JP2005186560A - Original plate for lithographic printing plate, and lithographic printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for a lithographic printing plate, which enables recording to be performed by using an infrared laser, and which is excellent in any of on-machine developability, stain-proof properties, standing-stain-proof properties, fine-line reproducibility and print wear. <P>SOLUTION: A substrate for lithographic printing plate is obtained by providing a layer of an inorganic compound particle with the major axis larger in dimension than a pore size of an anodic oxidation coating on a substrate wherein the anodic oxidation coating is provided by roughening a surface of an aluminum plate, and by fusing the inorganic compound particles together through treatment using a treating fluid capable of dissolving the inorganic compound particles. In the original plate for the lithographic printing plate, a hydrophilic layer, wherein a hydrophilic graft chain exists, and an image recording layer, which contains an infrared absorbent (A), a polymerization initiator (B) and a polymerizable compound (C) and which can be removed by using printing ink, dampening water or both of the printing ink and the dampening water, are provided on the substrate for the lithographic printing plate in this order. In a lithographic printing method, after the original plate for the lithographic printing plate is exposed to the infrared laser, on-machine development is performed, and the printing is done. <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. Specifically, a lithographic printing plate precursor capable of direct plate making that can be directly made by scanning an infrared laser based on a digital signal from a computer or the like, and the lithographic printing plate precursor subjected to a development processing step The present invention also relates to a lithographic printing method in which development is performed directly on a printing press.

In general, a lithographic printing plate comprises an oleophilic image area that receives ink in the printing process and a hydrophilic non-image area that receives dampening water. Lithographic printing utilizes the property that water and oil-based inks repel each other, so that the oleophilic image area of the lithographic printing plate is the ink receiving area, and the hydrophilic non-image area is dampened with the water receiving area (ink non-receiving area). In this method, a difference in ink adhesion is caused on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, conventionally, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Normally, after exposing a lithographic printing plate precursor through an original image such as a lithographic film, the image recording layer in the image area remains, and the image recording layer in the non-image area is dissolved with an alkaline developer or an organic solvent. The lithographic printing plate is obtained by carrying out plate making by a method of exposing the surface of the hydrophilic support by removing it.

  In the conventional plate-making process of a lithographic printing plate precursor, a step of dissolving and removing the non-image area with a developing solution or the like corresponding to the image recording layer is necessary after exposure. One of the problems is to make the system unnecessary or simplified. In particular, in recent years, disposal of waste liquids discharged with wet processing has become a major concern for the entire industry due to consideration for the global environment, and therefore, the demand for solving the above-mentioned problems has become stronger.

On the other hand, as one of simple plate making methods, an image recording layer that can remove a non-image portion of a lithographic printing plate precursor in a normal printing process is used. A method called on-press development has been proposed in which a part is removed to obtain a lithographic printing plate.
As a specific method of on-press development, for example, a method of using a lithographic printing plate precursor having an image recording layer that can be dissolved or dispersed in dampening water, an ink solvent, or an emulsion of dampening water and ink , A method of mechanically removing the image recording layer by contact with rollers or a blanket cylinder of a printing press, cohesion of the image recording layer by penetration of dampening water, ink solvent, etc. There is a method in which after the adhesive force is weakened, the image recording layer is mechanically removed by contact with rollers or a blanket cylinder.
In the present invention, unless otherwise specified, the “development process step” refers to using a device other than a printing press (usually an automatic developing machine) and bringing a liquid (usually an alkaline developer) into contact therewith. Refers to the step of removing the unexposed portion of the lithographic printing plate precursor from the infrared laser to expose the surface of the hydrophilic support, and “on-press development” refers to a process using a printing machine (typically printing ink and / or printing ink). Or a dampening solution) to remove the infrared laser unexposed portion of the lithographic printing plate precursor and expose the surface of the hydrophilic support.

  However, when an image recording layer of a conventional image recording system using ultraviolet rays or visible light is used, the image recording layer does not fix even after exposure. For example, the lithographic plate after exposure until it is mounted on a printing press. It was necessary to take a time-consuming method such as storing the printing plate precursor completely in a light-shielded state or under constant temperature conditions.

  On the other hand, in recent years, digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and various new image output methods corresponding to such digitization techniques have been put into practical use. It is becoming. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate technology for manufacturing is attracting attention. Therefore, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.

  As described above, in recent years, the simplification, drying, and no processing of plate making operations have become more desirable than ever in terms of consideration for the global environment and adaptation to digitalization. It is coming.

Recently, high-power lasers such as semiconductor lasers that emit infrared rays having a wavelength of 760 to 1200 nm, YAG lasers, etc. have become available at a low cost. Therefore, a method using these high-power lasers as an image recording means has been considered promising.
In the conventional plate-making method, imagewise exposure is performed on a photosensitive lithographic printing plate precursor at low to medium illuminance, and image recording is performed by image-like physical property change due to a photochemical reaction in an image recording layer. In contrast, in the method using the above-described high-power laser, a large amount of light energy is irradiated to the exposure region in an extremely short time, and the light energy is efficiently converted into heat energy. In the process, a thermal change such as a chemical change, a phase change, a change in form or structure is caused, and the change is used for image recording. Accordingly, image information is input by light energy such as laser light, but image recording is performed in a state in which reaction by heat energy is taken into account in addition to light energy. Usually, such a recording method using heat generated by high power density exposure is called heat mode recording, and changing light energy to heat energy is called photothermal conversion.

  The major advantages of the plate making method using heat mode recording are that the image recording layer is not exposed to light at a normal illuminance level such as indoor lighting, and that fixing of images recorded by high illuminance exposure is not essential. is there. That is, the lithographic printing plate precursor used for heat mode recording is not likely to be exposed to room light before exposure, and image fixing is not essential after exposure. Therefore, for example, if an image recording layer that is insolubilized or solubilized by exposure using a high-power laser is used, and the plate making process in which the exposed image recording layer is imaged to form a lithographic printing plate is performed by on-machine development, exposure is performed. Later, a printing system is possible in which the image is not affected even if it is exposed to ambient light in the room. Therefore, if heat mode recording is used, it is expected that a lithographic printing plate precursor suitably used for on-press development can be obtained.

On the other hand, for example, Patent Document 1 describes a lithographic printing plate precursor in which an image forming layer in which hydrophobic thermoplastic polymer particles are dispersed in a hydrophilic binder is provided on a hydrophilic support. Yes. In this Patent Document 1, the above lithographic printing plate precursor is exposed by an infrared laser, and the hydrophobic thermoplastic polymer particles are coalesced by heat to form an image, which is then mounted on a cylinder of a printing press and moistened. It is described that it is possible to perform on-press development with water and / or ink.
In this way, the method of forming an image by mere thermal fusion of fine particles shows good on-press developability, but the image strength (adhesion with the support) is extremely weak and the printing durability is insufficient. Had the problem of being.

Patent Documents 2 and 3 describe lithographic printing plate precursors containing microcapsules encapsulating a polymerizable compound on a hydrophilic support.
Furthermore, Patent Document 4 describes a lithographic printing plate precursor in which a photosensitive layer containing an infrared absorber, a radical polymerization initiator, and a polymerizable compound is provided on a support.
However, the method using the polymerization reaction as described above has a feature that the image strength is relatively good because the chemical bond density of the image portion is higher than that of the image portion formed by thermal fusion of the polymer fine particles. However, from a practical point of view, any of on-press developability, antifouling property, fine line reproducibility, and printing durability is insufficient, and it has not been put into practical use.
Furthermore, Patent Document 5 discloses a lithographic printing plate precursor containing a hydrophilic polymer on a support and having a hydrophilic layer cured with hydrolyzed tetraalkyl orthosilicate. And a lithographic printing plate precursor having a hydrophilic phase having a phase separation structure composed of two phases of a phase mainly composed of a hydrophilic polymer and a phase mainly composed of a hydrophobic polymer on a support, respectively. Has been.
Japanese Patent No. 2938397 JP 2001-277740 A JP 2002-29162 A JP 2002-287334 A JP-A-8-272087 JP-A-8-292558

  The present invention has been made in view of the inadequate conventional techniques described above, and is excellent in on-machine developability, stain resistance, neglected stain resistance, fine line reproducibility, and printing durability. The purpose is to provide a lithographic printing plate precursor.

As a result of intensive studies to achieve the above object, the present inventors have found that the above problems can be solved by the following lithographic printing plate precursor and lithographic printing method.
That is, the present invention is as follows.
(1) A layer of inorganic compound particles having a major axis larger than the pore diameter of the anodized film is provided on a support having a roughened aluminum plate and provided with an anodized film, and the inorganic compound particles are further dissolved. A hydrophilic layer in which a hydrophilic graft chain is present on a support for a lithographic printing plate obtained by fusing the inorganic compound particles by treatment with a treatment liquid obtained; (A) an infrared absorber; A lithographic printing plate precursor comprising, in this order, B) a polymerization initiator and (C) an image recording layer which contains a polymerizable compound and can be removed by printing ink, dampening water or both.
(2) The lithographic printing plate precursor as described in (1) above, wherein the treatment liquid contains at least one of fluorine and silicon.
(3) The lithographic printing plate precursor described in (1) or (2) above is mounted on a printing press and imagewise exposed with an infrared laser, or imagewise exposed with an infrared laser and then mounted on a printing press. A lithographic printing method in which printing ink and fountain solution are supplied to the lithographic printing plate precursor to remove an infrared unexposed portion of the image recording layer and print.

  According to the present invention, it is possible to provide a lithographic printing plate precursor which is excellent in on-press developability, stain resistance, neglected stain resistance, fine line reproducibility and printing durability and can be recorded by infrared irradiation.

The present invention relates to a lithographic printing plate precursor and a lithographic printing method, and the lithographic printing plate precursor of the present invention is formed on a support formed by roughening an aluminum plate and providing an anodized film, which is larger than the pore diameter of the anodized film. On a support for a lithographic printing plate obtained by providing a layer of inorganic compound particles having a large major axis, and further treating the inorganic compound particles with a treatment liquid capable of dissolving the inorganic compound particles, thereby fusing the inorganic compound particles together. A hydrophilic layer having a hydrophilic graft chain, (A) an infrared absorber, (B
And (C) an image recording layer containing a polymerizable compound and removable by printing ink, fountain solution or both in this order.
Hereinafter, the support having the inorganic compound particle layer constituting the lithographic printing plate precursor according to the invention, the hydrophilic layer, the image recording layer, and the printing method according to the invention will be described in this order.

[Inorganic compound particle layer]
<Formation of inorganic compound particle layer>
As the inorganic compound particles used in the inorganic compound particle layer provided on the support having a roughened aluminum plate and provided with the anodized film, as long as it has a major axis larger than the pore diameter of the anodized film, Although not limited, those having an average particle size of 8 to 800 nm, preferably an average particle size of 10 to 500 nm, more preferably an average particle size of 10 to 150 nm are preferable. By setting the average particle size of the particles to 8 nm or more, there is little possibility that the particles enter the inside of the micropores existing in the anodized film, and the effect of increasing the sensitivity can be sufficiently obtained. Further, when the average particle diameter of the particles is 800 nm or less, the adhesiveness with the heat-sensitive layer becomes sufficient, and the printing durability is excellent. The thickness of the particle layer is preferably 8 to 800 nm, and more preferably 10 to 500 nm.

  The inorganic compound particles used in the present invention preferably have a thermal conductivity of 60 W / (m · K) or less, more preferably 40 W / (m · K) or less, and 0.3 to 10 W / ( m · K) is particularly preferred. By setting the thermal conductivity to 60 W / (m · K) or less, the thermal diffusion to the aluminum support is sufficiently suppressed, and the effect of increasing the sensitivity is sufficiently obtained.

The method for providing the inorganic compound particle layer is not particularly limited, but the simplest method is a method by coating. An inorganic compound particle layer can be easily formed by coating an aqueous solution or an organic solvent solution containing the inorganic compound particles on the surface of the support by a coating method such as a wheeler coating method or a bar coating method, followed by drying.
Further, a method of subjecting the aluminum support to electrolytic treatment using an electrolytic solution containing the inorganic compound particles and using direct current or alternating current is preferable. Examples of the alternating current waveform used in the electrolytic treatment include a sine wave, a rectangular wave, a triangular wave, and a trapezoidal wave. In addition, the frequency of the alternating current is preferably 30 to 200 Hz, more preferably 40 to 120 Hz, from the viewpoint of the cost of manufacturing the power supply device. When a trapezoidal wave is used as the waveform of the alternating current, the time 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.
As the inorganic compound particles, Al ₂ O ₃ , TiO ₂ , SiO ₂ and ZrO ₂ are preferably used alone or in combination of two or more. The electrolytic solution is obtained, for example, by suspending the inorganic compound particles in water or the like so that the content becomes 0.01 to 20% by mass of the whole. The electrolytic solution can be adjusted in pH by, for example, adding sulfuric acid in order to charge the charge positively or negatively. The electrolytic treatment is performed, for example, using direct current, using an aluminum support as a cathode, and using the above electrolytic solution at a voltage of 10 to 200 V for 1 to 600 seconds.

