JP4141492B2 - Negative type planographic printing plate precursor - Google Patents

Description

  The present invention relates to a negative type image recording material writable by an infrared laser, and more particularly, to a negative type lithographic printing plate precursor capable of forming a lithographic printing plate having high strength of an image portion of a recording layer and excellent printing durability. .

In recent years, the development of lasers has been remarkable. In particular, solid lasers and semiconductor lasers having a light emitting region from the near infrared region to the infrared region have been increasing in output and size. Therefore, these lasers are very useful as an exposure light source when making a plate directly from digital data such as a computer.
The above-mentioned infrared laser having a light emitting region in the infrared region is used as an exposure light source. The negative lithographic printing plate material for infrared laser includes an infrared absorber, a polymerization initiator that generates radicals by light or heat, and a polymerizable compound. A lithographic printing plate material having a photosensitive layer comprising:

Usually, such a negative type image recording material uses a recording system in which a radical generated by light or heat is used as an initiator to cause a polymerization reaction, and a recording layer in an exposed portion is cured to form an image portion. Yes. Such a negative type image forming material has a lower image forming property than a positive type in which the recording layer is solubilized by the energy of infrared laser irradiation, and promotes a curing reaction by polymerization to provide a strong image portion. In order to form, it is common to heat-process before a image development process.
As a printing plate having such a light- or heat-polymerized recording layer, a photopolymerizable or heat-polymerizable composition as described in JP-A-8-108621 and JP-A-9-34110. A technique of using as a photosensitive layer is known. Although these photosensitive layers are excellent in high-sensitivity image-forming properties, when a hydrophilically treated substrate is used as a support, adhesion at the interface between the photosensitive layer and the support is low, and printing durability is poor. There was a problem.
In addition, in order to improve the sensitivity, use of a high-power infrared laser has been studied, but there is also a problem that the photosensitive layer is ablated during laser scanning and contaminates the optical system.

  The present invention has been made in consideration of the above-mentioned problems, and the object of the present invention is a lithographic plate in which ablation in laser scanning during recording is suppressed, the strength of the formed image portion is high, and the printing durability is excellent. An object of the present invention is to provide a negative type image recording material capable of forming a printing plate.

As a result of intensive studies, the present inventors have made recording with excellent image area strength by using a resin having a specific unsaturated group as a polymer compound insoluble in water and soluble in an alkaline aqueous solution. The present invention has been completed by finding that it is possible.
That is, the heat mode-compatible negative planographic printing plate precursor of the present invention has (A) a side chain having at least one group represented by the following general formulas (1) to (3), insoluble in water and alkaline A polymer compound soluble in an aqueous solution, (B) a photothermal conversion agent, (C) represented by the following general formula (V), and (B) a radical by heat mode exposure of light of a wavelength that can be absorbed by the photothermal conversion agent. And (D) a radical polymerizable compound, and image recording is possible by heat mode exposure.

In the formula, R ^{1 to} R ¹¹ each independently represents a monovalent organic group. X and Y each independently represent an oxygen atom, a sulfur atom, or —N—R ¹² , and Z represents an oxygen atom, a sulfur atom, —N—R ^12, or a phenylene group. R ¹² represents a hydrogen atom or a monovalent organic group.

In the formula (V), R ³¹ , R ³² and R ³³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Z ^31- represents a perchlorate ion, a hexafluorophosphate ion, or an aryl sulfonate ion. Among these, Z ^31- is more preferably an aryl sulfonate ion.

  The present invention is also characterized in that (B) the photothermal conversion agent is an infrared absorbing dye. In the present invention, the infrared absorbing pigment is a dye. In the invention, it is preferable that the dye is a cyanine dye. Furthermore, the present invention is characterized in that the dye is a compound represented by the following general formula (I).

In the general formula (I), X ¹ represents a halogen atom or X ² -L ¹ . Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and ^{R 2} are bonded to each other to form a 5- or 6-membered ring. Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group. Y ¹ and Y ² each independently represent a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ each independently represents a hydrocarbon group having 20 or less carbon atoms. R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. Z ^1- represents a counter anion.

  Further, in the present invention, the above (A) is produced by a production method in which one or more radical polymerizable compounds represented by the following general formula (12) are polymerized, and then a proton is extracted and a Z is eliminated using a base. And a heat-mode-compatible negative lithographic printing plate precursor having a group represented by the following general formula (1) in the side chain and insoluble in water and soluble in an alkaline aqueous solution: And

^Wherein, R 1 to R ³ each independently represents a monovalent organic group. X represents an oxygen atom, a sulfur atom, or —N—R ¹² , and R ¹² represents a hydrogen atom or a monovalent organic group.

In the formula, Z represents an anionic leaving group. Q represents an oxygen atom, —NH—, or —NR ¹⁴ — (wherein R ¹⁴ represents an alkyl group which may have a substituent). R ¹³ represents a hydrogen atom or an alkyl group which may have a substituent. A represents a divalent organic linking group. X and R < ¹ > -R < ³ > are synonymous with X and R < ¹ > -R < ³ > in General formula (1).

  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 this invention is explained in full detail. Hans-Joachim Time, IS & Ts NIP 15: 1999 International Conference on Digital Printing Technologies. P. 209, a photoabsorbing substance (for example, a dye) is photoexcited in a photosensitive material, and undergoes a chemical or physical change to form an image, from the photoexcitation of the photoabsorbing substance to a chemical or physical change. It is known that there are two modes in the above process. One is that the photo-excited light-absorbing substance is deactivated by some photochemical interaction (for example, energy transfer, electron transfer) with other reactants in the photosensitive material, and as a result, the activated reactant is The so-called photon mode that causes the chemical or physical change necessary for the above-described image formation, and the other is that the photo-excited light-absorbing material generates heat and deactivates, and the reaction material is converted into the above-described using the heat. This is a so-called heat mode that causes a chemical or physical change necessary for image formation. In addition, there are special modes such as ablation that explosively scatters by the energy of light gathered locally, and multiphoton absorption in which one molecule absorbs a large number of photons at once.

  The exposure process using each of the above modes is 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 target reaction energy amount. For example, consider that a certain reaction is caused by using n photons. In photon mode exposure, photochemical interaction is used, so that one-photon energy cannot be added together due to the requirement of quantum energy and momentum conservation laws. That is, in order to cause some kind of reaction, a relationship of “one photon energy amount ≧ reaction energy amount” 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, it is sufficient that there is a relationship of “energy amount of n photons ≧ energy amount of reaction”. However, this energy amount addition is restricted by thermal diffusion. That is, if the next photoexcitation-deactivation process occurs and the heat is generated before the heat escapes from the exposed portion (reaction point) of interest now, due to thermal diffusion, the heat is surely accumulated and added, and the temperature of that portion increases. Leads to. However, when the next heat generation is slow, the heat escapes and does not accumulate. In other words, in the heat mode exposure, even when the same total exposure energy amount is used, the result is different between the case where the high energy amount light is irradiated for a short time and the case where the low energy amount light is irradiated for a long time. It becomes advantageous for accumulation.

