JP2008213360A - Lithographic printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithographic printing method which enables image recording to be carried out by infrared laser to obtain a high plate wear, and stable and good press developing performance and control of press developing tails generation to be attained. <P>SOLUTION: In the process of feeding moistening water or the moistening water and printing ink from a dampening roller after exposing a lithographic printing original plate having an image recording layer which is in a film removing manner developed by feeding printing ink and/or dampening water, a water amount on a plate surface is measured, and when a specified water amount is attained, an ink roller is touched to the plate surface to obtain the lithographic printing method. A method of measuring a removing amount of the image recording layer and making the ink roller contact to the plate surface when the removal is started instead of the measurement of water content is of a preferable mode. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a planographic printing method. More specifically, the present invention relates to a lithographic printing method in which a so-called direct plate-making lithographic printing plate precursor that can be directly made by scanning an infrared laser based on a digital signal from a computer or the like is developed and printed on a printing machine.

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). As described above, a difference in ink adhesion is caused on the surface of a lithographic printing plate, and after ink is applied only to an image portion, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, 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. Usually, the lithographic printing plate precursor is exposed through an original image such as a lithographic film, and then the portion that becomes the image portion of the image recording layer is left. A lithographic printing plate is obtained by performing plate making by a method of dissolving and removing with a solvent and exposing a hydrophilic support surface to form a non-image portion.

  In the conventional plate making process of a lithographic printing plate precursor, a step of dissolving and removing an unnecessary image recording layer with a developer or the like is necessary after exposure. However, such additional wet processing is unnecessary or Simplification is cited as one of the issues. 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 simple plate making method, an image recording layer that can remove unnecessary portions of the image recording layer in a normal printing process is used. A method called on-press development has been proposed in which unnecessary portions are removed to obtain a lithographic printing plate.
As a specific method for on-press development, for example, a method using a lithographic printing plate precursor having an image recording layer that can be dissolved or dispersed in a dampening water, an ink solvent, or an emulsion of a dampening water and an ink. , Method of mechanically removing the image recording layer by contact with rollers or blankets of a printing press, cohesion of the image recording layer or adhesion between the image recording layer and the support by penetration of dampening water, ink solvent, etc. There is a method in which after the force is weakened, the image recording layer is mechanically removed by contact with rollers or a blanket.
In the present invention, unless otherwise specified, the “development process step” means using a device other than a printing press (usually an automatic developing machine) and contacting a liquid (usually an alkaline developer). Refers to the process of removing the image recording layer of the lithographic printing plate precursor as a non-image part and exposing the surface of the hydrophilic support, and “on-press development” refers to a liquid (usually normal) Indicates a method and a step of removing the image recording layer in a portion to be a non-image portion of the planographic printing plate precursor and exposing the surface of the hydrophilic support by contacting with a printing ink and / or a dampening solution.

  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 technology for electronically processing, storing, and outputting image information by a computer has become widespread, and various new image output methods corresponding to such digitization technology will be 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 and YAG lasers have become available at low cost, so these high-power lasers can be used as a method for producing lithographic printing plates by scanning exposure that can be easily incorporated into digitization technology. The method used as a means is 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. On the other hand, in the method using the above-described high-power laser, a large amount of light energy is irradiated to the exposure region in a very 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 form or a structure is caused and the change is used for image recording. Therefore, image information is input by light energy such as laser light, but image recording is performed in a state where 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.

  In recent years, the development of lasers has been remarkable, and in particular, semiconductor lasers and solid-state lasers that emit infrared light with a wavelength of 760 to 1200 nm can be easily obtained with high output and small size. Such an infrared laser is extremely useful as a recording light source for making a plate directly from digital data such as a computer.

As an on-press development type lithographic printing plate precursor for image recording with an infrared laser, for example, Patent Document 1 discloses that an image forming layer in which hydrophobic thermoplastic polymer particles are dispersed in a hydrophilic binder is hydrophilic. A lithographic printing plate precursor provided on a support is described. 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 machine 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. In addition, there is a problem that the fine particles are moistened and easily mixed in the water, and the water is easily contaminated.

On the other hand, Patent Documents 2, 3 and 4 describe lithographic printing plate precursors containing microcapsules encapsulating a polymerizable compound on a hydrophilic support as polymerized photosensitive materials that can be chemically amplified. Yes.
Patent Document 5 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.
Further, Patent Document 6 discloses a lithographic printing plate precursor in which at least a part of an unexposed portion of a radical polymerizable image recording layer is not dissolved in printing ink, fountain solution or both, and is removed film-free. Are listed.

Thus, the method using the polymerization reaction 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, and Even in the unexposed area, the image strength is further increased by the film-removal type image recording layer which is essentially insoluble in water.
In this film-removal type image recording layer, the removed film is hydrophobic and dampened without being dissolved in water, and is taken into the printing ink where it is refined and rendered harmless on the printing press. In other words, the water-soluble image recording layer that has been conventionally used to impart developability on the machine had very poor fountain solution contamination, but the film removal type image recording layer significantly improved the fountain solution contamination. Was made.

However, when using the development plate on the film removal type machine in various printing machines, the number of watering at the start of printing, the number of inking, the amount of water supply, the printing speed, and the watering roller and the plate surface Depending on the printing press settings such as the slip ratio and the nip pressure of each inking roller, the on-press development may be delayed, the amount of waste paper increases, and the blanket and impression cylinder outside the printing paper may become contaminated with ink. It was.
Further, in some cases, the stripped development residue removed from the film may be dampened and floated in water, or may be reattached on the printing plate image area, which may adversely affect the image quality of the printed matter.

Japanese Patent No. 2938397 JP 2001-277740 A JP 2001-277742 A JP 2004-106457 A JP 2002-287334 A JP 2005-335366 A

  Accordingly, the present invention provides a lithographic printing method which can record an image with an infrared laser, obtain high printing durability, and achieve stable and good on-machine developability and suppression of on-machine development residue.

  As a result of diligent research to achieve the above object, the present inventor has supplied sufficient water at the start of printing for the purpose of stable and good on-press developability and on-press development debris generation, and thereafter Immediately ascertain that it is effective to bring the inking roller into contact with the plate surface. When the moisture on the plate surface reaches a certain amount, or when the image recording layer in the unexposed area begins to be developed with water, The inventors found that it is most effective to contact the roller and completed the present invention. That is, the present invention is as follows.

1. A lithographic printing method having the following steps (i) to (iv), wherein the amount of water on the lithographic printing plate precursor is measured in step (ii), and when the specified amount of water is reached (iii) A lithographic printing method comprising performing a step.
(I) A lithographic printing plate precursor having an image recording layer developed film-developing by supplying printing ink and / or dampening water on a support is mounted on a plate cylinder of a printing machine, Or after imagewise exposure and mounting on a plate cylinder of a printing press;
(Ii) supplying dampening water or dampening water and printing ink from a watering roller to the lithographic printing plate precursor after exposure;
(Iii) Next, supplying printing ink from an ink roller to the lithographic printing plate precursor to remove unexposed portions;
(Iv) A printing step.

  2. 2. The lithographic printing method as described in 1 above, wherein the specified water content is a water content that maximizes the water content measured in the step (ii).

3. A lithographic printing method having the following steps (i) to (iv), wherein the removal amount of the image recording layer of the lithographic printing plate precursor is measured in the step (ii) and the removal starts (iii) A lithographic printing method comprising the steps of:
(I) A lithographic printing plate precursor having an image recording layer developed film-developing by supplying printing ink and / or dampening water on a support is mounted on a plate cylinder of a printing machine, Or after imagewise exposure and mounting on a plate cylinder of a printing press;
(Ii) supplying dampening water or dampening water and printing ink from a watering roller to the lithographic printing plate precursor after exposure;
(Iii) Next, supplying printing ink from an ink roller to the lithographic printing plate precursor to remove unexposed portions;
(Iv) A printing step.

4). 4. The lithographic printing method as described in 1 or 3 above, wherein the image recording layer contains (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound.
5. 5. The lithographic printing method as described in 4 above, wherein the image recording layer further contains (D) a binder polymer that does not dissolve in the fountain solution.
6). 6. The lithographic printing method according to any one of 1 to 5, wherein the moisture content on the original plate is measured using a plate reflection infrared measuring device.

  According to the present invention, it is possible to provide a lithographic printing method in which image recording is performed with an infrared laser, high printing durability is obtained, and stable and good on-machine developability and on-machine development residue generation suppression can be achieved.

Hereinafter, the present invention will be described in detail.
[Lithographic printing plate precursor]
(Image recording layer)
The lithographic printing plate precursor used in the lithographic printing method of the present invention has an image recording layer which is developed film-developing by supplying printing ink and / or dampening water on a support. The recording layer preferably contains (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound, and can be recorded by irradiation with infrared rays. The image recording layer preferably contains (D) a binder polymer that does not dissolve in the fountain solution since it is developed in a film-removing manner.
In this lithographic printing plate precursor, the exposed portion of the image recording layer is cured to form a hydrophobic (lipophilic) region, and the unexposed portion is dampened with water, ink or dampening water and ink at the start of printing. The emulsion is quickly removed from the support by the emulsion, but is removed film-like.

<Definition of film removal>
In the present invention, “removable removal” means a phenomenon in which part of the image recording layer is peeled off as a film, unlike the phenomenon in which development proceeds due to dissolution of the image recording layer. The case where the horizontal size (direction perpendicular to the film thickness direction) of the formed image recording layer component is equal to or larger than the film thickness of the image recording layer is defined as film removal.
As long as the above conditions are satisfied, the horizontal size is not particularly limited. However, if the film is removed, the on-machine development becomes faster as the starting point increases. The size of the recording layer component is preferably small. The thickness is preferably not less than 5 mm, more preferably not less than 1 mm, and still more preferably not less than 100 μm.
Further, it is preferable that the ratio of the development removal component of the image recording layer to be removed by film removal is large because the effect of the present invention is increased. Preferably it is 20% or more, More preferably, it is 50% or more, More preferably, it is 80% or more.

