JP2002116539A - Original plate of planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative type original plate of a planographic printing plate which can record with an IR laser, does not require heating after imagewise exposure, has high sensitivity, suppresses a sensitivity change with age, is excellent in shelf stability and adaptable to a heat mode. SOLUTION: The original plate has a photosensitive layer containing (A) a polymerization initiator having an onium salt structure, (B) a photothermal converting agent, (C) a compound having a polymerizable unsaturated group and (D) a borate compound of the formula Ar4B-M+ and capable of recording with an IR laser on the base. In the formula, M+ is a monovalent cation and each Ar is an aromatic group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor which can be written with an infrared laser, and more particularly, to a lithographic printing plate precursor having a high sensitivity and having a negative recording layer in which a decrease in sensitivity with time is suppressed. About.

[0002]

2. Description of the Related Art In recent years, the development of lasers has been remarkable. In particular, solid-state lasers and semiconductor lasers having a light-emitting region from the near infrared to the infrared have been increasing in output and miniaturization. Therefore, these lasers are very useful as an exposure light source when making a plate directly from digital data of a computer or the like. Using an infrared laser having an emission region in the infrared region as an exposure light source, a negative type lithographic printing plate material for an infrared laser, an infrared absorber, and a polymerization initiator that generates radicals by light or heat,
A lithographic printing plate material having a photosensitive layer containing a polymerizable compound.

As such a negative type image recording material, for example, a recording material comprising an infrared absorber, an acid generator, a resol resin and a novolak resin is disclosed in US Pat.
No. 699. However, such a negative type image recording material requires a heat treatment of heating at 140 to 200 ° C. for about 50 to 120 seconds after laser exposure in order to form an image. It required extensive equipment and energy.

Japanese Patent Publication No. 7-103171 discloses a heat treatment after imagewise exposure comprising a cyanine dye having a specific structure, an iodonium salt and an addition-polymerizable compound having an ethylenically unsaturated double bond. Although a recording material which is not required is described, this image recording material has a problem that polymerization is inhibited by oxygen in the air at the time of polymerization reaction and sensitivity is insufficient. Further, JP-A-8-10
No. 8621 describes an image recording medium containing an organic oxide or an azobisnitrile compound which is a general-purpose thermal polymerization initiator and a thermopolymerizable resin, and all have an image recording sensitivity of 200 J / cm ^2. As described above, at present, practically required high sensitivity has not been achieved, for example, a preheat treatment at the time of exposure is required to improve sensitivity. On the other hand, in order to improve sensitivity, as described in JP-A-2000-98603, when a borate compound having a high photopolymerization initiation ability itself is used as an initiator, it is handled for a long time under white light. However, there is a concern that an undesired curing reaction may proceed when the composition is stored or stored for a long period of time, and the sensitivity to exposure may be degraded.

[0005]

Accordingly, an object of the present invention is to record directly using digital data from a computer or the like by recording using a solid-state laser or a semiconductor laser that emits infrared light. It is an object of the present invention to provide a negative type lithographic printing plate precursor which does not require a heat treatment, has high sensitivity, suppresses fluctuations in sensitivity over time, and has excellent storage stability.

[0006]

Means for Solving the Problems The present inventor paid attention to the components of the negative-type image recording material, and as a result of intensive studies, as a result, used a highly sensitive initiator having an onium salt structure together with a stable borate additive. Thus, they have found that both high sensitivity and improved storage stability can be achieved, and have completed the present invention.
That is, the lithographic printing plate precursor according to the present invention comprises (A)
A polymerization initiator having an onium salt structure, (B) a photothermal conversion agent, (C) a compound having a polymerizable unsaturated group, and
(D) A photosensitive layer containing a borate compound represented by the following general formula (1) and recordable by an infrared laser. The photosensitive layer preferably further contains (E) a binder for the purpose of improving the film properties.

[General formula (1)] Ar ₄ B ^- M ^{+ wherein} M ⁺ is a monovalent cation and Ar is each independently
Represents an aromatic group.

Although the function of the present invention is not clear, since it contains an electron-donating borate compound, the decomposition of the onium salt as a thermal radical generator is promoted, and the polymerization of the radical polymerizable compound proceeds rapidly. It is considered that the sensitivity is improved. Another mechanism for increasing the sensitivity is that the borate compound reduces phenyl cations and the like that are expected to be generated by the decomposition of the onium salt that is the polymerization initiator, and increases the effective radicals that contribute to the polymerization reaction. Can be Further, since the (D) borate compound as an additive of the present invention has four aromatic groups, a borate compound having a high photopolymerization initiation ability itself such as a triarylalkyl borate or a diaryldialkyl borate can be used. Unlike the case where the photosensitive material is used, it is possible to suppress the progress (fogging) of the curing reaction in the non-image area when the photosensitive material is handled under a white fluorescent lamp and the deterioration of the image forming property when the photosensitive material is stored for a long time. .

In the present invention, "corresponding to heat mode" means that recording by heat mode exposure is possible. The definition of the heat mode exposure in the present invention will be described in detail. Hans-Joachim Tim
pe, IS & Ts NIP 15: 1999 Inte
rational Conference on D
digital printing technology
ies. P. As described in 209, a photoabsorbing substance (for example, a dye) is photoexcited in a photoreceptor material, and undergoes a chemical or physical change to form a chemical or physical change from the photoexcitation of the photoabsorbing substance forming an image. It is known that there are roughly two modes in the above processes. One is that the photoexcited light absorbing substance is deactivated by some photochemical interaction (eg, energy transfer, electron transfer) with other reactants in the photosensitive material,
As a result, a so-called photon mode in which the activated reactant causes a chemical or physical change required for the above-described image formation, and the other is that the photoexcited light absorbing substance generates heat and deactivates, and the heat is lost. This is a so-called heat mode in which a reactant causes a chemical or physical change required for image formation using the above-described method. In addition, there are special modes such as ablation in which substances are explosively scattered by the energy of light locally collected and multiphoton absorption in which one molecule absorbs many photons at a time, but these modes are omitted here.

[0010] The exposure processes utilizing the above-described modes are called photon mode exposure and heat mode exposure. The technical difference between photon mode exposure and heat mode exposure is whether or not the energy amount of several photons to be exposed can be added to the energy amount of the target reaction.
For example, consider a case where a certain reaction is caused by using n photons. In photon mode exposure, photochemical interaction is used, so that the energy of one photon cannot be added together due to the requirement of the law of conservation of quantum energy and momentum. That is, in order to cause a certain reaction, the relationship of “energy amount of one photon ≧ energy amount of reaction” is necessary. On the other hand, in heat mode exposure, heat is generated after light excitation, and light energy is converted into heat and used, so that the amount of energy can be added. Therefore, the relationship “energy amount of n photons ≧ energy amount of reaction” is sufficient. However, this energy addition is restricted by thermal diffusion. That is, if the next photoexcitation-deactivation process occurs and heat is generated before the heat escapes from the exposed portion (reaction point) of interest by thermal diffusion, the heat is reliably accumulated and added, and the temperature rises in that portion. Leads to. However, when the next heat is generated slowly, the heat escapes and is not accumulated. In other words, in the heat mode exposure, the result is different between the case of irradiating a high energy light for a short time and the case of irradiating a low energy light for a long time even at the same total exposure energy. It becomes advantageous for accumulation of.

