JP5265955B2 - Plane printing plate aluminum alloy plate, planographic printing plate support, planographic printing plate precursor, and method for producing planographic printing plate aluminum alloy plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum alloy plate for planographic printing with excellent resistance to dot-like stain and a manufacturing process thereof, and also to provide a support body for planographic printing using it and an original plate for planographic printing plate, especially an original plate for planographic printing plate which can be developed on-press. <P>SOLUTION: The aluminum alloy plate for planographic printing plate includes 0.08 to 0.45 mass% of Fe and 0.05 to 0.20 mass% of Si, the remainder being an aluminum alloy plate comprised of an obligatory impurity and Al, wherein an Fe-Al intermetallic compound being contained at 0.05% or less. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an aluminum alloy plate for a lithographic printing plate, a method for producing the same, a lithographic printing plate support using the same, and a lithographic printing plate precursor.

  Numerous studies have been conducted on computer-to-plate (CTP) systems that have made remarkable progress in recent years. Among them, as an aim to further streamline the process and solve the waste liquid treatment problem, lithographic printing plate precursors that can be mounted on a printing machine and printed without being developed after exposure have been studied, and various methods have been proposed. Yes.

  One method of eliminating the processing step is to mount the exposed lithographic printing plate precursor on the plate cylinder of the printing press, and supply dampening water and ink while rotating the plate cylinder to remove the lithographic printing plate precursor. There is a method called on-machine development that removes the image area. That is, the lithographic printing plate precursor is exposed to light and mounted on a printing machine as it is, and development processing is completed in a normal printing process. A lithographic printing plate precursor suitable for on-press development has an image recording layer that is soluble in fountain solution or an ink solvent, and is bright when developed on a press in a bright room. It is required to have room handling properties.

  For example, Patent Document 1 describes a lithographic printing plate precursor in which a photosensitive layer in which fine particles of a thermoplastic hydrophobic polymer are dispersed in a hydrophilic binder polymer is provided on a hydrophilic support. In this Patent Document 1, a lithographic printing plate precursor is subjected to laser exposure, and the thermoplastic hydrophobic polymer particles in the image recording layer are coalesced by heat to form an image, and then the plate is mounted on a plate cylinder of a printing press, It is described that an unexposed portion can be removed (on-press development) with fountain solution and / or ink. This lithographic printing plate precursor also has suitability for handling a bright room because the photosensitive region is an infrared region.

  Patent Document 2 discloses a lithographic printing plate having an image recording layer containing at least one of thermoplastic polymer fine particles, polymer fine particles having a thermoreactive group, and microcapsules encapsulating a compound having a thermoreactive group. It is described that the original plate has good on-press developability, high sensitivity and high printing resistance.

  However, the lithographic printing plate precursors described in Patent Documents 1 and 2 have spots where ink tends to adhere to a part of the surface of the non-image area when stored for a long period of time, and appear on printed paper or the like. Alternatively, annular dirt (hereinafter also referred to as “pot-like dirt”) may occur.

Japanese Patent No. 2938397 JP 2001-293971 A

The present inventor examined the cause of the occurrence of this spot-like stain. First, the so-called on-press development type lithographic printing plate precursor described in Patent Documents 1 and 2, etc. is obtained by using printing ink and / or fountain solution. Since a removable image recording layer is provided, there are many hydrophilic components in the image recording layer. As a result, the image recording layer easily contains moisture due to the influence of outside air or the like. Focused on being. And so-called on-press development type lithographic printing plate precursors described in Patent Documents 1 and 2, etc., include moisture contained in the image recording layer due to the influence of outside air, etc., and hydrophilic components anionized by the moisture (hereinafter, It was clarified that the presence of the “anion”) caused corrosion of the aluminum alloy plate, thereby causing spot-like soiling.
Further, the present inventors, among anions, anions and / or PF ₆ consisting halide ions ^- presence of, was revealed that tends to cause corrosion of the aluminum alloy plate.

On the other hand, regarding the intermetallic compound of the aluminum alloy plate, for example, JP 2005-330588 A, JP 2005-232596 A, JP 11-151870 A and the like are included in an aluminum alloy plate for a lithographic printing plate. Contents related to intermetallic compounds are described.
Specifically, the Al-Fe intermetallic compound is likely to be a starting point of pits during electrolytic surface roughening than the Al-Fe-Si intermetallic compound, and among the Al-Fe intermetallic compounds, It is described that a metastable phase Al—Fe-based intermetallic compound tends to be a starting point of pits. JP-A-2005-330588 discloses that the number of metastable phase particles having a Fe / Al ratio of 0.6 or less is 0.35 or more with respect to the total number of intermetallic compound particles. It is described that eyes form. Furthermore, Japanese Patent Application Laid-Open No. 2005-232596 describes an aluminum alloy plate containing 0.5 to 2.0% of an average AlFe-based crystal precipitate. Japanese Patent Laid-Open No. 11-151870 is characterized in that the ratio of the number of Al—Fe intermetallic compound particles / the number of Al—Fe—Si intermetallic compound particles is 0.7 or more.
However, these patent documents do not describe an intermetallic compound for suppressing corrosion of the aluminum substrate by the image recording layer.

  Accordingly, the present invention relates to an aluminum alloy plate for a lithographic printing plate capable of obtaining a lithographic printing plate excellent in pot-like stain resistance, a method for producing the same, and a lithographic printing plate support and a lithographic printing plate precursor using the same. In particular, an object of the present invention is to provide a lithographic printing plate precursor which can be developed on-press.

As a result of earnest research to achieve the above object, the present inventor uses an aluminum alloy plate for a lithographic printing plate having a specific content of Si and Fe and a specific content of an Al—Fe intermetallic compound. Thus, it was found that a lithographic printing plate having excellent resistance to pot-like stains can be obtained, and the present invention has been completed.
That is, the present invention provides the following (1) to ( 11 ).

(1) An aluminum alloy plate containing 0.08 to 0.45% by mass of Fe, 0.05 to 0.20% by mass of Si, and the balance consisting of inevitable impurities and Al,
Der content is more than 0.05 mass% of Al-Fe intermetallic compound is,
An aluminum alloy plate for a lithographic printing plate , wherein a main component of an intermetallic compound present in the aluminum alloy plate is α-AlFeSi .

( 2 ) The aluminum alloy plate for lithographic printing plates as described in said (1 ) whose ratio (Fe / Si) of Fe content and Si content of the said aluminum alloy is 0.5-2.2.

( 3 ) The aluminum alloy plate for lithographic printing plates as described in said (1) or (2) whose Zn content is 0.01 mass% or less.

( 4 ) The aluminum alloy plate for a lithographic printing plate according to any one of (1) to ( 3 ), wherein the Mg content is 0.20% by mass or less.

( 5 ) A method for producing an aluminum alloy plate for a lithographic printing plate for producing an aluminum alloy plate for a lithographic printing plate according to any one of (1) to ( 4 ) above,
A semi-continuous casting process for forming an ingot from molten aluminum alloy;
A chamfering step for chamfering the ingot obtained in the semi-continuous casting step;
A method for producing an aluminum alloy plate for a lithographic printing plate, comprising: a soaking treatment in which a soaking treatment is performed in a temperature range of 500 to 550 ° C after the chamfering step.

( 6 ) A method for producing an aluminum alloy plate for a lithographic printing plate for producing an aluminum alloy plate for a lithographic printing plate according to any one of (1) to ( 4 ) above,
A continuous casting step of forming an aluminum alloy sheet by rolling while solidifying the molten aluminum alloy;
A cold rolling step for reducing the thickness of the aluminum alloy plate obtained in the continuous casting step;
After the cold rolling step, an intermediate annealing step in which heat treatment is performed at a temperature of 500 ° C. or lower,
A method for producing an aluminum alloy plate for a lithographic printing plate, comprising: a finish cold rolling step for reducing the thickness of the aluminum alloy plate after the intermediate annealing.

( 7 ) The surface of the aluminum alloy plate for lithographic printing plates according to any one of the above (1) to ( 4 ) is subjected to roughening treatment including electrochemical roughening treatment and anodizing treatment in this order. A support for a lithographic printing plate obtained.

( 8 ) A lithographic printing plate support obtained by further hydrophilizing after the anodizing treatment,
The support for a lithographic printing plate as described in ( 7 ) above, wherein the hydrophilization treatment is a treatment using an alkali metal silicate so that the adsorption amount of silicon is 1.0 to 30 mg / m ² .

( 9 ) A lithographic printing plate precursor comprising an image recording layer provided on the lithographic printing plate support described in ( 7 ) or ( 8 ) above.

(10) The image recording layer is anionic and / or PF ₆ consisting halide ions ^- The lithographic printing plate precursor as described in (9) having a.

( 11 ) The lithographic plate according to the above ( 9 ) or ( 10 ), wherein the image recording layer is an image recording layer that forms an image by exposure and the non-exposed portion can be removed by printing ink and / or fountain solution. A printing plate master.

As will be described below, according to the present invention, an aluminum alloy plate for a lithographic printing plate capable of obtaining a lithographic printing plate excellent in pot-like stain resistance, a method for producing the same, and a lithographic printing plate using the same A support and a lithographic printing plate precursor, particularly a lithographic printing plate precursor capable of on-press development can be provided.
Further, according to the present invention, the anion concentration in the image recording layer (halide ion concentration, PF ₆ ^- concentration) without being affected by, since it is possible to obtain a lithographic printing plate having excellent resistance to spotting, very useful It is.

Hereinafter, the present invention will be described in detail.
[Support for lithographic printing plate]
<Aluminum alloy plate (rolled aluminum)>
For the lithographic printing plate support of the present invention, the aluminum alloy plate for lithographic printing plates of the present invention described below (hereinafter also referred to as “the aluminum alloy plate of the present invention”) is used.
The essential alloy components in the aluminum alloy plate of the present invention are Al, Fe and Si.

  Fe has an effect of increasing the mechanical strength of the aluminum alloy, and greatly affects the strength of the support for a lithographic printing plate. If the Fe content is too small, the mechanical strength is too low, and plate breakage is likely to occur when the lithographic printing plate is attached to the plate cylinder of a printing press. Further, when printing a large number of copies at high speed, the plate is likely to be cut out similarly. On the other hand, when the content of Fe is too large, the strength becomes higher than necessary, and when the lithographic printing plate is attached to the plate cylinder of a printing press, the fitness is inferior, and the plate is easily cut during printing.

In the present invention, the Fe content is 0.08 to 0.45 mass%, and preferably 0.08 to 0.35 mass%.
When the Fe content is within this range, the strength is not unnecessarily high, the fitness is excellent when a lithographic printing plate is attached to the plate cylinder of a printing press, and plate breakage during printing can be prevented.

Fe forms an Al—Fe based intermetallic compound and an Al—Fe—Si based intermetallic compound.
Here, as described above, the Al—Fe-based intermetallic compound has higher electrochemical solubility than the Al—Fe—Si-based intermetallic compound, and has a strong effect as a starting point of pits. In addition, the Al-Fe-based intermetallic compound is more likely to be a pit starting point than the Al-Fe-Si-based intermetallic compound, and among the Al-Fe-based intermetallic compounds, the Al-Fe-based metal is more metastable than the stable layer. Intermetallic compounds are likely to be pit starting points.

In the present invention, the content of the Al—Fe-based intermetallic compound is 0.05% by mass or less, preferably 0.02% by mass or less, and more preferably 0.015% by mass or less.
When the content of the Al—Fe-based intermetallic compound is within this range, the spot-like stain resistance of the lithographic printing plate using the aluminum alloy plate of the present invention obtained is excellent. As described above, this is based on the new finding that when the image recording layer contains many hydrophilic components, the Al—Fe-based intermetallic compound is a starting point for corrosion of the aluminum alloy plate.
In the present invention, the content of the Al—Fe-based intermetallic compound is calculated by the following formula.

  Al-Fe intermetallic compound content (% by mass) = {Fe content (% by mass) -Fe solid solution amount (% by mass)} × {(Al—Fe intermetallic compound phase peak detected by XRD Sum of integral diffraction intensities) / (total sum of integral diffraction intensities of Fe phase peaks detected by XRD)}

Here, the Al—Fe-based intermetallic compound indicates Al ₃ Fe and Al ₆ Fe, and the Fe-based phases indicate Al ₃ Fe, Al ₆ Fe, and α-AlFeSi.

The integrated diffraction intensity by XRD was measured under the following conditions by setting an aluminum alloy plate on an X-ray diffractometer RAD-rR (12 kW rotating counter-cathode type, manufactured by Rigaku Corporation), and detected Fe-based intermetallic compound. This is a value obtained by calculating an integrated diffraction intensity value (unit: Kcounts) of a peak representative of the phase (Al ₃ Fe, Al ₆ Fe, α-AlFeSi). When no peak appeared, the integrated diffraction intensity was calculated as 0.1.
・ Set tube voltage 50kV
・ Set tube current 200mA
・ Sampling interval 0.01 °
・ Scanning speed 1 ° / min ・ 2θ scanning range 10 ° ～ 70 °
・ Use of graphite monochromator

  In addition, the Fe solid solution amount is obtained by dissolving the aluminum alloy plate with hot phenol, filtering the dissolved matrix and the intermetallic compound as a residual residue, and further adding 10% citric acid to the fine intermetallic compound in the filtrate. It is the value which isolate | separated by extraction using a solution and measured the amount of Fe in the subsequent filtrate with the ICP emission spectrometer.

Si exists as a solid solution in aluminum, or forms a precipitate of an Al—Fe—Si intermetallic compound or Si alone.
Si dissolved in aluminum has an action of making the electrochemical rough surface uniform and an action of making the depth of the pit generated by the electrochemical roughening treatment mainly deep and uniform.

  Here, Si is contained as an inevitable impurity in the Al ingot, which is a raw material, and is often intentionally added in a small amount in order to prevent variations due to differences in raw materials. At that time, if the Si content is less than 0.05% by mass, the above effect does not appear, and a high-purity Al metal is necessary and expensive, which is not practical. Conversely, if the Si content exceeds 0.20% by mass, there is a problem that the spot-like stains are deteriorated when printing is performed. On the other hand, some raw materials may already have a content of 0.03% by mass or more, and therefore a numerical value less than 0.03% by mass is not realistic.