<Inorganic compound particle layer sealing treatment>
In the present invention, after the inorganic compound particle layer is provided, the particle layer is sealed.
In the particle layer sealing treatment, a treatment liquid capable of dissolving the inorganic compound particles (hereinafter also simply referred to as a sealing treatment liquid) is used, and the treatment is performed with the treatment liquid to fuse the inorganic compound particles.
Although it does not specifically limit as a processing liquid which can melt | dissolve the said inorganic compound particle, The aqueous solution containing at least any one of a fluorine compound and a silicic acid compound is preferable. As a result, a lithographic printing plate support having excellent stain resistance when obtained as a lithographic printing plate can be obtained.
Preferred examples of the fluorine compound used in the present invention include metal fluorides.
Specifically, for example, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium hexafluorozirconate, potassium hexafluorozirconate, sodium hexafluorotitanate, potassium hexafluorotitanate, hexafluorozirconium Examples of the acid include hydrogen acid, hexafluorotitanium hydrogen acid, ammonium hexafluorozirconate, ammonium hexafluorotitanate, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphor fluoride, and ammonium fluoride phosphate.

Moreover, as a silicate compound used for this invention, a silicic acid and a silicate are mentioned, Among these, an alkali metal silicate is mentioned suitably.
Specific examples include sodium silicate, potassium silicate, and lithium silicate. Of these, sodium silicate and potassium silicate are preferable.
Examples of sodium silicate include No. 3 sodium silicate, No. 2 sodium silicate, No. 1 sodium silicate, sodium orthosilicate, sodium sesquisilicate, and sodium metasilicate. Examples of potassium silicate include No. 1 potassium silicate. An aluminosilicate containing aluminum or a borosilicate containing boric acid can also be used.
Examples of the silicic acid include orthosilicic acid, metasilicic acid, metadisilicic acid, metatrisilicic acid, and metatetrasilicic acid.

The concentration of each compound in the sealing treatment liquid is preferably 0.01% by mass or more, and 0.05% by mass or more in terms of sealing of the anodic oxide film with respect to the fluorine compound. More preferably, it is 0.1% by mass or more, and in terms of stain resistance, it is preferably 10% by mass or less, more preferably 1% by mass or less, and 0.5% by mass. % Or less is particularly preferable.
Further, the silicic acid compound is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 1% by mass or more in terms of stain resistance. Further, in terms of printing durability, it is preferably 10% by mass or less, more preferably 7% by mass or less, and particularly preferably 5% by mass or less.
When the sealing treatment liquid contains both a fluorine compound and a silicate compound, the ratio of each compound in the sealing treatment liquid is not particularly limited, but the mass ratio of the fluorine compound and the silicate compound is 5: The ratio is preferably 95 to 95: 5, more preferably 20:80 to 80:20.

Further, the aqueous solution containing at least one of a fluorine compound and a silicate compound may contain an appropriate amount of hydroxide such as sodium hydroxide, potassium hydroxide, or lithium hydroxide in order to increase the pH. Good. Of these, sodium hydroxide and potassium hydroxide are preferable.
Moreover, the aqueous solution containing a fluorine compound and / or a silicate compound may contain an alkaline earth metal salt or a Group 4 (Group IVB) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Is mentioned. Examples of Group 4 (Group IVB) metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium oxalate potassium, titanium sulfate, titanium tetraiodide, zirconium chloride oxide, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVB) metal salts are used alone or in combination of two or more.

The temperature of the sealing treatment liquid is preferably 10 ° C or higher, more preferably 20 ° C or higher, more preferably 100 ° C or lower, and more preferably 80 ° C or lower. .
The sealing treatment solution preferably has a pH of 8 or more, more preferably has a pH of 10 or more, preferably has a pH of 13 or less, and more preferably has a pH of 12 or less.

The method of treatment with an aqueous solution containing at least one of a fluorine compound and a silicate compound is not particularly limited, and examples thereof include a dipping method and a spray method. These may be used alone or in combination, or may be used in combination of two or more.
Of these, the dipping method is preferred. When processing using the immersion method, the processing time is preferably 1 second or longer, more preferably 3 seconds or longer, more preferably 600 seconds or shorter, and 120 seconds or shorter. More preferred.

As described above, in the present invention, an inorganic compound particle layer can be provided on the anodized film using a support obtained by roughening an aluminum plate and providing an anodized film, and the inorganic compound particles can be further dissolved. By treating with the treatment liquid and fusing the inorganic compound particles together, it is possible to have both the heat insulation effect by the inorganic compound layer and the heat insulation effect by the micropore voids.
As a preferred embodiment, the ratio of the pore diameter in the inorganic compound layer to the pore diameter in the anodized film is 1.5 or more, and the concentration of at least one of fluorine and silicon in the inorganic compound layer and the anodized film Is a lithographic printing plate support in which the ratio of the concentration of at least one of fluorine and silicon is 2 or more. Within the above range, the sealing effect is sufficient, and a high void that leads to high sensitivity can be maintained without the sealing treatment liquid permeating into the anodized film pore.

  FIG. 1 is a schematic sectional view of a lithographic printing plate support used in the present invention. As shown in FIG. 1, the lithographic printing plate support 1 of the present invention has an inner diameter of a micropore 4 in an anodized film layer 3 on the surface of a support formed by providing an anodized film layer 3 on an aluminum plate 2. It has an inorganic compound layer 7 composed of inorganic compound particles 6 having a major axis larger than 5. The opening of the micropore 4 existing in the anodized film 3 is blocked by an inorganic compound layer 7 described later, but has a void inside. In the case of the conventional sealing treatment, the micropores present in the anodized film are filled with the product through the reaction by boehmite treatment, and almost no voids are left. The present invention is greatly different from the conventional sealing treatment in that only the opening of the micropore is sealed and a void remains inside.

[Aluminum support]
<Aluminum plate (rolled aluminum)>
The aluminum plate used in the present invention is made of a dimensionally stable aluminum-based metal, that is, aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film or paper on which aluminum or an aluminum alloy is laminated or vapor-deposited can also be used. 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 can also be used.

  In the following description, various substrates made of aluminum or an aluminum alloy mentioned above or various substrates having a layer made of aluminum or an aluminum alloy are collectively used as an aluminum plate. The foreign elements that may be contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, and the content of the foreign elements in the alloy is 10% by mass or less. It is.

In the present invention, it is preferable to use a pure aluminum plate. However, it is difficult to produce completely pure aluminum in terms of refining technology, so it may contain a slightly different foreign element. Thus, the composition of the aluminum plate used in the present invention is not specified, and conventionally known and used materials such as JIS A1050, JIS A1100, and JIS.
Aluminum alloy plates such as A3005 and internationally registered alloy 3103A can be appropriately used. The aluminum plate used in the present invention has a thickness of 0.1 mm to 0.6 mm.
Degree. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's desire.

  The aluminum support used in the present invention is obtained by providing an anodic oxide film on the aluminum plate, but the manufacturing process of the aluminum support may include various processes other than the anodizing treatment.

<Roughening treatment (graining treatment)>
The aluminum plate is grained to a more preferable shape. Examples of the graining method include mechanical graining (mechanical roughening), chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, electrochemical graining (electrochemical roughening) in which electrochemical graining is carried out in hydrochloric acid electrolyte or nitric acid electrolyte, and the aluminum brush is ground with a metal wire. Mechanical graining methods such as a ball grain method in which the aluminum surface is grained with an abrasive and a brush grain method in which the surface is grained with a nylon brush and an abrasive can be used. These graining methods can be used alone or in combination.

Among them, the method for producing a grainy surface suitably used in the present invention is an electrochemical method in which graining is chemically performed in a hydrochloric acid electrolyte or a nitric acid electrolyte. A preferable amount of electricity is 50 to 400 C / dm ² when the anode is charged. More specifically, for example, in an electrolytic solution containing 0.1 to 50% by mass of hydrochloric acid or nitric acid, under conditions of a temperature of 20 to 100 ° C., a time of 1 second to 30 minutes, and a current density of 10 to 100 A / dm ² . This is done using direct current or alternating current. Electrochemical roughening is suitable for improving the adhesion between the heat-sensitive layer and the substrate because it is easy to provide fine irregularities on the surface.

  By electrochemical roughening, crater-like or honeycomb-like pits having an average diameter of about 0.5 to 20 μm can be generated on the surface of the aluminum plate at an area ratio of 30 to 100%. The provided pits have the effect of improving the resistance to smearing of the non-image area of the printing plate and the printing durability. In the electrochemical treatment, the amount of electricity necessary to provide sufficient pits on the surface, that is, the product of the current and the time during which the current is applied is an important condition in electrochemical roughening. From the viewpoint of energy saving, it is desirable that sufficient pits can be formed with a smaller amount of electricity. The surface roughness after the roughening treatment is such that the arithmetic average roughness (Ra) measured at a cutoff value of 0.8 mm and an evaluation length of 3.0 mm in accordance with JISB0601-1994 is 0.2 to 0.7 μm. Is preferred. The electrochemical roughening can also be used in combination with electrochemical roughening under different conditions or mechanical roughening.

<Etching treatment>
The grained aluminum plate is chemically etched with acid or alkali.
When an acid is used as an etching agent, it takes time to destroy the fine structure, which is disadvantageous when the present invention is applied industrially. However, this problem can be improved by using an alkali as the etching agent.
The alkali agent suitably used in the present invention is not particularly limited, and examples thereof include caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, and lithium hydroxide.
The conditions for the alkali etching treatment are not particularly limited, but the alkali concentration is preferably 1 to 50% by mass, the alkali temperature is preferably 20 to 100 ° C., and the dissolution amount of aluminum is 0.01 to is preferably from 20 g / m ^2, and more preferably 0.1-5 g / m ^2.

  After the etching process, pickling is performed to remove dirt (smut) remaining on the surface. Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid. In particular, as a method for removing smut after the electrochemical surface roughening treatment, it is preferable to use 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739. Examples thereof include a contact method and an alkali etching method as described in JP-B-48-28123.

<Anodizing treatment>
The aluminum plate treated as described above is further subjected to anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. Specifically, when direct current or alternating current is applied to an aluminum plate in an aqueous solution or non-aqueous solution of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc., alone or in combination of two or more. An anodized film can be formed on the surface of the aluminum plate.

  Under the present circumstances, the component normally contained at least by Al alloy plate, an electrode, tap water, groundwater, etc. may be contained in electrolyte solution. Furthermore, the 2nd, 3rd component may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cations such as ammonium ion; anions such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10000 ppm It may be contained at a concentration of about.

The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 1 to 80% by mass, the solution temperature is 5 to 70 ° C., and the current density is 0.5. ˜60 A / dm ² , voltage 1 to 100 V, electrolysis time 10 to 200 seconds are appropriate.
Among these anodizing treatments, a method of anodizing at a high current density in a sulfuric acid electrolyte solution described in British Patent 1,412,768, U.S. Pat. No. 3,511,661. The method of anodizing phosphoric acid as an electrolytic bath is particularly preferable.

In the present invention, the amount of the anodized film is preferably 1 to 10 g / m ² . The amount of anodized film, more preferably from 1.5~7g / m ^2, particularly preferably from 2-5 g / m ^2.

<Pore wide processing>
The aluminum support provided with the anodized film as described above may be subjected to pore-wide (PW) treatment for the purpose of adjusting the porosity of the anodized film to a suitable range, if necessary.
This treatment is performed by immersing in an acid aqueous solution or an alkali aqueous solution in order to adjust the micropore diameter of the anodized film to, for example, 8 to 500 nm, preferably 10 to 150 nm.
The acid aqueous solution is preferably an aqueous solution of sulfuric acid, phosphoric acid or a mixture thereof. The concentration of the acid aqueous solution is preferably 10 to 500 g / L, and more preferably 20 to 100 g / L. The temperature of the acid aqueous solution is preferably 10 to 90 ° C, and more preferably 40 to 70 ° C. The immersion time in the aqueous acid solution is preferably 10 to 300 seconds, and more preferably 30 to 120 seconds.
As the alkaline aqueous solution, an aqueous solution of sodium hydroxide, potassium hydroxide, lithium hydroxide or a mixture thereof is preferable. The pH of the alkaline aqueous solution is preferably 11 to 14, and more preferably 11.5 to 13.5. The temperature of the alkaline aqueous solution is preferably 10 to 90 ° C, and more preferably 20 to 60 ° C. The immersion time in the alkaline aqueous solution is preferably 5 to 300 seconds, and more preferably 10 to 60 seconds.

  In the lithographic printing plate support used in the present invention, the porosity of the anodic oxide film is preferably 20 to 70%, more preferably 30 to 60%, and 40 to 50%. Is particularly preferred. By setting the porosity of the anodized film to 20% or more, the thermal diffusion to the aluminum support is sufficiently suppressed, and the effect of increasing the sensitivity is sufficiently obtained. Further, it is preferable that the porosity of the anodized film is 70% or less because the problem of stains in the non-image area is less likely to occur.

