JP4279656B2 - Image recording material and method for producing planographic printing plate precursor using the same - Google Patents

Description

  The present invention is particularly suitable for the production of a lithographic printing plate for scanning exposure suitable for a CTP system excellent in workability and economy, and is highly sensitive and can be used even under a safelight operation. In particular, it has a photopolymerizable layer and an oxygen-blocking layer on a support, and has both sensitivity and stability. The present invention relates to an excellent photopolymerizable image recording material and a method for producing a lithographic printing plate precursor using the photopolymerizable image recording material, capable of high sensitivity recording, and having excellent stability and safelight stability.

  With the progress of computer image processing technology, a photosensitive direct plate making system that directly forms a resist image by laser light or the like without outputting digital image information to a silver salt mask film has attracted attention. Various light sources from far ultraviolet to microwave are known as laser light. From the viewpoint of laser output, stability, cost, photosensitivity, etc., laser light that can be used for lithography is Ar ion laser, YAG laser, FD- One that emits infrared light from visible light, such as YAG laser, helium neon laser, and semiconductor laser, is prominent. For this reason, various compositions having photosensitivity to visible to infrared light have been studied.

  Among these, an image forming material having sensitivity to infrared laser light is promising. As an infrared laser-sensitive polymerizable composition, a combination of a cationic dye and a borate complex (for example, see Patent Documents 1 to 5), a combination of a photothermal conversion substance and an onium salt (for example, Patent Document 6, 7, etc.) are known. In these photopolymerizable compositions, undesired polymerization inhibition by oxygen is remarkable, and therefore, an oxygen-blocking protective layer is usually provided on the photopolymerizable composition layer. In order to obtain oxygen barrier properties, polyvinyl alcohol has been generally used as the protective layer because of its advantage that it has a high oxygen barrier and can be easily removed by dissolution in water.

Image forming materials using dyes that are sensitive to near-infrared light use near-infrared light as an energy source, so they can be handled under white or yellow light. In the photopolymerization type image forming material combined with the generator, the handleability is insufficient, and the time that can be handled under safelight is limited to within a few minutes. This is because at least a part of the photopolymerization-type image forming material in which a sensitizing dye and a radical generator are combined is considered to be polymerized in the photon mode, so that polymerization is started even with a small amount of visible light. This may cause an undesirable reaction such as a residual color in the non-image area.
In recent years, a photopolymerizable image-forming material has been disclosed that achieves both sensitivity and safelight safety by reducing the oxygen barrier properties of the oxygen barrier layer (see, for example, Patent Document 8). The quantitative value of oxygen permeability is not described, and there is a problem that the sensitivity is lowered when the humidity is high, and improvement of environmental stability has been desired.
JP-A-6-59450 JP-A-5-216227 JP-A-5-247110 JP-A-5-265204 JP-A-6-33217 JP-A-9-34110 Japanese Patent Laid-Open No. 9-134209 JP 2002-139443 A

  An object of the present invention is to provide a photopolymerizable image recording material that is excellent in both sensitivity and safe light safety and is not easily affected by the environment, and high sensitivity, safe light safety and environmental stability using the same. The object is to provide an excellent method for producing a lithographic printing plate precursor.

As a result of intensive studies in view of the above-mentioned object, the present inventor has found that when a protective layer containing a compound having a specific oxygen barrier property and absorbing in light of a specific wavelength is used as a protective layer, The present invention has been completed by finding the great advantage that the handling time in the bright room is greatly improved while maintaining the high sensitivity to the external laser and the sensitivity does not decrease even under exposure conditions under high humidity.
That is, the photopolymerizable image recording material of the present invention comprises, on a support, (A) a compound having an absorption maximum at 650 to 1300 nm, (B) a polymerization initiator, and (C) a light containing a polymerizable compound. A polymerizable layer, a compound having an oxygen permeability A at 25 ° C. and 1 atm of 0.2 ≦ A ≦ 20 (ml / m ² · day), and having an absorption maximum at 250 to 400 nm, and 500 And an oxygen barrier layer containing at least one of compounds having an absorption maximum at ˜700 nm.

Here, the oxygen barrier layer contains polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) or a derivative thereof, and the content ratio [PVA / PVP (or a derivative thereof)] B of both is 2 ≦ B ≦ 10 is preferable, and the saponification degree of PVA is preferably 85% or more.
In addition, as the (B) polymerization initiator, it is preferable to use a compound capable of generating an aryl radical.
Further, the method for producing a photosensitive lithographic printing plate precursor according to claim 5 of the present invention is a method for producing a photosensitive lithographic printing plate precursor using the photopolymerizable image recording material of the present invention as described above. A lithographic printing plate precursor is obtained by providing a photopolymerizable layer and an oxygen blocking layer thereon, and then winding the lithographic printing plate precursor in a state where the moisture content of the oxygen blocking layer is 7% or less. .

Although the operation of the present invention is not clear, it is presumed as follows.
The cause of the deterioration of safelight safety is considered to be the ultraviolet absorption of the polymerization initiator contained in the photosensitive layer or the light absorption of the colorant added to the photosensitive layer in order to provide plate inspection after plate making. It is done. Since the image recording material of the present invention has an oxygen blocking layer containing at least one of a compound having an absorption maximum at 250 to 400 nm and a compound having an absorption maximum at 500 to 700 nm on the photosensitive layer, a polymerization initiator or It seems that the harmful effect of the colorant by the side absorption of light is effectively suppressed.
In general, in a high-humidity environment, the oxygen barrier property of the protective layer decreases due to moisture absorption, and oxygen enters the photosensitive layer from outside the system, so that radicals generated by image formation (exposure) are released from outside the system. Quenched by incoming oxygen. Therefore, it is considered that the desired polymerization reaction is hindered and the sensitivity is lowered. In the present invention, it is considered that the decrease in sensitivity due to polymerization inhibition during the image formation is suppressed by providing an oxygen barrier layer in which oxygen permeability is controlled to a predetermined value. In other words, by controlling the oxygen permeability to a predetermined value, even when a small amount of radicals are generated by, for example, safelight, the radicals are effectively deactivated without reducing the sensitivity during image formation. It is thought that it can be made to.
Furthermore, when an aryl radical generator is used as the polymerization initiator, the reactivity of the generated radical is very high, so that the photopolymerizable layer can be polymerized before being subjected to polymerization inhibition by oxygen. It is presumed that an effect of suppressing sensitivity reduction can be obtained.

Since the photopolymerizable image recording material of the present invention comprises an oxygen barrier layer containing a compound having a specific oxygen permeability and absorbing light of a specific wavelength, sensitivity and safelight safety can be achieved. Both are excellent and environmental stability is good.
In addition, according to this method for producing a photopolymerizable image recording material, a lithographic printing plate precursor provided with a photopolymerizable layer and an oxygen blocking layer is wound under specific conditions, thereby providing high sensitivity, safe light safety, and environmental protection. A photosensitive lithographic printing plate precursor having excellent stability can be produced.

Hereinafter, the present invention will be described in detail.
The photopolymerizable image recording material of the present invention can be obtained by sequentially laminating a photopolymerizable layer and an oxygen blocking layer (protective layer) on a support. The photopolymerizable layer includes, as essential components, (A) a compound having an absorption maximum at 650 to 1300 nm (infrared absorber), (B) a polymerization initiator, (C) a polymerizable compound, and (D) as necessary. Consists of a binder polymer and other additives.
The photopolymerizable image recording material of the present invention may have a photopolymerizable layer and an oxygen barrier layer in this order on the support, and other layers (for example, an intermediate layer, a back layer, etc.) depending on the purpose. A coating layer, etc.) can be provided at any position.
In the present invention, it is preferable to use a compound capable of generating an aryl radical as the polymerization initiator, and it is particularly preferable to use an onium salt compound, especially a sulfonium salt compound.

(Photopolymerizable layer)
Hereinafter, each component contained in the photopolymerizable layer will be sequentially described.
(A) Compound having an absorption maximum at 650 to 1300 nm In the photopolymerizable layer according to the present invention, it is essential to use a compound having an absorption maximum at 650 to 1300 nm, that is, an infrared absorber.
This compound has a function of converting absorbed infrared rays into heat. The heat generated at this time causes a polymerization initiator (radical generator) described later to thermally decompose to generate radicals. As the infrared absorber used in the present invention, it is preferable to use a dye or a pigment having an absorption maximum at a wavelength of 650 to 1300 nm, more preferably from 760 nm to 1200 nm. Such a dye or pigment is hereinafter referred to as an infrared absorber as appropriate.