In the present invention, the content of Si is 0.05 to 0.20% by mass.
When the Si content is within this range, the uniformity of the electrochemical surface-roughening treatment described later is not impaired, and the lithographic printing plate using the obtained aluminum alloy plate of the present invention has a pot-like stain resistance. Is excellent.

As described above, the present inventor has found that the Al—Fe-based intermetallic compound is a starting point of corrosion of the aluminum alloy plate, and at the same time, the Al—Fe—Si intermetallic compound and the Si single precipitate are Al. It has been found that it is less likely to be a starting point for corrosion of an aluminum alloy sheet as compared to an Fe-based intermetallic compound.
Therefore, in the present invention, the main component of the intermetallic compounds of the aluminum alloy plate, an A l-Fe-Si-based intermetallic compound alpha-AlFeSi Ru der. Here, a main component means the component which contains most among intermetallic compounds, and it is preferable that it is more than 50 mass%.
In this way, in order to increase the precipitation amount of the Al—Fe—Si intermetallic compound, as shown in the method for producing an aluminum alloy plate of the present invention described later, the ingot formed from the molten aluminum alloy is subjected to face cutting. After that, it is preferable to perform soaking in a temperature range of 500 to 550 ° C.

Moreover, in this invention, mass ratio (Fe / Si) of Fe content and Si content is 0.5-2.2, It is preferable that it is 0.5-1.4, 1.0 More preferably, it is -1.4.
When the ratio of Fe content to Si content (Fe / Si) in the aluminum alloy plate is within this range, the Al-Fe-Si intermetallic compound increases, and the resulting corrosion in the aluminum alloy plate of the present invention As a result, the spot-like stain resistance of the lithographic printing plate is further improved.

Zn has the effect of reducing the diameter of the pits generated by the electrochemical surface roughening treatment, and can be added to design a desired pit shape. If a large amount is added, the pit diameter can be reduced.
In the present invention, the Zn content is preferably 0.01% by mass or less.

Mg has the effect of refining the recrystallized structure of Al, and the effect of improving mechanical strength such as tensile strength, yield strength, fatigue strength, bending strength, and heat softening resistance.
Moreover, Mg has the effect | action which makes the dispersion | distribution of the pit at the time of an electrolytic roughening uniform by adding a suitable quantity.
In the present invention, the Mg content is preferably 0.20% by mass or less.

Cu is an element that is relatively easily dissolved in aluminum and has a great influence on the electrochemical surface roughening properties of the lithographic printing plate support.
In the present invention, Cu may be appropriately contained in the range of 0.001 to 0.040% by mass.

The balance of the aluminum alloy plate is made of Al and inevitable impurities.
Examples of the inevitable impurities include Mn, Cr, Zr, V, and Be, and these may be contained in an amount of 0.05% by mass or less.
Moreover, most of inevitable impurities are contained in the Al ingot. For example, if the inevitable impurities are contained in a metal having an Al purity of 99.5%, the effects of the present invention are not impaired.
For inevitable impurities, see, for example, L.A. F. The amount of impurities described in Mondolfo's “Aluminum Alloys: Structure and properties” (1976) and the like may be contained.

<Method for producing aluminum alloy plate>
The above-described aluminum alloy plate of the present invention can be produced, for example, by performing the following treatments.

(Cleaning treatment)
First, a molten aluminum alloy adjusted to a predetermined alloy component content can be subjected to a cleaning treatment as necessary according to a conventional method.
Examples of the cleaning treatment include degassing treatment for removing unnecessary gases such as hydrogen in the molten metal (eg flux treatment using argon gas, chlorine gas, etc.); ceramic tube filter, ceramic foam filter, etc. A filtering process using a so-called rigid media filter, a filter using alumina flakes, alumina balls, or the like as a filter medium, a glass cloth filter, or the like; a process in which such a degassing process and a filtering process are combined;

(Casting process)
Next, casting is performed using a molten aluminum alloy that has been subjected to a cleaning treatment as necessary.
Examples of the casting method include a casting method using a fixed mold represented by a semi-continuous casting method, a casting method using a driving mold represented by a continuous casting method, and the like.

In the semi-continuous casting method, for example, an ingot having a desired plate thickness (for example, 300 to 800 mm) is manufactured using a fixed mold. Thereafter, the obtained ingot is chamfered according to a conventional method, and a surface layer of 1 to 30 mm, preferably 1 to 10 mm, is cut to obtain an aluminum alloy plate having a desired plate thickness. be able to.
On the other hand, in the continuous casting method, for example, an aluminum alloy molten metal having a desired thickness can be obtained by inserting a molten aluminum alloy between a pair of twin belts.

(Heat treatment)
In the present invention, the aluminum alloy plate obtained by casting is preferably heated to the temperature of hot rolling by heat treatment in order to be subjected to hot rolling.

(Soaking)
Further, in the present invention, when the casting process is performed by the semi-continuous casting method, it is preferable that a soaking process is performed between the heat treatment and the hot rolling process, which is held at a predetermined temperature for a predetermined time.

The soaking process is preferably maintained in a temperature range of 500 to 550 ° C. from the viewpoint of not coarsening the intermetallic compound and depositing an Al—Fe—Si intermetallic compound, and a temperature range of 500 to 540 ° C. Is more preferable, and the temperature range of 510-540 degreeC is still more preferable. When the temperature range of the soaking is within this range, precipitation of Al—Fe-based intermetallic compounds such as Al ₃ Fe is suppressed.
Moreover, it is preferable to perform the said soaking process by hold | maintaining for 1 to 48 hours in the said temperature range.
Note that when the casting process is performed by the continuous casting method, the solidification rate in casting is high and the precipitation of the Al—Fe—Si intermetallic compound is large, so that it is not necessary to perform the soaking process.

(Rolling treatment)
If the soaking process is performed after the casting process or if desired, the aluminum alloy plate-like body after the soaking process is subjected to hot rolling or cold rolling as necessary, and finally a predetermined thickness, for example, To a thickness of 0.1 to 0.5 mm.
The rolling of the plate-like body can be performed by inserting the plate-like body between a pair of rolls. The starting temperature of hot rolling is preferably 350 to 500 ° C.
In the case of the continuous casting method, it is preferable to perform cold rolling and intermediate annealing at 500 ° C. or lower after continuous casting. By setting the temperature of the intermediate annealing to 500 ° C. or less, precipitation of Al—Fe-based intermetallic compounds such as Al ₃ Fe is suppressed.

The flatness of the aluminum alloy plate finished to a predetermined thickness (for example, 0.1 to 0.5 mm) by the above processing may be further improved by a correction device such as a roller leveler or a tension leveler.
The flatness may be improved after the aluminum alloy plate is cut into a sheet shape, but it is preferably performed in a continuous coil state in order to improve productivity.
Further, a slitter line may be used for processing into a predetermined plate width.
Furthermore, in order to prevent generation | occurrence | production of the damage | wound by friction between aluminum alloy plates, you may provide a thin oil film on the surface of an aluminum alloy plate. As the oil film, a volatile or non-volatile film is appropriately used as necessary.

The method for producing an aluminum alloy plate for a lithographic printing plate of the present invention for producing the aluminum alloy plate of the present invention (hereinafter also referred to as “the method for producing an aluminum alloy plate of the present invention”) includes the above-mentioned treatments,
A semi-continuous casting process for forming an ingot from molten aluminum alloy;
A chamfering step for chamfering the ingot obtained in the semi-continuous casting step;
It is preferable that after the chamfering step, a soaking treatment step of soaking in a temperature range of 500 to 550 ° C.

On the other hand, the manufacturing method of the aluminum alloy plate of the present invention includes the above-described processes.
A continuous casting step of forming an aluminum alloy sheet by rolling while solidifying the molten aluminum alloy;
A cold rolling step for reducing the thickness of the aluminum alloy plate obtained in the continuous casting step;
After the cold rolling step, an intermediate annealing step in which heat treatment is performed at a temperature of 500 ° C. or lower,
It is preferable that the method comprises a finish cold rolling step for reducing the thickness of the aluminum alloy sheet after the intermediate annealing.

<Roughening treatment>
The lithographic printing plate support of the present invention is obtained by subjecting the surface of the aluminum alloy plate described above to a roughening treatment including an electrochemical roughening treatment.

The surface roughening treatment may be performed only by electrochemical surface roughening treatment, but may be performed by combining electrochemical surface roughening treatment with mechanical surface roughening treatment and / or chemical surface roughening treatment. Also good.
When the mechanical surface roughening treatment and the electrochemical surface roughening treatment are combined, it is preferable to perform the electrochemical surface roughening treatment after the mechanical surface roughening treatment.

  In the present invention, the electrochemical surface roughening treatment is preferably performed in an aqueous solution of nitric acid or hydrochloric acid.

The mechanical surface roughening treatment is performed for the purpose of making the surface of the aluminum alloy plate generally have a surface roughness _{Ra of} 0.35 to 1.0 μm, if desired.
In the present invention, the conditions for the mechanical surface roughening treatment are not particularly limited, but can be applied according to the method described in Japanese Patent Publication No. 50-40047. The mechanical surface roughening treatment can be performed by brush grain processing using a pumiston suspension or can be performed by a transfer method.
Further, the chemical surface roughening treatment is not particularly limited, and can be performed according to a known method.

After the mechanical surface roughening treatment, the following chemical etching treatment is preferably performed.
The chemical etching process that is performed after the mechanical roughening process smooths the uneven edges on the surface of the aluminum alloy plate, prevents ink from being caught during printing, and improves the stain resistance of the lithographic printing plate And removing unnecessary substances such as abrasive particles remaining on the surface.
As the chemical etching treatment, acid etching or alkali etching is known, but as a method that is particularly excellent in terms of etching efficiency, chemical etching treatment using an alkaline solution (hereinafter also referred to as “alkali etching treatment”). ).

The alkaline agent used in the alkaline solution is not particularly limited, and preferred examples include caustic soda, caustic potash, sodium metasilicate, sodium carbonate, sodium aluminate, and sodium gluconate.
Each alkaline agent may contain aluminum ions. The concentration of the alkaline solution is preferably 0.01% by mass or more, more preferably 3% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less. preferable.
Furthermore, the temperature of the alkaline solution is preferably room temperature or higher, more preferably 30 ° C. or higher, preferably 80 ° C. or lower, and more preferably 75 ° C. or lower.

The etching amount is preferably 0.1 g / m ² or more, more preferably 1 g / m ² or more, more preferably 20 g / m ² or less, and 10 g / m ² or less. Is more preferable.
The treatment time is preferably 2 seconds to 5 minutes corresponding to the etching amount, and more preferably 2 to 10 seconds from the viewpoint of improving productivity.

In the present invention, when an alkali etching treatment is performed after the mechanical surface roughening treatment, a chemical etching treatment (hereinafter referred to as “desmut treatment”) is performed using a low-temperature acidic solution in order to remove products generated by the alkali etching treatment. It is also preferable to apply.
Although the acid used for an acidic solution is not specifically limited, For example, a sulfuric acid, nitric acid, and hydrochloric acid are mentioned. The concentration of the acidic solution is preferably 1 to 50% by mass. Moreover, it is preferable that the temperature of an acidic solution is 20-80 degreeC. When the concentration and temperature of the acidic solution are within this range, the spot-like stain resistance of the lithographic printing plate using the obtained lithographic printing plate support of the present invention is further improved.

  In the present invention, the roughening process is a process of applying an electrochemical roughening process after performing a mechanical roughening process and a chemical etching process as desired. Even when the electrochemical surface roughening treatment is performed without performing the chemical surface roughening treatment, the chemical etching treatment can be performed using an alkaline aqueous solution such as caustic soda before the electrochemical surface roughening treatment. Thereby, impurities etc. existing in the vicinity of the surface of the aluminum alloy plate can be removed.

The electrochemical roughening treatment is suitable for making a lithographic printing plate having excellent printability because it is easy to impart fine irregularities (pits) to the surface of the aluminum alloy plate.
The electrochemical surface roughening treatment is performed using direct current or alternating current in an aqueous solution mainly composed of nitric acid or hydrochloric acid.

  By the electrochemical surface roughening treatment, crater-like or honeycomb-like pits having an average diameter of about 0.5 to 20 μm can be generated at an area ratio of 30 to 100% on the surface of the aluminum alloy plate. The pits having an appropriate property have the effect of improving the severe stain resistance and printing durability of the lithographic printing plate. In the lithographic printing plate support of the present invention, the conditions for this electrochemical surface roughening treatment are not particularly limited and can be performed under general conditions.

  Moreover, it is preferable to perform the following chemical etching process after an electrochemical roughening process. Smut and intermetallic compounds exist on the surface of the aluminum alloy plate after the electrochemical surface roughening treatment. In the chemical etching process performed after the electrochemical surface roughening process, it is preferable to first perform a chemical etching process (alkali etching process) using an alkaline solution in order to efficiently remove smut. Regarding various conditions of the chemical etching treatment using an alkaline solution, the treatment temperature is preferably 20 to 80 ° C., and the treatment time is preferably 1 to 60 seconds. Moreover, it is preferable to contain aluminum ion in an alkaline solution.

Furthermore, after the electrochemical surface roughening treatment, a chemical etching treatment using an alkaline solution is performed, and then a chemical etching treatment (desmut treatment) is performed using a low-temperature acidic solution in order to remove the resulting products. Is preferred.
Regarding various conditions of the desmut treatment, the treatment temperature is preferably 20 to 80 ° C., and the treatment time is preferably 1 to 60 seconds. As the acidic solution, a liquid mainly composed of nitric acid, hydrochloric acid, sulfuric acid or the like is used.

Even when the alkali etching treatment is not performed after the electrochemical surface roughening treatment, it is preferable to perform a desmut treatment in order to efficiently remove the smut.
Regarding various conditions of the desmut treatment, the treatment temperature is preferably 20 to 80 ° C., and the treatment time is preferably 1 to 60 seconds. As the acidic solution, a liquid mainly composed of nitric acid, hydrochloric acid, sulfuric acid or the like is used, and among them, a liquid mainly composed of hydrochloric acid is preferable.

