JP2005246966A - Laminate for lithographic printing plate precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate for lithographic printing plate precursors improved in scratch resistance at the time of transportation and exposure and capable of recording an image by infrared lasers and on-press development. <P>SOLUTION: The laminate 12 for the lithographic printing plate precursors formed by alternately laminating the precursors for the lithographic printing plate 10 and interleaving sheets 14. The lithographic printing plate precursors 10 comprise an image recording layer containing (A) an infrared absorber, (B) a polymerization initiator and (C) polymerizable compound on an aluminum support having a roughened surface-treated. The image recording layer is capable of being removed with a printing ink and/or damping water. The dynamic friction coefficient is 0.25-0.70 between the outermost surface of the lithographic printing plate precursors 10 and the interleaving sheets 14 in the laminate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminate of a lithographic printing plate precursor. More specifically, the present invention relates to a laminate of a lithographic printing plate precursor and a slip sheet that can record an image by scanning an infrared laser based on a digital signal from a computer or the like and can be developed on the 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). In this method, a difference in ink adhesion is caused on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, conventionally, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Normally, after exposing a lithographic printing plate precursor through an original image such as a lithographic film, the image recording layer in the image area is left, and the image recording layer in the non-image area is dissolved with an alkaline developer or an organic solvent. The lithographic printing plate is obtained by carrying out plate making by a method of exposing the surface of the hydrophilic support by removing it.

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

  On the other hand, the non-processing (non-development) type that eliminates the need for wet processing has an image recording layer whose affinity for dampening water or ink changes on the surface by exposure and is accompanied by removal of the image recording layer. A lithographic printing plate precursor that can be printed without any problem has been proposed.

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

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

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

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

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

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

Patent Documents 2 and 3 describe lithographic printing plate precursors containing microcapsules encapsulating a polymerizable compound on a hydrophilic support.
Furthermore, Patent Document 4 describes a lithographic printing plate precursor in which a photosensitive layer containing an infrared absorber, a radical polymerization initiator, and a polymerizable compound is provided on a support.
These documents describe that the printing durability can be improved by using a polymerization reaction to increase the chemical bond density of the image area as compared with the image area formed by thermal fusion of polymer fine particles. Yes.
Japanese Patent No. 2938397 JP 2001-277740 A JP 2001-277742 A JP 2002-287334 A

  In general, when transporting a plurality of lithographic printing plate precursors, a laminate in which interleaf sheets having a function of protecting a coating layer such as an image recording layer and a protective layer from mechanical impacts are sandwiched between the lithographic printing plate precursors Means for forming the body are used. However, in the on-press development type lithographic printing plate precursor utilizing the above polymerization reaction, the image recording layer contains a large amount of low-molecular components and the like, so that the image strength before exposure is low, and it is transported or exposed. The scratch resistance was insufficient. For example, when transporting the laminate of the lithographic printing plate precursor and the slip sheet, or when setting the laminate in an exposure machine having an autoloader and peeling the slip sheet, between the outermost surface of the coating layer and the slip sheet In some cases, the outermost surface was scratched by the friction. When scratches occur, an undesired curing reaction occurs in the non-image area, resulting in scratched print stains, or in the image area, the curing reaction is insufficient and the image is scratched. White spots may occur.

  That is, an object of the present invention is to provide a laminate of a lithographic printing plate precursor having improved scratch resistance during transportation and exposure and capable of image recording with an infrared laser and development on the machine.

When the coefficient of dynamic friction between the slip sheet and the outermost surface of the lithographic printing plate precursor is within a specific range, the present inventors have found that the lithographic printing plate precursor laminate is stored, transported, and scratches or scratches related to the autoloader of the exposure machine. The present inventors have found that it is possible to prevent both white spots and dirt caused by the present invention, and have completed the present invention.
That is, the present invention is as follows.
1. Image recording that contains (A) an infrared absorber, (B) a polymerization initiator and (C) a polymerizable compound on a roughened aluminum support and can be removed by printing ink and / or dampening water. A laminated body in which lithographic printing plate precursors and slip sheets having layers are alternately stacked and accumulated, and a dynamic friction coefficient between the outermost surface of the lithographic printing plate precursor and the slip sheet is 0.25 to 0.70. A lithographic printing plate precursor laminate comprising:

  2. 2. The lithographic printing plate as described in 1 above, wherein the image recording layer contains microcapsules containing at least one selected from (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound. Printing plate precursor laminate.

  3. 3. The lithographic printing plate precursor laminate as described in 1 or 2 above, wherein the image recording layer comprises (D) inorganic particles.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated body of the lithographic printing plate precursor which can carry out image recording with the infrared laser and which can carry out on-machine development improved the flaw resistance at the time of conveyance and exposure.