[Hydrophilic layer]
In the present invention, a hydrophilic layer having a hydrophilic graft chain is provided on a support having the specific inorganic compound particle layer. The hydrophilic layer in which the hydrophilic graft chain exists refers to the surface on which the hydrophilic graft chain exists. This may be one in which the hydrophilic graft polymer chain is directly bonded to the support surface, or an intermediate layer on which the graft polymer is easily bonded is provided on the support surface, and the hydrophilic polymer is grafted on the layer. It may be what you have.

  Furthermore, the hydrophilic layer in the present invention has a polymer in which a hydrophilic graft polymer chain is bonded to a trunk polymer compound, or a functional group in which a hydrophilic graft polymer chain is bonded to a trunk polymer compound and can be crosslinked. Using the introduced polymer, coating or coating using a composition containing a hydrophilic polymer having a crosslinkable group at the polymer terminal and a crosslinking agent, which is disposed on the support surface by coating or coating crosslinking. Those arranged on the surface of the support by crosslinking are also included.

The hydrophilic polymer used in the present invention is characterized in that the polymer terminal is bonded to the support surface or the support surface layer, and the hydrophilic graft portion is not substantially crosslinked. This structure is characterized in that high mobility can be maintained without restricting the mobility of the polymer portion that exhibits hydrophilicity or being embedded in a strong cross-linked structure. For this reason, it is considered that superior hydrophilicity is expressed as compared with a hydrophilic polymer having a normal crosslinked structure.
The molecular weight of such a hydrophilic graft polymer chain is in the range of 500 to 5,000,000 in terms of weight average molecular weight Mw, the preferred molecular weight is in the range of 1,000 to 1,000,000, and more preferably in the range of Mw 2000 to 500,000.

  In the present invention, (a) a hydrophilic graft polymer chain directly bonded to the support surface or an intermediate layer provided on the support surface is referred to as “surface graft”, and (b) hydrophilic graft When using a polymer chain introduced into a polymer cross-linked membrane structure, it is referred to as a “hydrophilic graft chain-introduced cross-linked hydrophilic layer”. In the present invention, a support or a material provided with an intermediate layer on the support is referred to as a “base material”.

[(A) Method for producing surface graft]
As a method for producing a hydrophilic layer having a hydrophilic group made of a graft polymer on a base material, a method in which the base material and the graft polymer are attached by a chemical bond, and a double bond that can be polymerized based on the base material. There are two methods of polymerizing a compound having a polymer to form a graft polymer.

First, a method for attaching the base material and the graft polymer by chemical bonding will be described.
In this method, a polymer having a functional group that reacts with the substrate at the end or side chain of the polymer is used, and the functional group can be grafted by chemically reacting with the functional group on the substrate surface. The functional group that reacts with the substrate is not particularly limited as long as it can react with the functional group on the substrate surface. For example, a silane coupling group such as alkoxysilane, an isocyanate group, an amino group, a hydroxyl group, Examples thereof include a carboxyl group, a sulfonic acid group, a phosphoric acid group, an epoxy group, an allyl group, a methacryloyl group, and an acryloyl group. Particularly useful compounds as a polymer having a reactive functional group at the terminal or side chain of the polymer are a hydrophilic polymer having a trialkoxysilyl group at the polymer terminal, a hydrophilic polymer having an amino group at the polymer terminal, and a carboxyl group at the polymer terminal. A hydrophilic polymer having an epoxy group at the polymer terminal, and a hydrophilic polymer having an isocyanate group at the polymer terminal.
In addition, the hydrophilic polymer used at this time is not particularly limited as long as it is hydrophilic. Specifically, polyacrylic acid, polymethacrylic acid, polystyrene sulfonic acid, poly-2-acrylamido-2-methyl is used. Mention may be made of propanesulfonic acid and their salts, polyacrylamide, polyvinylacetamide and the like. In addition, a polymer of a hydrophilic monomer used in the following surface graft polymerization or a copolymer containing a hydrophilic monomer can be advantageously used.

  A method of polymerizing a compound having a double bond that can be polymerized from a base material to form a graft polymer is generally called surface graft polymerization. The surface graft polymerization method is a method in which an active species is provided on the surface of a substrate by a method such as plasma irradiation, light irradiation, or heating, and a compound having a polymerizable double bond disposed so as to be in contact with the substrate is polymerized. Refers to the method of bonding with the material.

Any known method described in the literature can be used as the surface graft polymerization method for carrying out the present invention. For example, New Polymer Experiment 10, edited by Polymer Society, 1994, published by Kyoritsu Shuppan Co., Ltd., P135 describes a photograft polymerization method and a plasma irradiation graft polymerization method as surface graft polymerization methods. In addition, the adsorption technique handbook, NTS Co., Ltd., supervised by Takeuchi, 1999.2, p203, p695 describes radiation-induced graft polymerization methods such as γ rays and electron beams. As a specific method of the photograft polymerization method, methods described in JP-A-63-92658, JP-A-10-296895 and JP-A-11-119413 can be used. In the plasma irradiation graft polymerization method and the radiation irradiation graft polymerization method, the literatures described above, Ikada et al, Macromolecules vol. 19, page 1804 (1986), and the like can be applied.
Specifically, a polymer surface such as PET is treated with plasma or electron beam to generate radicals on the surface, and then the active surface is reacted with a monomer having a hydrophilic functional group. A graft polymer surface layer, that is, a surface layer having a hydrophilic group can be obtained.
In addition to the above-mentioned documents, photograft polymerization can be carried out as described in JP-A No. 53-17407 (Kansai Paint) and JP-A No. 2000-212313 (Dainippon Ink). It can also be carried out by applying a photopolymerizable composition to the surface, and then irradiating it with an aqueous radical polymerization compound in contact.

A compound useful for forming a hydrophilic graft polymer chain must have a polymerizable double bond and also have a hydrophilic property. As these compounds, any of these compounds can be used as long as it has a double bond in the molecule, whether it is a hydrophilic polymer, a hydrophilic oligomer, or a hydrophilic monomer. Particularly useful compounds are hydrophilic monomers.
The hydrophilic monomer useful in the present invention is a monomer having a positive charge such as ammonium or phosphonium, or a negative charge or negative charge such as a sulfonic acid group, a carboxyl group, a phosphoric acid group, or a phosphonic acid group. In addition, monomers having a nonionic group such as a hydroxyl group, an amide group, a sulfonamide group, an alkoxy group, or a cyano group may be used. You can also.

In the present invention, specific examples of particularly useful hydrophilic monomers include the following monomers. For example, (meth) acrylic acid or its alkali metal salt and amine salt, itaconic acid or its alkali metal salt and amine salt, allylamine or its hydrohalide salt, 3-vinylpropionic acid or its alkali metal salt and amine salt Vinyl sulfonic acid or its alkali metal salt and amine salt, styrene sulfonic acid or its alkali metal salt and amine salt, 2-sulfoethylene (meth) acrylate, 3-sulfopropylene (meth) acrylate or its alkali metal salt and amine salt 2-acrylamido-2-methylpropanesulfonic acid or its alkali metal salts and amine salts, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate or their salts, 2-dimethyla Noethyl (meth) acrylate or its hydrohalide, 3-trimethylammoniumpropyl (meth) acrylate, 3-trimethylammoniumpropyl (meth) acrylamide, N, N, N-trimethyl-N- (2-hydroxy-3- (Methacryloyloxypropyl) ammonium chloride, etc. can be used. In addition, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide, N-vinylpyrrolidone, N-vinylacetamide, polyoxyethylene glycol mono (meth) ) Acrylate is also useful.

[(B) Preparation Method of Hydrophilic Graft Chain-Introduced Crosslinked Hydrophilic Layer]
The crosslinked hydrophilic layer into which the hydrophilic graft chain of the present invention has been introduced can be generally produced by preparing a graft polymer using a known method as a method for synthesizing a graft polymer and crosslinking it. Specifically, the synthesis of the graft polymer is "graft polymerization and its application" written by Fumio Ide, published in 1977, "Polymer Publishing", and "New Polymer Experiments 2, Polymer Synthesis and Reaction". Edition, Kyoritsu Publishing Co., Ltd. (1995).

The synthesis of the graft polymer is basically as follows: 1. Polymerize the branch monomer from the trunk polymer. 2. Link the branch polymer to the trunk polymer. It can be divided into three methods of copolymerizing a branch polymer with a trunk polymer (macromer method). Any of these three methods can be used to produce the hydrophilic surface in the present invention. In particular, “3. Macromer method” is excellent from the viewpoint of production suitability and control of the film structure. Yes. The synthesis of a graft polymer using a macromer is described in the above-mentioned "New Polymer Experiment 2, Polymer Synthesis / Reaction" edited by Polymer Society of Japan, Kyoritsu Publishing Co., Ltd. 1995. It is also described in detail in Yu Yamashita et al. “Chemical Monomer Chemistry and Industry”, IPC, 1989.
Specifically, according to the method described in the literature, using hydrophilic monomers specifically described as the organic cross-linked hydrophilic layer, such as acrylic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylacetamide and the like. Hydrophilic macromers can be synthesized.

Among the hydrophilic macromers used in the present invention, particularly useful are macromers derived from carboxyl group-containing monomers such as acrylic acid and methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, And sulfonic acid macromers derived from monomers of the salts thereof, amide macromers such as acrylamide and methacrylamide, amide macromers derived from N-vinylcarboxylic acid amide monomers such as N-vinylacetamide and N-vinylformamide, Macromers derived from hydroxyl-containing monomers such as hydroxyethyl methacrylate, hydroxyethyl acrylate, glycerol monomethacrylate, methoxyethyl acrylate, methoxypolyethylene glycol acrylate, polyethylene Macromers derived from alkoxy group or ethylene oxide group-containing monomers such as glycol acrylate. A monomer having a polyethylene glycol chain or a polypropylene glycol chain can also be usefully used as the macromer of the present invention.
Among these macromers, the useful molecular weight is in the range of 400 to 100,000, preferably 1
000 to 50,000, particularly preferably in the range of 1500 to 20,000. Within this range, good hydrophilicity and polymerization reactivity with the copolymerized monomer can be obtained.

  After synthesizing these hydrophilic macromers, one method for preparing a crosslinked hydrophilic layer having a hydrophilic graft chain introduced therein is to copolymerize the hydrophilic macromer with another monomer having a reactive functional group and graft copolymer. In this method, a polymer is synthesized, and then the synthesized graft copolymer and a crosslinking agent that reacts with a reactive functional group of the polymer are coated on a support and reacted by heat to be crosslinked. In addition, as another method, there is a method of synthesizing a graft polymer having a hydrophilic macromer and a photocrosslinkable group or a polymerizable group, applying it on a support and reacting it with light irradiation to form a crosslink. Can be mentioned.

In this way, a hydrophilic layer having a hydrophilic graft polymer chain can be provided on the substrate. The thickness of the hydrophilic layer can be selected depending on the purpose, but generally it is preferably in the range of 0.001 μm to 10 μm, more preferably in the range of 0.01 μm to 5 μm, and most preferably in the range of 0.01 μm to 1 μm.
Even when a transparent resin substrate is used in the present invention, the graft polymer need not completely cover the substrate surface. When the graft polymer is introduced on the surface of the resin substrate, if the graft polymer is introduced in an amount of 10% or more based on the total surface area of the substrate, an effective adhesion improving effect is exhibited. More preferably, the graft polymer is 30% or more, more preferably 60% or more, based on the total surface area of the substrate.

  Among such hydrophilic layers, an alkoxide compound having a hydrophilic graft chain and containing an element selected from Si, Ti, Zr, and Al from the viewpoint of adhesion to adjacent layers and film strength. A hydrophilic layer having a cross-linked structure formed by hydrolysis and condensation polymerization of is preferred, and the hydrophilic layer having such a cross-linked structure is a hydrophilic functional group capable of forming a hydrophilic graft chain with the alkoxide compound. It can form suitably using the compound which has this. Among the alkoxide compounds, Si alkoxides are preferable from the viewpoint of reactivity and availability, and specifically, compounds used for silane coupling agents can be suitably used.

In the present invention, the above-described crosslinked structure formed by hydrolysis and condensation polymerization of the alkoxide compound is appropriately referred to as a sol-gel crosslinked structure.
The hydrophilic layer having such a free hydrophilic graft chain and a sol-gel crosslinked structure preferably contains a hydrophilic polymer compound represented by the following general formula (1), more preferably the following general formula: The hydrophilic coating liquid composition containing the crosslinking component represented by (2) can be prepared, and can be easily formed by coating and drying on the substrate surface.

(Specific hydrophilic polymer represented by general formula (1))
In the present invention, among the specific hydrophilic polymers, those having a structure represented by the following general formula (1) are preferable.