Of course, in the photon mode exposure, a similar phenomenon may occur due to the diffusion of the subsequent reactive species, but basically this 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 (energy for reaction necessary for image formation) with respect to the exposure power density (w / cm ² ) (= energy density per unit time). In the heat mode, the intrinsic sensitivity of the photosensitive material increases with respect to the exposure power density. Therefore, when the exposure time is fixed so that the necessary productivity can be maintained in practice as an image recording material, when comparing the modes, the photon mode exposure usually has a high sensitivity of about 0.1 mJ / cm ^2. However, since the reaction occurs at any small exposure dose, the problem of low exposure fogging in unexposed areas is likely to occur. In contrast, no reaction occurs not the exposure amount of certain level or more in the heat mode exposure, also usually is required about 50 mJ / cm ² from the relationship between the thermal stability of the photosensitive material, the low exposure fogging problem Is avoided.
And, in fact heat mode exposure requires exposure power density at the plate surface of the photosensitive material is 5000 W / cm ² or more, preferably it is necessary to 10000 W / cm ² or more. However, although not described in detail here, the use of a high power density laser of 5.0 × 10 ⁵ / cm ² or more is not preferable because of problems such as ablation and contamination of the light source.

  Although the action of the present invention is not clear, in the image recording material of the present invention, the group represented by the following general formulas (1) to (3) on the side chain (A) as a polymer compound capable of alkaline aqueous solution. However, since this polymer compound has a side chain substituent having high radical reactivity, this image recording material was used for the photosensitive layer of the lithographic printing plate precursor for heat mode. In this case, after radicals are generated due to infrared laser scanning exposure, a crosslinking reaction is quickly caused to form a cured film having a high crosslinking density, so that other low molecular components such as a photothermal conversion agent cause ablation. It is considered that the release from the photosensitive layer is suppressed and the contamination of the optical system such as the spinner mirror is suppressed.

Furthermore, in heat mode compatible lithographic printing plate precursors, an aluminum substrate support is often used, but due to the thermal diffusivity of aluminum, heat due to heat mode exposure is not sufficiently transmitted to the vicinity of the substrate interface of the heat sensitive layer. In the vicinity of the substrate interface between the photosensitive layer and the support, a sufficient curing reaction does not proceed. When the latent image formed in such a state is developed using an alkaline developer, the cured photosensitive layer is also exposed from above. There is a problem that the developer penetrates easily, the hardened portion near the interface is dissolved, the image strength is lowered, and a lithographic printing plate with low printing durability is obtained. However, when the polymer compound used in the present invention is used as a binder for the photosensitive layer, the cross-linking density of the cured portion increases, so that the penetration of the developer is effectively suppressed and the damage received by the image portion is reduced. It is considered that the printing durability is improved.
This (A) polymer compound used in the present invention is represented by (C) the general formula (V), and is an onium salt compound as a compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent. The effect is remarkable when using. This seems to be due to the excellent compatibility between the polymer compound and the onium salt compound.

  According to the present invention, recording can be performed directly from digital data such as a computer by recording using a solid-state laser and a semiconductor laser emitting infrared rays, and ablation occurs when used for a photosensitive layer for a lithographic printing plate precursor. Therefore, it is possible to provide a negative image recording material capable of forming a high-strength image and achieving excellent printing durability.

Hereinafter, the present invention will be described in detail.
The negative lithographic printing plate precursor according to the present invention comprises (A) a polymer having at least one group represented by general formula (1) to general formula (3) in the side chain and insoluble in water and soluble in an aqueous alkali solution. A compound, (B) a photothermal conversion agent, (C) an onium salt compound that is represented by the general formula (V), and (B) generates a radical by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent, and ( D) It contains a radically polymerizable compound. Below, each compound which can be used for the image recording material of this invention is demonstrated one by one.

[(A) Polymer compound having at least one group represented by general formula (1) to general formula (3) in the side chain and insoluble in water and soluble in an alkaline aqueous solution (hereinafter referred to as a specific alkali-soluble resin as appropriate) Called)]]

In the general formula (1), R ^{1 to} R ³ each independently represents a monovalent organic group, and examples of R ¹ include a hydrogen atom or an alkyl group which may have a substituent. Of these, a hydrogen atom, a methyl group, a methylalkoxy group, and a methyl ester group are preferable. R ² and R ³ may each independently have a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or a substituent. Alkyl group, aryl group which may have a substituent, alkoxy group which may have a substituent, aryloxy group which may have a substituent, alkylamino group which may have a substituent, substituted An arylamino group which may have a group, an alkylsulfonyl group which may have a substituent, or an arylsulfonyl group which may have a substituent, among which a hydrogen atom, a carboxyl group, alkoxy A carbonyl group, an alkyl group which may have a substituent, or an aryl group which may have a substituent is preferable.
Here, examples of the substituent that can be introduced include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, a methyl group, an ethyl group, and a phenyl group.
X represents an oxygen atom, a sulfur atom, or —N—R ¹² , where R ¹² includes an alkyl group which may have a substituent.

In the general formula (2), R ⁴ ~R ⁸ may each independently represent a monovalent organic group, R ⁴ to R ⁸ include a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl Group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, alkyl group which may have a substituent, aryl group which may have a substituent, alkoxy group which may have a substituent, substituent An aryloxy group which may have a substituent, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, or a substituent An arylsulfonyl group that may have, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group that may have a substituent, or an aryl group that may have a substituent preferable. Examples of the substituent that can be introduced include those listed in the general formula (1). Y represents an oxygen atom, a sulfur atom, or —N—R ¹² . Examples of R ¹² include the same as those in the general formula (1).
In the general formula (3), R ^{9 to} R ^ll each independently represent a monovalent organic group. Specific examples of the organic group include a hydrogen atom, a halogen atom, an amino group, and a dialkylamino group. Group, carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, alkyl group which may have a substituent, aryl group which may have a substituent, alkoxy group which may have a substituent , An aryloxy group which may have a substituent, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, or An arylsulfonyl group which may have a substituent, and the like are mentioned. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, an alkyl group which may have a substituent, or a substituent An aryl group is preferable.
Here, as a substituent, what was mentioned in General formula (1) is illustrated similarly.
Z represents an oxygen atom, a sulfur atom, —N—R ¹² or a phenylene group. Examples of R ¹² include the same as those in the general formula (1).

  Among the (A) specific alkali-soluble resins used as essential components in the heat mode-compatible negative image recording material of the present invention, the compound having a group represented by the general formula (1) is shown below 1), 2 1), but 1) is more preferable.

Synthesis method 1)
After synthesizing one or more radically polymerizable compounds represented by the following general formula (12) to synthesize a polymer compound, a desired polymer compound is obtained by extracting a proton and desorbing Z using a base. How to get.

In the formula, Z represents an anionic leaving group. Q represents an oxygen atom, —NH—, or —NR ¹⁴ — (wherein R ¹⁴ represents an alkyl group which may have a substituent). R ¹³ includes a hydrogen atom or an alkyl group which may have a substituent, and among them, a hydrogen atom, a methyl group, a methylalkoxy group, or a methyl ester group is preferable. A represents a divalent organic linking group. X and R < ¹ > -R < ³ > are synonymous with X and R < ¹ > -R < ³ > in General formula (1).