The planographic printing plate precursor laminate of the present invention comprises (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound on a roughened aluminum support, and includes printing ink and And / or a laminate in which a planographic printing plate precursor having an image recording layer removable by a dampening solution and interleaving paper are alternately stacked and accumulated, and between the outermost surface of the planographic printing plate precursor and the interleaving paper The coefficient of dynamic friction is 0.25 to 0.70.
Here, the outermost surface of the lithographic printing plate precursor means the outermost surface on the image recording layer side of the lithographic printing plate precursor. That is, when there is no further coating layer on the image recording layer, it means the surface of the image recording layer, and when there is a further coating layer such as a protective layer on the image recording layer, it means the surface of the coating layer.
Hereinafter, the laminate will be described in detail.

[Interleaf]
As the interleaving paper used in the present invention, it is preferable to select a low-cost raw material in order to reduce material costs. For example, paper using 100% by mass of wood pulp or synthetic pulp mixed with wood pulp is used. The used paper, and paper having a low density or high density polyethylene layer provided on the surface thereof can be used. In particular, a paper that does not use a synthetic pulp or a polyethylene layer has a low material cost, so that a slip sheet can be produced at a low cost. Specifically, the bleached kraft pulp is beaten, and the sizing agent is added to the paper stock diluted to a concentration of 4% by weight so that the base paper weight is 0.1% by weight and the paper strength agent is 0.2% by weight. Furthermore, it is a paper made by using a paper material in which aluminum sulfate is added until the pH becomes 5.0, and its basis weight (JIS P81
9 to 60 g / m ² , preferably 35 to 50 g / m ² , and the thickness (according to the measurement method defined in JIS P 8118) is 42 to 80 μm, preferably 45 to 65 μm. More preferably, it is 45 to 55 μm, and the chemical requirement is that a sample of 20 g is cut into 100 g of pure water, sealed and heated at 110 ° C. for 10 minutes, and then a NH ₃ gas detection method using a Kitagawa gas detector tube (for 20 ppm). Chloride detection in which NH ₃ gas is not detected and 3 ml of slip paper sample is placed in 6 ml of distilled water, and 2 drops of 1% by weight silver nitrate solution is dropped into it to observe the presence or absence of chloride turbidity. In the method, an interleaving paper in which white turbidity is not recognized is preferable. Further, regarding the mechanical and strength characteristics, the preferable requirements for the slip sheet are shown in Table 1 together with the above-described filling degree and chemical requirements, but are not limited thereto.
For example, instead of using the above-mentioned aluminum sulfate as a filler and using a rosin-based sizing agent corresponding thereto, neutral paper combining a calcium carbonate filler and an alkyl ketene dimer-based sizing agent can be used as a slip sheet.

The notes in the measurement method column of Table 1 are as follows.
(Note 1) The difference between the maximum value and the minimum value obtained by measuring the thickness of an arbitrary position of one sheet in accordance with JIS P 8118.
(Note 2) When the dimension (A) dried for 1 hour at 110 ° C. and the dimension (B) left for 3 hours at 20 ° C. and 65% RH, “stretch degree (rate) = (B · A) / Expansion rate represented by “A × 100”.
(Note 3) The slip sheet is cut into a 150 mm × 150 mm sheet, and this sheet is left in an environment of a temperature of 20 ° C. and a humidity of 65% RH for 3 hours or more. The volume resistance value (Rv) is measured by a capacitive universal electrometer (MMAI 17 and P-601), and the product of the volume resistance value (Rv) and the electrode area (19.62 cm ² ) of the measuring device. Volume specific resistance value (ρv) obtained from the relationship of ρv = 19.62 / t × Rv by removing the slip sheet thickness (t) from
(Note 4) The mount is cut into a sheet of 150 mm × 150 mm, and this sheet is left for 3 hours or more in an environment of a temperature of 20 ° C. and a humidity of 65% RH. Surface resistance values were measured with a type universal electrometer (MMAII · 17 and P · 601). Surface specific resistance value (ρs) obtained by ρs = 18.7 × Rs from the product of the surface resistance value (Rs) and a coefficient (18.7) calculated from the electrode area of the measuring instrument.
(Note 5) Static friction coefficient with the image forming surface of a lithographic printing plate.
(Note 6) A value measured with a Kitagawa type gas detector tube (for 20 ppm) after cutting 20 g of a sample into 100 g of pure water and heating at 110 ° C. for 10 minutes.
(Note 7) Put 3 ml of slip paper sample in 6 ml of distilled water, drop 2 drops of 1% by mass silver nitrate solution into it, and visually check for cloudiness.

Among the specifications of the slip sheets described above, preferable specifications include a basis weight of 30 to 60 g / m ² , a smoothness of 10 to 100 seconds by a Beck smoothness measuring method defined in JIS8119, and a moisture content of JIS8127. It is 4 to 8% by mass and the density is 0.7 to 0.9 g / cm ³ by the specified moisture content measurement method.

[Dynamic friction coefficient of the lithographic printing plate precursor on the top of the slip sheet]
In the present invention, the physical friction coefficient between the interleaving paper and the lithographic printing plate precursor, which is advantageous because both physical defects such as white spots and troubles during operation of the autoloader can be reduced, is 0.25 to 0.7. It is a range, More preferably, it is the range of 0.30-0.65. If the upper limit of this specific range is exceeded, scratches tend to occur. Does not decrease. Since the operability is inferior when slippery, the dynamic friction coefficient is more preferably 0.33 or more, and preferably 0.68 or less in order to facilitate the removal operation of the interleaf. More preferably, the coefficient of dynamic friction is set to 0.35 to 0.65 from the standpoint of easy setting of the plate, countermeasures against rubbing when taking out with the arm, avoidance of the influence of the wind of the fan, and the like.

