 1,000,000, more preferably 1,000 to 500,000, still more preferably 2,000 to 300,000, and most preferably 5,000 to 200,000.
The binder polymer is preferably contained in the image forming layer in an amount of 5 to 80% by mass, more preferably 10 to 70% by mass, further preferably 15 to 60% by mass, It is particularly preferable that the content is 50 to 50% by mass.

The main chain of the hydrophobic polymer can have a substituent. Examples of the substituent include a halogen atom (F, Cl, Br, I), hydroxyl, mercapto, cyano, aliphatic group, aromatic group, heterocyclic group, —O—R, —S—R, —CO—. R, —NH—R, —N (—R) ₂ , —N ⁺ (—R) ₃ , —CO—O—R, —O—CO—R, —CO—NH—R, —NH—CO— R and —P (═O) (— O—R) ₂ are included. Each R is an aliphatic group, an aromatic group or a heterocyclic group.
A plurality of substituents of the main chain may be bonded to form an aliphatic ring or a heterocyclic ring. The ring formed may have a spiro bond relationship with the main chain. The formed ring may have a substituent. Examples of the substituent include oxo (═O) in addition to the substituent of the main chain.

The hydrophilic group of the hydrophilic polymer is preferably hydroxyl or polyether, more preferably hydroxyl. Hydroxyl is preferred to alcohol over phenol. The hydrophilic polymer may have other hydrophilic groups (cationic group, anionic group) in addition to the nonionic hydrophilic group.
As the hydrophilic polymer, various natural or semi-synthetic polymers or synthetic polymers can be used.
As natural or semi-synthetic polymers, polysaccharides (eg, gum arabic, starch derivatives, carboxymethyl cellulose, sodium salts thereof, cellulose acetate, sodium alginate) or proteins (eg, casein, gelatin) can be used.

Examples of synthetic polymers having hydroxyl as a hydrophilic group include polyhydroxyethyl methacrylate, polyhydroxyethyl acrylate, polyhydroxypropyl methacrylate, polyhydroxypropyl acrylate, polyhydroxybutyl methacrylate, polyhydroxybutyl acrylate, polyallyl alcohol, polyvinyl alcohol And poly-N-methylolacrylamide.
Examples of synthetic polymers having other hydrophilic groups (eg, amino, ether bond, hydrophilic heterocyclic group, amide bond, sulfo, ester bond) include polyethylene glycol, polypropylene glycol, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone , Polyacrylamide, polymethacrylamide, poly N-isopropylacrylamide, poly N, N-dimethylacrylamide, poly N-acryloylmorpholine, poly N-vinylpyrrolidone, poly-2-ethyl-2-oxazoline, poly-2-acrylamide-2- Methyl propane sulfonic acid and its salts, polyvinyl acetate, polyacrylamide, polyvinyl methyl ether are included.

A copolymer having two or more kinds of hydrophilic synthetic polymer repeating units may be used. A copolymer including a repeating unit of a hydrophilic synthetic polymer and a repeating unit of a hydrophobic synthetic polymer (eg, polyvinyl acetate or polystyrene) may be used. Examples of copolymers include vinyl alcohol-vinyl acetate copolymers (partially saponified polymers of polyvinyl acetate). When a vinyl alcohol-vinyl acetate copolymer is synthesized by partial saponification of polyvinyl acetate, the saponification degree is preferably 60% or more, and more preferably 80% or more.
Two or more kinds of polymer binders may be used in combination.
The polymer binder is preferably contained in the image forming layer in an amount of 5 to 90% by mass, and more preferably 30 to 80% by mass.

[Other optional components of image forming layer]
A colorant can be added to the image forming layer for the purpose of distinguishing between an image portion after image formation and a non-image portion. As the colorant, a dye or pigment having a large absorption in the visible region is used. Examples of colorants include oil yellow # 101, oil yellow # 103, oil pink # 312, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (or above) Orient Pure Chemical Industries, Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), and Methylene Blue (CI52015). The dye used as the colorant is described in JP-A-62-293247. Inorganic pigments such as titanium oxide can also be used as the colorant.
The amount of the colorant added is preferably 0.01 to 10% by mass of the image forming layer.

Inorganic fine particles may be added to the image forming layer. The inorganic compound constituting the fine particles is preferably an oxide (eg, silica, alumina, magnesium oxide, titanium dioxide) or a metal salt (eg, magnesium carbonate, calcium alginate).
The average particle size of the inorganic fine particles is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.
The inorganic fine particles are preferably contained in the image forming layer in an amount of 1.0 to 70% by mass, and more preferably 5.0 to 50% by mass.