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

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

  Further, other preferable examples of the infrared absorbing dye used in the present invention include specific indolenine cyanine dyes described in Japanese Patent Application No. 2001-6326 specification and JP-A No. 2002-278057 as exemplified below. Can be mentioned.

  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 general 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. Here, the hetero atom represents N, S, O, a halogen atom, or Se. Ph represents a phenyl group.

X _a ^- is Z _a which will be described below ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.
R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Z _a ^- represents a counter anion. However, when the cyanine dye represented by formula (a) has an anionic substituent in the structure thereof, Z _a is does not require charge neutralization ^- is not necessary. Preferred Z _a ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, in view of storage stability of the recording layer coating solution. Hexafluorophosphate 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. be able to.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in Japanese Patent Application No. 2001-6326 and Japanese Patent Application Laid-Open No. 2002-278057.

  Moreover, when using a pigment as an infrared absorber, if it has absorption in the wavelength of 650-1300 nm, it can select and use a well-known thing suitably without a restriction | limiting. Of these, preferred examples include phthalocyanine pigments and carbon black.

When these infrared absorbers are applied to the photopolymerizable layer of the photopolymerizable image recording material of the present invention, they may be added to the same layer as other components, or another layer is provided and added thereto. However, when this image recording material is used as a negative lithographic printing plate precursor, the absorbance at the maximum absorption wavelength in the wavelength range of 760 nm to 1200 nm of the photopolymerizable layer is 0.5 to 1. It is preferable to add so that it exists in the range of 2, More preferably, it is the range of 0.6-1.15. When the absorbance is within this range, the strength of the image area and the adhesion between the support and the photopolymerizable layer are excellent, and a sufficient number of printed sheets can be secured during printing.
The absorbance of the photopolymerizable layer can be adjusted by the amount of the infrared absorber added here and the thickness of the photopolymerizable layer. Absorbance can be measured by a conventional method. As a measuring method, for example, on a reflective support such as aluminum, a photopolymerizable layer having a thickness appropriately determined in a range where the coating amount after drying is necessary as a lithographic printing plate is formed, and the reflection density is optically measured. Examples thereof include a method of measuring with a densitometer, a method of measuring with a spectrophotometer by a reflection method using an integrating sphere, and the like.

Further, the infrared absorbent according to the present invention needs to be contained in the photopolymerizable layer so that the absorbance (OD _x ) described later can be controlled within a predetermined range. As addition amount with respect to solid content, the range of 0.5-10.0 mass% is preferable, The range of 1.0-5.0 mass% is more preferable, The range of 1.5-4.0 mass% is further preferable.

(B) Polymerization initiator The polymerization initiator used in the photopolymerizable layer according to the present invention is a combination of the above-mentioned infrared absorbers and a compound that generates radicals when irradiated with an infrared laser (radical generator). Point to. Examples of the radical generator include onium salts, halomethyl group-containing compounds, peroxides, azo polymerization initiators, azide compounds, quinonediazides, and organic boron anions. In the present invention, among such polymerization initiators, it is preferable to use a compound capable of generating an aryl radical in that it is less susceptible to environmental temperature and humidity, and as such a compound, the onium salt, Examples thereof include organic boron anions, and among them, onium salts, particularly sulfonium salts are preferable in terms of storage stability.
Examples of the organic boron anion include those described in JP-A-62-143044, JP-A-62-1050242, JP-A-5-5988, JP-A-5-197069 and the like. . Examples of the halomethyl group-containing compound include those described in JP-A-4-31863.

Hereinafter, onium salts that can be suitably used as the polymerization initiator in the present invention will be described.
Preferred onium salts include iodonium salts, diazonium salts, and sulfonium salts. In the present invention, these onium salts function not as acid generators but as radical polymerization initiators. The onium salt suitably used in the present invention is an onium salt represented by the following general formulas (I) to (III).

In general formula (I), Ar ¹ and Ar ² 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 ¹ ) ⁻ 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.

In general formula (II), Ar ³ 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 ² ) ⁻ represents a counter ion having the same meaning as (Z ¹ ) ⁻ .

In general formula (III), R ²³ , R ²⁴ and R ²⁵ 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 ³ ) ⁻ represents a counter ion having the same meaning as (Z ¹ ) ⁻ .

  In the present invention, specific examples of onium salts that can be suitably used as a radical generator include those described in paragraphs [0030] to [0033] of JP-A No. 2001-133969.

  The 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 setting the absorption wavelength in the ultraviolet region in this way, the photopolymerizable image recording material of the present invention and the lithographic printing plate precursor using the same can be handled under white light.

  These radical generators are used in an amount of 0.1 to 50% by weight, preferably 0.5 to 30% by weight, and particularly 0.5 to 30% by weight, based on the total solid content of the photopolymerizable layer coating liquid, from the viewpoints of sensitivity and soiling of non-image areas. Preferably, it can be added to the photopolymerizable layer coating solution at a ratio of 1 to 20% by mass. These radical generators may be used alone or in combination of two or more. Moreover, these radical generators may be added to the same layer as other components, or another layer may be provided and added thereto.

  In addition to the above-mentioned radical generators used as polymerization initiators in the present invention, JP 2002-148790 A, JP 2002-148790 A, JP 2002-350207 A, JP 2002-6482 A. The specific aromatic sulfonium salt described in the gazette etc. is also used suitably.

(C) Polymerizable compound The polymerizable compound used in the photopolymerizable layer according to the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and has at least one ethylenically unsaturated bond. , Preferably selected from compounds having two or more. Such compound groups are widely known in the industrial field, and these can be used without any particular limitation in the present invention. These also include those having 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, and JP-A-59-5240. And those having an aromatic skeleton described in JP-A-59-5241, JP-A-2-226149, and those containing an amino group described in JP-A-1-165613. Used. Furthermore, the ester monomers described above can also be used as a mixture.

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

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinyl urethane containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (4) to a polyisocyanate compound having two or more isocyanate groups. Compounds and the like.

^{_{CH 2 = C (R 1)}} COOCH 2 CH (R 2) OH Formula (4)
(However, R ¹ and R ² represent H or CH _3. )

  Further, urethane acrylates as described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 And urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Thus, a photopolymerizable layer having a very excellent curing reaction rate can be formed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493. Etc. 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.

  For these addition-polymerizable compounds, details on how to use them, such as what type of structure is used, whether they are used alone or in combination, and how much is added, match the performance design of the final photopolymerizable layer. Can be set arbitrarily. 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 area, that is, the cured film, those having three or more functionalities are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrenic compound, vinyl ether). It is also effective to adjust both photosensitivity and strength by using a compound of the type). 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, for the compatibility and dispersibility with other components in the composition constituting the photopolymerizable layer (for example, binder polymer, initiator, colorant, etc.), the method for selecting and using the addition polymerization compound is as follows: This is an important factor. For example, the compatibility may be improved by using a low-purity compound or using two or more kinds in combination.
In addition, when the photopolymerizable image recording material of the present invention is applied to a lithographic printing plate precursor, a specific structure may be selected for the purpose of improving the adhesion of a support or an oxygen barrier layer described later.

  As for the compounding ratio of the addition polymerizable compound in the composition constituting the photopolymerizable layer, a larger amount is advantageous in terms of sensitivity, but if it is too large, undesirable phase separation may occur or the lithographic printing plate precursor Causes problems in the manufacturing process due to the adhesiveness of the photopolymerizable layer (for example, transfer of photopolymerizable layer components, manufacturing defects due to adhesion), and precipitation from the developer. sell. From these viewpoints, the addition polymerizable compound (C) is preferably in the range of 5 to 80% by mass, more preferably 25 to 75% by mass, based on the total solid content in the composition constituting the photopolymerizable layer. Used in. These may be used alone or in combination of two or more. In addition, the use method of the addition polymerizable compound can arbitrarily select an appropriate structure, blending, and addition amount from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface adhesiveness, and the like. Furthermore, when this image recording material is applied to a lithographic printing plate precursor, a layer configuration / coating method such as undercoating or overcoating can be carried out.