  The means for controlling the dynamic friction coefficient within the above-mentioned range can be performed in either or both of the lithographic printing plate precursor and the interleaf. Moreover, it can carry out by any of surface lubrication treatment and adjustment of the composition of the lithographic printing plate precursor and / or slip sheet. That is, nonionic and amphoteric surfactants for image recording layers, fluorine-containing copolymers and other slipping agents, sizing agents such as rosin added to interleaving paper and, in some cases, alkyl ketene dimers, It can be easily performed by selecting each type and adjusting the content. Further, the slipping paper can be subjected to an impregnation treatment with an aqueous solution of a surfactant or a lubricant solution represented by glyceride of stearic acid to control the friction characteristics. Further, it is possible to control the friction characteristics by controlling the surface roughness, and therefore, it is also possible to control the calendering temperature and the applied pressure conditions in the papermaking process.

  Any known method can be used as the method for measuring the dynamic friction coefficient of the slip sheet with respect to the surface of the lithographic printing plate precursor. In particular, the method presented in JIS P8147 is simple and practically accurate. It is preferable because it is possible. In the test, measurement is performed on the outermost surface of the lithographic printing plate precursor and the surface of the slip sheet that is actually in contact with the outermost surface.

[Laminate]
The lithographic printing plate precursor according to the invention is alternately laminated with the above-mentioned interleaving paper to form a laminate. Further, this laminate is shipped, transported and stored in a form in which it is packaged.
The lithographic printing plate packaging structure for making the laminate into a packaging form may or may not have a contact ball and interior paper. In addition to normal cardboard box packaging, the lithographic printing plate precursor on the skid Skid type packaging in which the laminate is placed and packaged, and paper pallet type packaging in which the laminate is placed and packaged on a paper pallet are also included.
Hereinafter, specific examples of the planographic printing plate packaging structure will be described with reference to the drawings.

As shown in FIG. 1, the planographic printing plate packaging structure 18 is formed by alternately laminating interleaf paper 14 and the planographic printing plate precursor 10, and further hitting balls 22 on the upper and lower surfaces (the requirements of the hitting ball are the above described interleaf paper). The same as that described as the requirement of (1). The laminated body 12 is wrapped with an interior paper 16 which is still another example of the slip sheet.
The number of lithographic printing plate precursors 10 constituting one laminate 12 is not particularly limited, but is preferably 10 to 100, for example, from the viewpoints of transportation and storage efficiency and ease of mounting on an automatic plate making machine. . When the laminate 12 is composed of 10 to 100 lithographic printing plate precursors 10, the lithographic printing plate precursor 10 and the contact balls 22 are fixed by a fixing means such as an adhesive tape so as not to be displaced from each other. It is preferable. Further, the laminated bundle 12 may be constituted by several thousand lithographic printing plate precursors 10. In the laminate 12, the contact balls 22 may be inserted for every 20 to 100 lithographic printing plate precursors 10, or the contact balls 22 may be arranged only above and below the laminate 12.
Further, the contact ball 22 can be omitted in any of the laminated bodies 12.

After wrapping the laminated body 12 thus configured with the interior paper 16, the adhesive paper 24 is used to prevent the interior paper 16 from unintentionally spreading or dropping off, as shown in FIG. A lithographic printing plate packaging structure 18 is configured by fixing the folding portion. Thereby, the planographic printing plate 10 is reliably shielded from light and moisture by the interior paper 16.
The planographic printing plate packaging structure 18 may be housed in an exterior box and packaged or loaded on a pallet as necessary.

[Lithographic printing plate precursor]
The lithographic printing plate precursor according to the invention contains (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound on a roughened aluminum support, and includes printing ink and / or Alternatively, it has an image recording layer that can be removed by dampening water. The components of the planographic printing plate precursor will be described below.

((A) infrared absorber)
In the image recording layer of the present invention, an infrared absorber is used in order to increase sensitivity to an infrared laser. The infrared absorber has a function of converting absorbed infrared rays into heat. 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 and JP-A-58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, Naphthoquinone dyes described in JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., and squarylium dyes described in JP-A-58-112792, etc. And cyanine dyes described in British Patent 434,875.

In addition, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also suitable. ) Pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, and 58-2
Pyryllium compounds described in 2014, No. 59-41363, No. 59-84248, No. 59-84249, No. 59-146063, No. 59-146061, JP-A-59-216146 The cyanine dyes described herein, the pentamethine thiopyrylium salts described in US Pat. No. 4,283,475, and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. It is done. Another example of a preferable dye is a near-infrared absorbing dye described in U.S. Pat. No. 4,756,993 as formulas (I) and (II).
Other preferable examples of the infrared absorbing dye 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 preferred, and one particularly preferred example is a cyanine dye represented by the following general formula (I).