Of course, in the photon mode exposure, a similar phenomenon may occur due to the influence of the diffusion of the subsequent reactive species, but basically, such a phenomenon does not occur. That is, in terms of the characteristics of the photosensitive material, in the photon mode, the intrinsic sensitivity of the photosensitive material (the energy required for the reaction required for image formation) is compared with the exposure power density (w / cm ² ) (= energy density per unit time). Amount) is constant, but in the heat mode, the intrinsic sensitivity of the photosensitive material increases with respect to the exposure power density. Therefore, if the exposure time is fixed such that the productivity necessary for practical use as an image recording material can be maintained, the photon mode exposure usually has a high sensitivity of about 0.1 mJ / cm ² when comparing the modes. Reaction can be achieved at any low exposure, although
The problem of low-exposure fog in unexposed areas is likely to occur. On the other hand, in the heat mode exposure, a reaction does not occur unless the exposure amount exceeds a certain value, and usually about 50 mJ / cm ² is required in relation to the thermal stability of the photosensitive material. Is avoided. In fact, in heat mode exposure, the exposure power density on the plate surface of the photosensitive material is 500
0 w / cm ² or more, preferably 10,000
w / cm ² or more is required. However, although not described in detail here, when a high power density laser of 5.0 × 10 ⁵ / cm ² or more is used, ablation occurs, which is not preferable because of problems such as soiling the light source.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [(A) Polymerization initiator having an onium salt structure (hereinafter, simply referred to as onium salt)] The polymerization initiator in the present invention is a compound which generates a radical by thermal energy and has a polymerizable unsaturated group. Refers to a compound that initiates and promotes the polymerization of As the polymerization initiator according to the present invention, a known thermal polymerization initiator or a compound having a bond having a small bond dissociation energy can be selected and used.From the viewpoint of sensitivity, the onium salt structure described below is used. Are preferred. Examples of the onium salt suitably used in the present invention include known diazonium salts, iodonium salts, sulfonium salts, ammonium salts, pyridinium salts and the like, among which triarylsulfonium,
Alternatively, a diaryl iodonium sulfonate, a carboxylate, BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ or the like is preferable. The sulfonium salts and iodonium salts having a carboxylate as a counter anion described above can be used. In the present invention, these onium salts function not as an acid generator but as a radical polymerization initiator. Examples of the onium salt that can be used in the present invention include onium salts represented by the following general formulas (III) to (V).

[0013]

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In the formula (III), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms which may have a substituent. When the aryl group has a substituent, preferred 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 a 12 or less carbon atom. Aryloxy groups. Z ^11- represents a counter ion selected from the group consisting of a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, and is preferably a perchlorate ion or a hexafluorophosphate. And arylsulfonate ions. In the formula (IV), Ar ²¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred 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, an aryloxy group having 12 or less carbon atoms,
Examples include an alkylamino group having 12 or less carbon atoms, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, and a diarylamino group having 12 or less carbon atoms. Z ^{21 -} represents a counter ion of the same meaning as Z ^11-. In the formula (V), R ³¹ , R ³² and R
³³ is the same or different, and represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, and a 1-carbon atom.
Examples include an alkoxy group having 2 or less or an aryloxy group having 12 or less carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

In the present invention, an onium salt ([OI-1]) represented by the general formula (III) which can be suitably used:
To [OI-10]), onium salts represented by the general formula (IV) ([ON-1] to [ON-5]), and the general formula (V)
Onium salts represented by the formula ([OS-1] to [OS-6])
Specific examples are described below.

[0016]

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[0017]

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[0018]

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[0019]

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The onium salt used in the present invention is
Preferably, the maximum absorption wavelength is 400 nm or less,
Further, the thickness is preferably 360 nm or less. By setting the absorption wavelength in the ultraviolet region, the image recording material can be handled under a white light.

These onium salts are used in an amount of 0.1 to 40% by weight, preferably 0.5 to 3% by weight, based on the total solid content of the image recording material.
0% by weight, particularly preferably 1 to 20% by weight, can be added to the image recording material. If the addition amount is less than 0.1% by weight, the sensitivity is lowered, and if it exceeds 40% by weight, the non-image area is stained during printing. One of these onium salts may be used alone, or two or more thereof may be used in combination. Further, these onium salts may be added to the same layer as other components, or another layer may be provided and added thereto.

[(D) Borate compound represented by the general formula (1)] As a characteristic additive in the photosensitive layer of the lithographic printing plate precursor according to the invention, an aromatic group represented by the following general formula (1) And a borate compound having four. Such a borate compound is appropriately referred to as a tetraaryl borate in this specification. [Formula (1)] Ar ₄ B ^- M ⁺ wherein, each independently four Ar,. 6 to carbon atoms
Represents 18 aromatic groups. These aromatic groups may have one or more substituents. Examples of preferred substituents include a halogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, Examples include an aryl group, an alkenyl group, a carbonyl group, a carboxyl group, an amide group, an acetyl group, an ether group, a thioether group, an ester group, an amino group, or a combination of two or more of these. Among these aromatic groups, from the viewpoint of stability, an unsubstituted aromatic group, or a group having a halogen atom or a haloalkyl group as a substituent is preferable, and more preferably, a fluorine atom is contained in one molecule. A borate compound having four or more or a substituent having four or more fluorinated alkyl groups is exemplified.

Preferred examples of the cation M ⁺ include an alkali metal ion, Li ⁺ , and “Onium
ions ”(A. Olha, Kennneth K. Laali, Qi Wang, GK
Published by A Wiley-Intorscience Pub, Surya Prakash et al.
ilcation) azonium salts (ammonium salts,
Diazonium salts), oxonium salts, phosphonium salts,
Sulfonium salts, halonium salts, siliconium salts and the like, or pyridinium salts and cation portions of iodonium salts and the like, from the viewpoint of sensitivity, azonium,
Pyridinium and alkali metal ions are more preferred.

Preferred specific examples of the borate compound represented by the general formula (1) [(D-1) to (D-28)] are shown below, but the present invention is not limited thereto.

[0025]

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[0026]

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[0027]

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These borate compounds may be used alone or in combination of two or more. The addition amount is 0.1 to 30% by weight based on the total solid content of the image recording material,
Preferably from 0.5 to 25% by weight, particularly preferably from 1 to 2% by weight.
0% by weight can be added. The amount added is 0.
If it is less than 1% by weight, the effect of improving sensitivity becomes insufficient, and if it exceeds 30% by weight, there is a concern about stability.

[(B) Photothermal Conversion Agent] In the present invention, the photothermal conversion agent contained in the photosensitive layer is not particularly limited as long as it has a photothermal conversion function of generating heat by irradiation with an infrared laser. So-called infrared absorbers can be used. The photothermal conversion agent used in the present invention is
An infrared absorbing dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm is preferable.

