JP2007076330A - Original plate for planographic printing plate, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an original plate for a planographic printing plate, which solves the problem that stains appear on a paper surface corresponding to an end of the original plate for the planographic printing plate, which makes setter conveyability good, which dispenses with a step of removing a slip sheet and which can enhance the productivity of a plate-making operation, and a manufacturing method for the original plate for the planographic printing plate. <P>SOLUTION: In this manufacturing method for the original plate for the planographic printing plate, the original plate for the planographic printing plate is manufactured by cutting a coated web with a cutting member in the state of sandwiching the coated web in the direction of plate thickness. In the coated web, a photosensitive layer and a protecting layer containing an inorganic layered compound are laminated on an aluminum substrate with a hydrophilic surface in this order. The manufacturing method is characterized in that the coated web is cut without making the slip paper interposed between the coated surfaces of the coated web. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a photopolymerizable photosensitive lithographic printing plate precursor and a lithographic printing plate precursor obtained thereby, and more specifically, a photopolymerizable photosensitive lithographic printing plate precursor in which no smear occurs at the end, and It relates to the manufacturing method.

As a method for producing a lithographic printing plate precursor using an aluminum plate as a support, a method is generally employed in which a coated web formed by applying and drying a photosensitive solution is cut into a desired size. At the edge of the cut negative lithographic printing plate precursor, the photosensitive layer is polymerized and cured by the high pressure at the time of cutting. As a result, the commercial value of the printed matter was significantly impaired.
As a lithographic printing plate precursor having a good setter transportability and a method for producing the same, a method for controlling the shape of the lithographic printing plate precursor after cutting to a predetermined condition has been proposed (for example, (See Patent Document 1). Here, only the cutting with interleaving paper is disclosed, and when the interleaving paper is removed and cut under the same conditions, a new problem arises that the occurrence of edge stains cannot be suppressed.

Conventionally, as a lithographic printing plate precursor to be subjected to an exposure step, a laminate in which a slip sheet is inserted between the original plate and the original plate has been used. The interleaving paper has a function of preventing adhesion between the original plates and improving the transportability of the setter and a function of preventing the protective layer from being scratched. However, in order to increase the efficiency of the plate making operation, it has been desired to omit the slip sheet removing step using a laminate that does not insert slip sheets. Further, not using the slip sheet brings advantages such as cost reduction and reduction of environmental burden.
For this reason, the lithographic printing plate precursor that prevents the edge of the printing plate due to the cutting process from occurring without interposing the interleaf and has good setter transportability and does not require the interleaf removal process. And a method for producing the same.
JP 2003-63161 A

  The object of the present invention in consideration of the above-mentioned problems is that a planographic printing plate that suppresses stains on the paper surface corresponding to the edge of the planographic printing plate precursor due to the cutting process, has good setter transportability, and does not require a slip sheet removing process An object of the present invention is to provide a method for producing an original plate and a lithographic printing plate precursor in which the occurrence of stains at the edge obtained by the production method is suppressed.

The present inventors have found that the above object can be solved by controlling a cutting method of a coated web having a specific protective layer, and have completed the present invention.
That is, in the method for producing a lithographic printing plate precursor according to the present invention, a coated web obtained by laminating a photosensitive layer and a protective layer containing an inorganic layered compound in this order on an aluminum support having a hydrophilic surface is formed using a cutting member. A method for producing a lithographic printing plate precursor produced by being sandwiched in a direction and being cut, wherein the cutting is carried out without interposing a slip sheet on the surface of the protective layer of the coated web.
The cutting member used here has a pair of upper and lower cutting blades, the interval between the upper cutting blade and the lower cutting blade is set in a range of 30 to 100 μm, and the coating web is cut into a predetermined size. The photosensitive layer is preferably a polymerizable negative type containing (b) an infrared absorber, (b) a polymerization initiator, (c) a polymerizable compound, and (d) a binder polymer.

The lithographic printing plate precursor that has been cut under the above conditions has two or four opposite ends curved from the photosensitive layer side to the lower surface side from the viewpoint of improving setter transportability, and the surface along the ends. A curved surface formed by bending in a direction away from the curved surface, a cutting sag height of the curved portion in a cross section is 30 to 200 μm, and a cutout area of the curved portion is 200 to 100,000 μm ² To do.

That is, the present invention has been found and completed as follows. When the interval between the upper blade and the lower blade for cutting the lithographic printing plate precursor is set between 30 to 100 μm and cut into a predetermined size, the cut lithographic printing plate precursor has two sides facing the cutting portion or It has a curved surface formed by being bent in the direction away from the surface along the edges of the four sides, the cutting sag height of the curved portion in the cross section is 30 to 200 μm, and the cutout area of the curved portion is 200 It is ˜100,000 μm ² and has a shape excellent in setter transportability.
In order to achieve such a shape, a general negative-type photosensitive layer and a water-soluble protective layer are cut under the above-described cutting conditions without cutting a slip sheet between the coating web and the cutting blade. In the planographic printing plate precursor having the above, the occurrence of stains at the edge of the paper surface during printing cannot be suppressed, but in the present invention. Since the protective layer contains an inorganic stratiform compound, no dirt is generated even if it is cut without intervening paper. The reason that the edge contamination does not occur is not clear, but by including an inorganic layered compound in the protective layer, the protective layer is cracked due to the physical properties of the inorganic layered compound having a laminated structure in a plate shape at the time of cutting. It is considered that oxygen can permeate slightly from that portion to reach the photosensitive layer, and undesired polymerization of the cut portion due to the active species generated during cutting can be suppressed.

  A mica compound is preferable as the inorganic layered compound from the viewpoint of appropriately generating cracks in the protective layer of the cut portion and suppressing the stain on the paper end. From the same point of view, the inorganic layered compound has a smaller shape as the thickness is reduced, and the plane size is preferably larger as long as the smoothness of the coated surface and the transmittance of actinic rays are not impaired. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  According to the present invention, a method for producing a lithographic printing plate precursor that suppresses stains on the paper surface corresponding to the edge of the lithographic printing plate precursor due to the cutting step, has good setter transportability, and does not require an interleaf removal step, and It is possible to provide a lithographic printing plate precursor in which the occurrence of contamination at the edge obtained by the production method is suppressed.

The present invention is produced by cutting a coated web in which a photosensitive layer and a protective layer containing an inorganic stratiform compound are laminated in this order on an aluminum support having a hydrophilic surface, and sandwiching the coated web in the thickness direction with a cutting member. A method for producing a lithographic printing plate precursor, comprising: cutting the coated web on the coated surface without interposing a slip sheet. The present invention will be described in further detail.
First, a method for cutting the coated web will be described.

  FIG. 1 is a cross-sectional view showing a cutting portion of the slitter device. In the slitter device, a pair of upper and lower cutting blades 10 and 20 are arranged on the left and right. These cutting blades 10 and 20 are circular blades on a circular plate, and the upper cutting blades 10a and 10b are supported on the rotating shaft 11 and the lower cutting blades 20a and 20b are supported on the rotating shaft 21 coaxially. The upper cutting blades 10a and 10b and the lower cutting blades 20a and 20b are rotated in opposite directions. The planographic printing plate precursor 30 is cut into a predetermined width by passing between the upper cutting blades 10a and 10b and the lower cutting blades 20a and 20b. More specifically, the gap between the upper cutting blade 10a and the lower cutting blade 20a and the upper blade between the upper cutting blade 10b and the lower cutting blade 20b in the cutting section of the slitter apparatus shown in FIG. The target end cross-sectional shape can be obtained by adjusting the amount of biting (S) of the lower blade. From the viewpoint of suppressing the occurrence of edge contamination on the paper surface and suppressing the occurrence of automatic conveyance failure in the laser exposure setter, the clearance between the upper cutting blade 10a and the lower cutting blade 20a and the clearance between the upper cutting blade 10b and the lower cutting blade 20b. (D) is preferably set to 30 to 100 μm and cut, and 40 to 80 μm is a more preferable range. Furthermore, from the viewpoint of preventing distortion of the printing plate precursor, the amount of biting (S) between the upper blade and the lower blade is preferably set to 50 to 1000 μm, and more preferably 200 to 700 μm.

  FIG. 2 shows the shapes of the upper cutting blade 10a and the lower cutting blade 20a of the present invention. FIG. 3 is an enlarged view of part A in FIG. 2 and shows the tip shape of the upper cutting blade 10a and the tip shape of the lower cutting blade 20a and the gap between the upper cutting blade and the lower cutting blade. FIG. 4 shows the shape of an end cross-section cut using the slitter device of FIG. 1 and the cutting blade of FIG.