[(D) Binder polymer]
It is preferable to add a binder polymer to the photopolymerizable layer according to the present invention for the purpose of improving film properties. As the binder polymer, a linear organic polymer is preferably used. As such a “linear organic polymer”, a known one can be arbitrarily used. Preferably, a linear organic polymer that is soluble or swellable in water or alkali water is selected in order to enable water development or alkali water development. The linear organic polymer is selected and used not only as a film forming agent for forming the photopolymerizable layer, but also according to the use as water, alkaline water or an organic solvent developer. For example, when a water-soluble organic polymer is used, water development becomes possible. Examples of such linear organic polymers include radical polymers having a carboxylic acid group in the side chain, such as JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, and JP-B-54-25957. , JP-A-54-92723, JP-A-59-53836, JP-A-59-71048, ie, methacrylic acid copolymer, acrylic acid copolymer, itacon Examples include acid copolymers, crotonic acid copolymers, maleic acid copolymers, and partially esterified maleic acid copolymers. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to a polymer having a hydroxyl group are useful.

  Among these, a (meth) acrylic polymer having a benzyl group or an allyl group and a carboxyl group in the side chain is particularly preferable because of excellent balance of film strength, sensitivity, and developability.

  In addition, Japanese Patent Publication No. 7-2004, Japanese Patent Publication No. 7-120041, Japanese Patent Publication No. 7-120042, Japanese Patent Publication No. 8-12424, Japanese Patent Laid-Open No. 63-287944, Japanese Patent Laid-Open No. 63-287947, Japanese Patent Laid-Open No. The urethane-based binder polymer containing an acid group described in each publication of JP 271741 A, JP-A No. 13-312062 and the like is very excellent in strength, and is advantageous in terms of printing durability and suitability for low exposure. .

  In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble linear organic polymer. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful.

The weight average molecular weight of the binder polymer used in the present invention is preferably 5,000 or more, more preferably 10,000 to 300,000, and the number average molecular weight is preferably 1,000 or more, More preferably, it is the range of 2,000-250,000. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1 or more, and more preferably 1.1 to 10.
These polymers may be random polymers, block polymers, graft polymers, or the like, but are preferably random polymers.

The binder polymer used as desired in the photopolymerizable layer according to the present invention can be synthesized by a conventionally known method. Solvents used in the synthesis include, for example, tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy. Examples include 2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, and water. These solvents are used alone or in combination of two or more.
As the radical polymerization initiator used in synthesizing the polymer used in the present invention, known compounds such as azo initiators and peroxide initiators can be used.

  The binder polymer used in the present invention may be used alone or in combination. When these polymers are added to the photopolymerizable layer, the addition amount is in the range of 20 to 95% by mass with respect to the total solid content of the photopolymerizable layer coating solution from the viewpoint of improving image formability and image portion strength. It is preferable that the range is 30 to 90% by mass. The (C) polymerizable compound and the (D) linear organic polymer are preferably in the range of 1/9 to 7/3 by mass ratio.

  In addition to the above essential components, other components suitable for the application, production method and the like can be appropriately added to the photopolymerizable layer according to the present invention. Hereinafter, preferred additives will be exemplified.

(Polymerization inhibitor)
In the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor for the purpose of preventing undesired thermal polymerization of the polymerizable compound (C). Examples of suitable thermal polymerization inhibitors that can be used here include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4′-thiobis (3- Methyl-6-tert-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 solid content in the composition constituting the photopolymerizable layer.
If necessary, in order to prevent polymerization inhibition by oxygen, higher fatty acid derivatives such as behenic acid and behenic acid amide are added and unevenly distributed on the surface of the photopolymerizable layer in the drying process after coating. May be. 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 entire composition.

[Colorant]
A colorant such as a dye or a pigment may be added to the photopolymerizable layer according to the present invention for the purpose of coloring. Thereby, so-called plate inspection properties such as visibility after plate making and suitability for an image density measuring machine as a printing plate can be improved. Specific examples include pigments such as phthalocyanine pigments, azo pigments, carbon black and titanium oxide, and dyes such as ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The addition amount of the dye and the pigment as the colorant is preferably in the range of about 0.5% by mass to about 5% by mass with respect to the total solid content in the composition of the photopolymerizable layer.

In the photopolymerizable image recording material of the present invention, the photopolymerizable layer is provided on a support. As described above, the photopolymerizable layer according to the present invention contains (A) a compound having an absorption maximum at 650 to 1300 nm, (B) a polymerization initiator, and (C) a polymerizable compound as essential components. Preferably, it further contains (D) a binder polymer. This negative photopolymerizable layer forms an image by a mechanism in which a polymerization initiator is decomposed by heat or light to generate radicals, and a polymerizable compound causes a polymerization reaction by the generated radicals.
The photopolymerizable image recording material of the present invention is suitably applied to a negative lithographic printing plate precursor, and such a lithographic printing plate precursor is used for plate making by direct writing with a laser beam having a wavelength of 300 to 1,200 nm. In particular, it exhibits high printing durability and image formability as compared with conventional lithographic printing plate precursors.

  When coating the above photopolymerizable layer on a support, each component of the composition constituting the above photopolymerizable layer is dissolved in an appropriate organic solvent and applied onto the support or intermediate layer. That's fine. 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 coating solution is suitably 2 to 50% by mass.

The coating amount of the photopolymerizable layer mainly affects sensitivity, developability, exposure film strength and printing durability, and is preferably selected according to the intended use. If the coating amount is too small, the printing durability tends to decrease. If the coating amount is too large, the sensitivity tends to decrease, and it takes time for exposure and a longer time for development processing. Is concerned. As the photopolymerizable negative lithographic printing plate precursor for scanning exposure which is the main object of the present invention, the coating amount of the photopolymerizable layer is about 0.1 g / m ² to about 10 g / m ² in terms of the mass after drying. A range is suitable, More preferably, it is 0.5-5 g / m < ² >.

As the physical properties of the photopolymerizable layer in the photopolymerizable image recording material of the present invention, the developing speed of the unexposed area with respect to an alkaline developer having a pH of 10 to 13.5 is 80 nm / sec or more, and the alkali developer It is preferable that the penetration rate in the exposed area is 100 nF / sec or less.
Here, the development rate with an alkaline developer having a pH of 10 to 13.5 is a value obtained by dividing the film thickness (m) of the photopolymerizable layer by the time required for development (sec), and the penetration rate of the alkaline developer and Is a value indicating the rate of change in capacitance (F) when the photopolymerizable layer is formed on a conductive support and immersed in a developer.
Hereinafter, a method for measuring “development speed with respect to an alkali developer” and “penetration speed of an alkali developer” in the present invention will be described in detail.

<Measurement of development speed for alkaline developer>
Here, the development speed of the photopolymerizable layer with respect to the alkaline developer is a value obtained by dividing the film thickness (m) of the photopolymerizable layer by the time (sec) required for development.
As a method for measuring the developing speed in the present invention, as shown in FIG. 1, an alkaline developer (with an unexposed photopolymerizable layer on an aluminum support having a pH in the range of 10 to 13.5 ( (30 ° C.), and the dissolution behavior of the photopolymerizable layer was investigated with a DRM interference wave measuring apparatus. FIG. 1 shows a schematic diagram of a DRM interference wave measuring apparatus for measuring the dissolution behavior of the photopolymerizable layer. In the present invention, a change in film thickness was detected by interference using light of 640 nm. When the development behavior is non-swelling development from the surface of the photopolymerizable layer, the film thickness gradually decreases with respect to the development time, and an interference wave corresponding to the thickness is obtained. Further, in the case of swelling dissolution (film removal dissolution), the film thickness changes due to the penetration of the developer, so that a clean interference wave cannot be obtained.

The measurement is continued under these conditions, and the development speed is calculated from the time (s) until the photopolymerizable layer is completely removed and the film thickness becomes 0 (development completion time) and the film thickness (nm) of the photopolymerizable layer. Can be obtained by the following equation. It is determined that the higher the development speed, the easier the film is removed by the developer and the better the developability.
Development speed (of unexposed area) = [photopolymerizable layer thickness (nm) / recording completion time (sec)]

<Measurement of penetration rate of alkali developer>
The permeation rate of the alkali developer is a value indicating the rate of change of the capacitance (F) when the photopolymerizable layer is formed on a conductive support and immersed in the developer.
As shown in FIG. 2, the method for measuring the capacitance, which is a measure of permeability in the present invention, is as follows. On an aluminum support in a certain alkaline developer (28 ° C.) in the range of pH 10 to 13.5. There is a method of performing exposure at a predetermined exposure amount, immersing one provided with a cured photopolymerizable layer as one electrode, connecting a lead wire to an aluminum support, and applying a voltage using a normal electrode on the other. Can be mentioned. After the voltage is applied, the developer permeates the interface between the support and the photopolymerizable layer as the immersion time elapses, and the capacitance changes.

