JPH11240275A - Manufacture of aluminum carrier for lithographic plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a lithography aluminum carrier to manufacture a lithography aluminum carrier stably at low costs, in which there never almost happens the occurrence of treatment unevenness caused by orientation difference of crystal grains so called streaks and image quantity irregularities. SOLUTION: An aluminum plate is subjected by turns to preliminarily electrochemical roughened-surface by the use of AC with a quantity of electricity of 1-300 c/dm<2> in a solution consisting of mainly hydrochloric acid (1). In the next place, chemical etchings is carrier out in acid or an alkalic solution or electrolysis grinding treatmetnis is performed by utilizing the aluminum plate as an anode to dissolve the aluminum plate by 0.01-1.5 g/cm<2> (2), and subsequently, it is electrochemically surface-roughened in use of DC or AC in a solution consisting of mainly of nitric acid (3). Furthermore, chemical etching is executed in acid or an alkalic solution, or hydrolysis grinding therment is implemented by employing the aluminum plate as an anode so as to dissolve the aluminum plate by 0.01-10 g/m<2> , whereby manufacturing a lithography aluminum carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aluminum support used as a support for a lithographic printing plate. In particular, in the present invention, streaks called streaks caused by misorientation of crystal grains and uneven processing called rough surface called uneven surface quality, which are easily generated by the conventional chemical etching method, occur. The present invention relates to a method suitable for easily roughening an aluminum plate.

[0002]

2. Description of the Related Art As a method of roughening an aluminum support for a lithographic printing plate, an AC etching method is generally employed. As a current, a special alternating waveform current such as a normal sine wave AC or a rectangular wave is used. Is used. The surface of the aluminum plate is roughened by alternating current using an appropriate electrode such as graphite as a counter electrode, and is usually performed in a single process, but the pit depth obtained there is generally shallow. , Poor printability. For this reason, various methods have been proposed so as to obtain an aluminum plate suitable as a support for a printing plate having a grain, in which pits having a depth deeper than its diameter are uniformly and densely present. Examples of the method include a surface roughening method using a special electrolytic power source waveform (Japanese Patent Application Laid-Open No. 53-67507), and a ratio of the amount of electricity between an anode and a cathode during electrolytic surface roughening using an alternating current (JP-A-53-67507). 1954-65
607), a power supply waveform (Japanese Patent Application Laid-Open No. 56-25381), and a combination of the amount of current per unit area (Japanese Patent Application Laid-Open No. 56-29699) are known.

On the other hand, as a method of manufacturing an aluminum support, a slab (thickness: 400 to 600 mm, width: 1000 to 2000 m) is melted and held in an aluminum ingot.
m, length 2000-6000 mm), and after passing through a face milling step of cutting the impurity structure portion of the slab surface by a face mill at a rate of 3 to 10 mm, to remove stress inside the slab and homogenize the structure, 480-540 ° C in a soaking furnace,
A soaking process is performed for 6 to 12 hours, followed by hot rolling at 480 to 540 ° C. 5 to hot rolling
After rolling to a thickness of 40 mm, cold rolling is performed to a predetermined thickness at room temperature. After that, annealing is performed to homogenize the structure to homogenize the rolled structure and the like, then cold-rolled to a specified thickness, and straightened to obtain a plate having good flatness. The aluminum support thus produced was used as a support for a lithographic printing plate. As an aluminum support for a lithographic printing plate, it is desired to use a general-purpose aluminum plate or an aluminum plate obtained by omitting intermediate annealing or soaking from the manufacturing process of an aluminum plate from the viewpoint of energy saving and effective use of resources. However, when an aluminum support for a lithographic printing plate was manufactured using the aluminum plate, processing irregularities called streaks and surface quality irregularities were likely to occur. This is said to be because the dissolution rate differs depending on the crystal orientation when the chemical dissolution reaction of aluminum proceeds, and the reaction differs depending on the crystal orientation when the electrochemical pitting reaction proceeds on aluminum. In other words, irregularities formed by the dissolution rate difference in the chemical dissolution reaction appear as streaks and unevenness in surface quality, and differences in pitting reactions (differences in the number of pits and sizes) due to crystal orientations appear as streaks and uneven surface quality. appear.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a method for producing an aluminum support for a lithographic printing plate, which does not cause the above-mentioned streak or uneven surface quality.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that lithographic printing is characterized in that after an aluminum plate is provided with fine irregularities, it is electrochemically roughened in an acidic aqueous solution. By the method of manufacturing an aluminum support for a plate,
The present inventors have found a method for producing an aluminum support for a lithographic printing plate which does not cause a failure called streak or uneven surface quality. That is,
The main aspect of the present invention is that (1) an aluminum plate is sequentially placed in an aqueous solution mainly containing hydrochloric acid by using an alternating current in a range of 1 to 300.
Preliminary electrochemical surface roughening is performed with an amount of electricity of C / dm ² , (2) chemical etching in an acid or alkali aqueous solution, or electrolytic polishing using an aluminum plate as an anode, An aluminum plate is dissolved in an amount of 0.01 to 1.5 g / m ² , (3) electrochemical surface roughening is performed using a direct current or an alternating current in an aqueous solution mainly containing nitric acid, and (4) an acid or alkali aqueous solution is used. A method for producing an aluminum support for a lithographic printing plate, characterized in that chemical etching or electrolytic polishing using an aluminum plate as an anode is performed in the aluminum plate, and the aluminum plate is dissolved in 0.01 to 10 g / m ^2. is there. In the present invention, by providing fine irregularities on the aluminum plate, the minute irregularities cause irregular reflection, making it difficult to see streaks and uneven surface quality. Also, due to the presence of fine irregularities, 0.1% of the aqueous
There is also an effect that honeycomb pits of up to 3 μm are uniformly generated regardless of the crystal orientation. In addition, it is possible to generate uniform honeycomb pits even on an aluminum plate in which a relatively large amount of trace elements is contained in the aluminum plate and uniform electrochemical surface roughening is difficult in a nitric acid solution.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the roughening method of the present invention will be described in detail. Embodiment 1 An aluminum plate is sequentially placed in an aqueous solution mainly composed of (1) hydrochloric acid using an alternating current at an electric quantity of 1 to 300 C / dm ² ,
Preliminary electrochemical surface roughening is performed, and (2) chemical etching in an acid or alkali aqueous solution or electrolytic polishing using an aluminum plate as an anode is performed, and the aluminum plate is subjected to 0.01 to 1.5. / M ² , (3) electrochemical surface roughening using DC or AC in an aqueous solution mainly composed of nitric acid, and (4) chemical etching in an aqueous acid or alkali solution, or aluminum etching. Perform an electrolytic polishing process using the plate as an anode and remove the aluminum plate from 0.01 to 10
g / m ^{2. A} method for producing an aluminum support for a lithographic printing plate, characterized by dissolving g / m ² .