In the image forming layer, nonionic surfactants (described in JP-A Nos. 62-251740 and 3-208514), anionic surfactants, and cationic surfactants (described in JP-A No. 2-195356) are used. , Amphoteric surfactants (described in JP-A-59-121044 and JP-A-4-13149) or fluorine-containing surfactants can be added. Among these, nonionic surfactants and anionic surfactants are preferable. For on-press development, the use of an anionic surfactant is particularly preferred.
The surfactant is preferably contained in the image forming layer in an amount of 0.05 to 15% by mass, and more preferably 0.1 to 5% by mass.

In order to impart flexibility to the image forming layer, a plasticizer may be added. Examples of plasticizers include polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate and tetrahydrofurfuryl oleate .
The amount of the plasticizer added to the image forming layer is preferably 0.1 to 50% by mass, and more preferably 1 to 30% by mass.

  In the present invention, several modes can be used as a method of incorporating the above-described constituent components into the image forming layer. One is a molecular dispersion type (uniform) image forming layer in which the constituent components are dissolved and applied in an appropriate solvent as described in, for example, JP-A-2002-287334. In another embodiment, as described in, for example, JP-A Nos. 2001-277740 and 2001-277742, all or part of the constituent components are encapsulated in microcapsules and contained in the image forming layer. It is a capsule type image forming layer. further. In the microcapsule type image forming layer, the constituent component may be contained outside the microcapsule. Here, it is preferable that the microcapsule type image forming layer includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule.

  As a method for microencapsulating the above components, a known method can be applied. For example, as a method for producing microcapsules, a method using coacervation found in U.S. Pat. Nos. 2,800,547 and 2,800,498, U.S. Pat. No. 3,287,154, JP-B-38-19574, 42-446 by the interfacial polymerization method, US Pat. No. 3,418,250, US Pat. No. 3,660,304 by polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcinol A method using a wall forming material, a method using a wall material such as melamine-formaldehyde resin, hydroxycellulose, etc. found in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method by monomer polymerization, spray drying method found in British Patent No. 930422, US Pat. No. 3,111,407, electrolytic dispersion cooling method seen in British Patent Nos. 952807, 967074, etc. However, it is not limited to these.

A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as an ethylenically unsaturated bond which can be introduce | transduced into the said binder polymer.
The average particle size of the microcapsules is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.

The image forming layer is prepared by dissolving, dispersing or emulsifying each component including microcapsules in an appropriate liquid medium, preparing a coating solution, applying the solution on the above-mentioned aluminum support, and drying to remove the liquid medium. Can be formed. Examples of the liquid medium used for the coating solution include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2- Contains propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene and water It is. Two or more kinds of liquids may be mixed and used.
The total solid concentration of the coating solution is preferably 0.1 to 50% by mass.
The dry coating amount of the image forming layer is preferably 0.5 to 5.0 g / m ² .

  In the present invention, in addition to the above basic components, a small amount of thermal polymerization is prevented in order to prevent unnecessary thermal polymerization of the ethylenically unsaturated polymerizable compound that can be polymerized during the production or storage of the image-forming composition. It is desirable to add an agent. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the weight of the total composition. In addition, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition due to oxygen, and a lithographic printing original plate is dried after coating on a support or the like. In this process, it may be unevenly distributed on the surface of the image forming layer. The amount of the higher fatty acid derivative added is preferably about 0.5% by mass to about 10% by mass of the total composition.

[Middle layer]
Further, the lithographic printing plate precursor used in the printing method of the present invention may be provided with an intermediate layer between the support and the image forming layer for the purpose of improving the adhesion between the support and the image forming layer. good.
The intermediate layer is not particularly limited, and examples thereof include those described in JP-A Nos. 2001-175001, 2002-31068, and 2002-323770.

[Water-soluble overcoat layer]
In order to prevent contamination of the image forming layer surface with an oleophilic substance, a water-soluble overcoat layer can be provided on the image forming layer.
The water-soluble overcoat layer is made of a material that can be easily removed during printing. For that purpose, it is preferable to form a water-soluble overcoat layer from a water-soluble organic polymer. Examples of water-soluble organic polymers include polyvinyl alcohol, polyvinyl acetate, polyacrylic acid, alkali metal salts or amine salts thereof, polymethacrylic acid, alkali metal salts or amine salts thereof, polyacrylamide, polyhydroxyethyl acrylate, polyvinyl Pyrrolidone, polyvinyl methyl ether, poly-2-acrylamido-2-methyl-1-propanesulfonic acid, its alkali metal salt or amine salt, gum arabic, cellulose ether (eg, carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose), dextrin and its Derivatives (eg, white dextrin, enzymatically degraded etherified dextrin pullulan) are included.