From the time (s) required until this capacitance changes and the saturation value (nF) of the capacitance of the photopolymerizable layer, the following equation can be used. It is determined that the smaller the permeation rate, the lower the permeability of the developer.
Developer penetration rate (of exposed area) =
[Saturation value of capacitance of photopolymerizable layer (nF) / Time required for capacitance change to be constant (s)]

As a preferable physical property of the photopolymerizable layer in the lithographic printing plate precursor according to the invention, the development rate of the unexposed area with an alkaline developer having a pH of 10 to 13.5 by the above measurement is preferably 80 to 400 nm / sec. The permeation rate of the alkali developer into the photopolymerizable layer is preferably 90 nF / sec or less.
Further, the development rate of the unexposed area with an alkaline developer having a pH of 10 to 13.5 as measured above is more preferably 90 to 200 nm / sec, and the penetration rate of the similar alkaline developer into the photopolymerizable layer is 80 nF / It is preferable that it is sec or less.
The upper limit of the development speed or the lower limit of the permeation speed is not particularly limited, but considering the balance between the two, the development speed of the unexposed area is more preferably in the range of 90 to 200 nm / sec. The permeation rate of the alkali developer into the photopolymerizable layer is preferably 80 nF / sec or less.

Control of the development rate of the unexposed part of the photopolymerizable layer and the penetration rate of the alkali developer into the photopolymerizable layer after curing can be performed by a conventional method. Addition of a hydrophilic compound is useful for improving the development speed, and means for adding a hydrophobic compound is useful for suppressing the penetration of the developer into the exposed area.
In the present invention, photopolymerization is performed by adjusting the type and content of the compound contained in the photopolymerizable layer such as (A) infrared absorber, (B) polymerization initiator, and (C) polymerizable compound. The development speed of the conductive layer and the penetration speed of the developer can be easily controlled within the above preferred ranges.

[Support]
As the support used in the photopolymerizable image recording material of the present invention, any conventionally known hydrophilic support used in a lithographic printing plate precursor can be used.
The support used is preferably a dimensionally stable plate, for example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc). , Copper, etc.), plastic films (for example, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.) Examples include paper or plastic film on which such a metal is laminated or vapor-deposited. If necessary, these support surfaces may be subjected to appropriate known physical and chemical treatments for the purpose of imparting hydrophilicity or improving strength.

  In particular, preferred supports include paper, polyester film or aluminum plate, among which dimensional stability is good, relatively inexpensive, and a surface with excellent hydrophilicity and strength is provided by surface treatment as required. An aluminum plate that can be used is particularly 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 suitable for the support in the present invention is a metal plate mainly composed of dimensionally stable aluminum. In addition to a pure aluminum plate, an alloy mainly composed of aluminum and containing a trace amount of foreign elements. A plate or aluminum (alloy) is selected from laminated or vapor-deposited plastic film or paper. In the following description, the above-described substrates made of aluminum or aluminum alloy are collectively referred to as an aluminum substrate. Examples of the foreign element contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is 10% by mass or less. In the present invention, a pure aluminum plate is suitable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element.

Thus, the composition of the aluminum plate applied to the present invention is not specified, and it is a conventionally known material 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. The aluminum support may or may not be subjected to a support surface treatment described below as appropriate.

(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. 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, the temperature is preferably 50 to 90 ° C. and the concentration is 15 to 65 mass as described in JP-A-53-12739. And a method of alkali etching described in Japanese Patent Publication No. 48-28123. After the treatment as described above, the method condition is not particularly limited as long as the center line average roughness Ra of the treatment surface is 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 usually anodized.
In the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, or an aqueous solution of boric acid / sodium borate is used as a main component of the electrolytic bath singly or in combination. 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. Conditions can be selected.

As the hydrophilization treatment of the support surface, widely known methods can be applied. 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 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 fluoride titanium, potassium 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. A support having electrolytic grains as disclosed in JP-B-46-27481, JP-A-52-58602, and JP-A-52-30503, and the above-mentioned anodizing treatment and hydrophilization treatment A combined surface treatment is also useful.

[Intermediate layer (undercoat layer)]
In the photopolymerizable image recording material of the present invention, an intermediate layer (undercoat layer) may be provided for the purpose of improving adhesion between the photopolymerizable layer and the support and soiling. 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 Nos. 11-84684, 11-327152, 2000-10292, 2000-235254, 2000-352824, 2001-209170, etc. Can do.

(Oxygen barrier layer)
In the present invention, it is necessary to provide an oxygen blocking layer on the photopolymerizable layer.
Hereinafter, the oxygen barrier layer, which is a characteristic component of the present invention, will be described.
The oxygen barrier layer used in the present invention has an oxygen permeability A at 25 ° C. and 1 atm of 0.2 ≦ A ≦ 20 (ml / m ² · day), and has an absorption maximum at 250 to 400 nm. It contains at least one of a compound and a compound having an absorption maximum at 500 to 700 nm. Since the oxygen-blocking layer has the above-mentioned characteristics, the photopolymerizable image recording material of the present invention has high sensitivity recording, unnecessary polymerization reaction during production and raw storage, and effective fogging during image exposure. Suppression can be achieved.
In addition to the oxygen permeability described above, the oxygen blocking layer has a desired property that it does not substantially impede transmission of light used for exposure, and is a photopolymerizable layer (hereinafter also simply referred to as “photosensitive layer”). It is desirable that it has excellent adhesion and can be easily removed in the development process after exposure. Such an oxygen barrier layer has been conventionally devised and described in detail in US Pat. No. 3,458,311 and JP-A-55-49729.

  As a material that can be used for the oxygen blocking layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, vinyl alcohol / vinyl phthalate copolymer, vinyl acetate / Examples include water-soluble polymers such as vinyl alcohol / vinyl phthalate copolymer, vinyl acetate / crotonic acid copolymer, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, polyacrylic acid, polyacrylamide, etc. Can be used alone or in combination. Of these, the use of polyvinyl alcohol as the main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability.

  The polyvinyl alcohol used for the oxygen barrier layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. Specific examples of polyvinyl alcohol include those that are hydrolyzed by 71 to 100% and have a polymerization repeating unit in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA- 420, PVA-613, L-8 and the like.

In addition, a carboxyl group-modified type, a cation-modified type, an acetoacetyl-modified type, a sulfonic acid-modified type, etc. of polyvinyl alcohol can be suitably used. Specific examples thereof include T-330H, T-330ST, T-350, T-230, T-215, K-210, Z-200, Z-200H, Z-210, Z-100, F-78. (Both manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).
The content of the polyvinyl alcohol in the oxygen barrier layer is preferably in the range of 50 to 100% by mass, more preferably in the range of 70 to 90% by mass in terms of solid content.

Examples of resin components other than the polyvinyl alcohol contained in the oxygen blocking layer include water-soluble polymers such as cellulose, polyvinyl pyrrolidone, gelatin, polyacrylic acid, polyacrylamide, and vinyl pyrrolidone / vinyl acetate copolymer, polyethylene, and polypropylene. And water-insoluble polymer compounds such as polyethylene terephthalate, polystyrene, polycarbonate, nylon, polyamide, and silicone.
Usually, since the oxygen blocking layer is removed with water during image formation, the layer itself is preferably water-soluble. Therefore, the resin used in combination with polyvinyl alcohol preferably also contains a water-soluble polymer. In a more preferred embodiment, 50% or more of the resin components other than polyvinyl alcohol contained in the oxygen blocking layer is a water-soluble polymer.