Embodiment 2 Before preliminary electrochemical surface roughening in an aqueous hydrochloric acid solution
Then, the aluminum plate is sequentially (1) mechanically roughened,
Uses direct current or alternating current in an aqueous solution mainly containing nitric acid.
(2) Acid or alkali aqueous solution
Chemical etching in liquid or aluminum plate
Electrolytic polishing treatment was performed using the anode as an anode, and the aluminum plate was treated with 0.1%.
01-20g / dm ^TwoEmbodiments characterized by dissolving
A method for producing an aluminum support for a lithographic printing plate according to aspect 1. What
Use DC or AC in an aqueous solution mainly containing nitric acid
Acid or alkali after electrochemical roughening
Dissolution of aluminum in chemical etching in aqueous solution
The amount is 0.01 to 1.5 g / m^TwoIt is preferred that
Chemically dissolve aluminum plate in alkaline aqueous solution
Alternatively, use an aluminum plate as the anode in an alkaline aqueous solution
After electropolishing, desmut treatment in acidic aqueous solution
Is preferred. After the surface roughening treatment,
Anodizing to increase the wear resistance of the surface of the aluminum plate
Preferably, a treatment is applied. Furthermore, anodizing treatment
After the aluminum is applied, the surface of the aluminum
Preferably, treatment is performed. In addition, graining and
After the anodizing treatment, a sealing treatment is preferably performed.

[0008] The aluminum plate used in the present invention is selected from a pure aluminum plate, an alloy plate containing aluminum as a main component and a trace amount of a different element, or a plastic film on which aluminum is laminated or vapor-deposited. The different elements contained in the aluminum alloy include silicon,
Iron, nickel, manganese, copper, magnesium, chromium,
Examples include zinc, bismuth, titanium, and vanadium. Conventionally known materials, such as JIS, usually described in the 4th edition of the Aluminum Handbook (1990, Japan Light Metal Association)
A 1050 material, JIS A 3103 material, JIS
A 3005 material, JIS A 1100 material, JIS A
A 3004 material or an alloy to which 5% by weight or less of magnesium is added for the purpose of increasing the tensile strength can be used. In particular, it is suitable for roughening an aluminum plate in which a failure due to the direction of crystal grains occurs. The aluminum plate may be manufactured by a continuous casting and rolling method in addition to an aluminum plate by a normal DC casting method. As a method of continuous casting and rolling, twin roll method, belt caster method,
A block caster method or the like can be used. The thickness of the aluminum plate used in the present invention is approximately 0.1 to
It is about 0.6 mm. For aluminum plates that are subject to uneven processing due to differences in aluminum dissolution rate due to crystal grain orientation differences in alkali etching, intermediate annealing, or soaking, or intermediate annealing and soaking are omitted from DC casting. Aluminum plate manufactured by
An aluminum plate manufactured by omitting the intermediate annealing treatment from the continuous casting method is preferable.

The aluminum plate used in the present invention, in which processing unevenness is likely to occur due to a difference in the aluminum dissolution rate due to a difference in crystal grain orientation in alkali etching, is referred to as a streak-like uneven processing called a streak after the alkali etching.
An aluminum plate that is easy to appear as uneven surface quality. Further, in the surface roughening method of the present invention, the surface of the aluminum plate is mirror-finished by buffing, and the aluminum plate is subjected to 15 g / g.
For the purpose of dissolving m ^2, the surface of an aluminum plate which was alkali-etched in an aqueous caustic soda solution and desmutted in an acidic aqueous solution was observed by AFM.
Hereinafter, it is more preferable to uniformly roughen an aluminum alloy plate having a thickness of 0.02 μm or more and 0.2 μm or less. When the aluminum plate is buffed and the surface etched with hydrofluoric acid is observed, the width of the crystal grains long in the rolling direction is about 0.01 mm or more and 10 mm or less, and the length is 0.5 m
m or more and 300 mm or less. Rolling direction The width of the crystal grains long in the rolling direction is preferably 5 mm or less, more preferably 3 mm or less.

As the apparatus used in the present invention for electrochemical surface roughening or electrolytic polishing using direct current or alternating current, any known apparatus used for continuous surface treatment of a metal web can be applied. The aluminum plate roughened by the present invention is preferably subjected to an anodic oxidation treatment in order to increase the abrasion resistance of the surface of the aluminum plate. After the anodizing treatment or the anodizing treatment and the immersion treatment, the photosensitive layer or the intermediate layer and the photosensitive layer are applied and dried according to a conventional method to obtain a PS plate having excellent printing performance. A mat layer may be provided on the photosensitive layer in order to improve the adhesion to the lith film during vacuum baking. A back coat layer may be provided on the back surface for the purpose of preventing aluminum from dissolving during development. The present invention can be applied to the production of PS plates that are processed not only on one side but also on both sides. INDUSTRIAL APPLICABILITY The present invention can be applied not only to the roughening of an aluminum support for a lithographic printing plate but also to the roughening of any aluminum plate.