  In the present invention, any of the above-described chemical etching treatments can be performed by a dipping method, a shower method, a coating method, or the like, and is not particularly limited.

<Anodizing treatment>
The lithographic printing plate support of the present invention is obtained by subjecting it to a roughening treatment and then an anodic oxidation treatment.
The electrolyte used for the anodizing treatment is not particularly limited as long as it can form a porous oxide film, and generally sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixture thereof is used. .
The concentration of the electrolyte is appropriately determined depending on the type of electrolyte.
Furthermore, the conditions for the anodizing treatment are not particularly limited because they vary considerably depending on the electrolyte. In general, the concentration of the electrolyte is 1 to 80% by mass, the liquid temperature is 5 to 70 ° C., the current density is 1 to 60 A / dm ² , The voltage may be 1 to 100 V and the electrolysis time may be 10 to 300 seconds.

<Hydrophilic treatment>
The lithographic printing plate support of the present invention is preferably obtained by subjecting it to a hydrophilization treatment after anodizing treatment.
Examples of the hydrophilization treatment include treatment with potassium fluorinated zirconate described in US Pat. No. 2,946,638 and phosphomolybdate described in US Pat. No. 3,201,247. Treatment, alkyl titanate treatment described in British Patent 1,108,559, polyacrylic acid treatment described in German Patent 1,091,433, German Patent 1,134, No. 093 and British Patent No. 1,230,447, polyvinylphosphonic acid treatment, Japanese Patent Publication No. 44-6409, phosphonic acid treatment, US Pat. No. 3,307,951 Phytic acid treatment described in the specification of JP, No. 58-16893 and JP-A No. 58-18291 Treatment with a salt of a molecular compound and a divalent metal, as described in US Pat. No. 3,860,426, hydrophilic cellulose (eg, zinc acetate) containing a water-soluble metal salt (eg, zinc acetate) Carboxymethyl cellulose) is provided with a subbing layer, and a water-soluble polymer having a sulfo group described in JP-A-59-101651.

Further, phosphates described in JP-A No. 62-019494, water-soluble epoxy compounds described in JP-A No. 62-033692, and JP-A No. 62-097892 Phosphate-modified starch, diamine compounds described in JP-A-63-056498, amino acid inorganic or organic acids described in JP-A-63-130391, JP-A-63-145092 Organic phosphonic acids containing carboxy group or hydroxy group, compounds having amino group and phosphonic acid group described in JP-A-63-165183, and JP-A-2-316290 Specific carboxylic acid derivatives, phosphate esters described in JP-A-3-215095, JP-A-3-261592 Compounds having one amino group and one oxygen acid group of phosphorus described in the publication, phosphoric esters described in JP-A-3-215095, and JP-A-5-246171 Aliphatic or aromatic phosphonic acids such as phenylphosphonic acid, compounds containing S atoms such as thiosalicylic acid described in JP-A-1-307745, and phosphorus described in JP-A-4-282737 Examples of the treatment include undercoating using a compound having a group of oxygen acids.
Further, coloring with an acid dye described in JP-A-60-64352 can also be performed.

  Hydrophilicity can also be achieved by soaking in an aqueous solution of an alkali metal silicate such as sodium silicate or potassium silicate, or by applying a hydrophilic vinyl polymer or hydrophilic compound to form a hydrophilic primer layer. It is preferable to carry out the treatment.

Hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. It can be performed according to methods and procedures.
Examples of the alkali metal silicate include sodium silicate, potassium silicate, and lithium silicate. The aqueous solution of alkali metal silicate may contain an appropriate amount of sodium hydroxide, potassium hydroxide, lithium hydroxide or the like.
The aqueous solution of alkali metal silicate may contain an alkaline earth metal salt or a Group 4 (Group IVA) metal salt. Examples of the alkaline earth metal salt include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate; sulfates; hydrochlorides; phosphates; acetates; oxalates; Examples of Group 4 (Group IVA) metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride. And zirconium tetrachloride. These alkaline earth metal salts and Group 4 (Group IVA) metal salts are used alone or in combination of two or more.

The amount of Si adsorbed by the alkali metal silicate treatment can be measured with a fluorescent X-ray analyzer, and the amount adsorbed is preferably 1.0 to 30 mg / m ² .
By this alkali metal silicate treatment, the effect of improving the dissolution resistance to the alkaline developer on the surface of the lithographic printing plate support is obtained, the dissolution of the aluminum component into the developer is suppressed, and the developer fatigue It is possible to reduce the occurrence of development residue due to the above.

The hydrophilization treatment by forming a hydrophilic undercoat layer can also be performed according to the conditions and procedures described in JP-A Nos. 59-101651 and 60-149491.
Examples of the hydrophilic vinyl polymer used in this method include polyvinyl sulfonic acid, sulfo group-containing vinyl polymerizable compounds such as p-styrene sulfonic acid having a sulfo group, and ordinary vinyl polymerization such as (meth) acrylic acid alkyl ester. And a copolymer with a functional compound. Examples of hydrophilic compounds that may be used in this method include, -NH ₂ group, compounds having at least one selected from the group consisting of -COOH group and sulfo group.

  On the other hand, in this invention, it is preferable that it is the support for lithographic printing plates obtained by giving each process shown to the following AC aspects to the aluminum alloy plate mentioned above in the order shown below. In addition, it is desirable to perform water washing between the following processes. However, when two steps (processes) to be performed in succession use a liquid having the same composition, washing with water may be omitted.

(A mode)
(1) Mechanical roughening treatment (2) Chemical etching treatment in alkaline aqueous solution (first alkali etching treatment)
(3) Chemical etching treatment in acidic aqueous solution (first desmutting treatment)
(4) Electrochemical roughening treatment in an aqueous solution mainly composed of nitric acid (first electrochemical roughening treatment)
(5) Chemical etching treatment in an aqueous alkali solution (second alkali etching treatment)
(6) Chemical etching treatment in acidic aqueous solution (second desmut treatment)
(7) Electrochemical roughening treatment in an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment)
(8) Chemical etching treatment in an alkaline aqueous solution (third alkali etching treatment)
(9) Chemical etching treatment in acidic aqueous solution (third desmut treatment)
(10) Anodizing treatment (11) Hydrophilization treatment

(B mode)
(2) Chemical etching treatment in alkaline aqueous solution (first alkali etching treatment)
(3) Chemical etching treatment in acidic aqueous solution (first desmutting treatment)
(12) Electrochemical roughening treatment in an aqueous solution mainly composed of hydrochloric acid (5) Chemical etching treatment in an aqueous alkali solution (second alkali etching treatment)
(6) Chemical etching treatment in acidic aqueous solution (second desmut treatment)
(10) Anodizing treatment (11) Hydrophilization treatment

(C mode)
(2) Chemical etching treatment in alkaline aqueous solution (first alkali etching treatment)
(3) Chemical etching treatment in acidic aqueous solution (first desmutting treatment)
(4) Electrochemical roughening treatment in an aqueous solution mainly composed of nitric acid (first electrochemical roughening treatment)
(5) Chemical etching treatment in an aqueous alkali solution (second alkali etching treatment)
(6) Chemical etching treatment in acidic aqueous solution (second desmut treatment)
(7) Electrochemical roughening treatment in an aqueous solution mainly composed of hydrochloric acid (second electrochemical roughening treatment)
(8) Chemical etching treatment in an alkaline aqueous solution (third alkali etching treatment)
(9) Chemical etching treatment in acidic aqueous solution (third desmut treatment)
(10) Anodizing treatment (11) Hydrophilization treatment

Here, the mechanical surface roughening treatment, electrochemical surface roughening treatment, chemical etching treatment, anodizing treatment and hydrophilization treatment in the above (1) to (12) are the same as the above-described treatment methods and conditions. However, the treatment is preferably performed under the treatment method and conditions described below.
In order to form a pit shape peculiar to the lithographic printing plate support of the present invention, an electrochemical roughening treatment is performed in an aqueous nitric acid solution described below, and then an electrochemical roughening in an aqueous hydrochloric acid solution. It is necessary to perform surface treatment.

The mechanical roughening treatment is preferably mechanically roughened with a rotating nylon brush roll having a bristle diameter of 0.2 to 1.61 mm and a slurry liquid supplied to the aluminum plate surface.
Although a well-known thing can be used as an abrasive | polishing agent, quartz sand, quartz, aluminum hydroxide, or a mixture thereof is preferable. Details are described in JP-A-6-135175 and JP-B-50-40047.
The specific gravity of the slurry liquid is preferably 1.05 to 1.3. Of course, a method of spraying a slurry liquid, a method of using a wire brush, a method of transferring the surface shape of an uneven rolling roll to an aluminum plate, or the like may be used. Other methods are described in JP-A-55-074898, JP-A-61-162351, JP-A-63-104889, and the like.

The concentration of the alkaline aqueous solution used for the chemical etching treatment in the alkaline aqueous solution is preferably 1 to 30% by mass, and the alloy component contained in the aluminum alloy as well as aluminum may contain 0 to 10% by mass.
As the alkaline aqueous solution, an aqueous solution mainly composed of caustic soda is particularly preferable. The liquid temperature is preferably from room temperature to 95 ° C., and the treatment is preferably performed for 1 to 120 seconds.
After the etching process is completed, it is preferable to perform liquid draining with a nip roller and water washing with a spray so as not to bring the processing liquid into the next process.

Dissolution amount of the aluminum plate in the first alkali etching treatment is preferably from 0.5 to 30 g / m ^2, more preferably from ^{1.0~20g / m 2, 3.0~15g / m} 2 More preferably.
In the second alkali etching treatment, dissolved amount of the aluminum plate is preferably a 0.001~30g / m ^2, more preferably from 0.1-4 g / m ^2, 0.2 to 1.5 g More preferably, it is / m ² .
In the third alkali etching treatment, dissolved amount of the aluminum plate is preferably a 0.001~30g / m ^2, more preferably from 0.01~0.8g / m ^2, 0.02~0 More preferably, it is 3 g / m ² .

In chemical etching treatment (first to third desmutting treatment) in an acidic aqueous solution, phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid containing two or more acids thereof is preferably used.
The concentration of the acidic aqueous solution is preferably 0.5 to 60% by mass.
Further, in the acidic aqueous solution, 0 to 5% by mass of the alloy component contained in the aluminum alloy as well as aluminum may be dissolved.
The liquid temperature is from room temperature to 95 ° C., and the treatment time is preferably 1 to 120 seconds. After the desmut treatment is completed, it is preferable to carry out liquid removal by a nip roller and water washing by spraying in order not to bring the treatment liquid into the next process.

The aqueous solution used for the electrochemical surface roughening treatment will be described.
The aqueous solution mainly composed of nitric acid used in the first electrochemical surface roughening treatment can be one used for an electrochemical surface roughening treatment using a normal direct current or alternating current, and an aqueous nitric acid solution of 1 to 100 g / liter. 1 to 1 g / liter to saturation of nitric acid ions such as aluminum nitrate, sodium nitrate and ammonium nitrate; hydrochloric acid ions such as aluminum chloride, sodium chloride and ammonium chloride; be able to.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and a silica, may melt | dissolve in the aqueous solution which has nitric acid as a main component.
Specifically, it is preferable to use a solution in which aluminum chloride and aluminum nitrate are added so that aluminum ions are 3 to 50 g / liter in a 0.5 to 2 mass% nitric acid aqueous solution.
The temperature is preferably 10 to 90 ° C, more preferably 40 to 80 ° C.

On the other hand, the aqueous solution mainly composed of hydrochloric acid used in the second electrochemical surface roughening treatment can be one used for an electrochemical surface roughening treatment using a normal direct current or alternating current, and is 1 to 100 g / liter. Add one or more of hydrochloric acid or nitric acid compound containing nitric acid ions such as aluminum nitrate, sodium nitrate, ammonium nitrate; hydrochloric acid ions such as aluminum chloride, sodium chloride, ammonium chloride; Can be used.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and a silica, may melt | dissolve in the aqueous solution which has hydrochloric acid as a main component.
Specifically, it is preferable to use a solution in which aluminum chloride and aluminum nitrate are added so that aluminum ions are 3 to 50 g / liter in a 0.5 to 2 mass% nitric acid aqueous solution.
Moreover, 10-60 degreeC is preferable and 20-50 degreeC is more preferable. Hypochlorous acid may be added.

On the other hand, the aqueous solution mainly composed of hydrochloric acid used in the electrochemical surface roughening treatment in an aqueous hydrochloric acid solution can be one used for the electrochemical surface roughening treatment using ordinary direct current or alternating current, and 1 to 100 g. 0 to 30 g / liter of sulfuric acid can be added to a / liter hydrochloric acid aqueous solution. In addition, one or more of hydrochloric acid or nitric acid compound having nitrate ions such as aluminum nitrate, sodium nitrate, ammonium nitrate; hydrochloric acid ions such as aluminum chloride, sodium chloride, ammonium chloride; Can be used.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, and a silica, may melt | dissolve in the aqueous solution which has hydrochloric acid as a main component.
Specifically, it is preferable to use a solution obtained by adding aluminum chloride, aluminum nitrate, or the like in an aqueous solution of 0.5 to 2% by mass of nitric acid so that aluminum ions are 3 to 50 g / liter.
Moreover, 10-60 degreeC is preferable and 20-50 degreeC is more preferable. Hypochlorous acid may be added.

  A sine wave, a rectangular wave, a trapezoidal wave, a triangular wave, or the like can be used as the AC power supply waveform for the electrochemical roughening treatment. The frequency is preferably 0.1 to 250 Hz.