You may use the copolymer which has 2 or more types of repeating units of water-soluble organic polymer. Examples of copolymers include vinyl alcohol-vinyl acetate copolymers (partially saponified polymers of polyvinyl acetate) and vinyl methyl ether-maleic anhydride copolymers. When a vinyl alcohol-vinyl acetate copolymer is synthesized by partial saponification of polyvinyl acetate, the saponification degree is preferably 65% by mass or more.
Two or more types of water-soluble organic polymers may be used in combination.

The dye or pigment having the maximum absorption at 700 to 1200 nm may be added to the overcoat layer. The dye or pigment having a maximum absorption at 700 to 1200 nm added to the overcoat layer is preferably water-soluble.
A nonionic surfactant (eg, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl ether) can be added to the coating liquid for the overcoat layer.
In addition, a colorant (e.g., a water-soluble dye) that is excellent in the transmittance of a laser having a wavelength of 700 to 1200 nm and that can efficiently absorb light having a wavelength not related to exposure can be added without causing a decrease in sensitivity. , Can enhance safelight suitability.
The overcoat layer (protective layer) is described in US Pat. No. 3,458,311 and JP-A-55-49729.
The coating amount of the overcoat layer is preferably 0.01 to 3.0 g / m ² . It is more preferably 0.05 to 2.5 g / m ² , further preferably 0.1 to 2.0 g / m ² , and further preferably 0.2 to 1.5 g / m ^2. Preferably, it is 0.25 to 1.0 g / m ² .

[Image exposure process]
The lithographic printing plate precursor is image-exposed by scanning exposure corresponding to original data (usually digital data) using a laser having a wavelength of 700 to 1200 nm. As the laser having a wavelength of 700 to 1200 nm, a solid high-power infrared laser (for example, a semiconductor laser or a YAG laser) is preferable. As an image forming mechanism, photothermal conversion occurs by laser exposure having a wavelength of 700 to 1200 nm to an image forming layer containing a dye or pigment having a maximum absorption at 700 to 1200 nm, and carboxylate ions and onium ions are generated by the generated heat. It is considered that an active species (radical) is decomposed and the ethylenically unsaturated polymerizable compound is polymerized by this active species to form an image portion that cannot be removed with ink and fountain solution (so-called heat mode). ). However, generation of active species due to electron transfer or energy transfer from a dye or pigment having a maximum absorption at 700 to 1200 nm to a salt of carboxylate ion and onium ion, so-called photon mode, and also a mixture of heat mode and photon mode. It doesn't matter.

[Plate making process and printing process]
The lithographic printing plate precursor heated in the form of an image is immediately mounted on a printing press, and printing and printing can be carried out in succession by simply printing with ink and dampening water in the usual procedure. That is, when the printing press is operated with the lithographic printing plate precursor mounted on the printing press, the image forming layer in the non-heated portion (non-image portion) can be removed by dampening water, ink, or rubbing. .

When a printing machine having a laser exposure device (described in Japanese Patent No. 2938398) is used, a lithographic printing plate precursor is mounted on a printing machine cylinder, exposed to a laser mounted on the printing machine, and then dampened. It is also possible to apply on-machine development with water or ink (exposure to printing are continuously processed).
Further, the plate-making printing plate can be further heated to react with the unreacted heat-reactive compound remaining in the image area, thereby further improving the strength (printing durability) of the printing plate.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

Aluminum plates used in Examples and Comparative Examples of the present invention were prepared from five types of molten aluminum alloys containing alloy components of Composition A to Composition E shown in Table 1 below. The production of the aluminum plate is as follows. First, a molten aluminum treatment including degassing and filtration was performed on the molten aluminum alloy, and an ingot having a thickness of 500 mm was produced by a DC casting method. After chamfering the ingot surface to 10 mm, the ingot was heated, hot rolling was started at 400 ° C. without performing a soaking treatment, and rolling was performed until the plate thickness reached 4 mm. Next, after cold rolling to a thickness of 1.5 mm and intermediate annealing, after finishing again to 0.24 mm by cold rolling to correct the flatness, the aluminum plate for the examples and comparative examples of the present invention Produced.
Compositions A to D have Al purity and all impurity elements within a predetermined range, and are within a preferable range for the present invention. Composition E is a composition in which Al purity and five impurity elements of Fe, Si, Mn, Mg, and Zn are within a predetermined range, and are within a preferable range for the present invention.

  Using the aluminum plates having the compositions shown in A to E of Table 1, each treatment was performed in the following procedures (1) to (6) to produce aluminum supports A to E for planographic printing plates. Moreover, after each surface treatment and water washing, liquid draining was performed with a nip roller, and water washing was performed by spraying water from a spray tube.