The specific hydrophilic polymer according to the present invention represented by the formula (1) is represented by the structural unit (iii) at at least one of both ends of the polymer unit represented by the structural units (i) and (ii). What is necessary is just to have a silane coupling group, you may have this functional group also at the other terminal, and you may have a functional group which has a hydrogen atom or a polymerization initiating ability.
In the general formula (1), m represents 0, 1 or 2, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or a carbon atom having 1 to 8 carbon atoms. Represents a hydrogen group. Examples of the hydrocarbon group include an alkyl group and an aryl group, and a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms is preferable. Specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group and the like.
R ^{1 to} R ⁶ are preferably a hydrogen atom, a methyl group, or an ethyl group from the viewpoints of effects and availability.

These hydrocarbon groups may further have a substituent.
When the alkyl group has a substituent, the substituted alkyl group is constituted by a bond between a substituent and an alkylene group, and here, a monovalent nonmetallic atomic group excluding hydrogen is used as the substituent. Preferred examples include halogen atoms (-F, -Br, -Cl, -I), hydroxyl groups, alkoxy groups, aryloxy groups, mercapto groups, alkylthio groups, arylthio groups, alkyldithio groups, aryldithio groups, amino groups, N-alkylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, ア ル キ ル -alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkyl Carbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-aryl Acylamino group, ureido group, N ′ Alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N -Arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureate group, N', N'-dialkyl- N-arylureido group, N′-aryl-Ν-alkylureido group, N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl- N-arylureido group, N′-alkyl-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group Aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino Group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group , N- alkyl -N- arylcarbamoyl group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base group (hereinafter referred to as sulfonato group), a Coxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N -Alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N- alkyl -N- arylsulfamoyl group phosphono group (-PO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonato group), a dialkyl phosphono group (-PO ₃ (alkyl) _2), Jiariruhosu Phono group (—PO ₃ (aryl) ₂ ), alkylaryl phosphono group (—PO ₃ ( alkyl) (aryl)), monoalkyl phosphono group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkyl phosphonate group), monoaryl phosphono group (—PO ₃ H (aryl)) ) And its conjugate base group (hereinafter referred to as arylphosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonateoxy group), dialkylphosphonooxy group ( -OPO ₃ (alkyl) _2), diaryl phosphonooxy group _{(-OPO 3 (aryl) 2)} , alkylaryl phosphonooxy group (-OPO (alkyl) (aryl) ), monoalkyl phosphonooxy group (-OPO ₃ H (alkyl)) and its conjugated base group (hereinafter referred to as alkyl phosphonophenyl group), mono Reel phosphonooxy group (-OPO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as aryl phosphite Hona preparative group), Moruhoruno group, a cyano group, a nitro group, an aryl group, an alkenyl group, an alkynyl group include It is done.

Specific examples of the alkyl group in these substituents include the above-described alkyl groups, and specific examples of the aryl group include phenyl group, biphenyl group, naphthyl group, tolyl 2 group, xylyl group, mesityl group, cumenyl group. Group, chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methyl Aminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl , It can be exemplified cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl phenyl group, a phosphonophenyl phenyl group. Examples of alkenyl groups include vinyl, 1-propenyl, 1-butenyl, cinnamyl, 2-chloro-1-ethenyl, etc. Examples of alkynyl include ethynyl, 1-butenyl, A propynyl group, a 1-butynyl group, a trimethylsilylethynyl group, etc. are mentioned. Examples of G ¹ in the acyl group (G ¹ CO—) include hydrogen and the above alkyl groups and aryl groups.

  Among these substituents, more preferred are halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N-dialkyls. Amino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfamoy Group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkyl phosphono group, diaryl phosphono group, monoalkyl phosphono group, alkyl phosphonate group, monoaryl phosphono group, aryl phosphonate group Group, phosphonooxy group, phosphonatooxy group, aryl group, and alkenyl group.

  On the other hand, examples of the alkylene group in the substituted alkyl group include divalent organic residues obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Can be a straight chain having 1 to 12 carbon atoms, a branched chain having 3 to 12 carbon atoms, and a cyclic alkylene group having 5 to 10 carbon atoms. Preferable specific examples of the substituted alkyl group obtained by combining the substituent and the alkylene group include chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, methoxyethoxyethyl group, allyl group. Oxymethyl group, phenoxymethyl group, methylthiomethyl, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N- Phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxyethyl group, 2-oxypropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxy Carbonyl butyl group,

  Chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoyl Methyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (Phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, Torilho Phonatohexyl group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group and the like.

L ¹ and L ² represent a single bond or an organic linking group. Here, the organic linking group refers to a polyvalent linking group composed of a nonmetallic atom, and specifically includes 1 to 60 carbon atoms, 0 to 10 nitrogen atoms, and 0 to 50 carbon atoms. It consists of up to 1 oxygen atom, 1 to 100 hydrogen atoms, and 0 to 20 sulfur atoms. More specific examples of the linking group include the following structural units or those formed by combining them.

L ³ represents a single bond or an organic linking group. Here, the organic linking group refers to a polyvalent linking group composed of a nonmetallic atom, and specific examples thereof include those similar to the above L ¹ and L ² . Among them, particularly preferred structure, - (CH _{2) n} -S- can be mentioned (n is an integer of 1 to 8).

Y ¹ and Y ² each independently represent —N (R ⁷ ) (R ⁸ ), —OH, —NHCOR ⁷ , —COR ⁷ , —CO ₂ M or SO ₃ M, where R ⁷ , R ⁸ each independently represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms. In addition, with respect to —N (R ⁷ ) (R ⁸ ), R ⁷ and R ⁸ may be bonded to each other to form a ring, and the formed ring is a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. It may be a heterocycle containing an atom. R ⁷ and R ⁸ may further have a substituent, and the substituents that can be introduced here are the same as those mentioned as the substituents that can be introduced when R ^{1 to} R ⁶ are alkyl groups. Can be listed.

Specific examples of R ⁷ and R ⁸ include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, isopropyl group, isobutyl group, s-butyl group, and t-butyl. Preferred examples include a group, an isopentyl group, a neopentyl group, a 1-methylbutyl group, an isohexyl group, a 2-ethylhexyl group, a 2-methylhexyl group, and a cyclopentyl group.
Examples of M include a hydrogen atom; an alkali metal such as lithium, sodium and potassium; an alkaline earth metal such as calcium and barium; or an onium such as ammonium, iodonium and sulfonium.
Further, such a specifically as _{^{Y 1, Y 2, -NHCOCH 3}} , -NH 2, -COOH, -SO 3 - NMe 4 +, a morpholino group, etc. are preferable.

  x and y represent a composition ratio when x + y = 100, x: y represents a range of 100: 0 to 1:99, and a range of 100: 0 to 5:95 is more preferable.

  The molecular weight of the specific hydrophilic polymer is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and most preferably 1,000 to 30,000.

  Specific examples (1-1) to (1-23) of the specific hydrophilic polymer that can be suitably used in the present invention are shown below, but the present invention is not limited thereto.

<Synthesis method>
The specific hydrophilic polymer according to the present invention includes a radical polymerizable monomer represented by the following structural units (i) and (ii) and a silane having chain transfer ability in the radical polymerization represented by the following structural unit (iii) It can be synthesized by radical polymerization using a coupling agent. Since the silane coupling agent has chain transfer ability, it is possible to synthesize a polymer in which a silane coupling group is introduced at the end of the polymer main chain in radical polymerization.
Although this reaction mode is not particularly limited, bulk reaction, solution reaction, suspension reaction, etc. may be performed in the presence of a radical polymerization initiator or irradiation with a high-pressure mercury lamp.

In addition, in the polymerization reaction, the amount of the structural unit represented by (iii) is controlled, and the homopolymerization of the structural unit with the structural unit (i) or (ii) is effectively suppressed. A polymerization method using an addition method, a sequential addition method, or the like is preferably performed.
The reaction ratio of the structural units (i) and (ii) to the structural unit (iii) is not particularly limited, but the structural units (i) and (ii) are 0 with respect to 1 mol of the structural unit (iii). From the viewpoint of suppressing side reactions and improving the yield of the hydrolyzable silane compound, the range of 1 to 45 mol is more preferable, and the range of 5 to 40 mol is preferable. Most preferred.

In the structural units (i), (ii), and (iii), R ^{1 to} R ⁶ , L ^{1 to} L ³ , Y ¹ , Y ^2, and m are as defined in the general formula (1). These compounds are commercially available and can be easily synthesized.

  Any of the conventionally known methods can be used as the radical polymerization method for synthesizing the specific hydrophilic polymer. Specifically, general radical polymerization methods include, for example, New Polymer Experimental Science 3, Polymer Synthesis and Reaction 1 (Edited by the Society of Polymer Science, Kyoritsu Shuppan), New Experimental Chemistry Course 19, Polymer Chemistry (I) (The Chemical Society of Japan, Maruzen), Materials Engineering, Synthetic Polymer Chemistry (Tokyo Denki University Press), etc., can be applied.

  The specific hydrophilic polymer may be a copolymer with another monomer as described later. Examples of other monomers used include acrylic esters, methacrylic esters, acrylamides, methacrylamides, vinyl esters, styrenes, acrylic acid, methacrylic acid, acrylonitrile, maleic anhydride, maleic imide, etc. A well-known monomer is also mentioned. By copolymerizing such monomers, various physical properties such as film forming property, film strength, hydrophilicity, hydrophobicity, solubility, reactivity, and stability can be improved.

Specific examples of acrylic esters include methyl acrylate, ethyl acrylate, (n- or i-) propyl acrylate, (n-, i-, sec- or t-) butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, Dodecyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxypentyl acrylate, cyclohexyl acrylate, allyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, chloro Benzyl acrylate, hydroxybenzyl acrylate, hydroxyphenethyl acrylate, dihydroxyphene Chill acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyphenyl acrylate, chlorophenyl acrylate, sulfamoylphenyl acrylate, 2- (hydroxyphenyl carbonyloxy) ethyl acrylate.

  Specific examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, (n- or i-) propyl methacrylate, (n-, i-, sec- or t-) butyl methacrylate, amyl methacrylate, 2-ethylhexyl methacrylate, Dodecyl methacrylate, chloroethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxypentyl methacrylate, cyclohexyl methacrylate, allyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, benzyl methacrylate, methoxybenzyl methacrylate, chloro Benzyl methacrylate, hydroxybenzyl methacrylate, hydroxy E phenethyl methacrylate, dihydroxyphenethyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, phenyl methacrylate, hydroxyphenyl methacrylate, chlorophenyl methacrylate, sulfamoylphenyl methacrylate, 2- (hydroxyphenyl carbonyloxy) ethyl methacrylate.

  Specific examples of acrylamides include acrylamide, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N-benzylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, and N-tolylacrylamide. N- (hydroxyphenyl) acrylamide, N- (sulfamoylphenyl) acrylamide, N- (phenylsulfonyl) acrylamide, N- (tolylsulfonyl) acrylamide, N, N-dimethylacrylamide, N-methyl-N-phenylacrylamide , N-hydroxyethyl-N-methylacrylamide and the like.

  Specific examples of methacrylamides include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-propylmethacrylamide, N-butylmethacrylamide, N-benzylmethacrylamide, N-hydroxyethylmethacrylamide, N -Phenylmethacrylamide, N-tolylmethacrylamide, N- (hydroxyphenyl) methacrylamide, N- (sulfamoylphenyl) methacrylamide, N- (phenylsulfonyl) methacrylamide, N- (tolylsulfonyl) methacrylamide, N , N-dimethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-methylmethacrylamide and the like.

Specific examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate and the like.
Specific examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, propyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, dimethoxy styrene. Chlorostyrene, dichlorostyrene, bromostyrene, iodostyrene, fluorostyrene, carboxystyrene and the like.

  The proportion of these other monomers used in the synthesis of the copolymer needs to be an amount sufficient to improve various physical properties, but if the proportion is too large, it functions as a support for a lithographic printing plate. Is insufficient. Accordingly, the preferred total proportion of other monomers in the specific hydrophilic polymer is preferably 80% by mass or less, and more preferably 50% by mass or less.

(Crosslinking component represented by general formula (2))
The hydrophilic surface according to the present invention may be one in which the crosslinkable group in the specific hydrophilic polymer is chemically bonded directly to a functional group such as -Al ³⁺ or -OH group on the surface of the specific aluminum substrate. Alternatively, a hydrophilic coating solution containing a specific hydrophilic polymer is prepared, applied to the substrate surface, and dried to form a crosslinked structure (sol-gel crosslinked structure) by hydrolysis and condensation polymerization of the crosslinking group. It may be what you did.
In forming the sol-gel cross-linked structure, it is preferable to mix a specific hydrophilic polymer and a cross-linking component represented by the following general formula (2), and apply and dry on the substrate surface. The crosslinking component represented by the following general formula (2) is a compound having a polymerizable functional group in its structure and functioning as a crosslinking agent, and by condensation polymerization with the specific hydrophilic polymer. A strong film having a crosslinked structure is formed.