FIG. 1 is a graph showing an example of an alternating waveform current waveform diagram used for electrochemical roughening treatment in the method for producing a lithographic printing plate support of the present invention.
In FIG. 1, ta is the anode reaction time, tc is the cathode reaction time, tp is the time until the current reaches the peak from 0, Ia is the peak current on the anode cycle side, and Ic is the peak current on the cathode cycle side It is. In the trapezoidal wave, the time tp until the current reaches a peak from 0 is preferably 1 to 10 msec. Due to the influence of the impedance of the power supply circuit, if tp is less than 1, a large power supply voltage is required at the rise of the current waveform, and the equipment cost of the power supply increases. When it is longer than 10 msec, it is easily affected by a trace component in the electrolytic solution, and uniform surface roughening is difficult to be performed. The condition of one cycle of alternating current used for electrochemical surface roughening is that the ratio tc / ta of the anode reaction time ta to the cathode reaction time tc of the aluminum plate is 1 to 20, the quantity of electricity Qc when the aluminum plate is anode and the anode It is preferable that the ratio Qc / Qa of the amount of electricity Qa is 0.3 to 20 and the anode reaction time ta is 5 to 1000 msec. tc / ta is more preferably 2.5 to 15. Qc / Qa is more preferably 2.5 to 15. The current density is preferably a trapezoidal wave peak value of 10 to 200 A / dm ² for both the anode cycle side Ia and the cathode cycle side Ic of the current. Ic / Ia is preferably in the range of 0.3-20. The total amount of electricity furnished to anode reaction of the aluminum plate at the time the electrochemical graining is finished preferably 25~1000C / dm ^2.

  In the present invention, as an electrolytic cell used for electrochemical surface roughening using alternating current, known electrolytic cells such as vertical, flat and radial types can be used. A radial electrolytic cell as described in 195300 is particularly preferred. The electrolyte passing through the electrolytic cell may be parallel to the progress of the aluminum web or may be a counter. One or more AC power sources can be connected to one electrolytic cell. Two or more electrolytic cells can be used.

The apparatus shown in FIG. 2 can be used for electrochemical surface roughening using alternating current.
FIG. 2 is a side view showing an example of a radial cell in an electrochemical surface roughening treatment using alternating current in the method for producing a lithographic printing plate support of the present invention.
In FIG. 2, 50 is a main electrolytic cell, 51 is an AC power source, 52 is a radial drum roller, 53a and 53b are main electrodes, 54 is an electrolyte supply port, 55 is an electrolyte, 56 is an auxiliary anode, and 60 is an auxiliary anode cell. , W is an aluminum plate. When two or more electrolytic cells are used, the electrolysis conditions may be the same or different.
The aluminum plate W is wound around a radial drum roller 52 disposed so as to be immersed in the main electrolytic cell 50, and is subjected to electrolytic treatment by main electrodes 53a and 53b connected to the AC power source 51 in the course of conveyance. The electrolytic solution 55 is supplied from the electrolytic solution supply port 54 to the electrolytic solution passage 57 between the radial drum roller 52 and the main poles 53a and 53b through the slit 56. The aluminum plate W treated in the main electrolytic cell 50 is then subjected to electrolytic treatment in the auxiliary anode cell 60. An auxiliary anode 58 is disposed opposite to the aluminum plate W in the auxiliary anode tank 60, and the electrolytic solution 55 is supplied so as to flow in the space between the auxiliary anode 58 and the aluminum plate W.

On the other hand, in the electrochemical surface roughening process (first and second electrochemical surface roughening processes), a direct current is applied between the aluminum plate and the electrode facing the aluminum plate to electrochemically roughen the surface. There may be.
As the electrolytic solution, one used for electrochemical surface roughening treatment using a known direct current or alternating current can be used. The temperature is preferably 10 to 80 ° C. As a processing apparatus used for electrochemical surface roughening using direct current, one using a known direct current can be used. However, as described in JP-A-1-141094, a pair of anodes and cathodes are used. It is preferable to use an alternating arrangement. Examples of known devices are described in Japanese Patent Application No. 5-68204, Japanese Patent Application No. 6-205657, Japanese Patent Application No. 6-21050, Japanese Patent Application Laid-Open No. 61-19115, Japanese Patent Application No. 57-44760, and the like. Further, an electrochemical surface roughening treatment may be performed by applying a direct current between the conductor roll contacting the aluminum plate and the cathode facing the conductor roll, and using the aluminum plate as the anode. After the electrolytic treatment is completed, it is preferable to perform liquid draining with a nip roller and water washing with a spray so as not to bring the treatment liquid into the next step. The direct current used for electrochemical roughening is preferably a direct current having a ripple rate of 20% or less. The current density is preferably 10 to 200 A / dm ² , and the amount of electricity when the aluminum plate is an anode is preferably 25 to 1000 C / dm ² . The anode can be selected from known oxygen-generating electrodes such as ferrite, iridium oxide, platinum, or platinum plated with a valve metal such as titanium, niobium or zirconium. The cathode can be selected from carbon, platinum, titanium, niobium, zirconium, stainless steel and electrodes used for fuel cell cathodes.

[Lithographic printing plate precursor]
The lithographic printing plate support of the present invention can be used as the lithographic printing plate precursor of the present invention by providing an image recording layer.

<Image recording layer>
The image recording layer that can be used in the lithographic printing plate precursor according to the invention can be removed by printing ink and / or fountain solution. Specifically, the infrared ray absorbent, the polymerization initiator, and the polymerizable property are used. The image recording layer preferably has a compound and can be recorded by infrared irradiation.
In the lithographic printing plate precursor of the present invention, the exposed portion of the image recording layer is cured by infrared irradiation to form a hydrophobic (lipophilic) region, and the unexposed portion is dampened with water, ink or ink at the start of printing. It is quickly removed from the support by an emulsion of fountain solution and ink.
Hereinafter, each component of the image recording layer will be described.

(Infrared absorber)
When forming an image of the lithographic printing plate precursor according to the present invention using a laser emitting infrared rays of 760 to 1200 nm as a light source, an infrared absorber is usually used.
The infrared absorber has a function of converting the absorbed infrared ray into heat and a function of being excited by the infrared ray and transferring electrons / energy to a polymerization initiator (radical generator) described later.
The infrared absorbent that can be used in the present invention is a dye or pigment having an absorption maximum at a wavelength of 760 to 1200 nm.

As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used.
Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.
Preferred dyes include, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, and the like; JP-A-58-173696; The methine dyes described in JP-A-58-181690 and JP-A-58-194595, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, Naphthoquinone dyes described in JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, and the like; squarylium dyes described in JP-A-58-112792, etc. And cyanine dyes described in British Patent No. 434,875.

  Moreover, as another example preferable as a dye, the near-infrared absorptive dye described as the formula (I) and (II) in US Patent 4,756,993 can be mentioned.

  On the other hand, as another preferred example of the dye, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 can also be suitably used. Specifically, US Pat. Substituted arylbenzo (thio) pyrylium salts described in U.S. Pat. No. 4,881,924; trimes described in JP-A-57-142645 (US Pat. No. 4,327,169). Chinthiapyrylium salt: JP-A Nos. 58-181051, 58-220143, 59-41363, 59-84248, 59-84249, 59-146063, and 59-146061 Pyryllium compounds described in Japanese Patent Publication; cyanine dyes described in JP-A-59-216146; described in US Pat. No. 4,283,475 It is to have pentamethine thio pyrylium salt; Kokoku 5-13514 Patent, pyrylium compounds described in JP Nos. 5-19702; and the like can also be suitably used.

  Further, as another example preferable as a dye, an infrared absorbing dye can also be suitably used. Specific examples thereof include a specific indolenine cyanine dye described in JP-A-2002-278057 as exemplified below. Is mentioned.

  Among the dyes exemplified above, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferable, and one particularly preferable example is a cyanine dye represented by the following general formula (i).

In formula (i), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below.
Here, X ² represents an oxygen atom, a nitrogen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. Here, the hetero atom means a nitrogen atom, a sulfur atom, an oxygen atom, a halogen atom, or a selenium atom. Further, X a ^_- is, Z _a to be described later ^_- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred substituents include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, an alkoxy group having 12 or less carbon atoms, a hydrocarbon group having 12 or less carbon atoms, and 12 carbon atoms. Most preferred are not more than alkoxy groups.
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. Preferable substituents include an alkoxy group having 12 or less carbon atoms, a carboxyl group, and a sulfo group, and an alkoxy group having 12 or less carbon atoms is most preferable.
R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred.
Z _a ^- represents a counter anion. However, when the cyanine dye represented by formula (i) has an anionic substituent in the structure thereof, Z _a is does not require charge neutralization ^- is not necessary. Preferred Z _a ⁻ is halide ion (eg, Cl ⁻ , Br ⁻ etc.), perchlorate ion (ClO ₄ ⁻ ), tetrafluoroborate ion (BF ₄ ⁻ ), in view of storage stability of the recording layer coating solution. Hexafluorophosphate ions (PF ₆ ⁻ ) and sulfonate ions, particularly preferably perchlorate ions, tetrafluoroborate ions, hexafluorophosphate ions, and aryl sulfonate ions.

Specific examples of cyanine dyes represented by formula (i) that can be suitably used in the present invention include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. Can do.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057 described above.

  On the other hand, as pigments, for example, commercially available pigment and color index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986) ), "Printing ink technology" CMC publication, published in 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.
Of these pigments, carbon black is preferred.

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

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

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

These infrared absorbers may be added to the same layer as the other components, or may be added to another layer provided, but when a negative lithographic printing plate precursor is produced, image recording The layer is added so that the absorbance at the maximum absorption wavelength in the wavelength range of 760 nm to 1200 nm is in the range of 0.3 to 1.2 by the reflection measurement method. Preferably, it is the range of 0.4-1.1. Within this range, a uniform polymerization reaction proceeds in the depth direction of the image recording layer, and good film strength of the image area and adhesion to the lithographic printing plate support can be obtained.
The absorbance of the image recording layer can be adjusted by the amount of infrared absorber added to the image recording layer and the thickness of the image recording layer. Absorbance can be measured by a conventional method. As a measuring method, for example, on a reflective support such as aluminum, an image recording layer having a thickness appropriately determined in a range in which the coating amount after drying is necessary as a lithographic printing plate is formed, and the reflection density is set to the optical density. And a method of measuring with a spectrophotometer by a reflection method using an integrating sphere.

(Polymerization initiator)
The polymerization initiator is a compound that generates radicals by energy of light, heat, or both, and initiates and accelerates polymerization of a compound having a polymerizable unsaturated group. In the present invention, it generates radicals by heat. It is preferable to use a compound (thermal radical generator).
As the polymerization initiator, a known thermal polymerization initiator, a compound having a bond with a small bond dissociation energy, a photopolymerization initiator, or the like can be used.

  Specific examples of compounds that generate radicals include, for example, organic halides, carbonyl compounds, organic peroxides, azo polymerization initiators, azide compounds, metallocene compounds, hexaarylbiimidazole compounds, and organic borate compounds. , Disulfone compounds, oxime ester compounds, onium salt compounds, and the like.

  Specific examples of the organic halide include Wakabayashi et al., “Bull Chem. SocJapan” 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Examined Patent Publication No. 46-4605, 48-36281, JP-A 55-32070, JP-A 60-239736, JP-A 61-169835, JP-A 61-169837, JP-A 62-58241, JP-A 62- No. 212401, JP-A 63-70243, JP-A 63-298339, P. Examples thereof include compounds described in Hutt “Journal of Heterocyclic Chemistry” 1 (No 3), (1970) ”, and particularly preferred are oxazole compounds substituted with a trihalomethyl group and S-triazine compounds.

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

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

  As the azo polymerization initiator, for example, azo compounds described in JP-A-8-108621 can be used.

  Specific examples of the organic peroxide include trimethylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1- Bis (tert-butylperoxy) cyclohexane, 2,2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2 , 5-Dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tert-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butyl) Peroxy) Sun, 2,5-oxanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxy Ethyl peroxydicarbonate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyneodeca Noate, tert-butyl peroxyoctanoate, tert-butyl peroxylaurate, tersyl carbonate, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3 3 ', 4,4'-tetra- (t-hexylperoxycarbonyl) benzophenone, 3,3', 4,4'-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxy) Oxydihydrogen diphthalate), carbonyldi (t-hexylperoxydihydrogen diphthalate), and the like.

  Examples of the metallocene compound include, for example, JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. Various titanocene compounds described in JP-A-5-83588, specifically, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,6 -Difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-tri Fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2, , 4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis- 2,4,6-trifluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl- Ti-bis-2,3,4,5,6-pentafluorophen-1-yl; iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109; It is done.

  Examples of the hexaarylbiimidazole compound include JP-B-6-29285, U.S. Pat. Nos. 3,479,185, 4,311,783, and 4,622,286. Various compounds described in the literature, specifically 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o -Bromophenyl)) 4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2 , 2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (m-methoxyphenyl) biidazole, 2,2'-bis (o, o'-dichlorophenyl) -4,4', 5,5'-tetra Phenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4', Examples include 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, and the like.

  Specific examples of the organic borate compound include, for example, JP-A-62-143044, JP-A-62-1050242, JP-A-9-188865, JP-A-9-188686, and JP-A-9-9-1. 188710, JP-A-2000-131837, JP-A-2002-107916, JP-A-2766769, JP-A-2002-116539, and Kunz, Martin “Rad Tech'98. Proceeding April 19- 22, 1998, Chicago ”, etc .; organic boron sulfonium complexes or organic compounds described in JP-A-6-157623, JP-A-6-175564, JP-A-6-175561 Boron oxosulfonium complex; JP-A-6-175554 The organic boron iodonium complex described in JP-A-6-175553; the organic boron phosphonium complex described in JP-A-9-188710; JP-A-6-348011, JP-A-7-128785 And organic boron transition metal coordination complexes described in JP-A-7-140589, JP-A-7-306527, JP-A-7-292014, and the like.

  As said disulfone compound, the compound described in Unexamined-Japanese-Patent No. 61-166544, Unexamined-Japanese-Patent No. 2003-328465 etc. is mentioned, for example.