Synthesis method 2)
After synthesizing one or more radically polymerizable compounds having a functional group to synthesize a trunk polymer compound (polymer compound constituting the main chain), the side chain functional group of the trunk polymer compound and the general formula (13) A method of obtaining a desired polymer compound by reacting a compound having a structure represented by the formula:

  Examples of the radical polymerizable compound represented by the general formula (12) include, but are not limited to, the following compounds.

These radically polymerizable compounds represented by the general formula (12) can be easily obtained as a commercial product or by a synthesis method shown in Synthesis Examples described later.
One or more of these radically polymerizable compounds and, if necessary, other radically polymerizable compounds are polymerized by an ordinary radical polymerization method to synthesize a polymer compound, and then a desired amount of base is polymerized. The group represented by the general formula (1) can be introduced by dropping and reacting in the solution under cooling or heating conditions and, if necessary, neutralizing treatment with an acid. A generally known suspension polymerization method or solution polymerization method can be applied to the production of the polymer compound.
As the base, either an inorganic compound or an organic compound may be used. Preferred inorganic bases include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and the like, and organic bases include sodium methoxide, sodium ethoxide, potassium t-butoxide. And metal amine alkoxides, triethylamine, pyridine, and organic amine compounds such as diisopropylethylamine.

Examples of the functional group of the radical polymerizable compound having a functional group used for the synthesis of the trunk polymer compound in the synthesis method 2) include a hydroxyl group, a carboxyl group, a carboxylic acid halide group, a carboxylic acid anhydride group, an amino group, and a halogenated group. Examples thereof include an alkyl group, an isocyanate group, and an epoxy group. Examples of radically polymerizable compounds having these functional groups include 2-hydroxylethyl acrylate, 2-hydroxylethyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, acrylic acid, methacrylic acid, acrylic acid chloride, and methacrylic acid chloride. Methacrylic anhydride, N, N-dimethyl-2-aminoethyl methacrylate, 2-chloroethyl methacrylate, 2-isocyanate ethyl methacrylate, glycidyl acrylate, and grindyl methacrylate.
One or more kinds of such radically polymerizable compounds are polymerized and copolymerized with other radically polymerizable compounds as necessary to synthesize a trunk polymer compound, and then a group represented by the general formula (13) is formed. The desired polymer compound can be obtained by reacting the compound having the compound.
Here, as an example of the compound having the group represented by the general formula (13), the compounds mentioned as examples of the radical polymerizable compound having the functional group described above can be given.

The polymer compound having a group represented by the general formula (2) according to the present invention can be produced by at least one of the synthesis methods 3) and 4) shown below.
Synthesis method 3)
-One or more radically polymerizable compounds having an unsaturated group represented by the general formula (2) and an ethylenically unsaturated group further enriched in addition polymerization than the unsaturated group, and if necessary A method of polymerizing another radical polymerizable compound to obtain a polymer compound. This method uses a compound having a plurality of ethylenically unsaturated groups having different addition polymerization properties in one molecule, for example, a compound such as allyl methacrylate.

Synthesis method 4)
After synthesizing one or more radically polymerizable compounds having a functional group to synthesize a polymer compound, a side chain functional group and a compound having a structure represented by the following general formula (14) are reacted to form a general formula (2 The method of introduce | transducing group represented by this.

Examples of the radically polymerizable compound having an unsaturated group represented by the general formula (2) and an ethylenically unsaturated group having a higher addition polymerizability than the unsaturated group include allyl acrylate, allyl methacrylate, 2- Allyloxyethyl acrylate, 2-allyloxyethyl methacrylate, propargyl acrylate, propargyl methacrylate, N-allyl acrylate, N-allyl methacrylate, N, N-diallyl acrylate, N, N-diallyl methacrylate, allyl acrylamide, allyl methacrylamide, etc. Take as an example.
Examples of the polymer compound obtained by polymerizing one or more radically polymerizable compounds having a functional group include the examples shown in the above synthesis method 2).

  Examples of the compound having the structure represented by the general formula (14) include allyl alcohol, allylamine, diallylamine, 2-allyloxyethyl alcohol, 2-chloro-1-butene, and allyl isocyanate.

The polymer compound having a group represented by the general formula (3) according to the present invention can be produced by at least one of the synthesis methods 5) and 6) shown below.
Synthesis method 5)
-Polymerizing one or more radically polymerizable compounds having an unsaturated group represented by the general formula (3) and an ethylenically unsaturated group further rich in addition polymerizability than the unsaturated group, and if necessary To obtain a polymer compound by copolymerizing with other radical polymerizable compounds.

Synthesis method 6)
A method in which one or more radically polymerizable compounds having a functional group are polymerized to synthesize a polymer compound, and then a side chain functional group and a compound having a structure represented by the general formula (15) are reacted and introduced.

Examples of the radically polymerizable compound having an unsaturated group represented by the general formula (3) and an ethylenically unsaturated group having a higher addition polymerizability than the unsaturated group include vinyl acrylate, vinyl methacrylate, and 2-phenyl. Examples include vinyl acrylate, 2-phenylvinyl methacrylate, 1-propenyl acrylate, 1-propenyl methacrylate, vinyl acrylamide, vinyl methacrylamide and the like.
Examples of the polymer compound obtained by polymerizing one or more radically polymerizable compounds having a functional group include those shown in the aforementioned synthesis method 2).
Examples of the compound having the structure represented by the general formula (15) include 2-hydroxyethyl monovinyl ether, 4-hydroxybutyl monovinyl ether, diethylene glycol monovinyl ether, 4-chloromethylstyrene and the like.

Below, the typical synthesis example and specific polymer compound of (A) specific alkali-soluble resin which concern on this invention are given, However, This invention is not restrict | limited to these.
(1) Synthesis of Compound (M-1) In a 1000 ml three-necked flask, a solution of 133 g of 2-hydroxyethyl methacrylate in 520 ml of THF was prepared and cooled to 0 ° C. While stirring, 130 g of 3-chloropropionic acid chloride was dropped over 1 hour using a dropping funnel, and then the temperature was gradually raised to room temperature. After stirring for 12 hours at room temperature, the reaction mixture was poured into 1 l of ice water. After stirring for 1 hour, the mixture was extracted with 2 l of ethyl acetate three times, and the obtained organic layer was washed successively with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine, and then dried over magnesium sulfate. After filtration, the solvent was distilled off under reduced pressure using a rotary evaporator. The obtained residue was purified by silica gel column chromatography (elution solvent; hexane / ethyl acetate) to obtain 180 g of compound (M-1). The structure of the compound (M-1) was confirmed from NMR, mass spectrometry spectrum and IR.

(2) Synthesis of Compound (M-5) Compound (M-5) was synthesized by using 4-hydroxybutyl methacrylate instead of 2-hydroxyethyl methacrylate in the same manner as the synthesis of compound (M-1). did.