High adhesion between the oxygen blocking layer and the photopolymerizable layer is advantageous in terms of printing durability, and from this viewpoint, as a resin used in combination with polyvinyl alcohol, a water-soluble polymer containing vinylpyrrolidone as a structural unit is used. Preferable examples include polyvinylpyrrolidone and a copolymer of vinylpyrrolidone and vinyl acetate.
When a water-soluble polymer containing polyvinyl pyrrolidone as a structural unit is used, the proportion of the vinyl pyrrolidone unit structure in the oxygen barrier layer is not particularly limited, but is usually 5 to 30% by mass, preferably 10 to 25% by mass. %, And more preferably in the range of 15 to 20% by mass.

  In the protective layer, various organic compounds and inorganic compounds may be added in addition to polyvinyl alcohol and other resin components. Further, a surfactant may be added for the purpose of improving the coating property for coating on the photopolymerizable composition.

Components of the oxygen barrier layer (selection of PVA, use of additives), coating amount, and the like are selected in consideration of fogging, adhesion, and scratch resistance in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of the PVA used (the higher the content of unsubstituted vinyl alcohol units in the oxygen barrier layer), the higher the film thickness, the higher the oxygen barrier property, which is advantageous in terms of sensitivity. However, when the oxygen barrier property is extremely increased, there arises a problem that unnecessary polymerization reaction occurs during production and raw storage, and unnecessary fogging and image line thickening occur during image exposure.
The oxygen barrier layer in the present invention must have an oxygen permeability A at 25 ° C. and 1 atm of 0.2 ≦ A ≦ 20 (ml / m ² · day), preferably 1 ≦ A ≦ 12 (ml / M ² · day), more preferably 2 ≦ A ≦ 8 (ml / m ² · day).

The oxygen permeability A is controlled by using a resin having a lower oxygen barrier than polyvinyl alcohol (PVA) in combination with polyvinyl alcohol having a higher oxygen barrier, and adjusting the content ratio between the two. In particular, it is preferable to use the above-described polyvinyl pyrrolidone (PVP) or a derivative thereof as a resin having a low oxygen barrier property. Here, the ratio B of PVA / PVP (or a derivative thereof) is preferably 2 ≦ B ≦ 10. More preferably, 3 ≦ B ≦ 7.
From the same viewpoint, the degree of saponification of PVA used in the oxygen barrier layer according to the present invention is preferably 85% or more, more preferably 90% or more, and still more preferably 95% or more. The higher the degree of saponification of PVA, the higher the water resistance and the better the storage stability under high humidity.
The molecular weight of the (co) polymer such as polyvinyl alcohol (PVA) used here can be in the range of 2000 to 10 million, preferably in the range of 10,000 to 1 million, preferably 20,000. More preferable is 100,000.

  In addition, the oxygen barrier layer according to the present invention has a compound having an absorption maximum at 250 to 400 nm (ultraviolet region) and an absorption maximum at 500 to 700 nm (visible region) for the purpose of further improving safety light safety. At least one of the compounds (hereinafter, these compounds may be collectively referred to as “specific light absorber”) needs to be added.

Although the mechanism of action is not clear, the oxygen blocking layer according to the present invention suppresses unnecessary fogging (non-image portion residual color) that occurs during handling of the photopolymerizable image recording material by adding a specific light absorber. It is thought to do. This is considered to be because the specific light absorber functions as a filter that absorbs ultraviolet light and visible light that cause the above-described fogging, and reduces the entry of these lights into the photosensitive layer.
First, a compound having an absorption maximum at 250 to 400 nm (hereinafter referred to as “ultraviolet absorber” as appropriate) used for suppressing fogging by ultraviolet light will be described.

<Compound having absorption maximum at 250 to 400 nm>
The ultraviolet absorber used in the present invention is not particularly limited as long as it is a compound having a maximum absorption wavelength of 250 to 400 nm, but is preferably a compound having an absorption maximum at 300 to 400 nm, more preferably used for exposure. A compound that does not substantially inhibit light transmission and has no absorption in the wavelength range of 840 to 1200 nm is preferable.
Among them, preferred ultraviolet absorbers in the present invention are dyes having an absorption maximum at 350 to 400 nm. Specific examples include JP-A-62-210458, JP-A-63-104046, JP-A-63-103235, JP-A-62-43704, JP-A-62-218648, JP-A-63-306436, JP-A-63-3. And UV absorbing dyes described in No. 314535.

  For example, a benzotriazole compound substituted with an aryl group, a 4-thiazolidone compound, a benzophenone compound, a cinnamic acid ester compound, a butadiene compound, a benzoxazole compound, and an ultraviolet absorbing polymer can be used.

  Further, as an ultraviolet absorbing dye that is particularly preferably used as an ultraviolet absorber, a compound represented by the following general formula [1-a], [1-b], [1-c] or [1-d] is used and the absorption maximum The compound whose is is 300-400 nm is mentioned.

In the formula, R ^1a is an atomic group represented by —OX or —N (X) (Y), and X and Y are a hydrogen atom, an alkyl group, a cyanoalkyl group, a carboxyalkyl group, a sulfoalkyl group, a hydroxy group, Represents an alkyl group, a halogenated alkyl group, an optionally substituted alkyl group or a sodium / potassium salt thereof, and R ^2a and R3 ^3a represent a hydrogen atom, a halogen atom, an alkyl group, a hydroxy group, an alkoxy group, an alkylthio group, or Represents the same group as the -OX group, and Q represents a phenyl group or a sulfoalkyl group substituted with at least one halogen atom, a carboxy group, a sulfo group, or a sulfoalkyl group or a sodium / potassium salt thereof, or a sulfoalkoxyalkyl. Group, a sulfoalkylthioalkyl group, and L represents an optionally substituted methine group. R ^4a represents an alkyl group, a carboxy group, an alkyloxycarbonyl group, or an acyl-substituted or unsubstituted amino group. m represents an integer 1 or 2, and n represents an integer 0 or 1, respectively.

In the formula, R ^1b , R ^2b , R ^3b , R ^4b and R ^5b are a hydrogen atom, a halogen atom, an alkyl group, a hydroxyl group, an alkoxy group, an amino group, an acylamino group, a carboxyl group or a sulfone group, or a sodium / potassium salt thereof. R represents an alkyl group or a carboxyl group.

In the formula, R ^1c and R ^2c represent an alkyl group, a substituted alkyl group, an aryl group, an alkoxycarbonyl group or a carboxyl group, and R ^3c and R ^4c represent an alkyl group or a sulfonic acid group substituted with a sulfonic acid group or a carboxyl group. Alternatively, it represents an aryl group substituted with a carboxyl group or a sulfonic acid group or a sodium / potassium salt thereof, and L represents a substituted or unsubstituted methine chain. M represents a sodium, potassium or hydrogen atom, and l represents 0 or 1.

In the formula, R ^1d , R ^2d , R ^3d and R ^4d represent an alkyl group, a hydroxyalkyl group, a cyano group, an alkylcyano group, an alkoxy group and a sulfoalkyl group. R ^5d and R ^6d represent a sulfonic acid group or an alkyl sulfonic acid group.

  Specific examples of compounds (1-1) to (1-27) of dyes preferably used in the present invention are shown below, but the present invention is not limited thereto.

Since the oxygen barrier layer according to the present invention is water-soluble, the ultraviolet absorber used is also preferably a water-soluble compound. Further, since the photosensitive layer is insoluble in water, the ultraviolet absorber is not mixed into the adjacent photosensitive layer, and there is no concern that the ultraviolet absorber will have an undesirable effect on the photosensitive layer.
From the viewpoint of the effect of the present invention and the physical strength of the oxygen blocking layer, such an ultraviolet absorber is preferably added to the oxygen blocking layer coating solution in an amount of about 5 to 40% by mass in terms of solid content. It is more preferable to add 35% by mass, and it is most preferable to add 15 to 25% by mass.
Next, a compound having an absorption maximum at 500 to 700 nm (hereinafter referred to as “visible light absorber” as appropriate) used for suppressing fogging by visible light will be described.

<Compound having absorption maximum at 500 to 700 nm>
The visible light absorber used in the present invention is not particularly limited as long as it is a compound having a maximum absorption wavelength of 500 to 700 nm. Visible light absorbers are unnecessary in non-image areas because various compounds contained in the photosensitive layer, including colorants added to impart plate inspection properties, undergo electron transfer reactions by photoexcitation to generate radicals. The occurrence of fog (non-image portion residual color) can be reduced.
As such a visible light absorber, it is particularly preferable to use dyes or pigments as exemplified in the above-mentioned colorants, or water-soluble dyes listed below alone or in combination.