The shape of the notch in FIG. 4 is preferably curved in a convex shape, more preferably a convex curve without a bent portion. In the case of having a bent portion, ink may adhere to the bent portion and stains may occur. A preferable range of the sagging height (X) in FIG. 4 is 30 to 200 μm, and a more preferable range is 40 to 180 μm, from the viewpoint of suppressing the occurrence of edge contamination on the paper surface and suppressing the occurrence of poor automatic conveyance with a laser exposure setter. . From the same viewpoint, the preferable range of the area of the notch in FIG. 4 (Y) is 200～100000Myuemu ^2, a more preferred range is 500~70000μm ^2. The sagging height (X), the area of the notch (Y), and the burr height (Z) can be measured with an ultra-deep shape measuring microscope VK-8500 (manufactured by Keyence).

<Lithographic printing plate precursor>
Next, a planographic printing plate precursor to which the production method of the present invention is applied will be described. In the lithographic printing plate precursor according to the invention, a photosensitive layer and a protective layer containing an inorganic layered compound are provided in this order on an aluminum support. Here, “provided in this order” means that a photosensitive layer and a protective layer containing an inorganic stratiform compound are provided in this order on the support, and other layers (for example, a back surface) provided according to the purpose. It does not deny the presence of a coat layer or the like.

[Protective layer]
The characteristics of the protective layer suitable for the lithographic printing plate precursor include that the paper is cut without intervening intervening paper to cause moderate cracking so that the edges do not become smudged, do not hinder the transmission of actinic rays used for exposure, and gas A film or a film having low permeability can be formed, and the adhesiveness with the photosensitive layer is excellent. In addition, when the printing plate precursors are stacked without interposing the interleaving paper, it is also necessary to have a characteristic of preventing the occurrence of feeding errors and scratches on the surface of the protective layer during setter conveyance due to adhesion between the printing plate precursors. As a result of intensive studies, the present inventors have found that a protective layer exhibiting excellent performance can be obtained by using an inorganic layered compound having the following physical properties together with a suitable binder.

The inorganic layered compound used in the present invention is a particle having a thin flat plate shape. For example, a mica group such as natural mica and synthetic mica represented by the following general formula (1), general formula (2) Talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by
General formula (1): A (B, C) ₂ -5D ₄ O ₁₀ (OH, F, O) ₂ [where A is any of K, Na, and Ca, and B and C are Fe (II) , Fe (III), Mn, Al, Mg, V, and D is Si or Al. ]
General formula (2): 3MgO · 4SiO · H2O

In the mica group, examples of natural mica include muscovite, soda mica, phlogopite, biotite and sericite. Synthetic mica includes non-swelling mica such as fluorine phlogopite mica ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 (Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic mica NaMg _2.5. (Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite-based Na or Li hectorite (Na, Li) _1/8 Mg _2/5 Examples thereof include swelling mica such as Li _1/8 (Si ₄ O ₁₀ ) F ₂ . Synthetic smectite is also useful.

  In the present invention, among the inorganic layered compounds, fluorine-based swellable mica, which is a synthetic inorganic layered compound, is particularly useful. Among them, bentonite and swellable synthetic mica are useful, and swellable synthetic mica is particularly preferably used.

  As the shape of the inorganic layered compound used in the present invention, from the viewpoint of controlling the permeability of molecules to the protective layer and controlling the diffusibility of molecules within the protective layer, the thinner the better, the plane size is As long as the smoothness of the coated surface and the transmittance of actinic rays are not impaired, the larger the better. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  As for the particle diameter of the inorganic stratiform compound used in the present invention, the average major axis is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among the inorganic layered compounds, the size of the swellable synthetic mica, which is a representative compound, has a thickness of 1 to 50 nm and a surface size of about 1 to 20 μm.

  When particles of inorganic layered compounds having a large aspect ratio are contained in the protective layer as described above, the coating film strength is improved and the permeation of oxygen and moisture can be effectively prevented. Even when stored for a long time under high humidity conditions, the storage stability of the planographic printing plate precursor is not deteriorated due to changes in humidity, and the storage stability is excellent. Furthermore, as described above, when cutting with a cutting blade, the protective layer is difficult to bend, and there is also an advantage that the protective layer that can permeate oxygen to suppress undesired polymerization is likely to be cracked.

  The amount of the inorganic layered compound contained in the protective layer is preferably 5/1 to 1/100 by weight with respect to the amount of the binder used in the protective layer. If the amount of the inorganic layered compound is less than 1/100 in the weight comparison example, there is no effect of adding the inorganic layered compound, and if it exceeds 5/1, the coating film may be cracked. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-mentioned weight ratio.

  The binder used in the protective layer of the present invention is not particularly limited as long as it has good dispersibility of the inorganic layered compound and can form a uniform film in close contact with the photosensitive layer. Any insoluble polymer can be appropriately selected and used. Specifically, for example, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, partially saponified polyvinyl acetate, ethylene-vinyl alcohol copolymer, water-soluble cellulose derivative, gelatin, starch derivative, Arabic Examples include water-soluble polymers such as rubber, and water-insoluble polymers such as polyvinylidene chloride, poly (meth) acrylonitrile, polysulfone, polyvinyl chloride, polyethylene, polycarbonate, polystyrene, polyamide, and cellophane. These may be used in combination of two or more as required. Of these, water-soluble polymers are preferred from the viewpoint of easy removal of the protective layer remaining in the non-image area and handling properties during film formation, water-soluble acrylic resins such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyacrylic acid, Gelatin, gum arabic, and the like are preferable. Among them, polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, gum arabic are preferable from the viewpoint that they can be applied using water as a solvent and can be easily removed by dampening water during printing. Etc. are more preferable.

  The polyvinyl alcohol that can be used in the protective layer according to the present invention may be partially substituted with an ester, an ether, and an acetal as long as it contains a substantial amount of an unsubstituted vinyl alcohol unit having the necessary water solubility. Similarly, a part may contain other copolymerization components. Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a polymerization degree of 300 to 2400. Specifically, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, manufactured by Kuraray Co., Ltd. PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8, and the like. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal, polyvinyl acetal, and copolymers thereof.

Next, an example of a general dispersion method of the inorganic layered compound used for the protective layer will be described. First, 5 to 10 parts by weight of the swellable layered compound mentioned above as a preferred inorganic layered compound is added to 100 parts by weight of water, and the mixture is swelled and swollen.
Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. A dispersion of 5 to 10% by weight of the inorganic stratiform compound dispersed by the above method is highly viscous or gelled and has very good storage stability. When preparing a protective layer coating solution using this dispersion, it is preferably prepared by diluting with water and stirring sufficiently, and then blending with a binder solution.

Known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film can be added to the protective layer coating solution. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer can also be added. Furthermore, known additives for improving the adhesion to the photosensitive layer and the temporal stability of the coating solution may be added to the coating solution. The protective layer coating solution thus prepared is applied onto the photosensitive layer provided on the support and dried to form a protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The protective layer is coated on the photosensitive layer by a known coating method such as a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, a spray coating method, a dip coating method, or a bar coating method. The protective layer coating amount, the coating amount after drying is preferably in the range of 0.5 to 10 g / m ^2, more preferably in the range of 1 to 5 g / m ^2.

In the present invention, an intermediate layer made of a water-soluble polymer for controlling adhesion and removability can be further provided between the photosensitive layer and the protective layer. The dry coating weight of this intermediate layer is usually 0.1 to 10 g / m ² , preferably 0.1 to 2.0 g / m ² .

  The coating method of the protective layer according to the present invention and the intermediate layer provided as desired is not particularly limited, and is a method described in US Pat. No. 3,458,311 or JP-A-55-49729. Can be applied. Moreover, water is used as a solvent for application.

  The protective layer according to the present invention has moderate cracks so that the edges do not become soiled by cutting, has good adhesiveness with the photosensitive layer, has excellent oxygen barrier properties, and It is transparent to actinic rays for writing on the photosensitive layer, that is, has a characteristic that does not hinder the writing function.

<Photosensitive layer>
Next, the photosensitive layer according to the present invention will be described. The photosensitive layer of the lithographic printing plate precursor according to the invention preferably contains an infrared absorber, a polymerization initiator, a polymerizable compound, and a binder polymer, but is not limited thereto. Furthermore, a coloring agent and other arbitrary components can be included as needed. Furthermore, although it is desirable that it is a polymerizable negative photosensitive layer, it is not limited to this.

  Since the polymerizable negative photosensitive layer in the present invention is sensitive to infrared light, it can be exposed to an infrared laser useful for CTP. The infrared absorber contained therein is in an electronically excited state with high sensitivity to infrared laser irradiation (exposure), and the electron transfer, energy transfer, heat generation (photothermal conversion function), etc. in the electronically excited state are contained in the photosensitive layer. It acts on the polymerization initiators coexisting with each other to cause a chemical change in the polymerization initiators to generate radicals.

  The lithographic printing plate precursor according to the invention is particularly suitable for plate making directly drawn with an infrared laser beam having a wavelength of 750 to 1400 nm because the photosensitive layer contains an infrared absorber, and the conventional lithographic printing plate precursor Compared to the above, high image forming properties can be exhibited.