Preliminary electrochemical surface roughening in an aqueous solution mainly containing hydrochloric acid using an alternating current at an electric quantity of 1 to 300 C / dm ² , an aqueous solution mainly containing hydrochloric acid according to the present invention is: What is used for the electrochemical surface roughening treatment using ordinary direct current or alternating current can be used. A nitric acid ion such as aluminum nitrate, sodium nitrate, ammonium nitrate, aluminum chloride, chloride, etc. is added to an aqueous hydrochloric acid solution of 1 to 100 g / liter. One or more hydrochloric acid or nitric acid compounds having hydrochloric acid ions such as sodium, ammonium chloride and the like can be used by adding from 1 g / liter to saturation. Metals contained in aluminum alloys such as iron, copper, manganese, nickel, titanium, magnesium, and silica may be dissolved in the aqueous solution mainly containing hydrochloric acid. Further, hypochlorous acid may be added. In order to preliminarily generate fine irregularities using an alternating current in an aqueous solution mainly composed of hydrochloric acid, a solution temperature of 15 to
An aluminum salt was added to an aqueous solution containing hydrochloric acid at 5 to 15 g / liter at 45 ° C.
An aqueous solution of 0 g / liter is particularly preferred. As an additive, a device, a power supply, a current density, a flow rate, and a temperature used in an aqueous solution mainly containing hydrochloric acid, those used for known electrochemical surface roughening are used, and an aqueous solution mainly containing nitric acid or hydrochloric acid is used. preferable. As a power source used for electrochemical surface roughening, AC or DC is used, and AC is particularly preferable. The amount of electricity that the aluminum plate participates in the anodic reaction due to electrochemical surface roughening in an aqueous solution mainly containing hydrochloric acid,
It can be selected from the range of 1 to 300 C / dm ² ,
Preferably ^{C / dm 2, 10~100C / dm} 2 are particularly preferred.

After the formation of fine irregularities by electrochemical surface roughening, a smut or an oxide film is formed. Therefore, in order to uniformly perform the next electrochemical surface roughening, an acid or alkali aqueous solution is used. The aluminum plate is preferably subjected to a mild etching treatment to dissolve 0.01 to 3 g / m ² ,
Particularly preferred is 1 to 1.5 g / m ² . Preliminary electrochemical surface roughening of 1 to 300 C / dm ² of electricity using an alternating current in an aqueous solution mainly containing hydrochloric acid means that pits are formed uniformly over the entire surface without any unetched portions. It is particularly preferable that, even if an unetched portion exists, the unetched etched portion is uniformly dispersed.

Electropolishing Treatment in Alkaline Aqueous Solution The electropolishing treatment in an alkali aqueous solution in the present invention is performed by using an alkaline substance such as sodium hydroxide, potassium hydroxide, sodium carbonate and sodium phosphate alone or
Alternatively, use an aqueous solution of a mixture thereof, or a mixture of an alkaline substance and zinc hydroxide or aluminum hydroxide, or a mixture of these alkaline substances and salts such as sodium chloride or potassium chloride, and electrically deoxidize the material. It refers to the case where aluminum is used as an anode and electrolytic treatment is performed at such an electrolytic solution composition, temperature and concentration. In order to stably form a uniform oxide film, hydrogen peroxide, phosphate, or the like may be added at a concentration of 1 wt% or less. A known aqueous solution used for electrolytic polishing can be used, but an aqueous solution mainly containing sodium hydroxide is preferable. Preferably, it is an aqueous solution containing 2 to 30% by weight of sodium hydroxide, particularly an aqueous solution containing 3 to 20% of sodium hydroxide. Liquid temperature 10 to 90 ° C (preferably 35 to 6)
0 ° C.), current density 1 to 200 A / dm ² (preferably 2
0 to 80 A / dm ² ) and the electrolysis time can be selected from the range of 1 to 180 seconds. As the current, DC, pulse DC, and AC can be used, but continuous DC is preferable. As the electrolytic treatment apparatus, those used in known electrolytic treatment such as a flat type tank and a radial type tank can be used. After the treatment is completed, before or after, or before or after the electropolishing treatment, it is preferable to perform draining with a nip roller and washing with water to prevent the treatment liquid from being carried into the next step, or before and after the aluminum plate. ~ 3 g / m ² dissolve
More preferably, chemical etching is performed in an acid or alkali aqueous solution.

Electropolishing Treatment in Acidic Aqueous Solution For the electropolishing treatment of the aluminum plate in the acidic aqueous solution referred to in the present invention, a known aqueous solution used for electrolytic polishing can be used.
Preferably, it is an aqueous solution mainly containing sulfuric acid or phosphoric acid. Particularly preferably, sulfuric acid or phosphoric acid is 20 to 90 wt.
% (Preferably 40 to 80 wt%). Liquid temperature 10-90 ° C (preferably 50-80 ° C), current density 1-200 A / dm ² (preferably 5-80 A / dm ²
dm ² ) and the electrolysis time can be selected from the range of 1 to 180 seconds. Sulfuric acid, phosphoric acid, chromic acid, hydrogen peroxide, citric acid, boric acid, hydrofluoric acid, phthalic anhydride and the like may be added to the aqueous solution in an amount of 1 to 50% by weight. In addition to aluminum, an alloy component contained in an aluminum alloy may be contained in an amount of 0 to 10 wt%. The sulfate ion or phosphate ion concentration and the aluminum ion concentration are preferably used so as not to crystallize even at room temperature. The current can be direct current, pulse direct current, alternating current,
Continuous direct current is preferred. As the electrolytic treatment apparatus, those used in known electrolytic treatment such as a flat type tank and a radial type tank can be used. After the treatment is completed, before or after, or before or after the electropolishing treatment, it is preferable to perform draining with a nip roller and washing with water to prevent the treatment liquid from being carried into the next step, or before and after the aluminum plate. More preferably, the chemical etching is performed in an aqueous acid or alkali solution that dissolves 3 g / m ² .