<Conditions for demembrane removal>
In order to develop film-like removal, at least a part of the image recording layer does not dissolve in the printing ink and / or fountain solution within the time required for on-press development, and It is essential that the adhesive strength with the support is smaller than the adhesive strength between the surface of any of the ink form roller, water roller, blanket roller, etc. of the printing press and the outermost surface of the photosensitive material (image recording layer). is there.
Therefore, (1) an image recording layer binder that does not dissolve in printing ink and / or fountain solution within the time required for on-press development, and (2) an image recording layer in an unexposed area in the presence of fountain solution It is more preferable that the adhesion with the support is reduced, and (3) the unexposed portion is removed using the tack of the ink on the ink form roller.

<Method for observing development behavior>
It is possible to observe and evaluate the behavior during on-press development, that is, whether film removal is occurring or dissolved, by the following method.
That is, for example, “New Champion F-Gloss Medium” manufactured by Dainippon Ink & Chemicals, Inc. and dampening water are supplied onto the printing plate precursor after exposure as a transparent ink, and the on-machine development is performed. The developed removal transferred onto the sample is sampled together with the ink, and an optical microscope or SEM is used to observe whether there is a solid removal included in the definition of film removal described above. If there is a removed product, measure its size.

Next, each component of the image recording layer that can be used in the lithographic printing plate precursor according to the invention will be described.
<(A) Infrared absorber>
When forming an image of the lithographic printing plate precursor according to the present invention with a laser that emits infrared rays of 760 to 1200 nm using a light source, it is usually essential to use an infrared absorber. The infrared absorber has a function of converting the absorbed infrared ray into heat and a function of being excited by the infrared ray and transferring electrons / energy to a polymerization initiator (radical generator) described later. The 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, JP-A-58-194595, etc., 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, etc., squarylium dyes described in JP-A-58-112792, etc. And cyanine dyes described in British Patent 434,875.

Further, near infrared absorption sensitizers described in US Pat. No. 5,156,938 are also preferably used, and substituted arylbenzo (thio) described in US Pat. No. 3,881,924. ) Pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59- 41363, 59-84248, 59-84249, 59-146063, 59-146061, and pyrine compounds described in JP-A-59-216146, cyanine dyes described in JP-A-59-216146, Disclosure in the pentamethine thiopyrylium salt and the like described in US Pat. 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).
Other preferable examples of the infrared absorber of the present invention include specific indolenine cyanine dyes described in JP-A-2002-278057 as exemplified below.

  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. Ph is a phenyl group. Here, X ² represents an oxygen atom, a nitrogen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and 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.

R ¹ and R ² each independently represents 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, particularly preferably a perchlorate ion, a hexagonal salt, in view of the storage stability of the recording layer coating solution. Fluorophosphate ions and aryl sulfonate ions.

Specific examples of the cyanine dye 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. be able to.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057 described above.

  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 Application 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 for 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).

  These infrared absorbers may be added to the same layer as the other components, or may be added to another layer provided, but when a negative planographic printing plate precursor is prepared, image recording is performed. The layer is added so that the absorbance at the maximum absorption wavelength in the wavelength range of 760 nm to 1200 nm is in the range of 0.3 to 1.2 by the reflection measurement method. Preferably, it is the range of 0.4-1.1. Within this range, a uniform polymerization reaction proceeds in the depth direction of the image recording layer, and good film strength of the image area and adhesion to the support can be obtained.

  The absorbance of the image recording layer can be adjusted by the amount of infrared absorber added to the image recording layer and the thickness of the image recording layer. Absorbance can be measured by a conventional method. As a measuring method, for example, on a reflective support such as aluminum, an image recording layer having a thickness appropriately determined in a range in which the coating amount after drying is necessary as a lithographic printing plate is formed, and the reflection density is set to the optical density. And a method of measuring with a spectrophotometer by a reflection method using an integrating sphere.

<(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 the polymerization of a compound having a polymerizable unsaturated group by generating a radical 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 halides, carbonyl compounds, organic peroxides, azo polymerization initiators, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boric acid compounds, disulfone compounds, and oxime esters. Compounds and onium salt compounds.

  Specific examples of the organic halide 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 48-36281, JP 55-32070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62-58241, JP 62 -212401, JP-A-63-70243, JP-A-63-298339, M.S. P. Examples thereof include compounds described in Hutt “Journal of Heterocyclic Chemistry” 1 (No 3), (1970) and the like. Of these, oxazole compounds substituted with a trihalomethyl group and S-triazine compounds are preferred.

  More preferred are s-triazine derivatives in which at least one mono, di, or trihalogen-substituted methyl group is bonded to the s-triazine ring, and oxadiazole derivatives in which the oxadiazole ring is bonded. 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, 2- (3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4,6- Su (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-phenylthio-4,6-bis (trichloromethyl) -s-triazine, 2-benzylthio-4,6-bis (trichloromethyl) -s-tria 2,4,6-tris (dibromomethyl) -s-triazine, 2,4,6-tris (tribromomethyl) -s-triazine, 2-methyl-4,6-bis (tribromomethyl)- Examples thereof include s-triazine, 2-methoxy-4,6-bis (tribromomethyl) -s-triazine and the following compounds.

  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 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, 2, -Oxanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate , 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 ′, 4,4 ′ − Tra- (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyl And di (t-hexylperoxydihydrogen diphthalate).

  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 JP-B-6-29285, U.S. Pat. Nos. 3,479,185, 4,311,783, and 4,622,286. And, 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, 2,2 ′ -Bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (m-methoxyphenyl) biidazole, 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 Japanese Patent Publication No. 9-188710, organoboron phosphonium complexes disclosed in JP-A-9-188710, JP-A-6-348011, JP-A-7-128785, JP-A-7-140589, JP Specific examples include organoboron transition metal coordination complexes such as 7-306527 and JP-A-7-292014.

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

  Examples of the oxime ester compound include JCS Perkin II (1979) 1653-1660), JCSPerkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, and JP-A 2000-66385. Examples thereof include compounds described in JP-A No. 2000-80068, specifically the following compounds.

  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 salt suitably used in the present invention is an onium salt 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 an alkyl group having 1 to 12 carbon atoms and a carbon number. 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 represent 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. An alkyl group, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, a halogen atom An alkylamino group having 1 to 12 carbon atoms, a dialkylamino group having 1 to 12 carbon atoms, an alkylamide group or arylamide group having 1 to 12 carbon atoms, a carbonyl group, a carboxyl group, a cyano group, a sulfonyl group, and 1 carbon atom -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 preferred.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ each independently represents an aryl group having 20 or less carbon atoms, an alkyl group, an alkenyl group or an alkynyl group which may have 1 to 6 substituents. In view of reactivity and stability, an aryl group is desirable. Preferred substituents are 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, Aryloxy group having 1 to 12 carbon atoms, halogen atom, alkylamino group having 1 to 12 carbon atoms, dialkylamino group having 1 to 12 carbon atoms, alkylamide group or arylamide group having 1 to 12 carbon atoms, 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 ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, and carboxylate ions are preferable. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.

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

  The polymerization initiator is not limited to the above, but a triazine-based initiator, an organic halogen compound, an oxime ester compound, a diazonium salt, an iodonium salt, and a sulfonium salt are more preferable from the viewpoints of reactivity and stability.

  These polymerization initiators are each preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and still more preferably 0.8 to 20% by mass with respect to the total solid content constituting the image recording layer. Can be added at a ratio of 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 that can be used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is a compound having at least one terminal ethylenically unsaturated bond, preferably two or more. To be elected. 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.), 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 a monofunctional or polyfunctional A dehydration-condensation reaction product with 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 Also suitable are substitution reaction products of unsaturated carboxylic acid esters or amides having a leaving substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines or thiols. 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, polyester acrylate oligomer, isocyanuric acid There are EO-modified triacrylate 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 Sorbitol tetritaconate, etc. 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, for example, aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, and JP-A-59-5241. Those having an aromatic skeleton described in 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.

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinyl urethane 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. Compounds and the like.

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

  Further, 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-56-17654 Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable. Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, JP-A-1-105238 Can obtain a photopolymerizable composition having an excellent photosensitive speed.

  Other examples include reacting polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. And polyfunctional acrylates and methacrylates such as epoxy acrylates. Further, 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. be able to. 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, etc. 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 area, that is, the cured film, those having three or more functionalities are preferable, and furthermore, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrenic compound, vinyl ether type). A method of adjusting both sensitivity and strength by using a compound) is also effective.
Further, the selection / use method of the addition polymerization compound is also an important factor for the compatibility and dispersibility with other components (for example, binder polymer, initiator, colorant, etc.) in the image recording layer. In some cases, the compatibility can be improved by using a low-purity compound or by using two or more kinds in combination. In addition, a specific structure may be selected for the purpose of improving the adhesion of the substrate and the protective layer described later.
The polymerizable compound is preferably used in the range of 5 to 80% by mass, more preferably 25 to 75% by mass with respect to the nonvolatile component in the image recording layer. These may be used alone or in combination of two or more.
In addition, the use method of the above-mentioned polymerizable compound can arbitrarily select an appropriate structure, blending, and addition amount from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface adhesiveness, etc. Depending on the case, a layer configuration and coating method such as undercoating and overcoating can be performed.

<(D) Binder polymer>
The binder polymer that can be used in the present invention must not be dissolved in the fountain solution as described above.
As long as this requirement is satisfied, a conventionally known one can be used without limitation, and a linear organic polymer having a film property is preferable. Examples of such a binder polymer include acrylic resin, polyvinyl acetal resin, polyurethane resin, polyamide resin, epoxy resin, methacrylic resin, polystyrene resin, and novolac type phenol resin.

The binder polymer may have 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.
Examples of the polymer having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-butadiene, poly-1,4-isoprene, natural rubber, and synthetic rubber.

