JP2011047019A - Aluminum alloy sheet for planographic printing plate and support for planographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum alloy sheet for a planographic printing plate, which can provide a support for the planographic printing plate having a homogeneous roughened surface even when electrolyzed by various conditions of electrolytic roughening treatment, and can provide the planographic printing plate superior in printing durability and resistance to dirt; the support for the planographic printing plate using the same; and an original plate of the planographic printing plate. <P>SOLUTION: The aluminum alloy sheet for the planographic printing plate includes 0.03-0.20 mass% Si and 0.11-0.45 mass% Fe. The quantity of dissolved Si is 120-600 ppm, and the quantity of dissolved Fe is 100 ppm or less. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

Conventionally, photosensitive lithographic printing plate precursors using an aluminum alloy plate as a support have been widely used for offset printing.
In general, a rolled plate having a thickness of 0.1 to 0.5 mm is used for the aluminum alloy plate, and magnesium (Mg) or manganese (manganese (Mg) or manganese ( A material added with a small amount of (Mn) is used.

On the other hand, as a method for producing a lithographic printing plate support, a method is generally known in which a surface of a sheet-like or coil-like aluminum alloy plate is subjected to a roughening treatment and an anodizing treatment.
Further, as a method for producing a lithographic printing plate precursor, a method is generally known in which a photosensitive solution is applied on a lithographic printing plate support and dried to form an image recording layer, and then cut to a desired size as necessary. ing. The lithographic printing plate precursor is developed into a lithographic printing plate by being developed after image printing.

  In this method, in order to improve the adhesion between the image recording layer and the lithographic printing plate support, it is also referred to as an electrochemical roughening treatment (hereinafter referred to as “electrolytic roughening treatment”) performed in an acidic solution. It is known that it is effective to apply a surface treatment or an undercoat liquid after anodizing.

Moreover, when performing the roughening process including the electrolytic roughening process, it is known that minute irregularities (pits) are generated on the surface of the lithographic printing plate support by the roughening process.
Here, it is considered that a lithographic printing plate precursor excellent in printing performance (particularly printing durability and stain resistance) can be obtained by increasing the pit diameter uniformly and increasing the pit depth. It was. This is because in the image part, the adhesion between the image recording layer and the lithographic printing plate support becomes strong, so even if a large number of sheets are printed, the image recording layer is difficult to peel off. This is based on the knowledge that a large amount of fountain solution can be retained on the surface, so that contamination is less likely to occur.
From such a viewpoint, the shape of the pits generated by the electrolytic surface roughening treatment, and the surface of the lithographic printing plate support after the electrolytic surface roughening treatment (hereinafter also referred to as “electrolytic roughened surface”). ) Have been proposed (see, for example, Patent Documents 1 to 8).

JP 2000-108534 A JP 2000-37965 A JP 2000-37964 A JP-A-7-173563 JP 2005-89846 A JP 2007-21519 A JP 2008-111142 A JP-A-7-138687

  Among these patent documents, particularly in Patent Document 7, the contents and solid solution amounts of silicon (Si) and iron (Fe) of the aluminum alloy plate for lithographic printing plates are in a specific range. Depending on the treatment conditions, the surface of the lithographic printing plate support after the electrolytic surface roughening treatment (hereinafter, also referred to as “electrolytic roughened surface”) may not be uniform. A lithographic printing plate using a printing plate support is inferior in printing durability and stain resistance.

  Accordingly, the present invention can provide a lithographic printing plate support having a uniform electrolytic roughened surface even under various electrolytic roughening treatment conditions, and is excellent in printing durability and stain resistance. An object of the present invention is to provide an aluminum alloy plate for a lithographic printing plate from which a printing plate can be obtained, a lithographic printing plate support and a lithographic printing plate precursor using the same.

As a result of earnest research to achieve the above object, the present inventor has made various electrolytic surface roughening treatment conditions by using an aluminum alloy plate for a lithographic printing plate having a specific content and solid solution content of Si and Fe. Found that a lithographic printing plate support having a uniform electrolytic roughened surface can be obtained, and that a lithographic printing plate excellent in printing durability and stain resistance can be obtained. I let you.
That is, the present invention provides the following (1) to (8).

  (1) It contains 0.03-0.20 mass% Si and 0.11-0.45 mass% Fe, the solid solution amount of Si is 120-600 ppm, and the solid solution amount of Fe is 100 ppm. An aluminum alloy plate for a lithographic printing plate, which is the following.

(2) The aluminum alloy plate for a lithographic printing plate as described in (1) above, wherein the surface has 20000 pieces / mm ² or more of intermetallic compounds having an equivalent circle diameter of 0.2 μm or more.

  (3) The aluminum alloy plate for a lithographic printing plate as described in (1) or (2) above, wherein the Cu content is 0.030% by mass or less.

  (4) Said (1) obtained by continuous casting which supplies aluminum alloy molten metal between a pair of cooling rollers via a molten metal supply nozzle, and performs rolling while solidifying said aluminum alloy molten metal with said pair of cooling rollers. The aluminum alloy plate for lithographic printing plates as described in any one of-(3).

  (5) For a lithographic printing plate obtained by subjecting the surface of an aluminum alloy plate for a lithographic printing plate according to any one of (1) to (4) above to a roughening treatment including an electrochemical roughening treatment Support.

  (6) The lithographic printing plate support according to (5), wherein the roughening treatment further includes an alkali etching treatment before the electrochemical roughening treatment.

  (7) The lithographic printing plate support according to (5) or (6), wherein the roughening treatment further includes an alkali etching treatment after the electrochemical roughening treatment.

  (8) A lithographic printing plate precursor comprising an image recording layer provided on the lithographic printing plate support according to any one of (5) to (7) above.

  As described below, according to the present invention, a lithographic printing plate support having a uniform electrolytic roughened surface can be obtained even under various electrolytic roughening treatment conditions, and printing durability and An aluminum alloy plate for a lithographic printing plate capable of obtaining a lithographic printing plate excellent in stain resistance, a lithographic printing plate support and a lithographic printing plate precursor using the same can be provided.

  Moreover, the aluminum alloy plate for lithographic printing plates of the present invention is very useful because it can simplify the production process and reduce the production cost and production time as compared with the conventional method.

Furthermore, by using an aluminum alloy plate for a lithographic printing plate having 20000 pieces / mm ² or more of intermetallic compounds having an equivalent circle diameter of 0.2 μm or more on the surface, lithographic printing with better uniformity of the electrolytic roughened surface A plate support can be obtained.
This is based on a new finding that the inventor becomes an effective reaction starting point when an intermetallic compound is subjected to electrochemical surface roughening.

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 the schematic of the anodizing apparatus used for the anodizing process in the manufacturing method of the support body for lithographic printing plates of this invention. It is a graph which shows an example of the sine 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 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.

Hereinafter, the present invention will be described in detail.
[Support for lithographic printing plate]
<Aluminum alloy plate (rolled aluminum)>
The lithographic printing plate support of the present invention uses the lithographic printing plate aluminum alloy plate (hereinafter referred to as “the aluminum alloy plate of the present invention”) described below. The essential alloy components in the aluminum alloy are Al, Fe, and Si, and may contain copper (Cu) as an optional component.
The inventor pays particular attention to the amount of solid solution, and it is possible to maintain the solid solution amount of Si and Fe within a certain range when performing an electrolytic surface roughening treatment on an aluminum alloy plate produced by continuous casting. It has been found that it exhibits an excellent effect on the stability of the treatment.

  Si is an element contained as an inevitable impurity in an Al ingot, which is a raw material, in an amount of about 0.03 to 0.1% by mass, and is often intentionally added in a small amount to prevent variation due to a difference in raw materials. Si exists as a solid solution in aluminum, or as an intermetallic compound or a single precipitate.

In the present invention, the Si content is 0.03 to 0.20% by mass, preferably 0.04 to 0.18% by mass, and 0.05 to 0.15% by mass. More preferred.
When the Si content is within this range, the necessary amount of Si solid solution is ensured, and even when anodizing is performed after electrolytic surface roughening, defects in the anodized film are unlikely to occur. Thus, the stain resistance as a lithographic printing plate is also improved.

In the present invention, the solid solution amount of Si is 120 to 600 ppm, preferably 150 to 600 ppm, and more preferably 150 to 500 ppm.
When the solid solution amount of Si is within this range, the electrolytic roughened surface becomes uniform, and pits having average opening diameters of 0.01 to 0.05 μm and 0.05 to 1.5 μm are uniform over the entire surface. Formed.

  Fe is an element that hardly dissolves in aluminum and remains as an intermetallic compound.

In the present invention, the Fe content is 0.11 to 0.45 mass%, preferably 0.15 to 0.45 mass%, and preferably 0.20 to 0.43 mass%. More preferred.
When the Fe content is within this range, Fe is dispersed as a fine intermetallic compound, and these act as starting points for the electrolytic surface roughening treatment, so that the electrolytic surface roughened surface becomes uniform.

In the present invention, from the viewpoint of securing a necessary intermetallic compound of Fe, the solid solution amount of Fe is 100 ppm or less, preferably 50 ppm or less, and more preferably 40 ppm or less.
Further, from the viewpoint of ensuring the heat resistance of the aluminum alloy plate, the solid solution amount of Fe is preferably 10 ppm or more.

Cu is an important element in controlling the electrolytic surface roughening treatment, but is an optional element in the present invention.
In the present invention, from the viewpoint of maintaining the uniformity of electrolytic surface roughening, the content when Cu is contained is preferably 0.030% by mass or less.

  Since the grain refinement element does not affect the uniformity of the electrolytic surface roughening, it may be added as appropriate to prevent cracking during casting. Therefore, for example, Ti can be added in a range of 0.05% by mass or less, and B can be added in a range of 0.02% by mass or less.

The balance of the aluminum alloy plate is made of Al and inevitable impurities.
As this inevitable impurity, Mg, Mn, Zn, Cr, Zr, V, Zn, Be etc. are mentioned, for example, These may each be contained 0.05 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.

As described above, the present inventor uses an aluminum alloy plate containing a specific amount of Si and Fe as a continuous cast rolled material, and sets the solid solution amount of Si and Fe to a specific value. It has been found that the stability is improved and the uniformity of the electrolytic roughened surface can be enhanced.
Thereby, in the present invention, a lithographic printing plate support having a uniform electrolytic roughened surface can be obtained even under various electrolytic roughening treatment conditions, and excellent in printing durability and stain resistance. A lithographic printing plate can be obtained.

In addition, as described above, the present inventor has newly found that an intermetallic compound is an effective reaction starting point for electrochemical surface roughening, and a metal having a circle equivalent diameter of 0.2 μm or more on the surface. It has been found that by using an aluminum alloy plate for a lithographic printing plate having 20000 pieces / mm ² or more of intermetallic compounds, the uniformity of the electrolytic roughened surface becomes better.
Here, in the aluminum alloy plate of the present invention in which Si and Fe are essential, as the intermetallic compound, specifically, for example, Al ₃ Fe, Al ₆ Fe, Al _m Fe, α-AlFeSi, β -AlFeSi etc. are mentioned.

In the present invention, regardless of the type of intermetallic compound, by having 20000 / mm ² or more of intermetallic compounds having an equivalent circle diameter of 0.2 μm or more, the uniformity of the electrolytic roughened surface is better. Become. This is considered to be because the diameter and depth of the pits formed by the roughening treatment are uniform because there are a large number of intermetallic compounds serving as starting points for the electrolytic roughening treatment.
Moreover, it is preferable to have 30000-60000 pieces / mm ² of intermetallic compounds having an equivalent circle diameter of 0.2 μm or more, for the reason that the uniformity of the electrolytic roughened surface is further improved. 35000-60000 pieces / mm ² More preferably.
Furthermore, for the same reason, the average diameter of the intermetallic compound is preferably 0.2 to 1.0 [mu] m, and more preferably 0.3 to 0.5 [mu] m.