Chemical Etching Treatment in Acid or Alkaline Aqueous Solution The concentration of the alkaline aqueous solution is preferably 1 to 30% by weight, and the alloy component contained in the aluminum alloy as well as aluminum may be contained in the range of 0 to 10% by weight. As the alkaline aqueous solution, an aqueous solution mainly containing caustic soda is particularly preferable. The liquid temperature is preferably from room temperature to 95 ° C. for 1 to 120 seconds. As the acid that can be used for the acidic aqueous solution, phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid containing two or more of these acids can be used. The concentration of the acidic aqueous solution is preferably 0.5 to 65 wt%, and the alloy component contained in the aluminum alloy may be 0 to 10 wt% in addition to aluminum. Liquid temperature is 30-9
The treatment is preferably performed at 5 ° C. for 1 to 120 seconds. Sulfuric acid is particularly preferred as the acidic aqueous solution. The sulfuric acid concentration and the aluminum concentration are preferably selected from a range that does not crystallize at room temperature. After the completion of the etching process, it is preferable to perform draining with a nip roller and washing with water by spraying so as not to bring the processing solution into the next step.

Desmut treatment in an acidic aqueous solution When chemical etching is performed using an alkaline aqueous solution, smut is generally formed on the surface of aluminum. In this case, phosphoric acid, nitric acid, sulfuric acid, chromic acid, Desmut treatment is performed with hydrochloric acid or a mixed acid containing two or more of these acids. The concentration of the acidic aqueous solution is preferably 0.5 to 60% by weight. Further, in the acidic aqueous solution, not only aluminum but also alloy components contained in the aluminum alloy are 0 to 5 wt.
% May be dissolved. The solution temperature is from room temperature to 95 ° C., and the treatment time is preferably from 1 to 120 seconds. After the end of the desmutting treatment, it is preferable to perform draining with a nip roller and washing with water by spraying so as not to bring the treatment liquid into the next step.

Mechanical surface roughening treatment The mechanical surface roughening referred to in the present invention means that the bristle diameter is 0.2-1.
It is advantageous to mechanically roughen with a rotating nylon brush roll of 61 mm and a slurry liquid supplied to the surface of the aluminum plate. Known abrasives can be used, but silica sand, quartz, aluminum hydroxide or a mixture thereof is preferred. The details are described in JP-A-6-135175 and JP-B-50-40047. The specific gravity of the slurry liquid is preferably from 1.05 to 1.3. Of course, a method of spraying a slurry liquid, a method of using a wire brush, or a method of transferring the surface shape of a roll with irregularities to an aluminum plate may be used. Other methods are described in JP-A-55-074898 and JP-A-61-16.
2351 and JP-A-63-104889. Aqueous solution mainly composed of nitric acid The aqueous solution mainly composed of nitric acid as used in the present invention can be used for the electrochemical surface roughening treatment using a normal direct current or alternating current. ,
One or more of nitric acid ions such as aluminum nitrate, sodium nitrate, ammonium nitrate, etc., and hydrochloric acid or nitric acid compound having hydrochloric acid ions such as aluminum chloride, sodium chloride, ammonium chloride, etc. may be added to 1 g / liter to saturation. it can. Metals contained in aluminum alloys such as iron, copper, manganese, nickel, titanium, magnesium and silica may be dissolved in the aqueous solution mainly containing nitric acid. Particularly preferably, nitric acid 5-2
Aluminum ions in an aqueous solution of 0 g / liter
It is preferable to use a solution to which aluminum chloride and aluminum nitrate are added so as to be 50 g / liter. The temperature is preferably from 10 to 95 ° C, more preferably from 40 to 80 ° C.

Electrochemical surface roughening using alternating current The acidic aqueous solution referred to in the present invention may be the one used for usual electrochemical surface roughening using direct current or alternating current. Advantageously, it can be selected from the aqueous solution mainly composed of nitric acid or the aqueous solution mainly composed of hydrochloric acid. The AC power supply waveform used for electrochemical roughening is a sine wave, square wave,
Although a trapezoidal wave, a triangular wave, or the like can be used, a rectangular wave or a trapezoidal wave is preferable, and a trapezoidal wave is particularly preferable. The frequency is preferably from 0.1 to 250 Hz. FIG. 1 shows an example of a trapezoidal wave preferably used in the present invention. In trapezoidal waves,
The time tp from the time when the current reaches 0 to the peak is 0.1 to 0.1.
10 msec is preferable, and 0.3 to 2 msec is particularly preferable. Due to the influence of the impedance of the power supply circuit, t
If p is less than 1, a large power supply voltage is required at the time of rising of the current waveform, and the equipment cost of the power supply increases. 1
If the time is longer than 0 msec, it is likely to be affected by a trace component in the electrolytic solution, and it is difficult to perform uniform surface roughening.
The condition of one cycle of alternating current used for electrochemical surface roughening is that the ratio tc / ta of the anode reaction time ta to the cathode reaction time tc of the aluminum plate is 1 to 20, and the quantity of electricity Qc when the aluminum plate is an anode and the anode Electricity Qa at time
Is between 0.3 and 20, the anode reaction time ta
Is preferably in the range of 5 to 1000 msec. tc / ta is more preferably from 2.5 to 15. Qc / Qa is more preferably from 2.5 to 15. The current density is the peak value of the trapezoidal wave and is 10 to 20 for both the anode cycle side Ia and the cathode cycle side Ic of the current.
0 A / dm ² is preferred. Ic / Ia is preferably in the range of 0.3 to 20. The total amount of electricity involved in the anodic reaction of the aluminum plate at the time when the electrochemical graining is completed is preferably from 1 to 1000 C / dm ² . As the electrolytic cell used for electrochemical surface roughening using alternating current in the present invention, an electrolytic cell used for a known surface treatment such as a vertical type, a flat type, and a radial type can be used.
A radial electrolytic cell as described in 300 is particularly preferred. The electrolytic solution passing through the electrolytic cell may be parallel or counter to the progress of the aluminum web. One or more AC power supplies can be connected to one electrolytic cell. Two or more electrolytic cells can be used. The apparatus shown in FIG. 2 can be used for electrochemical surface roughening using alternating current. When two or more electrolytic cells are used, the electrolytic conditions may be the same or different. The aluminum plate W is wound around a radial drum roller 52 immersed in a main electrolytic cell 50 and subjected to electrolytic treatment by main electrodes 53a and 53b connected to an AC power supply 51 in a transport process. Electrolyte 5
5 is supplied from an electrolyte supply port 54 through a slit 56 to an electrolyte passage 57 between the radial drum roller 52 and the main poles 53a and 53b. The aluminum plate W treated in the main electrolytic cell 50 is then subjected to electrolytic treatment in the auxiliary anode cell 60.
An auxiliary anode 58 is disposed in the auxiliary anode tank 60 so as to face the aluminum plate W, and the electrolytic solution 55 is supplied so as to flow in a space between the auxiliary anode 58 and the aluminum plate W.