As the dye, commercially available dyes and known dyes described in literatures such as "Dye Handbook" (edited by the Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes Is mentioned.

Preferred dyes include, for example, those described in
Cyanine dyes described in JP-A-8-125246, JP-A-59-84356, JP-A-59-202829 and JP-A-60-78787;
No. 96, JP-A-58-181690, JP-A-58-1
No. 94595, etc., methine dyes described in
8-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996,
Naphthoquinone dyes described in JP-A-60-52940 and JP-A-60-63744;
Squarylium dyes described in No. 12792, etc.,
Cyanine dyes described in British Patent 434,875 and the like can be mentioned.

Further, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also preferable. Pyrylium salt, JP-A-57-142645
No. (U.S. Pat. No. 4,327,169), trimethinethiapyrylium salts described in JP-A-58-181051, 58-220143, 59-41363, and 59.
Nos. -84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranyl compounds, cyanine dyes described in JP-A-59-216146, pentamethinethiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fairness 5-13
Pyrylium compounds disclosed in JP-A-514 and JP-A-5-19702 are also preferably used.

Further, as another preferred example of the dye, US Pat. No. 4,756,993 discloses a compound represented by the formula (I):
Near-infrared absorbing dyes described as (II) can be mentioned.

Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Further, a cyanine dye is preferable, and a cyanine dye represented by the following general formula (I) is most preferable.

[0035]

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In the general formula (I), X ¹ is a halogen atom,
-NPh _2, or an X ² -L ^1. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ has 1 to 1 carbon atoms.
And 12 hydrocarbon groups. R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photosensitive layer coating solution, R ¹ and R ² are preferably a hydrocarbon group having 2 or more carbon atoms.
It is particularly preferred that R ¹ and R ² are bonded to each other to form a 5- or 6-membered ring.

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. Preferred examples of the substituent include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. 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 represent 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,
Examples include a carboxyl group and a sulfo group. R ⁵ , R ⁶ , R
⁷ and R ⁸ may be the same or different,
It represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the viewpoint of availability of raw materials, a hydrogen atom is preferable. Z ^1- represents a counter anion. However, when any of R ^{1 to} R ⁸ is substituted with a sulfo group, Z ¹⁻ is not necessary. Preferred Z ¹⁻ is, from the storage stability of the photosensitive layer coating solution, a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion,
And sulfonate ions, particularly preferably perchlorate ion, hexafluorophosphate ion and arylsulfonate ion.

In the present invention, specific examples of the cyanine dye represented by the general formula (I) which can be suitably used include paragraph [0] of Japanese Patent Application No. 11-310623.
017] to [0019], Japanese Patent Application No. 2000-224031.
Nos. [0012] to [0038] in the specification, and paragraph [001] in the specification of Japanese Patent Application No. 2000-21147.
2] to [0023].

Examples of the pigment used as a photothermal conversion agent in the present invention include commercially available pigments and Color Index (CI) Handbook, "Saishin Pigment Handbook" (edited by Japan Pigment Technical Association, published in 1977), "Saishin Pigment" Application Technology ”(CMC
Publishing, 1986) and "Printing Ink Technology", CMC Publishing, 1984).

The pigments include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer-bound dyes. Specifically, insoluble azo pigments, azo lake pigments, condensation azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyeing lake pigments,
Azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used.
Preferred among these pigments is carbon black.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. Examples of the surface treatment include a method of surface coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (eg, a silane coupling agent, an epoxy compound, a polyisocyanate, etc.) to the pigment surface. Can be considered. The above surface treatment methods are described in "Properties and Applications of Metallic Soap" (Koshobo),
It is described in "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986).

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.
Is preferably within the range. Pigment particle size 0.01μ
When it is less than m, it is not preferable in terms of stability of the dispersion in the coating solution of the image-sensitive layer, and when it exceeds 10 μm, it is not preferable in terms of uniformity of the image-sensitive layer.

As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. For details, refer to “Latest Pigment Application Technology” (CMC Publishing, 1
986).

These light-to-heat converting agents may be added to the same layer as other components, or may be added to another layer provided. However, when a negative type image forming material is prepared, The optical density of the photosensitive layer at the absorption maximum in the wavelength range of 760 nm to 1200 nm is preferably between 0.1 and 3.0. Outside of this range, sensitivity tends to decrease. Since the optical density is determined by the amount of the infrared absorbing agent added and the thickness of the recording layer, a predetermined optical density can be obtained by controlling both conditions. The optical density of the recording layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a coating layer after drying is formed on a recording layer having a thickness appropriately determined in a range required as a lithographic printing plate, and a transmission type optical densitometer is used. Examples include a method of measuring, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.

[(C) Compound having a polymerizable unsaturated group] The compound having a polymerizable unsaturated group used in the present invention is an addition polymerizable compound having at least one ethylenically unsaturated double bond. And is preferably selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. Such compounds are widely known in the industrial field, and they can be used in the present invention without any particular limitation. These are, for example, monomers, prepolymers, ie dimers,
Includes those having chemical forms such as trimers and oligomers, or mixtures thereof, and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters and amides thereof, and are preferred. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy,
A dehydration condensation product with a monofunctional or polyfunctional carboxylic acid is also preferably used.

Further, unsaturated carboxylic acid esters and amides having an electrophilic substituent such as an isocyanato group or an epoxy group, and monofunctional or polyfunctional alcohols,
Amines, addition products with thiols, halogen groups,
Substitution products of unsaturated carboxylic acid esters and amides having a leaving substituent such as a tosyloxy group and the like with monofunctional or polyfunctional alcohols, amines and thiols are also suitable. As another example, it is also possible to use a group of compounds in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene, vinyl ether or the like.

Specific examples of the ester monomer of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3.
-Butanediol diacrylate, 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, SO Bito one Le pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 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-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

As the crotonic acid ester, ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like. Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, and JP-A-59-5240. 59-524
1, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Further, the above-mentioned ester monomers can be used as a mixture.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylenebis-acrylamide, methylenebis-methacrylamide, 1,6-hexamethylenebis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like. Examples of other preferred amide-based monomers include those having a cyclohexylene structure described in JP-B-54-21726.

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups in one molecule and a hydroxyl-containing vinyl monomer represented by the following general formula (2) added to one molecule. Examples include vinyl urethane compounds containing two or more polymerizable vinyl groups.

[0055]

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In the general formula (2), R and R ′ represent H or CH ₃ . Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and
Urethane compounds having an ethylene oxide skeleton described in JP-A-8-49860, JP-B-56-17654, JP-B-62-39417, and JP-B-62-39418 are also suitable.

Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909 and JP-A-1-105238. Can obtain a photosensitive composition having a very high photosensitive speed.

Another example is described in JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in each publication. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Further, the Journal of the Adhesion Society of Japan, vol. 20, no. 7, pages 300 to 308 (1
984) as photocurable monomers and oligomers.