Examples of polymers having an ethylenically unsaturated bond in the side chain of the molecule are polymers of esters or amides of acrylic acid or methacrylic acid where the ester or amide residue (R of -COOR or -CONHR) is Mention may be made of polymers having an ethylenically unsaturated bond.
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, an alkyl group having 1 to 20 carbon atoms, an aryl group, Represents an alkoxy group or an aryloxy group, and R ¹ and R ² or R ³ may combine with each other to form a ring, n represents an integer of 1 to 10. X represents dicyclopentadienyl. Represents a residue).
Specific examples of the ester _{residue, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - 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 -NHCOO-CH 2 CH = CH 2 and - CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
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. Is mentioned.

In the case of a binder polymer having crosslinkability, for example, free radicals (polymerization initiation radicals or growth radicals in the polymerization process of a polymerizable compound) are added to the crosslinkable functional group, and a polymerization chain of a polymerizable compound is formed directly between 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 to each other so that crosslinking between the polymer molecules occurs. 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.

  (D) The binder polymer preferably has a mass average molecular weight of 5,000 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 preferably. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.

  (D) The binder polymer may be any of a random polymer, a block polymer, a graft polymer and the like, but is preferably a random polymer or a graft polymer. (D) The binder polymer can be synthesized by a conventionally known method. Examples of the solvent used in the synthesis include tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy. Examples include 2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, and water. These may be used alone or in combination of two or more. (D) As a radical polymerization initiator used when a binder polymer is synthesized, known compounds such as an azo initiator and a peroxide initiator can be used.

(D) A binder polymer may be used independently or may be used in mixture of 2 or more types.
(D) Content of binder polymer is 10-90 mass% with respect to the total solid of an image recording layer, It is preferable that it is 20-80 mass%, and it is more 30-70 mass%. preferable. Within this range, good image area strength and image formability can be obtained.
Moreover, it is preferable to use (C) polymeric compound and (D) binder polymer in the quantity used as 1 / 9-7 / 3 by mass ratio.

<Microcapsules and microgels>
In the present invention, several modes can be used as a method for incorporating the image recording layer constituent components (A) to (D) and other constituent components described later 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, for example, JP-A-2002-287334. In another embodiment, for example, as described in JP-A-2001-277740 and JP-A-2001-277742, all or part of the constituent components are encapsulated in microcapsules and contained in the image recording layer. It is a microcapsule type image recording layer. Further, in the microcapsule type image recording layer, the constituent component can 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. As another embodiment, an embodiment in which the image recording layer contains crosslinked resin particles, that is, microgel, can be mentioned. The microgel can contain a part of the constituent components (A) to (D) in and / or on the surface thereof. In particular, an embodiment in which (C) a reactive microgel is formed by having a polymerizable compound on the surface thereof is particularly preferable from the viewpoint of image forming sensitivity and printing durability.
In order to obtain better on-press developability, the image recording layer is preferably a microcapsule type or microgel type image recording layer.

As a method for microencapsulating or microgelling the 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 polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcino A method using a wall forming material, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, as shown in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method using 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 and 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 a microcapsule wall the compound which has crosslinkable functional groups, such as said (D) binder polymer introduction | transduction, such as an ethylenically unsaturated bond.

On the other hand, as a method for preparing a microgel, granulation by interfacial polymerization described in JP-B-38-19574 and JP-A-42-446, as described in JP-A-5-61214, etc. Granulation by non-aqueous dispersion polymerization can be used. However, it is not limited to these methods.
As the method using the interfacial polymerization, the known microcapsule production method described above can be applied.

  Preferred microgels used in the present invention are those granulated by interfacial polymerization and having three-dimensional crosslinking. From such a viewpoint, the material to be used is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and polyurea and polyurethane are particularly preferable.

  The average particle size of the microcapsules or microgel 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.

<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 acid 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 content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 5% by mass with respect to the total solid content of the image recording layer.

<Colorant>
In the present invention, various compounds other than these may be added as necessary. For example, 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) 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 dyes described in No. 293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can 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 relative to the total solid content of the image recording material.

<Bakeout agent>
In the image recording layer of the present invention, a compound that changes color 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-benzoflorane, 3- (N, N-dibutylamino) ) -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.

  The preferred amount of the dye that changes color by acid or radical is preferably 0.01 to 10% by mass relative to the solid content of the image recording layer.

<Polymerization inhibitor>
A small amount of a thermal polymerization inhibitor is preferably added to the image recording layer of the present invention in order to prevent unnecessary thermal polymerization of the polymerizable compound (C) during the production or storage of the image recording layer.
Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t- (Butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt are preferred.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the image recording layer.

<Higher fatty acid derivatives, etc.>
In order to prevent polymerization inhibition by oxygen, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to the image recording layer of the present invention, and the surface of the image recording layer is dried during the coating process. 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 of the present 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 content is preferably about 30% by mass or less based on the total solid content of the image recording layer.

<Inorganic fine particles>
The image recording layer of the present invention may contain inorganic fine particles for the purpose of improving the strength of the cured film in the image area and improving 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. Even if they are not photothermally convertible, they can be used for strengthening the film, enhancing interfacial adhesion by surface roughening, and the like.
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, which 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.

<Hydrophilic low molecular weight compound>
The image recording layer of the present invention may contain a hydrophilic low molecular weight compound for improving on-press developability. Examples of hydrophilic low molecular weight compounds include water-soluble organic compounds such as glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, 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 thereof, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid and amino acids, and salts thereof.

<Formation of image recording layer>
The image recording layer of the present invention is applied by preparing a coating solution by dispersing or dissolving the necessary components described above in a solvent. 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 , Dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, etc. However, it 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 also 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 repeatedly applying and drying a plurality of times.

Further, the coating amount (solid content) of the image recording layer on the support obtained after coating and drying varies depending on the use, but generally 0.3 to 3.0 g / m ² is preferable. Within this range, good sensitivity and good film properties of the image recording layer can be obtained.
Various methods can be used as the coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

(Support)
The support used for the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. Preferable supports include a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

  The thickness of the support is preferably 0.1 to 0.6 mm, more preferably 0.15 to 0.4 mm, and still more preferably 0.2 to 0.3 mm.

  Prior to using the aluminum plate, it is preferable to perform a surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it is easy to improve hydrophilicity and secure adhesion between the image recording layer and the support. Prior to roughening the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (electrochemical surface roughening treatment that dissolves the surface), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The conditions for anodizing treatment vary depending on the electrolyte used and cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is. If necessary, it contains micropore enlargement treatment, micropore sealing treatment, and hydrophilic compound described in JP-A Nos. 2001-253181 and 2001-322365. A surface hydrophilization treatment immersed in an aqueous solution can be appropriately selected and performed. Of course, the enlargement process and the sealing process are not limited to those described above, and any conventionally known method can be performed.
For example, as the sealing treatment, in addition to the vapor sealing, a single treatment with fluorinated zirconic acid, a treatment with sodium fluoride, or a vapor sealing with addition of lithium chloride is possible.

<Sealing treatment>
The sealing treatment used in the present invention is not particularly limited, and a conventionally known method can be used. Among them, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and hot water. Sealing treatment is preferred. Each will be described below.

As the inorganic fluorine compound used for the sealing treatment with an aqueous solution containing an inorganic fluorine compound, a metal fluoride is preferably exemplified.
Specifically, for example, sodium fluoride, potassium fluoride, calcium fluoride, magnesium fluoride, sodium fluoride zirconate, potassium fluoride zirconate, sodium fluoride titanate, potassium fluoride titanate, zircon fluoride Ammonium acid, ammonium fluoride titanate, potassium fluoride titanate, fluorinated zirconate, fluorinated titanate, hexafluorosilicic acid, nickel fluoride, iron fluoride, phosphor fluoride, ammonium fluoride phosphate It is done. Of these, sodium fluorinated zirconate, sodium fluorinated titanate, fluorinated zirconic acid, and fluorinated titanic acid are preferable.

  The concentration of the inorganic fluorine compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, from the viewpoint of sufficiently sealing the micropores of the anodized film. Further, in terms of stain resistance, it is preferably 1% by mass or less, and more preferably 0.5% by mass or less.

  It is preferable that the aqueous solution containing the inorganic fluorine compound further contains a phosphate compound. When the phosphate compound is contained, the hydrophilicity of the surface of the anodized film is improved, so that on-machine developability and stain resistance can be improved.

Suitable examples of the phosphate compound include phosphates of metals such as alkali metals and alkaline earth metals.
Specifically, for example, zinc phosphate, aluminum phosphate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, monoammonium phosphate, monopotassium phosphate, monosodium phosphate, dihydrogen phosphate Potassium, dipotassium hydrogen phosphate, calcium phosphate, sodium ammonium hydrogen phosphate, magnesium hydrogen phosphate, magnesium phosphate, ferrous phosphate, ferric phosphate, sodium dihydrogen phosphate, sodium phosphate, hydrogen phosphate Disodium, lead phosphate, diammonium phosphate, calcium dihydrogen phosphate, lithium phosphate, phosphotungstic acid, ammonium phosphotungstate, sodium phosphotungstate, ammonium phosphomolybdate, sodium phosphomolybdate, sodium phosphite , Tripolyphosphate Potassium, and sodium pyrophosphate. Of these, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are preferable.
The combination of the inorganic fluorine compound and the phosphate compound is not particularly limited, but the aqueous solution contains at least sodium zirconate fluoride as the inorganic fluorine compound and contains at least sodium dihydrogen phosphate as the phosphate compound. Is preferred.

  The concentration of the phosphate compound in the aqueous solution is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of improving on-press developability and stain resistance. Further, in terms of solubility, it is preferably 20% by mass or less, and more preferably 5% by mass or less.