In the general formula (2), R ⁹ represents a hydrogen atom, an alkyl group or an aryl group, R ¹⁰ represents an alkyl group or an aryl group, X represents Si, Al, Ti or Zr, and m is 0 to 2. Represents an integer.
When R ⁹ and R ¹⁰ represent an alkyl group, the number of carbon atoms is preferably 1 to 4. The alkyl group or aryl group may have a substituent, and examples of the substituent that can be introduced include a halogen atom, an amino group, and a mercapto group.
This compound is a low molecular compound and preferably has a molecular weight of 1000 or less.

Specific examples of the crosslinking component represented by the general formula (2) are given below, but the present invention is not limited thereto.
When X is Si, that is, the hydrolyzable compound containing silicon includes, for example, trimethoxysilane, triethoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxy Silane, ethyltriethoxysilane, propyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, γ-chloropropyltriethoxysilane, γ-mercaptopropyltri Methoxysilane, γ-mercaptopropyltriethoxysilane, γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, diph Alkenyl dimethoxysilane, mention may be made of diphenyl diethoxy silane.
Among these, tetramethoxysilane, tetraethoxysilane, methyltolumethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxy are particularly preferable. Examples include silane, diphenyldimethoxysilane, diphenyldiethoxysilane, and the like.

In addition, when X is Al, that is, examples of those containing aluminum in the hydrolyzable compound include trimethoxy aluminate, triethoxy aluminate, tripropoxy aluminate, tetraethoxy aluminate and the like. it can.
When X is Ti, i.e., those containing titanium include, for example, trimethoxy titanate, tetramethoxy titanate, triethoxy titanate, tetraethoxy titanate, tetrapropoxy titanate, chlorotrimethoxy titanate, chlorotriethoxy titanate, ethyl triethoxy titanate. Examples thereof include methoxy titanate, methyl triethoxy titanate, ethyl triethoxy titanate, diethyl diethoxy titanate, phenyl trimethoxy titanate, and phenyl triethoxy titanate.
In the case where X is Zr, that is, those containing zirconium include, for example, zirconates corresponding to the compounds exemplified as those containing titanium.

(Formation of hydrophilic surface)
<Preparation of hydrophilic coating solution>
In preparing a hydrophilic coating liquid composition containing the specific hydrophilic polymer, the content of the specific hydrophilic polymer is preferably 10% by mass or more and less than 50% by mass in terms of solid content. Within this range, good hydrophilicity and film properties can be obtained.

  In addition, when the crosslinking component is added to the preparation of the hydrophilic coating liquid composition which is a preferred embodiment, the crosslinking component is 5 mol% or more based on the silane coupling group in the specific hydrophilic polymer, The amount is preferably 10 mol% or more. The upper limit of the amount of crosslinking component added is not particularly limited as long as it can be sufficiently crosslinked with the hydrophilic polymer, but when added excessively, the produced hydrophilic surface becomes sticky due to the crosslinking component not involved in crosslinking. there is a possibility.

  An organic-inorganic composite produced by dissolving a hydrophilic polymer having a silane coupling group at its end, preferably, further dissolving a crosslinking component in a solvent and thoroughly stirring these components to cause polycondensation. The body sol liquid becomes the hydrophilic coating liquid according to the present invention, whereby a surface hydrophilic layer having high hydrophilicity and high film strength is formed. In the preparation of the organic-inorganic composite sol solution, it is preferable to use an acidic catalyst, a basic catalyst, or a metal chelate compound as a catalyst in order to promote hydrolysis and polycondensation reaction. Such catalysts are essential when trying to obtain. In the present invention, it is particularly preferable to use a metal chelate compound as a catalyst.

  As the acidic catalyst or the basic catalyst, an acid or a basic compound is used as it is, or a catalyst in which it is dissolved in a solvent such as water or alcohol is used. The concentration at the time of dissolving in the solvent is not particularly limited, and may be appropriately selected according to the characteristics of the acid or basic compound used, the desired content of the catalyst, etc. Condensation rate tends to increase. However, when a basic catalyst with a high concentration is used, a precipitate may be generated in the sol solution. Therefore, when a basic catalyst is used, the concentration is preferably 1 N or less in terms of concentration in an aqueous solution.

  The type of acidic catalyst or basic catalyst is not particularly limited, but it is necessary to use a highly concentrated catalyst.

In some cases, a catalyst composed of an element that hardly remains in the coating film after drying is preferable.
Specifically, the acidic catalyst is represented by hydrogen halide such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, carboxylic acid such as formic acid or acetic acid, and its RCOOH. Examples thereof include substituted carboxylic acids in which R in the structural formula is substituted with other elements or substituents, sulfonic acids such as benzenesulfonic acid, etc., and basic catalysts include ammoniacal bases such as aqueous ammonia and amines such as ethylamine and aniline Etc.

The metal chelate compound used in the present invention is represented by the following general formula (3) or (4).

In formulas (3) and (4), M ₁ represents Al, and M ₂ represents Ti or Zr.
R ¹¹ and R ¹² each represent an alkyl group having 1 to 6 carbon atoms. Specific examples include an ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, and phenyl group.
R ¹³ represents the same alkyl group having 1 to 6 carbon atoms as that described above for R ¹¹ and R ¹² , or an alkoxy group having 1 to 16 carbon atoms. Examples of such alkoxy groups include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, sec-butoxy, lauryl, stearyl and the like.
p represents an integer of 0 to 2, and q represents an integer of 0 to 3.

  Specific examples of such metal chelate compounds include, for example, tri-n-butoxyethyl acetoacetate zirconium, di-n-butoxybis (ethyl acetoacetate) zirconium, n-butoxy tris (ethyl acetoacetate) zirconium, tetrakis (n Zirconium chelate compounds such as propylacetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium , Titanium chelate compounds such as diisopropoxy bis (acetylacetone) titanium; tris (acetylacetone) aluminum, diisopro Xylethylacetoacetate aluminum, diisopropoxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum, Examples thereof include aluminum chelate compounds such as monoacetylacetonate and bis (ethylacetoacetate) aluminum. Among these metal chelate compounds, preferred are tri-n-butoxyethyl acetoacetate zirconium, diisobroxoxybis (acetylacetonato) titanium, tris (acetylacetone) aluminum, diisopropoxyethylacetoacetate aluminum, tris (ethylacetate). Acetate) aluminum. These metal chelate compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  The addition amount of the metal chelate compound according to the present invention is usually about 0.01 to 15% by mass, preferably 0.1 to 15% by mass, and preferably 0.1 to 15% by mass with respect to the total solid content of the hydrophilic coating solution. 10 mass% is more preferable.

  The hydrophilic coating solution can be prepared by dissolving the hydrophilic polymer having a silane coupling group at the end, preferably a crosslinking component in a solvent such as ethanol, and then adding the catalyst as desired and stirring. The reaction temperature is from room temperature to 80 ° C., and the reaction time, that is, the time for which stirring is continued is preferably in the range of 1 to 72 hours. By this stirring, hydrolysis and polycondensation of both components are advanced, and organic inorganic A composite sol solution can be obtained.

  The solvent used in preparing the hydrophilic polymer and preferably a hydrophilic coating liquid composition containing a crosslinking component is not particularly limited as long as it can uniformly dissolve and disperse them. Aqueous solvents such as methanol, ethanol and water are preferred.

  As described above, the preparation of the organic-inorganic composite sol liquid (hydrophilic coating liquid composition) for forming the hydrophilic surface according to the present invention utilizes the sol-gel method. For the sol-gel method, Sakuo Sakuo “Science of Sol-Gel Method”, Agne Jofusha (published) (1988), Satoshi Hirashima “Functional Thin Film Formation Technology by the Latest Sol-Gel Method” General Technology Center (Published) (1992) and the like, and the methods described therein can be applied to the preparation of the hydrophilic coating liquid composition according to the present invention.

  As long as the effects of the present invention are not impaired, various additives can be used in the hydrophilic coating liquid composition according to the present invention depending on the purpose. For example, a surfactant can be added to improve the uniformity of the coating solution.

A hydrophilic layer can be formed by applying and drying the hydrophilic coating solution composition prepared as described above on a support having the specific inorganic compound particle layer. The thickness of the hydrophilic layer can be selected depending on the purpose, but is generally in the range of 0.01 to 3.0 g / m ² , preferably 0.01 to 1.0 g / m ^{2 in} terms of the coating amount after drying. Is in the range of ² , more preferably in the range of 0.03 to 1.0 g / m ² . Within this range, a good hydrophilic effect is exhibited without causing a decrease in sensitivity or film strength.

[Image recording layer]
Next, the image recording layer in the planographic printing plate precursor according to the invention will be described in detail.
The lithographic printing plate precursor according to the present invention contains (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound on a support, and includes printing ink, dampening water, or both. It has a removable image recording layer.
Hereinafter, each component constituting the image recording layer will be described in detail.

[(A) Infrared absorber]
The image recording layer in the present invention contains an infrared absorbing agent in order to enable efficient image formation using a laser emitting infrared light of 760 to 1200 nm as a light source. The infrared absorber has a function of converting absorbed infrared rays into heat. Due to the heat generated at this time, a polymerization initiator (radical generator) described later is thermally decomposed to generate radicals. Such an infrared absorber used in the present invention is a dye or pigment having an absorption maximum at a wavelength of 760 to 1200 nm.

As the dye, 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, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.
Preferred dyes include, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, The methine dyes described in JP-A-58-181690 and JP-A-58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, Naphthoquinone dyes described in JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, and the like, squarylium dyes described in JP-A-58-112792, and the like; And cyanine dyes described in British Patent No. 434,875.

  In addition, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also suitable. ) Pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59- No. 41363, 59-84248, 59-84249, 59-146063, 59-146061, and pyrine compounds described in JP-A-59-216146. In US Pat. No. 4,283,475, the pentamethine thiopyrylium salt, etc., and Japanese Patent Publication Nos. 5-13514 and 5-19702 are disclosed. Pyrylium compounds 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, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferable, and one particularly preferable example is a cyanine dye represented by the following general formula (i).

In formula (i), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below.

X ² in the general formula (i) represents an oxygen atom, a nitrogen atom, or a sulfur atom, and L ¹ is a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or carbon containing a hetero atom. A hydrocarbon group having 1 to 12 atoms is shown. Here, the hetero atom represents N, S, O, a halogen atom, or Se. Xa ^- the Za described later ^- is defined as for, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom. Ph represents a phenyl group.

R ¹ and R ² in the general formula (i) each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording 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 ring or It is particularly preferable that a 6-membered ring is formed.

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. However, Za ⁻ is not necessary when the cyanine dye represented by formula (i) has an anionic substituent in its structure and neutralization of charge is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion from the viewpoint of storage stability of the recording layer coating solution, and particularly preferably a perchlorate ion, a hexagonal ion. Fluorophosphate ions and aryl sulfonate ions.

Specific examples of cyanine dyes represented by formula (i) that can be suitably used in the present invention include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. Can do.
Other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057.
Furthermore, the infrared absorber is preferably water-soluble, but when it is water-insoluble, it can be added by a method such as dispersion or dissolution in a mixed solvent.

  Examples of the pigment used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technology Association, published in 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “Printing Ink Technology”, CMC Publishing, 1984) can be used.

  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. Within this range, good stability of the pigment dispersion in the image recording layer coating solution and good uniformity of the image recording layer can be obtained.

  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).

  The addition of these infrared absorbers to the image recording layer is preferably made the minimum necessary amount in order to suppress side effects that inhibit the polymerization reaction.

  These infrared absorbers are added in a proportion of 0.001 to 50% by mass, preferably 0.005 to 30% by mass, particularly preferably 0.01 to 10% by mass, based on the total solid content of the image recording layer. Can do. Within this range, high sensitivity can be obtained without adversely affecting the uniformity and film strength of the image recording layer.

  Among these infrared absorbers described above, a preferable dye is a cyanine dye represented by the general formula (i).

[(B) polymerization initiator]
The polymerization initiator used in the present invention is a compound that generates radicals by light, heat, or both, and initiates and accelerates polymerization of a compound having a polymerizable unsaturated group. As the polymerization generator that can be used in the present invention, a known thermal polymerization initiator, a compound having a bond with a small bond dissociation energy, a photopolymerization initiator, or the like can be used, and a radical that is suitably used in the present invention is generated. The compound to be used refers to a compound that initiates and accelerates polymerization of a compound having a polymerizable unsaturated group by generating radicals by thermal energy. As the thermal radical generator according to the present invention, a known polymerization initiator, a compound having a bond with a small bond dissociation energy, or the like can be appropriately selected and used. Moreover, the compound which generate | occur | produces a radical can be used individually or in combination of 2 or more types.
Examples of the compound that generates radicals include organic halogenated compounds, carbonyl compounds, organic peroxide compounds, azo polymerization initiators, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boric acid compounds, disulfonic acid compounds, Examples include oxime ester compounds and onium salt compounds.

  Specific examples of the organic halogenated compound include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Examined Patent Publication No. 46-4605, JP-A 48-36281, JP-A 55-32070, JP-A 60-239736, JP-A 61-169835, JP-A 61-169837, JP-A 62-58241, JP 62-212401, JP-A 63-70243, JP-A 63-298339, P. Examples include compounds described in Hutt “Journal of Heterocyclic Chemistry” 1 (No 3), (1970), and in particular, an oxazole compound substituted with a trihalomethyl group: S-triazine compound.