(1) Mechanical surface roughening treatment While supplying a suspension of silica sand having a specific gravity of 1.12 (abrasive, average particle size 25 μm) and water as a polishing slurry liquid to the surface of the aluminum plate with a spray tube, nylon Mechanical roughening was performed using a brush roller with a rotating brush.
The material of the nylon brush used was nylon-6,10, the hair length was 50 mm, and the hair diameter was 0.295 mm. The nylon brush is formed by making holes in a Φ300 mm stainless steel tube so as to be dense.
The brush roller used was three nylon brushes, and the distance between the two support rollers (Φ200 mm) provided at the lower part of the brush was 300 mm.

The brush roller manages the load of the drive motor that rotates the brush with respect to the load before the nylon brush is pressed against the aluminum plate, and the average surface roughness (Ra) of the roughened aluminum plate is 0. It pressed down so that it might become 45 micrometers. The rotating direction of the brush was the same as the moving direction of the aluminum plate. Thereafter, the aluminum plate was washed with water.
In addition, the concentration of the abrasive is referred to a table created in advance from the relationship between the abrasive concentration, temperature and specific gravity, the abrasive concentration is obtained from the temperature and specific gravity, water and abrasive are added by feedback control, The concentration of the abrasive was kept constant. Moreover, since the surface shape of the roughened aluminum plate changes when the abrasive is pulverized to reduce the particle size, the abrasive having a small particle size is sequentially discharged out of the system by the cyclone. The particle size of the abrasive was in the range of 1 to 35 μm.

(2) Etching treatment in alkaline aqueous solution:
An aqueous solution containing 27% by weight of NaOH and 6.5% by weight of aluminum ions and having a liquid temperature of 70 ° C. was sprayed onto the aluminum plate with a spray tube, and the aluminum plate was subjected to an alkali etching treatment. The amount of dissolution of the side surface of the aluminum plate to be subjected to subsequent electrochemical roughening treatment was 8 g / m ² , and the amount of dissolution on the back surface was 2 g / m ² .
The concentration of the etching solution used in the alkali etching treatment is determined in advance by referring to a table created from the relationship between the NaOH concentration, the aluminum ion concentration, the temperature, the specific gravity, and the conductivity of the solution, and the temperature, specific gravity, and The concentration of the etching solution was obtained from the electrical conductivity, and water and a 48 mass% NaOH aqueous solution were added by feedback control to keep the concentration of the etching solution constant. Then, the water washing process was performed.

(3) Desmut treatment:
Next, an aqueous nitric acid solution having a liquid temperature of 35 ° C. was sprayed onto the aluminum plate using a spray, and desmut treatment was performed for 10 seconds. As the aqueous nitric acid solution used for this desmut, the overflow waste liquid from the electrolyzer used in the next step was used. Next, several spray tubes for spraying the desmut treatment liquid were installed so that the surface of the aluminum plate was not dried until the next step.

(4) Electrochemical roughening treatment in nitric acid aqueous solution:
The electrochemical surface roughening treatment was continuously performed using two tanks of the trapezoidal wave alternating current shown in FIG. 1 and the electrolytic apparatus shown in FIG. As the acidic aqueous solution, an aqueous nitric acid solution containing 1% by mass of nitric acid (including 0.5% by mass of aluminum ions and 0.007% by mass of ammonium ions) was used, and the liquid temperature was 50 ° C. The alternating current has a time tp and tp ′ of 1 msec until the current value reaches a peak from zero, and a carbon electrode is used as a counter electrode. The current density at the peak of the alternating current was 50 A / dm ² for both the anode and cathode of the aluminum plate. Further, the ratio (Q _C / Q _A ), duty, frequency, and total amount of electricity at the time of anode are shown in the following Table 2 between the amount of electricity at the time of anode (Q _A ) and the amount of electricity at the time of cathode (Q _C ). It was street. Thereafter, washing with water was performed by spraying.

  Concentration control of nitric acid aqueous solution adds 67% by mass of nitric acid stock solution and water in proportion to the amount of electricity, and an acidic aqueous solution (nitric acid aqueous solution) of the same volume as the addition volume of nitric acid and water overflows from the electrolyzer sequentially. And discharged outside the electrolyzer system. Along with this, referring to a table created in advance from the relationship between nitric acid concentration, aluminum ion concentration, temperature, liquid conductivity, and liquid ultrasonic propagation velocity, the temperature, conductivity, and ultrasonic propagation velocity of the aqueous nitric acid solution The concentration of the aqueous nitric acid solution was determined, and the concentration was kept constant by controlling the addition amount of the nitric acid stock solution and water sequentially.