Here, the number of intermetallic compounds and the average diameter are measured by the following methods.
First, an aluminum alloy plate obtained by wiping off the oil on its surface with acetone is used as a measurement sample.
Next, using a scanning electron microscope (PC-SEM7401F, manufactured by JEOL Ltd.), a reflected electron image on the surface of the aluminum alloy plate is taken under the conditions of an acceleration voltage of 12.0 kV and a magnification of 2000 times.
Subsequently, five images arbitrarily selected from the obtained reflected electron images are stored in JPEG format, and converted into bmf (bitmap file) format using MS-Paint (manufactured by Microsoft).
This bmf format file is stored in the image analysis software ImageFactory Ver. 3.2 After reading into the Japanese version (Asahi Hitech Co., Ltd.) and performing image analysis, static binarization processing of the image is performed, and the portion corresponding to the white intermetallic compound is counted as a feature value. Specify the equivalent circle diameter (equivalent circle diameter) to obtain the particle size distribution.
From the result of this particle size distribution, the number of intermetallic compounds having an equivalent circle diameter of 0.2 μm or more is calculated. This calculation is performed by rounding the average value of the numbers calculated from each of the five image data (particle size distributions) to the nearest hundred.
Similarly, from the result of the particle size distribution, the average value of the equivalent circle diameters of the intermetallic compounds is calculated as the average diameter.
In addition, the number of intermetallic compounds is the same on the back surface of the aluminum alloy plate not subjected to the roughening treatment after the roughening treatment is performed and the lithographic printing plate support or the lithographic printing plate precursor is produced. Can be measured.

Furthermore, the present inventor has found that the amount of Fe and Si in the aluminum alloy plate and the size and number of intermetallic compounds can be set to appropriate values by setting the heat treatment temperature and time to appropriate values. .
In the present invention, in order to obtain an aluminum alloy plate suitable for an electro-roughened lithographic printing plate support, a continuous casting and rolling method is used, and the solid solution amount of Fe and Si, the size of the intermetallic compound, and The number is preferably a specific value.

The aluminum alloy sheet of the present invention is obtained by continuous casting in which molten aluminum alloy is supplied between a pair of cooling rollers via a molten metal supply nozzle, and rolling is performed while the molten aluminum alloy is solidified by the pair of cooling rollers. Is preferred.
Rolling by continuous casting has a high solidification rate on the surface of the cast material, so that the crystallized material is fine and uniform, does not require the homogenization heat treatment of the ingot required by the DC casting method, and is not subjected to long-time processing. Therefore, it is suitable as a base plate for a lithographic printing plate support.

Specifically, the following method is preferably exemplified.
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 gas such as hydrogen in the molten metal (eg flux treatment using argon gas, chlorine gas, etc.); ceramic tube filter, ceramic foam filter, etc. Examples include 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 combining such a degassing process and a filtering process.

  These cleaning treatments are preferably performed in order to prevent defects caused by foreign matters such as non-metallic inclusions and oxides in the molten metal and defects caused by gas dissolved in the molten metal. Regarding filtering of the molten metal, JP-A-6-57432, JP-A-3-162530, JP-A-5-140659, JP-A-4-231425, JP-A-4-276031, JP-A-5-311261, JP-A-5-311261 6-136466 and the like. Further, the degassing of the molten metal is described in JP-A-5-51659, Japanese Utility Model Laid-Open No. 5-49148, and the like. The present applicant has also proposed a technique relating to degassing of molten metal in Japanese Patent Application Laid-Open No. 7-40017.

Next, continuous casting is performed using a molten metal that has been subjected to a cleaning treatment as necessary.
Continuous casting is a process in which a molten aluminum alloy is supplied between a pair of cooling rollers via a molten metal supply nozzle, and rolling is performed while the molten aluminum alloy is solidified by the pair of cooling rollers. Method), a method using a cooling roll represented by the 3C method, a double belt method (Hasley method), a method using a cooling belt or a cooling block represented by the Al-Swiss Caster II type, and the like.
Since the continuous casting method generally has a higher cooling rate than the DC casting method, it has a feature that the solid solubility of the alloy component in the aluminum matrix can be increased. Moreover, it solidifies in the range whose cooling rate is 100-1000 degrees C / sec.
Regarding the continuous casting method, the techniques proposed by the present applicant are disclosed in JP-A-3-79798, JP-A-5-201166, JP-A-5-156414, JP-A-6-262203, and JP-A-6-122949. JP-A-6-210406 and JP-A-6-26308.

In continuous casting, for example, if a method using a cooling roll such as a Hunter method is used, a cast plate having a thickness of 1 to 10 mm can be directly continuously cast, and the hot rolling step can be omitted. Benefits are gained.
In addition, when a method using a cooling belt such as the Husley method is used, a cast plate having a thickness of 10 to 50 mm can be cast. Generally, a hot rolling roll is arranged immediately after casting and continuously rolled. Thus, a continuous cast and rolled plate having a thickness of 1 to 10 mm is obtained.
In the present invention, from the viewpoint of generating a large number of intermetallic compounds, a method using a cooling roll is preferable, and the plate thickness is preferably 7 mm or less.

  After the continuous casting, the obtained aluminum alloy plate is finished to a predetermined thickness, for example, a thickness of 0.1 to 0.5 mm, through a cold rolling process or the like applied as necessary.

In the present invention, intermediate annealing treatment may be performed from the viewpoint of increasing the Si solid solution amount or suppressing the Fe solid solution amount before, after, or during the cold rolling. Further, the appropriate intermediate annealing treatment has an effect of making the crystal grains fine, and the surface quality can be improved.
From the viewpoint of optimizing the size and number of intermetallic compounds, it is desirable to avoid the intermediate annealing treatment from being performed at an excessively high temperature or excessively for a long time. In particular, it is desirable to avoid heat treatment exceeding 550 ° C. or heat treatment exceeding 36 hours. This is because the intermetallic compound is re-dissolved in aluminum, or the metastable intermetallic compound such as Al ₆ Fe, Al _m Fe, α-AlFeSi, β-AlFeSi is changed to the stable phase Al ₃ Fe. This is because the number may decrease during the process.
As a suitable condition for the intermediate annealing treatment, a batch annealing furnace is used at 280 to 550 ° C. for 2 to 20 hours, preferably 350 to 550 ° C. for 2 to 10 hours, more preferably 350 to 550 ° C. for 2 to 5 hours. Conditions for heating for a period of time; conditions for heating at 400 to 550 ° C. for 6 minutes or less, preferably 450 to 550 ° C. for 2 minutes or less using a continuous annealing furnace;

The flatness of the aluminum alloy plate finished to a predetermined thickness, for example, 0.1 to 0.5 mm by the above steps 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 in order to improve productivity, it is preferably performed in a continuous coil state.
Further, a slitter line may be used for processing into a predetermined plate width.
Furthermore, in order to prevent the 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.

<Roughening treatment>
The lithographic printing plate support of the present invention is roughened on the surface of an aluminum alloy plate obtained through the above-described continuous casting process and various processes (for example, an intermediate annealing process, a cold rolling process, etc.) performed as desired. It is obtained by processing.
As the roughening treatment, generally one or a combination of two or more of mechanical roughening treatment, chemical roughening treatment and electrochemical roughening treatment is used.
In the present invention, as the surface roughening treatment, it is preferable to perform at least electrolytic surface roughening treatment and to perform alkali etching treatment (first alkali etching treatment) before the electrolytic surface roughening treatment. It is preferable to perform an alkali etching process (second alkali etching process) later.

As the surface roughening treatment, electrochemical surface roughening treatment is preferably performed twice, and an etching treatment in an alkaline aqueous solution is preferably performed between them. 1 alkali etching treatment), desmutting treatment in acidic aqueous solution (first desmutting treatment), electrochemical roughening treatment in aqueous solution containing nitric acid or hydrochloric acid (first electrolytic roughening treatment), in alkaline aqueous solution Etching treatment (second alkali etching treatment), desmutting treatment in acidic aqueous solution (second desmutting treatment), electrochemical surface roughening treatment in aqueous solution containing hydrochloric acid (second electrolytic surface roughening treatment) Etching treatment in alkaline aqueous solution (third alkaline etching treatment), desmutting treatment in acidic aqueous solution (third desmutting treatment), and anodizing treatment in this order Be treated are preferably exemplified.
Moreover, it is preferable to perform a mechanical surface roughening process before the said alkali etching process (1st alkali etching process).
Furthermore, it is also preferable to perform sealing treatment and hydrophilization treatment after the anodizing treatment.

In the method for producing a lithographic printing plate support of the present invention, various steps other than those described above may be included.
Hereinafter, each step of the surface treatment will be described in detail.

<Mechanical roughening>
In this invention, it is preferable to perform the mechanical roughening process performed in order to make the center average surface roughness of the surface of an aluminum alloy plate 0.35-1.0 micrometer.
Hereinafter, the brush grain method used suitably as a mechanical roughening process is demonstrated.

The brush grain method generally uses a roller-shaped brush in which a large number of brush hairs such as synthetic resin hair made of synthetic resin such as nylon (trade name), propylene, and vinyl chloride resin are implanted on the surface of a cylindrical body. This is performed by rubbing one or both of the surfaces of the aluminum alloy plate while spraying a slurry liquid containing an abrasive on a rotating roller brush.
Instead of the roller brush and the slurry liquid, a polishing roller which is a roller having a polishing layer on the surface can be used.

When a roller brush is used, the flexural modulus is preferably 10,000 to 40,000 kg / cm ² , more preferably 15,000 to 35,000 kg / cm ² , and the bristle strength is preferably Brush hair that is 500 g or less, more preferably 400 g or less is used. The diameter of the brush bristles is generally 0.2 to 0.9 mm. The length of the brush bristles can be appropriately determined according to the outer diameter of the roller brush and the diameter of the body, but is generally 10 to 100 mm.
In the present invention, it is preferable to use a plurality of nylon brushes, specifically, 3 or more are more preferable, and 4 or more are particularly preferable. By adjusting the number of brushes, the wavelength component of the recess formed on the aluminum alloy plate surface can be adjusted.

  Further, the load of the drive motor that rotates the brush is preferably 1 kW plus or more, more preferably 2 kW plus or more, and particularly preferably 8 kW plus or more with respect to the load before the brush roller is pressed against the aluminum alloy plate. By adjusting the load, the depth of the recess formed on the surface of the aluminum alloy plate can be adjusted. The number of rotations of the brush is preferably 100 or more, and particularly preferably 200 or more.

A well-known thing can be used for an abrasive | polishing agent. For example, abrasives such as pumice stone (pumice stone), silica sand, aluminum hydroxide, alumina powder, silicon carbide, silicon nitride, volcanic ash, carborundum, and gold sand; a mixture thereof can be used. Of these, pumiston and silica sand are preferable. Quartz sand is harder than pumicestone and is less likely to break, so it has better surface roughening efficiency. Further, aluminum hydroxide is suitable for the case where it is not desired to locally generate deep recesses because particles are damaged when an excessive load is applied.
The median diameter of the abrasive is preferably from 2 to 100 μm, more preferably from 20 to 60 μm, from the viewpoint of excellent surface roughening efficiency and the ability to narrow the graining pitch. By adjusting the median diameter of the abrasive, the depth of the recess formed on the aluminum alloy plate surface can be adjusted.