The ratio of each compound in the aqueous solution is not particularly limited, but the mass ratio of the inorganic fluorine compound and the phosphate compound is preferably 1/200 to 10/1, and preferably 1/30 to 2/1. Is more preferable.
Further, the temperature of the aqueous solution is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, preferably 100 ° C. or lower, more preferably 80 ° C. or lower.
Further, the aqueous solution preferably has a pH of 1 or more, more preferably has a pH of 2 or more, preferably has a pH of 11 or less, and more preferably has a pH of 5 or less.
The method for sealing with an aqueous solution containing an inorganic fluorine compound is not particularly limited, and examples thereof include a production 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 the treatment is performed using the dipping method, the treatment time is preferably 1 second or longer, more preferably 3 seconds or longer, more preferably 100 seconds or shorter, and 20 seconds or shorter. More preferred.

Examples of the sealing treatment with water vapor include a method in which pressurized or normal-pressure water vapor is brought into contact with the anodized film continuously or discontinuously.
The temperature of the water vapor is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 105 ° C. or lower.
The water vapor pressure is preferably in a range (1.008 × 10 5 to 1.043 × 10 5 Pa) from (atmospheric pressure−50 mmAq) to (atmospheric pressure + 300 mmAq).
Further, the time for which the water vapor is contacted is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, more preferably 20 seconds or shorter.

Examples of the sealing treatment with hot water include a method of immersing an aluminum plate on which an anodized film is formed in hot water.
The hot water may contain an inorganic salt (for example, phosphate) or an organic salt.
The temperature of the hot water is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, and preferably 100 ° C. or lower.
Further, the time of immersion in hot water is preferably 1 second or longer, more preferably 3 seconds or longer, 100 seconds or shorter, more preferably 20 seconds or shorter.

<Hydrophilic treatment>
The hydrophilization treatment is described in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. There are such alkali metal silicate methods. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, And a method of treating with polyvinylphosphonic acid as described in each specification of No.272.

  When using a support with insufficient surface hydrophilicity such as a polyester film as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony, and a transition metal described in JP-A-2001-199175 A hydrophilic layer formed by coating a coating solution containing a colloid of oxide or hydroxide, or organic hydrophilicity obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A-2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or a metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred. Arbitrariness. Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or a hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion to the image recording layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 as the reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.

(Back coat layer)
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885, an organometallic compound or an inorganic metal compound described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this way is preferred. Of these, the use of silicon alkoxy compounds such as Si (OCH ₃ ) 4, Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ is inexpensive. It is preferable in that it is easily available.

(Undercoat layer)
In the lithographic printing plate precursor according to the invention, particularly in the case of an on-press development type lithographic printing plate precursor, an undercoat layer can be provided between the image recording layer and the support, if necessary. Since the undercoat layer easily peels off the image recording layer from the support in the unexposed area, the on-press developability is improved. In addition, in the case of infrared laser exposure, the undercoat layer functions as a heat insulating layer, so that heat generated by exposure does not diffuse to the support and can be used efficiently, so that high sensitivity can be achieved. There are advantages.
As the undercoat layer, specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, JP-A-2-304441. Preferred examples include phosphorus compounds having an ethylenic double bond reactive group described in the publication.
The most preferable undercoat layer includes a polymer resin obtained by copolymerization of a monomer having an adsorbing group / a monomer having a hydrophilic group / a monomer having a crosslinkable group.

An essential component of the polymer undercoat is an adsorptive group on the surface of the hydrophilic support. The presence or absence of adsorptivity on the surface of the hydrophilic support can be determined, for example, by the following method.
A coating night is prepared by dissolving the test compound in a readily soluble solvent, and the coating night is coated and dried on the support so that the coating amount after drying is 30 mg / m ² . Next, the support on which the test compound is applied is sufficiently washed with an easily soluble solvent, and then the residual amount of the test compound that has not been removed by washing is measured to calculate the amount of adsorption of the support. Here, the measurement of the remaining amount may be performed by directly quantifying the amount of the remaining compound or by quantifying the amount of the test compound dissolved in the cleaning liquid. The compound can be quantified by, for example, fluorescent X-ray measurement, reflection spectral absorbance measurement, liquid chromatography measurement and the like. The compound having support adsorptivity is a compound that remains at 1 mg / m ² or more even after the above-described washing treatment.

The adsorptive group on the surface of the hydrophilic support is a substance (for example, metal, metal oxide) or a functional group (for example, hydroxyl group) existing on the surface of the hydrophilic support and a chemical bond (for example, ionic bond, hydrogen bond). , Coordination bond, bond due to intermolecular force). The adsorptive group is preferably an acid group or a cationic group.
The acid group preferably has an acid dissociation constant (pKa) of 7 or less. Examples of acid groups are phenolic hydroxyl groups, carboxyl groups, —SO ₃ H, —OSO ₃ H, —PO ₃ H ₂ , —OPO ₃ H ₂ , —CONHSO ₂ —, —SO ₂ NHSO ₂ — and —COCH _2. Contains COCH ₃ . Among them -OPO ₃ H ₂ and -PO ₃ H ₂ are particularly preferred. These acid groups may be metal salts.
The cationic group is preferably an onium group. Examples of the onium group include an ammonium group, a phosphonium group, an arsonium group, a stibonium group, an oxonium group, a sulfonium group, a selenonium group, a stannonium group, and an iodonium group. An ammonium group, a phosphonium group and a sulfonium group are preferred, an ammonium group and a phosphonium group are more preferred, and an ammonium group is most preferred.

  Particularly preferred examples of the monomer having an adsorptive group include compounds represented by the following formula (I) or (II).

In the formula (I), R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms. R ¹ , R ² and R ³ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. More preferred is a hydrogen atom or a methyl group. R ² and R ³ are particularly preferably a hydrogen atom.
In the formula (I), X is an oxygen atom (—O—) or imino (—NH—). X is more preferably an oxygen atom. In the formula (I), L is a divalent linking group. L is a divalent aliphatic group (alkylene group, substituted alkylene group, alkenylene group, substituted alkenylene group, alkynylene group, substituted alkynylene group), divalent aromatic group (arylene group, substituted arylene group) or divalent A heterocyclic group, or an oxygen atom (—O—), a sulfur atom (—S—), an imino (—NH—), a substituted imino (—NR—, R is an aliphatic group, an aromatic group; Or a combination with a heterocyclic group) or carbonyl (—CO—).
The aliphatic group may have a cyclic structure or a branched structure. The number of carbon atoms in the aliphatic group is preferably 1 to 20, more preferably 1 to 15, and most preferably 1 to 10. The aliphatic group is preferably a saturated aliphatic group rather than an unsaturated aliphatic group. The aliphatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aromatic group, and a heterocyclic group.
The number of carbon atoms in the aromatic group is preferably 6 to 20, more preferably 6 to 15, and most preferably 6 to 10. The aromatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aliphatic group, an aromatic group, and a heterocyclic group.
The heterocyclic group preferably has a 5-membered or 6-membered ring as the heterocycle. The heterocycle may be condensed with another heterocycle, aliphatic ring or aromatic ring. The heterocyclic group may have a substituent. Examples of substituents include halogen atoms, hydroxyl groups, oxo groups (═O), thioxo groups (═S), imino groups (═NH), substituted imino groups (═N—R, R is an aliphatic group, aromatic Group or heterocyclic group), aliphatic group, aromatic group and heterocyclic group.
L is preferably a divalent linking group containing a plurality of polyoxyalkylene structures. The polyoxyalkylene structure is more preferably a polyoxyethylene structure. In other words, L preferably contains — (OCH ₂ CH ₂ ) _n — (n is an integer of 2 or more).
In the formula (I), Z is a functional group that adsorbs to the surface of the hydrophilic support. Y is a carbon atom or a nitrogen atom. When Y is a nitrogen atom and L is connected to Y to form a quaternary pyridinium group, Z is not essential because it exhibits adsorptivity itself.
In the formula (II), R ¹ , L and Z are as defined in the formula (I).

  Examples of typical monomers represented by formula (I) or (II) are shown below.

  Examples of the hydrophilic group of the undercoat polymer resin that can be used in the present invention include a hydroxy group, a carboxyl group, a carboxylate group, a hydroxyethyl group, a polyoxyethyl group, a hydroxypropyl group, a polyoxypropyl group, and an amino group. Preferred examples include a group, an aminoethyl group, an aminopropyl group, an ammonium group, an amide group, a carboxymethyl group, a sulfonic acid group, and a phosphoric acid group. Among these, a monomer having a sulfonic acid group exhibiting high hydrophilicity is preferable. Specific examples of the monomer having a sulfonic acid group include methallyloxybenzenesulfonic acid, allyloxybenzenesulfonic acid, allylsulfonic acid, vinylsulfonic acid, allylsulfonic acid, p-styrenesulfonic acid, methallylsulfonic acid, acrylamide- Examples thereof include t-butylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, (3-acryloyloxypropyl) butylsulfonic acid sodium salt and amine salt. Among them, 2-acrylamido-2-methylpropanesulfonic acid sodium salt is preferable from the viewpoint of hydrophilic performance and synthetic handling.

  The water-soluble polymer resin for the undercoat layer of the present invention preferably has a crosslinkable group. The crosslinkable group can improve the adhesion with the image area. In order to impart crosslinkability to the polymer resin for the undercoat layer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the side chain of the polymer, or paired with the polar substituent of the polymer resin. It can be introduced by forming a salt structure with a compound having a charged substituent and an ethylenically unsaturated bond.

  Examples of polymers having an ethylenically unsaturated bond in the side chain of the molecule are polymers of esters or amides of acrylic acid or methacrylic acid where the ester or amide residue (R of -COOR or -CONHR) is Mention may be made of polymers having an ethylenically unsaturated bond.