Electrochemical surface roughening using a direct current In the present invention, the electrochemical surface roughening using a direct current is performed by applying a direct current between an aluminum plate and an electrode facing the aluminum plate. It refers to the method of roughening the surface. As the electrolytic solution, those used for electrochemical surface roughening treatment using a known direct current or alternating current can be used. Advantageously,
It can be selected from the aqueous solution mainly containing nitric acid or the aqueous solution mainly containing hydrochloric acid. The temperature is preferably from 10 to 80C. As a processing apparatus used for electrochemical surface roughening using a direct current, a known apparatus using a direct current can be used. However, as described in JP-A-1-140994, a pair of at least one anode and one cathode are used. It is preferable to use alternately arranged devices. An example of a known device is disclosed in Japanese Patent Application No. 5-682.
04, Japanese Patent Application No. 6-205657, Japanese Patent Application No. 6-2105
0, JP-A-61-19115, JP-B-57-44760.
And so on. Also, between the conductor roll contacting the aluminum plate and the cathode facing this,
A direct current may be applied to perform an electrochemical surface roughening treatment using the aluminum plate as an anode. After the completion of the electrolytic treatment, it is preferable to perform draining with a nip roller and washing with water by spraying so as not to bring the treatment liquid into the next step. It is preferable to use a direct current having a ripple ratio of 20% or less as the direct current used for electrochemical surface roughening. The current density is preferably 10 to 200 A / dm ² , and the amount of electricity when the aluminum plate is an anode is preferably 1 to 1000 C / dm ² . The anode can be selected from known electrodes for oxygen generation, such as ferrite, iridium oxide, platinum, and platinum clad or plated with a valve metal such as titanium, niobium, or zirconium. The cathode can be selected from carbon, platinum, titanium, niobium, zirconium, stainless steel, and an electrode used for a fuel cell cathode.

Anodizing Treatment Anodizing treatment is performed to increase the abrasion resistance of the surface of the aluminum plate. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte that forms a porous oxide film can be used. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixture thereof is used. The concentration of these electrolytes is appropriately determined by the type of electrolyte. Since the anodizing treatment conditions vary depending on the electrolyte used, they cannot be specified unconditionally, but generally the concentration of the electrolyte is 1 to 80 wt%, the liquid temperature is 5 to 70 ° C., and the current density is 1 to 60 A / dm ^2. , Voltage 1
It is suitable that the electrolysis time is in the range of 100 to 100 V and the electrolysis time is 10 seconds to 300 seconds. In the sulfuric acid method, the treatment is usually performed with a direct current, but an alternating current can also be used. The amount of the anodic oxide film is suitably in the range of 1 to 10 g / m ² . When the amount is less than 1 g / m ² , the printing durability is insufficient, and the non-image portion of the lithographic printing plate is easily damaged, and at the same time, the ink adheres to the scratched portion, that is, so-called scratch stain is easily generated. .
After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment as necessary. U.S. Pat. Nos. 2,714,066 and 318 as hydrophilic treatments used in the present invention.
No. 1461, No. 3280734 and No. 3902732
There is an alkali metal silicate (for example, sodium silicate aqueous solution) method as disclosed in each of the above-mentioned specifications. In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated. In addition, Japanese Patent Publication No. 36-22
No. 063, and potassium fluoride zirconate disclosed in US Pat. No. 3,276,868 and 41534.
For example, a method of treating with polyvinyl phosphonic acid as disclosed in the specifications of JP-A Nos. 61 and 4689272 is used. After graining and anodizing,
Those subjected to a sealing treatment are also preferable. Such a sealing treatment is performed by immersion in hot water and a hot aqueous solution containing an inorganic salt or an organic salt, a steam bath or the like.

[0021]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples.
The invention is not limited to these examples. Example 1 The intermediate casting process and the soaking process were omitted in the DC casting method, and the thickness was 0.24 mm, in which streak and surface quality unevenness were easily generated by chemical etching in an acid or alkali aqueous solution.
The treatment was continuously performed using a JIS A 1050 aluminum plate having a width of 1030 mm. (1) Mechanical surface roughening treatment: While supplying a suspension of silica sand and water having a specific gravity of 1.12 to the surface of an aluminum plate as a polishing slurry, mechanically roughening the surface with a rotating roller-shaped nylon brush. Was done. The nylon brush was made of nylon 6/10, and had a bristle length of 50 mm and a bristle diameter of 0.48 mm. Nylon brush is Φ300m
A hole was made in a stainless steel tube having a diameter of m and the hair was planted so as to be dense. Three rotating brushes were used. The distance between the two support rollers (Φ200 mm) below the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 6 kW plus the load before pressing the brush roller against the aluminum plate.
The direction of rotation of the brush was the same as the direction of movement of the aluminum plate. Then, it was washed with water. The moving speed of the aluminum plate was 50 m / min. (2) Etching treatment in alkaline aqueous solution: The aluminum plate was immersed in an aqueous solution containing 27 wt% of NaOH and 6.5 wt% of aluminum ions at 70 ° C. to perform the etching treatment on the aluminum plate. The dissolution amount of the aluminum plate was 10 g / m ² . Thereafter, a water washing treatment was performed. (3) Desmut treatment ^: Next, an aqueous solution containing 1 wt% of hydrochloric acid was immersed in 35 ° C. for 10 seconds to perform desmut treatment. Thereafter, a water washing treatment was performed. (4) Preliminary electrochemical surface-roughening treatment in an aqueous hydrochloric acid solution: Electrochemical surface-roughening treatment was continuously performed using the AC voltage in FIG. At this time, the electrolytic solution was a 1 wt% aqueous solution of hydrochloric acid (aluminum ion 0.5 w
t%) and the liquid temperature was 35 ° C. In the AC power supply waveform, the time TP until the current value reaches a peak from zero is 1 msec.
c, Duty ratio 1: 1, 60 Hz, trapezoidal rectangular wave alternating current was used, and a carbon electrode was used as a counter electrode to perform electrochemical surface roughening treatment. Ferrite was used for the auxiliary anode. The current density is 50 A / dm ² at the peak value of the current, and the electric quantity is 40 C / dm ² as the total electric quantity when the aluminum plate is the anode.
dm ² . 5 of the current flowing from the power supply is
%. Thereafter, water washing by spraying was performed.