Regarding these addition polymerizable compounds, what kind of structure is used, whether they are used alone or in combination,
Details of the method of use, such as the amount of addition, can be arbitrarily set in accordance with the final performance design of the light-sensitive material. For example, it is selected from the following viewpoints. From the viewpoint of the photosensitive speed, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or more functional structure is preferable. In order to increase the strength of the image area, that is, the cured film, those having three or more functional groups are preferable, and further, different functional numbers and different polymerizable groups (for example, acrylates, methacrylates, styrene compounds, vinyl ethers) It is also effective to adjust both the photosensitivity and the intensity by using the compound (1) in combination. A compound having a large molecular weight or a compound having a high hydrophobicity is excellent in photosensitive speed and film strength, but may not be preferable in terms of developing speed and precipitation in a developing solution.

Further, compatibility with other components (eg, a binder polymer, an initiator, a colorant, etc.) in the photosensitive composition,
The selection and use of the addition polymerization compound is also an important factor for the dispersibility. For example, the use of a low-purity compound or the combination of two or more compounds may improve the compatibility. In the case of a lithographic printing plate precursor, a specific structure may be selected for the purpose of improving the adhesiveness of a support, an overcoat layer, and the like described below. Regarding the compounding ratio of the addition polymerizable compound in the photosensitive composition, the larger the proportion, the more advantageous in sensitivity. However, if the proportion is too large, undesired phase separation may occur or the production of the photosensitive composition due to the stickiness may occur. Process problems (for example, improper production due to transfer of photosensitive material components or adhesion)
In the case of a lithographic printing plate precursor, problems such as precipitation from a developer may occur. From these viewpoints, the preferred compounding ratio is often 5 to 8 based on all components of the composition.
0% by weight, preferably 25 to 75% by weight. Also,
These may be used alone or in combination of two or more. In addition, the method of using the addition polymerizable compound can be arbitrarily selected from the viewpoints of the degree of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface tackiness, etc. Depending on the case, a layer structure and a coating method such as undercoating and overcoating may be performed.

[(E) Binder] In the lithographic printing plate precursor according to the invention, it is preferable to further add a binder polymer to the photosensitive layer for the purpose of improving film properties. As the binder used here, a water-insoluble and aqueous alkaline solution-soluble linear organic high molecular polymer is preferable. As such a "linear organic high molecular polymer", any known polymer can be selected and used, but water or a weak alkali which enables water development or weak alkaline water development is preferable. A water-soluble or swellable linear organic high molecular polymer is selected. The linear organic high molecular polymer is selected and used not only as a film forming agent of the composition but also as a water, weakly alkaline water or organic solvent developing agent. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such linear organic high-molecular polymers include addition polymers having a carboxylic acid group in a side chain, for example, JP-A-59-44615, JP-B-54-3.
4327, JP-B-58-12577, JP-B-54-
25957, JP-A-54-92723, JP-A-59-59723
-53836 and JP-A-59-71048, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, There are partially esterified maleic acid copolymers and the like. 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 an addition polymer having a hydroxyl group are useful.

In particular, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / Other addition-polymerizable vinyl monomers as needed) copolymer,
It is suitable because it has an excellent balance of film strength, sensitivity and developability.

In addition, Japanese Patent Publication No. Hei 7-2004,
JP-A-120041, JP-B-7-120042, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1-271174,
The urethane-based binder polymer containing an acid group described in Japanese Patent Application No. 10-116232 is very excellent in strength, and is advantageous in terms of printing durability and low exposure suitability.
Further, a binder having an amide group described in JP-A-11-171907 is suitable because it has excellent developability and film strength.

Further, as the water-soluble linear organic polymer, polyvinyl pyrrolidone, polyethylene oxide and the like are useful. 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. These linear organic high molecular polymers can be incorporated in any amount into the entire composition. However, if it exceeds 90% by weight, no favorable result is obtained in view of the strength of the formed image and the like. Preferably 30 to 85
% By weight. The weight ratio of the photopolymerizable compound having an ethylenically unsaturated double bond and the linear organic high molecular weight polymer is preferably in the range of 1/9 to 7/3.

The binder polymer of the present invention is substantially insoluble in water and soluble in an aqueous alkali solution. For this reason, an organic solvent which is not environmentally unfavorable is not used or the amount used is extremely small as a developer.
The acid value (acid content per gram of polymer expressed by chemical equivalent number) and molecular weight of such a binder polymer are appropriately selected from the viewpoint of image strength and developability. The preferred acid value is 0.4 to 3.0 meq / g, and the preferred molecular weight is in the range of 3,000 to 500,000, more preferably the acid value is in the range of 0.6 to 2.0, and the molecular weight is in the range of 10,000 to 300,000. It is.

[(F) Other Components] In the photosensitive composition of the present invention, other components suitable for its use, production method and the like can be appropriately added. Hereinafter, preferred additives will be exemplified. (F-1) Co-sensitizer The sensitivity can be further improved by using a certain additive (hereinafter referred to as a co-sensitizer). Although their mechanism of action is not clear, most are thought to be based on the following chemical processes. That is, the co-sensitizer reacts with a photoreaction initiated by the thermal polymerization initiator and various intermediate active species (radicals, cations) generated in the course of the subsequent addition polymerization reaction to generate a new active radical. It is estimated that These are largely (a) those that can be reduced to form active radicals, (b) those that can be oxidized to form active radicals, and (c) those that react with less active radicals and are more active radicals. Or acting as a chain transfer agent, but there is often no myth as to which of these compounds each belongs to.

(A) Compound that generates an active radical upon being reduced Compound having a carbon-halogen bond: It is considered that the carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-triazines, trihalomethyloxadiazoles and the like can be suitably used. Compound having a nitrogen-nitrogen bond: It is considered that the nitrogen-nitrogen bond is reductively cleaved to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used. Compound having an oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is reductively cleaved to generate an active radical. Specifically, for example, organic peroxides and the like are preferably used. Onium compound: a carbon-hetero bond or an oxygen-
It is thought that the nitrogen bond is cleaved to generate an active radical. Specifically, for example, diaryliodonium salts,
Triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used. Ferrocene, iron arene complexes: can generate active radicals reductively.

(B) Compound which is oxidized to generate an active radical Alkyl ate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to generate an active radical. Specifically, for example, triarylalkyl borates are preferably used. Alkylamine compound: It is considered that the CX bond on carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical. X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group, or the like.
Specific examples include ethanolamines, N-phenylglycines, N-trimethylsilylmethylanilines and the like. Sulfur- and tin-containing compounds: Compounds in which the nitrogen atom of the above-mentioned amines is replaced with a sulfur atom or a tin atom can generate an active radical by the same action. Compounds having an SS bond are also known to be sensitized by SS cleavage.

Α-Substituted methylcarbonyl compound: An active radical can be generated by cleavage of a bond between carbonyl and α carbon by oxidation. In addition, those obtained by converting carbonyl to oxime ether also show the same action. In particular,
2-alkyl-1- [4- (alkylthio) phenyl]
-2-morpholinopronones-1 and oxime ethers obtained by reacting these with hydroxyamines and then etherifying N-OH. Sulfinates: Active radicals can be generated reductively. Specific examples include sodium arylsulfin sodium.