(5) Etching treatment in alkaline aqueous solution:
An aqueous solution having a liquid temperature of 45 ° C. containing 26% by mass of NaOH and 6.5% by mass of aluminum ions was sprayed onto the aluminum plate using a spray to perform alkali etching treatment of the aluminum plate. The dissolution amount of the aluminum plate was 1 g / m ² . The concentration of the etching solution is determined in advance by referring to a table prepared from the relationship between the NaOH concentration, the aluminum ion concentration, the temperature, the specific gravity, and the electrical conductivity of the liquid. The etching solution concentration is obtained from the temperature, the specific gravity, and the electrical conductivity. And a 48% by weight aqueous NaOH solution were added and kept constant. Then, the water washing process was performed.

(6) Etching treatment in acidic aqueous solution:
Next, using an acidic etching solution having 300 g / l sulfuric acid and an aluminum ion concentration of 15 g / l, this was sprayed from the spray tube to the aluminum plate at 80 ° C. for 8 seconds to carry out an acidic etching treatment. For the concentration of the acidic etching solution, refer to the table created in advance from the relationship between the sulfuric acid concentration, aluminum ion concentration, temperature, specific gravity, and liquid conductivity. Water and 50% by weight sulfuric acid were added under control to keep constant. Then, the water washing process was performed.

Next, aluminum supports (I) to (V) for lithographic printing plates were prepared by subjecting each of the roughened aluminum supports A to E to the following anodizing treatment.
(7) Anodizing treatment:
Using an aqueous solution (containing 0.5% by mass of aluminum ions) having a sulfuric acid concentration of 170 g / l as an anodizing solution, anodizing was performed at a current density of 2 A / dm ² and a temperature of 43 ° C. for 6 minutes using a DC voltage. It was. The concentration of the anodizing solution is determined by referring to a table created in advance from the relationship between sulfuric acid concentration, aluminum ion concentration, temperature, specific gravity, and liquid conductivity. To add water and 50% by weight sulfuric acid to keep constant. Thereafter, washing with water was performed by spraying, and immersion treatment was performed for 1 minute at 170 g / l of sulfuric acid at 50 ° C., followed by washing with water. Next, it was treated with a No. 3 sodium silicate 2.5% aqueous solution at 70 ° C. for 10 seconds. Thereafter, washing with water was performed by spraying to prepare aluminum supports (I) to (V) for planographic printing plates.

Production Example 6 of Support
An aluminum support (VI) for a lithographic printing plate was produced in the same manner as in Example 1 except that the mechanical rough surface treatment was omitted.

Production Example 7 of Support
The roughened aluminum support (VI) was anodized at a sulfuric acid concentration of 170 g / l (containing 0.5% aluminum ions), a temperature of 40 ° C., 30 A / dm ² , 20 seconds, washed with water, and then pH 13 Was immersed in an aqueous solution of sodium hydroxide at 30 ° C. for 45 seconds, washed with water, then immersed in a mixed aqueous solution of NaF 0.1% / NaH ₂ PO ₄ 10% at 100 ° C. for 1 minute, and washed with water. Next, the aluminum support (VII) for lithographic printing plates was produced by processing for 10 second at 70 degreeC in 2.5% sodium silicate 2.5% aqueous solution.

Production Example 8 of Support
The roughened aluminum support (VI) was anodized with oxalic acid 50 g / L, temperature 30 ° C., current density 12 A / dm ² , electrolysis time 2 minutes, washed with water, Immersion treatment is carried out at 50 ° C. for 30 seconds, washed with water, and then treated with No. 3 sodium silicate 2.5% aqueous solution at 70 ° C. for 10 seconds to produce an aluminum support for lithographic printing plates (VIII) did.

Production Example 1 for Comparative Support
The roughened aluminum support (I) was anodized for 30 seconds with 100 g / l sulfuric acid and a current density of 20 A / dm ² , and washed with water. Next, it was treated with a No. 3 sodium silicate 2.5% aqueous solution at 70 ° C. for 10 seconds, washed with water, and an aluminum support (i) for lithographic printing plate was produced.
Production Example 2 for Comparative Support
The roughened aluminum support (I) was anodized with oxalic acid 50 g / L, temperature 30 ° C., current density 12 A / dm ² , electrolysis time 2 minutes, washed with water, Immersion treatment is performed at 50 ° C. for 60 minutes, washed with water, and then treated with a 2.5% aqueous solution of No. 3 sodium silicate at 70 ° C. for 10 seconds to produce an aluminum support (ii) for a lithographic printing plate did.
Production Example 3 for Comparative Support
An aluminum support (iii) for a lithographic printing plate of Comparative Example 3 was produced in the same manner as the aluminum support (I) except that the immersion treatment time after anodization was 4 minutes.