For example, the abrasive is suspended in water and used as a slurry. In addition to the abrasive, the slurry liquid may contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like. The specific gravity of the slurry liquid is preferably 0.5-2.
As an apparatus suitable for the mechanical surface roughening treatment, for example, an apparatus described in Japanese Patent Publication No. 50-40047 can be given.

  As for details of an apparatus for performing a mechanical surface roughening process using a brush and an abrasive, those described in JP-A-2002-2111159 can be used by the present applicant.

  Examples of the mechanical surface roughening process other than the brush grain method include a process of forming irregularities on the surface by transfer at the end of the cold rolling described above. In the present invention, instead of the brush grain method, or a brush Can be applied together with the grain method.

<First alkali etching treatment>
The first alkali etching treatment is a treatment for dissolving the surface layer by bringing the aluminum alloy plate into contact with an alkali solution.

The first alkali etching treatment performed before the electrolytic surface roughening treatment (first electrolytic surface roughening treatment) is to smooth the uneven shape when the mechanical surface roughening is performed. When forming a uniform recess by the treatment (first electrolytic surface roughening treatment) and when mechanical surface roughening is not performed, the rolling oil, dirt, natural oxide film, etc. on the surface of the aluminum alloy plate are removed. It is done for the purpose of doing.
In the first alkali etching treatment, the etching amount is preferably 0.1 g / m ² or more, more preferably 0.5 g / m ² or more, and further preferably 1 g / m ² or more. Further, it is preferably 12 g / m ² or less, more preferably 10 g / m ² or less, and still more preferably 8 g / m ² or less. When the lower limit of the etching amount is within the above range, uniform pits can be generated in the electrolytic surface roughening treatment (first electrolytic surface roughening treatment), and further, the occurrence of processing unevenness can be prevented. When the upper limit of the etching amount is in the above range, the amount of the alkaline aqueous solution used is reduced, which is economically advantageous.

  Examples of the alkali used in the alkaline solution include caustic alkali and alkali metal salts. Specifically, examples of caustic alkali include caustic soda and caustic potash. Examples of the alkali metal salt include alkali metal silicates such as sodium metasilicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate and alumina. Alkali metal aluminates such as potassium acid; alkali metal aldones such as sodium gluconate and potassium gluconate; dibasic sodium phosphate, dibasic potassium phosphate, primary sodium phosphate, primary potassium phosphate, etc. An alkali metal hydrogen phosphate is mentioned. Among these, a caustic alkali solution and a solution containing both a caustic alkali and an alkali metal aluminate are preferable from the viewpoint of high etching rate and low cost. In particular, an aqueous solution of caustic soda is preferable.

In the first alkali etching treatment, the concentration of the alkaline solution is preferably 30 g / L or more, more preferably 300 g / L or more, and preferably 500 g / L or less, 450 g / L. The following is more preferable.
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 50 g / L or more, and preferably 200 g / L or less, more preferably 150 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

In the first alkali etching treatment, the temperature of the alkali solution is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, and preferably 80 ° C. or lower, and 75 ° C. or lower. Is more preferable.
In the first alkaline etching treatment, the treatment time is preferably 1 second or longer, more preferably 2 seconds or longer, more preferably 30 seconds or shorter, and more preferably 15 seconds or shorter. preferable.

When the aluminum alloy plate is continuously etched, the aluminum ion concentration in the alkaline solution increases and the etching amount of the aluminum alloy plate varies. Therefore, the composition management of the etching solution is preferably performed as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature corresponding to the matrix of caustic soda concentration and aluminum ion concentration is prepared in advance, and the conductivity and specific gravity are prepared. The liquid composition is measured according to the temperature and temperature, or the electrical conductivity, the ultrasonic wave propagation speed, and the temperature, and caustic soda and water are added so that the control target value of the liquid composition is reached. Then, the amount of the etching solution increased by adding caustic soda and water is overflowed from the circulation tank, thereby keeping the amount of the solution constant. As caustic soda to be added, 40 to 60% by mass for industrial use can be used.
As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the specific gravity meter, a differential pressure type is preferably used.

  Examples of the method of bringing the aluminum alloy plate into contact with the alkaline solution include, for example, a method of passing the aluminum alloy plate through a tank containing an alkaline solution, a method of immersing the aluminum alloy plate in a tank containing an alkaline solution, and an alkali. The method of spraying a solution on the surface of an aluminum alloy plate is mentioned.

  Among these, a method of spraying an alkaline solution onto the surface of the aluminum alloy plate is preferable. Specifically, a method of spraying an etching solution in an amount of 10 to 100 L / min per spray tube from a spray tube having φ2 to 5 mm holes at a pitch of 10 to 50 mm is preferable. It is preferable to provide a plurality of spray tubes.

After the alkali etching process is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing process for 1 to 10 seconds and then drain the liquid with a nip roller.
The water washing treatment is preferably carried out using an apparatus for washing with a free-falling curtain-like liquid film, and further using a spray tube.

The apparatus for washing with a free-fall curtain liquid film is a water storage tank for storing water, a water supply pipe for supplying water to the water storage tank, and a free-fall curtain liquid film from the water storage tank to the aluminum alloy plate. And a rectifying unit.
In this apparatus, water is supplied to the water supply tank from the water supply cylinder, and when the water overflows from the water supply tank, the water is rectified by the rectifying unit, and a free-falling curtain-like liquid film is supplied to the aluminum alloy plate. When this apparatus is used, the liquid amount is preferably 10 to 100 L / min. Moreover, it is preferable that the distance L in which water exists as a free fall curtain-like liquid film between a rectification | straightening part and aluminum is 20-50 mm. Moreover, it is preferable that the angle (alpha) of an aluminum alloy plate is 30-80 degrees with respect to a horizontal direction.

  If an apparatus for performing water washing treatment with a free-fall curtain-like liquid film is used, the aluminum alloy plate can be uniformly washed with water, so that the uniformity of the treatment performed before the water washing treatment can be improved. As a specific apparatus for washing with a free-fall curtain-like liquid film, for example, an apparatus described in JP-A-2003-96584 is preferably exemplified.

  Moreover, as a spray tube used for the water washing process, for example, a spray tube having a plurality of spray tips spreading in a fan shape in the width direction of the aluminum alloy plate can be used. The distance between spray tips is preferably 20 to 100 mm, and the amount of liquid per spray tip is preferably 0.5 to 20 L / min. It is preferable to use a plurality of spray tubes.

<First desmut treatment>
After the first alkali etching treatment, it is preferable to perform pickling (first desmutting treatment) in order to remove dirt (smut) remaining on the surface. The desmut treatment is performed by bringing the aluminum alloy plate into contact with an acidic solution.

Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid.
In the first desmutting process performed after the first alkali etching process, when nitric acid electrolysis is subsequently performed as the electrolytic surface roughening process (first electrolytic surface roughening process), the electrolytic solution used for nitric acid electrolysis It is preferable to use an overflow waste liquid.

In the composition management of the desmut treatment liquid, a method of managing by conductivity and temperature, a method of managing by conductivity, specific gravity and temperature, and a conductivity and superconductivity corresponding to a matrix of acidic solution concentration and aluminum ion concentration. Either of the methods managed by the propagation speed of sound waves and temperature can be selected and used.
In the first desmutting treatment, it is preferable to use an acidic solution containing 1 to 400 g / L acid and 0.1 to 5 g / L aluminum ions.

  The temperature of the acidic solution is preferably 20 ° C. or more, more preferably 30 ° C. or more, and preferably 70 ° C. or less, more preferably 60 ° C. or less.

  In the first desmutting treatment, the treatment time is preferably 1 second or longer, more preferably 4 seconds or longer, and preferably 60 seconds or shorter, more preferably 40 seconds or shorter. .

Examples of the method of bringing an aluminum alloy plate into contact with an acidic solution include a method of passing an aluminum alloy plate through a tank containing an acidic solution, a method of immersing an aluminum alloy plate in a tank containing an acidic solution, and an acidic solution. The method of spraying a solution on the surface of an aluminum alloy plate is mentioned.
Among these, a method in which an acidic solution is sprayed on the surface of the aluminum alloy plate is preferable. Specifically, a method of spraying an etching solution in an amount of 10 to 100 L / min per spray tube from a spray tube having holes of φ2 to 5 mm at a pitch of 10 to 50 mm is preferable. It is preferable to provide a plurality of spray tubes.

After the desmutting process is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing process for 1 to 10 seconds, and then drain the liquid with a nip roller.
The water washing treatment is the same as the water washing treatment after the alkali etching treatment. However, the amount of liquid per spray tip is preferably 1 to 20 L / min.
In the first desmutting process, when using the overflow waste liquid of the electrolyte used for the subsequent nitric acid electrolysis as the desmutting process liquid, the draining and rinsing processes with the nip roller are not performed after the desmutting process. It is preferable to handle the aluminum alloy plate until the nitric acid electrolysis step while spraying a desmut treatment liquid as necessary so that the surface does not dry.

<First electrolytic surface roughening treatment>
The first electrolytic surface roughening treatment is an electrolytic surface roughening treatment in an aqueous solution containing nitric acid or hydrochloric acid.
In the present invention, the first electrolytic surface roughening treatment is preferably a treatment using a trapezoidal waveform alternating current in an electrolytic solution containing nitric acid because the latitude of the electrolytic surface roughened surface is increased. It is preferable to use a sinusoidal alternating current in the electrolyte solution containing slag for the reason that it is easy to control the surface shape of the electrolytically roughened surface.
The average roughness R _a of the aluminum alloy plate surface of the first electrolytic graining treatment is preferably 0.2 to 1.0 [mu] m.

(Electrolytic roughening treatment in aqueous solution containing nitric acid (nitric acid electrolysis))
A suitable uneven structure can be formed on the surface of the aluminum alloy plate by nitric acid electrolysis. In the present invention, when the aluminum alloy plate contains a relatively large amount of Cu, a relatively large and uniform recess is formed in nitric acid electrolysis. As a result, the lithographic printing plate using the lithographic printing plate support of the present invention has excellent printing durability.

An aqueous solution containing nitric acid can be used for an electrochemical surface roughening treatment using ordinary direct current or alternating current, and an aqueous solution of nitric acid having a concentration of 1 to 100 g / L, aluminum nitrate, sodium nitrate, ammonium nitrate, etc. At least one of the nitrate compounds having the nitrate ion can be added and used in the range from 1 g / L to saturation.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the aqueous solution containing nitric acid. Hypochlorous acid or hydrogen peroxide may be added at 1 to 100 g / L.
Specifically, a solution prepared by dissolving aluminum nitrate in an aqueous nitric acid solution having a nitric acid concentration of 5 to 15 g / L and adjusting the aluminum ion concentration to 3 to 7 g / L is preferable.

  The temperature of the aqueous solution containing nitric acid is preferably 20 ° C. or higher, and preferably 55 ° C. or lower.

  Pits having an average opening diameter of 1 to 10 μm can be formed by nitric acid electrolysis. However, when the amount of electricity is relatively large, the electrolytic reaction is concentrated, and honeycomb pits exceeding 10 μm are also generated.

In order to obtain such a grain, the total amount of electricity furnished to anode reaction on the aluminum alloy plate up until the electrolysis reaction is completed is preferably at 150C / dm ² or more, 170C / dm ² or more more preferably is, but preferably not 600C / dm ² or less, more preferably 500C / dm ² or less.
In this case, the current density is preferably 5 A / dm ² or more, more preferably 20 to 100 A / dm ² in terms of current peak value.