In the general formula (I), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below. 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. Here, the hetero atom represents N, S, O, a halogen atom, or Se. Xa ⁻ is defined in the same manner as Za ⁻ described later, and R ^a is a hydrogen atom, an alkyl group,
It represents a substituent selected from an aryl group, a 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 from the viewpoint of storage stability of the recording layer coating solution, and particularly preferably a perchlorate ion, a hexagonal ion. Fluorophosphate ions and aryl sulfonate ions.

Specific examples of 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 Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle diameter of the pigment is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 1 μm, and particularly preferably in the range of 0.1 to 1 μm. Within this range, good stability of the pigment dispersion in the image recording layer coating solution and good uniformity of the image recording layer can be obtained.

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

These infrared absorbers may be added to the same layer as other components, or another layer may be provided and added thereto. Moreover, it can also be included in a microcapsule and added.
As the addition amount, when a negative lithographic printing plate precursor is prepared, the absorbance at the maximum absorption wavelength in the wavelength range of 760 nm to 1200 nm of the image recording layer is in the range of 0.3 to 1.2 by the reflection measurement method. It is preferable to add such that it is in a range of 0.4 to 1.1. Within this range, a uniform polymerization reaction in the depth direction of the image recording layer proceeds, 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. Examples of the polymerization initiator that can be used in the present invention include known thermal polymerization initiators, compounds having a bond with small bond dissociation energy, and photopolymerization initiators. Among these, the polymerization initiator suitably used in the present invention is a compound that generates radicals by thermal energy. Hereinafter, the polymerization initiator used in the present invention will be described more specifically. Such polymerization initiators may be used alone or in combination of two or more.

  Examples of such polymerization initiators include organic halogen compounds, carbonyl compounds, organic peroxides, azo polymerization initiators, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, organic boron compounds, disulfone compounds, oxime esters. Compounds and onium salt compounds.

  Specific examples of the organic halogen compound include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Patent Publication No. 46-4605, JP 48-36281, JP 53-133428, JP 55-3070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62- 58241, JP-A 62-212401, JP-A 63-70243, JP-A 63-298339, P. Examples thereof include compounds described in Hutt "Journal of Heterocyclic Chemistry", 1 (No. 3), (1970). Of these, oxazole compounds and S-triazine compounds substituted with a trihalomethyl group are preferred.

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

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

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

  Examples of the organic peroxide 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 Japanese Patent Publication No. 6-29285, U.S. Pat. Nos. 3,479,185, 4,311,783, and 4,622.
Various compounds described in each specification of No. 286, specifically 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2 ′ -Bis (o-
Bromophenyl)) 4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 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)- Examples include 4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, and the like.

  Examples of the organic boron compounds include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, JP-A-2000-. No. 131837, JP 2002-107916 A, JP 2764769 A, JP 2002-116539 A, 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 The organoboron iodonium complex described in JP-A-9-188710, the organoboron phosphonium complex described in JP-A-9-188710, JP-A-6-348011, JP-A-7-128785, JP-A-7-140589, JP-A-5-140589 Examples thereof 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 2003-328465.

Examples of the oxime ester compounds include JCS Perkin II (1979) 1653-1660), JCS
Perkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, compounds described in JP-A No. 2000-66385, compounds described in JP-A No. 2000-80068, specifically, And a compound represented by the structural formula:

  Examples of the onium salt compound include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980), ammonium salts described in US Pat. No. 4,069,055, JP-A-4-365049, etc., US Pat. No. 4,069 , 055, 4,069,056, phosphonium salts described in European Patent Nos. 104,143, U.S. Pat. Nos. 339,049, 410,201, The iodonium salts described in the publications of Kaihei 2-150848 and JP-A-2-296514, European Patents 370,693, 390,214, 233,567, 297,443, No. 297,442, U.S. Pat. Nos. 4,933,377, 161,811, 410,201, 339,049, 4,760,0 No. 13, No. 4,734,444, No. 2,833,827, German Patent No. 2,904,626, No. 3,604,580, No. 3,604,581 A sulfonium salt described in each specification; 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.

  Particularly preferred from the standpoint of reactivity and stability are the oxime ester compounds or onium salts (diazonium salts, iodonium salts or sulfonium salts).

The onium salts suitably used in the present invention are represented by the following general formulas (RI-I) to (RI-III)
It is an onium salt represented by.

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, specifically a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, a sulfate ion Can be mentioned. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion and sulfinate ion are preferable from the viewpoint of stability.

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 include 1 to 1 carbon atoms. 12 alkyl groups, 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, Halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon Examples thereof include a thioalkyl group having 1 to 12 carbon atoms and a thioaryl group having 1 to 12 carbon atoms. Z ₂₁ ^- represents a monovalent anion, a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, sulfate ion, stability, From the viewpoint of reactivity, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, and carboxylate ions are preferable.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ are each independently an aryl group having a carbon number of 20 or less, an alkyl group, an alkenyl group or an alkynyl group which may have 1 to 6 substituents. Represents. Among them, an aryl group is preferable from the viewpoint of reactivity and stability. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, 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, C1-C12 aryloxy group, halogen atom, C1-C12 alkylamino group, C1-C12
A dialkylamino group having 1 to 12 carbon atoms, an amide group having 1 to 12 carbon atoms or an arylamide group, a carbonyl group, a 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. It is done. Z ₃₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoints of stability and reactivity. 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.