(3) Synthesis of Compound (M-8) In a 1000 ml three-necked flask, a solution of 49 g of ethanolamine in 500 ml of THF was prepared and cooled to 0 ° C. While stirring, 51 g of 3-chloropropionic acid chloride was dropped using a dropping funnel over 1 hour, and then the temperature was gradually raised to room temperature. After stirring at room temperature for 12 hours, the mixture was filtered and the solvent was distilled off under reduced pressure. 10 g of the obtained residue was placed in a 100 ml three-necked flask, dissolved in 50 ml of THF, and cooled to 0 ° C. While stirring, 7 g of methacrylic acid chloride was dropped using a dropping funnel over 30 minutes, and then the temperature was gradually raised to room temperature. After stirring at room temperature for 12 hours, the reaction mixture was poured into 300 ml of ice water. After stirring for 1 hour, the reaction mixture was extracted three times with 1 l of ethyl acetate, and the obtained organic layer was washed successively with water, saturated aqueous sodium hydrogen carbonate solution and saturated brine, and then dried over magnesium sulfate. After filtration, the solvent was distilled off under reduced pressure using a rotary evaporator. The obtained residue was purified by silica gel column chromatography (elution solvent; hexane / ethyl acetate) to obtain 8 g of compound (M-8). The structure of the compound (M-8) was confirmed from NMR, mass spectrometry spectrum and IR.

(4) Synthesis of Compound (M-9) Compound (M-9) is synthesized by using 4-hydroxy-1-butylamine instead of ethanolamine in the same manner as the synthesis of Compound (M-8). did.

Synthesis of polymer compound (1) [specific example of synthesis method 1]
In a 500 ml three-necked flask equipped with a condenser and a stirrer, 80 ml of 1-methoxy-2-propanol was placed and heated to 70 ° C. Under a nitrogen stream, 53.0 g of Example M-1, 5.2 g of methacrylic acid, V-65 (manufactured by Wako Pure Chemical Industries, Ltd.), 0.746 g of 1-methoxy-2-propanol 80 ml solution was dropped over 2 and a half hours. . Furthermore, it was made to react at 70 degreeC for 2 hours. The reaction mixture was diluted with 100 ml of 1-methoxy-2-propanol, cooled to 0 ° C., then 33.4 g of triethylamine was added dropwise with stirring, and the mixture was allowed to react for 12 hours while gradually warming to room temperature. After cooling the reaction mixture to 0 ° C., 5M HCl was added dropwise with stirring until the pH of the reaction mixture was 6 or less. The reaction solution was poured into 3 l of water to precipitate a polymer. This was filtered, washed and dried to obtain a polymer compound (1). From the NMR spectrum, it was confirmed that all M-1 completed groups were converted to acrylic groups. The weight average molecular weight was measured by gel permeation chromatography (GPC) using polystyrene as a standard substance, and the result was 80,000.

Synthesis of Polymer Compound (2) [Specific Example of Synthesis Method 2]
A 500 ml three-necked flask equipped with a condenser and a stirrer was charged with 90 ml of methyl ethyl ketone and heated to 70 ° C. Under a nitrogen stream, 15.6 g of 2-hydroxyethyl methacrylate, 5.2 g of methacrylic acid, 12.0 g of methyl methacrylate, and 0.775 g of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) in 90 ml of methyl ethyl ketone were dropped over 2 and a half hours. . Furthermore, it was made to react at 70 degreeC for 2 hours. After cooling the reaction mixture to 0 ° C., 10.9 g of acrylic acid chloride was added dropwise with stirring, and the mixture was allowed to react for 12 hours while gradually warming to room temperature. The reaction solution was poured into 3 l of water to precipitate a polymer. This was filtered, washed and dried to obtain a polymer compound (10). It was confirmed from the NMR spectrum that an acrylic group was introduced into the side chain by the polymer reaction. The weight average molecular weight measured by gel permeation chromatography (GPC) using polystyrene as a standard substance was 78,000.

Synthesis of Polymer Compound (3) [Specific Example of Synthesis Method 3]
In a 1000 ml three-necked flask equipped with a condenser and a stirrer, 200 ml of 1-methoxy-2-propanol was placed and heated to 70 ° C. Under a nitrogen stream, 200 ml of 1-methoxy-2-propanol in an amount of 40.9 g of 2-allyloxyethyl methacrylate, 5.2 g of methacrylic acid, and 0.746 g of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) was dropped over 2 and a half hours. It was. Furthermore, it was made to react at 70 degreeC for 2 hours. This was filtered, washed and dried to obtain a polymer compound (3). It was 110,000 as a result of measuring a weight average molecular weight by gel permeation chromatography method (GPC) which used polystyrene as a standard substance.

Synthesis of Polymer Compound (4) [Specific Example of Synthesis Method 4]
A 500 ml three-necked flask equipped with a condenser and a stirrer was charged with 80 ml of methyl ethyl ketone and heated to 70 ° C. Under a nitrogen stream, a solution of 12.5 g of methacrylic acid chloride, 5.2 g of methacrylic acid, 12.0 g of methyl methacrylate, and 0.700 g of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) in 80 ml of methyl ethyl ketone was dropped over 2 and a half hours. Furthermore, it was made to react at 70 degreeC for 2 hours. After cooling the reaction mixture to 0 ° C., 12.5 g of 2-allyloxyethyl alcohol was added dropwise with stirring, and the mixture was allowed to react for 12 hours while gradually warming to room temperature. The reaction solution was poured into 3 l of water to precipitate a polymer. This was filtered, washed and dried to obtain a polymer compound (4). It was confirmed from the NMR spectrum that the allyl group was introduced into the side chain by the polymer reaction. The weight average molecular weight was measured by gel permeation chromatography (GPC) using polystyrene as a standard substance. As a result, it was 95,000.

Synthesis of Polymer Compound (5) [Specific Example of Synthesis Method 5]
A 500 ml three-necked flask equipped with a condenser and a stirrer was charged with 150 ml of 1-methoxy-2-propanol and heated to 70 ° C. Under a nitrogen stream, a solution of vinyl methacrylate 26.9 g, methacrylic acid 5.2 g, and V-65 (manufactured by Wako Pure Chemical Industries) 0.780 g of 1-methoxy-2-propanol 150 ml was dropped over 2 and a half hours. Furthermore, it was made to react at 70 degreeC for 2 hours. This was collected by filtration, washed and dried to obtain a polymer compound (5). It was 120,000 as a result of measuring a weight average molecular weight by gel permeation chromatography method (GPC) which used polystyrene as a standard substance.