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

  Examples of the onium salt compound include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980); ammonium salts described in US Pat. No. 4,069,055, JP-A-4-365049, etc .; US patents Phosphonium salts described in the specifications of US Pat. Nos. 4,069,055 and 4,069,056; European Patent Nos. 104 and 143, US Pat. Nos. 339,049 and 410,201 Iodonium salts described in each specification, JP-A-2-150848 and JP-A-2-296514; European Patents 370,693, 390,214, 233,567, and 297 No. 4,443, No. 297,442, US Pat. Nos. 4,933,377, 161,811, 410,201, 339,049, , 760,013, 4,734,444, 2,833,827, German Patents 2,904,626, 3,604,580, 3,604,581 The sulfonium salts described in the specification; V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979); C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curium ASIA, p478 Tokyo, Oct (1988); onium salts such as;

Among these onium salts, the above oxime ester compounds, diazonium salts, iodonium salts, and sulfonium salts are preferable in terms of reactivity and stability.
In the present invention, these onium salts function not as acid generators but as ionic radical polymerization initiators.
Further, as these onium salts, onium salts represented by the following general formulas (RI-I) to (RI-III) are preferably used.

In the formula (RI-I), Ar ¹¹ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents. Preferred substituents include alkyl groups having 1 to 12 carbon atoms, alkenyl groups having 1 to 12 carbon atoms, alkynyl groups having 1 to 12 carbon atoms, aryl groups having 1 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms. An aryloxy group having 1 to 12 carbon atoms, a halogen atom, an alkylamino group having 1 to 12 carbon atoms, a dialkylamino group having 1 to 12 carbon atoms, an alkylamide group or arylamide group having 1 to 12 carbon atoms, a carbonyl group, Examples thereof include a carboxyl group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms.
On the other hand, Z ^11- represents a monovalent anion (anion), and specific examples thereof include halide ions (for example, Cl ⁻ , Br ^−, etc.), perchlorate ions (ClO ₄ ⁻ ), hexafluorophos. Fate ions (PF ₆ ⁻ ), tetrafluoroborate ions (BF ₄ ⁻ ), sulfonate ions, sulfinate ions, thiosulfonate ions, sulfate ions and the like can be mentioned. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, and sulfinate ion are preferable from the viewpoint of stability.

In the formula (RI-II), Ar ²¹ and Ar ²² each independently represent an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents. Preferred substituents include alkyl groups having 1 to 12 carbon atoms, alkenyl groups having 1 to 12 carbon atoms, alkynyl groups having 1 to 12 carbon atoms, aryl groups having 1 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms. An aryloxy group having 1 to 12 carbon atoms, a halogen atom, an alkylamino group having 1 to 12 carbon atoms, a dialkylamino group having 1 to 12 carbon atoms, an alkylamide group or arylamide group having 1 to 12 carbon atoms, a carbonyl group, Examples thereof include a carboxyl group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms.
On the other hand, Z ²¹⁻ represents a monovalent anion (anion), and specific examples thereof include halide ions (eg, Cl ⁻ , Br ⁻ etc.), perchlorate ions (ClO ₄ ⁻ ), hexafluorophos. Fate ions (PF ₆ ⁻ ), tetrafluoroborate ions (BF ₄ ⁻ ), sulfonate ions, sulfinate ions, thiosulfonate ions, sulfate ions and the like can be mentioned. Of these, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, and carboxylate ions are preferable from the viewpoints of stability and reactivity.

In formula (RI-III), R ³¹ , R ³² and R ³³ each independently represents an aryl group having 20 or less carbon atoms, an alkyl group, an alkenyl group or an alkynyl group which may have 1 to 6 substituents. In view of reactivity and stability, an aryl group is desirable. Preferred substituents include alkyl groups having 1 to 12 carbon atoms, alkenyl groups having 1 to 12 carbon atoms, alkynyl groups having 1 to 12 carbon atoms, aryl groups having 1 to 12 carbon atoms, and alkoxy groups having 1 to 12 carbon atoms. An aryloxy group having 1 to 12 carbon atoms, a halogen atom, an alkylamino group having 1 to 12 carbon atoms, a dialkylamino group having 1 to 12 carbon atoms, an alkylamide group or arylamide group having 1 to 12 carbon atoms, a carbonyl group, Examples thereof include a carboxyl group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms.
On the other hand, Z ^31- represents a monovalent anion (anion), and specific examples thereof include halide ions (eg, Cl ⁻ , Br ⁻ etc.), perchlorate ions (ClO ₄ ⁻ ), hexafluorophos. Fate ions (PF ₆ ⁻ ), tetrafluoroborate ions (BF ₄ ⁻ ), sulfonate ions, sulfinate ions, thiosulfonate ions, sulfate ions and the like can be mentioned. Of these, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, and carboxylate ions are preferable from the viewpoints of stability and reactivity. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.
Although the example of the onium salt used suitably as a polymerization initiator below is given, this invention is not these restrictions.

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

(Polymerizable compound)
The polymerizable compound is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more.
In the present invention, those compounds widely known in the technical field of the present invention can be used without any particular limitation. In addition, such compounds have chemical forms such as monomers, prepolymers, that is, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof.
Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters thereof, amides, and the like. An ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound are preferably used.
In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and a monofunctional or polyfunctional compound. A dehydration condensation reaction product with a functional carboxylic acid is also preferably used.
Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or Also suitable are substitution reaction products of unsaturated carboxylic acid esters or amides having a leaving substituent such as a tosyloxy group with monofunctional or polyfunctional alcohols, amines or thiols.
As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of an ester monomer of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include, for example, 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 Acrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer, isocyanur Examples include acid EO-modified triacrylate.

  Specific examples of the methacrylic acid ester 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-hydroxypropoxy) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane, and the like.

Specific examples of the itaconic acid ester include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, and tetramethylene glycol diitaconate. Nate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.
Specific examples of the crotonic acid ester include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Specific examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.
Specific 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-51-47334 and JP-A-57-196231; JP-A-59-5240, JP-A-59- Those having an aromatic skeleton described in each publication of JP 5241 and JP-A-2-226149; those containing an amino group described in JP-A-1-165613; etc. are also preferably used. . Furthermore, the ester monomers described above can also be used as a mixture.

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

  Also suitable are urethane-based addition polymerizable compounds produced using an addition reaction of isocyanate and hydroxyl groups. Specific examples thereof include two or more per 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 general formula (A) to a polyisocyanate compound having an isocyanate group of Can be mentioned.

^{_{CH 2 = C (R 4)}} COOCH 2 CH (R 5) OH (A)
(However, R ⁴ and R ⁵ represent H or CH _3. )

Further, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765; JP-B-58-49860, JP-B-56-17654, JP-B Preferable examples include urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418.
Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the situation, a photopolymerizable composition having an extremely excellent photosensitive speed can be obtained.

Other examples include polyester acrylates described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, etc .; reaction of epoxy resin with acrylic acid or methacrylic acid And polyfunctional acrylates and methacrylates such as epoxy acrylates;
Specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, and JP-B-1-40336; vinylphosphones described in JP-A-2-25493 An acid compound; etc. can also be mentioned.
In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used.
Furthermore, the Japan Adhesion Association magazine vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

About these addition polymerizable compounds, the details of usage, such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image area, that is, the cured film, those having three or more functionalities are preferable, and furthermore, different functional numbers and different polymerizable groups (for example, acrylic acid ester, methacrylic acid ester, styrene compound, vinyl ether type A method of adjusting both sensitivity and strength by using a compound) is also effective.
Further, the selection and use method of the addition polymerization compound is also an important factor for the compatibility and dispersibility with other components (for example, binder polymer, initiator, colorant, etc.) in the image recording layer. In some cases, the compatibility can be improved by using a low-purity compound or by using two or more kinds in combination.
The addition polymerizable compound is preferably used in the range of 5 to 80% by mass, more preferably 25 to 75% by mass, with respect to the non-volatile component in the image recording layer. These may be used alone or in combination of two or more. In addition, the use method of the addition polymerizable compound can be arbitrarily selected from the viewpoint of polymerization inhibition with respect to oxygen, resolution, fogging, refractive index change, surface adhesiveness, etc. Depending on the case, a layer configuration and coating method such as undercoating and overcoating can be performed.

(Polymer fine particles with polymerizable reactive groups)
In the present invention, the image recording layer preferably contains fine polymer particles having a polymerizable reactive group, in addition to the above-described infrared absorber, polymerization initiator, and polymerizable compound.
Examples of the polymer fine particles having a polymerizable reactive group include those obtained by introducing a monomer having an acryloyl group, a methacryloyl group, a vinyl group or an allyl group into a polymer chain. The introduction of these functional groups into the polymer fine particles may be performed at the time of polymerization, or may be performed using a polymer reaction after the polymerization.

  When introduced at the time of polymerization, it is preferable to subject these monomers having a polymerizable reactive group to a polycondensation reaction such as emulsion polymerization, suspension polymerization, or urethanization. If necessary, a monomer having no polymerizable reactive group may be added as a copolymerization component.

  Specific examples of the monomer having such a functional group include, for example, allyl methacrylate, allyl acrylate, vinyl methacrylate, vinyl acrylate, glycidyl methacrylate, glycidyl acrylate, 2-isocyanate ethyl methacrylate, 2-isocyanate ethyl acrylate, 2- Examples include aminoethyl methacrylate, 2-aminoethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylic acid, methacrylic acid, maleic anhydride, bifunctional acrylate, bifunctional methacrylate, and the like. Not.

  Examples of the polymer reaction used when the polymerization-reactive functional group is introduced after the polymerization include a polymer reaction described in WO 96-034316.

The polymer fine particles having a polymerizable reactive group may be combined with each other by heat.
Further, it is particularly preferable that the surface of the polymer fine particles is hydrophilic and is dispersed in water. In order to make the surface of the polymer fine particles hydrophilic, a hydrophilic polymer or oligomer such as polyvinyl alcohol or polyethylene glycol, or a hydrophilic low molecular weight compound may be adsorbed on the surface of the polymer fine particles, but the method is limited to these. It is not something.
Further, the average particle size of the polymer fine particles is preferably 0.01 to 10 μm, more preferably 0.05 to 2 μm, and most preferably 0.1 to 1 μm. If the average particle size is too large, the resolution will be poor, and if it is too small, the stability over time will be poor.

  Further, the form of the polymer fine particle having a polymerizable reactive group may be a microcapsule or a microgel encapsulating a compound having a polymerizable reactive group without forming a covalent bond with the compound having a polymerizable reactive group. .

That is, in the present invention, several modes can be used as a method for incorporating the above-described image recording layer constituents into the image recording layer.
One is a molecular dispersion type image recording layer in which the constituent components are dissolved and applied in an appropriate solvent as described in, for example, JP-A-2002-287334.
In another embodiment, as described in, for example, JP-A-2001-277740 and JP-A-2001-277742, all or part of the constituent components are encapsulated in microcapsules and contained in the image recording layer. It is a capsule type image recording layer. Further, in the microcapsule type image recording layer, the constituent component can be contained outside the microcapsule. Here, it is preferable that the microcapsule-type image recording layer includes a hydrophobic constituent component in the microcapsule and a hydrophilic constituent component outside the microcapsule. In order to obtain better on-press developability, the image recording layer is preferably a microcapsule type image recording layer.

  The microcapsule or microgel in the form of polymer fine particles having a polymerizable reactive group used in the present invention contains a compound having a polymerizable reactive group. As the compound having a polymerizable reactive group, the above-described polymerizable compound can be used without limitation.

  A known method can be applied as a method for microencapsulating the constituent components of the image recording layer. For example, as a method for producing microcapsules, a method using coacervation described in US Pat. Nos. 2,800,547 and 2,800,498; each specification of US Pat. No. 3,287,154, Japanese Patent Publication No. 38-19574 No. 42-446, a method based on an interfacial polymerization method; U.S. Pat. Nos. 3,418,250 and 3,660,304; a method based on precipitation of a polymer; U.S. Pat. No. 3,796,669. US Pat. No. 3,914,511, US Pat. No. 4,087,376, US Pat. No. 4,089,802; US Pat. No. 3,914,511; US Pat. No. 3,914,511; US Pat. The urea-formaldehyde system described in each specification of Is a method using a urea formaldehyde-resorcinol-based wall forming material; a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose described in US Pat. No. 4,025,445; In situ method by monomer polymerization described in each publication of No. 9079; spray drying method described in British Patent No. 930422 and US Pat. No. 3111407; British Patent Nos. 952807 and 967074 However, it is not limited to the electrolytic dispersion cooling method described in each specification.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Further, the compound having a polymerizable reactive group may be introduced into the microcapsule wall.

The average particle diameter of the microcapsules is preferably 0.01 to 10 μm, more preferably 0.05 to 2 μm, and particularly preferably 0.1 to 1 μm. If the average particle size is too large, the resolution will be poor, and if it is too small, the stability over time will be poor.
Such microcapsules may be combined with each other by heat or may not be combined.

(Binder polymer)
In the present invention, a binder polymer can be used for the image recording layer in order to improve the film forming property of the image recording layer.
Conventionally known binder polymers can be used without limitation, and polymers having film properties are preferred. Specifically, as such a binder polymer, for example, acrylic resin, polyvinyl acetal resin, polyurethane resin, polyurea resin, polyimide resin, polyamide resin, epoxy resin, methacrylic resin, polystyrene resin, novolac phenolic resin, Polyester resin, synthetic rubber, natural rubber and the like can be mentioned.
The binder polymer may have crosslinkability in order to improve the film strength of the image area. In order to impart crosslinkability to the binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the main chain or side chain of the polymer. The crosslinkable functional group may be introduced by copolymerization.
Examples of the polymer having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-butadiene, poly-1,4-isoprene and the like.
Examples of the polymer having an ethylenically unsaturated bond in the side chain of the molecule include an ester or amide polymer of acrylic acid or methacrylic acid, and an ester or amide residue (R of —COOR or CONHR) is ethylene. Examples thereof include polymers having a polymerizable unsaturated bond.

The residue having an ethylenically unsaturated bond (the above R), specifically, for _{example, - (CH 2) n CR} 1 = CR 2 R 3, - (CH 2 O) n CH 2 CR 1 = CR _{^{2 R 3, - (CH 2}} CH 2 O) n CH 2 CR 1 = CR 2 R 3, - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, - (CH 2) _n— O—CO—CR ¹ ═CR ² R ³ and (CH ₂ CH ₂ O) ₂ —X (wherein R ^{1 to} R ³ are each a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms) Represents an aryl group, an alkoxy group or an aryloxy group, and R ¹ and R ² or R ³ may combine with each other to form a ring, n represents an integer of 1 to 10. X represents a di Represents a cyclopentadienyl residue.).
The ester residue, specifically, for _{example, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - CH 2 CH 2} O-CH 2 CH = CH 2, _{-CH 2 C (CH 3) =} CH 2, -CH 2 CH = CH-C 6 H 5, -CH 2 CH 2 OCOCH = CH-C 6 H 5, -CH 2 CH 2 -NHCOO-CH 2 CH = CH ₂ and CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
Specific examples of the amide residue include, for example, —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (wherein Y represents a cyclohexene residue), —CH ₂ CH ₂ —OCO—. CH = CH ₂ is mentioned.