(C) Compounds which react with radicals to convert them into highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, GeH in the molecule are used. These can generate a radical by donating hydrogen to a low-activity radical species, or can generate a radical by being oxidized and then deprotonated. Specific examples include 2-mercaptobenzimidazoles.

More specific examples of these co-sensitizers are described in, for example, JP-A-9-236913 as additives for the purpose of improving sensitivity. Can also be applied.

(F-2) Polymerization Inhibitor In the present invention, in addition to the above basic components, there is no need for a compound having an ethylenically unsaturated double bond which can be polymerized during the production or storage of the photosensitive composition. It is desirable to add a small amount of a thermal polymerization inhibitor to prevent the thermal polymerization. Suitable thermal polymerization inhibitors include hydroquinone, p
-Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4- Methyl-
6-t-butylphenol), cerium N-nitrosophenylhydroxyamine, and the like. The amount of the thermal polymerization inhibitor added is about 0.01 to the weight of the whole composition.
% By weight to about 5% by weight is preferred. In addition, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition by oxygen, and when used as a lithographic printing plate precursor, after application to a support or the like, During the drying process, it may be unevenly distributed on the surface of the photosensitive layer. The amount of the higher fatty acid derivative to be added ranges from about 0.5% by weight to about 10% by weight of the total composition.
% By weight is preferred.

(F-3) Colorant, etc. Further, a dye or pigment may be added for the purpose of coloring the photosensitive layer. As a result, it is possible to improve the so-called plate inspection, such as the visibility of the printing plate after plate making and the suitability for an image density measuring device. As a coloring agent, a pigment is particularly preferable because many dyes lower the sensitivity of the photopolymerizable photosensitive layer. Specific examples include phthalocyanine pigments, azo pigments, carbon black, pigments such as titanium oxide, ethyl violet,
There are dyes such as crystal violet, azo dyes, anthraquinone dyes and cyanine dyes. Dyes and pigments are added in an amount of about 0.5% to about 5% by weight of the total composition.
Is preferred.

(F-4) Other Additives The photosensitive layer according to the present invention may further include an inorganic filler, other plasticizers, and an ink deposit on the surface of the photosensitive layer in order to improve the physical properties of the cured film. Known additives such as a sensitizer that can be improved may be added.

Examples of the plasticizer include dioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin and the like. A binder was used. In this case, it can be added in an amount of 10% by weight or less based on the total weight of the compound having an ethylenically unsaturated double bond and the binder.

Further, a UV initiator, a ripening crosslinking agent, and the like for enhancing the effect of heating and exposure after development for the purpose of improving the film strength (printing durability) described later can also be added. In addition, it is possible to provide an additive and an intermediate layer for improving the adhesion between the photosensitive layer and the support and for improving the development and removability of the unexposed photosensitive layer. For example, a compound having a diazonium structure or a phosphone compound, such as a compound having a relatively strong interaction with the substrate or an undercoat, the adhesion is improved,
The printing durability can be increased, while the addition or undercoating of a hydrophilic polymer such as polyacrylic acid or polysulfonic acid improves the developability of the non-image area and improves the stain resistance.

Next, other layers optionally provided in the lithographic printing plate precursor according to the invention will be described. [Protective layer] The lithographic printing plate precursor according to the invention is usually subjected to exposure in the air.
It is preferable to provide a protective layer. The protective layer prevents low-molecular compounds such as oxygen and basic substances present in the atmosphere that inhibit the image forming reaction caused by exposure in the photosensitive layer from being mixed into the photosensitive layer, and enables exposure in the atmosphere. I do. Therefore, the desired properties of such a protective layer is that the permeability of low molecular compounds such as oxygen is low, and further, the transparency of light used for exposure is good, and the adhesion with the photosensitive layer is excellent. In addition, it is desirable that it can be easily removed in a developing step after exposure.

Such a device for the protective layer has been conventionally devised, and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, it is preferable to use a water-soluble polymer compound having relatively excellent crystallinity. Although water-soluble polymers such as acrylic acid are known, use of polyvinyl alcohol as a 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 protective layer may be partially substituted with an ester, an ether, or an acetal as long as it contains an unsubstituted vinyl alcohol unit for obtaining necessary oxygen barrier properties and water solubility. Similarly, a part thereof may have another copolymer component.

Specific examples of polyvinyl alcohol include 7
1-100% hydrolyzed, molecular weight 300-240
A range of 0 can be given. Specifically, Kuraray's PVA-105, PVA-110, PVA
A-117, PVA-117H, PVA-120, PV
A-124, PVA-124H, PVA-CS, PVA
-CST, PVA-HC, PVA-203, PVA-2
04, PVA-205, PVA-210, PVA-21
7, PVA-220, PVA-224, PVA-217
EE, PVA-217E, PVA-220E, PVA-
224E, PVA-405, PVA-420, PVA-
613 and L-8.

The components of the protective layer (selection of PVA, use of additives), coating amount, etc. are selected in consideration of fogging properties, adhesion and scratch resistance in addition to oxygen blocking properties and development removability. Generally, the higher the hydrolysis rate of the PVA used (the higher the content of unsubstituted vinyl alcohol units in the protective layer) and the thicker 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 an unnecessary polymerization reaction occurs during production or raw storage, and unnecessary fogging and thickening of an image occur during image exposure. Further, the adhesion to the image area and the scratch resistance are also extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on a lipophilic polymer layer, film peeling due to insufficient adhesive force is likely to occur, and the peeled portion causes defects such as poor film curing due to inhibition of oxygen polymerization.

On the other hand, various proposals have been made to improve the adhesiveness between these two layers. For example, US Patent No. 2
No. 92,501 and U.S. Pat. No. 44,563, an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer or the like is mixed at 20 to 60% by weight in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by laminating on a polymer layer. Any of these known techniques can be applied to the protective layer in the present invention. Regarding the method of applying such a protective layer,
For example, U.S. Pat. No. 3,458,311;
No. 49729.

Further, other functions can be imparted to the protective layer. For example, it has excellent light transmittance of the wavelength used for exposure,
Addition of a coloring agent (such as a water-soluble dye) that can efficiently absorb light having a wavelength that does not contribute to image formation can further enhance the suitability for safelight without lowering the sensitivity.

[Support] The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like material.
Paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate) laminated with polyethylene, polypropylene, polystyrene, etc. Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.). These are single component sheets such as resin films and metal plates,
The laminate may be a laminate of two or more materials, for example, such as the above-described metal-laminated or vapor-deposited paper or plastic film, or a laminated sheet of different types of plastic films.