Below, each component which comprises the photosensitive layer concerning this invention is demonstrated.
[(I) Infrared absorber]
The photosensitive layer according to the present invention contains an infrared absorber for the purpose of developing an energy transfer function (electron transfer), a photothermal conversion function, and the like.
Infrared absorbers are in an electronically excited state with high sensitivity to infrared laser irradiation (exposure), and the electron transfer, energy transfer, heat generation (photothermal conversion function), etc. related to the electron excited state act on the polymerization initiator described later. Thus, it is useful for generating a radical by causing a chemical change in the polymerization initiator with high sensitivity.
The infrared absorbent used in the present invention is preferably a dye or pigment having an absorption maximum at a wavelength of 750 nm to 1400 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.

  Examples of preferable dyes include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, 58-181690, JP-A-58-194595, etc., methine dyes, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59- No. 73996, JP-A-60-52940, JP-A-60-63744 and the like, Naphthoquinone dyes described in JP-A-58-112792, etc., British Patent 434,875 And cyanine dyes.

  Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. . Moreover, as another example preferable as a dye, the near-infrared absorptive dye described as the formula (I) and (II) in US Patent 4,756,993 can be mentioned.

  Other preferable examples of the infrared absorbing dye in 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 particularly preferred examples include cyanine dyes represented by the following general formula (a).

In formula (a), 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. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se. Xa ^- the Za described later ^- is defined as for, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photosensitive 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 (a) has an anionic substituent in its structure and neutralization of charge is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of storage stability of the photosensitive layer coating solution. Fluorophosphate ions and aryl sulfonate ions.

Specific examples of the cyanine dye represented by formula (a) that can be suitably used in the present invention include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. Can do.
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 size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Within this preferred particle size range, excellent dispersion stability of the pigment in the photosensitive layer can be obtained, and a uniform photosensitive 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).

When these infrared absorbers are used in the photosensitive layer according to the present invention, they may be added to the same layer as other components, or another layer may be provided and added thereto.
From the viewpoint of uniformity in the photosensitive layer and durability of the photosensitive layer, these infrared absorbers are 0.01 to 50% by mass, preferably 0.1 to 10% by mass, based on the total solid content constituting the photosensitive layer. In the case of a dye, particularly preferably 0.5 to 10% by mass, and in the case of a pigment, 0.1 to 10% by mass can be particularly preferably added.

[(B) polymerization initiator]
Examples of the polymerization initiator used in the present invention include onium salts, active halogen compounds, oxime ester compounds, and borate compounds. These may use only 1 type and may use 2 or more types together. In the present invention, an onium salt is preferable as a polymerization initiator, and a sulfonium salt is particularly preferable.
Examples of the sulfonium salt polymerization initiator suitably used in the present invention include onium salts represented by the following general formula (1).

In the general formula (1), R ¹¹ , R ¹² and R ¹³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferable substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. (Z ¹¹ ) ⁻ represents a counter ion selected from the group consisting of halogen ion, perchlorate ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, and sulfonate ion, preferably perchloric acid Ions, hexafluorophosphate ions, carboxylate ions, and aryl sulfonate ions.

  Specific examples ([OS-1] to [OS-12]) of the onium salt represented by the general formula (1) are shown below, but are not limited thereto.

In addition to the above, specific aromatic sulfonium salts described in JP-A Nos. 2002-148790, 2002-148790, 2002-350207, and 2002-6482 are also preferably used.
In the present invention, in addition to the sulfonium salt polymerization initiator, other polymerization initiators (other radical generators) can be used. Other radical generators include onium salts other than sulfonium salts, triazine compounds having a trihalomethyl group, peroxides, azo polymerization initiators, azide compounds, quinonediazides, active halogen compounds, oxime ester compounds, triaryls. Examples thereof include monoalkyl borate compounds. Among them, onium salts are preferable because of their high sensitivity. Moreover, these polymerization initiators (radical generators) can be used in combination with the sulfonium salt polymerization initiator as an essential component.

Other onium salts that can be suitably used in the present invention include iodonium salts and diazonium salts. In the present invention, these onium salts function not as acid generators but as radical polymerization initiators.
Other onium salts in the present invention include onium salts represented by the following general formulas (2) and (3).

In the general formula (2), Ar ²¹ and Ar ²² each independently represent an aryl group having 20 or less carbon atoms which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a carbon atom having 12 or less carbon atoms. An aryloxy group is mentioned. (Z ²¹ ) ⁻ represents a counter ion having the same meaning as (Z ¹¹ ) ⁻ .

In the general formula (3), Ar ³¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. (Z ³¹ ) ⁻ represents a counter ion having the same meaning as (Z ¹¹ ) ⁻ .

  In the present invention, the onium salts represented by the general formula (2) ([OI-1] to [OI-10]) and the onium salt represented by the general formula (3) ([ Specific examples of ON-1] to [ON-5] are given below, but are not limited thereto.

  Specific examples of onium salts that can be suitably used as a polymerization initiator (radical generator) in the present invention include those described in JP-A No. 2001-133696.

  The polymerization initiator (radical generator) used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing plate precursor can be handled under white light.

  In the present invention, the total content of the polymerization initiator is from 0.1 to 50% by mass, preferably from 0. It is 5-30 mass%, Most preferably, it is 1-20 mass%.

As a polymerization initiator in this invention, only 1 type may be used and 2 or more types may be used together. When two or more polymerization initiators are used in combination, for example, a plurality of suitably used sulfonium salt polymerization initiators may be used, or a sulfonium salt polymerization initiator and another polymerization initiator may be used in combination. Also good.
When the sulfonium salt polymerization initiator and another polymerization initiator are used in combination, the content ratio (mass ratio) is preferably 100/1 to 100/50, more preferably 100/5 to 100/25.

Moreover, a polymerization initiator may be added to the same layer as other components, or another layer may be provided and added thereto.
When a highly sensitive sulfonium salt polymerization initiator, which is preferable as a polymerization initiator, is used for the photosensitive layer in the present invention, the radical polymerization reaction proceeds effectively, and the strength of the formed image portion becomes very high. Therefore, combined with the high oxygen blocking function of the protective layer described later, a lithographic printing plate having high image area strength can be produced, and as a result, printing durability is further improved. In addition, since the sulfonium salt polymerization initiator itself is excellent in stability over time, even when the produced lithographic printing plate precursor is stored, the occurrence of an undesirable polymerization reaction is effectively suppressed. Will also have.

[(C) Polymerizable compound]
The polymerizable compound used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one, preferably two or more ethylenically unsaturated bonds. 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, that is, 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.

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

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.
Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. Those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-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 compound containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula to a polyisocyanate compound having two or more isocyanate groups. Can be mentioned.

^{_{CH 2 = C (R a)}} COOCH 2 CH (R b) OH ··· formula (wherein, R ^a and R ^b 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. Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238, It is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. Further, 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 can also 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 combined use, and addition amount can be arbitrarily set according to the final performance design. For example, it is selected from the following viewpoints. From the viewpoint of photosensitive speed, a structure having a high 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 furthermore, different functional numbers and different polymerizable groups (for example, acrylic ester, methacrylic ester, styrenic compound, A method of adjusting both photosensitivity and strength by using a vinyl ether compound) is also effective. A compound having a large molecular weight or a compound having high hydrophobicity is excellent in photosensitive speed and film strength, but is not preferable in terms of development speed and precipitation in a developer. In addition, the selection and use method of the addition polymerization compound is also an important factor for compatibility and dispersibility with other components in the photosensitive layer composition (for example, binder polymer, initiator, colorant, etc.). For example, the compatibility may be improved by using a low-purity compound or using two or more kinds in combination.
In the lithographic printing plate precursor according to the invention, a specific structure may be selected for the purpose of improving adhesion to a support or a protective layer described later.

  Regarding the content of the addition polymerizable compound in the photosensitive layer composition, the solid content in the photosensitive layer composition is considered from the viewpoints of sensitivity, occurrence of phase separation, adhesiveness of the photosensitive layer, and precipitation from the developer. The amount is preferably 5 to 80% by mass, more preferably 40 to 75% by mass.

  These may be used alone or in combination of two or more. In addition, as for the method of using the addition polymerizable compound, an appropriate structure, blending, and addition amount can be arbitrarily selected from the viewpoints of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface tackiness, and the like. Furthermore, in the lithographic printing plate precursor according to the invention, a layer constitution / coating method such as undercoating or overcoating can be carried out.

[(D) Binder polymer]
The binder polymer used in the present invention is contained from the viewpoint of improving the film property, and various types can be used as long as it has a function of improving the film property. Especially, as a binder polymer suitable in this invention, it is a binder polymer which has a repeating unit represented by the following general formula (i). Hereinafter, the binder polymer having the repeating unit represented by the general formula (i) is appropriately referred to as a specific binder polymer and will be described in detail.