(Electrolytic roughening treatment in aqueous solution containing hydrochloric acid (hydrochloric acid electrolysis))
As the aqueous solution containing hydrochloric acid, those used for electrochemical surface roughening treatment using ordinary direct current or alternating current can be used. One or more of hydrochloric acid or nitric acid compounds having nitrate ions such as sodium nitrate and ammonium nitrate, and hydrochloric acid ions such as aluminum chloride, sodium chloride and ammonium chloride can be added to 1 g / L to saturation.
Moreover, the metal contained in aluminum alloys, such as iron, copper, manganese, nickel, titanium, magnesium, a silica, may melt | dissolve in the aqueous solution containing hydrochloric acid. Hypochlorous acid or hydrogen peroxide may be added at 1 to 100 g / L. Furthermore, the above-mentioned compound which forms a complex with copper can also be added at a rate of 1 to 200 g / L. Moreover, sulfuric acid can also be added at a rate of 1 to 100 g / L.

Furthermore, the aqueous solution containing hydrochloric acid has an aluminum ion concentration of 3 to 7 g / L by adding an aluminum salt (aluminum chloride, AlCl ₃ .6H ₂ O) to an aqueous solution containing 2 to 10 g / L of hydrochloric acid, preferably Particularly preferred is an aqueous solution of 4 to 6 g / L.
When electrolytic surface roughening treatment is performed using such an aqueous hydrochloric acid solution, the surface roughened electrolytic surface becomes more uniform, and even if a low purity aluminum alloy plate is used, a high purity aluminum alloy plate is used. Even in this case, processing unevenness does not occur, and it is possible to achieve both excellent printing durability and stain resistance when using a planographic printing plate.

  The temperature of the aqueous solution containing hydrochloric acid is preferably 20 ° C or higher, more preferably 30 ° C or higher, more preferably 55 ° C or lower, and even more preferably 50 ° C or lower.

  As the additive, apparatus, power source, current density, flow rate, and temperature to the aqueous solution containing hydrochloric acid, those used for known electrochemical surface roughening can be used. AC or DC is used as the power source used for electrochemical roughening, but AC is particularly preferable.

Since hydrochloric acid itself has a strong ability to dissolve aluminum, it is possible to form fine irregularities on the surface by applying a slight current. The fine irregularities have an average opening diameter (pit diameter) of 0.01 to 1.5 μm and are uniformly generated on the entire surface of the aluminum alloy plate.
Further, when the amount of electricity is increased (the total amount of electricity (anode reaction) is 150 to 2000 C / dm ² ), the average opening diameter is 1 to 30 μm having pits with an average opening diameter of 0.01 to 0.4 μm on the surface. A pit is generated. In order to obtain such a grain, the total amount of electricity involved in the anode reaction of the aluminum alloy plate at the time when the electrolytic reaction is completed is preferably 10 C / dm ² or more, and more preferably 50 C / dm ² or more. Is more preferable, and more preferably 100 C / dm ² or more. But preferably not more 2000C / dm ² or less, more preferably 600C / dm ² or less.

In hydrochloric acid electrolysis, the current density is preferably 5 A / dm ² or more, more preferably 20 to 100 A / dm ² in terms of the peak current value.

  When the aluminum alloy plate is subjected to hydrochloric acid electrolysis with the above-mentioned large electric quantity, large waviness and fine irregularities can be formed at the same time, and by making the large waviness more uniform by the second alkali etching process described later, the stain resistance is improved. Can be improved.

  The first electrolytic surface roughening treatment can be performed according to, for example, the electrochemical grain method (electrolytic grain method) described in Japanese Patent Publication No. 48-28123 and British Patent No. 896,563. This electrolytic grain method uses a sinusoidal alternating current, but it may be performed using a special waveform as described in JP-A-52-58602. Further, the waveform described in JP-A-3-79799 can also be used. JP-A-55-158298, JP-A-56-28898, JP-A-52-58602, JP-A-52-152302, JP-A-54-85802, JP-A-60-190392, JP-A-58-120531, JP-A-63-176187, JP-A-1-5889, JP-A-1-280590, JP-A-1-118489, JP-A-1-148592, and JP-A-1-17896. JP-A-1-188315, JP-A-1-1549797, JP-A-2-235794, JP-A-3-260100, JP-A-3-253600, JP-A-4-72079, JP-A-4-72098, The methods described in JP-A-3-267400 and JP-A-1-141094 can also be applied. In addition to the above, it is also possible to perform electrolysis using an alternating current having a special frequency that has been proposed as a method of manufacturing an electrolytic capacitor. For example, it is described in US Pat. Nos. 4,276,129 and 4,676,879.

Various electrolyzers and power sources have been proposed, including US Pat. No. 4,203,637, JP-A-56-123400, JP-A-57-59770, JP-A-53-12738, JP 53-32821, JP 53-32222, JP 53-32823, JP 55-122896, JP 55-13284, JP 62-127500, JP Those described in JP-A-1-52100, JP-A-1-52098, JP-A-60-67700, JP-A-1-230800, JP-A-3-257199 and the like can be used.
Further, JP-A-52-58602, JP-A-52-152302, JP-A-53-12738, JP-A-53-12739, JP-A-53-32821, JP-A-53-32822, JP 53-32833, JP 53-32824, JP 53-32825, JP 54-85802, JP 55-122896, JP 55-13284, JP 48-28123, JP-B-51-7081, JP-A-52-13338, JP-A-52-133840, JP-A-52-133844, JP-A-52-133845, JP-A-53-149135 And those described in JP-A No. 54-146234 and the like can also be used.

As the aluminum alloy plate is continuously subjected to electrolytic surface roughening, the aluminum ion concentration in the alkaline solution increases, and the shape of the irregularities of the aluminum alloy plate formed by the first electrolytic surface roughening treatment varies. To do. Therefore, the composition management of the nitric acid electrolytic solution or hydrochloric acid electrolytic solution is preferably performed as follows.
That is, a matrix of conductivity, specific gravity, and temperature, or a matrix of conductivity, ultrasonic propagation velocity, and temperature corresponding to a matrix of nitric acid concentration or hydrochloric acid concentration and aluminum ion concentration is prepared in advance. The liquid composition is measured by the degree, specific gravity and temperature, or the electric conductivity, the ultrasonic wave propagation speed and the temperature, and nitric acid or hydrochloric acid and water are added so as to reach the control target value of the liquid composition. Then, the electrolytic solution increased by adding nitric acid or hydrochloric acid and water is overflowed from the circulation tank, so that the amount of the electrolytic solution is kept constant. As nitric acid to be added, 30 to 70% by mass of industrial grade can be used. As hydrochloric acid to add, the industrial thing of 30-40 mass% can be used.

As the conductivity meter and the specific gravity meter, it is preferable to use those that are temperature-compensated. As the specific gravity meter, a differential pressure type is preferably used.
Samples taken from the electrolyte for use in measuring the liquid composition are used for measurement after being controlled at a constant temperature (eg, 40 ± 0.5 ° C.) using a heat exchanger different from the electrolyte. However, it is preferable in that the accuracy of measurement is increased.

The AC power supply wave used for the electrochemical surface roughening treatment is not particularly limited, and a sine wave (sin wave, sine wave), a rectangular wave, a trapezoidal wave, a triangular wave, or the like is used. Waves are preferred and trapezoidal waves are particularly preferred. In the case of the first hydrochloric acid electrolysis, a sine wave is particularly preferable in that pits having an average diameter of 1 μm or more are easily generated. The sine wave refers to that shown in FIG.
A trapezoidal wave means what was shown in FIG. In this trapezoidal wave, the time (TP) until the current reaches a peak from zero is preferably 0.5 to 3 msec. When TP exceeds 3 msec, especially when an aqueous solution containing nitric acid is used, it becomes susceptible to the influence of trace components in the electrolytic solution typified by ammonium ions and the like that spontaneously increase by electrolytic treatment, and uniform graining. Is difficult to be performed. As a result, the stain resistance tends to decrease when a lithographic printing plate is obtained.

An AC duty ratio of 1: 2 to 2: 1 can be used. However, as described in Japanese Patent Laid-Open No. 5-195300, the duty ratio is used in an indirect power feeding method in which no conductor roll is used for aluminum. Is preferably 1: 1.
An AC frequency of 0.1 to 120 Hz can be used, but 50 to 70 Hz is preferable in terms of equipment. If it is lower than 50 Hz, the carbon electrode of the main electrode is likely to be dissolved, and if it is higher than 70 Hz, it is likely to be affected by the inductance component on the power supply circuit and the power supply cost is increased.

FIG. 2 is a side view showing an example of a radial type cell used for electrochemical roughening treatment using alternating current in the method for producing a lithographic printing plate support of the present invention.
One or more AC power supplies can be connected to the electrolytic cell. For the purpose of controlling the current ratio between the alternating current anode and cathode applied to the aluminum alloy plate facing the main electrode, uniform graining, and dissolving the carbon of the main electrode are shown in FIG. Thus, it is preferable to install an auxiliary anode and divert part of the alternating current. In FIG. 2, 11 is an aluminum alloy plate, 12 is a radial drum roller, 13a and 13b are main poles, 14 is an electrolytic treatment liquid, 15 is an electrolytic solution supply port, and 16 is a slit. Yes, 17 is an electrolyte passage, 18 is an auxiliary anode, 19a and 19b are thyristors, 20 is an AC power source, 40 is a main electrolytic cell, and 50 is an auxiliary anode cell. An anode acting on the aluminum alloy plate facing the main electrode by diverting a part of the current value as a direct current to an auxiliary anode provided in a tank separate from the two main electrodes via a rectifying element or a switching element It is possible to control the ratio between the current value for the reaction and the current value for the cathode reaction. On the aluminum alloy plate facing the main electrode, the ratio of the amount of electricity involved in the anodic reaction and the cathodic reaction (the amount of electricity at the time of cathode / the amount of electricity at the time of anode) is preferably 0.3 to 0.95.

  As the electrolytic cell, electrolytic cells used for known surface treatments such as a vertical type, a flat type, and a radial type can be used, but a radial type electrolytic cell as described in JP-A-5-195300 is particularly preferable. . The electrolytic solution passing through the electrolytic cell may be parallel to the traveling direction of the aluminum web or may be a counter.

  In addition, in the electrochemical surface roughening treatment using direct current, an electrolytic solution used for the normal electrochemical surface roughening treatment using direct current can be used. Specifically, the same electrolyte solution used for the electrochemical surface roughening treatment using the alternating current can be used.

The DC power source wave used for the electrochemical surface roughening treatment is not particularly limited as long as the current does not change in polarity. Smoothed continuous direct current is preferred.
The electrochemical surface roughening treatment using direct current can be performed by any of a batch method, a semi-continuous method and a continuous method, but is preferably performed by a continuous method.

  The apparatus used for the electrochemical surface roughening treatment using direct current applies a direct current voltage between anodes and cathodes arranged alternately, and an aluminum alloy plate is spaced from the anode and cathode. If it can be passed, it will not be specifically limited.

An electrode is not specifically limited, The conventionally well-known electrode used for an electrochemical roughening process can be used.
As the anode, for example, a valve metal such as titanium, tantalum, or niobium is plated or clad with a platinum group metal; the valve metal is coated with a platinum group metal oxide or sintered. Aluminium; stainless steel. Among these, a valve metal obtained by cladding platinum is preferable. The life of the anode can be further extended by a method such as passing water through the electrode to cool it.
As the cathode, for example, a metal that does not dissolve when the electrode potential is negative can be selected and used from the Boolean Bay diagram. Among these, carbon is preferable.