<Measurement of porosity>
The porosity of the anodized film was determined by the following formula (A).

  Porosity (%) = [1- (oxide film density / 3.98)] × 100 (A) formula

Here, the oxide film density (g / cm ³ ) was determined from [weight of oxide film per unit area / film thickness of oxide film]. Incidentally, 3.98 is the density (g / cm ³ ) of aluminum oxide according to the chemical handbook.
The oxide film weight per unit area was calculated from the decrease by cutting the anodized substrate into a predetermined size, dissolving it in a mason solution consisting of chromic acid / phosphoric acid. The film thickness was calculated by observing the fracture surface of the anodized film with a scanning microscope T20 manufactured by JEOL at a magnification of 10,000, and measuring 50 points to calculate the average film thickness. The results are also shown in Table 3.

<Measurement of surface pore diameter>
From the SEM photograph which observed the diameter (surface pore diameter) of the micropore exposed on the surface of the anodic oxide film with a scanning electron microscope S-900 manufactured by Hitachi, Ltd. at an acceleration voltage of 12 kV and 150,000 times under the conditions without vapor deposition. Asked. The surface pore diameter was an average value of 50 pore diameters selected at random. The results are also shown in Table 3.

  The porosity and surface pore diameter of the obtained supports (I) to (VIII) and comparative supports (i) to (iii) are shown in Table 3 below.

[Examples 1-8 and Comparative Examples 1-3]
(Formation of image forming layer)
On the obtained supports (I) to (VIII) and comparative supports (i) to (iii), an image forming layer (1) coating solution having the following composition was applied with a wire bar, and the coating was performed at 120 ° C. for 60 seconds. The image forming layer was formed by drying. The coating amount was 1.0 g / m ² .

[Image forming layer (1) coating solution composition]
Infrared absorbing dye (D-1) 2 parts by mass The following initiator (I-1) 10 parts by mass Dipentaerythritol hexaacrylate 55 parts by mass (NK ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)
The following binder polymer (B-1) 37 parts by mass The following fluorosurfactant (W-1) 6 parts by mass Methyl ethyl ketone 900 parts by mass

(Evaluation of lithographic printing plate precursor)
The resulting lithographic printing plate precursor was image-exposed with a test pattern (Trendsetter 3244VX, Creo) at a beam intensity of 10.2 W and a drum rotation speed of 150 rpm. Next, without developing, it is attached to a cylinder of a printing press (SPRINT S26, manufactured by Komori Corporation), and diluted 4% with a commercial fountain solution (IF-102, manufactured by Fuji Photo Film Co., Ltd.). The liquid was supplied as dampening water, then black ink (Values-G (black ink), manufactured by Dainippon Ink & Chemicals, Inc.) was supplied, and paper was further supplied for printing. The number of papers (on-press developability) required to obtain a good printed matter and the number of papers (print durability) that could be printed without causing smearing or blurring were evaluated. The results are shown in Table 4 below.

[Examples 9 to 16 and Comparative Examples 4 to 6]
On the image forming layer (1), a water-soluble overcoat layer (1) coating solution having the following composition was further applied so that the coating amount after drying was 0.5 g / m ^2, and at 75 ° C. for 75 seconds. Dried. The produced lithographic printing plate precursors were subjected to image exposure and evaluation in the same manner as in Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 5.

[Water-soluble overcoat layer (1) Coating solution composition]
95 parts by mass of polyvinyl alcohol (degree of saponification: 98 mol%, degree of polymerization: 500)
Polyvinylpyrrolidone / vinyl acetate copolymer 4 parts by mass (Luvitec VA 64W, manufactured by BASF)
Nonionic surfactant 1 part by mass (EMALEX710, manufactured by Nippon Emulsion Co., Ltd.)
3000 parts by mass of pure water

[Examples 17 to 24 and Comparative Examples 7 to 9]
Instead of the image forming layer (1) coating solution used in Examples 1 to 8 and Comparative Examples 1 to 3, an image forming layer (2) coating solution having the following composition was applied with a wire bar and dried at 100 ° C. for 60 seconds. Thus, the coating amount was set to 0.7 g / m ² . The produced lithographic printing plate precursors were subjected to image exposure and evaluation in the same manner as in Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 6.