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, an alkyl group having 1 to 20 carbon atoms, or an aryl group. Represents an alkoxy group or an aryloxy group, and R ₁ and R ₂ or R ₃ may combine with each other to form a ring, n represents an integer of 1 to 10. X represents dicyclopentadi An enyl residue).
Specific examples of the ester _{residue, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - 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 NHCOO-CH 2 CH = CH 2, and - CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
Specific examples of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ O—Y (wherein Y represents a cyclohexene residue), —CH ₂ CH ₂ OCO—CH═CH _2. Is mentioned.
As the monomer having a crosslinkable group of the polymer resin for undercoat layer, acrylic acid or methacrylic acid ester or amide having the above crosslinkable group is suitable.

  The content of the crosslinkable group in the polymer resin for the undercoat layer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol per 1 g of the polymer resin. More preferably, it is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol. Within this range, both good sensitivity and dirtiness and good storage stability can be obtained.

The polymer resin for the undercoat layer preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1000 or more is preferable. More preferably, it is 250,000. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The polymer resin for the undercoat layer may be any of a random polymer, a block polymer, a graft polymer, etc., but is preferably a random polymer.

  As the undercoat polymer resin of the present invention, a known resin having a hydrophilic group can also be used. Specific examples of such resins include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and Salts thereof, polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, hydroxybutyl Homopolymers and copolymers of methacrylates, homopolymers of hydroxybutyl acrylate Copolymers, polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymers having a hydrolysis degree of 60 mol% or more, preferably 80 mol% or more. Polymers and copolymers, homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, polyvinylpyrrolidone, alcohol-soluble nylon, 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin A polyether etc. are mentioned.

The undercoat polymer resin may be used alone or in combination of two or more.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 30 mg / m ^2.

(Protective layer)
The lithographic printing plate precursor of the present invention is protected on the image recording layer as necessary to impart oxygen barrier properties, prevent scratches in the image recording layer, and prevent ablation that occurs during high-illuminance laser exposure. A layer (overcoat layer) can be provided.
Usually, the exposure processing of a lithographic printing plate is performed in the atmosphere. The image forming reaction in the image recording layer caused by the exposure process can be inhibited by low molecular compounds such as oxygen and basic substances present in the atmosphere. The protective layer prevents low molecular compounds such as oxygen and basic substances from entering the image recording layer, and as a result, suppresses image formation inhibition reaction in the air. Therefore, the property desired for the protective layer is to reduce the permeability of low-molecular compounds such as oxygen, and furthermore, the transparency of light used for exposure is good and the adhesiveness with the image recording layer is excellent. And it can be easily removed in an on-press development process after exposure. The protective layer having such characteristics is described in, for example, US Pat. No. 3,458,311 and JP-B-55-49729.

As a material used for the protective layer, either a water-soluble polymer or a water-insoluble polymer can be appropriately selected and used. Specifically, for example, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl imidazole, polyacrylic acid, polyacrylamide, partially saponified product of polyvinyl acetate, ethylene-vinyl alcohol copolymer, water-soluble cellulose derivative, gelatin, starch Examples thereof include water-soluble polymers such as derivatives and gum arabic, and polymers such as polyvinylidene chloride, poly (meth) acrylonitrile, polysulfone, polyvinyl chloride, polyethylene, polycarbonate, polystyrene, polyamide, and cellophane. These may be used in combination of two or more as required.
Examples of relatively useful materials among the above materials include water-soluble polymer compounds having excellent crystallinity. Specifically, water-soluble acrylic resins such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl imidazole, and polyacrylic acid, gelatin, gum arabic, and the like are suitable. Among these, water can be applied as a solvent, and at the time of printing Polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl imidazole are preferable from the viewpoint that they are easily removed by the fountain solution. Among them, polyvinyl alcohol (PVA) gives the best results for basic properties such as oxygen barrier properties and development removability.

  The polyvinyl alcohol that can be used in the protective layer may be partially substituted with esters, ethers, and acetals as long as they contain a substantial amount of unsubstituted vinyl alcohol units having the required water solubility. Similarly, a part may contain other copolymerization components. For example, various hydrophilic modification sites such as anion modification sites modified with anions such as carboxyl groups and sulfo groups, cation modification sites modified with cations such as amino groups and ammonium groups, silanol modification sites, and thiol modification sites are randomly selected. Polyvinyl alcohol having various degrees of polymerization, the anion-modified site, the cation-modified site, the silanol-modified site, the thiol-modified site, the alkoxyl-modified site, the sulfide-modified site, and the ester modification of vinyl alcohol and various organic acids. Polyvinyl alcohol having various degrees of polymerization having various modified sites such as a site, an ester-modified site of the anion-modified site and alcohols, an epoxy-modified site, etc. at the polymer chain end is also preferably used.

  Suitable examples of the modified polyvinyl alcohol include compounds having a hydrolysis degree of 71 to 100 mol% and a polymerization degree in the range of 300 to 2400. Specifically, 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, L-8 and the like. Examples of the modified polyvinyl alcohol include KL-318, KL-118, KM-618, KM-118, SK-5102 having an anion-modified site, C-318, C-118 and CM-318 having a cation-modified site. M-205 and M-115 having terminal thiol modification sites, MP-103, MP-203, MP-102, MP-202 having terminal sulfide modification sites, and ester modification sites with higher fatty acids HL-12E, HL-1203, and other reactive silane-modified R-1130, R-2105, R-2130, and the like.

  The protective layer preferably contains a layered compound. A layered compound is a particle having a thin tabular shape, for example, the following general formula

A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂

[However, A is any of Li, K, Na, Ca, Mg, organic cation, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the formula 3MgO.4SiO.H ₂ O.

Examples of the natural mica include muscovite, soda mica, phlogopite, biotite and sericite. Further, as the synthetic mica, non-swelling mica such as fluorine phlogopite mica ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic mica NaMg _2.5 ( Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite-based Na or Li hectorite (Na, Li) _1/8 Mg _2/5 Li Examples thereof include swelling mica such as _1/8 (Si ₄ O ₁₀ ) F ₂ . Synthetic smectite is also useful.
Of the above layered compounds, fluorine-based swellable mica, which is a synthetic layered compound, is particularly useful. That is, swellable clay minerals such as mica, montmorillonite, saponite, hectorite, bentonite, etc. have a laminated structure composed of unit crystal lattice layers with a thickness of about 10 to 15 mm, and metal atom substitution in the lattice is other than Significantly greater than viscous minerals. As a result, the lattice layer has a shortage of positive charge, and in order to compensate for it, Li ⁺ , Na ⁺ , Ca ²⁺ , Mg ²⁺ , amine salts, quaternary ammonium salts, phosphonium salts, sulfonium salts, etc. Adsorbs organic cation cations. These layered compounds swell with water. If shear is applied in this state, it will easily cleave and form a stable sol in water. Bentonite and swelling synthetic mica have this tendency.

As the shape of the layered compound, from the viewpoint of diffusion control, the thinner the better, the better the plane size as long as the smoothness of the coated surface and the transmittance of actinic rays are not impaired. Therefore, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.
The average particle diameter of the layered compound is 1 to 20 μm, preferably 1 to 10 μm, particularly preferably 2 to 5 μm. When the particle diameter is smaller than 1 μm, the suppression of permeation of oxygen and moisture is insufficient and the effect cannot be exhibited sufficiently. On the other hand, if it is larger than 20 μm, the dispersion stability in the coating solution is insufficient, resulting in a problem that stable coating cannot be performed. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among the inorganic layered compounds, the size of the swellable synthetic mica that is a representative compound is about 1 to 50 nm in thickness and about 1 to 20 μm in surface size.

When particles of inorganic layered compound having a large aspect ratio are contained in the protective layer as described above, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Deterioration is prevented, and even when stored for a long time under high-humidity conditions, the storage stability of the planographic printing plate precursor does not deteriorate due to changes in humidity, and the storage stability is excellent.
It is preferable that content of the inorganic stratiform compound in a protective layer is 5/1-1/100 by mass ratio with respect to the quantity of the binder used for a protective layer. Even when a plurality of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

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 can be added. These activators can be added in an amount of 0.1 to 100% by mass relative to the (co) polymer.
In order to improve the adhesion to the image area, for example, JP-A-49-70702 and British Patent Application No. 1303578 disclose an acrylic polymer in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesion can be obtained by mixing 20 to 60% by mass of a water-based emulsion, a water-insoluble vinylpyrrolidone-vinyl acetate copolymer and the like, and laminating the mixture on an image recording layer. Any of these known techniques can be used in the present invention.

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, safe light is not caused. Suitability can be improved.
Next, an example of a general dispersion method of the layered compound used for the protective layer will be described. First, 5 to 10 parts by mass of the swellable laminar compound mentioned above as a preferred laminar compound is added to 100 parts by mass of water, and the mixture is thoroughly swelled and swollen, and then dispersed by a disperser. Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. A dispersion of 5 to 10% by mass of the inorganic stratiform compound dispersed by the above method is highly viscous or gelled and has very good storage stability. When preparing a protective layer coating solution using this dispersion, it is preferably prepared by diluting with water and stirring sufficiently, and then blending with a binder solution.

This protective layer coating solution includes known anionic surfactants, nonionic surfactants, cationic surfactants, fluorosurfactants and water-soluble plasticizers for improving the physical properties of coatings. Additives can be added. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer can also be added. Furthermore, a known additive for improving the adhesion with the image recording layer and the temporal stability of the coating solution may be added to the coating solution.
The protective layer coating solution thus prepared is applied onto the image recording layer provided on the support and dried to form the protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The method for applying the protective layer is not particularly limited, and a known method such as the method described in US Pat. No. 3,458,311 or Japanese Patent Publication No. 55-49729 can be applied. . Specific examples of the protective layer include blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, and bar coating.
The coating amount of the protective layer, the coating amount after drying is preferably in the range of 0.01 to 10 g / m ^2, more preferably in the range of 0.02 to 3 g / m ^2, and most preferably 0. The range is 02 to 1 g / m ² .