Examples of water-soluble dyes include cationic dyes, reactive dyes, acid dyes, and direct dyes. More specifically, nitroso dyes such as naphthol green B; nitro dyes such as naphthol yellow S and polar yellow brown; Diachron Scarlet RN, Diamira Red B, Diamira Brilliant Red BB, Diamira Brilliant Violet 5R, Diamira Brilliant Red GG, Diamira Brilliant Orange FR, Diamira Brilliant Orange 3R, Diacryl Brilliant Red GTL-N, Diacryl Red GL-N, Diacryl Brilliant Red GRL-N, Victoria Scarlet 3R, Sulfon Acid Blue R, Spramine Red GG, Spramine Red B, Spramine Blue R, Polar Red G, Polar Orange R, Metachrome Red 5G, Metachrome Brilliant Blue B Azo dyes such as Spranol Orange RR and Spranol Brilliant Red; thiazole dyes such as Diacryl Red CS-N, Thiazine Red R, Sirius Scarlet B, and Thioflavin T; Diphenylmethane dyes such as Auramine; Victoria Pure Blue BOH, Crystal Violet, Triphenylmethane dyes such as methyl violet, ethyl violet, spirit blue, acid violet 6B and malachite green; xanthene dyes such as pyronin G, rhodamine S, eosin G, eosin Y, erythrosin, rose bengal B, rhodamine B, rhodamine 3GO; Acridine dyes such as acridine orange 2G and euclicin 2GNX; neutral violet, neutral red, azocarmine G, safranin T Azine dyes such as Wool First Blue BL and Indocyanine B; Oxazine dyes such as Meldraz Blue, Neil Blue A and Garocyanine; Dioxazine dyes such as Sirius Light Blue FFRL and Sirius Light Blue F3GL; Thiazine dyes such as Methylene Blue and Methylene Green B Diacidal blue BR, alizarin direct violet EFF, splatene violet 4BF, alizarin sky blue B, alizarin cyanine green G, carborane green G, alizarin saphirol B, alizarin cyanine green 5G, alizarin brilliant pure blue R, brilliant Anthraquinone dyes such as Alizarin Light Red 4B and Alizarin Uranol 2B; Heliogen Blue SBP, Drazol Fast Bull -Phthalocyanine dyes such as 8GS; cyanine dyes such as diacryl brilliant red 3GN, diacryl brilliant pink GN, diacryl brilliant pink RN, and diacryl brilliant red 6BN; quinoline dyes such as quinoline yellow and spularite yellow GGL It is.
From the viewpoint of the effect of the present invention and physical strength, such a visible light absorber is preferably added in an amount of about 5 to 40% by mass, and 10 to 35% by mass in the oxygen barrier layer coating solution. More preferably, it is most preferable to add 15-25 mass%.

  Any of the above specific light absorbers can be selected according to various purposes as long as they are soluble or uniformly dispersible in the solvent and / or PVA, PVP and the like contained in the oxygen barrier layer coating solution. In the selection, it is necessary that the dye has a main absorption spectrum in a wavelength region other than the emission spectrum of the light source used for forming an image on the photopolymerizable image recording material. The absorbance of the oxygen blocking layer at the wavelength (range) of the emission spectrum needs to be 0.5 or less, preferably 0.1 or less.

  The moisture content of the oxygen barrier layer in the present invention is preferably 7% or less. More preferably, it is 6% or less, More preferably, it is 5% or less. When the moisture content is high, the oxygen barrier layer adheres to the back surface of the aluminum after winding the aluminum during the production of the printing plate, and subsequent peeling becomes difficult, which tends to be a problem in production.

Next, a method for producing the lithographic printing plate precursor according to the present invention will be described.
The method for producing a photosensitive lithographic printing plate precursor according to the present invention is a method for producing a photosensitive lithographic printing plate precursor using the above-described photopolymerizable image recording material according to the present invention, comprising a photopolymerizable layer on a support and After obtaining a lithographic printing plate precursor by providing an oxygen barrier layer, the lithographic printing plate precursor is wound up in a state where the moisture content of the oxygen barrier layer is 7% or less. Hereinafter, a specific process for adjusting the moisture content will be described.

(Moisture content and its control process)
The water content of the oxygen barrier layer according to the present invention is 7% or less, preferably 4 to 7%, from the viewpoint of sensitivity and image formability. More preferably, it is in the range of 4.5 to 6%. In the present specification, the water content means mass% of water contained in the oxygen barrier layer with respect to the total mass of the solid component of the oxygen barrier layer. The moisture content can be measured by, for example, a moisture measuring device based on the Karl Fischer method after peeling off the oxygen blocking layer and dissolving it in a solvent as appropriate.

  All methods for producing a photopolymerizable lithographic printing plate precursor including the step of adjusting the water content are included as the method of the present invention. For example, in the production method of the present invention, after the oxygen blocking layer is applied on the photopolymerizable layer, the support is left in or passed through a humidity control zone having constant temperature and humidity, thereby allowing the constant water content described above. An oxygen barrier layer having a rate can be obtained. As the constant temperature and constant humidity control zone, for example, a constant temperature casing or the like that is provided with air supply and exhaust means and can maintain humidity by this means can be mentioned. The temperature in such a humidity control zone is preferably in the range of 15 to 30 ° C., and the humidity is preferably in the range of 20 to 65%. For example, the oxygen barrier layer may have a desired moisture content by leaving it in the humidity control zone under such conditions, for example, for 30 seconds to 10 minutes, or by passing through the humidity control zone.

  FIG. 3 is a schematic diagram of a process using a humidity control casing, which is an embodiment of the humidity control process in the production method of the present invention. In FIG. 3, the support coated with the photopolymerizable layer and the oxygen blocking layer passes through the first tank for drying, and then passes through the casing at a temperature of 25 ° C. and a humidity of 60% at a constant speed. The rate is adjusted to be constant. The casing of FIG. 3 is connected to the air supply and exhaust means, so that the temperature and humidity in the casing are kept constant. More specifically, such a humidity control casing can be made of, for example, a casing made of a material such as an acrylic plate or aluminum, and the air supply and exhaust means has a casing internal volume of 10 to 10 hours per hour. It can be carried out by a fan or the like having 100 times the air supply and exhaust amount. However, it is known to those skilled in the art that the casing material, size, air supply and exhaust system, etc. can be appropriately designed depending on the set humidity, the type and size of the photopolymerizable lithographic printing plate for humidity control, the scale of the production line, etc. Obviously, it is not limited to these.

  In addition, since the oxygen barrier layer mainly composed of a water-soluble polymer is usually dissolved and applied in water, it is preferable to dry after applying the oxygen barrier layer and before the moisture content adjusting step. Drying is performed, for example, by heating within a temperature range of 90 ° C. to 140 ° C. for 30 seconds to 5 minutes. The humidity control process may be performed subsequent to the drying process, or after the drying process, for example, after a certain period of time due to storage or the like, the humidity control process may be performed. The conditions of the humidity control step can be appropriately changed depending on the moisture content of the support after the drying step, and thus a support having a constant moisture content can be obtained.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
[Examples 1 to 10, Comparative Examples 1 to 3]
(Production of support)
<Aluminum plate>
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.001 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: Containing 0.03% by mass, the balance is prepared by using aluminum and an inevitable impurity aluminum alloy, and after the molten metal treatment and filtration, a 500 mm thick and 1200 mm wide ingot is DC cast. It was produced by the method. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, the temperature was kept constant at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it finished by cold rolling to 0.24 mm in thickness, and obtained the aluminum plate of JIS1050 material. After making this aluminum plate width 1030mm, it used for the surface treatment shown below.

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

(A) Mechanical roughening treatment Using an apparatus as shown in FIG. 4, a suspension of a polishing agent (pumice) having a specific gravity of 1.12 and water is supplied as a polishing slurry to the surface of the aluminum plate. However, a mechanical surface roughening treatment was performed with a rotating roller-like nylon brush. In FIG. 4, 1 is an aluminum plate, 2 and 4 are roller brushes, 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers. The average particle size of the abrasive was 30 μm, and the maximum particle size was 100 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 45 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying using an aqueous solution having a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. / M ² dissolved. Then, water washing by spraying was performed.