(In General Formula (i), R ¹ represents a hydrogen atom or a methyl group, and R ² contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And a linking group having a total number of atoms of 2 to 82. A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. N represents an integer of 1 to 5.)

First, R ¹ in the general formula (i) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.
The linking group represented by R ² in the general formula (i) includes two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. The number is 2 to 82, preferably 2 to 50, and more preferably 2 to 30. The total number of atoms shown here refers to the number of atoms including the substituent when the linking group has a substituent. More specifically, the number of atoms constituting the main skeleton of the linking group represented by R ² is preferably 1-30, more preferably 3-25, and 4-20. More preferred is 5-10. The “main skeleton of the linking group” in the present invention refers to an atom or an atomic group used only for linking A and the terminal COOH in the general formula (i), and particularly when there are a plurality of linking paths. Refers to an atom or atomic group that constitutes a path with the least number of atoms used. Therefore, when a linking group has a ring structure, the number of atoms to be included differs depending on the linking site (for example, o-, m-, p-, etc.).

More specific examples include alkylene, substituted alkylene, arylene, substituted arylene, and the like, and a structure in which a plurality of these divalent groups are linked by an amide bond or an ester bond may be used.
Examples of the linking group having a chain structure include ethylene and propylene. A structure in which these alkylenes are linked via an ester bond can also be exemplified as a preferable example.

Among these, the linking group represented by R ² in the general formula (i) is preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. More specifically, a compound having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, dicyclohexyl, tercyclohexyl, norbornane and the like, which may be substituted by one or more arbitrary substituents And (n + 1) valent hydrocarbon groups by removing (n + 1) hydrogen atoms on an arbitrary carbon atom constituting. R ² preferably has 3 to 30 carbon atoms including a substituent.

One or more arbitrary carbon atoms of the compound constituting the aliphatic cyclic structure may be replaced with a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. In terms of printing durability, R ² represents a condensed polycyclic aliphatic hydrocarbon, a bridged cyclic aliphatic hydrocarbon, a spiro aliphatic hydrocarbon, an aliphatic hydrocarbon ring assembly (a plurality of rings are connected by a bond or a linking group). A (n + 1) valent hydrocarbon group having an aliphatic cyclic structure which may have a substituent of 5 to 30 carbon atoms containing two or more rings. . Also in this case, the carbon number includes the carbon atom of the substituent.

As the linking group represented by R ² , those having 5 to 10 atoms constituting the main skeleton of the linking group are particularly preferred, and are structurally a chain structure, and an ester bond in the structure. And those having a cyclic structure as described above are preferred.
Examples of the substituent that can be introduced into the linking group represented by R ² include monovalent nonmetallic atomic groups other than hydrogen, such as halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups. Group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N- Diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy , Arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-aryl Ureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N ′ -Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N ' -Aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-al Kill-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group,

Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, Alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and the like Conjugated base group, N-alkylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonylsulfamoyl group (—SO ₂ NHSO ₂ (aryl)) and its conjugate base Group, N-alkylsulfonylcarbamoyl group (—CONHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ) _3), aryloxy silyl group (-Si (Oaryl) _3), hydroxy Lil group (-Si (OH) ₃₎ and its conjugated base group, a phosphono group (-PO ₃ H ₂₎ and its conjugated base group, a dialkyl phosphono group _{(-PO 3 (alkyl) 2)} , diaryl phosphono group ( -PO ₃ (aryl) _2), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )), monoalkyl phosphono group (-PO ₃ H (alkyl)) and its conjugated base group, monoarylphosphono Group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy Group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkylphosphonooxy group ( -OPO ₃ H (alkyl)) and its conjugated base group, monoarylphosphono group (-OPO ₃ H (aryl)) and its conjugated base group, a cyano group, a nitro group, a dialkyl boryl group (-B (alkyl) ₂ ), diarylboryl group (-B (aryl) ₂ ), alkylarylboryl group (-B (alkyl) (aryl)), dihydroxyboryl group (-B (OH) ₂ ) and its conjugate base group, alkylhydroxyboryl And a group (—B (alkyl) (OH)) and its conjugate base group, an arylhydroxyboryl group (—B (aryl) (OH)) and its conjugate base group, an aryl group, an alkenyl group and an alkynyl group.

  In the lithographic printing plate precursor according to the invention, although depending on the design of the photosensitive layer, a substituent having a hydrogen atom capable of hydrogen bonding, particularly a substituent having an acid dissociation constant (pKa) smaller than that of a carboxylic acid is , Because it tends to lower the printing durability. On the other hand, hydrophobic substituents such as halogen atoms, hydrocarbon groups (alkyl groups, aryl groups, alkenyl groups, alkynyl groups), alkoxy groups, aryloxy groups and the like are more preferable because they tend to improve printing durability. When the cyclic structure is a monocyclic aliphatic hydrocarbon having 6 or less members such as cyclopentane or cyclohexane, it preferably has such a hydrophobic substituent. If possible, these substituents may be bonded to each other or with a substituted hydrocarbon group to form a ring, and the substituent may be further substituted.

R ³ in the case where A in formula (i) is NR ³ — represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.

  Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, isobutyl group, sec-butyl group, 1 carbon number such as tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group Up to 10 linear, branched or cyclic alkyl groups.

Specific examples of the aryl group include carbon having one heteroatom selected from the group consisting of an aryl group having 1 to 10 carbon atoms such as a phenyl group, a naphthyl group, and an indenyl group, a nitrogen atom, an oxygen atom, and a sulfur atom. Examples include heteroaryl groups of 1 to 10, such as furyl, thienyl, pyrrolyl, pyridyl, and quinolyl groups.
Specific examples of the alkenyl group include those having 1 to 10 carbon atoms such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group and the like. A linear, branched, or cyclic alkenyl group is mentioned.

Specific examples of the alkynyl group include alkynyl groups having 1 to 10 carbon atoms such as ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group. The substituent that R ³ may have is the same as those exemplified as the substituent that R ² can introduce. However, the carbon number of R < ³ > is 1-10 including the carbon number of a substituent.
A in the general formula (i) is preferably an oxygen atom or —NH— because synthesis is easy.

N in the general formula (i) represents an integer of 1 to 5, and is preferably 1 in terms of printing durability.
Although the preferable specific example of the repeating unit represented by general formula (i) below is shown, this invention is not limited to these.

  One type of repeating unit represented by the general formula (i) may be contained in the binder polymer, or two or more types may be contained. The specific binder polymer in the present invention may be a polymer composed only of the repeating unit represented by the general formula (i), but is usually used as a copolymer in combination with other copolymerization components. The total content of the repeating unit represented by the general formula (i) in the copolymer is appropriately determined depending on its structure, the design of the photosensitive layer composition, etc. It is contained in the range of mol%, more preferably 5 to 40 mol%, still more preferably 5 to 20 mol%.

  As a copolymerization component in the case of using as a copolymer, a conventionally well-known thing can be used without a restriction | limiting, if it is a monomer which can be radically polymerized. Specific examples include monomers described in “Polymer Data Handbook—Basic Edition” (Edition of Polymer Society, Bafukan, 1986). One type of such copolymerization component may be used, or two or more types may be used in combination.

  The molecular weight of the specific binder polymer in the present invention is appropriately determined from the viewpoint of image formability and printing durability. The molecular weight is preferably in the range of 2,000 to 1,000,000, more preferably 5,000 to 500,000, and still more preferably 10,000 to 200,000.

  The binder polymer used in the present invention may be a specific binder polymer alone, or may be used as a mixture by combining one or more other binder polymers. The binder polymer used in combination is used in the range of 1 to 80% by mass, preferably 1 to 40% by mass, and more preferably 1 to 20% by mass with respect to the total mass of the binder polymer component. As the binder polymer that can be used in combination, a conventionally known binder polymer can be used without limitation, and specifically, an acrylic main chain binder, a urethane binder, or the like often used in the industry is preferably used. Furthermore, those having a polymerizable group often used in the industry are preferred, and those having an acidic group are preferred.

Although the total amount of the specific binder polymer in the photosensitive layer composition and the binder polymer that may be used in combination can be determined as appropriate, it is usually 10 to 90 with respect to the total mass of nonvolatile components in the photosensitive layer composition. It is mass%, Preferably it is 20-80 mass%, More preferably, it is the range of 30-70 mass%.
Moreover, as an acid value (meg / g) of such a binder polymer, it is preferable that it is the range of 2.00-3.60.

-Other binder polymers that can be used together-
The other binder polymer that can be used in combination with the specific binder polymer is preferably a binder polymer having a radical polymerizable group.
The radical polymerizable group is not particularly limited as long as it can be polymerized by radicals, but α-substituted methylacrylic group [—OC (═O) —C (—CH ₂ Z) ═CH ₂ , Z = A hydrocarbon group starting from a hetero atom], an acryl group, a methacryl group, an allyl group, and a styryl group. Among these, an acryl group and a methacryl group are preferable.