[Lithographic printing method]
In the present invention, the image recording layer coated and formed on the support gives a negative relief image to the original image by imagewise exposure with a laser or the like using digital data. As a light source suitable for exposure, an infrared laser is particularly preferable, and examples thereof include a solid-state laser and a semiconductor laser that emit infrared rays of 760 to 1200 nm.
The infrared laser used in the present invention preferably has an output of 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 μs. 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, the lithographic printing plate precursor of the present invention is imagewise exposed and then supplied with fountain solution and printing ink without any development process. .
Specifically, after a lithographic printing plate precursor is exposed with a laser, it is mounted on a printing machine without passing through a development process, and after printing the lithographic printing plate precursor on a printing machine, a laser is used on the printing machine. And a method of printing without passing through a development processing step.

<Printing device>
Here, the overall configuration of a printing apparatus that can be used for carrying out the lithographic printing method of the present invention will be described.
FIG. 1 shows a conceptual diagram of an example of a printing apparatus that can be used to implement the planographic printing method of the present invention.
A printing apparatus 10 shown in FIG. 1 is an on-press drawing / on-press development type lithographic printing apparatus that forms a printing plate on a machine and constitutes a CTC (computer-to-cylinder) system. , Impression cylinder 12, blanket cylinder (rubber cylinder) 14, plate cylinder 16, ink form roller 18, ink roller array 20, ink metering supply unit 22, image recording means 24, dampening water supply means 26, a dust removal device 28, and a main control device 30.

  In such a printing apparatus 10, first, the on-press development type plate material Ps is supplied onto the plate cylinder 16. When a used printing plate is held on the plate cylinder 16, the printing plate is discharged in advance before supplying the plate material Ps.

  Next, the image recording means 24 records an image on the plate material Ps held by the plate cylinder 16 based on the image data.

  Further, the dampening water supply means 26 supplies dampening water to the plate material Ps on which the image is recorded. In this state, some of the components are not removed in the non-image portion of the image recording layer of the plate material Ps.

  In one aspect of the present invention, the fountain solution supply means 26 includes a plate surface moisture content measuring device 46 and a fountain solution supply device 50.

  The plate surface moisture amount measuring device 46 measures the amount of dampening water (plate surface moisture amount) on the surface of the printing plate held on the plate cylinder 16, and is composed of a sensor 46a and a calculation unit 46b. It is an apparatus for measuring the amount of water. In the illustrated example, using the measurement result of the sensor 46 a, the calculation unit 46 b calculates the plate surface moisture amount and sends the result (plate surface moisture amount information) to the main controller 30.

  The amount of moisture on the plate surface supplied to the plate material increases with time, but eventually becomes saturated. If only watering is continued as it is, it will be developed on the machine gradually with only the watering roller, so the moisture content on the plate surface will decrease with the removal of the image recording layer. Shimese. In the present invention, the amount of water on the planographic printing plate precursor is measured in the step (ii), and when the specified amount of water is reached, the plate surface of the inking roller in the step (iii) is contacted. It is preferable to use the maximum value of the plate surface water amount as the prescribed water amount. That is, the main controller 30 monitors the plate surface moisture amount information sent from the plate surface moisture amount measuring device 46 and brings the inking roller into contact with the plate surface immediately before the on-press development by the water roller starts.

  In another aspect of the present invention, the dampening water supply means 26 includes a plate surface reflection infrared (IR) measuring device instead of the plate surface water content measuring device 46.

  The plate surface reflection IR measurement device measures the image recording layer on the surface of the printing plate held on the plate cylinder 16 and is a known reflection IR measurement device including an IR irradiation unit and a sensor. Using this, the IR spectrum of the lithographic printing plate precursor used in advance is measured, the peak that can be separated from the printing ink and fountain solution is specified, and whether or not the image recording layer at the time of watering is removed at this peak intensity. Can be monitored.

  Therefore, in this embodiment, there is no change in the IR absorption peak from the start of watering until the image recording layer is removed by the watering roller. Peak intensity decreases. In the present invention, the inking roller is brought into contact with the plate surface at the timing when the IR absorption peak intensity starts to decrease. That is, the main controller 30 monitors the IR absorption peak intensity sent from the plate surface reflection IR measuring device, and brings the inking roller into contact with the plate surface immediately before the on-press development by the water roller starts.

In this way, ink is supplied to the plate material Ps. Ink is supplied to the printing plate Ps by the ink metering supply unit 22 that transfers the ink to the ink roller row 20, the ink roller row 20 transfers the ink to the ink form roller 18, and the ink form roller 18 is held on the plate cylinder 16. This is done by transferring ink to the finished plate Ps. In this state, the image recording layer in the unexposed area is easily peeled off and transferred to the inking roller 18 by ink tack. The portion where the image recording layer is removed and the surface of the metal support is exposed is hydrophilic and is therefore covered with the fountain solution. As a result, the ink does not adhere. For this reason, the adhesion (dirt) of ink in the non-image portion of the plate material Ps decreases with time. Further, the unexposed image recording layer fragments removed at this time are made finer and harmless in the ink roller array 20. On the other hand, ink gradually adheres to the image area at the same time.
On the other hand, generally, the printing material M (for example, printing paper) is supplied almost simultaneously with the supply of the ink to the printing material Ps or after 2-3 rotations of the printing drum, and the ink is transferred to the printing material M. . Here, the ink on the printing material M is transferred by transferring the ink on the plate material Ps to the blanket cylinder 14, and the ink on the blanket cylinder 14 is conveyed while being sandwiched between the blanket cylinder 14 and the impression cylinder 12. This is performed by being transferred to the printing material M.

  In this way, while supplying dampening water and ink to the plate material Ps on which the image is recorded, the image recording layer of the plate material Ps is transferred while the ink on the plate material Ps is transferred to the printing material M. The non-image area is completely removed, that is, the plate material Ps is developed into a printing plate, and the ink attached only to the image area of the printing plate is transferred to the printing material M, and the non-image area is stained. No printed matter will be obtained.

  In FIG. 1, a monochromatic printing device 10 is illustrated for the sake of clarity of the configuration of the device, but the present invention is not limited to this, and a configuration corresponding to a printing device for four full-color images. And various other multicolor printing apparatuses.

Hereinafter, each configuration will be described in detail.
In the printing apparatus 10, the impression cylinder 12 and the blanket cylinder 14 are the same as those in a normal offset printing apparatus. Further, a known impression cylinder cleaning device 32 is disposed on the impression cylinder 12, and a known blanket cleaning device 34 is disposed on the blanket cylinder 14.

The ink metering supply unit 22 includes a known ink fountain I (ink fountain) including an ink discharge roller 36, an ink key 42 that contacts the ink discharge roller 36, and a blade 38 that contacts the ink key 42, and an ink transfer roller 40. And a motor 44 for driving the ink key 42.
The ink take-out roller 36 draws ink having a constant film thickness from the ink fountain I (that is, draws the ink by metering), and moves the ink to an ink transfer roller 40 that rotates in contact with the ink take-out roller 36.
In the ink metering supply unit 22 of the illustrated example, the film thickness (supply amount) of the ink drawn out by the ink discharging roller 36 is adjusted by adjusting the distance or pressing force between the tip of the ink key 42 and the ink discharging roller 36. . A plurality of ink keys 42 are provided in close contact with the rotation axis direction (width direction) of the ink discharge roller 36 (not shown), and the distance between the ink key 42 and the ink discharge roller 36 is individually adjusted by a motor 44. The The drive of the motor 44 that moves each ink key 42 and adjusts the distance from the ink discharge roller 36 is adjusted according to the ink key opening signal supplied from the main controller 30.

In the present invention, the ink metering means (metering means) is not limited to the ink metering unit 22 described above, and includes, for example, a configuration using an anix roller and a doctor blade, an ink ejection roller, an ink ejection roller, A configuration in which the rollers are arranged apart from each other and the interval and rotation speed thereof can be adjusted, and the ink fountain is formed between the two rollers. The ink ejection roller and the ink ejection roller are disposed in contact with each other. A well-known metering means such as a configuration using an ink fountain between both rollers using a roller whose speed can be adjusted can be used.
An ink metering unit having an ink key 42 like the ink metering unit 22 in the illustrated example is preferable in that the amount of ink supplied to the ink discharge roller 36 can be adjusted in the width direction.

  The ink transfer roller 40 is a driven roller whose rotation shaft is pivotally supported by the arm 40a. Further, the arm 40a is pivotally supported at the opposite end to the ink transfer roller 40 and is rotated by a drive source (not shown). The ink transfer roller 40 is moved to the ink roller row 20 side after ink is transferred in contact with the ink discharge roller 36 by rotating the arm 40a, and is moved to the top roller of the ink roller row 20. The ink transfer by contact is repeated according to a predetermined cycle or operation information.

  The configuration of the ink roller row 20 is not particularly limited and may be a conventionally known one, but generally includes an ink kneading roller, a kneading cylinder, a relay roller, and a horizontal roller. The ink transferred to the top roller of the ink roller array 20 is kneaded and uniformized while being transferred to each roller of the ink roller array 20, and then transferred to the ink form roller 18.

  As the dampening water supply device 50, a conventionally known device can be used. However, in the illustrated example, the water sump 52, the water source roller 54, the motor 56, the horizontal swing roller 58, and the swim roller 60 It is comprised. The horizontal roller 58 adjusts the water content in the width direction of the swim roller 60 by moving in the direction of the rotation axis.

The plate cylinder 16 may include a supply / discharge plate device (not shown) including a supply device for unexposed plate material Ps (unused plate material Ps) and a discharge device for used printing plates.
In the present invention, the supply / discharge plate apparatus is not particularly limited, and various means used in conventional printing apparatuses and CTC systems can be used. For example, as disclosed in JP 2000-211100 A, a cut sheet-shaped unexposed plate material is stored in a cassette and loaded into a predetermined position, and supplied to a plate cylinder using a roller, a guide, or the like. There is a supply / discharge plate means for holding and discharging the plate. In addition, when the cut sheet-like plate material is covered with an interleaf to protect the surface thereof, a means for removing the interleaf may be provided.