[Image forming layer (2) coating solution composition]
The following infrared absorbing dye (D-2) 7 parts by mass The following initiator (I-2) 15 parts by mass The following polymerizable compound (M-1) 55 parts by mass Polyvinyl acetal resin (ELEX B 27 parts by mass BM-S , Manufactured by Sekisui Chemical Co., Ltd.)
Sodium dodecylbenzenesulfonate 6 parts by mass (Neopelex G-25, manufactured by Kao Corporation)
900 parts by mass of methyl ethyl ketone

[Comparative Examples 10 to 17]
Examples 17 to 24 and Comparative Examples 7 to 9 were used in place of the image forming layer (2) coating solution used in Examples 17 to 24 except that a comparative image forming layer (1) coating solution having the following composition was used. Image exposure and evaluation were performed in the same manner. The results are shown in Table 6.

[Comparative image forming layer (1) Coating liquid composition]
7 parts by mass of the infrared absorbing dye (D-2) 15 parts by mass of the following initiator (IR-1) 55 parts by mass of the polymerizable compound (M-1) Polyvinyl acetal resin (Elex B 27 parts by mass BM-S , Manufactured by Sekisui Chemical Co., Ltd.)
Sodium dodecylbenzenesulfonate 6 parts by mass (Neopelex G-25, manufactured by Kao Corporation)
900 parts by mass of methyl ethyl ketone

[Examples 25-32 and Comparative Examples 18-20]
Instead of the image forming layer (1) coating solution used in Examples 1 to 8 and Comparative Examples 1 to 3, an image forming layer (3) coating solution having the following composition was applied with a wire bar and dried at 100 ° C. for 60 seconds. Thus, the coating amount was set to 1.2 g / m ² . The produced lithographic printing plate precursors were subjected to image exposure and evaluation in the same manner as in Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 7.

[Image forming layer (3) coating solution composition]
Infrared absorbing dye (D-1) used in the image forming layer (1) 2 parts by mass Initiator (I-1) used in the image forming layer (1) 10 parts by mass The following polymerizable compound (M-2) 46 46 parts by mass Fluorosurfactant (W-1) used in the image forming layer (1) 6 parts by mass Methyl ethyl ketone 900 parts by mass

[Examples 33 to 40 and Comparative Examples 21 to 23]
Instead of the image forming layer (1) coating solution used in Examples 1 to 8 and Comparative Examples 1 to 3, an image forming layer (4) coating solution having the following composition was applied with a wire bar and dried at 100 ° C. for 60 seconds. Thus, the coating amount was set to 0.7 g / m ² . The produced lithographic printing plate precursors were subjected to image exposure and evaluation in the same manner as in Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 8.

[Image forming layer (4) coating solution composition]
Infrared absorbing dye (D-1) used in the image forming layer (1) 5 parts by mass Initiator (I-1) used in the image forming layer (1) 10 parts by mass The following polymerizable compound (M-3) 50 Part by mass Binder polymer (B-3) of the following formula 42 parts by mass Fluorosurfactant (W-1) used in the image forming layer (1) 3 parts by mass Methyl ethyl ketone 900 parts by mass

[Examples 41 to 48 and Comparative Examples 24 to 26]
(Preparation of microcapsule dispersion)
17.7 parts by weight of ethyl acetate and adduct of trimethylolpropane and xylylene diisocyanate in a 1: 3 (molar ratio) (Takenate D-110N, manufactured by Mitsui Takeda Chemical Co., Ltd., containing 25% by weight of ethyl acetate) 6 7.5 parts by mass of the polymerizable compound (M-2) used in the image forming layer (2), 1.5 parts by mass of the following infrared absorbing dye (D-3) and an anionic surfactant (Pionin P) -A41C, Takemoto Oil & Fat Co., Ltd. 0.1 mass part was melt | dissolved, and the oil phase was obtained.
Separately, 37.5 parts by mass of a 4% by mass aqueous solution of polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) was prepared as an aqueous phase. The oil phase and the aqueous phase were mixed and emulsified with a homogenizer at 12000 rpm for 10 minutes under water cooling. 24.5 parts by weight of water was added to the emulsion, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours to prepare a microcapsule dispersion. The solid content concentration of the dispersion was 20.0% by mass, and the average particle size of the microcapsules was 0.36 μm.

(Preparation of lithographic printing plate precursor)
105 parts by weight of water, 45 parts by weight of the prepared microcapsule dispersion, 1 part by weight of initiator (I-1) used in the image forming layer (1) and a fluorosurfactant (Megafac F-171, Dainippon Ink 0.1 parts by mass of Chemical Industries, Ltd.) were mixed to prepare an image forming layer (5) coating solution. The image forming layer (5) coating solution was applied on the aluminum support used in Examples 1 to 8 and Comparative Examples 1 to 3, and dried at 70 ° C. for 90 seconds using an oven. Formed. The coating amount of the image forming layer after drying was 1.0 g / m ² in all cases. In this way, a lithographic printing plate precursor was produced.
(Plate making, printing and evaluation)
The prepared lithographic printing plate precursor was subjected to image exposure and evaluation in the same manner as in Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 9.