As the support, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate which has good dimensional stability and is relatively inexpensive is particularly preferable. Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. The content of foreign elements in the alloy is at most 10% by weight
It is as follows. Particularly preferred aluminum in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate,
About 0.1 to 0.6 mm, preferably 0.15 to
It is 0.4 mm, particularly preferably 0.2 to 0.3 mm.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with a surfactant, an organic solvent or an aqueous alkali solution or the like is performed to remove the rolling oil on the surface. The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. It is performed by the method of causing. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. In addition, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Also,
As disclosed in JP-A-54-63902, a method in which both are combined can also be used. The aluminum plate thus roughened can be subjected to an anodic oxidation treatment through alkali etching treatment and neutralization treatment, if desired, in order to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used, and generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The anodizing treatment conditions vary depending on the electrolyte to be used and cannot be specified unconditionally.
Current density 5 to 60 A / dm ^2, voltage 1 to 100 V, which is an electrolyzing time of 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide coating is less than 1.0 g / m ² , the printing durability is insufficient, and the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing. "Scratch dirt" is likely to occur. Although such anodizing treatment is performed on a surface used for printing of the support of lithographic printing plates, the back around the electric lines of force, 0.01 to 3 g / m ² on the back surface
Is generally formed.

The hydrophilizing treatment of the support surface is performed after the above-described anodic oxidation treatment, and a conventionally known treatment method is used. As such a hydrophilic treatment,
U.S. Pat. Nos. 2,714,066 and 3,181,4
No. 61, No. 3,280,734 and No. 3,902,7
No. 34 discloses an alkali metal silicate (for example, an aqueous solution of sodium silicate). In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, Japanese Patent Publication No. 36-22
No. 063, and potassium fluoride zirconate disclosed in U.S. Pat. Nos. 3,276,868 and 4,15.
For example, a method of treating with polyvinyl phosphonic acid as disclosed in Japanese Patent Nos. 3,461 and 4,689,272 is used.

A back coat is provided on the back surface of the support, if necessary. Examples of such a back coat include a coating comprising a metal oxide obtained by hydrolyzing and polycondensing an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174. Layers are preferably used. Among these coating layers, Si (OCH ₃ ) ₄ and Si (OC
_{2 H 5) 4, Si (} OC 3 H 7) 4, Si (OC
Alkoxy compounds of silicon such as ₄ H ₉ ) ₄ are inexpensive and readily available, and a coating layer of a metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

[Exposure] As described above, the planographic printing plate precursor of the invention can be prepared. This lithographic printing plate precursor is image-exposed by a solid-state laser and a semiconductor laser that emit infrared light having a wavelength of 760 nm to 1200 nm. Scanning exposure for image formation can be performed using a known device. As the exposure apparatus, an apparatus such as an inner drum system, an outer drum system, and a flat head system can be selected and used. In the lithographic printing plate precursor according to the present invention, the polymerization reaction of undesired unexposed portions due to low-energy exposure is suppressed by a combination of a high-sensitivity specific polymerization initiator and a polymerization inhibitor. It is also suitable for an exposure process and the like, and when applied to such a process, the effect is remarkable.

In the present invention, the developing treatment may be performed immediately after the laser irradiation, but it is preferable to perform the heating treatment between the laser exposure step and the developing step. The heat treatment is preferably performed in a range of 80 ° C. to 150 ° C. for 10 seconds to 5 minutes. By this heat treatment, the laser energy required for recording at the time of laser irradiation can be reduced.

[Development] The lithographic printing plate precursor according to the invention is usually subjected to image exposure with an infrared laser, and then preferably developed with water or an aqueous alkaline solution. In the present invention, the development treatment may be performed immediately after the laser irradiation, but a heat treatment step may be provided between the laser irradiation step and the development step. The heat treatment condition is 80 ° C.-1
It is preferable to carry out for 10 seconds to 5 minutes at a temperature of 50 ° C.
By this heat treatment, the laser energy required for recording at the time of laser irradiation can be reduced. As the developer, an alkaline aqueous solution is preferable, and a preferable pH range includes a range of pH 10.5 to 12.5. It is more preferable to carry out development processing with an alkaline aqueous solution in the range of 0 to 12.5. If an alkaline aqueous solution having a pH of less than 10.5 is used, the non-image area tends to be stained, and if an aqueous solution having a pH of more than 12.5 is developed, the strength of the image area may be reduced.

When an alkaline aqueous solution is used as the developer, a conventionally known alkaline aqueous solution can be used as the developer and replenisher for the image recording material of the present invention. For example,
Sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, Inorganic alkali salts such as sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium. Also, monomethylamine, dimethylamine,
Trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, etc. Organic alkaline agents are also used. These alkali agents are used alone or in combination of two or more.

Further, when developing using an automatic developing machine, the same solution as the developing solution or an aqueous solution (replenishing solution) having a higher alkali strength than the developing solution is added to the developing solution so that the developing tank can be maintained for a long time. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the developer. This replenishment method is also preferably applied in the present invention.

Various surfactants and organic solvents can be added to the developing solution and the replenishing solution, if necessary, for the purpose of accelerating or suppressing the developing property, dispersing the developing residue and improving the ink affinity of the printing plate image area. . The surfactant is preferably added to the developer in an amount of 1 to 20% by weight, more preferably 3 to 10% by weight. If the amount of the surfactant is less than 1% by weight, the effect of improving the developability cannot be sufficiently obtained,
If added in excess of the above, adverse effects such as a decrease in strength such as abrasion resistance of the image are likely to occur. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Specifically, for example, sodium salt of lauryl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, for example, sodium salt of isopropyl naphthalene sulfonic acid, sodium salt of isobutyl naphthalene sulfonic acid, polyoxyethylene glycol Alkyl aryl sulfonates such as sodium salt of mononaphthylethyl sulfate, sodium salt of dodenylbenzenesulfonic acid, sodium salt of metanitrobenzenesulfonic acid, and higher alcohols having 8 to 22 carbon atoms such as secondary sodium alkyl sulfate esters sulfate, fatty alcohol phosphoric acid ester salts such as such as sodium salt of cetyl alcohol phosphate esters, for example C ₁₇ H ₃₃ CON (C ₃₎ CH ₂ CH ₂
Sulfonates of alkylamides such as SO ₃ Na and the like, for example, sulfonates of dibasic aliphatic esters such as dioctyl sodium sulfosuccinate and dihexyl sodium sulfosuccinate, for example, lauryl trimethyl ammonium chloride, lauryl trimethyl ammonium Ammonium salts such as methosulfate, for example, amine salts such as stearamidoethyl diethylamine acetate, for example, polyhydric alcohols such as fatty acid monoester of glycerol, and fatty acid monoester of pentaerythritol, for example, polyethylene glycol mononaphthylethyl, polyethylene And polyethylene glycol ethyls such as glycol mono (noelphenol) ethyl.

Preferred organic solvents include those having a solubility in water of about 10% by weight or less, and more preferably those having a solubility in water of 5% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenylpropanol, 1,4-phenylbutanol, 2,2-phenylbutanol, 1,2
-Phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol,
Examples thereof include benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 4-methylcyclohexanol, and 3-methylcyclohexanol. The content of the organic solvent is preferably from 1 to 5% by weight based on the total weight of the developer at the time of use. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because if the amount of the organic solvent is large when the amount of the surfactant is small, the organic solvent does not dissolve, so that good development property cannot be expected.