Further, when using a roll-shaped plate material, for example, a means for loading an unexposed plate material roll and a means for loading a winding roll for a used printing plate are provided, and the used printing plate is wound. At the same time, by unwinding the unexposed plate material from the plate material roll by winding it with the take-up roll, it is supplied from the plate material roll as described in JP-A-10-323963. Examples include a feeding / discharging plate means that pulls out a predetermined length of plate material, cuts it with a cutter, supplies / holds it to the plate cylinder, peels the used printing plate with a nail and discharges it with a pair of rollers.
Here, when the plate material Ps is fed out from inside and wound around the plate cylinder 16 and wound inside, the plate material Ps having relatively low rigidity and strength is preferably used when feeding and discharging plates are performed simultaneously. In this case, in order to prevent the printing plate from being stretched or displaced during printing, the plate cylinder 16 preferably has a plate displacement preventing means. The plate misregistration preventing means is not particularly limited, and known means can be used. For example, a method of roughening the surface of the plate cylinder 16 and a method of using an under-plate sheet having a roughened surface that comes into contact with the plate material may be used.

  In any case, the supply of the plate material to the plate cylinder, the holding of the plate material on the plate cylinder, the discharge of the used printing plate from the plate cylinder, and the like can be performed by known methods.

  The image recording unit 24 records an image on the plate material Ps held by the plate cylinder 16 and includes an image recording control device 64 and an image recording device 66.

  The image recording control means 64 drives the image recording device 66 according to the image data supplied from the external image data supply source and the operation information sent from the main control device 30.

The image recording device 66 records an image on the plate material Ps by a recording method corresponding to the image recording layer of the on-press development type plate material Ps.
As the image recording device 66, a conventionally known device can be suitably used as long as the plate material Ps forms an image by heating. For example, a recording apparatus that performs imagewise exposure by scanning a light beam such as an infrared laser modulated according to a recorded image and records the image by heating by photothermal conversion can be used.
Such image recording by the image recording device 66 is performed while rotating (ie, scanning) the plate cylinder 16 holding the unexposed plate material Ps at a predetermined speed corresponding to image recording. Thereby, an image can be recorded two-dimensionally on the plate material Ps. At the time of image recording, the ink form roller 18 and the blanket cylinder 14 may be separated from the plate cylinder 16. This separation may be performed by moving either the ink form roller 18 or the plate cylinder 16.

The dust removing device 28 is a means for removing dust such as dust existing on the plate material surface before and / or during image recording on the plate material. The dust removing device 28 can effectively prevent the ink from adhering to the non-image portion of the plate material along the dust.
As the dust removal device 28, a conventionally known device can be used. For example, an apparatus that performs removal by a non-contact method such as suction removal, blow-off removal, electrostatic removal, or the like; removal by a contact method using a brush, a roller, or the like can be given. In the present invention, suction removal with air, blow-off removal with air, and a combination thereof are preferable. In this case, an air pump usually used for a paper feeding device can be used for this purpose.
As shown in the figure, the dust removing device 28 is preferably provided immediately in front of the image recording device 66 in the direction in which the plate cylinder 16 rotates.
In the illustrated example, the printing apparatus 10 includes the dust removal device 28, but may not include the dust removal device.

The main control device 30 controls the operation of the entire printing apparatus 10. Then, the main control device 30, based on the detection results from various sensors arranged at the respective positions of the printing device 10, displays the operation information, the plate surface moisture amount measuring device 46 (calculation unit 46 b), image recording control. It supplies to the device 64 and the like.
In the CTC system that performs full-color image printing of four colors, the main controller 30 performs various image processing such as color / density correction, color image processing on image data supplied from an external image data supply source. Various processes such as separation of C (cyan), M (magenta), Y (yellow), and K (black) into monochrome images may be performed.

  The sensors arranged in each part of the printing apparatus 10 are usually arranged in a conventional printing apparatus, a conventional plate making apparatus, an on-board drawing type printing apparatus, an on-machine development type printing apparatus, or the like. For example, a sensor that detects the rotation of each cylinder and a sensor that detects the rotational position of each cylinder. The operation information specifically includes, for example, the plate cylinder rotational speed, the number of printing copies, the operating state of the printing apparatus, and the rotational position of the plate cylinder.

Hereinafter, the operation of the printing apparatus 10 including the description of the main controller 30 will be described.
First, the supply / discharge plate apparatus is operated to discharge the used printing plate on the plate cylinder 16 and hold the unexposed plate material Ps on the plate cylinder 16.

In parallel, main controller 30 sends an image data supply signal to an external image data supply source.
Based on the image data supply signal, the image data of the print image (converted into the scan line image data for halftone image recording) is sent from the external image data supply source to the image recording control device 64.

  Next, the main controller 30 rotates the plate cylinder 16 at a predetermined speed corresponding to image recording. Further, the image recording control device 64 drives the image recording device 66 in accordance with the operation information supplied from the main control device 30 (for example, the rotational speed of the plate cylinder, the rotational position of the plate cylinder), for example, as described above. An image is recorded on the plate material Ps held on the plate cylinder 16 by light beam scanning such as an infrared laser.

When the image recording is completed, the main controller 30 starts rotation of each roller from the ink discharge roller 36 to the impression cylinder 12 and prepares to supply ink to the plate surface of the plate material Ps. When this preparation is completed, the dampening water is supplied to the plate surface of the plate material Ps on which the image is recorded by the dampening water supply device 50.
At the same time, measurement of the moisture content of the plate surface or the IR absorption peak intensity is started. The main controller 30 monitors the plate surface state, and inking is performed at the timing when on-press development is started by the watering roller, that is, when the moisture content on the plate surface reaches a maximum or when the IR absorption peak intensity starts to decrease. The roller supplies ink to the plate surface of the plate material Ps.
On-press development proceeds rapidly by this inking roller, and the hydrophilic aluminum support surface is exposed in the non-image area.
The printing material M is supplied from a paper feeding device (not shown) almost simultaneously with or slightly behind the supply of the ink, and the printing material M is sandwiched between the blanket cylinder 14 and the impression cylinder 12. Then, the printing is started, and printing (trial printing in printing) is started. The produced printed matter is discharged to a predetermined position by a paper discharge device (not shown). In the printing apparatus 10, as the paper feeding device and the paper discharging device, known devices used in various printing devices can be used.

  Further, based on the plate surface moisture amount information measured by the moisture amount measuring device 46 and sent to the main controller 30, the main controller 30 determines whether the plate surface moisture amount is appropriate or not, and according to the result. The dampening water supply device 50 can also be controlled. Specifically, when the plate surface moisture amount is appropriate, the dampening water supply amount is maintained, and when the plate surface moisture amount is too large, the dampening water supply amount is decreased and the plate surface moisture amount is too small. In some cases, increase the dampening water supply. Thereby, automation of dampening water supply control is achieved.

  Further, during printing, an ink key opening signal is sent to the ink metering supply unit 22 (motor 44), and the motor 44 determines the ink supply amount in accordance with the ink key opening signal and turns the ink key 42 on. Control.

  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.

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

(Examples 1-24 and Comparative Examples 1-13)
1-1. Production of planographic printing plate precursor (1) (1) Production of support In order to remove rolling oil on the surface of a 0.3 mm thick aluminum plate (material 1050), a 10 mass% sodium aluminate aqueous solution is used at 50 ° C. After degreasing for 30 seconds, the aluminum surface was grained using ^three bundled nylon brushes with a bristle diameter of 0.3 mm and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) with a median diameter of 25 μm. And washed well with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in 20 mass% nitric acid at 60 ° C for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power supply waveform is electrochemical roughening treatment using a trapezoidal rectangular wave AC with a time TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave AC. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode.
The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode. Then, water washing by spraying was performed.

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. The plate was provided with a DC anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolytic solution, then washed with water and dried.
Then, in order to ensure the hydrophilic property of a non-image part, the silicate process was performed for 12 second at 70 degreeC using 1.5 mass% sodium silicate aqueous solution. The adhesion amount of Si was 7 mg / m ² . Then, it washed with water and the support body was obtained. The centerline average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

Furthermore, the following undercoat liquid (1) was applied so that the dry coating amount was 20 mg / m ² to prepare a support used in the following experiments.

Undercoat liquid (1)
・ Undercoat compound (1) below 0.017g
・ Methanol 9.00 g
・ Distilled water 1.00g

(2) Formation of image recording layer On the support having the above-mentioned undercoat layer, an image recording layer coating solution (1) having the following composition was bar coated, followed by oven drying at 100 ° C. for 60 seconds to obtain a dry coating amount of 1. An image recording layer of 3 g / m ² was formed. The image recording layer coating solution (1) was obtained by mixing and stirring the following photosensitive solution (1) and microgel solution (1) immediately before coating.

Photosensitive solution (1)
-0.185 g of the following binder polymer (1)
・ The following infrared absorber (1) 0.030 g
・ The following polymerization initiator (1) 0.180 g
・ Polymerizable compound (Aronix M315, manufactured by Toagosei Co., Ltd.) 0.385 g
-0.044 g of the following fluorosurfactant (1)
・ Methyl ethyl ketone 1.091g
・ 1-methoxy-2-propanol 8.609g

Microgel solution (1)
-Microgel (1) synthesized as follows: 2.640 g
・ Distilled water 2.425g

(Synthesis of microgel (1))
As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N) 10 g, pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., SR444) 3.15 g, And 0.1 g of Pionein A-41C (manufactured by Takemoto Yushi Co., Ltd.) 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 12,000 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 50 ° C. for 3 hours. The solid content concentration of the microgel solution thus obtained was diluted with distilled water so as to be 15% by mass. The average particle size was 0.2 μm.

(3) Formation of Protective Layer After the protective layer coating solution (1) having the following composition was bar-coated on the image recording layer, it was oven-dried at 125 ° C. for 75 seconds and a dry coating amount of 0.15 g / m ^2. A protective layer was formed so that the lithographic printing plate precursor (1) used in Examples 1 to 4, 13 to 16 and Comparative Examples 1 to 5 was obtained.