Synthesis of Polymer Compound (6) [Specific Example of Synthesis Method 6]
A 500 ml three-necked flask equipped with a condenser and a stirrer was charged with 100 ml of methyl ethyl ketone and heated to 70 ° C. Under a nitrogen stream, a solution of 12.5 g of methacrylic acid chloride, 5.2 g of methacrylic acid, 12.0 g of methyl methacrylate, and 0.700 g of V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) in 100 ml of methyl ethyl ketone was dropped over 2 hours and a half. Furthermore, it was made to react at 70 degreeC for 2 hours. After cooling the reaction mixture to 0 ° C., 11.0 g of 2-hydroxyethermonovinyl ether was added dropwise with stirring, and the mixture was allowed to react for 12 hours while gradually warming to room temperature. The reaction solution was poured into 3 l of water to precipitate a polymer. This was collected, washed and dried to obtain a polymer compound (6). It was confirmed from the NMR spectrum that a vinyl group was introduced into the side chain by the polymer reaction. The weight average molecular weight measured by gel permeation chromatography (GPC) using polystyrene as a standard substance was 95,000.

Synthesis Examples 7 to 23;
In the same manner as in Synthesis Examples 1 to 6, polymer monomer polymers 7 to 23 shown below were synthesized by changing the charged monomer type and composition ratio. The weight average molecular weights of these polymers were measured by the same method as in Synthesis Examples 1-6.
The specific alkali-soluble resin (A) obtained by the above synthesis method is displayed in the following Tables 1 to 5 in terms of the structural unit structure and polymerization molar ratio, and the measured weight average molecular weight is also shown. [(Polymer Compound No. 1) to (Polymer Compound No. 23)]

The specific alkali-soluble resin according to the present invention is not limited to the above-mentioned radical polymerizable compound, in order to improve various performances such as image strength, as long as the effects of the present invention are not impaired. It is also a preferred embodiment to copolymerize.
Examples of the radical polymerizable compound that can be copolymerized with a specific alkali-soluble resin in the present invention include acrylic esters, methacrylic esters, N, N-2 substituted acrylamides, and N, N-2 substituted methacrylamides. Radical polymerizable compounds selected from styrene, styrenes, acrylonitriles, methacrylonitriles, and the like.

  Specifically, for example, acrylic esters such as alkyl acrylate (the alkyl group preferably has 1 to 20 carbon atoms) (specifically, for example, methyl acrylate, ethyl acrylate, acrylic Propyl acrylate, butyl acrylate, amyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane Monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.), aryl acrylate (for example, Such as E nil acrylate),

  Methacrylic acid esters (for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate) such as alkyl methacrylate (the alkyl group preferably has 1 to 20 carbon atoms) , Chlorobenzyl methacrylate, octyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, furfuryl Methacrylate, tetrahydrofurfuryl methacrylate, etc.) Aryl methacrylates (e.g., phenyl methacrylate, cresyl methacrylate, naphthyl methacrylate, etc.),

  Styrenes such as styrene and alkyl styrene (for example, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene) , Trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene etc.), alkoxy styrene (eg methoxy styrene, 4-methoxy-3-methyl styrene, dimethoxy styrene etc.), halogen styrene (eg chloro styrene, dichloro styrene, trichloro styrene) , Tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluoro Styrene, 2-bromo-4-trifluoromethyl styrene, 4-fluoro-3-trifluoromethyl styrene etc.), acrylonitrile, methacrylonitrile, and the like.

Of these radical polymerizable compounds, acrylic acid esters, methacrylic acid esters, and styrenes are preferably used.
These can be used singly or in combination of two or more. The content of these copolymerization components used is preferably 0 to 95 mol%, particularly preferably 20 to 90 mol%.

In order to improve various performances such as non-image area removability, the (A) specific alkaline water-soluble polymer according to the present invention may be copolymerized with a radically polymerizable compound having an acid group. Examples of such an acid group having radical polymerizability include a carboxylic acid, a sulfonic acid, and a phosphoric acid group, and a particularly preferable one is a carboxylic acid. Examples of the radical polymerizable compound containing a carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, incrotonic acid, maleic acid, p-carboxyl styrene, and particularly preferred are acrylic acid, methacrylic acid, and the like. Acid, p-carboxylstyrene.
These may be used alone or in combination of one or more. The content of these copolymer components is preferably 0 to 85 mol%, particularly preferably 10 to 70 mol%.

  The alkaline water-soluble polymer according to the present invention may be a homopolymer, but radically polymerizable compounds having groups represented by different general formulas (1) to (3), or a general formula ( When it is a copolymer of one or more radically polymerizable compounds having a group represented by 1) to general formula (3) and one or more other radically polymerizable compounds described above, the constitution of the copolymer May be any of a block copolymer, a random copolymer, a graft copolymer, and the like.

Examples of the solvent used for synthesizing such a polymer compound include ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxy. Examples include ethyl acetate, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, toluene, ethyl acetate, methyl lactate, and ethyl lactate. It is done.
These solvents may be used alone or in combination of two or more.

The polymer compound [component (A)] according to the present invention has a weight average molecular weight of preferably 2,000 or more, more preferably 5,000 to 300,000.
In addition, the specific alkaline water-soluble polymer according to the present invention may contain an unreacted monomer. In this case, the proportion of the monomer in the polymer compound is desirably 15% by weight or less.
The content of the specific alkali-soluble resin (A) contained in the image recording material of the present invention is about 5 to 95% by weight, preferably about 10 to 85% by weight in terms of solid content. If the amount added is less than 5% by weight, the strength of the image area may be insufficient when an image is formed. If the added amount exceeds 95% by weight, an image may not be formed.

[(B) Photothermal conversion agent]
Since the image recording material of the present invention performs recording by heat mode exposure, typically, a laser emitting infrared rays, it is essential to use a photothermal conversion agent. The photothermal conversion agent has a function of absorbing light of a predetermined wavelength and converting it into heat. The heat generated at this time decomposes the onium salt compound that generates radicals by heat mode exposure of light having a wavelength that can be absorbed by the component (C), that is, the photothermal conversion agent (B), and generates radicals. The photothermal conversion agent used in the present invention is not limited as long as it has a function of converting absorbed light into heat, but generally, the wavelength of the infrared laser used for writing, that is, the wavelength from 760 nm to 1200 nm. Examples thereof include dyes or pigments known as infrared absorbers having an absorption maximum.

  As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.

  Preferred dyes include, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-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-58-224793, JP-A-59- 48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc., naphthoquinone dyes, JP-A-58-112792, etc. And cyanine dyes described in British Patent 434,875.

  Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, cyanine dyes described in JP-A-59-216146, U.S. Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. .

  Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

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.

In the general formula (I), X ¹ represents a halogen atom or X ² -L ^1,. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the photosensitive layer coating solution, R ¹ and R ² are bonded to each other to form a 5-membered ring or a 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. 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. Further, Z ^1-represents a counter anion. However, Z ^1- is not necessary when any of R ^{1 to} R ⁸ is substituted with a sulfo group. Preferred Z ¹⁻ 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 photosensitive layer coating solution. Hexafluorophosphate ions and aryl sulfonate ions.

  Specific examples of cyanine dyes represented by formula (I) that can be suitably used in the present invention are those described in paragraphs [0017] to [0019] of Japanese Patent Application No. 11-310623. Can be mentioned.