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

((C) polymerizable compound)
The polymerizable compound 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.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, 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 And sorbitol tetritaconate. Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include, for example, Japanese Patent Publication No. 51-47334, Japanese Patent Laid-Open No. 57-19.
Aliphatic alcohol esters described in Japanese Patent No. 6231, those having an aromatic skeleton described in Japanese Patent Laid-Open Nos. 59-5240, 59-5241, and 2-226149, Those containing an amino group described in Kaihei 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-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 (II) 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 (II)
(However, R ₄ and R ₅ represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, and 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. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the case, it is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

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

About these addition 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 portion, that is, the cured film, those having three or more functionalities are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrene compound, vinyl ether type). A method of adjusting both sensitivity and strength by using a compound) is also effective.
Further, the selection and 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 an overcoat 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 addition polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, etc. Depending on the case, a layer configuration and coating method such as undercoating and overcoating can be performed.

(Microcapsule)
In the present invention, an uneven structure is formed on the surface of the image recording layer by adding microcapsules to the image recording layer, and the dynamic friction coefficient between the slip sheet and the surface of the image recording layer can be controlled.
The average particle size of the microcapsules is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, a good dynamic friction coefficient, resolution, and stability over time can be obtained.

  Other substances added to the image recording layer such as the above (A) infrared absorber, (B) polymerization initiator, (C) polymerizable compound, colorant and print-out agent described later, and the like are included in the microcapsule. Any of the compounds that can be included may be used, but it is preferable that a low molecular weight component that increases the dynamic friction coefficient is included in the microcapsule. Among them, it is more preferable to encapsulate at least one of (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound, and in particular, (C) the polymerizable compound has fluidity at room temperature. Since it has many things and has a high tendency to increase the dynamic friction coefficient, it is most preferable to enclose them.

The substance to be included may include a part of the amount necessary for the image recording layer, or may include all. From the viewpoint of the dynamic friction coefficient, when a low molecular weight compound is included, it is preferable that the ratio of inclusion is high.
The form of the microcapsule may be a core-shell structure in which the substance to be encapsulated is completely separated from the microcapsule wall, or may be a form that is compatible and contained in the microcapsule wall. From the viewpoint of the dynamic friction coefficient, it is preferable to adopt a core-shell structure in which the low molecular weight compound is reliably separated.
As described above, by using the microcapsule, both the effect of making the image recording layer uneven and the inclusion of the low molecular weight component can be obtained, and the necessary coefficient of the low molecular weight component is ensured in the image recording layer, while the dynamic friction coefficient is secured. Can be controlled low.

  A known method can be applied as a method for microencapsulating the constituent components of the image recording layer. For example, as a method for producing microcapsules, a method using coacervation found in each specification of US Pat. No. 2,800,547 and US Pat. No. 2,800,498, US Pat. No. 3,287,154, Japanese Patent Publication No. 38-19574, 42-446 by the interfacial polymerization method, US Pat. Nos. 3,418,250 and 3,660,304, methods by polymer precipitation, and US Pat. No. 3,796,669. A method using a natto polyol wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, urea found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802, Formaldehyde or urea formaldehyde-resorcino A method using a wall-based wall forming material, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, as described in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method by monomer polymerization, spraying 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 However, it is not limited to these.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as an ethylenically unsaturated bond which can be introduce | transduced into the below-mentioned binder polymer.

(Other image recording layer components)
In the image recording layer of the present invention, addition of inorganic fine particles, slip agent, binder polymer, surfactant, colorant, bake-out agent, polymerization inhibitor, higher fatty acid derivative, plasticizer, low molecular weight hydrophilic compound, etc. An agent can be contained as needed. These will be described below.

<Inorganic fine particles>
Inorganic fine particles are a particularly useful additive because they are added to the image recording layer to form a concavo-convex structure on the surface of the image recording layer and control the dynamic friction coefficient between the slip sheet and the surface of the image recording layer. This is particularly effective when the content of the low molecular weight polymerizable compound is large and the surface of the image recording layer is sticky. By reducing the contact area with the interleaving paper and inserting an air layer between the interleaving paper, there is an effect of reducing the dynamic friction coefficient.
The inorganic fine particles are also effective in improving the strength of the cured film in the exposed area and in the on-press developability in the unexposed area.

As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate, or a mixture thereof is preferably exemplified.
The inorganic fine particles preferably have an average particle diameter of 0.1 to 10 μm, and more preferably 0.1 to 3 μm. Within the above range, it is stably dispersed in the image recording layer to form a concavo-convex structure on the surface of the image recording layer, to improve the film strength of the image recording layer, and to have a hydrophilic property that hardly causes stains during printing. Can be formed.
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 40% by mass or less, and more preferably 30% by mass or less, based on the total solid content of the image recording layer.