  In the case of a binder polymer having crosslinkability, for example, free radicals (polymerization initiation radicals or growth radicals in the polymerization process of a polymerizable compound) are added to the crosslinkable functional group, and a polymerization chain of a polymerizable compound is formed directly between polymers. Through addition polymerization, a cross-link is formed between the polymer molecules and cured. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded to each other so that crosslinking between the polymer molecules occurs. Forms and cures.

  The content of the crosslinkable group in the binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1.0, per 1 g of the binder polymer. -7.0 mmol, most preferably 2.0-5.5 mmol. Within this range, good sensitivity and good storage stability can be obtained.

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

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

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

  The binder polymer preferably has a mass average molecular weight of 5,000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more, preferably 2000 to 250,000. More preferred. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.

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

The content of the binder polymer is 5 to 90% by mass, preferably 5 to 80% by mass, and more preferably 10 to 70% by mass with respect to the total solid content of the image recording layer. Within this range, good image area strength and image formability can be obtained.
Moreover, it is preferable to use a polymeric compound and a binder polymer in the quantity used as mass ratio 0.5 / 1-4/1.

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

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

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

A cationic surfactant is not specifically limited, A conventionally well-known thing can be used. For example, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives and the like can be mentioned.
An amphoteric surfactant is not specifically limited, A conventionally well-known thing can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric esters, imidazolines and the like.

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

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

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass and more preferably 0.01 to 5% by mass with respect to the total solid content of the image recording layer.

(Coloring agent)
In the present invention, various compounds other than these may be added to the image recording layer as necessary. For example, a dye having a large absorption in the visible light region can be used as an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Manufactured by Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI52015), Japanese Patent Laid-Open No. 62-293247 Can be mentioned. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can be suitably used.
These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The addition amount is 0.01 to 10% by mass with respect to the total solid content of the image recording material.

(Bake-out agent)
In the present invention, a compound that changes color by an acid or a radical can be added to the image recording layer to produce a printout image.
As such a compound, for example, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

  Specifically, brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinalgin red, rose bengal, metanil yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafuchsin, Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Kogyo Co., Ltd.], Oil Pink # 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Chemistry] Made by Co., Ltd.], Oil Red OG [produced by Orient Chemical Co., Ltd.], Oil Red RR [produced by Orient Chemical Co., Ltd.], Oil Green # 502 [produced by Orient Chemical Co., Ltd.], Spiron Red BEH Special [Hodogaya Chemical Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p-diethylamino Phenyliminonaphthoquinone, 2-carboxystearylamino-4-pN, N-bis (hydroxyethyl) amino-phenyliminonaphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1 -Β-naphthyl-4-p- Dyes and p and ethyl aminophenyl imino-5-pyrazolone, p ', p "- hexamethyl triamnotriphenylmethane (leuco crystal violet), Pergascript Blue SRB (manufactured by Ciba-Geigy) a leuco dye or the like, and the like.

  In addition to the above, a leuco dye known as a material for thermal paper or pressure-sensitive paper is also suitable. Specifically, crystal violet lactone, malachite green lactone, benzoyl leucomethylene blue, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) amino-fluorane, 2-anilino -3-methyl-6- (N-ethyl-p-toluidino) fluorane, 3,6-dimethoxyfluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) ) -Fluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane, 3 -(N, N-diethylamino) -6-methyl-7-xylidinofluorane, 3- (N, N-diethylamino) -6-methyl-7-chloroph Oran, 3- (N, N-diethylamino) -6-methoxy-7-aminofluorane, 3- (N, N-diethylamino) -7- (4-chloroanilino) fluorane, 3- (N, N-diethylamino) -7-chlorofluorane, 3- (N, N-diethylamino) -7-benzylaminofluorane, 3- (N, N-diethylamino) -7,8-benzofluorane, 3- (N, N-dibutyl) Amino) -6-methyl-7-anilinofluorane, 3- (N, N-dibutylamino) -6-methyl-7-xylidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-n-butyl-2) − Tilindole-3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2) -Methylindol-3-yl) -4-zaphthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide and the like.

  A suitable addition amount of the dye that changes color by an acid or a radical is 0.01 to 10% by mass with respect to the solid content of the image recording layer.

(Polymerization inhibitor)
In the present invention, a small amount of a thermal polymerization inhibitor is added to the image recording layer as a polymerization inhibitor in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during the production or storage of the image recording layer. Is preferred.
Specific examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4′-thiobis (3-methyl). -6-t-butylphenol), 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt and the like are preferable. The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the image recording layer.

(Higher fatty acid derivatives, etc.)
In the present invention, a higher fatty acid derivative such as behenic acid or behenic acid amide or the like is added to the image recording layer in order to prevent polymerization inhibition due to oxygen, and the image recording layer is dried during the coating process. It may be unevenly distributed on the surface. The amount of the higher fatty acid derivative added is preferably about 0.1 to about 10% by mass with respect to the total solid content of the image recording layer.

(Plasticizer)
In the present invention, the image recording layer may contain a plasticizer in order to improve on-press developability.
Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; Glycol esters such as glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate; polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate in.
The plasticizer content is preferably about 30% by mass or less based on the total solid content of the image recording layer.

(Inorganic fine particles)
In the present invention, the image recording layer may contain inorganic fine particles in order to improve the cured film strength of the image area and the on-press developability of the non-image area.
As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate or a mixture thereof can be preferably mentioned. Even if they are not photothermally convertible, they can be used for strengthening the film, enhancing interfacial adhesion by surface roughening, and the like.
The inorganic fine particles preferably have an average particle size of 5 nm to 10 μm, and more preferably 0.5 μm to 3 μm. Within the above range, it is possible to form a non-image portion having excellent hydrophilicity, which is stably dispersed in the image recording layer, sufficiently retains the film strength of the image recording layer, and hardly causes stains during printing.
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 40% by mass or less, and more preferably 30% by mass or less, based on the total solid content of the image recording layer.

(Low molecular hydrophilic compound)
In the present invention, the image recording layer may contain a hydrophilic low molecular weight compound in order to improve the on-press developability.
Examples of the hydrophilic low molecular weight compound include, as water-soluble organic compounds, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and ether or ester derivatives thereof; glycerin, penta Polyhydroxys such as erythritol; Organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof; Organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof; Organic phosphonic acids such as phenylphosphonic acid and their salts Salt; organic carboxylic acids such as tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid, amino acids and salts thereof; and the like.

<Formation of image recording layer>
The image recording layer is coated by preparing a coating solution by dispersing or dissolving the necessary components in a solvent. Here, as a solvent to be used, 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, Examples include dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water and the like. Yes, but not limited to this.
These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The image recording layer can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeating a plurality of coatings and dryings.

Further, the coating amount (solid content) of the image recording layer on the lithographic printing plate support obtained after coating and drying varies depending on the use, but is generally preferably 0.3 to 3.0 g / m ² . Within this range, good sensitivity and good film characteristics of the image recording layer can be obtained.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

<Undercoat layer>
In the lithographic printing plate precursor according to the invention, it is desirable to provide an undercoat layer between the image recording layer and the lithographic printing plate support.

(Polymer having substrate adsorptive group, polymerizable group and hydrophilic group)
In the present invention, the undercoat layer preferably contains a polymer having a substrate adsorptive group, a polymerizable group, and a hydrophilic group.
As the polymer having a substrate adsorptive group, a polymerizable group and a hydrophilic group, a monomer having an adsorptive group, a monomer having a hydrophilic group, and a monomer having a polymerizable reactive group (crosslinkable group) were copolymerized. Mention may be made of polymer resins for undercoating.

One of the essential components of the polymer resin is an adsorptive group to the substrate (hydrophilic support surface). The presence or absence of adsorptivity on the surface of the hydrophilic support can be determined by the following method, for example.
A coating night is prepared by dissolving the test compound in a readily soluble solvent, and the coating night is coated and dried on the support so that the coating amount after drying is 30 mg / m ² . Next, the support coated with the test compound is sufficiently washed with a readily soluble solvent, and then the residual amount of the test compound that has not been removed by washing is measured to calculate the adsorbed amount of the support. Here, the measurement of the remaining amount may be performed by directly quantifying the amount of the remaining compound or by quantifying the amount of the test compound dissolved in the cleaning liquid. The compound can be quantified by, for example, fluorescent X-ray measurement, reflection spectral absorbance measurement, liquid chromatography measurement and the like. The compound having support adsorptivity is a compound that remains at 1 mg / m ² or more even after the above-described washing treatment.

The adsorptive group on the surface of the hydrophilic support is a substance (for example, metal, metal oxide) or a functional group (for example, hydroxyl group) existing on the surface of the hydrophilic support and a chemical bond (for example, ionic bond, hydrogen). Bond, coordination bond, bond by intermolecular force). The adsorptive group is preferably an acid group or a cationic group.
Specific examples of the acid group and the cationic group are the same as the specific examples of the acid group and the cationic group described in the section of the metal adsorbing group of the chelating agent.

  Particularly preferred examples of the monomer having an adsorptive group include compounds represented by the following formula (III) or (IV).

In the above formula, R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms. R ¹ , R ² and R ³ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. More preferred is a hydrogen atom or methyl. R ² and R ³ are particularly preferably a hydrogen atom. Z is a functional group that adsorbs to the surface of the hydrophilic support.

In the formula (III), X is an oxygen atom (—O—) or imino (—NH—). X is more preferably an oxygen atom.
In the formula (III), L is a divalent linking group. L is a divalent aliphatic group (alkylene group, substituted alkylene group, alkenylene group, substituted alkenylene group, alkynylene group, substituted alkynylene group), divalent aromatic group (arylene group, substituted arylene group) or divalent Or an oxygen atom (—O—), a sulfur atom (—S—), an imino (—NH—), a substituted imino (—NR—, R is an aliphatic group, an aromatic group Or a combination with a heterocyclic group) or carbonyl (—CO—).

  The aliphatic group may have a cyclic structure or a branched structure. 1-20 are preferable, as for the carbon atom number of an aliphatic group, 1-15 are more preferable, and 1-10 are the most preferable. The aliphatic group is preferably a saturated aliphatic group rather than an unsaturated aliphatic group. The aliphatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aromatic group, and a heterocyclic group.

6-20 are preferable, as for the carbon atom number of an aromatic group, 6-15 are more preferable, and 6-10 are the most preferable. The aromatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aliphatic group, an aromatic group, and a heterocyclic group.
The heterocyclic group preferably has a 5-membered or 6-membered ring as the heterocycle. The heterocycle may be condensed with another heterocycle, aliphatic ring or aromatic ring. The heterocyclic group may have a substituent. Examples of the substituent include a halogen atom, hydroxyl group, oxo (═O), thio (═S), imino (═NH), substituted imino group (═N—R, R is an aliphatic group, aromatic group or Ring group), aliphatic group, aromatic group and heterocyclic group.

L is preferably a divalent linking group containing a plurality of polyoxyalkylene structures. The polyoxyalkylene structure is more preferably a polyoxyethylene structure. In other words, L preferably contains — (OCH ₂ CH ₂ ) n— (n is an integer of 2 or more).
In the formula (IV), Y is a carbon atom or a nitrogen atom. When Y = nitrogen atom and L is linked to Y to form a quaternary pyridinium group, Z itself is adsorbable and Z is not essential, and Z = H may be used. L represents the same divalent linking group or single bond as in formula (III).

The adsorptive functional group is as described above.
Examples of typical compounds represented by formula (III) or (IV) are shown below.

Examples of the hydrophilic group of the polymer resin for undercoat include, for example, hydroxyl group, carboxyl group, carboxylate group, hydroxyethyl group, polyoxyethyl group, hydroxypropyl group, polyoxypropyl group, amino group, aminoethyl group, amino group Preferred examples include a propyl group, an ammonium group, an amide group, a carboxymethyl group, a sulfonic acid group, and a phosphoric acid group. Of these, sulfonic acid groups exhibiting high hydrophilicity are preferred.
Specific examples of the monomer having a sulfonic acid group include methallyloxybenzene sulfonic acid, allyloxybenzene sulfonic acid, aryl sulfonic acid, vinyl sulfonic acid, p-styrene sulfonic acid, methallyl sulfonic acid, and acrylamide t. -Butylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium salt of (3-acryloyloxypropyl) butylsulfonic acid, amine salt and the like. Of these, 2-acrylamido-2-methylpropanesulfonic acid sodium salt is preferred in view of hydrophilic performance and handling of synthesis.

  The undercoat polymer resin preferably has a polymerizable reactive group. Improvement of adhesion with the image area is obtained by the polymerizable reactive group. In order to make the polymer resin for the undercoat layer crosslinkable, a crosslinkable functional group such as an ethylenically unsaturated bond is introduced into the side chain of the polymer, or the polar substituent of the polymer resin is countercharged. Or a compound having an ethylenically unsaturated bond may be introduced by forming a salt structure.

  Examples of the monomer for introducing an ethylenically unsaturated bond into the side chain of the molecule include an ester or amide monomer of acrylic acid or methacrylic acid, and an ester or amide residue (R of -COOR or CONHR ) May have a monomer having an ethylenically unsaturated bond.