  The arrangement of the electrodes can be appropriately selected according to the wave structure. In addition, by changing the length of the aluminum alloy plate in the traveling direction between the anode and the cathode, changing the passage speed of the aluminum alloy plate, changing the flow rate of the electrolyte, the liquid temperature, the liquid composition, the current density, etc. The structure can be adjusted. In addition, in the case of using an apparatus in which the anode tank and the cathode tank are separated from each other, the electrolysis conditions of each treatment tank can be changed.

After the first electrolytic surface roughening treatment is completed, it is preferable to drain the liquid with a nip roller, and further perform the water washing treatment for 1 to 10 seconds and then drain the liquid with a nip roller.
The washing treatment is preferably carried out using a spray tube. As a spray tube used for the water washing treatment, for example, a spray tube having a plurality of spray tips in the width direction of the aluminum alloy plate in which spray water spreads in a fan shape can be used. The interval between spray tips is preferably 20 to 100 mm, and the amount of liquid per spray tip is preferably 1 to 20 L / min. It is preferable to use a plurality of spray tubes.

<Second alkali etching treatment>
The second alkaline etching process performed between the first electrolytic surface roughening process and the second electrolytic surface roughening process includes dissolving the smut generated in the first electrolytic surface roughening process, and first electrolytic roughening process. This is performed for the purpose of dissolving the edge portion of the pit formed by the surface treatment.
As a result, the edge portion of the large pit formed by the first electrolytic surface-roughening treatment is melted and the surface becomes smooth, and the ink is not easily caught on the edge portion, so that a lithographic printing plate having excellent stain resistance is obtained. be able to.
Since the second alkali etching process is basically the same as the first alkali etching process, only different points will be described below.

In the second alkali etching treatment, the etching amount is preferably at 0.05 g / m ² or more, more preferably 0.1 g / m ² or more, and it is at 4g / m ² or less Preferably, it is 3.5 g / m ² or less. When the etching amount is 0.05 g / m ² or more, in the non-image portion of the lithographic printing plate, the edge portion of the pit generated by the first electrolytic surface-roughening treatment becomes smooth and the ink is less likely to get caught. Excellent in properties. On the other hand, when the etching amount is 4 g / m ² or less, the unevenness generated by the first electrolytic surface roughening treatment becomes large, and thus the printing durability is excellent.

In the second alkali etching treatment, the concentration of the alkaline solution is preferably 30 g / L or more, more preferably 300 g / L or more, and preferably 500 g / L or less, 450 g / L. The following is more preferable.
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 50 g / L or more, and preferably 200 g / L or less, more preferably 150 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

<Second desmut treatment>
After the second alkali etching treatment, it is preferable to perform pickling (second desmut treatment) in order to remove dirt (smut) remaining on the surface. The second desmut process can be performed in the same manner as the first desmut process.

In the second desmut treatment, nitric acid or sulfuric acid is preferably used.
In the second desmutting treatment, it is preferable to use an acidic solution containing 1 to 400 g / L acid and 0.1 to 8 g / L aluminum ions.
When using sulfuric acid, specifically, use a solution prepared by dissolving aluminum sulfate in a sulfuric acid aqueous solution having a sulfuric acid concentration of 100 to 350 g / L so that the aluminum ion concentration becomes 0.1 to 5 g / L. Can do. Moreover, the overflow waste liquid of the electrolyte solution used for the anodizing process mentioned later can also be used.

In the second desmut treatment, the treatment time is preferably 1 second or longer, more preferably 4 seconds or longer, and preferably 60 seconds or shorter, more preferably 20 seconds or shorter. .
In the second desmut treatment, the temperature of the acid aqueous solution is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, and preferably 70 ° C. or lower, and preferably 60 ° C. or lower. More preferred.

<Second electrolytic surface roughening treatment (second hydrochloric acid electrolysis)>
The second electrolytic surface roughening treatment is an electrochemical surface roughening treatment using alternating current or direct current in an aqueous solution containing hydrochloric acid.
In the present invention, only the first electrolytic surface roughening treatment described above may be used, but by combining this second electrolytic surface roughening treatment, a more complicated uneven structure can be formed on the surface of the aluminum alloy plate, As a result, the printing durability can be improved.

The second electrolytic surface roughening treatment is basically the same as the hydrochloric acid electrolysis described in the first electrolytic surface roughening treatment.
The total amount of electricity that the aluminum alloy plate takes part in the anodic reaction by electrochemical surface roughening in an aqueous solution containing hydrochloric acid in the second electrolytic surface roughening treatment is the time when the electrochemical surface roughening treatment is completed. in may be selected from the range of 10~200C / dm ^2, to first electrolytic graining increase destroying not formed was roughened by treatment is preferably ^{10~100C / dm 2, 50~80C / dm} 2 is Particularly preferred.

<First Alkaline Etching Treatment-First Electrolytic Roughening Treatment (Nitric Acid Electrolysis) -Second Alkaline Etching Treatment-Second Electrolytic Roughening Treatment (Second Hydrochloric Acid Electrolysis)>
When performing the above treatment in combination, nitric acid electrolysis in which the total amount of electricity in the anode reaction is 65 to 500 C / dm ² in an electrolytic solution containing nitric acid, and alkaline etching in which the dissolution amount is 0.1 g / m ² or more. Treatment, second hydrochloric acid electrolysis in which the total amount of electricity in the anodic reaction is 25 to 100 C / dm ² in an electrolytic solution containing hydrochloric acid, and alkaline etching treatment in which the dissolution amount is 0.03 g / m ² or more. It is preferable to apply in order.
By roughening with this combination, a lithographic printing plate support capable of obtaining a lithographic printing plate having better stain resistance and printing durability can be obtained.

<Third alkali etching treatment>
The third alkali etching process performed after the second electrolytic surface roughening process involves dissolving the smut generated by the second electrolytic surface roughening process, and the edge of the pit formed by the second electrolytic surface roughening process. This is done for the purpose of dissolving the part. Since the third alkali etching process is basically the same as the first alkali etching process, only different points will be described below.

In the third alkali etching treatment, the etching amount is preferably at 0.05 g / m ² or more, more preferably 0.1 g / m ² or more, is 0.3 g / m ² or less Of 0.25 g / m ² or less is more preferable. When the etching amount is 0.05 g / m ² or more, the edge portion of the pit generated by the second hydrochloric acid electrolysis becomes smooth in the non-image portion of the lithographic printing plate, and the ink is difficult to catch, so that the stain resistance is excellent. . On the other hand, when the etching amount is 0.3 g / m ² or less, the unevenness generated by the first electrolytic surface roughening treatment and the second electrolytic surface roughening treatment becomes large, and thus the printing durability is excellent.

In the third alkali etching treatment, the concentration of the alkali solution is preferably 30 g / L or more, and in order not to make the unevenness generated by the hydrochloric acid alternating current electrolysis in the previous stage too small, the concentration is 100 g / L or less. It is preferable that it is 70 g / L or less.
The alkaline solution preferably contains aluminum ions. The aluminum ion concentration is preferably 1 g / L or more, more preferably 3 g / L or more, preferably 50 g / L or less, more preferably 8 g / L or less. Such an alkaline solution can be prepared using, for example, water, a 48 mass% sodium hydroxide aqueous solution, and sodium aluminate.

In the third alkali etching treatment, the temperature of the alkaline solution is preferably 25 ° C or higher, more preferably 30 ° C or higher, and preferably 60 ° C or lower, and 50 ° C or lower. Is more preferable.
In the third alkali etching treatment, the treatment time is preferably 1 second or longer, more preferably 2 seconds or longer, more preferably 30 seconds or shorter, and more preferably 10 seconds or shorter. preferable.

<Third desmut treatment>
After the third alkali etching treatment, pickling (third desmutting treatment) is preferably performed to remove dirt (smut) remaining on the surface. Since the third desmut process is basically the same as the first desmut process, only the differences will be described below.
In the third desmutting treatment, it is preferable to use an acidic solution containing 5-400 g / L acid and 0.5-8 g / L aluminum ions. When sulfuric acid is used, specifically, a solution prepared by dissolving aluminum sulfate in a sulfuric acid aqueous solution having a sulfuric acid concentration of 100 to 350 g / L to adjust the aluminum ion concentration to 1 to 5 g / L is preferable.

In the third desmut treatment, the treatment time is preferably 1 second or longer, more preferably 4 seconds or longer, and preferably 60 seconds or shorter, more preferably 15 seconds or shorter. .
In the third desmut process, when the same type of liquid as the electrolyte used in the subsequent anodizing process is used as the desmut process liquid, the draining with a nip roller and the water washing process can be omitted after the desmut process.

<Anodizing treatment>
It is preferable to anodize the aluminum alloy plate treated as described above.
The anodizing treatment can be performed by a method conventionally used in this field. In this case, for example, in a solution having a sulfuric acid concentration of 50 to 300 g / L and an aluminum concentration of 5% by mass or less, an anodized film can be formed by energizing an aluminum alloy plate as an anode. As a solution used for the anodizing treatment, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid and the like can be used alone or in combination of two or more.

  Under the present circumstances, the component normally contained at least in an aluminum alloy plate, an electrode, tap water, groundwater, etc. may be contained in electrolyte solution. Furthermore, the second and third components may be added. Examples of the second and third components herein include metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn; Cation such as ammonium ion; anion such as nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc., 0 to 10,000 ppm It may be contained at a concentration of about.

The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. ˜60 A / dm ² , voltage 1 to 100 V, and electrolysis time 15 seconds to 50 minutes are appropriate and adjusted so as to obtain a desired anodic oxide film amount.

  Further, JP-A-54-81133, JP-A-57-47894, JP-A-57-51289, JP-A-57-51290, JP-A-57-54300, JP-A-57-136596, JP-A-58-107498, JP-A-60-200366, JP-A-62-136696, JP-A-63-176494, JP-A-4-17697, JP-A-4-280997, JP-A-6-280997 The methods described in JP-A-207299, JP-A-5-24377, JP-A-5-32083, JP-A-5-125597, JP-A-5-195291 and the like can also be used.

  Of these, as described in JP-A-54-12853 and JP-A-48-45303, it is preferable to use a sulfuric acid solution as the electrolytic solution. The sulfuric acid concentration in the electrolytic solution is preferably 10 to 300 g / L (1 to 30% by mass), more preferably 50 to 200 g / L (5 to 20% by mass), and the aluminum ion concentration. Is preferably 1 to 25 g / L (0.1 to 2.5% by mass), more preferably 2 to 10 g / L (0.2 to 1% by mass). Such an electrolytic solution can be prepared, for example, by adding aluminum sulfate or the like to dilute sulfuric acid having a sulfuric acid concentration of 50 to 200 g / L.

  The composition management of the electrolyte is conducted using the same method as in the case of nitric acid electrolysis described above, and the conductivity, specific gravity and temperature, or conductivity and ultrasonic wave propagation corresponding to the matrix of sulfuric acid concentration and aluminum ion concentration. It is preferable to control by speed and temperature.

  The liquid temperature of the electrolytic solution is preferably 25 to 55 ° C, more preferably 30 to 50.

When anodizing is performed in an electrolytic solution containing sulfuric acid, direct current may be applied between the aluminum alloy plate and the counter electrode, or alternating current may be applied.
When a direct current is applied to the aluminum alloy plate, the current density is preferably from 1 to 60 A / dm ^2, and more preferably 5 to 40 A / dm ^2.
In the case of continuous anodizing treatment, at the beginning of anodizing treatment, so as not to cause so-called "burn" (part where the film becomes thicker than the surroundings) due to current concentration on a part of the aluminum alloy plate. It is preferable to increase the current density to 30 to 50 A / dm ² or higher as the anodic oxidation process proceeds with a current flowing at a low current density of 5 to 10 A / m ² .
Specifically, it is preferable that the current distribution of the DC power supply is set such that the current of the downstream DC power supply is equal to or greater than the current of the upstream DC power supply. By using such current distribution, so-called burning is less likely to occur, and as a result, high-speed anodization can be performed.
In the case where the anodic oxidation treatment is continuously performed, it is preferable to carry out by a liquid power feeding method in which power is supplied to the aluminum alloy plate through the electrolytic solution.
By performing anodizing treatment under such conditions, a porous film having many pores called micropores can be obtained. Usually, the average pore diameter is about 5 to 50 nm, and the average pore density is 300. ˜800 / μm ² or so.