  Examples of the pigment used in the present invention include commercially available pigments and color index (CI) manual, “Latest Pigment Handbook” (edited by Japan Pigment Technology Association, published in 1977), “Latest Pigment Application Technology” (CMC Publishing, 1986), “Printing Ink Technology”, CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  These pigments may be used without surface treatment or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The surface treatment methods described above are described in “Characteristics and Applications of Metal Soap” (Sachibo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

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

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

  These photothermal conversion agents may be added to the same layer as other components, or may be added to another layer, but when the negative type image forming material is prepared, The optical density at the absorption maximum in the wavelength range of 760 nm to 1200 nm is preferably between 0.1 and 3.0. When this range is deviated, the sensitivity tends to be low. Since the optical density is determined by the amount of the photothermal conversion agent added and the thickness of the recording layer, the 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 recording 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 a transmission optical densitometer is used. Examples thereof include a measuring method, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.

[(C) An onium salt compound that is represented by the following general formula (V), and (B) generates a radical by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent.
An onium salt compound (hereinafter referred to as a radical initiator as appropriate) that generates radicals by heat mode exposure is used in combination with the (B) photothermal conversion agent, and has a wavelength that can be absorbed by the photothermal conversion agent, for example, an infrared laser. , Radicals are generated by the energy of light or heat or both, (A) a specific alkali-soluble resin having a polymerizable functional group, and (D) initiating polymerization of a radical polymerizable compound, Refers to the compound to be promoted. Here, “heat mode exposure” is in accordance with the definition in the present invention.
As the radical initiator, known photopolymerization initiators, thermal polymerization initiators and the like can be selected and used. However, in the present invention, an onium salt compound is selected and used from the viewpoint of high sensitivity. Yes.

  An onium salt that can be suitably used as a radical initiator in the present invention will be described. Preferable onium salts include 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 formula (V).

Wherein ^{(V), R 31, R} 32 and R ^33, which may be the same or different, 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 ^31- represents a perchlorate ion, a hexafluorophosphate ion, or an aryl sulfonate ion, and more preferably an aryl sulfonate ion.

  In the present invention, specific examples of onium salts that can be suitably used as a radical generator include those described in paragraph [0033] of Japanese Patent Application No. 11-310623.

Further, an onium salt represented by the general formula (II) described in paragraphs [0012] to [0050] of JP-A-9-34110 and a heat described in paragraph [0016] of JP-A-8-108621. A known polymerization initiator such as a polymerization initiator is also preferably used.
The radical initiator 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 image recording material can be handled under white light.

The lithographic printing plate precursor according to the invention further contains (D) a radical polymerizable compound for the purpose of improving image strength.
[(D) Radical polymerizable compound]
The radically polymerizable compound contained in the lithographic printing plate precursor according to the invention is a radically polymerizable compound having at least one ethylenically unsaturated double bond, and has at least one terminal ethylenically unsaturated bond, preferably 2 It is selected from compounds having at least one. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, unsaturated carboxylic acid ester having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group, amide and monofunctional or polyfunctional isocyanate, addition reaction product of epoxy, monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, halogen A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a group or a tosyloxy group with 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 or the like instead of the unsaturated carboxylic acid.

  Specific examples of the radical polymerizable compound that is 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, 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, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer, etc. is there.

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

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

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

  Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

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

  Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. Those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.

  Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

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

General formula (VI)
^{_{CH 2 = C (R 41)}} COOCH 2 CH (R 42) OH
(However, R ⁴¹ and R ⁴² represent H or CH _3. )

Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765, JP-B-58-49860, JP-B-56-17654, Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable.
Furthermore, radical 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 may be used.

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

(D) The radically polymerizable compounds may be used alone or in combination of two or more. For these radically polymerizable compounds, the details of how to use them, such as what structure to use, whether they are used alone or in combination, and how much they are added, can be selected according to the performance design of the final recording material. Can be set.
As for the compounding ratio of the radically polymerizable compound in the image recording material, a larger amount is advantageous in terms of sensitivity. However, if it is too large, undesirable phase separation may occur or the production process due to the adhesiveness of the image recording layer may occur. Problems (for example, transfer of recording layer components, manufacturing defects due to adhesion) and precipitation from the developer may occur. From these viewpoints, the preferable blending ratio of the radical polymerizable compound is often 5 to 80% by weight, preferably 20 to 75% by weight, based on the total components of the composition. In the present invention, when (D) another radical polymerizable compound is used in combination with the (A) specific alkali-soluble resin, the ratio of the component (A) to the component (D) is 1: 0.05 to the weight ratio. It is used in the range of 1: 3, preferably in the range of 1: 0.1 to 1: 2, more preferably in the range of 1: 0.3 to 1: 1.5.
As for the method of using the radically polymerizable compound, an appropriate structure, blending, and addition amount can be arbitrarily selected from desired properties, and in some cases, a layer configuration / coating method such as undercoating or overcoating can be carried out.

[Other ingredients]
In addition to these, various compounds may be added to the image recording material of the present invention as necessary. For example, a dye having a large absorption in the visible light region can be used as an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in No. 293247. In addition, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can also be suitably used.

  These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The amount added is 0.01 to 10% by weight based on the total solid content of the photosensitive layer coating solution.

  In the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during preparation or storage of the image recording material. 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), N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by weight to about 5% by weight with respect to the weight of the total composition. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition due to oxygen, and it may be unevenly distributed on the surface of the photosensitive layer in the course of drying after coating. . The amount of the higher fatty acid derivative added is preferably from about 0.1% to about 10% by weight of the total composition.

  The image recording material in the present invention is mainly used for forming an image recording layer of a lithographic printing plate precursor. In order to increase the processing stability of such an image recording layer with respect to development conditions, Japanese Patent Application Laid-Open No. Sho 62. Nonionic surfactants as described in JP-A Nos. 251740 and 3-208514, and amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149 are added. can do.

  Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like.

Specific examples of amphoteric surfactants include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N, N- Examples include betaine type (for example, trade name Amorgen K, manufactured by Dai-ichi Kogyo Co., Ltd.).
The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive layer coating solution is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

  Furthermore, in the photosensitive layer coating solution according to the present invention, a plasticizer is added as needed to impart flexibility of the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate and the like are used.

  In order to produce a lithographic printing plate precursor using the image recording material of the present invention, the constituent components of the image recording material are usually dissolved in a solvent together with the components necessary for the coating solution and coated on a suitable support. . Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, it is not limited to this. These solvents are used alone or in combination. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by weight.

The coating, the coating amount of the image recording layer on the support obtained after drying (solid content) may be varied according to the intended purpose, is preferably generally 0.5 to 5.0 g / m ² As for the lithographic printing plate precursor . Various methods can be used as the coating method, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the image recording layer decrease.

  In the image recording layer coating solution according to the present invention, a surfactant for improving the coating property, for example, a fluorosurfactant described in JP-A-62-170950 may be added. it can. A preferred addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the material of the entire photosensitive layer.

(Protective layer)
When the image recording material of the present invention is used for a lithographic printing plate precursor, it is usually preferable to provide a protective layer on the image recording layer containing the photopolymerizable composition in order to perform exposure in the air. The properties desired for such a protective layer include low permeability of low molecular compounds such as oxygen, good light transmission for exposure, excellent adhesion to the recording layer, and development after exposure. It is easy to remove in the process, and it is common to use water-soluble polymer compounds having relatively excellent crystallinity such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid. is there. As described above, the protective layer may be provided for the purpose of further enhancing oxygen barrier properties from the outside and enhancing image forming properties, particularly image strength.