  More preferably, an s-triazine derivative having at least one mono, di, or trihalogen-substituted methyl group bonded to the s-triazine ring, specifically, for example, 2,4,6-tris (monochloromethyl)- s-triazine, 2,4,6-tris (dichloromethyl) -s-triazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methyl-4,6-bis (trichloromethyl)- s-triazine, 2-n-propyl-4,6-bis (trichloromethyl) -s-triazine, 2- (α, α, β-trichloroethyl) -4,6-bis (trichloromethyl) -s-triazine 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, -(3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- [1 -(P-methoxyphenyl) -2,4-butadienyl] -4,6-bis (trichloromethyl) -s-triazine, 2-styryl-4,6-bis (trichloromethyl) -s-triazine, 2- ( p-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (pi-propyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p -Tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-natoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2-pheni Thio-4,6-bis (trichloromethyl) -s-triazine, 2-benzylthio-4,6-bis (trichloromethyl) -s-triazine, 2,4,6-tris (dibromomethyl) -s-triazine, 2,4,6-tris (tribromomethyl) -s-triazine, 2-methyl-4,6-bis (tribromomethyl) -s-triazine, 2-methoxy-4,6-bis (tribromomethyl) -S-triazine and the like.

  Examples of the carbonyl compound include benzophenone, Michler ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone and other benzophenone derivatives, 2,2-dimethoxy- 2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl- (p-isopropylphenyl) ketone, 1- Hydroxy-1- (p-dodecylphenyl) ketone, 2-methyl- (4 ′-(methylthio) phenyl) -2-morpholino-1-propanone, 1,1,1-trichloromethyl- (p-butylphenyl) Acetophenone derivatives such as ketones, thioxanthone derivatives such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, p- Examples thereof include benzoic acid ester derivatives such as ethyl dimethylaminobenzoate and ethyl p-diethylaminobenzoate.

  As the azo compound, for example, an azo compound described in JP-A-8-108621 can be used.

  Examples of the organic peroxide compound include trimethylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butyl). Peroxy) cyclohexane, 2,2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydro Peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tert-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, , 5-Oxanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxy Dicarbonate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, tert-butyl peroxyoctanoate, tert-butyl peroxylaurate, tersyl carbonate, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4 '-Tetra- (t-hexylperoxycarbonyl) benzophenone, 3,3', 4,4'-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate) , Carbonyldi (t-hexylperoxydihydrogen diphthalate) and the like.

  Examples of the metallocene compound include JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, JP-A-2-4705, Various titanocene compounds described in JP-A-5-83588, such as di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, Di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di- -Cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-penta Fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4,6-trifluoropheny -1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4 , 5,6-pentafluorophen-1-yl, iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109, and the like.

Examples of the hexaarylbiimidazole compound include Japanese Patent Publication No. 6-29285, U.S. Pat. Nos. 3,479,185, 4,311,783, and 4,622.
Various compounds described in each specification of No. 286, specifically, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′- Bis (o-bromophenyl)) 4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole Imidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (m-methoxyphenyl) bididazole, 2,2′-bis (o, o′-dichlorophenyl) -4, 4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o- Methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole and the like.

  Examples of the organic borate compounds include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, and JP-A-9-188710. 2000-131837, Japanese Patent Application Laid-Open No. 2002-107916, Japanese Patent No. 2764769, Japanese Patent Application Laid-Open No. 2002-116539, and Kunz, Martin “Rad Tech'98. Proceeding April 19-22, 1998, Chicago”, etc. Organoboron salts described in JP-A-6-157623, JP-A-6-175564, JP-A-6-175561, and organic boron oxosulfonium complexes, No. 175554, JP-A-6-175553 Organoboron iodonium complexes described in JP-A-9-188710, organoboron phosphonium complexes described in JP-A-9-348710, JP-A-7-128785, JP-A-7-140589, JP-A-7- Specific examples include organoboron transition metal coordination complexes such as those described in Japanese Patent No. 306527 and Japanese Patent Laid-Open No. 7-292014.

  Examples of the disulfone compound include compounds described in JP-A Nos. 61-166544 and 2002-328465.

Examples of the oxime ester compounds include JCS Perkin II (1979) 1653-1660), JCS
Perkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, compounds described in JP 2000-66385 A, compounds described in JP 2000-80068 A, and the like. Is the following compound.

  Examples of the onium salt compound include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in U.S. Pat. No. 4,069,055, ammonium salts described in JP-A-4-365049, U.S. Pat. No. 4,069, No. 055, No. 4,069,056, phosphonium salts described in European Patent Nos. 104 and 143, U.S. Pat. Nos. 339,049 and 410,201, JP -150848, JP-A-2-296514, iodonium salts, European Patent Nos. 370,693, 390,214, 233,567, 297,443, 297,442, U.S. Pat.Nos. 4,933,377, 161,811, 410,201, 339,049, 4,760,013, 4,734,4 No. 44, No. 2,833,827, German Patent Nos. 2,904,626, 3,604,580, and 3,604,581, the sulfonium salts described in J. Pat. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), and onium salts such as arsonium salts.

In particular, from the viewpoint of reactivity and stability, the above oxime ester compounds, diazonium salts, iodonium salts, and sulfonium salts are exemplified. In the present invention, these onium salts function not as acid generators but as ionic radical polymerization initiators.
The onium salts suitably used in the present invention are onium salts represented by the following general formulas (RI-I) to (RI-III).

In the formula (RI-I), Ar ₁₁ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include alkyl groups having 1 to 12 carbon atoms and carbon numbers. 1-12 alkenyl group, C1-C12 alkynyl group, C1-C12 aryl group, C1-C12 alkoxy group, C1-C12 aryloxy group, halogen atom, C1-C1 12 alkylamino groups, C1-C12 dialkylamino groups, C1-C12 alkylamide groups or arylamide groups, carbonyl groups, carboxyl groups, cyano groups, sulfonyl groups, C1-C12 thioalkyl groups And a thioaryl group having 1 to 12 carbon atoms. Z ₁₁ ^- represents a monovalent anion, a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, a sulfate ion, stability From the surface, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, and sulfinate ion are preferable.

In the formula (RI-II), Ar ₂₁ and Ar ₂₂ each independently represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents have 1 to 12 carbon atoms. Alkyl group, alkenyl group having 1 to 12 carbon atoms, alkynyl group having 1 to 12 carbon atoms, aryl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, aryloxy group having 1 to 12 carbon atoms, halogen atom , C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon number 1 -12 thioalkyl group and C1-C12 thioaryl group are mentioned. Z ₂₁ ^- represents a monovalent anion, a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, sulfate ion, a carboxylic acid ion From the viewpoints of stability and reactivity, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, and carboxylate ions are preferable.

In the formula (RI-III), R ₃₁ , R ₃₂ , and R ₃₃ each independently represent an aryl group having 20 or less carbon atoms, an alkyl group, an alkenyl group, or an alkynyl group that may have 1 to 6 substituents. In view of reactivity and stability, an aryl group is desirable. Preferred substituents include alkyl groups having 1 to 12 carbon atoms, alkenyl groups having 1 to 12 carbon atoms, alkynyl groups having 1 to 12 carbon atoms, aryl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, C1-C12 aryloxy group, halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl Group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms. Z ₃₁ ^- represents a monovalent anion, a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, sulfate ion, a carboxylic acid ion From the viewpoints of stability and reactivity, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable. In particular, the carboxyl described in JP-A-2001-343742 is preferable. Acid ions, more preferably carboxylate ions described in JP-A No. 2002-148790 are preferred.

  Specific examples of the polymerization initiator that can be applied to the present invention are listed below, but are not limited thereto.

  These polymerization initiators are added in a proportion of 0.1 to 50% by mass, preferably 0.5 to 30% by mass, particularly preferably 1 to 20% by mass, based on the total solid content constituting the image recording layer. Can do. Within this range, good sensitivity and good stain resistance of the non-image area during printing can be obtained. These polymerization initiators may be used alone or in combination of two or more. Moreover, these polymerization initiators may be added to the same layer as other components, or another layer may be provided and added thereto.

[(C) Polymerizable compound]
The polymerizable compound used in the image recording layer in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and a compound having at least one terminal ethylenically unsaturated bond, preferably two or more. Chosen from. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, isocyanuric acid ethylene oxide (EO) Modified triacrylates, polyester acrylate oligomers, isocyanuric acid EO modified triacrylates, and the like.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

  Examples of other esters include aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, JP-A-59- Those having an aromatic skeleton described in JP-A No. 5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

  Further, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable. Specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinylurethane compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (A) to a polyisocyanate compound having two or more isocyanate groups Etc.

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (A)
(However, R ₄ and R ₅ represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56- Urethane compounds having an ethylene oxide skeleton described in Japanese Patent No. 17654, Japanese Patent Publication No. 62-39417, and Japanese Patent Publication No. 62-39418 are also suitable. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, it is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. In addition, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid compounds described in JP-A-2-25493 are also included. Can be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

About these polymerizable compounds, the details of usage such as the structure, single use or combination, addition amount and the like can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image portion, that is, the cured film, those having three or more functionalities are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrene compound, vinyl ether type). A method of adjusting both sensitivity and strength by using a compound) is also effective.
In addition, the compatibility and dispersibility with other components in the image recording layer (for example, a binder polymer, a polymerization initiator, a colorant, etc.) are important factors in selecting and using the polymerizable compound, For example, the compatibility may be improved by using a low-purity compound or using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving adhesion to a support or an overcoat layer described later.

  The polymerizable compound is used in the image recording layer in an amount of preferably 5 to 80% by mass, more preferably 25 to 75% by mass. These may be used alone or in combination of two or more. In addition, the usage of the polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface adhesiveness, etc. The layer construction and coating method such as undercoating and overcoating can also be carried out.

[Other components of image recording layer]
In the image recording layer in the present invention, components other than the above (A), (B), (C), for example, binder polymer, surfactant, colorant, print-out agent, polymerization inhibitor (thermal polymerization inhibitor). Higher fatty acid derivatives, plasticizers, inorganic fine particles, low molecular weight hydrophilic compounds, and the like.

<Binder polymer>
In the present invention, a binder polymer can be used for improving the film characteristics and on-press developability of the image recording layer. A conventionally well-known thing can be used as a binder polymer without a restriction | limiting, The linear organic polymer which has film property is preferable. Examples of such binder polymers include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac phenolic resins, polyester resins, and synthetic rubbers. And natural rubber.

  The binder polymer preferably has crosslinkability in order to improve the film strength of the image area. In order to impart crosslinkability to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization or may be introduced by a polymer reaction.

  Examples of the polymer having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-butadiene and poly-1,4-isoprene.

  Examples of polymers having ethylenically unsaturated bonds in the side chain of the molecule are polymers of esters or amides of acrylic acid or methacrylic acid, at least of the residue of the ester or amide (-COOR or CONHR R) Mention may be made of polymers having some ethylenically unsaturated bonds.

Examples of the residue (the R) having an ethylenically unsaturated _{bond, - (CH 2) n CR} 1 = CR 2 R 3, - (CH 2 O) n CH 2 CR 1 = CR 2 R 3, - _{(CH 2 CH 2 O) n} CH 2 CR 1 = CR 2 R 3, - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, - (CH 2) n -O-CO —CR ¹ ═CR ² R ³ and (CH ₂ CH ₂ O) ₂ —X (wherein R ^{1 to} R ³ are each a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms, an aryl group, and alkoxy. R ¹ and R ² or R ³ may be bonded to each other to form a ring, n represents an integer of 1 to 10. X represents a dicyclopentadienyl residue. Represents a group).

Specific examples of the ester residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ O—CH ₂ CH═CH ₂ , —CH ₂ C (CH ₃ ) ═CH ₂ , —CH ₂ CH═CH— _{C 6 H 5, -CH 2 CH} 2 OCOCH = CH-C 6 H 5, -CH 2 CH 2 OCOC (CH 3) = CH 2, -CH 2 CH 2 OCOCH = CH 2, -CH 2 CH 2 -NHCOO -CH ₂ CH = CH ₂ and CH ₂ CH (wherein, X represents a dicyclopentadienyl residue.) ₂ O-X and the like.
Specific examples of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (wherein Y
Represents a cyclohexene residue. ), —CH ₂ CH ₂ —OCO—CH═CH ₂ .

  The binder polymer having crosslinkability, for example, has a free radical (polymerization initiation radical or a growth radical in the polymerization process of the polymerizable compound) added to the crosslinkable functional group, and the polymerization chain of the polymerizable compound is formed directly between the polymers. Through addition polymerization, a cross-link is formed between the polymer molecules and cured. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded together, thereby causing cross-linking between polymer molecules. Forms and cures.

  The content of the crosslinkable group in the binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1.0, per 1 g of the binder polymer. -7.0 mmol, most preferably 2.0-5.5 mmol. Within this range, good sensitivity and good storage stability can be obtained.