The amount of the anodized film is preferably 1 to 5 g / m ² . If it is less than 1 g / m ² , the plate tends to be damaged, whereas if it exceeds 5 g / m ² , a large amount of electric power is required for production, which is economically disadvantageous. The amount of the anodized film is more preferably 1.5 to 4 g / m ² . Further, it is preferable that the difference in the amount of the anodized film between the center portion of the aluminum alloy plate and the vicinity of the edge portion is 1 g / m ² or less.

As electrolysis apparatuses used for anodizing treatment, those described in JP-A-48-26638, JP-A-47-18739, JP-B-58-24517, JP-A-2001-11698, etc. Can be used.
Among these, the apparatus shown in FIG. 3 is preferably used. FIG. 3 is a schematic view showing an example of an apparatus for anodizing the surface of an aluminum alloy plate.

  In the anodizing apparatus 410 shown in FIG. 3, in order to energize the aluminum alloy plate 416 via the electrolytic solution, the feeding tank 412 is upstream of the aluminum alloy plate 416 in the traveling direction, and the anodizing tank is downstream. 414 is installed. Aluminum alloy plate 416 is conveyed by pass rollers 422 and 428 as indicated by arrows in FIG. In the power supply tank 412 into which the aluminum alloy plate 416 is first introduced, an anode 420 connected to the positive electrode of the DC power supply 434 is installed, and the aluminum alloy plate 416 serves as a cathode. Therefore, a cathode reaction occurs in the aluminum alloy plate 416.

In the anodizing tank 414 into which the aluminum alloy plate 416 is subsequently introduced, a cathode 430 connected to the negative electrode of the DC power source 434 is installed, and the aluminum alloy plate 416 serves as an anode. Therefore, an anodic reaction occurs in the aluminum alloy plate 416, and an anodized film is formed on the surface of the aluminum alloy plate 416.
The distance between the aluminum alloy plate 416 and the cathode 430 is preferably 50 to 200 mm. Aluminum is used as the cathode 430. The cathode 430 is not an electrode having a large area but an electrode divided into a plurality of pieces in the traveling direction of the aluminum alloy plate 416 so that the hydrogen gas generated by the anode reaction can easily escape from the system. preferable.

  Between the power supply tank 412 and the anodizing tank 414, it is preferable to provide a tank called an intermediate tank 413 that does not accumulate an electrolyte as shown in FIG. By providing the intermediate tank 413, it is possible to prevent the current from bypassing the anode 420 to the cathode 430 without passing through the aluminum alloy plate 416. It is preferable to reduce the bypass current as much as possible by installing a nip roller 424 in the intermediate tank 413 to drain the liquid. The electrolyte discharged by draining is discharged out of the anodizing apparatus 410 from the drain port 442.

  The electrolyte solution 418 stored in the power supply tank 412 has a higher temperature and / or higher concentration than the electrolyte solution 426 stored in the anodizing tank 414 in order to reduce voltage loss. In addition, the composition, temperature, and the like of the electrolytic solutions 418 and 426 are determined from the formation efficiency of the anodized film, the micropore shape of the anodized film, the hardness of the anodized film, the voltage, the cost of the electrolytic solution, and the like.

  Electrolyte is ejected from the liquid supply nozzles 436 and 438 and supplied to the power supply tank 412 and the anodizing treatment tank 414. For the purpose of making the distribution of the electrolyte constant and preventing local current concentration of the aluminum alloy plate 416 in the anodizing tank 414, the liquid supply nozzles 436 and 438 are provided with slits, and the ejected liquid flow is changed in the width direction. It has a structure that makes it constant.

  In the anodizing bath 414, a shielding plate 440 is provided on the opposite side of the aluminum alloy plate 416 from the anode 430, and current flows on the opposite side of the surface of the aluminum alloy plate 416 where the anodized film is to be formed. Suppresses The distance between the aluminum alloy plate 416 and the shielding plate 440 is preferably 5 to 30 mm. It is preferable to use a plurality of DC power supplies 434 and connect the positive electrode sides in common. Thereby, the current distribution in the anodizing bath 414 can be controlled.

<Sealing treatment>
In this invention, you may perform the sealing process which seals the micropore which exists in an anodic oxide film as needed. The sealing treatment can be performed according to a known method such as boiling water treatment, hot water treatment, steam treatment, sodium silicate treatment, nitrite treatment, ammonium acetate treatment and the like. For example, even if the sealing treatment is carried out by the apparatus and method described in JP-B-56-12518, JP-A-4-4194, JP-A-5-20296, JP-A-5-179482, etc. Good.

<Hydrophilic treatment>
A hydrophilization treatment may be performed after the anodizing treatment or the sealing treatment. Examples of the hydrophilization treatment include treatment with potassium fluorozirconate 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 primer 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 the Group 4 (Group IVA) metal salt include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium 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 of adsorption is preferably about 1.0 to 15.0 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 hydrophilic 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, a sulfo group-containing vinyl polymerizable compound 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.

<Drying>
After obtaining the lithographic printing plate support as described above, it is preferable to dry the surface of the lithographic printing plate support before providing the image recording layer. Drying is preferably performed after the final treatment of the surface treatment, after washing with water and draining with a nip roller.
The drying temperature is preferably 70 ° C or higher, more preferably 80 ° C or higher, preferably 110 ° C or lower, more preferably 100 ° C or lower.
The drying time is preferably 1 second or more, more preferably 2 seconds or more, and preferably 20 seconds or less, more preferably 15 seconds.

<Management of liquid composition>
In the present invention, it is preferable to manage the composition of various processing solutions used for the surface treatment described above by the method described in JP-A-2001-121837. Prepare a large number of treatment liquid samples of various concentrations in advance, measure the ultrasonic wave propagation speed at each of the two liquid temperatures, create a matrix-like data table, It is preferable to measure the propagation speed of the light in real time and control the concentration based on the measurement. In particular, in the desmutting treatment, when an electrolytic solution having a sulfuric acid concentration of 250 g / L or more is used, it is preferable to control the concentration by the method described above.
In addition, it is preferable that each electrolyte solution used for an electrolytic roughening process and an anodic oxidation process is 100 ppm or less of Cu concentration. If the Cu concentration is too high, Cu is deposited on the aluminum alloy plate when the line is stopped, and Cu deposited when the line is operated again may be transferred to a pass roll, which may cause processing unevenness.

[Lithographic printing plate precursor]
The lithographic printing plate support of the present invention can be provided with an image recording layer to form the lithographic printing plate precursor of the present invention. A photosensitive composition is used for the image recording layer.
Examples of the photosensitive composition suitably used in the present invention include a thermal positive photosensitive composition containing an alkali-soluble polymer compound and a photothermal conversion substance (hereinafter, this composition and an image recording layer using the same). ), A thermal negative photosensitive composition containing a curable compound and a photothermal conversion substance (hereinafter also referred to as “thermal negative type”), a photopolymerizable photosensitive composition (hereinafter referred to as “thermal positive type”). , Also referred to as “photopolymer type”), negative photosensitive composition containing diazo resin or photocrosslinking resin (hereinafter also referred to as “conventional negative type”), and positive photosensitive composition containing quinonediazide compound. Product (hereinafter also referred to as "conventional positive type"), photosensitive composition that does not require a special development step (hereinafter referred to as As the referred to as "non-treatment type".), And the like.
As each of the photosensitive composition of thermal positive type, thermal negative type, conventional negative type, and non-processing type, for example, a composition containing various materials described in JP-A-2008-111142 can be used.

<Back coat>
In this way, the backside of the lithographic printing plate precursor of the present invention obtained by providing various image recording layers on the lithographic printing plate support obtained by the present invention, if necessary, is an image in the case of overlapping. In order to prevent the recording layer from being damaged, a coating layer made of an organic polymer compound can be provided.

[Plate making method (lithographic printing plate production method)]
The lithographic printing plate precursor using the lithographic printing plate support obtained by the present invention is made into a lithographic printing plate by various treatment methods according to the image recording layer.
Examples of the active light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of the laser beam include a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a YAG-SHG laser.

After the above exposure, if the image recording layer is any of thermal positive type, thermal negative type, conventional negative type, conventional positive type, and photopolymer type, after exposure, it is developed using a developer to obtain a lithographic printing plate. It is preferable to obtain.
The developer is preferably an alkaline developer, and more preferably an alkaline aqueous solution substantially free of an organic solvent.
Moreover, the developing solution which does not contain alkali metal silicate substantially is also preferable. As a method for developing using a developer substantially not containing an alkali metal silicate, a method described in detail in JP-A-11-109637 can be used.
A developer containing an alkali metal silicate can also be used.

Hereinafter, the present invention will be described in more detail with reference to examples.
[Production of aluminum alloy plate and lithographic printing plate support]
(Examples 1-12, Comparative Examples 1-11)
Aluminum alloy sheets were produced by continuous casting using the aluminum alloy melts (Al-1 to Al-18) having the compositions shown in Table 1 below and subjected to heat treatment (intermediate annealing) under the conditions shown in Table 2 below. .
Specifically, first, continuous casting was performed using a molten aluminum alloy of each composition so that the cast plate thickness was 5.5 mm by twin roll type continuous casting.
Next, the obtained continuous cast plate was cold-rolled to a thickness of 0.9 mm, then subjected to intermediate annealing heat treatment under the conditions shown in Table 2 below, and further cold-rolled again to 0.3 mm. Finished with a thickness of.
Next, flatness was corrected using a tension leveler to produce an aluminum alloy plate. In addition, the composition of the manufactured aluminum alloy plate is the same as the composition of the aluminum alloy molten metal (Al-1 to Al-18) used for each.

(Example 13)
An aluminum alloy plate of Example 13 was manufactured by DC casting without heat treatment using a molten aluminum alloy (Al-5).
Specifically, a slab having a thickness of 500 mm was cast by DC casting using a molten aluminum alloy of Al-5.
Next, both sides of the obtained slab were chamfered by 20 mm and subjected to soaking at 500 to 600 ° C.
Subsequently, it hot-rolled and rolled to thickness 3mm, it was made to recrystallize with rolling processing heat, and cold-rolled and finished to thickness 0.3mm.
Next, flatness was corrected using a tension leveler to produce an aluminum alloy plate. In addition, the composition of the manufactured aluminum alloy plate is the same as the composition of the molten aluminum alloy (Al-5).

  The amount of Si and Fe dissolved in each manufactured aluminum alloy plate and the number of intermetallic compounds per unit area were measured by the following methods. These results are shown in Table 2 below.

(Solution amount of Si and Fe)
The solid solution amount of Si and Fe was measured by a phenol dissolution extraction method.
Specifically, a test piece made of each manufactured aluminum alloy plate was dissolved with hot phenol, and then benzyl alcohol was added.
Subsequently, it filtered using the filter made from a polytetrafluoroethylene, and removed the intermetallic compound residue.
Subsequently, after diluting with benzyl alcohol, Si and Fe contained in the solution were extracted and quantified by standard addition ICP emission spectrometry.