(Support)
The support used when forming a lithographic printing plate precursor using the image recording material of the present invention is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, plastic (for example, , Polyethylene, polypropylene, polystyrene, etc., laminated paper, metal plates (eg, aluminum, zinc, copper, etc.), plastic films (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate) , Cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.). These may be a single component sheet such as a resin film or a metal plate, or may be a laminate of two or more materials. For example, a paper or plastic film on which a metal as described above is laminated or vapor-deposited. And laminated sheets of different plastic films.

As the support, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of different elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by weight. Particularly suitable aluminum in the present invention is pure aluminum. However, since completely pure aluminum is difficult to manufacture in terms of refining technology, it may contain slightly different elements. Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used.
The aluminum plate has a thickness of about 0.1 to 0.6 mm, preferably 0.15 to 0.4 mm, and particularly preferably 0.2 to 0.3 mm.

Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired.
The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.
The aluminum plate roughened in this way can be subjected to an anodizing treatment to enhance the water retention and wear resistance of the surface through an alkali etching treatment and a neutralization treatment, if desired. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, 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 electrolyte.

The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. dm ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are suitable.
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, or the non-image part of the lithographic printing plate is easily scratched, so that the ink adheres to the scratched part during printing. “Scratches and dirt” are likely to occur.
Such an anodic oxidation treatment is applied to the surface used for printing on the support of the lithographic printing plate, but an anodized film of 0.01 to 3 g / m ² is also formed on the back surface due to the back of the lines of electric force. It is common to form.

The hydrophilic treatment of the support surface is performed after the anodizing treatment, and conventionally known treatment methods are used. Such hydrophilization treatment is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are various alkali metal silicate methods (for example, sodium silicate aqueous solution). In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, disclosed in Japanese Patent Publication No. 36-22063 is potassium fluoride zirconate and U.S. Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid as described above is used.
Among these, a particularly preferred hydrophilic treatment in the present invention is a silicate treatment. The silicate treatment will be described below.

The anodized film of the aluminum plate subjected to the treatment as described above has an alkali metal silicate content of 0.1 to 30% by weight, preferably 0.5 to 10% by weight, and a pH at 25 ° C. of 10 to 13. It is immersed in a certain aqueous solution at, for example, 15 to 80 ° C. for 0.5 to 120 seconds. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution will gel, and if it is higher than 13.0, the oxide film will be dissolved. Examples of the alkali metal silicate used in the present invention include sodium silicate, potassium silicate, and lithium silicate. Examples of the hydroxide used to increase the pH of the alkali metal silicate aqueous solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or a group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Can be mentioned. Examples of 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 do. 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 weight, and a more preferable range is 0.05 to 5.0% by weight.
Since the hydrophilicity on the surface of the aluminum plate is further improved by the silicate treatment, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

A back coat is provided on the back surface of the support as necessary. As such a backcoat, a coating comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 A layer is preferably used.
Among these coating layers, silicon alkoxy compounds such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , and Si (OC ₄ H ₉ ) ₄ are available at a low price. The coating layer of the metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

  As described above, a lithographic printing plate precursor can be prepared from the image recording material of the present invention. This lithographic printing plate precursor can be recorded with an infrared laser. Thermal recording with an ultraviolet lamp or a thermal head is also possible. In the present invention, image exposure is preferably performed by a solid-state laser and a semiconductor laser that emit infrared rays having a wavelength of 760 nm to 1200 nm.

  After exposure with an infrared laser, the image recording material of the present invention is preferably developed with water or an alkaline aqueous solution.

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 phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine 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 developer in the developing tank for a long time is added to the developer by adding an aqueous solution (replenisher) that is the same as the developer or higher in alkali strength than the developer. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the plate. This replenishment method is also preferably applied in the present invention.

  Various surfactants, organic solvents, and the like can be added to the developer and the replenisher as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving the ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferred organic solvents include benzyl alcohol. Moreover, addition of polyethylene glycol or a derivative thereof, or polypropylene glycol or a derivative thereof is also preferable. In addition, non-reducing sugars such as arabit, sorbit and mannitol can be added.

  In addition, the developer and replenisher may contain an inorganic salt reducing agent such as hydroquinone, resorcin, sodium sulfite or sodium bisulfite, and organic carboxylic acid, antifoaming agent and hard water softening agent as necessary. It can also be added.

  The printing plate developed using the developer and replenisher described above is post-treated with a desensitizing solution containing washing water, a rinsing solution containing a surfactant and the like, gum arabic and starch derivatives. As the post-treatment when the image recording material of the present invention is used as a printing plate, these treatments can be used in various combinations.

In recent years, automatic developing machines for printing plate materials have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for conveying a printing plate material, processing liquid tanks and a spray device. Each processing liquid pumped up is sprayed from a spray nozzle for development processing. In addition, recently, a method is also known in which a printing plate material is dipped and conveyed in a processing liquid tank filled with the processing liquid by a submerged guide roll or the like. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like. In addition, the electrical conductivity can be detected by a sensor and replenished automatically.
In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.

The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to obtain a lithographic printing plate with a higher printing durability, a burning treatment is performed. Is given.
In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with surface liquid.

As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method of applying the printing plate by dipping in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.
In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry weight).
The lithographic printing plate coated with the surface-adjusting liquid is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor BP-1300 sold by Fuji Photo Film Co., Ltd.). . In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.

  The burned lithographic printing plate can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound or the like is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted.

  By such processing, the lithographic printing plate obtained from the image recording material of the present invention is applied to an offset printing machine or the like and used for printing a large number of sheets.

  Hereinafter, the present invention will be described in more detail with reference to synthesis examples, examples and comparative examples, but the present invention is not limited thereto.

(Examples 1-5)
[Create support]
A molten metal of JIS A1050 alloy containing 99.5% or more of aluminum and Fe 0.30%, Si 0.10%, Ti 0.02%, and Cu 0.013% was subjected to cleaning treatment and cast. In the cleaning process, a degassing process was performed to remove unnecessary gases such as hydrogen in the molten metal, and a ceramic tube filter process was performed. The casting method was a DC casting method. The solidified 500 mm thick ingot was chamfered 10 mm from the surface and homogenized at 550 ° C. for 10 hours so that the intermetallic compound would not become coarse. Next, after hot rolling at 400 ° C. and intermediate annealing at 500 ° C. for 60 seconds in a continuous annealing furnace, cold rolling was performed to obtain an aluminum rolled plate having a plate pressure of 0.30 mm. By controlling the roughness of the rolling roll, the centerline average surface roughness Ra after cold rolling was controlled to 0.2 μm. Then, it applied to the tension leveler in order to improve planarity.

Next, the surface treatment for making a lithographic printing plate support was performed.
First, in order to remove the rolling oil on the surface of the aluminum plate, degreasing treatment was carried out with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were carried out with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.