Specific examples of the residue having the ethylenically unsaturated bond (the above R) include, for example, — (CH ₂ ) _n CR ₁ ═CR ₂ R ₃ , — (CH ₂ O) _n CH ₂ CR ₁ ═CR _{2 R 3, - (CH 2} CH 2 O) n CH 2 CR 1 = CR 2 R 3, - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, - (CH 2) _n— O—CO—CR ₁ ═CR ₂ R ₃ and (CH ₂ CH ₂ O) ₂ —X (wherein R _{1 to} R ₃ are each a hydrogen atom, a halogen atom or an alkyl having 1 to 20 carbon atoms) Represents a group, an aryl group, an alkoxy group or an aryloxy group, and R ₁ and R ₂ or R ₃ may combine with each other to form a ring, n represents an integer of 1 to 10. X represents Represents a dicyclopentadienyl residue).
The ester residue, specifically, for _{example, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - CH 2 CH 2} O-CH 2 CH = CH 2, _{-CH 2 C (CH 3) =} CH 2, -CH 2 CH = CH-C 6 H 5, -CH 2 CH 2 OCOCH = CH-C 6 H 5, -CH 2 CH 2 NHCOO-CH 2 CH = CH ₂ and CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
Specific examples of the amide residue include, for example, —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ O—Y (wherein Y represents a cyclohexene residue), —CH ₂ CH ₂ OCO—. CH = CH ₂ is mentioned.

  The content of the polymerizable reactive group in the polymer resin for the undercoat layer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol per 1 g of the polymer resin. More preferably, it is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol. Within this range, both good sensitivity and dirtiness and good storage stability can be obtained.

The polymer resin for the undercoat layer preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1000 or more, preferably 2000 to 25 More preferably, it is 10,000. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The polymer resin for the undercoat layer may be any of a random polymer, a block polymer, a graft polymer, and the like, but is preferably a random polymer.

The undercoat polymer resin may be used alone or in combination of two or more, and the chelating agent may be used alone or in combination of two or more. The undercoat layer coating solution is obtained by dissolving the above-described undercoat polymer resin and a chelating agent in an organic solvent (for example, methanol, ethanol, acetone, methyl ethyl ketone, etc.) and / or water. The undercoat layer coating solution may contain an infrared absorber.
Various known methods can be used as a method of applying the undercoat layer coating solution to the support. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 50 mg / m ^2.

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

  Examples of the material used for the protective layer include water-soluble polymer compounds that are relatively excellent in crystallinity. Specific examples include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid. Among these, when polyvinyl alcohol (PVA) is used as a main component, the best results are obtained for basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol may be partially substituted with an ester, ether or acetal as long as it contains an unsubstituted vinyl alcohol unit for providing the oxygen barrier property and water solubility necessary for the protective layer, and a part of the other You may have a copolymerization component.

  As a polyvinyl alcohol, the thing of the range of the polymerization degree 300-2400 hydrolyzed 71-100 mol% is mentioned suitably, for example. Specifically, for example, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA manufactured by Kuraray Co., Ltd. -HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405 , PVA-420, PVA-613, L-8 and the like.

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

  As a preferred embodiment of the protective layer, there can be mentioned a protective layer containing an inorganic layered compound described in JP-A No. 11-38633. Good oxygen barrier properties can be obtained by combining the inorganic layered compound and the binder. The inorganic layered compound used in the present invention is a particle having a thin planographic shape, for example,

General formula A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂

[However, A is any of K, Na and Ca, and B and C are Fe (II), Fe (III), Mn
, Al, Mg, or V, and D is Si or Al. And mica groups such as natural mica and synthetic mica, talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by the formula 3MgO.4SiO.H ₂ O.

Specific examples of the natural mica include muscovite, soda mica, phlogopite, biotite, and sericite.
Specific examples of synthetic mica include non-swellable mica such as fluorine phlogopite mica ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 Si ₄ O ₁₀ ) F ₂ ; Silic mica NaMg _2.5 (Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , Montmorillonite Na or Li hectorite (Na, Li) _{1 / 8} Swellable mica such as Mg _2/5 Li _1/8 (Si ₄ O ₁₀ ) F ₂ ; Synthetic smectites are also useful.

  In the present invention, among the inorganic layered compounds, fluorine-based swellable mica, which is a synthetic inorganic layered compound, is particularly useful.

  As the shape of the inorganic layered compound used in the present invention, from the viewpoint of diffusion control, the smaller the thickness, the better. The plane size is as long as it does not hinder the smoothness of the coated surface or the transmittance of actinic rays. Larger is better. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

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

  When the inorganic layered compound particles having such a large aspect ratio are contained in the protective layer, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Prevent deterioration.

  The amount contained in the protective layer of the inorganic stratiform compound is preferably 5% by mass to 55% by mass, more preferably 10% by mass to 40% by mass with respect to the total solid content of the protective layer. When the content is 5% by mass or more, an effect on the adhesion resistance is recognized. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass%.

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

  As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the water-soluble polymer compound, and flexibility can be imparted. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the (co) polymer Mass% can be added. The thickness of the protective layer is suitably from 0.1 to 5 μm, particularly preferably from 0.2 to 2 μm.

  In addition, adhesion to the image area, scratch resistance, and the like are extremely important in handling the lithographic printing plate precursor. That is, when a protective layer that is hydrophilic because it contains a water-soluble polymer compound is laminated on the image recording layer when the image recording layer is oleophilic, the protective layer is liable to peel off due to insufficient adhesion, and the peeling occurs. In some parts, defects such as poor film hardening due to inhibition of polymerization by oxygen may occur.

  On the other hand, various proposals have been made to improve the adhesion between the image recording layer and the protective layer. For example, in JP-A-49-70702, a hydrophilic polymer mainly composed of polyvinyl alcohol is mixed with 20 to 60% by mass of an acrylic emulsion, a water-insoluble vinylpyrrolidone-vinyl acetate copolymer, etc. It is described that sufficient adhesion can be obtained by laminating on a recording layer.

  The protective layer coating solution thus prepared is applied onto the image recording layer provided on the support and dried to form a protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The method for applying the protective layer is not particularly limited, and a known method such as the method described in US Pat. No. 3,458,311 or Japanese Patent Publication No. 55-49729 can be applied. . Specific examples include a blade coating method, an air knife coating method, a gravure coating method, a roll coating coating method, a spray coating method, a dip coating method, and a bar coating method.

The coating amount of the protective layer, the coating amount after drying is preferably in the range of 0.01 to 10 g / m ^2, more preferably in the range of 0.02 to 3 g / m ^2, and most preferably 0. It is in the range of 02 to 1 g / m ² .

  Furthermore, other functions can be imparted to the protective layer. For example, by adding a colorant (for example, a water-soluble dye) that is excellent in the transparency of infrared rays used for exposure and that can efficiently absorb light of other wavelengths, safe light is not caused. Suitability can be improved.

  Since the lithographic printing plate precursor of the present invention provided with such an image recording layer uses the aluminum alloy plate of the present invention and the lithographic printing plate support, it is excellent in resistance to spot-like stains by performing development treatment. It becomes a lithographic printing plate.

(Examples 1-8, Comparative Examples 1-5)
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

1. Production of Aluminum Alloy Plate An aluminum alloy having the composition shown in Table 1 was subjected to semi-continuous casting (DC) or continuous casting (CC).
In semi-continuous casting, the formed ingot was chamfered, and then heat treatment, soaking, hot rolling, cold rolling, intermediate annealing, cold rolling and straightening were sequentially performed to obtain an aluminum alloy sheet. Table 1 shows the soaking temperature.
On the other hand, in continuous casting, hot rolling, cold rolling, intermediate annealing, cold rolling and straightening were sequentially performed to obtain an aluminum alloy sheet. The temperature of the intermediate annealing is shown in Table 1.

  The amount of Fe solid solution (mass%) of the obtained aluminum alloy plate and the contents of intermetallic compounds and Al—Fe-based intermetallic compounds were measured by the following methods. The results are shown in Table 1.

<Fe solid solution amount>
The amount of solid solution of Fe was obtained by dissolving the obtained aluminum alloy plate with hot phenol, filtering the dissolved matrix and the intermetallic compound as a residual residue, and further filtering the fine intermetallic compound in the filtrate with 10% quenching. It isolate | separated by extraction using an acid solution, and measured the amount of Fe in a subsequent filtrate with the ICP emission spectrometer.

<Contents of intermetallic compound and Al—Fe intermetallic compound>
The intermetallic compound contained in the aluminum alloy was measured by XRD.
Specifically, using an X-ray diffractometer RAD-rR (manufactured by Rigaku Corporation), the integration of Fe-based intermetallic compound phases (Al ₃ Fe, Al ₆ Fe, α-AlFeSi) detected under the following measurement conditions The diffraction intensity value (unit: Kcounts) was calculated.
・ Set tube voltage 50kV
・ Set tube current 200mA
・ Sampling interval 0.01 °
・ Scanning speed 1 ° / min ・ 2θ scanning range 10 ° ～ 70 °
・ Use of graphite monochromator

From the X-ray chart obtained by the measurement, integrated diffraction intensity values of Al ₃ Fe: 24.0 °, Al ₆ Fe: 18.0 °, α-AlFeSi: 42.0 ° were used.
Subsequently, the content of the Al—Fe-based intermetallic compound was calculated by the following formula.

  Al-Fe intermetallic compound content (% by mass) = {Fe content (% by mass) -Fe solid solution amount (% by mass)} × {(Al—Fe intermetallic compound phase peak detected by XRD Sum of integral diffraction intensities) / (total sum of integral diffraction intensities of Fe phase peaks detected by XRD)}

Here, the Al—Fe-based intermetallic compound indicates Al ₃ Fe and Al ₆ Fe, and the Fe-based phases indicate Al ₃ Fe, Al ₆ Fe, and α-AlFeSi. When no peak appeared, the integrated diffraction intensity was calculated as 0.1.

2. Production of Support for Lithographic Printing Plate Each aluminum alloy plate produced above was subjected to the treatment shown in Table 2 below among the following (A) to (C) to produce a lithographic printing plate support. In addition, the water washing process was performed between all the process steps, and the liquid draining was performed with the nip roller after the water washing process.

<Process (A)>
(Aa) Mechanical roughening treatment (brush grain method)
Using a device as shown in FIG. 3, a mechanical rough surface by a rotating bundle-planting brush while supplying a suspension of pumice (specific gravity 1.1 g / cm ³ ) as a polishing slurry to the surface of an aluminum plate. The treatment was performed. In FIG. 3, 1 is an aluminum plate, 2 and 4 are roller-like brushes (bundling brushes in this embodiment), 3 is an abrasive slurry, and 5, 6, 7 and 8 are support rollers.
In the mechanical surface roughening treatment, the median diameter (μm) of the abrasive was 30 μm, the number of brushes was 4, and the number of rotations (rpm) of the brushes was 250 rpm. The material of the bunch planting brush was 6 · 10 nylon, with a bristle diameter of 0.3 mm and a bristle length of 50 mm. The brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. The distance between the two support rollers (φ200 mm) at the bottom of the bundle-planting brush was 300 mm. The bundle brush was pressed until the load of the drive motor for rotating the brush became 10 kW plus with respect to the load before the bundle brush was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate.

(Ab) Alkaline etching treatment The aluminum plate obtained above was etched by spraying a caustic soda aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass% with a spray tube at a temperature of 70 ° C. . Then, water washing by spraying was performed. The amount of aluminum dissolved was 10 g / m ² .

(Ac) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in an aqueous nitric acid solution. The nitric acid aqueous solution used for the desmut treatment was a nitric acid waste solution used for electrochemical roughening in the next step. The liquid temperature was 35 ° C. The desmutting liquid was sprayed and sprayed for 3 seconds.

(Ad) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of nitric acid electrolysis 60 Hz. As the electrolytic solution at this time, an electrolytic solution in which aluminum nitrate was adjusted to 4.5 g / L by adding aluminum nitrate to an aqueous solution having a temperature of 35 ° C. and nitric acid of 10.4 g / L was used. The AC power supply waveform is the waveform shown in FIG. 1. The time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, and a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode. An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 2 was used. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode. Amount of electricity (C / dm ²⁾ the aluminum plate was 185C / dm ² as the total quantity of electricity when the anode. Then, water washing by spraying was performed.

(Ae) Alkaline etching treatment The aluminum plate obtained above was etched by spraying a caustic soda aqueous solution having a caustic soda concentration of 5 mass% and an aluminum ion concentration of 0.5 mass% with a spray tube at a temperature of 50C. . Then, water washing by spraying was performed. The amount of dissolved aluminum was 0.5 g / m ² .

(Af) Desmutting treatment in acidic aqueous solution Next, desmutting treatment was performed in an aqueous sulfuric acid solution. The sulfuric acid aqueous solution used for the desmut treatment was a solution having a sulfuric acid concentration of 300 g / L and an aluminum ion concentration of 5 g / L. The liquid temperature was 60 ° C. The desmutting liquid was sprayed and sprayed for 3 seconds.

(Ag) Electrochemical roughening treatment An electrochemical roughening treatment was continuously performed using an alternating voltage of hydrochloric acid electrolysis 60 Hz. As the electrolytic solution, an electrolytic solution in which aluminum chloride was adjusted to 4.5 g / L by adding aluminum chloride to an aqueous solution having a liquid temperature of 35 ° C. and hydrochloric acid of 6.2 g / L was used. The AC power supply waveform is the waveform shown in FIG. 2, the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell shown in FIG. 2 was used.
The current density was 25A / dm ² at the peak of electric current amount of hydrochloric acid electrolysis (C / dm ²⁾ the aluminum plate was 63C / dm ² as the total quantity of electricity when the anode. Then, water washing by spraying was performed.

(Ah) Alkaline etching treatment The aluminum plate obtained above was etched by spraying a caustic soda aqueous solution having a caustic soda concentration of 5 mass% and an aluminum ion concentration of 0.5 mass% with a spray tube at a temperature of 50C. . Then, water washing by spraying was performed. The amount of aluminum dissolved was 0.1 g / m ² .

(Ai) Desmutting treatment in acidic aqueous solution Next, using the waste liquid generated in the anodizing treatment step (dissolving 5 g / L of aluminum ions in sulfuric acid 170 g / L aqueous solution), desmutting at a liquid temperature of 35 ° C. for 4 seconds. Processed. The desmut treatment was performed in an aqueous sulfuric acid solution. The desmutting liquid was sprayed and sprayed for 3 seconds.