(Number of intermetallic compounds per unit area and average diameter)
First, about the manufactured aluminum alloy plate, what wiped off the oil of the surface with acetone was used as a measurement sample.
Next, using a scanning electron microscope (PC-SEM7401F, manufactured by JEOL Ltd.), a reflected electron image on the surface of the aluminum alloy plate was taken under the conditions of an acceleration voltage of 12.0 kV and a magnification of 2000 times.
Next, five images arbitrarily selected from the obtained reflected electron images were stored in JPEG format, and converted into bmf (bitmap file) format using MS-Paint (manufactured by Microsoft).
This bmf format file is stored in the image analysis software ImageFactory Ver. 3.2 After reading into the Japanese version (Asahi Hitech Co., Ltd.) and performing image analysis, static binarization processing of the image is performed, and the portion corresponding to the white intermetallic compound is counted as a feature value. The particle size distribution was obtained by specifying the equivalent circle diameter (equivalent circle diameter).
From the result of the particle size distribution, the number of intermetallic compounds having an equivalent circle diameter of 0.2 μm or more was calculated. This calculation was performed by rounding the average value of the numbers calculated from each of the five image data (particle size distributions) to the nearest hundred.
Similarly, from the result of the particle size distribution, the average value of the equivalent circle diameters of the intermetallic compounds was calculated as the average diameter.

  Each manufactured aluminum alloy plate was subjected to the following roughening treatment to produce a lithographic printing plate support.

<Roughening treatment I>
As the surface roughening treatment I, the following treatments (a) to (e) were performed. In addition, the water washing process was performed between all the process steps.

(A) Alkaline etching treatment An aqueous solution having a caustic soda concentration of 25% by mass, an aluminum ion concentration of 100 g / L, and a temperature of 60 ° C. was sprayed from a spray tube to each of the manufactured aluminum alloy plates to perform an etching treatment. The etching amount of the surface subjected to the electrochemical roughening treatment after the aluminum alloy plate was 5 g / m ² .
(B) Desmutting treatment Next, a 1% by mass nitric acid aqueous solution having a temperature of 35 ° C. was sprayed from the spray tube for 5 seconds to perform desmutting treatment.
(C) Electrolytic surface roughening treatment Thereafter, an electrolytic solution (liquid temperature 50 ° C.) in which aluminum nitrate is dissolved in a 1% by mass nitric acid aqueous solution to have an aluminum ion concentration of 4.5 g / L is used, and an AC voltage of 60 Hz is used. Then, the electrochemical surface roughening treatment was performed continuously. The AC power supply waveform is the waveform shown in FIG. 1. The time TP until the current value reaches a peak from zero is 0.8 msec, the duty ratio (ta / T, the ratio of the anode reaction time in one cycle) 0.5 Met. A carbon electrode was used as the counter electrode. Ferrite was used for the auxiliary anode. Two electrolytic cells shown in FIG. 2 were used.
In the electrochemical surface roughening treatment, the current density during the anode reaction of the aluminum alloy plate at the peak of alternating current was 60 A / dm ² . The ratio of the total amount of electricity during the anode reaction of the aluminum alloy plate to the total amount of electricity during the cathode reaction was 0.95. The amount of electricity was 190 C / dm ² in terms of the total amount of electricity at the anode of the aluminum alloy plate. 5% of the current flowing from the power source was shunted to the auxiliary anode. The relative speed of the aluminum alloy plate and the electrolytic solution was 1.5 m / sec on average in the electrolytic cell.
(D) Alkaline etching treatment An aqueous solution having a caustic soda concentration of 5% by mass, an aluminum ion concentration of 5 g / L, and a temperature of 35 ° C. was sprayed from a spray tube onto the aluminum alloy plate to carry out an etching treatment. The etching amount of the aluminum alloy plate subjected to the electrochemical surface roughening treatment was 0.1 g / m ² .
(E) Desmut treatment As the aqueous solution, desmut treatment was performed by spraying from a spray tube for 5 seconds using a sulfuric acid concentration of 300 g / L, an aluminum ion concentration of 5 g / L, and a liquid temperature of 35 ° C.

  For each lithographic printing plate support obtained by applying the roughening treatment I, the uniformity of the electrolytically roughened surface and the diameter of the pits were measured by the following methods. The results are shown in Table 3 below.

(Evaluation of uniformity of electrolytic roughened surface)
The surface of each lithographic printing plate support after electrolytic surface roughening treatment was observed with a scanning electron microscope (SEM: JEOL 5500) (magnification 2000 times), and the uniformity of graining was evaluated according to the following criteria. did. O If it is the above evaluation, it can be used practically without a problem.
(Double-circle): A round pit is 90% or more of the whole.
◯: Round pits are 50% or more and less than 90% of the whole.
(Triangle | delta): A round pit is 10% or more and less than 50% of the whole.
X: A round pit is less than 10% of the whole.

(Pit diameter)
The surface of each lithographic printing plate support after the electrolytic surface-roughening treatment was observed with an electron microscope at magnifications of 500 times and 2000 times (both angles were 0 °), and evaluated according to the following criteria. If the evaluation is B or more, it can be used practically without any problem.
A: Pits having average opening diameters of 0.01 to 0.05 μm and 0.05 to 1.5 μm are uniformly formed on the entire surface.
B: Pits having an average opening diameter of 0.01 to 0.05 μm or 0.05 to 1.5 μm are uniformly formed on the entire surface.
C: Pits having an average opening diameter of 0.01 to 0.05 μm are formed at a ratio (area ratio) of 20% or less of the entire surface.
D: Pits having an average opening diameter larger than 1.5 μm are formed at a ratio (area ratio) of 20% or more of the entire surface.

<Roughening treatment II>
As the roughening treatment II, the following treatments (a) to (e) were performed. In addition, the water washing process was performed between all the process steps.

(A) Alkaline etching treatment An aqueous solution having a caustic soda concentration of 25% by mass, an aluminum ion concentration of 100 g / L, and a temperature of 60 ° C. was sprayed from a spray tube to each of the manufactured aluminum alloy plates to perform an etching treatment. The etching amount of the surface subjected to the electrochemical roughening treatment after the aluminum alloy plate was 3 g / m ² .
(B) Desmut treatment Next, a sulfuric acid aqueous solution (concentration: 300 g / L) having a temperature of 35 ° C. was sprayed from the spray tube for 5 seconds to perform desmut treatment.
(C) Electrolytic roughening treatment Thereafter, an electrolytic solution (liquid temperature 35 ° C.) in which aluminum chloride is dissolved in 1% by mass hydrochloric acid aqueous solution to have an aluminum ion concentration of 4.5 g / L is used, and a 60 Hz AC power source is used. Then, electrochemical surface roughening treatment was continuously performed using a flat cell type electrolytic cell. A sine wave was used as the waveform of the AC power supply. In the electrochemical surface roughening treatment, the current density during the anode reaction of the aluminum alloy plate at the peak of alternating current was 30 A / dm ² . The ratio of the amount of electricity during the anode reaction of the aluminum alloy plate to the amount of electricity during the cathode reaction was 0.95. The amount of electricity was 480 C / dm ^{2 as the} total amount of electricity at the time of anode of the aluminum alloy plate. The electrolytic solution was stirred in the electrolytic cell by circulating the solution using a pump.
(D) Alkaline etching treatment An aqueous solution having a caustic soda concentration of 5% by mass, an aluminum ion concentration of 5 g / L, and a temperature of 35 ° C. was sprayed from a spray tube onto the aluminum alloy plate to carry out an etching treatment. The etching amount of the aluminum alloy plate subjected to the electrolytic surface roughening treatment was 0.05 g / m ² .
(E) Desmutting treatment An aqueous solution having a sulfuric acid concentration of 300 g / L, an aluminum ion concentration of 5 g / L, and a liquid temperature of 35 ° C. was sprayed from a spray tube for 5 seconds to perform desmutting treatment.

About each lithographic printing plate support obtained by performing the roughening treatment II, the uniformity of the electrolytically roughened surface was measured by the following method. The results are shown in Table 3 below.
In the electrolytic surface roughening in hydrochloric acid solution performed in the roughening treatment II, there are two large wave pits having an equivalent circle diameter of 5 μm or more and a plateau part where no large wave pits are formed. There is a portion where small shallow pits of 0.5 μm or less are formed on the surface, but it is desirable that a large wave pit having a circle equivalent diameter of 5 μm or more is uniformly formed on the entire surface with a small plateau part. Evaluation was performed based on criteria.

(Evaluation of uniformity of electrolytic roughened surface)
The surface of each lithographic printing plate support after electrolytic surface roughening treatment was observed with a scanning electron microscope (SEM: JEOL 5500) (magnification 2000 times), and the uniformity of graining was evaluated according to the following criteria. did. O If it is the above evaluation, it can be used practically without a problem.
(Double-circle): The plateau part in which the large wave pit is not formed is less than 5% of the whole.
◯: The plateau portion where no large wave pits are formed is 5% or more and less than 10% of the whole.
(Triangle | delta): The plateau part in which the large wave pit is not formed is 10% or more and less than 40% of the whole.
X: The plateau part in which the large wave pit is not formed is 50% or more of the whole.

<Roughening treatment III>
As the roughening treatment III, the following treatments (a) to (k) were performed. In addition, the water washing process was performed between all the process steps.

(A) Mechanical roughening treatment (brush grain method)
Rotating while supplying an aqueous suspension (specific gravity 1.12 g / cm ³ ) of an abrasive (pumice) as a polishing slurry liquid to the surface of the aluminum alloy plate using an apparatus as schematically shown in FIG. The surface was mechanically roughened with a roller nylon brush. In FIG. 5, 1 is an aluminum alloy plate, 2 and 4 are roller brushes, 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers.
Here, the average particle size of the abrasive was 40 μm, and the maximum particle size was 100 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum alloy plate. The rotation direction of the brush was the same as the movement direction of the aluminum alloy plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment Using an aqueous solution having a caustic soda concentration of 26 mass%, an aluminum ion concentration of 6.5 mass%, and a temperature of 70 ° C., an aluminum alloy plate was dissolved by 10 g / m ² . Then, water washing by spraying was performed.

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

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

(E) Alkaline etching treatment An etching treatment by spraying is performed at 60 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass% to dissolve 1.0 g / m ^{2 of the} aluminum alloy plate. The smut component mainly composed of aluminum hydroxide generated when the electrolytic surface roughening treatment was performed using alternating current was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Then, water washing by spraying was performed.

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

(G) Electrolytic surface roughening treatment An electrochemical surface roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform is the waveform shown in FIG. 1. The time TP until the current value reaches a 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 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum alloy plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode.
Then, water washing by spraying was performed.

(H) Alkaline etching treatment Using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass, an etching treatment by spraying is performed at 32 ° C. to dissolve the aluminum alloy plate by 0.5 g / m ^2. The smut component mainly composed of aluminum hydroxide generated when the electrolytic surface roughening treatment was performed using alternating current was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Then, water washing by spraying was performed.

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

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

(K) Hydrophilization treatment Hydrophilic treatment (alkali metal silicate treatment) was performed by immersing in a treatment tank of 1 mass% aqueous solution of sodium silicate No. 3 having a liquid temperature of 20 ° C. for 10 seconds. Then, the water washing by the spray using well water was performed.

About each lithographic printing plate support obtained by performing the roughening treatment III, the uniformity of the electrolytic roughened surface was measured by the method described below. The results are shown in Table 3 below.
When the surface roughening treatment III is performed, a large wave pit of about 5 to 15 μm, a medium wave pit of about 1 to 3 μm, and a small wave pit of 0.5 μm or less are formed on the surface.
Here, whether the small wave and medium wave pits are uniformly formed on the entire surface was evaluated based on the following two criteria.