Next, in order to improve the adhesion between the support and the recording layer and to provide water retention to the non-image rear portion, a so-called graining treatment was performed to roughen the surface of the support. While maintaining an aqueous solution containing 1% nitric acid and 0.5% aluminum nitrate at 45 ° C. and flowing an aluminum web through the aqueous solution, an alternating waveform with a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect power supply cell Then, electrolytic graining was performed by giving an anode side electric quantity of 240 C / dm ² . Thereafter, etching treatment was performed with a 10% sodium aluminate aqueous solution at 50 ° C. for 30 seconds, and neutralization and smut removal treatment were performed with a 30% sulfuric acid aqueous solution at 50 ° C. for 30 seconds.

Furthermore, in order to improve wear resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodized film of 2.5 g / m ² by using a 20% sulfuric acid aqueous solution as an electrolyte at 35 ° C. and carrying out an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power feeding cell while carrying an aluminum web into the electrolyte. It was created.

Thereafter, silicate treatment was performed to ensure hydrophilicity as a non-image portion of the printing plate. The treatment was carried with a 1.5% aqueous solution of sodium silicate 3 maintained at 70 ° C. so that the contact time of the aluminum web was 15 seconds, and further washed with water. The adhesion amount of Si was 10 mg / m ² . Ra (center line surface roughness) of the support prepared as described above was 0.25 μm.

[Formation of photosensitive layer]
The following photosensitive layer coating solution (P-1) was prepared, applied to the aluminum support obtained as described above using a wire bar, and dried at 115 ° C. for 45 seconds using a hot air dryer. A layer was formed to obtain a lithographic printing plate precursor. The coating amount after drying was in the range of 1.2 to 1.3 g / m ² .
In addition, the high molecular compound used for the Example is specific alkali-soluble resin obtained by the said synthesis example.

<Photosensitive layer coating solution (P-1)>
Alkali-soluble resin: Component (A) (Compound described in Table 6, amount described in Table 6)
・ Radical polymerizable compound: Component (D)
(Compound described in Table 6, amount described in Table 6)
Infrared absorber “IR-6”: component (B) 0.08 g
・ Sulphonium salt “S-1”: component (C) 0.30 g
・ Victoria Pure Blue Naphthalenesulfonic Acid 0.04g
・ Fluorine-based surfactant 0.01g
(Megafuck F-176, manufactured by Dainippon Ink & Chemicals, Inc.)
・ Methyl ethyl ketone 9.0g
・ Methanol 10.0g
1-methoxy-2-propanol 8.0g

[exposure]
The resulting lithographic printing plate precursor was exposed with a Trend setter 3244VFS manufactured by Creo equipped with a water-cooled 40 W infrared semiconductor laser under the conditions of an output of 9 W, an outer drum rotation speed of 210 rpm, a plate surface energy of 100 mJ / cm ² , and a resolution of 2400 dpi.
[Development processing]
After the exposure, the film was developed using an automatic processor Stablon 900N manufactured by Fuji Photo Film Co., Ltd. As the developer, a 1: 1 water dilution of DN-3C manufactured by Fuji Photo Film Co., Ltd. was used for both the charging solution and the replenisher. The temperature of the developing bath was 30 ° C. As the finisher, a 1: 1 water dilution of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used.
[Evaluation of printing durability]
Next, printing was performed using a printing press Lislon manufactured by Komori Corporation. At this time, the number of sheets that can be printed while maintaining a sufficient ink density was measured visually to evaluate the printing durability. The results are also shown in Table 6 above.
From the results in Table 6, it can be seen that the lithographic printing plates of the examples using the image recording material of the present invention as the photosensitive layer achieved excellent printing durability. The obtained lithographic printing plate precursor was stored at 60 ° C. for 3 days and stored at 45 ° C. and humidity 75% RH for 3 days, followed by forced aging. Table 6 shows.

  From Table 6, the lithographic printing plate using the image recording material of the present invention as a photosensitive layer has no stain on the non-image area, excellent printing durability, and is resistant even after storage in a high temperature and high humidity environment. It was found that the printing property and the smearing property of the non-image area were not deteriorated and the stability over time was excellent.

Claims (7)

(A) a polymer compound having at least one group represented by the following general formula (1) to general formula (3) in the side chain, insoluble in water and soluble in an alkaline aqueous solution, (B) a photothermal conversion agent, (C) An onium salt compound that is represented by the following general formula (V), and (B) generates a radical by heat mode exposure of light having a wavelength that can be absorbed by the photothermal conversion agent, and (D) a radical polymerizable compound. A negative lithographic printing plate precursor for heat mode, characterized in that it can be recorded by heat mode exposure.

In the formula, R ^{1 to} R ¹¹ each independently represents a monovalent organic group. X and Y each independently represent an oxygen atom, a sulfur atom or —N—R ¹² , and Z represents an oxygen atom, a sulfur atom, —N—R ¹² or a phenylene group. R ¹² represents a hydrogen atom or a monovalent organic group.

In the formula (V), R ³¹ , R ³² and R ³³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Z ^31- represents a perchlorate ion, a hexafluorophosphate ion, or an aryl sulfonate ion. The negative lithographic printing plate precursor as claimed in claim 1, wherein the photothermal conversion agent (B) is an infrared absorbing dye. The lithographic printing plate precursor as claimed in claim 2, wherein the infrared absorbing pigment is a dye. The lithographic printing plate precursor as claimed in claim 3, wherein the dye is a cyanine pigment. The lithographic printing plate precursor as claimed in claim 4, wherein the cyanine dye is a compound represented by the following general formula (I).

In the general formula (I), X ¹ represents a halogen atom or X ² -L ¹ . Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² are bonded to each other to form a 5-membered ring or a 6-membered ring. Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group. Y ¹ and Y ² each independently represent a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ each independently represents a hydrocarbon group having 20 or less carbon atoms. R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. ^{Further, Z 1-represents} a counter anion. The (A) was produced by a production method in which one or more radically polymerizable compounds represented by the following general formula (12) were polymerized, and then a proton was extracted using a base and Z was eliminated. 6. The polymer compound having a group represented by the following general formula (1) in a side chain, insoluble in water and soluble in an aqueous alkali solution. 6. A negative lithographic printing plate precursor for heat mode as described in 1.

In the formula, R ^{1 to} R ³ each independently represents a monovalent organic group. X represents an oxygen atom, a sulfur atom, or —N—R ¹² , and R ¹² represents a hydrogen atom or a monovalent organic group.

In the formula, Z represents an anionic leaving group. Q represents an oxygen atom, -NH-, or -NR ¹⁴ - are expressed (wherein, R ¹⁴ represents an alkyl group which may have a substituent). R ¹³ represents a hydrogen atom or an alkyl group which may have a substituent. A represents a divalent organic linking group. X and R < ¹ > -R < ³ > are synonymous with X and R < ¹ > -R < ³ > in General formula (1). The negative lithographic printing plate precursor for heat mode according to any one of claims 1 to 6, wherein Z ^31- in the general formula (V) is an aryl sulfonate ion.