  The content of the radical polymerizable group in the binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 1 g per binder polymer from the viewpoint of sensitivity and storage stability. It is 10.0 mmol, More preferably, it is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol.

Further, the other binder polymer that can be used in combination is preferably one having an alkali-soluble group. The content of alkali-soluble groups in the binder polymer (acid value by neutralization titration) is preferably from 0.1 to 3.0 mmol, more preferably from 1 to 3.0 g of binder polymer, from the viewpoints of precipitation of developing residue and printing durability. Is 0.2 to 2.0 mmol, most preferably 0.45 to 1.0 mmol.
The mass average molecular weight of such a binder polymer is preferably from 2,000 to 1,000,000, more preferably from 10,000 to 300, from the viewpoints of film properties (press life) and solubility in a coating solvent. In the range of 20,000 to 200,000.

Further, the glass transition point (Tg) of such a binder polymer is preferably 70 to 300 ° C., more preferably 80 to 250 ° C., and most preferably 90 to 90 ° C. from the viewpoints of storage stability, printing durability, and sensitivity. It is in the range of 200 ° C.
As a means for increasing the glass transition point of the binder polymer, the molecule preferably contains an amide group or an imide group, and particularly preferably contains a methacrylamide or a methacrylamide derivative.

(Other ingredients)
In addition to the above basic components, the photosensitive layer according to the present invention may further contain other components suitable for its use and production method. Hereinafter, preferred additives will be exemplified.

-Colorant-
A dye or a pigment may be added to the photosensitive layer according to the present invention for the purpose of coloring. As a result, it is possible to improve the so-called plate inspection properties such as the visibility of the image after plate making as a printing plate and the suitability of an image density measuring machine. Specific examples of the colorant include pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes, cyanine dyes, and the like. Among them, a cationic dye is preferable.
The addition amount of the dye and pigment as the colorant is preferably about 0.5% by mass to about 5% by mass with respect to the non-volatile components in the total photosensitive layer composition.

-Polymerization inhibitor-
In the photosensitive layer according to the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the polymerizable compound having an ethylenically unsaturated double bond, that is, the polymerizable compound. . Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the nonvolatile component in the photosensitive layer composition. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide or the like may be added to prevent polymerization inhibition by oxygen and may be unevenly distributed on the surface of the layer in the course of drying after coating. The addition amount of the higher fatty acid derivative is preferably about 0.5% by mass to about 10% by mass with respect to the nonvolatile components in the photosensitive layer composition.

-Other additives-
Furthermore, the photosensitive layer according to the present invention may be added with known additions such as inorganic fillers for improving the physical properties of the cured film, other plasticizers, and oil-sensitizing agents that can improve the ink deposition on the surface of the photosensitive layer. An agent may be added. Examples of plasticizers include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin, and addition polymerization with binder polymer. Generally, it can be added in a range of 10% by mass or less based on the total mass with the compound.
In addition, in the photosensitive layer according to the present invention, in order to enhance the effect of heating / exposure after development for the purpose of improving the film strength (printing durability) described later, a UV initiator, a thermal crosslinking agent, etc. are added. Can also be done.

[Support]
As the support in the present invention, a support subjected to a hydrophilization treatment as described later is used. Examples of such a support include paper, polyester film, and aluminum plate. Among them, a surface having good dimensional stability, relatively inexpensive, and having excellent hydrophilicity and strength by surface treatment as required. An aluminum plate that can be provided is more preferred. A composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 is also preferable.

  The aluminum plate as the most preferable support in the present invention is a metal plate mainly composed of dimensionally stable aluminum, and contains pure aluminum plate, aluminum as a main component, and a trace amount of foreign elements. An alloy plate or aluminum (alloy) is selected from a laminated or vapor-deposited plastic film or paper. In the following description, the above-mentioned support made of aluminum or an aluminum alloy is generically used as an aluminum support. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is 10% by mass or less. In the present invention, a pure aluminum plate is suitable. However, since pure aluminum is difficult to manufacture in terms of refining technology, it may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and conventionally known and used materials such as JIS A 1050, JIS A 1100, JIS A 3103, JIS A 3005, etc. Can be used as appropriate.

Moreover, the thickness of the aluminum support body used for this invention is about 0.1 mm-about 0.6 mm. This thickness can be changed as appropriate according to the size of the printing press, the size of the printing plate, and the desire of the user.
Such an aluminum support is subjected to a surface treatment described later to be hydrophilized.

(Roughening treatment)
Examples of the roughening treatment method include mechanical roughening, chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, the electrochemical surface roughening method in which the surface is electrochemically roughened in hydrochloric acid or nitric acid electrolyte solution, the aluminum surface is scratched with a metal wire, the wire brush grain method, the surface of the aluminum is polished with a polishing ball and an abrasive. A mechanical graining method such as a pole grain method, a brush grain method in which the surface is roughened with a nylon brush and an abrasive, can be used, and the above roughening methods can be used alone or in combination. Among them, a method usefully used for roughening is an electrochemical method in which roughening is performed chemically in hydrochloric acid or nitric acid electrolyte, and a suitable amount of electricity at the time of anode is 50 C / dm ^{2 to} 400 C / dm ² . It is a range. More specifically, in the electrolytic solution containing from 0.1 to 50% hydrochloric acid or nitric acid, the temperature 20 to 80 ° C., for 1 second to 30 minutes, alternating at a current density of 100C / dm ² ~400C / dm ² It is preferable to perform direct current electrolysis.

  The roughened aluminum support may be chemically etched with acid or alkali. Etching agents suitably used are caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like, and preferred ranges of concentration and temperature are 1 to 50% and 20%, respectively. ~ 100 ° C. Pickling is performed to remove dirt (smut) remaining on the surface after etching. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borohydrofluoric acid and the like are used. In particular, as a method for removing smut after the electrochemical surface roughening treatment, contact with 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 is preferable. And the alkali etching method described in Japanese Patent Publication No. 48-28123. After the treatment as described above, the method and conditions are not particularly limited as long as the surface roughness Ra of the treated surface is about 0.2 to 0.5 μm.

(Anodizing treatment)
The aluminum support that has been treated as described above to form an oxide layer is then anodized.
In the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, or an aqueous solution of boric acid / sodium borate is used alone or in combination as a main component of the electrolytic bath. In this case, the electrolyte solution may of course contain at least components normally contained in at least an Al alloy plate, an electrode, tap water, groundwater and the like. Further, the second and third components may be added. Here, the second and third components are, for example, metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and ammonium ions. Examples include cations, nitrate ions, carbonate ions, chloride ions, phosphate ions, fluorine ions, sulfite ions, titanate ions, silicate ions, borate ions and the like, and the concentration is 0 to 10,000 ppm. May be included. There are no particular limitations on the conditions of the anodizing treatment, but the treatment is preferably carried out by direct current or alternating current electrolysis at a current density of 0.1 to 40 A / m ² at 30 to 500 g / liter, a treatment liquid temperature of 10 to 70 ° C. . The thickness of the formed anodic oxide film is in the range of 0.5 to 1.5 μm. Preferably it is the range of 0.5-1.0 micrometer. The support prepared by the above treatment is treated so that the pore diameter of the micropores existing in the anodized film is in the range of 5 to 10 nm and the pore density is in the range of 8 × 10 ¹⁵ to 2 × 10 ¹⁶ pieces / m ^2. It is preferred that the conditions are selected.

A widely known method can be applied as the hydrophilic treatment on the surface of the support. As a particularly preferable treatment, a hydrophilic treatment with silicate or polyvinylphosphonic acid is performed. A film | membrane is formed by 2-40 mg / m < ² > as Si or P element amount, More preferably, it is 4-30 mg / m < ² >. The coating amount can be measured by fluorescent X-ray analysis.

  The hydrophilization treatment is carried out by applying an anodized film to an aqueous solution containing 1 to 30% by mass, preferably 2 to 15% by mass of alkali metal silicate or polyvinylphosphonic acid, and having a pH of 10 to 13 at 25 ° C. This is carried out by immersing the aluminum support on which is formed, for example, at 15 to 80 ° C. for 0.5 to 120 seconds.

  As the alkali metal silicate used for the hydrophilization treatment, sodium silicate, potassium silicate, lithium silicate, or the like is used. Examples of the hydroxide used for increasing the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or a group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble substances such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Salt. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, potassium titanium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, etc. Can be mentioned.

  Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5.0% by mass. Silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective. Surface obtained by combining a support with electrolytic grains as disclosed in JP-B-46-27481, JP-A-52-58602, JP-A-52-30503, and the above anodizing treatment and hydrophilization treatment Processing is also useful.