(Aj) Anodizing treatment Anodizing treatment was performed using an anodizing apparatus using direct current electrolysis having the structure shown in FIG. 4 to obtain a lithographic printing plate support. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 170 g / L and aluminum ions of 5 g / L. Direct current electrolysis was performed at an average current density of 20 A / dm ² , and anodization was performed so that an anodic oxide coating was 2.7 g / m ² . The liquid temperature was 40 ° C., the voltage was 5 to 30 V, and the time was 10 seconds.

(Ak) Silicate treatment In order to ensure the hydrophilicity of the non-image part, a silicate treatment was performed by dipping at 70 ° C. for 7 seconds using a 2.5 mass% No. 3 sodium silicate aqueous solution. The adhesion amount of Si was 10 mg / m ² . Then, water washing by spraying was performed.

<Process (B)>
(Ba) Etching treatment in an alkaline aqueous solution (first etching treatment)
The aluminum plate was etched by immersion in an aqueous solution having a sodium hydroxide concentration of 27 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C. The aluminum ion concentration was adjusted using sodium aluminate. The amount of aluminum dissolved on the surface that was later subjected to electrochemical graining was 1 g / m ² .
Then, water washing by spraying was performed.

(Bb) Desmutting treatment in acidic aqueous solution (first desmutting treatment)
Next, desmut treatment was performed in an acidic aqueous solution. The acidic aqueous solution used for the desmutting treatment was an aqueous solution of 150 g / L sulfuric acid (liquid temperature 35 ° C.), and the desmutting time due to immersion was 5 seconds.
Then, the water washing process was performed.

(Bc) Electrochemical surface roughening treatment in aqueous hydrochloric acid solution Next, an electrolytic solution having a hydrochloric acid concentration of 14 g / L, an aluminum ion concentration of 13 g / L, and a sulfuric acid concentration of 3 g / L is used and electrolysis is performed using an alternating current. A roughening treatment was performed. The liquid temperature of the electrolytic solution was 30 ° C. The aluminum ion concentration was adjusted by adding aluminum chloride.
The waveform of the alternating current is a sine wave in which positive and negative waveforms are symmetrical, the frequency is 50 Hz, the anode reaction time and the cathode reaction time in one cycle of the alternating current are 1: 1, and the current density is the peak current value of the alternating current waveform. It was 75 A / dm ² . The amount of electricity is 450 C / dm ² in terms of the total amount of electricity left by the aluminum plate for the anodic reaction, and the electrolytic treatment was performed four times at intervals of 125 C / dm ^{2 for} 4 seconds. A carbon electrode was used as the counter electrode of the aluminum plate.
Then, the water washing process was performed.

(Bd) Etching treatment in alkaline aqueous solution (second etching treatment)
Aluminum on the surface subjected to electrochemical roughening treatment using an aqueous solution of 5% by weight of sodium hydroxide, 0.5% by weight of aluminum ions and a temperature of 35 ° C. Etching treatment by dipping was performed so that the dissolution amount of was 0.1 g / m ² . The aluminum ion concentration was adjusted using sodium aluminate.
Then, the water washing process was performed.

(Be) Desmutting treatment in acidic aqueous solution (second desmutting treatment)
Next, a desmut treatment in an acidic aqueous solution was performed. The acidic aqueous solution used for the desmutting treatment was performed by using the waste liquid generated in the anodizing treatment step (dissolving 5.0 g / L of aluminum ions in a 170 g / L aqueous solution of sulfuric acid) and immersing it at a liquid temperature of 30 ° C. for 5 seconds.

(Bf) Anodizing treatment Next, anodizing treatment was performed using an anodizing apparatus.
As an electrolytic solution, an electrolytic solution (temperature 45 ° C.) in which aluminum sulfate was dissolved in a 170 g / L sulfuric acid aqueous solution to make an aluminum ion concentration 5 g / L was used. Anodization was carried out at a current density of 30 A / dm ^{2 so} that the amount of the anodized film was 2.7 g / m ² . A carbon electrode was used as the counter electrode of the aluminum plate.
Then, it washed with water.

(Bg) Hydrophilization treatment The aluminum plate after the anodizing treatment was immersed in a 1.0 mass% aqueous solution of sodium silicate No. 3 (liquid temperature 22 ° C.) for 8 seconds. The amount of Si on the surface of the aluminum plate measured with a fluorescent X-ray analyzer was 3.5 mg / m ² .
Thereafter, the plate was washed with water, drained with a nip roller, and further dried by blowing air at 90 ° C. for 10 seconds to obtain a lithographic printing plate support.

<Process (C)>
(Aa) The treatment (A) is the same as the treatment (A) except that the mechanical roughening treatment is not performed and the total amount of electricity in the (Ad) electrochemical roughening treatment is changed to 220 C / dm ^2. A lithographic printing plate support was obtained in the same manner.

3. Production of lithographic printing plate precursor The following undercoating liquid was applied to each lithographic printing plate support produced as described above so that the dry coating amount was 28 mg / m ² to provide an undercoating layer.

<Coating liquid for undercoat layer>
-Undercoat layer compound (1) having the following structure: 0.18 g
・ Hydroxyethyliminodiacetic acid 0.10g
・ Methanol 55.24g
・ Water 6.15g

Next, the image recording layer coating solution is bar-coated on the undercoat layer formed as described above, and then oven-dried at 100 ° C. for 60 seconds to form an image recording layer having a dry coating amount of 1.3 g / m ^2. did.
All the image recording layer coating solutions were obtained by mixing and stirring the respective photosensitive solutions and microgel solutions immediately before coating.

<Photosensitive solution>
-Binder polymer (1) [The following structure: (E) component] 0.24g
Infrared absorber (1) [the following structure: component (A)] 0.030 g
-Radical polymerization initiator (1) [the following structure: component (B)] 0.162 g
Polymerizable compound [component (C)] tris (acryloyloxyethyl) isocyanurate (NK ester A-9300, manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.192 g
・ Low molecular weight hydrophilic compound tris (2-hydroxyethyl) isocyanurate
0.062g
・ Low molecular weight hydrophilic compound (1) [the following structure] 0.052 g
-Sensitizing agent Phosphonium compound (1) [the following structure] 0.055 g
・ Sensitizer Benzyl-dimethyl-octylammonium ・ PF ₆ salt 0.018g
-Betaine derivative (C-1) 0.010 g
・ Fluorosurfactant (1) [The following structure] 0.008g
・ Methyl ethyl ketone 1.091g
・ 1-methoxy-2-propanol 8.609g

<Microgel solution>
・ Microgel (1) 2.640 g
・ Distilled water 2.425g

  The structures of the binder polymer (1), the infrared absorber (1), the radical polymerization initiator (1), the phosphonium compound (1), the low molecular weight hydrophilic compound (1) and the fluorine-based surfactant (1) are as follows: It is as shown below.

  The microgel (1) described above is synthesized as follows.

<Synthesis of Microgel (1)>
2. As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Takenate D-110N, manufactured by Mitsui Takeda Chemical Co., Ltd.) 10 g, pentaerythritol triacrylate [(C) component] (SR444, manufactured by Nippon Kayaku Co., Ltd.) 15 g and 0.1 g of Piionin A-41C (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in 17 g of ethyl acetate. As an aqueous phase component, 40 g of a 4% by mass aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12,000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 50 ° C. for 3 hours. The microgel solution thus obtained was diluted with distilled water to a solid content concentration of 15% by mass, and this was designated as the microgel (1). When the average particle size of the microgel was measured by a light scattering method, the average particle size was 0.2 μm.

Then, a protective layer coating solution having the following composition was further bar-coated on the image recording layer formed as described above, and then oven-dried at 120 ° C. for 60 seconds to provide a dry coating amount of 0.15 g / m ² . A layer was formed to obtain a lithographic printing plate precursor.

<Coating liquid for protective layer>
・ Inorganic layered compound dispersion (1) 1.5 g
-Polyvinyl alcohol (CKS50, sulfonic acid modification, saponification degree 99 mol% or more, polymerization degree 300, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 6% by mass aqueous solution 0.55 g
-Polyvinyl alcohol (PVA-405, saponification degree 81.5 mol% polymerization degree 500, Kuraray Co., Ltd.) 6 mass% aqueous solution 0.03g
-1% by weight aqueous solution of surfactant (Emalex 710, manufactured by Nippon Emulsion)
8.60g
・ Ion-exchanged water 6.0g

  The inorganic layered compound dispersion (1) described above is prepared as follows.

(Preparation of inorganic layered compound dispersion (1))
6.4 g of synthetic mica Somasif ME-100 (manufactured by Coop Chemical Co., Ltd.) was added to 193.6 g of ion-exchanged water, and dispersed using an homogenizer until the average particle size (laser scattering method) became 3 μm. The aspect ratio of the obtained dispersed particles was 100 or more.

4). Evaluation of Potty Stain The obtained lithographic printing plate precursor was conditioned with interleaf for 1 hour in an environment of 25 ° C. and 70% RH, packaged with aluminum kraft paper, and then heated in an oven set at 60 ° C. Heating was performed for days.
Thereafter, the temperature was lowered to room temperature, and then the plate was attached to the plate cylinder of the printing machine LITHRONE 26 (manufactured by Komori Corporation) without developing.
Standard automatic of LITHRONE26 using dampening water of Equality-2 (manufactured by Fujifilm) / tap water = 2/98 (volume ratio) and Values-G (N) black ink (manufactured by Dainippon Ink & Chemicals, Inc.) After supplying dampening water and ink by the printing start method and developing on the machine, 500 sheets were printed on Tokishi Art (76.5 kg) paper.

The 500th printed matter was visually confirmed, and the number of print stains of 20 μm or more per 100 cm ² was calculated. The results are shown in Table 2.
If the number of stains is 200 or less per 100 cm ² , it can be evaluated as having excellent resistance to severe stains.

  As shown in Tables 1 and 2, it can be seen that as the content of the Al—Fe-based intermetallic compound decreases, the anti-spot resistance is improved. As described above, this is the basis for supporting the new finding that Al—Fe-based intermetallic compounds are the starting point of corrosion of aluminum alloy sheets.

It is a graph which shows an example of the alternating waveform current waveform figure used for the electrochemical roughening process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a side view which shows an example of the radial type cell in the electrochemical roughening process using alternating current in the manufacturing method of the support body for lithographic printing plates of this invention. It is a side view which shows the concept of the process of the brush graining used for the mechanical roughening process in preparation of the support body for lithographic printing plates of this invention. It is the schematic of the anodizing apparatus used for the anodizing process in preparation of the support body for lithographic printing plates of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum plate 2, 4 Roller-like brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller ta Anode reaction time tc Cathode reaction time tp Time until electric current reaches a peak from 0 Ia Current at peak on anode cycle side Ic Current at peak on the cathode cycle side 50 Main electrolytic cell 51 AC power supply 52 Radial drum rollers 53a, 53b Main electrode 54 Electrolyte supply port 55 Electrolytic solution 56 Auxiliary anode 60 Auxiliary anode tank W Aluminum plate 610 Anodizing apparatus 612 Power supply Tank 614 Electrolytic treatment tank 616 Aluminum plate 618, 626 Electrolyte 620 Feed electrode 622, 628 Roller 624 Nip roller 630 Electrode electrode 632 Tank wall 634 DC power source

Claims (11)

An aluminum alloy plate containing 0.08 to 0.45 mass% Fe, 0.05 to 0.20 mass% Si, and the balance consisting of inevitable impurities and Al,
Der content is more than 0.05 mass% of Al-Fe intermetallic compound is,
An aluminum alloy plate for a lithographic printing plate, wherein a main component of an intermetallic compound present in the aluminum alloy plate is α-AlFeSi . 2. The aluminum alloy plate for a lithographic printing plate according to claim 1, wherein a ratio (Fe / Si) of Fe content and Si content of the aluminum alloy is 0.5 to 2.2. The aluminum alloy plate for lithographic printing plates according to claim 1 or 2 , wherein the Zn content is 0.01 mass% or less. The aluminum alloy plate for lithographic printing plates according to any one of claims 1 to 3 , wherein the Mg content is 0.20 mass% or less. It is a manufacturing method of the aluminum alloy plate for lithographic printing plates which manufactures the aluminum alloy plate for lithographic printing plates in any one of Claims 1-4 ,
A semi-continuous casting process for forming an ingot from molten aluminum alloy;
A chamfering process for chamfering the ingot obtained in the semi-continuous casting process;
A method for producing an aluminum alloy plate for a lithographic printing plate, comprising: a soaking treatment in which a soaking treatment is performed in a temperature range of 500 to 550 ° C after the chamfering step. It is a manufacturing method of the aluminum alloy plate for lithographic printing plates which manufactures the aluminum alloy plate for lithographic printing plates in any one of Claims 1-4 ,
A continuous casting step of forming an aluminum alloy sheet by rolling while solidifying the molten aluminum alloy;
A cold rolling step for reducing the thickness of the aluminum alloy plate obtained in the continuous casting step;
After the cold rolling step, an intermediate annealing step in which heat treatment is performed at a temperature of 500 ° C. or lower,
A method for producing an aluminum alloy plate for a lithographic printing plate, comprising: a finish cold rolling step for reducing the thickness of the aluminum alloy plate after the intermediate annealing. A lithographic printing plate obtained by subjecting the surface of an aluminum alloy plate for a lithographic printing plate according to any one of claims 1 to 4 to roughening treatment including electrochemical roughening treatment and anodizing treatment in this order. Support. A lithographic printing plate support obtained by further hydrophilizing after the anodizing treatment,
The hydrophilic treatment, a lithographic printing plate support according to claim 7 adsorbed amount of silicon is treated using an alkali metal silicate such that the 1.0~30mg / m ^2. A lithographic printing plate precursor comprising an image recording layer provided on the lithographic printing plate support according to claim 7 or 8 . Wherein the image recording layer, anionic and / or PF ₆ consisting halide ions ^- The lithographic printing plate precursor as claimed in claim 9 having a. The lithographic printing plate precursor according to claim 9 or 10 , wherein the image recording layer is an image recording layer which forms an image by exposure and the non-exposed portion can be removed by printing ink and / or fountain solution.

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