(6) Desmut treatment: Next, 1 wt% of nitric acid
An aqueous solution (containing 0.5 wt% of aluminum ions and 0.007 wt% of ammonium ions) was immersed in a 35 ° C. for 10 seconds to perform a desmut treatment. Thereafter, a water washing treatment was performed. (7) Electrochemical surface roughening treatment in nitric acid aqueous solution: FIG.
Electrochemical surface roughening treatment was performed continuously using the AC voltage of FIG. At this time, the electrolytic solution is nitric acid 1w
A t% aqueous solution (containing 0.5 wt% of aluminum ions and 0.007 wt% of ammonium ions) was at a liquid temperature of 50 ° C. In the AC power supply waveform, the time TP until the current value reaches the peak from zero is 1 msec, the duty ratio is 1: 1, 60
Using a rectangular-wave alternating current of Hz and trapezoid, electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The current density was 50 A / dm ² at the peak value of the current, and the quantity of electricity was 230 C / dm ^{2 as} the sum of the quantity of electricity when the aluminum plate was the anode. 5% of the current flowing from the power supply was diverted to the auxiliary anode. Thereafter, water washing by spraying was performed. (8) Etching treatment in alkaline aqueous solution: The aluminum plate was immersed in an aqueous solution containing 26 wt% of NaOH and 6.5 wt% of aluminum ions at 45 ° C. to perform the etching treatment of the aluminum plate. The dissolution amount of the aluminum plate was 1 g / m ² . Thereafter, a water washing treatment was performed. (9) Desmut treatment: Thereafter, a water washing treatment was performed. Next, it was immersed in an aqueous solution containing 25% by weight of sulfuric acid at 60 ° C. to perform desmut treatment. Thereafter, a water washing treatment was performed. (10) Anodizing treatment: sulfuric acid concentration 15 wt.
% Aqueous solution (containing 0.5wt% aluminum ion)
The anodic oxidation treatment was performed using a DC voltage at a current density of 2 A / dm ^{2 so} that the amount of the anodic oxide film was 2.4 g / m ² . Thereafter, water washing by spraying was performed. There were no streaks or surface unevenness due to the orientation of crystal grains on the surface of this aluminum plate. The average surface roughness of this aluminum plate was about 0.6 μm. The intermediate layer and the photosensitive layer are applied to this aluminum plate, dried,
A positive PS plate having a dry film thickness of 2.0 g / m ² was prepared. This PS
When printing was performed using the plate, a good printing plate was obtained.

Example 2 The aluminum substrate after the anodic oxidation treatment of Example 1 was immersed in an aqueous solution of sodium silicate 2.5 wt% and 70 ° C. for 14 seconds for the purpose of hydrophilization treatment, and then washed with a spray and dried. did. After each treatment and washing with water, the liquid was drained with a nip roller. An intermediate layer and a negative photosensitive layer were applied to the treated aluminum plate and dried to prepare a PS plate. This P
When the S plate was printed, it was a good printing plate.

Embodiment 3 Instead of the chemical etching treatment in the alkali aqueous solution of (8) of Embodiment 1, at 35 ° C. in an aqueous solution containing 9 wt% of caustic soda and 0.5 wt% of aluminum ions.
The surface was roughened in the same manner as in Example 1 except that the aluminum plate was used as an anode at a current density of 20 A / dm ² and the electrolytic polishing was performed so that the amount of aluminum dissolved was 1 g / m ² . An intermediate layer and a negative photosensitive layer were applied to the treated aluminum plate and dried to prepare a PS plate. This P
When the S plate was printed, it was a good printing plate.

Example 4 The aluminum substrate after the anodic oxidation treatment of Example 3 was immersed in an aqueous solution of sodium silicate 2.5 wt%, 70 ° C. for 14 seconds for the purpose of hydrophilization treatment, then washed with a spray and dried. did. After each treatment and washing with water, the liquid was drained with a nip roller. An intermediate layer and a negative photosensitive layer were applied to the treated aluminum plate and dried to prepare a PS plate. This P
When the S plate was printed, it was a good printing plate.