[Preparation of lithographic printing plate precursor]
In the lithographic printing plate precursor according to the invention, a photosensitive layer and a protective layer are provided on a support in this order, and further an undercoat layer and the like are provided as necessary. Such a lithographic printing plate precursor can be produced by dissolving the above-described coating liquids containing the various components in an appropriate solvent and sequentially coating them on a support.

When coating the photosensitive layer, the photosensitive layer components are dissolved in various organic solvents to form a photosensitive layer coating solution, which is applied onto the support or the undercoat layer.
Solvents used here include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, lactic acid There are ethyl and the like. These solvents can be used alone or in combination. The solid content in the photosensitive layer coating solution is suitably 2 to 50% by mass.

The coating amount of the photosensitive layer mainly affects the sensitivity of the photosensitive layer, the developability, and the strength and printing durability of the exposed film, and is preferably selected as appropriate according to the application. When the coating amount is too small, the printing durability is not sufficient. On the other hand, if the amount is too large, the sensitivity is lowered, it takes time for exposure, and a longer time is required for development processing, which is not preferable. For the lithographic printing plate precursor for scanning exposure, the coating amount is suitably in the range of about 0.1 g / m ² to about 10 g / m ² in terms of the mass after drying. More preferably from 0.5 to 5 g / m ^2.

[Intermediate layer (undercoat layer)]
In the lithographic printing plate precursor according to the invention, an intermediate layer (undercoat layer) may be provided for the purpose of improving the adhesion and soiling between the photosensitive layer and the support. Specific examples of such an intermediate layer include JP-B-50-7481, JP-A-54-72104, JP-A-59-101651, JP-A-60-149491, JP-A-60-232998, JP-A-3-56177, JP-A-4-282737, JP-A-5-16558, JP-A-5-246171, JP-A-7-159983, JP-A-7-314937, JP-A-8-202025, Special Kaihei 8-320551, JP 9-34104, JP 9-236911, JP 9-269593, JP 10-69092, JP 10-115931, JP 10-161317, JP 10-260536, JP-A-10-282682, JP-A-11-84684, JP-A-10-69092, JP-A-10-115931, Kaihei 11-38635, JP-A-11-38629, JP-A-10-282645, JP-A-10-301262, JP-A-11-24277, JP-A-11-109641, JP-A-10-319600, JP-A-10-319600 11-84684, JP-A-11-327152, JP-A-2000-10292, JP-A-2000-235254, JP-A-2000-352854, JP-A-2001-209170, Japanese Patent Application No. 11-284091, etc. Can be mentioned.

<Plate making method>
Hereinafter, the plate making method of the planographic printing plate of the present invention will be described.
The plate making method of the lithographic printing plate of the present invention comprises the step of setting a laminate comprising a plurality of the above-described lithographic printing plate precursors of the present invention in direct contact with the protective layer and the back surface of the aluminum support in a plate setter. Then, after the lithographic printing plate precursor is automatically conveyed one by one, after being exposed at a wavelength of 750 nm to 1400 nm, the conveyance speed is 1.25 m / min or more without substantially undergoing heat treatment. Development processing is performed.

Even if the lithographic printing plate precursor of the present invention described above is laminated without interposing the interleaf, the adhesion between the lithographic printing plate precursors and the generation of scratches on the protective layer are suppressed. It can be applied to such a plate making method.
According to the lithographic printing plate making method of the present invention, since a laminate in which lithographic printing plate precursors are laminated without interposing the interleaving paper is used, it is not necessary to remove the interleaving paper.

  Needless to say, this plate making method is also suitable for plate making of the above-described lithographic printing plate precursor according to the present invention, but contains at least an infrared absorber, a polymerization initiator, and a polymerizable compound, and is 750 nm to 1400 nm. The present invention can be suitably applied to any lithographic printing plate precursor provided with a polymerizable negative photosensitive layer whose solubility in an alkaline developer is reduced by exposure at a wavelength of. Specifically, it may be a photosensitive layer containing each component of “infrared absorber, polymerization initiator, and polymerizable compound” described in the column of each component constituting the photosensitive layer of the lithographic printing plate precursor according to the invention. What is necessary is just to include a well-known thing as a binder polymer, and does not need to contain it.

  The photosensitive layer to which the lithographic printing plate making method of the present invention is applied has a development rate of 80 nm / sec or more in an unexposed portion with respect to an alkaline developer having a pH of 10 to 13.5, and exposure of the alkaline developer. It is preferable that the penetration rate in the part has a physical property of 50 nF / sec or less. The method for measuring the developing speed of the unexposed portion of the photosensitive layer and the penetration speed of the alkali developer into the cured photosensitive layer is the same as the method described in Japanese Patent Application No. 2004-248535 previously filed by the present applicant. Can be used. Control of the developing speed of the unexposed part of the photosensitive layer and the penetration speed of the alkali developer into the cured photosensitive layer can be performed by a conventional method, but as a typical method, a method using the specific binder polymer In addition, the addition of a hydrophilic compound is useful for improving the developing speed of the unexposed area, and the means for adding a hydrophobic compound is useful for suppressing the penetration of the developer into the exposed area.

〔exposure〕
The light source used for the exposure treatment in the present invention may be any light source as long as it can be exposed at a wavelength of 750 nm to 1400 nm, and an infrared laser is preferable. Especially, in this invention, it is preferable to image-expose with the solid laser and semiconductor laser which radiate | emit infrared rays with a wavelength of 750 nm-1400 nm. The laser output is preferably 100 mW or more, and a multi-beam laser device is preferably used to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec. The energy applied to the planographic printing plate precursor is preferably 10 to 300 mJ / cm ² . If the exposure energy is too low, the photosensitive layer is not sufficiently cured. If the exposure energy is too high, the photosensitive layer may be laser ablated and the image may be damaged.

  In the exposure processing in the present invention, exposure can be performed by overlapping light beams of light sources. Overlap means that the sub-scanning pitch width is smaller than the beam diameter. The overlap can be expressed quantitatively by FWHM / sub-scanning pitch width (overlap coefficient), for example, when the beam diameter is expressed by the half width (FWHM) of the beam intensity. In the present invention, the overlap coefficient is preferably 0.1 or more.

  The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylindrical outer surface scanning method, a cylindrical inner surface scanning method, a planar scanning method, or the like can be used. The channel of the light source may be a single channel or a multi-channel, but in the case of a cylindrical outer surface system, a multi-channel is preferably used.

  In the present invention, as described above, the exposed lithographic printing plate precursor is subjected to a development process without performing any special heat treatment and water washing treatment. By not performing this heat treatment, image non-uniformity due to the heat treatment can be suppressed. Further, by performing neither heat treatment nor water washing treatment, stable high-speed processing is possible in development processing.

〔developing〕
In the development processing in the present invention, a non-image portion of the photosensitive layer is removed using a developer.
In the present invention, as described above, the processing speed in the development process, that is, the transport speed (line speed) of the lithographic printing plate precursor in the development process needs to be 1.25 m / min or more. Preferably, it is 1.35 m / min or more. Moreover, there is no restriction | limiting in particular in the upper limit of a conveyance speed, However, From a viewpoint of the stability of conveyance, it is preferable that it is 3 m / min or less.
Hereinafter, the developer used in the present invention will be described.

(Developer)
The developer used in the present invention is preferably an alkaline aqueous solution having a pH of 14 or less, and preferably contains an aromatic anionic surfactant.

(Aromatic anionic surfactant)
The aromatic anionic surfactant used in the developer in the present invention has a development accelerating effect and a dispersion stabilizing effect in the developer of the polymerizable negative photosensitive layer component and the protective layer component. preferable. Among these, the aromatic anionic surfactant used in the present invention is preferably a compound represented by the following general formula (A) or general formula (B).

In the above general formula (A) or general formula (B), R ¹ and R ³ each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, specifically an ethylene group. , Propylene group, butylene group, pentylene group, and the like, among which ethylene group and propylene group are particularly preferable.
m and n each independently represent an integer selected from 1 to 100. Among them, 1 to 30 are preferable, and 2 to 20 are more preferable. When m is 2 or more, a plurality of R ¹ may be the same or different. Similarly, when n is 2 or more, a plurality of R ³ may be the same or different.
t and u each independently represents 0 or 1.

R ² and R ⁴ each independently represent a linear or branched alkyl group having 1 to 20 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, hexyl group, dodecyl group Among them, a methyl group, an ethyl group, an iso-propyl group, an n-propyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group are particularly preferable.
p and q each represent an integer selected from 0 to 2; Y ¹ and Y ² each represent a single bond or an alkylene group having 1 to 10 carbon atoms. Specifically, a single bond, a methylene group or an ethylene group is preferred, and a single bond is particularly preferred.
(Z ¹ ) ^{r +} and (Z ² ) ^{s +} each independently represents an alkali metal ion, an alkaline earth metal ion, or an ammonium ion that is unsubstituted or substituted with an alkyl group. Sodium ion, potassium ion, magnesium ion, calcium ion, ammonium ion, secondary to quaternary ammonium ion substituted with an alkyl group, aryl group, or aralkyl group in the range of 1 to 20 carbon atoms, etc. In particular, sodium ion is preferable. r and s each represent 1 or 2.
Specific examples are shown below, but the present invention is not limited thereto.