<Slip agent>
A slipping agent can be added to the image recording layer of the present invention. As a slip agent, conventionally well-known slip agents, such as a nonionic surfactant and an amphoteric surfactant containing a fluorine atom and a silicon atom, and a wax, can be mentioned, for example. Furthermore, the coefficient of dynamic friction can be controlled by adding a compound having a long-chain alkyl group exhibiting orientation on the surface of the image recording layer to the image recording layer coating solution. Furthermore, the dynamic friction coefficient can also be controlled by adding a compound represented by the general formula (1) described in JP-A No. 2002-296768. The dynamic friction coefficient of these additives can be easily controlled by adjusting the selection and content of each type. However, if the content of the slip agent is too large, the coefficient of dynamic friction with the slip sheet becomes too small, and the transportability may be impaired. Therefore, the content is preferably 0.05 to 8.0% by mass, more preferably 0.1 to 7.0% by mass with respect to the total solid content constituting the image recording layer.

<Binder polymer>
The image recording layer of the present invention can contain a binder polymer. As the binder polymer, any conventionally known polymer can be used without limitation, and a polymer having a film property is preferable. Examples of such binder polymers include acrylic resins, polyvinyl acetal resins, polyurethane resins, polyurea resins, polyimide resins, polyamide resins, epoxy resins, methacrylic resins, polystyrene resins, novolac phenolic resins, polyester resins, and synthetic rubbers. And natural rubber.
The binder polymer 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 and poly-1,4-isoprene.
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 ethylene. Examples thereof include polymers having a polymerizable 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, or an alkyl group having 1 to 20 carbon atoms, an aryl group, and alkoxy. R ¹ and R ² or R ³ may be bonded to each other to form a ring, n represents an integer of 1 to 10. X represents a dicyclopentadienyl residue. Represents a group).
Specific examples of the ester _{residue, -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.

The binder polymer having crosslinkability, for example, has a free radical (polymerization initiation radical or a growth radical in the polymerization process of the polymerizable compound) added to the crosslinkable functional group, and the polymerization chain of the polymerizable compound is formed directly between the polymers. Through addition polymerization, a cross-link is formed between the polymer molecules and cured. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded together, thereby causing cross-linking between polymer molecules. Forms and cures.
The content of the crosslinkable group in the binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1.0, per 1 g of the binder polymer. -7.0 mmol, most preferably 2.0-5.5 mmol. Within this range, good sensitivity and good storage stability can be obtained.

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

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

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

The binder polymer preferably has a weight average molecular weight of 5000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more, preferably 2000 to 250,000. More preferred. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The binder polymer may be any of a random polymer, a block polymer, a graft polymer, and the like, but is preferably a random polymer.

The binder polymer can be synthesized by a conventionally known method. Solvents used in the synthesis include, for example, 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.
As the radical polymerization initiator used for synthesizing the binder polymer, known compounds such as an azo initiator and a peroxide initiator can be used.

A binder polymer may be used independently or may be used in mixture of 2 or more types.
The content of the binder polymer is 5 to 90% by mass, preferably 5 to 80% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the image recording layer. Within this range, good image area strength and image formability can be obtained.
Moreover, it is preferable to use (C) polymeric compound and binder polymer in the quantity used as 1 / 2-7 / 2 by mass ratio.

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

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

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

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

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

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

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 7% 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) Manufactured by Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in Japanese Patent No. 293247. In addition, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can also be suitably used.

  These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The addition amount is 0.01 to 10% by mass with respect to the total solid content of the image recording material.

<Polymerization inhibitor>
In order to prevent unnecessary thermal polymerization of the (C) radical polymerizable compound during production or storage of the image recording layer, it is preferable to add a small amount of a thermal polymerization inhibitor to the image recording layer of the present invention.
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.

<Low molecular hydrophilic 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 compounds include water-soluble organic compounds such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol and the like, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and the like Examples thereof include organic carboxylic acids such as salts, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid and amino acids, and salts thereof.

(Formation of image recording layer)
The image recording layer of the present invention is coated 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, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The image recording layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeating a plurality of coatings and dryings.

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 characteristics of the image recording layer can be obtained.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

(Support)
The support used for the lithographic printing plate precursor according to the invention is a roughened aluminum support.
The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign 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 from 0.1 to 0.6 mm, and more preferably from 0.15 to 0.4 mm.

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 thus cannot be specified in general. However, in general, an electrolyte concentration of 1 to 80% by mass solution, a liquid temperature of 5 to 70 ° C., a current density of 5 to 60 A / 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, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. In addition, if necessary, the micropore enlargement treatment, the micropore sealing treatment, and the hydrophilic compound described in JP-A-2001-253181 and JP-A-2001-322365 are contained. A surface hydrophilization treatment immersed in an aqueous solution to be performed can be selected as appropriate.

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.

  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.

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

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

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

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

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

As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added.
The thickness of the protective layer is suitably 0.05 to 4.0 μm, particularly preferably 0.1 to 2.5 μm.