Protective layer coating solution (1)
-1.5 g of inorganic layered compound dispersion (1) prepared as follows
・ Polyvinyl alcohol (Poval PVA105) 0.05g
・ Nonionic surfactant 0.01g
(Product name: EMALEX 710, manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 6.0g

(Preparation of inorganic layered compound dispersion (1))
6.4 g of synthetic mica Somasif ME-100 (manufactured by Coop Chemical Co., Ltd.) was added to 193.6 g of ion-exchanged water, and dispersed using an homogenizer until the average particle size (laser scattering method) became 3 μm. The aspect ratio of the obtained dispersed inorganic particles was 100 or more.

1-2. Preparation of lithographic printing plate precursor (2) A lithographic printing plate except that the image recording layer coating solution (1) described in the preparation of the lithographic printing plate precursor (1) is changed to an image recording layer coating solution (2) having the following composition: The lithographic printing plate precursor (2) used in Examples 5 to 8, 17 to 20 and Comparative Examples 6 and 7 was obtained in the same manner as the preparation of the precursor (1).

Image recording layer coating solution (2)
・ The following infrared absorber (2) 0.05 g
・ 0.20g of the above polymerization initiator (1)
・ 0.50 g of the above binder polymer (1)
Polymerizable compound, Aronix M-215 (manufactured by Toa Gosei Co., Ltd.) 1.00 g
・ Victoria Pure Blue Naphthalenesulfonate 0.02g
・ The following low molecular weight hydrophilic compound (1) 0.015 g
・ 0.020 g of the above fluorosurfactant (1)
・ Methyl ethyl ketone 18.0g

1-3. Preparation of lithographic printing plate precursor (3) A lithographic printing plate precursor (1) except that the protective layer coating solution (1) described in the preparation of the lithographic printing plate precursor (1) is changed to a protective layer coating solution (2) having the following composition. In the same manner as in 1), a lithographic printing plate precursor (3) used for 8 and 9 was obtained.

Protective layer coating solution (2)
・ Polyvinyl alcohol (Poval PVA105) 0.10g
・ Polyvinylpyrrolidone (K-30) 0.01g
(Wako Pure Chemical Industries, Ltd., mass average molecular weight 400,000)
・ Nonionic surfactant 0.01g
(Product name: EMALEX 710, manufactured by Nippon Emulsion Co., Ltd.)
・ Ion-exchanged water 6.0g

1-4. Preparation of lithographic printing plate precursor (4) A non-process plate “Thermal Direct” commercially available from Kodak Polychrome Graphics Co., Ltd. was used as it was as a lithographic printing plate precursor (4).

1-5. Preparation of lithographic printing plate precursor (5) A chemicalless plate “Azura” commercially available from Japan Agfa Gebalt Co., Ltd. was used as it is as a lithographic printing plate precursor (5).

2. Evaluation of planographic printing plate precursors 2-1. On-machine developability evaluation The obtained lithographic printing plate precursors (1) to (5) were subjected to Fujifilm's Luxel PLANETSETTER T-6000III equipped with an infrared semiconductor laser, with an outer drum rotation speed of 1000 rpm, a laser output of 70%, Image exposure exposure was performed under conditions of a resolution of 2400 dpi. The exposure image includes an FM halftone dot image having a small dot size of 20 μm.
The obtained exposed original plate was attached to a cylinder of a Speedmaster 52 printing machine manufactured by Heidelberger Drugmaschinen AG without developing. Dampening water (Ecocity-2 (manufactured by FUJIFILM Corporation) / water = 2/98 (volume ratio) with 3% IPA added) and Fusion (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) Were prepared in a dampening water circulation tank and an ink fountain, respectively, and prepared for printing. This printing press is equipped with the plate surface moisture content measuring device shown in FIG. 1 or the image recording layer IR absorption measuring device as shown in Table 1, and the plate surface state (moisture content or image recording layer of the original recording plate mounted above). Amount) can be measured in real time.
After completion of preparation for printing, the operation of the printing press was started. First, the dampening water was supplied to the printing plate by bringing the watering roller into contact with the plate at the slip rate and water supply scale shown in Table 1. At the same time, the monitoring of the plate surface started.
Next, when the moisture content on the plate surface reached a maximum, or when the image recording layer on the plate surface began to be removed, the inking roller was brought into contact with the plate surface, and the supply of printing ink was started. The number of plate cylinder rotations from the watering roller contact to the inking roller contact is shown in Table 1 as “watering number”. The number of plate cylinder rotations “inking times” from when the printing paper is fed to when printing starts from the contact of the inking roller is set to 3 as the default value of the printing press setting.
Printing was started in such a start sequence, the water supply scale was automatically switched to 40% determined in advance according to the image area, and 200 sheets were printed at a printing speed of 8000 sheets per hour.
When the on-press development of the unexposed part of the image recording layer was completed on the printing press and the number of printing paper required until the ink was not transferred to the printing paper was measured as on-press developability, the following table was obtained. 2 results were obtained.

2-2. Evaluation of printing durability After evaluating on-press developability as described above, the ink amount was adjusted so that the solid ink density (reflection density) of the printing paper was 1.9 with a Gretag densitometer, Printing was further continued while adjusting the amount of dampening water supplied so that the non-image area of the printing paper was not smudged with ink. As the number of printed sheets was increased, the image recording layer was gradually worn out and the ink acceptability was lowered, so that the ink density in the printing paper was lowered. Printing durability was evaluated based on the number of printed sheets when the solid ink density (reflection density) decreased by 0.2 from the start of printing. The results are shown in Table 2.

2-3. Development residue adhesion evaluation After the above on-press development property evaluation, before starting the printing durability evaluation, the printing press is temporarily stopped, and development residue (solid state) is formed on the 100th printed material, on the ink kneading roller, on the blanket, and on the plate. Whether or not the development removal product was attached) was observed using a microscope (VHX-100, zoom lens VH-Z150, manufactured by Keyence Corporation) at a magnification of 500 times. The results were evaluated using the following indices. The results are shown in Table 2 below.

<Development residue adhesion evaluation index>
A: No development residue adhered B: Development residue of several tens of μm or less adhered very slightly. Acceptable level.
C: Development debris of 50 μm or more adheres and NG level D: Development debris of 100 μm or more adheres, and development debris can be easily confirmed with the naked eye.

2-4. Evaluation of fountain solution contamination After the above-mentioned printing durability evaluation, the state of fountain solution contamination by the developer removal component was observed and evaluated according to the following indices. The results are shown in Table 2.

<Dampening water contamination evaluation index>
A: No contamination B: Acceptable level with only slight coloration C: Clearly colored and NG level D: Clearly colored and solid development residue mixed

  As is apparent from Table 2, according to the planographic printing method of the present invention, good on-press developability even if the printing press conditions such as the watering roller / plate cylinder slip ratio and the water supply scale during watering fluctuate. It can be seen that all of the above can be achieved stably, with good printing durability, suppression of on-machine development residue, and suppression of dampening solution contamination.

Schematic diagram of an example of a printing apparatus that can be used in the planographic printing method of the present invention

Explanation of symbols

10 Printing device 12 Impression cylinder
14 Blanket cylinder (rubber cylinder)
16 Plate Cylinder 18 Ink Forming Roller 20 Ink Roller Row 22 Ink Meter Supply Unit 24 Image Recording Means 26 Dampening Water Supply Means 28 Dust Removal Device 30 Main Control Device 32 Pressure Cylinder Cleaning Device 34 Blanket Cleaning Device 36 Ink Removal Roller 38 Blade 40 Ink transfer roller 40a Arm 42 Ink key 44 Motor 46 Plate surface moisture content measuring device 46a Sensor 46b Calculation unit 50 Dampening water supply device 52 Water reservoir 54 Water source roller 56 Motor 58 Horizontal swing roller 60 Swim roller 64 Image recording control device 66 Image Recording device

Claims (6)

A lithographic printing method having the following steps (i) to (iv), wherein the amount of water on the lithographic printing plate precursor is measured in the step (ii), and when the specified amount of water is reached (iii) A lithographic printing method comprising performing a step.
(I) A lithographic printing plate precursor having an image recording layer developed film-developing by supplying printing ink and / or dampening water on a support is mounted on a plate cylinder of a printing machine, Or after imagewise exposure and mounting on a plate cylinder of a printing press;
(Ii) supplying dampening water or dampening water and printing ink from a watering roller to the lithographic printing plate precursor after exposure;
(Iii) Next, supplying printing ink from an ink roller to the lithographic printing plate precursor to remove unexposed portions;
(Iv) A printing step.   2. The lithographic printing method according to claim 1, wherein the specified water content is a water content that maximizes the water content measured in the step (ii). A lithographic printing method having the following steps (i) to (iv), wherein the removal amount of the image recording layer of the lithographic printing plate precursor is measured in the step (ii) and the removal starts (iii) A lithographic printing method comprising the steps of:
(I) A lithographic printing plate precursor having an image recording layer developed film-developing by supplying printing ink and / or dampening water on a support is mounted on a plate cylinder of a printing machine, Or after imagewise exposure and mounting on a plate cylinder of a printing press;
(Ii) supplying dampening water or dampening water and printing ink from a watering roller to the lithographic printing plate precursor after exposure;
(Iii) Next, supplying printing ink from an ink roller to the lithographic printing plate precursor to remove unexposed portions;
(Iv) A printing step.   The lithographic printing method according to claim 1 or 3, wherein the image recording layer contains (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound.   The lithographic printing method according to claim 4, wherein the image recording layer further contains (D) a binder polymer that does not dissolve in the fountain solution.   The lithographic printing method according to any one of claims 1 to 5, wherein the moisture content on the original plate is measured using a plate surface reflection infrared measuring device.

Images