  These aromatic anionic surfactants may be used alone or in appropriate combination of two or more. The amount of the aromatic anionic surfactant added is preferably such that the concentration of the aromatic anionic surfactant in the developer is in the range of 1.0 to 10% by mass, more preferably in the range of 2 to 10% by mass. It is effective to do. Here, if the content is 1.0% by mass or less, the developability and the solubility of the photosensitive layer components are lowered, and if the content is 10% by mass or more, the printing durability of the printing plate is reduced. .

In addition to the aromatic anionic surfactant, other surfactants may be used in combination with the developer according to the present invention. Examples of other surfactants include polyoxyethylene naphthyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene stearyl ether, Polyoxyethylene alkyl esters such as oxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, sorbitan alkyl esters, glycerol mono Nonionic surfactants such as monoglyceride alkyl esters such as stearate and glycerol monooleate.
The content of these other surfactants in the developer is preferably from 0.1 to 10% by mass in terms of active ingredients.

(Chelating agent for divalent metals)
The developer according to the present invention preferably contains a chelating agent for a divalent metal, for example, for the purpose of suppressing the influence of calcium ions contained in hard water. Examples of the chelating agent for the divalent metal include Na ₂ P ₂ O ₇ , Na ₅ P ₃ O ₃ , Na ₃ P ₃ O ₉ , Na ₂ O ₄ P (NaO ₃ P) PO ₃ Na ₂ , Calgon (polymetaline). Polyphosphates such as ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, its amine salt; diethylenetriaminepentaacetic acid, its potassium salt, sodium salt; triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt Hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt; nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt; 1,3-diamino-2 -Propanol tetraacetic acid, its potassium salt, 2-phosphonobutanetricarboxylic acid-1,2,4, potassium salt thereof, sodium salt thereof; 2-phosphonobutanone tricarboxylic acid-2,3,4, 1-phosphonoethanetricarboxylic acid-1,2,2, potassium salt, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri Organic phosphonic acids such as (methylenephosphonic acid), its potassium salt, its sodium salt and the like, among others, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, its amine salt; ethylenediaminetetra (methylenephosphonic acid) ), Its ammonium salt, its potassium salt; hexamethyl Emissions diamine tetra (methylene phosphonic acid), an ammonium salt, its potassium salt is preferred.
The optimum amount of such a chelating agent varies depending on the hardness of the hard water used and the amount used, but is generally 0.01 to 5% by mass, more preferably 0% in the developing solution at the time of use. It is made to contain in the range of 0.01-0.5 mass%.

  Further, an alkali metal salt of an organic acid or an alkali metal salt of an inorganic acid may be added to the developer according to the present invention as a development regulator. For example, sodium carbonate, potassium, ammonium, sodium citrate, potassium, ammonium and the like may be used alone or in combination of two or more.

(Alkaline agent)
Examples of the alkaline agent used in the developer according to the present invention include tribasic sodium phosphate, potassium, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, potassium, ammonium, and lithium. Inorganic alkaline agents such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine And organic alkali agents such as diisotopanolamine, ethyleneimine, ethylenediamine, pyridine, and tetramethylammonium hydroxide. In the present invention, these may be used alone or in combination of two or more.

  Moreover, alkali silicate can be mentioned as alkali agents other than the above. Alkali silicates may be used in combination with a base. The alkali silicate to be used exhibits alkalinity when dissolved in water, and examples thereof include sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. These alkali silicates may be used alone or in combination of two or more.

The developer used in the present invention is composed of silicon oxide SiO ₂ which is a silicate component as a hydrophilizing component of a support and alkali oxide M ₂ O as an alkali component (M represents an alkali metal or ammonium group). By adjusting the mixing ratio and concentration, it can be easily adjusted to the optimum range. The mixing ratio (SiO ₂ / M ₂ O molar ratio) of silicon oxide SiO ₂ and alkali oxide M ₂ O is the amount of unclean dirt caused by excessive dissolution (etching) of the anodic oxide film of the support. From the viewpoint of suppressing the generation of insoluble gas resulting from complex formation between dissolved aluminum and silicate, the range is preferably 0.75 to 4.0, more preferably 0.75 to 3.5. Used in.

In addition, the alkali silicate concentration in the developer includes the effect of inhibiting dissolution (etching) of the anodic oxide film on the support, the developability, the effect of inhibiting precipitation and crystal formation, and the gelation during neutralization during waste From the viewpoint of the prevention effect and the like, the amount of SiO ₂ is preferably 0.01 to 1 mol / L, more preferably 0.05 to 0.8 mol / L with respect to the mass of the developer.

  In addition to the above components, the following components can be used in combination in the developer used in the present invention, if necessary. For example, benzoic acid, phthalic acid, p-ethylbenzoic acid, pn-propylbenzoic acid, p-isopropylbenzoic acid, pn-butylbenzoic acid, pt-butylbenzoic acid, pt-butylbenzoic acid Acids, p-2-hydroxyethylbenzoic acid, decanoic acid, salicylic acid, organic carboxylic acids such as 3-hydroxy-2-naphthoic acid; organic solvents such as propylene glycol; other reducing agents, dyes, pigments, water softeners And preservatives.

  The developer used in the present invention preferably has a pH in the range of 10 to 12.5 at 25 ° C, and more preferably in the range of pH 11 to 12.5. Since the developer in the present invention contains the surfactant, even if such a low pH developer is used, excellent developability is exhibited in the non-image area. Thus, by setting the pH of the developing solution to a relatively low value, damage to the image area during development is reduced and the handling property of the developing solution is excellent.

The conductivity x of the developer is preferably 2 <x <30 mS / cm, more preferably 5 to 25 mS / cm.
Here, it is preferable to add an alkali metal salt of an organic acid, an alkali metal salt of an inorganic acid, or the like as a conductivity adjusting agent for adjusting the conductivity.

  The developer can be used as a developer and a development replenisher for the exposed lithographic printing plate precursor, and is preferably applied to an automatic processor. When developing using an automatic developing machine, the developing solution becomes fatigued according to the amount of processing, so that the processing capability may be restored by using a replenishing solution or a fresh developing solution.

  Furthermore, in order to restore the processing capacity of the developer using an automatic developing machine, it is preferable to replenish by the method described in US Pat. No. 4,882,246. Developers described in JP-A-50-26601, 58-54341, JP-B-56-39464, 56-42860, and 57-7427 are also preferable.

  A more preferred development replenisher of the present invention contains an oxycarboxylic acid chelating agent having an ability to form a water-soluble chelate compound with aluminum ions, an alkali metal hydroxide, and a surfactant, and contains a silicate. A developing replenisher characterized by being an aqueous solution having a pH of 11 to 13.5. By using such a development replenisher, it has excellent developability and characteristics that do not impair the strength of the image area of the plate material, and is formed by elution of the aluminum support by the alkali of the developer. Precipitation of aluminum is effectively suppressed, adhesion of stains mainly composed of aluminum hydroxide to the surface of the developing bath roller of the automatic processor, and subsequent accumulation of aluminum hydroxide precipitates in the washing bath are reduced. It can be processed stably for a long time.

  The lithographic printing plate precursor thus developed is subjected to washing water, surface activity as described in JP-A Nos. 54-8002, 55-11545, 59-58431, and the like. It is post-treated with a desensitizing solution containing a rinse solution containing an agent and the like, gum arabic and starch derivatives. These treatments can be used in various combinations for the post-treatment of the lithographic printing plate precursor according to the invention. The planographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.

In the lithographic printing plate making method of the present invention, for the purpose of improving the image strength and printing durability, the image after development can be subjected to whole surface post-heating or whole surface exposure.
Very strong conditions can be used for heating after development. Usually, the heating temperature is 200 to 500 ° C. If the heating temperature after development is low, sufficient image strengthening action cannot be obtained, and if it is too high, problems such as deterioration of the support and thermal decomposition of the image area may occur.
The planographic printing plate obtained by the above processing is loaded on an offset printing machine and used for printing a large number of sheets.

  As a plate cleaner used for removing stains on the plate at the time of printing, a conventionally known plate cleaner for PS plate is used. For example, a multi cleaner, CL-1, CL-2, CP, CN-4, CN, CG-1, PC-1, SR, IC (made by Fuji Photo Film Co., Ltd.), etc. are mentioned.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited thereto.
[Example 1]
(Production of support)
The surface treatment shown below was performed using a JIS A 1050 aluminum plate having a thickness of 0.30 mm and a width of 1030 mm.