  In addition, adhesion to the image area, scratch resistance, and the like are extremely important in handling the lithographic printing plate precursor. That is, when a protective layer that is hydrophilic because it contains a water-soluble polymer compound is laminated on an image recording layer that is oleophilic, the protective layer is easily peeled off due to insufficient adhesion, and polymerization is inhibited by oxygen at the peeled portion. It may cause defects such as poor film hardening due to.

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

[Exposure and printing of planographic printing plate precursor]
The planographic printing plate precursor of the present invention is imagewise exposed with an infrared laser.
Although the infrared laser used for this invention is not specifically limited, Wavelength 760-1200n
A solid laser and a semiconductor laser emitting m infrared rays are preferable. The output of the infrared laser is preferably 100 mW or more. In order to shorten the exposure time, it is preferable to use a multi-beam laser device.
The exposure time per pixel is preferably within 20 μsec. Moreover, it is preferable that irradiation energy amount is 10-300 mJ / cm < ² >.

The lithographic printing plate precursor according to the invention is used for lithographic printing using an oil-based ink and an aqueous component without any development processing steps after imagewise exposure with an infrared laser.
Specifically, after exposing the lithographic printing plate precursor with an infrared laser, mounting it on a printing machine without passing through the development process, printing the lithographic printing plate precursor on the printing machine, Examples include a method of printing with an infrared laser and printing without going through a development process.

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

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

(Examples 1-7 and Comparative Examples 1-3)
[Production of slip paper]
<Interleaf 1>
Bleached kraft pulp was beaten and 0.4% by mass of rosin sizing agent was added to the paper stock diluted to a concentration of 4% by mass, and aluminum sulfate was added until the pH reached 5.0. The paper stock was coated with 3.0% by weight of a paper strength agent mainly composed of starch, and paper was made. Beck smoothness of the surface in contact with the outermost surface on the negative recording layer side was 60 seconds, and the density was 0.8 g / cm. ³ , interleaf paper 1 having a water content of 6.0% by mass and a basis weight of 38 g / m ² was prepared. The main points of the specifications of the slip sheet 1 are shown in Table 2.

<Interleaf 2>
As interleaving paper 2, Beck smoothness of the surface in contact with the outermost surface on the negative recording layer side made from the raw material of hardwood bleached kraft pulp 100% by mass using the same sizing agent and fixing agent, about 500 seconds, Paper having a density of 0.8 g / cm ³ , a moisture content of 4.5% by mass, a pH of 5.5, and a basis weight of 30 g / m ² was used. The main points of the specifications of the slip sheet 2 are shown in the table below.

[Preparation of lithographic printing plate precursor]
<Production of support>
In order to remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, a degreasing treatment was performed at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, and then a hair diameter of 0.3 mm was obtained. The aluminum surface was grained using three bundle-planted nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed thoroughly 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 source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio 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 alternating current. 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. This plate was provided with a direct current anodic oxide coating 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 electrolyte, then washed with water and dried. Furthermore, it processed at 30 degreeC for 10 second with 2.5 mass% sodium silicate aqueous solution. 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.

<Formation of image recording layer>
The image recording layer coating liquids (1) to (5) having the following composition were sequentially applied onto the support by a bar and then oven-dried at 100 ° C. for 60 seconds to obtain an image having a dry coating amount of 1.0 g / m ² . A recording layer was formed to obtain lithographic printing plate precursors (1) to (5).

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

Image recording layer coating solution (2)
・ Water 24.3g
・ Propylene glycol monomethyl ether 86.1g
・ Methyl ethyl ketone 10.9g
-The following microcapsule (1) (15% by mass aqueous solution) 26.4 g
・ 1.0 g of the above polymerization initiator (1)
・ 0.2g of the above infrared absorber (1)
・ The above binder polymer (1) (average molecular weight 80,000) 1.6 g
・ Polymerizable compound 3.9 g
Isocyanuric acid EO-modified triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester M-315)
・ Victoria Pure Blue Naphthalenesulfonate 0.01g
-0.8g of said fluorosurfactant (1) (10 mass% aqueous solution)

(Synthesis of microcapsule (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, 0.35 g of the following infrared absorber (1), 1 g of 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane (ODB manufactured by Yamamoto Kasei), and Pionin A-41C (Takemoto Yushi Co., Ltd.) ) 0.1 g was dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 3 hours. The microcapsule solution thus obtained was diluted with distilled water so that the solid content concentration was 15% by mass. The average particle size was 0.3 μm.