Example 5 The intermediate casting process and the soaking process were omitted in the DC casting method. The thickness was 0.24 mm, in which streaks and surface unevenness were easily generated by chemical etching in an acid or alkali aqueous solution.
The treatment was continuously performed using a JIS A 1050 aluminum plate having a width of 1030 mm. (1) Mechanical surface roughening treatment: While supplying a suspension of silica sand and water having a specific gravity of 1.12 to the surface of an aluminum plate as a polishing slurry, mechanically roughening the surface with a rotating roller-shaped nylon brush. Was done. Nylon brush material is 6
-Using 10 nylon, the bristle length was 50 mm, and the bristle diameter was 0.295 mm. Nylon brush is Φ300m
A hole was made in a stainless steel tube having a diameter of m and the hair was planted so as to be dense. Three rotating brushes were used. The distance between the two support rollers (Φ200 mm) below the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 4 kw plus with respect to the load before pressing the brush roller against the aluminum plate.
The direction of rotation of the brush was the same as the direction of movement of the aluminum plate. Then, it was washed with water. The moving speed of the aluminum plate was 50 m / min. (2) Etching treatment in alkaline aqueous solution: The aluminum plate was immersed in an aqueous solution containing 27 wt% of NaOH and 6.5 wt% of aluminum ions at 70 ° C. to perform the etching treatment on the aluminum plate. The dissolution amount of the aluminum plate was 6 g / m ² . Thereafter, a water washing treatment was performed. (3) Desmutting treatment: Next, an aqueous solution containing 1 wt% of hydrochloric acid was immersed in 35 ° C. for 10 seconds to perform desmutting treatment. Thereafter, a water washing treatment was performed. (4) Preliminary electrochemical surface-roughening treatment in an aqueous hydrochloric acid solution: The electrochemical surface-roughening treatment was continuously performed using the AC voltage of FIG. At this time, the electrolytic solution was a 1 wt% aqueous solution of hydrochloric acid (aluminum ion 0.5 w
t%) and the liquid temperature was 35 ° C. In the AC power supply waveform, the time TP until the current value reaches a peak from zero is 1 msec.
c, Duty ratio 1: 1, 60 Hz, trapezoidal rectangular wave alternating current was used, and an electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode.
The current density is 50 A / dm ₂ at the peak value of the current, and the quantity of electricity is 25 C / dm 2 as the sum of the quantity of electricity when the aluminum plate is the anode.
² (Example 5-1), 40 C / dm ² (Example 5-2),
100 C / dm ² (Example 5-3), 150 C / dm
² (Example 5-4). 5% of the current flowing from the power supply was diverted to the auxiliary anode. Thereafter, water washing by spraying was performed.

(5) Etching treatment in alkaline aqueous solution: The aluminum plate was etched by immersing it in an aqueous solution containing 26 wt% of NaOH and 6.5 wt% of aluminum ions at 45 ° C. The dissolution amount of the aluminum plate was 0.3 g / m ² . Thereafter, a water washing treatment was performed. (4) Desmut treatment: Next, nitric acid 1 wt% (aluminum ion 0.5 wt%, ammonium ion 0.007
(% by weight) was immersed in an aqueous solution at 35 ° C. for 10 seconds to perform a desmut treatment. Thereafter, a water washing treatment was performed. (5) Electrochemical surface roughening treatment in nitric acid aqueous solution: FIG.
Electrochemical surface roughening treatment was performed continuously using the AC voltage of FIG. At this time, the electrolytic solution is nitric acid 1w
A t% aqueous solution (containing 0.5 wt% of aluminum ions and 0.007 wt% of ammonium ions) was at a liquid temperature of 50 ° C. In the AC power supply waveform, the time TP until the current value reaches the peak from zero is 1 msec, the duty ratio is 1: 1, 60
Using a rectangular-wave alternating current of Hz and trapezoid, electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The current density was 50 A / dm ² at the peak value of the current, and the quantity of electricity was 65 C / dm ^{2 as} the sum of the quantity of electricity when the aluminum plate was the anode. 5% of the current flowing from the power supply was diverted to the auxiliary anode. Thereafter, water washing by spraying was performed. (6) Etching treatment in alkaline aqueous solution: The aluminum plate was immersed in an aqueous solution containing 27 wt% of NaOH and 6.5 wt% of aluminum ions at 40 ° C. to perform the etching treatment on the aluminum plate. The dissolution amount of the aluminum plate was 1 g / m ² . Thereafter, a water washing treatment was performed. (7) Desmut treatment: Thereafter, a water washing treatment was performed. Next, it was immersed in an aqueous solution containing 25% by weight of sulfuric acid at 60 ° C. to perform desmut treatment. Thereafter, a water washing treatment was performed. (8) Anodizing treatment: sulfuric acid concentration of 15 wt% at a liquid temperature of 35 ° C
In an aqueous solution (containing 0.5 wt% of aluminum ions),
Using a DC voltage, anodizing treatment was performed at a current density of 2 A / dm ^{2 such} that the amount of anodized film became 1.2 g / m ² . Thereafter, water washing by spraying was performed. No streaks or uneven surface quality due to the orientation of the crystal grains occurred on the surface of the aluminum plate. The average surface roughness of this aluminum plate was about 0.35 μm. The intermediate layer and the photosensitive layer are applied to this aluminum plate and dried, and a positive type PS for proof printing having a dry film thickness of 2.0 g / m ^2.
Created a version. When printing was performed using this PS plate, a good printing plate having no sponge and good ink adhesion was obtained.

Example 6 Instead of the chemical etching treatment in an alkaline aqueous solution of Example 5 (8), a current density of 20 A at 35 ° C. in an aqueous solution containing 9 wt% of caustic soda and 0.5 wt% of aluminum ions. A surface roughening treatment was performed in the same manner as in Example 5, except that the aluminum plate was used as an anode at / dm ² and the electrolytic polishing treatment was performed so that the amount of aluminum dissolved was 4 g / m ² . An intermediate layer and a negative photosensitive layer were applied to the treated aluminum plate and dried to prepare a PS plate. When this PS plate was printed, it was a good printing plate.

Example 7 The intermediate casting process and the soaking process were omitted in the DC casting method, and a streak and a surface unevenness were easily generated by chemical etching in an acid or alkali aqueous solution.
The treatment was continuously performed using a JIS A1050 aluminum plate having a width of 1030 mm. (1) Etching treatment in alkaline aqueous solution: The aluminum plate was etched by dipping in an aqueous solution containing 27 wt% of NaOH and 6.5 wt% of aluminum ions at 70 ° C. The dissolution amount of the aluminum plate was 3 g / m ² . Thereafter, a water washing treatment was performed. (2) Desmutting treatment: Next, an aqueous solution containing 1 wt% of hydrochloric acid was immersed in 35 ° C. for 10 seconds to perform desmutting treatment. Thereafter, a water washing treatment was performed. (3) Electrochemical surface roughening treatment (treatment for forming fine irregularities) in an aqueous hydrochloric acid solution: the AC voltage shown in FIG.
Electrochemical surface roughening treatment was performed continuously using a tank.
At this time, the electrolytic solution was a 1 wt% aqueous solution of hydrochloric acid (containing 0.5 wt% of aluminum ions), and the liquid temperature was 35 ° C. The AC power supply waveform is obtained by performing electrochemical roughening treatment using a carbon electrode as a counter electrode using a trapezoidal rectangular wave AC with a time TP until the current value reaches a peak from zero to a peak of 1 msec, a duty ratio of 1: 1, 60 Hz. went. Ferrite was used for the auxiliary anode. The current density is 50 A /
dm ² , and the amount of electricity was 50 C / dm ² in total of the amount of electricity when the aluminum plate was an anode. 5% of the current flowing from the power supply was diverted to the auxiliary anode. Thereafter, water washing by spraying was performed. (4) Etching treatment in an alkaline aqueous solution: an aluminum plate was treated with 5 wt% of NaOH and 0.1% of aluminum ions.
The aluminum plate was etched by immersing it in an aqueous solution containing 5 wt% at 45 ° C. The dissolution amount of the aluminum plate was 0.3 g / m ² . Thereafter, a water washing treatment was performed.