Further, the developer and the replenisher may contain additives such as an antifoaming agent and a water softener, if necessary. Examples of the water softener include Na ₂ P ₂ O
_{7, Na 5 P 3 O 3} , Na 3 P 3 O 9, Na 2 O 4 P (NaO
₃ P) _{ΡO 3} Na _2, polyphosphates such as Calgon (sodium polymetaphosphate), for example, ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, its potassium salt, sodium salt, triethylenetetraminehexaacetic acid , Its potassium salt, its sodium salt; hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt;
Nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt, 1,3-diamino-2
Aminopolycarboxylic acids such as propanoltetraacetic acid, its potassium salt, its sodium salt and the like;
-Phosphonobutanetricarboxylic acid-1,2,4, its potassium salt, its sodium salt; 2-phosphonobutanone tricarboxylic acid-2,3,4, its potassium salt, its sodium salt; 1-phosphonoethanetricarboxylic acid -1,
2,2, its potassium salt, its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, its potassium salt, its sodium salt; such as aminotri (methylenephosphonic acid), its potassium salt, its sodium salt, etc. Organic phosphonic acids can be mentioned. The optimum amount of such a water softener varies depending on the hardness of the hard water used and the amount thereof used. Is 0.01 ~
It may be contained in the range of 0.5% by weight. Further, when developing the lithographic printing plate using an automatic developing machine, the developer becomes fatigued according to the processing amount, so that the processing ability is restored by using a replenisher or a fresh developer. Is also good. In this case, it is preferable to replenish by the method described in U.S. Pat. No. 4,882,246.

Examples of such a developer containing a surfactant, an organic solvent and a reducing agent include, for example, those described in
Benzyl alcohol described in No. 77401,
A developer composition comprising an anionic surfactant, an alkaline agent and water, comprising an aqueous solution containing benzyl alcohol, an anionic surfactant, and a water-soluble sulfite described in JP-A-53-44202. Developer composition,
Examples thereof include a developer composition containing an organic solvent, an alkali agent, and water having a solubility in water of 10% by weight or less at room temperature described in JP-A-55-155355, which is also suitable for the present invention. Used for

The printing plate developed using the above-described developing solution and replenishing solution is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. You. As the post-processing when the image recording material of the present invention is used as a printing plate precursor, these processings can be used in various combinations.

In recent years, in the plate making / printing industry, automatic developing machines for printing plate materials have been widely used in order to rationalize and standardize plate making operations. The automatic developing machine generally includes a developing section and a post-processing section, and includes a device for transporting a printing plate material, each processing solution tank, and a spray device. The developing process is performed by spraying each pumped processing liquid from a spray nozzle. Recently, a method is also known in which a printing plate precursor is immersed and conveyed in a processing liquid tank filled with a processing liquid using a submerged guide roll or the like for processing. In such automatic processing,
Processing can be performed while replenishing each processing solution with a replenisher according to the processing amount, operating time, and the like. In addition, the electric conductivity can be detected by a sensor and replenished automatically. Further, a so-called disposable processing method in which processing is performed with a substantially unused processing liquid can also be applied.

The lithographic printing plate obtained as described above can be subjected to a printing step after applying a desensitized gum if desired. Is subjected to a burning process. When burning a lithographic printing plate, before burning,
No. 2518, No. 55-28062, JP-A-62-3
It is preferable to treat with a surface-regulating liquid as described in JP-A Nos. 1859 and 61-159655.

As a method for this, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied onto a lithographic printing plate,
A method in which a printing plate is immersed in a vat filled with a surface conditioning liquid to apply the printing plate, an application using an automatic coater, or the like is applied. Further, making the amount of the coating uniform with a squeegee or a squeegee roller after the coating gives more preferable results. The application amount of the surface conditioning liquid is generally 0.03 to 0.8 g / m ^2.
(Dry weight) is appropriate.

The lithographic printing plate to which the surface conditioning liquid has been applied is dried if necessary, and then burned (for example,
It is heated to a high temperature by a burning processor: BP-1300 sold by Fuji Photo Film Co., Ltd. The heating temperature and time in this case depend on the type of the component forming the image, but may be 1 to 180 ° C. to 300 ° C.
A range of up to 20 minutes is preferred.

The burned lithographic printing plate can be subjected to conventional treatments such as washing with water and gumming if necessary. When is used, so-called desensitizing treatment such as gumming can be omitted.

The lithographic printing plate obtained by such a process is applied to an offset printing machine or the like and used for printing a large number of sheets.

[0105]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1 to 17) [Preparation of substrate] An aluminum plate (material 1050) having a thickness of 0.3 mm was washed with trichlorethylene and degreased, and then a nylon brush and a 400-mesh pumice-water suspension were used. This surface is grained and etched.
After washing with water, it was further immersed in 20% nitric acid for 20 seconds and washed with water.
At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was provided with a DC electrode oxide film of 3 g / m ² at a current density of 15 A / dm ² using 7% sulfuric acid as an electrolyte, washed with water and dried to prepare a substrate (A). The substrate (A) is treated with a 2% by weight aqueous solution of sodium silicate at 25 ° C. for 15 minutes.
Secondly, the substrate was washed with water to prepare a substrate (B).

[Formation of Intermediate Layer] Next, S
A liquid composition (sol solution) of Method G was prepared. <Sol solution composition>-130 g of methanol-20 g of water-16 g of 85 wt% phosphoric acid-50 g of tetraethoxysilane-60 g of 3-methacryloxypropyltrimethoxysilane The above compounds were mixed and stirred. An exotherm was observed in about 5 minutes. After reacting for 60 minutes, the content was transferred to another container, and 3000 g of methanol was added to obtain a sol solution. This sol solution was diluted with methanol / ethylene glycol = 9/1 (weight ratio) so that the amount of Si on the substrate [A] prepared as described above was 3 mg / m ^2. It was applied and dried at 100 ° C. for 1 minute to obtain a substrate [C].

[Formation of Photosensitive Layer] One of the substrates [A] to [C] prepared as described above was used as a support, and a photosensitive layer coating solution having the following composition was applied to the surface thereof. 1
After drying for a minute, a photosensitive layer of 1.4 g / m ² was formed.
~ 17 planographic printing plate precursors were obtained. Substrate used, (A)
A polymerization initiator having an onium salt structure (denoted as a polymerization initiator), (B) a photothermal conversion agent, (C) a compound having a polymerizable unsaturated group (denoted as an addition polymerizable compound), (D)
The borate compound (denoted as an additive) and the binder (E) are as shown in Table 1 below.