Further, from the viewpoint of improving the on-press developability of the image recording layer unexposed portion, the binder polymer preferably has high solubility or dispersibility in ink and / or fountain solution.
In order to improve solubility or dispersibility in ink, the binder polymer is preferably oleophilic, and in order to improve solubility or dispersibility in dampening water, the binder polymer is hydrophilic. Is preferred. Therefore, in the present invention, it is also effective to use a lipophilic binder polymer and a hydrophilic binder polymer in combination.

  Examples of hydrophilic binder polymers include hydroxy groups, carboxyl groups, carboxylate groups, hydroxyethyl groups, polyoxyethyl groups, hydroxypropyl groups, polyoxypropyl groups, amino groups, aminoethyl groups, aminopropyl groups, and ammonium. Preferred are those having a hydrophilic group such as a group, an amide group, a carboxymethyl group, a sulfonic acid group, and a phosphoric acid group.

  Specific examples include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and their salts, Polymethacrylic acids and their salts, hydroxyethyl methacrylate homopolymers and copolymers, hydroxyethyl acrylate homopolymers and copolymers, hydroxypropyl methacrylate homopolymers and copolymers, hydroxypropyl acrylate homopolymers and copolymers, hydroxybutyl methacrylate homopolymers Polymers and copolymers, homopolymers and copolymers of hydroxybutyl acrylate, polyethylene glycol , Hydroxypropylene polymers, polyvinyl alcohols, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymers and copolymers having a hydrolysis degree of 60% by mass or more, preferably 80% by mass or more Methacrylamide homopolymers and polymers, N-methylolacrylamide homopolymers and copolymers, polyvinylpyrrolidone, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, etc. Is mentioned.

  The binder polymer preferably has a weight average molecular weight of 5000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more, preferably 2000 to 250,000. More preferred. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1.1 to 10.

The binder polymer may be a random polymer, a block polymer, a graft polymer, or the like, but is preferably a random polymer.
Such a binder polymer can be synthesized by a conventionally known method. The binder polymer having a crosslinkable group in the side chain can be easily synthesized by radical polymerization or polymer reaction.

A binder polymer may be used independently or may be used in mixture of 2 or more types.
The content of the binder polymer is preferably 10 to 90% by mass and more preferably 20 to 80% by mass with respect to the total solid content of the image recording layer. Within this range, good image area strength and image formability can be obtained.
Moreover, it is preferable to use a polymeric compound and a binder polymer in the quantity used as 1 / 9-7 / 3 by mass ratio.

<Surfactant>
In the present invention, it is preferable to use a surfactant in the image recording layer in order to promote on-press developability at the start of printing and to improve the coated surface state. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants. Surfactant may be used independently and may be used in combination of 2 or more type.

  The nonionic surfactant used for this invention is not specifically limited, A conventionally well-known thing can be used. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol Fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N N- bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid ester, trialkylamine oxide, polyethylene glycol, copolymers of polyethylene glycol and polypropylene glycol.

  The anionic surfactant used in the present invention is not particularly limited, and conventionally known anionic surfactants can be used. For example, fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate esters, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy poly Oxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl esters Sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alcohol Ruphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene / maleic anhydride Examples thereof include partial saponification products of polymers, partial saponification products of olefin / maleic anhydride copolymers, and naphthalene sulfonate formalin condensates.

The cationic surfactant used in the present invention is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
The amphoteric surfactant used in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric esters, and imidazolines.

  Of the above surfactants, the term “polyoxyethylene” can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, etc. These surfactants can also be used.

  More preferable surfactants include fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Examples of such fluorosurfactants include anionic types such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl phosphates; amphoteric types such as perfluoroalkyl betaines; Cation type such as trimethylammonium salt; perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, perfluoroalkyl Nonionic types such as an oligomer containing a group, a hydrophilic group and a lipophilic group, and a urethane containing a perfluoroalkyl group and a lipophilic group. Moreover, the fluorine-type surfactant described in each gazette of Unexamined-Japanese-Patent No. 62-170950, 62-226143, and 60-168144 is also mentioned suitably.

Surfactant can be used individually or in combination of 2 or more types.
The surfactant is preferably contained in the image recording layer in an amount of 0.001 to 10% by mass, and more preferably 0.01 to 5% by mass.

<Colorant>
In the image recording layer of the present invention, a dye having a large absorption in the visible light region can be used as an image colorant. Specifically, 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 (orientated chemistry) Manufactured by Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in Japanese Patent No. 293247. In addition, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can also be suitably used.
These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The amount added is preferably 0.01 to 10% by mass in the image recording layer.

<Bakeout agent>
In the image recording layer of the present invention, a compound that is discolored by an acid or a radical can be added to produce a printout image. As such a compound, for example, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

  Specific examples include brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafuchsin, Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Kogyo Co., Ltd.], Oil Pink # 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Gaku Kogyo Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red RR [Orient Chemical Co., Ltd.], Oil Green # 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [made by Hodogaya Chemical Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p- Diethylaminophenyliminonaphthoquinone, 2-carboxystearylamino-4-pN, N-bis (hydroxyethyl) amino-phenyliminonaphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4- - dyes and p of diethylamino phenyl imino-5-pyrazolone, p ', p "- hexamethyl triamnotriphenylmethane (leuco crystal violet), and a leuco dye such as Pergascript Blue SRB (manufactured by Ciba-Geigy).

  In addition to the above, a leuco dye known as a material for thermal paper or pressure-sensitive paper is also suitable. Specific examples include crystal violet lactone, malachite green lactone, benzoylleucomethylene blue, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) amino-fluorane, 2-anilino. -3-methyl-6- (N-ethyl-p-toluidino) fluorane, 3,6-dimethoxyfluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) ) -Fluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane, 3 -(N, N-diethylamino) -6-methyl-7-xylidinofluorane, 3- (N, N-diethylamino) -6-methyl-7-chloro Fluorane, 3- (N, N-diethylamino) -6-methoxy-7-aminofluorane, 3- (N, N-diethylamino) -7- (4-chloroanilino) fluorane, 3- (N, N-diethylamino) -7-chlorofluorane, 3- (N, N-diethylamino) -7-benzylaminofluorane, 3- (N, N-diethylamino) -7,8-benzofluorane, 3- (N, N-dibutyl) Amino) -6-methyl-7-anilinofluorane, 3- (N, N-dibutylamino) -6-methyl-7-xylidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-n-butyl- -Methylindol-3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl- 2-methylindol-3-yl) -4-zaphthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, and the like.

  It is preferable to add the dye which changes color by an acid or a radical to the image recording layer at a ratio of 0.01 to 10% by mass.

<Thermal polymerization inhibitor>
In order to prevent unnecessary thermal polymerization of the polymerizable compound (C) during production or storage of the image recording layer, a small amount of a thermal polymerization inhibitor is preferably added to the image recording layer in the present invention.
Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4 ′.
Preferred examples include -thiobis (3-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), and N-nitroso-N-phenylhydroxylamine aluminum salt.
The thermal polymerization inhibitor is preferably contained in the image recording layer in an amount of about 0.01 to about 5% by mass.

<Higher fatty acid derivatives, etc.>
In the image recording layer of the present invention, a higher fatty acid derivative such as behenic acid or behenic acid amide or the like is added to prevent polymerization inhibition due to oxygen, and the surface of the image recording layer is dried during coating. It may be unevenly distributed. The amount of the higher fatty acid derivative added is preferably about 0.1 to about 10% by mass with respect to the total solid content of the image recording layer.

<Plasticizer>
The image recording layer in the invention may contain a plasticizer in order to improve the on-press developability.
Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; Glycol esters such as glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate; polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate in.
The plasticizer is preferably contained in the image recording layer at a ratio of about 30% by mass or less.

<Inorganic fine particles>
The image recording layer in the present invention may contain inorganic fine particles in order to enhance the interfacial adhesiveness by surface roughening, improve the cured film strength of the image area, and improve the on-press developability of the non-image area.
As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate, or a mixture thereof is preferably exemplified.
The inorganic fine particles preferably have an average particle size of 5 nm to 10 μm, and more preferably 0.5 μm to 3 μm. Within the above range, it is possible to form a non-image portion having excellent hydrophilicity that is stably dispersed in the image recording layer, sufficiently retains the film strength of the image recording layer, and hardly causes stains during printing.
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 20% by mass or less, and more preferably 10% by mass or less, based on the total solid content of the image recording layer.

<Low molecular hydrophilic compound>
The image recording layer in the invention may contain a hydrophilic low molecular weight compound for improving on-press developability. Examples of hydrophilic low-molecular compounds include water-soluble organic compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and the like Examples thereof include organic carboxylic acids such as salts, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid and amino acids, and salts thereof.

(Formation of image recording layer)
In the present invention, several modes can be used as a method for incorporating the above-mentioned image recording layer constituents into the image recording layer. One is a molecular dispersion type image recording layer in which the constituent components are dissolved and applied in an appropriate solvent as described in JP-A-2002-287334, for example. In another embodiment, for example, as described in JP-A Nos. 2001-277740 and 2001-277742, all or part of the components (A), (B) and (C) are contained in microcapsules. It is a microcapsule type image recording layer that is included and contained in the image recording layer. further. In the microcapsule type image recording layer, the constituent component may be contained outside the microcapsule. Here, it is preferable that the microcapsule-type image recording layer includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule. In order to obtain better on-press developability, it is advantageous that the image recording layer is a microcapsule type image recording layer.

  As a method of microencapsulating the above-mentioned image recording layer constituent components, known methods 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 precipitation of polymer, 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 the said ethylenically unsaturated bond which can introduce | transduce the 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 recording layer in the present invention is formed by preparing and applying a coating solution by dispersing or dissolving necessary constituents in a solvent using any of the above-described embodiments. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, toluene, water and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The image recording layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeating a plurality of coatings and dryings.

Image recording layer coating weight (solids) is preferably from ^{0.3~1.5g / m 2, 0.5~1.5g / m} 2 is more preferable.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

[Back coat]
A back coat can be provided on the back surface of the support, if necessary, after surface treatment or after forming an undercoat layer on the support.
Examples of the back coat include hydrolysis and polycondensation of organic polymer compounds described in JP-A-5-45885, organometallic compounds or inorganic metal compounds described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this manner is preferred. Among them, it is inexpensive to use a silicon alkoxy compound such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4. It is preferable in terms of easy availability.

[Undercoat layer]
In the lithographic printing plate precursor according to the invention, an undercoat layer can be provided between the image recording layer and the support, if necessary. Since the undercoat layer functions as a heat insulating layer, heat generated by exposure with an infrared laser is not diffused to the support and can be used efficiently, so that there is an advantage that high sensitivity can be achieved. In addition, in the unexposed area, the image recording layer is easily peeled off from the support, so that the on-press developability is improved.
As the undercoat layer, specifically, a silane coupling agent having an ethylenic double bond reactive group capable of addition polymerization described in JP-A-10-282679, an ethylenic double bond reaction Preferable examples include a phosphorus compound having a group.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 3 to 30 mg / m ^2.

[Protective layer]
In the lithographic printing plate precursor of the present invention used in the lithographic printing method of the present invention, image recording is performed as necessary to prevent the occurrence of scratches in the image recording layer, to block oxygen, and to prevent ablation during high-illuminance laser exposure. A protective layer can be provided on the layer.
In the present invention, the exposure is usually performed in the atmosphere, but the protective layer is an image of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that inhibit the image forming reaction caused by exposure in the image recording layer. This prevents the recording layer from being mixed, and prevents the image formation reaction from being hindered by exposure in the air. Therefore, the properties desired for the protective layer are low permeability of low-molecular compounds such as oxygen, furthermore, good transparency of light used for exposure, excellent adhesion to the image recording layer, and It is preferable that it can be easily removed in an on-press development process after exposure. Various studies have been made on protective layers having such characteristics, and are described in detail, for example, in US Pat. No. 3,458,311 and JP-A-55-49729.

Examples of the material used for the protective layer include water-soluble polymer compounds that are relatively excellent in crystallinity. Specific examples include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid. Among these, when polyvinyl alcohol (PVA) is used as a main component, the best results are obtained for basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol may be partially substituted with an ester, ether or acetal as long as it contains an unsubstituted vinyl alcohol unit for providing the oxygen barrier property and water solubility necessary for the protective layer, and a part of the other You may have a copolymerization component.
Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100 mol% and a polymerization degree in the range of 300 to 2400. Specifically, for example, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA- HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420, PVA-613, and L-8 are mentioned.

The components of the protective layer (selection of PVA, use of additives, etc.), coating amount, etc. are appropriately selected in consideration of fogging properties, adhesion, scratch resistance, etc. in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of PVA (that is, the higher the content of unsubstituted vinyl alcohol units in the protective layer), the higher the film thickness, the higher the oxygen barrier property, which is preferable in terms of sensitivity. . In order to prevent unnecessary polymerization reaction during production and storage, or unnecessary fogging during image exposure, image line weighting, and the like, it is preferable that the oxygen permeability is not excessively high. Accordingly, the oxygen permeability A at 25 ° C. and 1 atm is preferably 0.2 ≦ A ≦ 20 (cc / m ² · day).