Image recording layer coating solution (3)
・ Water 23.5g
・ Propylene glycol monomethyl ether 86.1g
・ Methyl ethyl ketone 10.9g
・ The above microcapsule (1) (15% by mass aqueous solution) 26.4 g
・ 1.0 g of the above polymerization initiator (1)
・ The above infrared absorber (1) 0.2 g
-Binder polymer (1) (average molecular weight 80,000) 1.0 g
・ Polymerizable compound 3.9 g
Isocyanuric acid EO-modified triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester M-315)
・ Inorganic fine particle colloidal silica (40% by mass aqueous solution) 1.4 g
(Nissan Chemical Industry Co., Ltd., Snowtex MP-2040,
Particle size 0.2μm)
・ Victoria Pure Blue Naphthalenesulfonate 0.01g
-0.8g of said fluorosurfactant (1) (10 mass% aqueous solution)

Image recording layer coating solution (4)
・ Water 24.3g
・ Propylene glycol monomethyl ether 86.1g
・ Methyl ethyl ketone 10.9g
・ The above microcapsule (1) (15% by mass aqueous solution) 26.4 g
・ 1.0 g of the above polymerization initiator (1)
・ 0.2g of the above infrared absorber (1)
-Binder polymer (1) (average molecular weight 80,000) 1.0 g
・ Polymerizable compound 3.9 g
Isocyanuric acid EO-modified triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester M-315)
・ Slip agent (dodecyl stearate) 0.6g
・ Victoria Pure Blue Naphthalenesulfonate 0.01g
-0.8g of said fluorosurfactant (1) (10 mass% aqueous solution)

Image recording layer coating solution (5)
・ Water 24.3g
・ Propylene glycol monomethyl ether 86.1g
・ Methyl ethyl ketone 10.9g
・ The above microcapsule (1) (15% by mass aqueous solution) 26.4 g
・ 1.0 g of the above polymerization initiator (1)
・ 0.2g of the above infrared absorber (1)
-Binder polymer (1) (average molecular weight 80,000) 1.0 g
・ Polymerizable compound 3.9 g
Isocyanuric acid EO-modified triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester M-315)
・ Slipper (dodecyl stearate) 1.2g
・ Victoria Pure Blue Naphthalenesulfonate 0.01g
-0.8g of said fluorosurfactant (1) (10 mass% aqueous solution)

[Production and evaluation of laminates]
The obtained interleaving papers 1 and 2 and the lithographic printing plate precursors (1) to (5) are combined as shown in Table 3, and the laminated paper and the lithographic printing plate precursor are alternately laminated to produce a laminate, The scratch resistance and transportability were evaluated by the following methods. The evaluation results are shown in Table 3.

(Scratch resistance)
The formed laminate is set in a cassette of an exposure machine (manufactured by CREO, Trendsetter VX), and the exposure unit is exposed on the exposure machine by an autoloader from the setting part (exposure condition: output 9 W, outer drum rotation speed 210 rpm, resolution 2400 dpi). Then, it was transported to a stocker, and the obtained exposed original plate was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg without developing. Dampening solution (EU-3 (Etch solution manufactured by Fuji Photo Film Co., Ltd.) / Water / isopropyl alcohol = 1/89/10 (volume ratio)) and TRANS-G (N) black ink (Dainippon Ink & Chemicals, Inc.) After supplying dampening water and ink, 500 sheets were printed at a printing speed of 6000 sheets per hour. It was confirmed that the on-press development was completed in all the examples and comparative examples up to 500 sheets. And about this 500th printed matter, it visually observed whether there was a stain | pollution | contamination of the non-image part resulting from an abrasion, or a white spot of an image part, and it was set as the index | index of damage resistance.
○: Neither scratch-like dirt nor white spots are observed.
Δ: Scratch-like dirt or white spots are faintly seen.
X: There are scratch-like dirt or white spots.

(Evaluation of transportability)
On the vibrating device (Kudo Ace Co., Ltd., manufactured by Kudo Ace Co., Ltd.) kept horizontally, the formed laminate was stacked at a height of 15 cm, vibrated with a vibration dial scale 60 for 10 minutes, and then the planographic printing plate precursor The horizontal displacement (mm) is measured, and the value is used as an evaluation scale.

  From the above results, in the comparative example in which the dynamic friction coefficient is outside the scope of the present invention, at least one of scratch resistance or transportability is inferior, whereas in the examples in which the dynamic friction coefficient is within the scope of the present invention, the scratch resistance, It can be seen that the transportability is also excellent. In particular, it was shown that the use of microcapsules and inorganic fine particles was particularly excellent.

It is a figure which shows the example of a packaging structure of the lithographic printing plate precursor laminated body of this invention. It is a figure which shows the example of a packaging structure of the lithographic printing plate precursor laminated body of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Planographic printing plate precursor 12 Laminated body 14 Interleaf paper 16 Interior paper 18 Planographic printing plate precursor packaging structure 22 Contact ball 24 Adhesive tape

Claims (3)

  Image recording that contains (A) an infrared absorber, (B) a polymerization initiator and (C) a polymerizable compound on a roughened aluminum support and can be removed by printing ink and / or dampening water. A laminated body in which lithographic printing plate precursors and slip sheets having layers are alternately stacked and accumulated, and a dynamic friction coefficient between the outermost surface of the lithographic printing plate precursor and the slip sheet is 0.25 to 0.70. A lithographic printing plate precursor laminate comprising:   The image recording layer contains microcapsules containing at least one selected from (A) an infrared absorber, (B) a polymerization initiator, and (C) a polymerizable compound. A planographic printing plate precursor laminate.   The lithographic printing plate precursor laminate according to claim 1 or 2, wherein the image recording layer contains (D) inorganic particles.

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