(Coating solution for photosensitive layer)-Addition polymerizable compound (compound described in Table 1) 1.5 g-Binder (compound described in Table 1) 2.0 g-Photothermal conversion agent (compound described in Table 1) 0.1 g・ Polymerization initiator (compounds listed in Table 1) 0.2 g ・ Borate compound (compounds listed in Table 1) 0.1 g ・ 2,6-di-t-butyl-4-phenol 0.01 g ・ Fluorine nonionic surface activity Agent (MegaFac F-177P, manufactured by Dainippon Ink and Chemicals, Inc.) 0.02 g ・ Dye in which the counter anion of Victoria Pure Blue BOH is changed to 1-naphthalene sulfonic acid anion 0.04 g ・ Methyl ethyl ketone 10 g ・ Methanol 7 g ・ 2 -Methoxy-1-propanol 10 g

[0110]

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[0111]

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[0112]

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[0113]

[Table 1]

(Addition polymerizable compounds in Table 1) (M-1) pentaerythritol tetraacrylate (M-2) glycerin dimethacrylate hexamethylene diisocyanate urethane prepolymer

(Binder in Table 1) (B-1) Allyl methacrylate / methacrylic acid / N-isopropylamide copolymer (copolymerization molar ratio: 67/13/20) Acid value (actually measured by NaOH titration) 15meq / g Polymerization average molecular weight 130,000 (B-2) Allyl methacrylate / methacrylic acid copolymer (copolymerization molar ratio: 83/17) Acid value (actually measured by NaOH titration) 1.55meq / g Polymerization average molecular weight 12.5 (B-3) Polyurethane resin which is a condensate of the following diisocyanate and diol (a) 4,4'-diphenylmethane diisocyanate (b) hexamethylene diisocyanate (c) polypropylene glycol (weight average molecular weight: 10
00) (d) 2,2-bis (hydroxymethyl) propionic acid ((a) / (b) / (c) / (d) copolymer molar ratio: 40/10/1)
5/35) Acid value (actually measured by NaOH titration) 1.05 meq / g Polymerization average molecular weight 45,000

(Comparative Examples 1-4) For comparison, the substrate [A]
Or borate compounds H-1 and H-2 other than those represented by the general formula (1) are added to the substrate [C], or
Except that no borate compound was added, a photosensitive layer was formed using a photosensitive layer coating solution having the composition shown in Table 1 to obtain a lithographic printing plate precursor (Comparative Examples 1 to 4).

[0117]

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[Exposure and Development] The obtained lithographic printing plate precursor was output at a power of 500 mW, a wavelength of 830 nm, and a beam diameter of 17 μm.
After exposure at a main scanning speed of 5 m / sec using a semiconductor laser of (l / e ² ), a DN3C developer manufactured by Fuji Film Co., Ltd., or a DP-4 developer and a rinse FR-3 (1:
7) Automatic developing machine (Fuji Photo Film Co., Ltd.)
(Manufactured by PS Processor 900VR) and the following evaluation was performed. Table 1 also shows which developing solution was used in the developing process.

[Evaluation of lithographic printing plate precursor] [1. Evaluation of Sensitivity] Immediately after the preparation, the obtained lithographic printing plate precursor was exposed to a semiconductor laser emitting infrared light having a wavelength of about 830 to 850 nm. After the exposure, a developer DN-3C manufactured by Fuji Photo Film Co., Ltd. (diluted with water at a ratio of 1: 2) or a developer DP-4 manufactured by Fuji Photo Film Co., Ltd.
(Diluted with water at a ratio of 1: 8) and washed with water. The amount of energy required for recording was calculated based on the line width and laser output of the images obtained at these times, the loss in the optical system, and the scanning speed. The smaller the value, the higher the sensitivity.
These evaluation results are also shown in Table 1.

[2. Evaluation of Sensitivity Fluctuation] After the obtained lithographic printing plate precursor was stored in an atmosphere of 60 ° C. (10% RH) for 3 days, exposure and development were performed under the same conditions as in the evaluation of sensitivity, and The amount of energy required for recording was calculated. The difference between the sensitivity after storage under the high temperature condition and the sensitivity measured immediately after preparation was defined as the value of the time-dependent sensitivity variation. The smaller the value, the better the storage stability. These evaluation results are also shown in Table 1.

From the results shown in Table 1, it can be seen that the lithographic printing plate precursor according to the present invention has high sensitivity, reduced sensitivity fluctuation, and excellent storage stability. On the other hand, the lithographic printing plate precursors of Comparative Examples 1 and 3 to which the known borate compound was not added were the same as those of Examples 1 and 2 obtained under the same conditions except for the additives.
5 was inferior in both sensitivity and storage stability as compared with each other. Further, it was found that Comparative Examples 2 and 4, in which a triaryl borate having only three aromatic groups was added as the borate compound, had remarkable fluctuations in sensitivity and were inferior in storage stability.

(Examples 18 to 34, Comparative Examples 5 to 8) Polyvinyl alcohol (degree of saponification: 98) was formed on the photosensitive layer of the lithographic printing plate precursor obtained in Examples 1 to 17 and Comparative Examples 1 to 4.
Mol%, polymerization degree: 550) in an amount of 2 g / m ² after drying.
After drying for 5 minutes, a protective layer was provided on the photosensitive layer.
Thus, a lithographic printing plate precursor No. 4 was obtained. The obtained lithographic printing plate precursor was exposed and developed under the same conditions as in Examples 1 to 17 described above to produce a lithographic printing plate, and the sensitivity and the change in sensitivity over time were evaluated in the same manner. The results are shown in Table 1 above.

From the results shown in Table 1, it can be seen from Examples 1 to 17 that no protective layer was provided even when a protective layer was provided on the photosensitive layer.
The same tendency as that of Comparative Examples 1 to 4 was observed, and the lithographic printing plate precursor of the present invention was excellent in sensitivity, little in sensitivity fluctuation upon storage, and excellent in storage stability, but was used in combination with a borate compound additive. All of the comparative examples which did not have a problem in sensitivity and storage stability. In Comparative Examples 6 and 8 to which triaryl borate was added, images were not formed due to poor development. This is because it was left at 60 ° C for a long time,
It is presumed that the triarylborate compound was decomposed in a small amount and was not deactivated by oxygen due to the presence of the protective layer, and the polymerization reaction proceeded.

[0124]

The negative type lithographic printing plate precursor according to the present invention is writable by an infrared laser, has excellent sensitivity at the time of recording, suppresses a decrease in sensitivity over time, and has excellent storage stability. Play.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/027 G03F 7/027 (72) Inventor Tadahiro Soro 4,000 Kawajiri, Yoshida-cho, Harihara-gun, Shizuoka Prefecture Fuji Photo film F-term (reference) 2H025 AA01 AB03 AC08 AD01 BC31 BC34 CA39 CA48 CC01 CC11 2H096 AA06 BA05 EA04 EA23 2H114 AA04 AA14 AA22 AA24 BA01 BA10 DA21 DA25 DA28 DA47 EA01 EA02

Claims (1)

[Claims] 1. A support comprising, on a support, (A) a polymerization initiator having an onium salt structure, (B) a photothermal conversion agent, (C) a compound having a polymerizable unsaturated group, and (D) a compound having the following general formula: (1)
A heat-mode-compatible negative-working lithographic printing plate precursor comprising a photosensitive layer containing a borate compound represented by formula (1) and recordable with an infrared laser. [General formula (1)] Ar ₄ B ^- M ^{+ wherein} M ⁺ is a monovalent cation, and Ar is each independently
Represents an aromatic group.