[Comparative Examples 27 to 34]
Comparison in which the initiator (I-1) of the image forming layer (5) coating liquid was changed to the following (IR-2) instead of the image forming layer (5) coating liquid used in Examples 41 to 48. Image exposure and evaluation were performed in the same manner as in Examples 41 to 48 and Comparative Examples 24 to 26 except that the image forming layer (2) coating solution was used. The results are shown in Table 9.

[Examples 49 to 56 and Comparative Examples 35 to 37]
(Preparation of microcapsule dispersion)
17 parts by mass of ethyl acetate, 10 parts by mass of trimethylolpropane and xylylene diisocyanate 1: 3 (molar ratio) adduct (Takenate D-110N, manufactured by Mitsui Takeda Chemical Co., Ltd., 25% by mass of ethyl acetate) 3.15 parts by weight of the polymerizable compound (M-3) used in the image forming layer (3), 0.35 parts by weight of the following infrared absorbing dye (D-4), 3- (N, N-diethylamino)- 1 part by mass of 6-methyl-7-anilinofluorane (ODB, manufactured by Yamamoto Kasei Co., Ltd.) and 0.1 part by mass of an anionic surfactant (Pionin P-A41C, manufactured by Takemoto Yushi Co., Ltd.) were dissolved. The oil phase was obtained.
Separately, 40 parts by mass of a 4% by mass aqueous solution of polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) was prepared as an aqueous phase.
The oil phase and the aqueous phase were mixed and emulsified with a homogenizer at 12000 rpm for 10 minutes under water cooling. 25 parts by mass of water was added to the emulsion, and the mixture was stirred at room temperature for 30 minutes and further at 40 ° C. for 3 hours to prepare a microcapsule dispersion. The solid content concentration of the dispersion was 19.8% by mass, and the average particle size of the microcapsules was 0.30 μm.

(Preparation of lithographic printing plate precursor)
100 parts by weight of water, 25 parts by weight of the prepared microcapsule dispersion, 0.5 parts by weight of the initiator (I-1) used in the image forming layer (1) and the fluorine-based surfactant used in the image forming layer (1) An image forming layer (6) coating solution was prepared by mixing 0.2 parts by mass of the agent (W-1). The image forming layer (6) coating solution was applied on the aluminum support used in Examples 1 to 8 and Comparative Examples 1 to 3, and dried in an oven at 70 ° C. for 60 seconds to obtain an image forming layer (6). Formed. The coating amount of the image forming layer after drying was 1.2 g / m ² . In this way, a lithographic printing plate precursor was produced.
(Plate making, printing and evaluation)
The prepared lithographic printing plate precursor was subjected to image exposure and evaluation in the same manner as in Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 10.

It is a figure which shows the trapezoid wave of the alternating current which can be used for an electrochemical roughening process process. It is a schematic diagram of a radial type electrolysis device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Aluminum plate 12 Radial drum roller 13a, 13b Main electrode 14 Acidic aqueous solution 15 Acidic aqueous solution supply port 16 Slit 17 Acidic aqueous solution slit 18 Auxiliary anode 19a, 19b Thyristor 20 AC power source 40 Main electrolytic cell 50 Auxiliary anode vessel

Claims (2)

A lithographic printing plate precursor capable of on-press development with at least one of an ink having an image forming layer containing the following components (1) to (3) and dampening water on an aluminum support, the aluminum support The body has a porosity defined by the following formula (A) in the range of 20 to 70% on the roughened aluminum or aluminum alloy, and the diameter of the micropores exposed on the surface is 15 nm or less. A lithographic printing plate precursor comprising an anodic oxide film.
(1) Dye or pigment having maximum absorption at 700 to 1200 nm (2) Salt of carboxylate ion and onium ion (3) Porosity (%) of ethylenically unsaturated polymerizable compound = [1- (oxide film density / 3.98)] × 100 (A) Formula [Oxide film density (g / cm ³ )
= Oxide film weight per unit area / oxide film thickness]   The step of image-exposing the lithographic printing plate precursor according to claim 1 using a laser having a wavelength of 700 to 1200 nm, at least ink and dampening water in a state where the lithographic printing plate precursor subjected to image exposure is mounted on a printing machine A lithographic printing method comprising a step of supplying any of these, removing an image forming layer in an unexposed region, and making a plate, and printing using a lithographic printing plate that has been made.

Images