  As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.

  The thickness of the protective layer is preferably 0.1 to 5 μm, particularly preferably 0.2 to 2 μm.

In addition, adhesion to the image area, scratch resistance, and the like are extremely important in handling the lithographic printing plate precursor. On the other hand, various proposals have been made to improve the adhesion between the image recording layer and the protective layer. For example, JP-A-49-70702 and British Patent Application No. 1303578 disclose an acrylic emulsion, a water-insoluble vinylpyrrolidone-vinyl acetate copolymer, etc. in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on an image recording layer. Any of these known techniques can be used in the present invention. The method for applying the protective layer is described in detail, for example, in US Pat. No. 3,458,311 and JP-A-55-49729.
Furthermore, other functions can be imparted to the protective layer. For example, by adding a colorant (for example, a water-soluble dye) that is excellent in the transparency of infrared rays used for exposure and that can efficiently absorb light of other wavelengths, it is safe light without causing a decrease in sensitivity. Suitability can be improved.

[Plate making, printing]
In the planographic printing method of the present invention, the above-described planographic printing plate precursor of the present invention is exposed imagewise with an infrared laser.
Although the infrared laser used for this invention is not specifically limited, The solid laser and semiconductor laser which radiate | emit infrared rays with a wavelength of 760-1200 nm are mentioned suitably. The output of the infrared laser is preferably 100 mW or more. In order to shorten the exposure time, it is preferable to use a multi-beam laser device.
The exposure time per pixel is preferably within 20 μsec. Moreover, it is preferable that irradiation energy amount is 10-300 mJ / cm < ² >.

In the lithographic printing method of the present invention, as described above, after exposing the lithographic printing plate precursor of the present invention imagewise with an infrared laser, an oil-based ink and an aqueous component are supplied without any development processing steps. Print.
Specifically, after exposing the lithographic printing plate precursor with an infrared laser, mounting it on a printing machine without passing through the development process, printing the lithographic printing plate precursor on the printing machine, Examples include a method of printing with an infrared laser and printing without going through a development process.

After exposing the lithographic printing plate precursor imagewise with an infrared laser and supplying it with an aqueous component and oil-based ink without passing through a development process such as a wet development process, in the exposed part of the image recording layer, The image recording layer cured by exposure forms an oil-based ink receiving portion having an oleophilic surface. On the other hand, in the unexposed portion, the uncured image recording layer is dissolved or dispersed and removed by the supplied aqueous component and / or oil-based ink, and a hydrophilic surface is exposed in that portion.
As a result, the aqueous component adheres to the exposed hydrophilic surface, and the oil-based ink is deposited on the image recording layer in the exposed area, and printing is started. Here, the water-based component or the oil-based ink may be supplied to the printing plate first, but the oil-based ink is first used to prevent the water-based component from being contaminated by the image recording layer in the unexposed area. It is preferable to supply. As the aqueous component and the oil-based ink, a dampening water for normal lithographic printing and a printing ink are used.
In this way, the lithographic printing plate precursor is subjected to on-press development on an offset printing machine and used as it is for printing a large number of sheets.
〔Example〕

Hereinafter, although an example and a comparative example explain the present invention in detail, the present invention is not limited to these.
(Example 1)
1. Production of Support for Lithographic Printing Plate Using an aluminum plate defined in JIS A1050 with a plate thickness of 0.24 mm, the following treatment was sequentially performed to produce an aluminum support.

(A) Etching treatment with alkali agent The aluminum plate was subjected to etching treatment by spraying at a caustic soda concentration of 26% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. to dissolve the aluminum plate at 6 g / m ² . Then, water washing by spraying was performed.
(B) Desmutting treatment Desmutting treatment was performed by spraying with a 1% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut was the waste liquid from the following electrochemical surface roughening process using alternating current in an aqueous nitric acid solution.

(C) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating current of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous nitric acid solution (containing 0.5% by mass aluminum ions and 0.007% by mass ammonium ions) at a temperature of 50 ° C. An electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time TP of 2 msec until the current value reaches a peak from zero, a DUTY ratio of 1: 1. Ferrite was used for the auxiliary anode.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 270 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.

(D) Etching treatment The aluminum plate is subjected to an etching treatment by spraying at a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C. to dissolve the aluminum plate by 0.2 g / m ² , The smut component mainly composed of aluminum hydroxide generated when electrochemical surface roughening was used was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Then, water washing by spraying was performed.
(E) Desmut treatment The desmut treatment is performed by spraying with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water by spraying and drying to dry the substrate 1. Obtained.

(F) Anodizing treatment An aqueous solution (containing 0.5% by mass of aluminum ions) having a sulfuric acid concentration of 170 g / L was used as the anodizing solution, a direct current voltage was used, a current density of 5 A / dm ² , a temperature of 43 ° C., 33 The aluminum plate was anodized under the conditions of seconds to form an anodized film. 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.
The amount of the anodized film was 3 g / m ² .
(G) Pore wide treatment The substrate 1 after the anodic oxidation treatment was immersed in an aqueous sodium hydroxide solution having a pH of 13 at a temperature of 50 ° C. for 30 seconds, then washed with water, dried and subjected to a pore wide treatment.

(H) Formation of inorganic compound particle layer Colloidal alumina having a particle size of 10 to 100 nm is formed on the substrate 1 after the pore-wide treatment. The coating amount after drying a water suspension containing 0.5% by mass of particles (Nissan Chemical, AS200, thermal conductivity 36 W / (m · K)) to 0.05 g / m ² using a bar coater. The mixture was applied and dried at 100 ° C. for 2 minutes using an oven to form an inorganic compound particle layer.
(I) Sealing treatment The substrate 1 after forming the inorganic compound particle layer was subjected to sealing treatment by continuously immersing it in a 10 mass% aqueous solution of No. 3 sodium silicate without leaving time. The treatment liquid temperature was 70 ° C. and the immersion treatment time was 14 seconds. Thereafter, the substrate was washed with water by spraying and dried to obtain a lithographic printing plate support having an inorganic compound layer provided on the anodized film.

(J) Formation of hydrophilic layer The following composition was uniformly mixed, and stirred at 20 ° C for 2 hours for hydrolysis to obtain a sol-like hydrophilic coating liquid composition 1.
<Hydrophilic coating liquid composition 1>
・ Specific hydrophilic polymer (1-1) 0.21 g
・ Tris (acetylacetone) aluminum 0.01g
・ Methanol 4.70g
・ Water 4.70g

Thereafter, the hydrophilic coating solution composition 1 is applied onto a lithographic printing plate support so that the coating amount after drying is 0.03 g / m ² and dried by heating at 120 ° C. for 1 minute. A hydrophilic surface was obtained.
When the contact angle (airborne water droplet) of the hydrophilic surface of the support obtained here was measured using CA-Z manufactured by Kyowa Interface Science Co., Ltd., it was 6.5 °, indicating that it has high hydrophilicity. Indicated.

(K) Design of photosensitive layer On the support coated with the hydrophilic layer, an image recording layer coating solution (1) having the following composition was bar coated, followed by oven drying at 70 ° C. for 60 seconds. An image recording layer of .8 g / m ² was formed to obtain a lithographic printing plate precursor (1).

Image recording layer coating solution (1)
・ Water 100g
・ The following microcapsule (1) (in terms of solid content) 5 g
-0.5 g of the following polymerization initiator (1)
・ 0.2 g of the following fluorosurfactant (1)

(Synthesis of microcapsule (1))
As an oil phase component, trimethylolpropane and xylene diisocyanate adduct (manufactured by Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd., SR444) 3.15 g, 0.35 g of the following infrared absorber (1), 1 g of 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane (ODB manufactured by Yamamoto Kasei), and Pionin A-41C (Takemoto Yushi Co., Ltd.) ) 0.1 g was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 3 hours. The solid content concentration of the microcapsule liquids (16) to (20) thus obtained was diluted with distilled water so as to be 20% by mass. All of the average particle diameters were 0.3 μm.

[Exposure and printing]
The obtained lithographic printing plate precursor was exposed with a Trend setter 3244VX manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 9 W, an outer drum rotating speed of 210 rpm, and a resolution of 2400 dpi. The exposure image includes a thin line chart. The exposed exposed original plate was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg without developing. Dampening water (EU-3 (etch solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (Dainippon Ink & Chemicals, Inc.) After supplying dampening water and ink, printing was performed at a printing speed of 6000 sheets per hour.
When the on-press development of the unexposed portion of the image recording layer on the printing machine was completed and the number of printing paper sheets required until ink was not transferred to the printing paper was measured as on-press developability, about 40 A printed material having no stain on the non-image area was obtained.

[Evaluation]
The lithographic printing plate (1) obtained above was evaluated for the stain resistance, neglected stain resistance, fine line reproducibility, and printing durability by the following methods.

(1) Dirt prevention property The blanket was stained visually after printing 10,000 sheets. The antifouling property was evaluated on a 10-point scale according to the degree of dirt on the blanket. Larger numbers indicate better antifouling properties. The results are shown in Table 1.

(2) Leaving stain prevention property In the above-described stain prevention property evaluation, after printing 10,000 sheets, the plate was left to stand for 1 hour, and then printing was started again to visually evaluate the stain on the blanket in the non-image area. . The ability to prevent neglected stains was evaluated in four grades, ◎, ○, Δ, and ×, starting from the one with less dirt on the blanket. The results are shown in Table 1.

(3) Fine line reproducibility After printing 500 sheets and confirming that a printed matter free from ink stains in the non-image area was obtained, a fine line chart (10, 12, 14, 16, 18, 20, 25, 30) of the printed matter was obtained. , 35, 40, 60, 80, 100 and 200 μm exposed thin lines) were observed with a magnifying glass of 25 times, and the fine line reproducibility was evaluated by the fine line width reproduced with ink without interruption. The results are shown in Table 1.

(4) Printing durability As the number of printed sheets is increased, the image recording layer is gradually worn and the ink acceptability is lowered, so that the ink density in the printing paper is lowered. The ink density (reflection density) is less than that at the start of printing.
The printing durability was evaluated based on the number of printed sheets when it decreased by one. The results are shown in Table 1.

(Example 2)
A lithographic printing plate precursor (2) was obtained in the same manner as in Example 1 except that the photosensitive layer was changed to the image recording layer coating solution (2) having the following composition.

Image recording layer coating solution (2)
・ The following infrared absorber (2) 0.05 g
・ 0.2 g of the above polymerization initiator (1)
・ The following binder polymer (1) 0.5 g
(Average molecular weight 80,000)
・ Polymerizable compound 1.0g
Isocyanuric acid EO-modified triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester M-315)
・ Victoria Pure Blue Naphthalenesulfonate 0.02g
・ 0.1 g of the above-mentioned fluorosurfactant (1)
・ Methyl ethyl ketone 18.0g

[Exposure, printing and evaluation]
Exposure, printing, and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Examples 3 to 5)
Lithographic printing plate precursors 3 to 5 were obtained in the same manner as in Example 2 except that the type of the specific hydrophilic polymer was changed as shown in Table 1 in forming the hydrophilic layer.

[Exposure, printing and evaluation]
Exposure, printing, and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
The lithographic printing plate precursor (1 ′) was prepared in the same manner as in Example 2 except that (g) pore-wide treatment, (h) the inorganic compound particle layer was not formed, and the hydrophilic layer was not formed. Obtained.

[Exposure, printing and evaluation]
Exposure, printing, and evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

  From the results shown in Table 1, it can be seen that the planographic printing plate precursor of the present invention is excellent in on-press developability, stain resistance, neglected stain resistance, fine line reproducibility, and printing durability.

It is a cross-sectional schematic diagram of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support for lithographic printing plate 2 Aluminum plate 3 Anodized film layer 4 Micropore in anodized film layer 5 Inner diameter of micropore 6 Inorganic compound particle 7 Inorganic compound layer 8 Pore of inorganic compound layer

Claims (3)

  A treatment liquid in which a layer of inorganic compound particles having a major axis larger than the pore diameter of the anodized film is provided on a support having a roughened aluminum plate and provided with an anodized film, and the inorganic compound particles can be dissolved. A hydrophilic layer in which a hydrophilic graft chain is present, (A) an infrared absorber, and (B) polymerization on a lithographic printing plate support obtained by fusing the inorganic compound particles with each other. A lithographic printing plate precursor comprising an initiator, and (C) an image recording layer containing a polymerizable compound and removable in this order by printing ink, dampening water, or both.   2. The lithographic printing plate precursor as claimed in claim 1, wherein the treatment liquid contains at least one of fluorine and silicon.   The lithographic printing plate precursor according to claim 1 or 2 is mounted on a printing press and imagewise exposed with an infrared laser, or imagewise exposed with an infrared laser and then mounted on a printing press, and the lithographic printing plate precursor A lithographic printing method for printing by supplying printing ink and fountain solution to remove the infrared unexposed portion of the image recording layer.

Images