(C) Desmutting treatment Desmutting treatment was performed by spraying with a 1% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. The AC power supply waveform is the waveform shown in FIG. 5, the time TP until the current value reaches a peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used, with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 6 was used.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.

(E) Alkali etching treatment An aluminum plate was subjected to an etching treatment by spraying at 32 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass% to dissolve the aluminum plate by 0.50 g / m ^2. The smut component mainly composed of aluminum hydroxide generated when the electrochemical surface roughening process is performed using the alternating current of the previous stage is removed, and the edge portion of the generated pit is melted to smooth the edge portion. I made it. Then, water washing by spraying was performed.

(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(G) Electrochemical surface roughening treatment An electrochemical surface roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 5.0 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform is the waveform shown in FIG. 5, the time TP until the current value reaches a peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used, with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 6 was used.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Then, water washing by spraying was performed.

(H) Alkaline etching treatment The aluminum plate was subjected to an etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was dissolved at 0.10 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.

(I) Desmutting treatment A desmutting treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(J) Anodizing treatment Anodizing treatment was carried out using an anodizing apparatus having a structure shown in FIG. 7 to obtain a lithographic printing plate support. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 170 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 38 ° C. Then, water washing by spraying was performed. The final oxide film amount was 2.7 g / m ² .
The Ra of the support obtained by the above treatment was 0.45.

〔undercoat〕
Next, the following undercoat liquid was applied to this aluminum support with a wire bar, and dried at 90 ° C. for 30 seconds using a hot air drying apparatus. The coating amount after drying was 10 mg / m ² .

<Undercoat liquid>
・ Methyl acrylate: ethyl acrylate: 2-acrylamide-2-
0.1 g of methyl-1-propanesulfonic acid sodium salt in a molar ratio of 70:15:15
・ 2-aminoethylphosphonic acid 0.1g
・ Methanol 50g
・ Ion exchange water 50g

(Photopolymerizable layer)
Next, the following photopolymerizable layer coating solutions (P-1 to P-7, comparative photosensitive solution 1) were prepared and applied to the above-mentioned undercoated aluminum plate using a wire bar. Drying was performed at 122 ° C. for 43.5 seconds with a hot air drying apparatus to form a photopolymerizable layer. The coating amount after drying was 1.4 g / m ² .
<Photopolymerizable layer coating solution>
Infrared absorber (compound described in Table 1) 0.08 g
-Polymerization initiator (compound described in Table 1) 0.30 g
-Sensitization aid (CI-1) 0.15 g
-Polymerizable compound (compound described in Table 1) 1.00 g
-Binder polymer (compound described in Table 1) 1.00 g
・ Coloring agent (Ethyl Violet EV-6Hnaps) 0.04g
・ Fluorine surfactant 0.02g
(Megafuck F-780-F Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 10.4g
・ Methanol 4.83g
・ 10.4 g of 1-methoxy-2-propanol

In Table 1, in the photopolymerizable layer coating liquid P-4, 0.15 g of each of two kinds of initiators (I-2 and I-3) was added.
Infrared absorbers (IR-1 to IR-3) used in the photopolymerizable layer coating solution, sensitizing dyes (comparative dyes) that absorb visible light, polymerization initiators (I-1 to I-7), The structures of the sensitization aid (CI-1), the polymerizable compounds (M-1 to M-3), and the binder polymers (B-1 to B-3) are shown below.

(Oxygen barrier layer)
Next, 6 mass% aqueous solution of the following composition was prepared and the oxygen barrier layer coating liquid (OC-1 to OC-10, comparative OC-1 to comparative OC-3) was obtained. The coating solution was applied to the surface of the photopolymerizable layer with a wire bar so as to have a dry coating mass described in Table 3, and dried at 125 ° C. for 75 seconds using a hot air dryer, and an oxygen blocking layer. Formed.
<Oxygen barrier coating solution>
Polyvinyl alcohol (compound described in Table 2) A part by mass Polyvinylpyrrolidone derivative (compound described in Table 2) B part by mass (provided that A + B = 98 parts by mass, and A / B is PVA / PVP value.)
・ Compounds having an absorption maximum at 250 to 400 nm
(UVA; compounds listed in Table 2, addition amount)
・ Compounds having an absorption maximum at 500 to 700 nm
(VA; compounds listed in Table 2, addition amount)
・ Surfactant (Emalex 710) 2 parts by mass made by Nippon Emulsion ・ Pure water

The compounds in Table 2 are as follows.
(PVA derivative)
PVA105, PVA205 (trade names, all manufactured by Kuraray)

(PVP derivative)
Rubiscor: Rubiscol VA64W (trade name, manufactured by BASF)
VPC: VPC 55 K65W (manufactured by BASF)
Vcap: cap K43E (BASF)
VPI: uvitec VPI55 K18P (manufactured by BASF)

(Compound having an absorption maximum at 250 to 400 nm)
UVA-1: Exemplified Compound 1-2
UVA-2: Exemplified Compound 1-4
UVA-3: Exemplified Compound 1-21

(Compound having an absorption maximum at 500 to 700 nm)
VA-1: Rhodamine B
VA-2: Compound having the following structure VA-3: Pyronin B

Here, the oxygen transmission rate of the oxygen blocking layer when the coating amount (g / m ² ) shown in Table 3 was used was measured under the following conditions. The results are shown in Table 2 as oxygen permeability.
(Measurement of oxygen permeability)
An oxygen blocking layer was applied and dried on the surface of a photographic paper having a thickness of about 200 μm and coated on both sides with a polyethylene having a thickness of about 20 μm, and a sample for measurement was prepared. . The oxygen permeability of the photographic paper measured in advance was about 700 ml / (m ² · day · atom) under the following measurement conditions, and was a value that could be sufficiently ignored when measuring the permeability in the oxygen barrier layer.
Using the sample thus obtained, according to the gas permeability test method described in JIS K7126B and ASTM D3985, oxygen permeation was performed at 25 ° C. and 60% RH using OX-TRAN 2/20 manufactured by Mocon. The rate [ml / (m ² · day · atom)] was measured.

  As described above, lithographic printing plate precursors of Examples 1 to 10 and Comparative Examples 1 to 3 having a photopolymerizable layer and an oxygen blocking layer on a support were obtained. Table 3 below shows which photopolymerizable layer coating solution and oxygen barrier layer coating solution was used.

[Evaluation]
(1) Sensitivity evaluation The obtained planographic printing plate precursors of Examples 1 to 10 and Comparative Examples 1 to 3 were subjected to a Trendsetter 3244VX manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser, with a resolution of 175 lpi and an outer drum rotation speed of 150 rpm. The exposure was performed while changing the log E by 0.15 in the range of 0 to 8 W output. The exposure was performed under conditions of 25 ° C. and 50% RH. After the exposure, the protective layer was removed by washing with tap water, and then developed using LP-1310HII manufactured by Fuji Photo Film Co., Ltd. at 30 ° C. for 12 seconds. The developer used was a 1: 4 water-diluted water of DV-2 manufactured by FUJIFILM Corporation, and the 1: 1 water-diluted solution of GN-2K manufactured by FUJIFILM Corporation was used as the finisher.
Under this condition, assuming that the plate density before processing is 1.0, the exposure amount necessary to obtain an image having a density of 0.9 was used as an index of sensitivity. The value of Example 1 was set as 100 and indicated as a relative value. The results are shown in Table 3.

(2) Safety light safety evaluation <UV-cut white light safety>
The lithographic printing plate precursors of Examples 1 to 10 and Comparative Examples 1 to 3 were subjected to UV-cut white light (FLR 40S-W-NUM made by National Corporation with UV absorbing film) under an environment of 25 ° C. and 50% RH, 400 lux. Then, after the protective layer was removed by rinsing with tap water, development was performed in the same manner as in the development process for the sensitivity evaluation. Subsequently, the non-image area density of the printing plate precursor after development was measured using a Macbeth reflection densitometer RD-918. Further, the lithographic printing plate precursor not exposed to light and handled under a red light was also developed in the same manner, and the non-image area density was measured. In this embodiment, the difference Δfog between the non-image area densities is obtained and used as an index of safelight safety. The smaller the value of Δfog is, the better the safety light safety is, and 0.02 or less is a level that causes no problem in practice. The results are shown in Table 3.