(Evaluation of uniformity of electrolytic roughened surface)
(1) The surface of each lithographic printing plate support after electrolytic graining treatment was observed with a scanning electron microscope (SEM: JEOL 5500) (magnification 10,000 times), and grained uniformly according to the criteria shown below. Sex was evaluated. O If it is the above evaluation, it can be used practically without a problem.
(Double-circle): The part in which the small wave pit is not formed is less than 3% of the whole.
○: The portion where the wave pits are not formed is 3% or more and less than 10% of the whole.
(Triangle | delta): The part in which the small wave pit is not formed is 10% or more and less than 30% of the whole.
X: The portion where no wavelet pits are formed is 30% or more of the whole.
(2) The surface of each lithographic printing plate support after the electrolytic surface-roughening treatment was observed with a scanning electron microscope (SEM: JEOL 5500) (magnification 2000 times), and grained uniformly according to the criteria shown below. Sex was evaluated. O If it is the above evaluation, it can be used practically without a problem.
A: Medium wave pits are formed in 90% or more of the whole.
A: Medium wave pits are 60% or more and less than 90%.
Δ: Medium wave pits are 30% or more and less than 60% of the whole.
X: Medium wave pits are less than 30% of the whole.

From the results shown in Tables 1 to 3, the following was found.
It was found that Comparative Example 1 using an aluminum alloy plate with a large amount of Fe in solid solution was inferior in uniformity of the roughened surface when the roughening treatments II and III were performed.
On the other hand, it was found that Comparative Examples 2 and 7 using an aluminum alloy plate with a small Si solid solution amount were inferior in uniformity of the roughened surface under any surface roughening conditions.
Moreover, it turned out that the comparative example 3 using the aluminum alloy plate with many solid solution amounts of Fe and few intermetallic compounds is inferior to the uniformity of a roughening process surface in any roughening process conditions.
Further, Comparative Example 4 using an aluminum alloy plate having a high Si content and a high solid solution amount of Si and Fe and having a small amount of intermetallic compounds is the uniformity of the roughened surface under any roughening conditions. Was found to be very inferior.
Moreover, it turned out that the comparative example 5 using the aluminum alloy board with much content of Fe is inferior to the uniformity of the roughening process surface, when the roughening process II is given.
Further, Comparative Example 6 using an aluminum alloy plate having a low Fe content, a solid solution amount of Si, and an intermetallic compound is extremely inferior in the uniformity of the roughened surface under any roughening conditions. I understood that.
Moreover, it turned out that the comparative example 8 using the aluminum alloy board with much content of Si is inferior to the uniformity of a roughening process surface in any roughening process conditions.
Further, Comparative Example 9 using an aluminum alloy plate having a low Si content, a solid solution amount of Si, and an intermetallic compound may have poor uniformity of the roughened surface under any surface roughening conditions. I understood.
Moreover, it turned out that the comparative example 10 using the aluminum alloy board with little content of Fe is inferior to the uniformity of a roughening process surface in any roughening process conditions.
Further, Comparative Example 11 using an aluminum alloy plate with a large amount of Fe in solid solution is an experimental example similar to Example 4 described in Patent Document 7, and when roughening treatment II is performed, a rough surface is obtained. It was found that the uniformity of the chemical treatment surface was inferior.

On the other hand, an aluminum alloy plate in which the content of Si and Fe and the solid solution amount of Si and Fe are in a predetermined range, and the intermetallic compound having an equivalent circle diameter of 0.2 μm or more is 20000 pieces / mm ² or more It was found that Examples 1 to 12 were excellent in the uniformity of the roughened surface under any roughening conditions.
In particular, from the results of Example 12, the same aluminum alloy melt (Al-18) as Comparative Example 11 was used, but the heat treatment conditions of Comparative Example 11 were changed to reduce the solid solution amount of Fe to 100 ppm or less. It was found that the uniformity of the roughened surface when the roughening treatment II was performed can be improved.
On the other hand, in Example 13 using the aluminum alloy plate manufactured by DC casting, the content of Si and Fe and the solid solution amount of Si and Fe are in a predetermined range, but the metal whose equivalent circle diameter is 0.2 μm or more. Since the intermetallic compound was 20000 pieces / mm ² or less, it was found that the uniformity of the electrolytic roughened surface was slightly inferior compared with Example 5 using the same molten aluminum alloy (Al-5).

[Manufacture of lithographic printing plate precursors]
The following thermal positive type image recording layer was provided on each lithographic printing plate support obtained by each surface roughening treatment to obtain a lithographic printing plate precursor. Before providing the image recording layer, the following undercoat layer was provided.

An undercoat solution having the following composition was applied onto a lithographic printing plate support and dried at 80 ° C. for 15 seconds to form a coating film of an undercoat layer. The coating amount of the coating film after drying was 15 mg / m ² .

<Undercoat liquid composition>
・ The following polymer compound 0.3g
・ Methanol 100g
・ Water 1g

Furthermore, a heat-sensitive layer coating solution having the following composition was prepared, and the coating amount after drying the heat-sensitive layer coating solution (heat-sensitive layer coating amount) on a lithographic printing plate support provided with an undercoat layer was 1.8 g / m. ² was applied and dried to form a heat sensitive layer (thermal positive type image recording layer) to obtain a lithographic printing plate precursor.

<Thermosensitive layer coating solution composition>
Novolak resin (m-cresol / p-cresol = 60/40, weight average molecular weight 7,000, containing 0.5% by mass of unreacted cresol) 0.90 g
・ Ethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (molar ratio 35/35/30) 0.10 g
-Cyanine dye A 0.1 g represented by the following structural formula
・ Tetrahydrophthalic anhydride 0.05g
・ 0.002 g of p-toluenesulfonic acid
-Ethyl violet counter ion with 6-hydroxy-β-naphthalenesulfonic acid 0.02 g
・ Fluorosurfactant (Defenser F-780F, manufactured by Dainippon Ink & Chemicals, Inc., solid content: 30% by mass) 0.0045 g (solid content conversion)
・ Fluorine-based surfactant (Defenser F-781F, manufactured by Dainippon Ink & Chemicals, Inc., solid content: 100% by mass) 0.035 g
・ Methyl ethyl ketone 12g

Each obtained lithographic printing plate precursor was imaged using a TrendSetter manufactured by Creo at a drum rotation speed of 150 rpm and a beam intensity of 10 W.
Thereafter, using a PS processor 940H manufactured by Fuji Photo Film Co., Ltd., charged with an alkali developer having the following composition, the solution temperature was maintained at 30 ° C. and development was performed for 20 seconds to obtain a lithographic printing plate.

<Alkali developer composition>
・ D-Sorbit 2.5% by mass
-Sodium hydroxide 0.85 mass%
・ Polyethylene glycol lauryl ether (weight average molecular weight 1,000) 0.5 mass%
・ Water 96.15% by mass

  The resulting lithographic printing plate precursor was subjected to exposure and development treatments, and the printing durability and stain resistance of the lithographic printing plate were evaluated. The results are shown in Table 4.

(Evaluation of stain resistance)
Blanket after printing 10000 sheets of DIC-GEOS (s) red ink on Mitsubishi Diamond F2 printer (Mitsubishi Heavy Industries, Ltd.) using the lithographic printing plate obtained above. Was visually confirmed and evaluated according to the following criteria.
A: The blanket is not dirty B: The blanket is almost dirty C: The blanket is slightly dirty D: The blanket is dirty but within an acceptable range E: The blanket is dirty and the printed matter is clear F: The blanket is very dirty G: The blanket is very dirty

(Evaluation of printing durability)
Printing using Komori Corporation's Lithrone printing machine using DIC-GEOS (N) ink made by Dainippon Ink & Chemicals, Inc., when it is visually recognized that the density of the solid image has started to fade Printing durability was evaluated by the number of sheets.

From the results shown in Table 4, when Examples and Comparative Examples are compared among the roughening treatment conditions, the lithographic printing plate precursors of Examples 1 to 13 are all the lithographic plates obtained in Comparative Examples 1 to 11 It was found that either or both of the stain resistance and the printing durability as a lithographic printing plate were better than those of the printing plate precursor.
For example, when comparing aluminum alloy plates having the same composition, comparison between Example 1 and Comparative Example 1, comparison between Example 5 and Comparative Example 2 and Comparative Example 7, comparison between Example 6 and Comparative Example 3, and implementation From the comparison between Example 12 and Comparative Example 11, it can be seen that either of the examples is superior in stain resistance and printing durability or both in comparison with the corresponding comparative example.
On the other hand, Example 13 using the aluminum alloy plate manufactured by DC casting has a slightly inferior uniformity of the electrolytic roughened surface as compared with Example 5, so that the roughening treatments I and II are performed. It was found that the stain resistance compared with Example 5 was slightly inferior for the case where the above was applied.
For the lithographic printing plate precursors of Examples and Comparative Examples used for evaluation of printing durability and stain resistance, the solid solution amounts of Si and Fe were determined by the method described in paragraph [0149] after removing the image recording layer. When measured, it was found that there was no significant difference from the value measured with the aluminum alloy plate.

DESCRIPTION OF SYMBOLS 1 Aluminum alloy plate 2, 4 Roller-like brush 3 Polishing slurry liquid 5, 6, 7, 8 Support roller 11 Aluminum alloy plate 12 Radial drum roller 13a, 13b Main electrode 14 Electrolytic treatment liquid 15 Electrolytic solution supply port 16 Slit 17 Electrolytic solution Passage 18 Auxiliary anode 19a, 19b Thyristor 20 AC power supply 40 Main electrolytic tank 50 Auxiliary anode tank 410 Anodizing device 412 Feed tank 413 Intermediate tank 414 Anodizing tank 416 Aluminum alloy plate 418, 426 Electrolytic solution 420 Anode 422, 428 Pass roller 424 Nip roller 430 Cathode 434 DC power supply 436, 438 Liquid supply nozzle 440 Shielding plate 442 Drain outlet 610 Anodizing device 612 Power supply tank 614 Electrolytic treatment tank 616 Aluminum alloy plate 618, 626 Electrolytic solution 620 Power supply 622,628 roller 624 nip roller 630 electrolytic electrode 632 tank wall 634 a DC power source

Claims (8)

  It contains 0.03-0.20 mass% Si and 0.11-0.45 mass% Fe, the solid solution amount of Si is 120-600 ppm, and the solid solution amount of Fe is 100 ppm or less. Aluminum alloy plate for lithographic printing plates. On the surface, having an intermetallic compound circle equivalent diameter is 0.2μm or more 20000 / mm ² or more, aluminum alloy strip for lithographic printing plates according to claim 1.   The aluminum alloy plate for lithographic printing plates according to claim 1 or 2, wherein the Cu content is 0.030% by mass or less.   Any one of Claims 1-3 obtained by continuous casting which supplies aluminum alloy molten metal between a pair of cooling rollers via a molten metal supply nozzle, and performs rolling while solidifying the aluminum alloy molten metal with the pair of cooling rollers. An aluminum alloy plate for lithographic printing plates according to any one of the above.   A support for 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 a roughening treatment including an electrochemical roughening treatment.   The lithographic printing plate support according to claim 5, wherein the roughening treatment further includes an alkali etching treatment before the electrochemical roughening treatment.   The lithographic printing plate support according to claim 5 or 6, wherein the roughening treatment further comprises an alkali etching treatment after the electrochemical roughening treatment.   A lithographic printing plate precursor comprising an image recording layer provided on the lithographic printing plate support according to any one of claims 5 to 7.