<Surface treatment>
In the surface treatment, the following various treatments (a) to (f) were continuously performed. In addition, after each process and water washing, the liquid was drained with the nip roller.

(A) The aluminum plate was etched at a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C. to dissolve the aluminum plate at 5 g / m ² . Thereafter, it was washed with water.
(B) A desmut treatment by spraying was performed with a 1% by mass aqueous solution of nitric acid having a temperature of 30 ° C. (including 0.5% by mass of aluminum ions), and then washed with water.

(C) An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous nitric acid solution (including 0.5% by mass aluminum ions and 0.007% by mass ammonium ions) at a temperature of 30 ° C. The AC power source was subjected to an electrochemical surface roughening treatment using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time TP of 2 msec until the current value reached a peak from zero and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode. The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 250 C / cm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Thereafter, it was washed with water.

(D) The aluminum plate was spray-etched at 35 ° C. with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass, the aluminum plate was dissolved at 0.2 g / m 2, and electrochemical using the alternating current in the previous stage. The smut component mainly composed of aluminum hydroxide generated during roughening was removed, and the edge portion of the generated pit was dissolved to smooth the edge portion. Thereafter, it was washed with water.
(E) A desmut treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.
(F) Anodization was performed for 50 seconds at a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions), a temperature of 33 ° C., and a current density of 5 (A / dm ² ). Thereafter, it was washed with water. At this time, the weight of the anodized film was 2.7 g / m ² .
The surface roughness Ra of the aluminum support thus obtained was 0.27 (measuring instrument: Surfcom manufactured by Tokyo Seimitsu Co., Ltd., stylus tip diameter 2 micrometer).

<Undercoat layer>
Next, the following undercoat layer coating solution was applied to the aluminum support with a wire bar and dried at 90 ° C. for 30 seconds. The coating amount was 10 mg / m ² .

(Coating solution for undercoat layer)
-Polymer compound A having the following structure: 0.05 g
・ Methanol 27g
・ Ion exchange water 3g

(Photosensitive layer)

Next, the following photosensitive layer coating solution [P-1] was prepared and applied to the above aluminum support using a wire bar. Drying was performed at 115 ° C. for 34 seconds with a hot air dryer to obtain a lithographic printing plate precursor. The coating amount after drying was 1.4 g / m ² .

<Photosensitive layer coating solution [P-1]>
・ Infrared absorber (IR-1) 0.074g
-Polymerization initiator (OS-12) 0.280g
・ Additive (PM-1) 0.151g
・ Polymerizable compound (AM-1) 1.00 g
・ Specific binder polymer (BT-1) 1.00g
・ Ethyl violet (C-1) 0.04g
・ Fluorine-based surfactant 0.015g
(Megafuck F-780-F Dainippon Ink and Chemicals,
Methyl isobutyl ketone (MIBK) 30% by mass solution)
・ Methyl ethyl ketone 10.4g
・ Methanol 4.83g
・ 10.4 g of 1-methoxy-2-propanol

  In addition, the polymerization initiator (OS-12) used for the said photosensitive layer coating liquid refers to what is mentioned as a compound example of the onium salt represented by the above-mentioned general formula (1). The structures of the infrared absorber (IR-1), additive (PM-1), polymerizable compound (AM-1), binder polymer (BT-1), and ethyl violet (C-1) are shown below. .

(Protective layer)
Synthetic mica (Somasif ME-100, 8% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.) and specific polyvinyl alcohol having a saponification degree of 91 mol% or more (Goselan CKS-50: saponification) 99 mol%, polymerization degree 300, sulfonic acid-modified polyvinyl alcohol Nippon Synthetic Chemical Industry Co., Ltd.) and a surfactant (Nihon Emulsion Co., Emalex 710) mixed aqueous solution (coating solution for protective layer) It apply | coated with the wire bar and it was made to dry with 125 degreeC 75 second with a warm air type drying apparatus.
The content ratio of mica solid content / specific polyvinyl alcohol / surfactant in this mixed aqueous solution (protective layer coating solution) is 18/80/2 (mass%), and the total coating amount is (after drying). The coating amount was 1.6 g / m ² .
This created a coated web.

  The coated web was cut as follows. A slitting device of FIG. 1 and a cutting blade of FIG. 2 are used to form a coiled coating web having a thickness of 0.3 mm and a width of 90 cm, with no interleaving paper interposed therebetween, and a width of 80 cm. The gap (D) was set as shown in Table 1, and both ends were continuously slit. Thereafter, it was cut into 110 cm (110 × 80 cm) to obtain a lithographic printing plate precursor. The sagging height (X) and the notch area (Y) of this plate were as shown in Table 1.

The obtained lithographic printing plate precursor was laminated without interposing the interleaving paper, and was changed by 0.15 at log E within a range of resolution 2400 dpi, external drum rotation speed 200 rpm, output 0-8 W with a Trendsetter 800II Quantum manufactured by Creo. And exposed. The exposure was performed under conditions of 25 ° C. and 50% RH.
After the exposure, neither heat treatment nor water washing treatment was performed, and development was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer used was a 1: 4 water diluted solution of DH-N, the developer replenisher was diluted 1: 1.4 water of FCT-421, and the finisher was 1: 1 of GN-2K manufactured by FUJIFILM Corporation. A water dilution was used.

The printing machine is a four-color tower-type rotary press CT7000 (170,000 machines) manufactured by Tokyo Kikai Co., Ltd., the ink is Dainippon Ink Co., Ltd. newspaper ink, and the dampening water is Toyo Ink Co., Ltd. Newspaper News King. After printing 100,000 copies using Alky (pH = 10.2), Oji Paper's “Tomakomai” (weight: 44 g / m ² ), blanket using Kinyo MP-75R, 2.07 mm, Visual sensory evaluation was performed based on the standard below the contamination corresponding to the end.
○: Practically preferred level △: Practical lower limit level ×: Impractical level

The setter transportability was evaluated according to the following criteria as to whether or not 150 plates could be continuously processed without problems with AMIZSETTER manufactured by NEC under the condition that the transport speed was 120 plates / hour.
○: All could be conveyed without any problem △: Three or fewer sheets could not be conveyed successfully ×: More than three sheets could not be conveyed successfully

  As can be seen from Table 1, none of the coated webs having the inorganic layered compound in the protective layer cut without intervening interstitial paper, or even if they occur, are above the practical level. (Examples 1 to 11). However, when the coated web having no inorganic layered compound in the protective layer is cut without interposing the interleaf, significant edge contamination occurs and becomes a practical problem (Comparative Example 1). Moreover, when it cuts through an interleaf, the subsequent interleaf removal process is needed and the objective of this invention cannot be achieved (comparative example 2).

It is sectional drawing which shows the cutting part of a slitter apparatus. It is a perspective view which shows one embodiment of the front-end | tip part shape of the lower side cutting blade of this invention. It is an enlarged view of A part of the front-end | tip part shape of the lower side cutting blade in FIG. It is a schematic sectional drawing which shows the shape of one embodiment of the photosensitive lithographic printing plate edge part of this invention.

Explanation of symbols

10a, 10b ...... Upper cutting blade 11 ... Rotating shaft 20 (20a, 20b) ... Lower cutting blade 21 ... Rotating shaft 25 ... Lower cutting blade 30 ... Lithographic printing plate

Claims (4)

  Lithographic printing produced by cutting a coated web in which a photosensitive layer and a protective layer containing an inorganic stratiform compound are laminated in this order on an aluminum support having a hydrophilic surface, and sandwiched in the plate thickness direction by a cutting member. A method for producing a lithographic printing plate precursor, characterized in that it is cut without interleaving paper on the surface of the protective layer of the coated web.   The cutting member has a pair of upper and lower cutting blades, the interval between the upper cutting blade and the lower cutting blade is set in a range of 30 to 100 μm, and the coating web is cut into a predetermined size. The method for producing a lithographic printing plate precursor as claimed in claim 1. The method for producing a lithographic printing plate precursor according to claim 1 or 2, wherein the photosensitive layer is a polymerizable negative photosensitive layer containing the following components (a) to (d).
(B) Infrared absorber (b) Polymerization initiator (c) Polymerizable compound (d) Binder polymer In a lithographic printing plate precursor in which a photosensitive layer and a protective layer containing an inorganic stratiform compound are provided in this order on an aluminum support having a hydrophilic surface, the opposing two or four side edges are from the photosensitive layer side to the lower surface side. It has a curved surface that is curved and bent in a direction away from the surface along the end, the cutting sag height of the curved portion in the cross section is 30 to 200 μm, and the notch area of the curved portion Is a lithographic printing plate precursor, characterized in that it is 200 to 100,000 μm ² .

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