<Yellow light safety>
The lithographic printing plate precursors of Examples 1 to 10 and Comparative Examples 1 to 3 were exposed to yellow light (PS light) and 400 lux for 6 hours in an environment of 25 ° C. and 45% RH, and then washed with tap water. After removing the protective layer, development was performed in the same manner as in the development process for sensitivity evaluation. Subsequently, the non-image area density of the printing plate precursor after development was measured using a Macbeth reflection densitometer RD-918. Further, the lithographic printing plate precursor not exposed to light and handled under a red light was also developed in the same manner, and the non-image area density was measured. In this embodiment, the difference Δfog between the non-image area densities is obtained and used as an index of safelight safety. The smaller the value of Δfog is, the better the safety light safety is, and 0.02 or less is a level that causes no problem in practice. The results are shown in Table 3.

<Safety of white light>
The lithographic printing plate precursors of Examples 1 to 10 and Comparative Examples 1 to 3 were usually white light (OSRAM Neorumi Super FLR40S-W / M / 36, manufactured by Mitsubishi) under an environment of 25 ° C. and 50% RH, 400 After exposure to lux for 1 hour, the protective layer was removed by rinsing with tap water, followed by development in the same manner as in the development process for sensitivity evaluation. Subsequently, the non-image area density of the printing plate precursor after development was measured using a Macbeth reflection densitometer RD-918. Further, the lithographic printing plate precursor not exposed to light and handled under a red light was also developed in the same manner, and the non-image area density was measured. In this embodiment, the difference Δfog between the non-image area densities is obtained and used as an index of safelight safety. The smaller the value of Δfog is, the better the safety light safety is, and 0.02 or less is a level that causes no problem in practice. The results are shown in Table 3.

(3) Evaluation of printing durability An 80% flat screen image with a resolution of 175 lpi was obtained with a Trendsetter 3244VX manufactured by Creo, which was equipped with a water-cooled 40W infrared semiconductor laser on the lithographic printing plate precursors of Examples 1 to 10 and Comparative Examples 1 to 3. In an environment of 25 ° C. and 50% RH, exposure was performed with an output of 8 W, an outer drum rotation speed of 150 rpm, and a plate surface energy of 100 mJ / cm ² . After the exposure, the protective layer was removed by rinsing with tap water, and then developed by the same method as in the developing process of the sensitivity evaluation to obtain a lithographic printing plate.
The obtained lithographic printing plate was printed using a printing press Lithron manufactured by Komori Corporation, and the number of finished sheets was used as an index of printing durability. The results are shown in Table 3.

As is clear from the results in Table 3, the oxygen permeability A, which is a feature of the present invention, is 0.2 ≦ A ≦ 20 (ml / m ² · day) and contains a specific light absorber. The lithographic printing plate precursors of Examples 1 to 10 having a blocking layer were found to be excellent in both safelight safety and printing durability according to the type of the added specific light absorber. On the other hand, when the oxygen permeability A is less than 0.2, the safety light safety is deteriorated (Comparative Example 2), and when the oxygen permeability A is larger than 20, the printing durability is deteriorated (Comparative Example 3). It was found that the level is problematic in practical use. Further, it has been found that when the general oxygen blocking layer contains a specific light absorber, the safety light safety against a normal white light and / or yellow light can be improved.

[Examples 11 to 14, Comparative Example 4]
The oxygen barrier layer is dried in the same manner as in Example 1, and then the humidity control step is performed in the casing shown in FIG. 3 under the conditions shown in Table 4, and Examples 11 to 14 and Comparative Example 4 are performed. A lithographic printing plate precursor was obtained. The water content of the oxygen barrier layer of the obtained lithographic printing plate precursor was measured by the following method. The results are shown in Table 4. Each lithographic printing plate precursor obtained here was wound into a coil shape.

(Measurement method of moisture content of oxygen barrier layer)
A part of the oxygen barrier layer is peeled off, the mass is measured, this is dissolved in anhydrous methanol, and the moisture content in the overcoat layer is measured by a moisture measuring device (KYOTO ELECTRONICS MKC-3) based on the Karl Fischer method. did. The measurement principle of the Karl Fischer method in the above apparatus will be briefly described below.
H ₂ O + I ₂ + SO ₂ + CH ₃ OH + 3RN → 2RN · HI + RN · HSO ₄ CH ₃ (1)
^{2I - → I2 + 2e - (} 2)
Iodine is generated from iodine ions by electrolysis in a generation solution containing iodine ions, and when the generated iodine reacts with water molecules according to the formula (1) and is consumed, it is detected that iodine is consumed at the electrode of the device. Then, iodine is again generated according to the formula (2) by electrolysis. The amount of water in the sample is converted from the amount of electricity required for this electrolysis.

(Peelability evaluation method)
The wound printing plate coil was left to stand in an environment of 30 ° C. and 70% RH for 2 months, and then the sensory evaluation was performed on the ease of peeling when peeling the printing plate from the coil according to the following criteria. The results are shown in Table 4.
Good: Peelable without damaging the printing plate surface. Oxygen barrier layer peels off: Oxygen barrier layer adheres to the back of the aluminum plate as a support during peeling, causing peeling

  As is apparent from Table 4, the planographic printing plate precursors of Examples 11 to 14 obtained by adjusting the moisture content of the oxygen barrier layer within the range of the production method of the present invention were coiled and subjected to a high humidity environment. After being stored for a long time, it was found that the oxygen barrier layer did not peel off and was excellent in production suitability.

It is a schematic block diagram which shows an example of the DRM interference wave measuring apparatus for measuring the dissolution behavior of a photosensitive layer. It is a schematic block diagram which shows an example of the measuring method of the electrostatic capacitance used in evaluating the permeability to the photosensitive layer of a developing solution. It is a schematic diagram which shows one embodiment of the humidity control process in the manufacturing method of this invention. It is a side view which shows the concept of the process of the brush graining used for the mechanical roughening process in preparation of the support body used for the image recording material of this invention. It is a graph which shows an example of the alternating waveform current waveform figure used for the electrochemical roughening process in preparation of the support body used for the image recording material of this invention. It is a side view which shows an example of the radial type cell in the electrochemical roughening process using alternating current in preparation of the support body used for the image recording material of this invention. It is the schematic of the anodizing apparatus used for the anodizing process in preparation of the support body used for the image recording material of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2, 4 Roller-shaped brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller 11 Aluminum plate 12 Radial drum roller 13a, 13b Main electrode 14 Electrolytic process liquid 15 Electrolyte supply port 16 Slit 17 Electrolyte path 18 Auxiliary anode 19a, 19b Thyristor 20 AC power supply 40 Main electrolytic cell 50 Auxiliary anode tank 410 Anodizing device 412 Power supply tank 414 Electrolytic treatment tank 416 Aluminum plate 418, 426 Electrolytic solution 420 Power supply electrode 422, 428 Roller 424 Nip roller 430 Electrolytic electrode 432 Tank wall 434 DC power supply

Claims (5)

A photopolymerizable layer containing (A) a compound having an absorption maximum at 650 to 1300 nm, (B) a polymerization initiator, and (C) a polymerizable compound, and oxygen at 25 ° C. and 1 atm on the support. Permeability A is 0.2 ≦ A ≦ 20 (ml / m ² · day) and contains at least one of a compound having an absorption maximum at 250 to 400 nm and a compound having an absorption maximum at 500 to 700 nm. A photopolymerizable image recording material comprising: an oxygen blocking layer.   The oxygen barrier layer contains polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) or a derivative thereof, and the content ratio [PVA / PVP (or a derivative thereof)] of both is 2 ≦ B ≦ 10 The photopolymerizable image recording material according to claim 1.   The photopolymerizable image recording material according to claim 2, wherein the saponification degree of the PVA is 85% or more.   4. The photopolymerizable image recording material according to any one of claims 1 to 3, wherein the polymerization initiator is a compound capable of generating an aryl radical. A method for producing a photosensitive lithographic printing plate precursor using the photopolymerizable image recording material according to any one of claims 1 to 4,
After obtaining a lithographic printing plate precursor by providing a photopolymerizable layer and an oxygen blocking layer on a support,
A method for producing a photosensitive lithographic printing plate precursor, comprising winding up the lithographic printing plate precursor in a state where the moisture content of the oxygen barrier layer is 7% or less.

Images