(5) Desmut treatment: Next, 1 wt% of nitric acid
An aqueous solution (containing 0.5 wt% of aluminum ions and 0.007 wt% of ammonium ions) was immersed in a 35 ° C. for 10 seconds to perform a desmut treatment. Thereafter, a water washing treatment was performed. (6) Electrochemical surface roughening treatment in aqueous nitric acid solution: FIG.
Electrochemical surface roughening treatment was performed continuously using the AC voltage of FIG. At this time, the electrolytic solution is nitric acid 1w
A t% aqueous solution (containing 0.5 wt% of aluminum ions and 0.007 wt% of ammonium ions) was at a liquid temperature of 50 ° C. In the AC power supply waveform, the time TP until the current value reaches the peak from zero is 1 msec, the duty ratio is 1: 1, 60
Using a rectangular-wave alternating current of Hz and trapezoid, electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The current density was 50 A / dm ² at the peak value of the current, and the amount of electricity was 180 C / dm ^{2 as} the total amount of electricity when the aluminum plate was the anode (Example 7-1), 23
0 C / dm ² (Example 7-2) It was 500 C / dm ² (Example 7-3). 5% of the current flowing from the power supply was diverted to the auxiliary anode. Thereafter, water washing by spraying was performed. (7) Etching treatment in alkaline aqueous solution: The aluminum plate was immersed in an aqueous solution containing 27 wt% of NaOH and 6.5 wt% of aluminum ions at 40 ° C. to perform the etching treatment on the aluminum plate. The dissolution amount of the aluminum plate was 0.1 g / m ² . Thereafter, a water washing treatment was performed. (8) Desmut treatment ^: Thereafter, a water washing treatment was performed. Next, it was immersed in an aqueous solution containing 25% by weight of sulfuric acid at 60 ° C. to perform desmut treatment. Thereafter, a water washing treatment was performed. (9) Anodizing treatment: sulfuric acid concentration of 15 wt% at a liquid temperature of 35 ° C
In an aqueous solution (containing 0.5 wt% of aluminum ions),
Anodizing treatment was performed using a DC voltage at a current density of 2 A / dm ² and an anodized film amount of 2.4 g / m ² . Thereafter, water washing by spraying was performed. No streaks or uneven surface quality due to the orientation of the crystal grains occurred on the surface of the aluminum plate. The intermediate layer and the photosensitive layer are applied to this aluminum plate and dried, and the dried film thickness is 2.0 g.
A positive PS plate of / m ² was prepared. When printing was performed using this PS plate, a good printing plate was obtained.

Comparative Example 1 A roughening treatment was performed in the same manner as in Example 1 except that the treatments (3), (4) and (5) of Example 1 were not performed. On the surface of this aluminum plate, streaks and surface quality unevenness due to the orientation of crystal grains occurred.

[0032]

Industrial Applicability According to the present invention, an aluminum support for a lithographic printing plate, in which processing unevenness is unlikely to occur due to a difference in aluminum dissolution rate due to a difference in crystal grain orientation called a streak or surface quality unevenness, is manufactured at low cost. I was able to.

[Brief description of the drawings]

FIG. 1 is a waveform diagram showing an example of a trapezoidal waveform AC current power supply waveform preferably used for electrochemical graining of the present invention.

FIG. 2 is a schematic diagram showing an example of an electrolysis device used for electrochemical graining of the present invention.

[Explanation of symbols]

ta Anode reaction time tb Cathode reaction time tc Time until current reaches a peak from 0 Ia Peak current on anode cycle side Ic Peak current on cathode cycle side 50 Main electrolytic cell 51 AC power supply 52 Radial drum roller 53a, 53b Main electrode 54 Electrolyte supply port 55 Electrolyte 56 Auxiliary anode 60 Auxiliary anode tank W Aluminum plate

Continuation of front page (72) Inventor Akio Uesugi 4000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Inside Fujisha Shin Film Co., Ltd.

Claims (5)

[Claims] 1. An aluminum plate is sequentially placed in an aqueous solution mainly composed of (1) hydrochloric acid by using alternating current at 1 to 300 C / dm.
Preliminary electrochemical surface roughening with ² electricity quantities,
(2) Chemical etching in an acid or alkali aqueous solution or electrolytic polishing using an aluminum plate as an anode, dissolving the aluminum plate in an amount of 0.01 to 1.5 g / m ² , and (3) mainly using nitric acid (4) Chemical etching in an acid or alkali aqueous solution, or electrolytic polishing using an aluminum plate as an anode, A method for producing an aluminum support for a lithographic printing plate, comprising dissolving a plate in an amount of 0.01 to 10 g / m ² . 2. The aluminum plate is sequentially subjected to (1) mechanical roughening and (2) chemical etching in an acid or alkali aqueous solution or electrolytic polishing using the aluminum plate as an anode. From 0.01 to 20 g / m
² dissolve, (3) in an acid or alkali aqueous solution,
Preliminary electrochemical surface roughening is performed at an electric quantity of 1 to 300 C / dm ^{2 by} using (4) chemical etching in an acid or alkali aqueous solution, or electrolytic polishing using an aluminum plate as an anode. Perform aluminum plate 0.01 to
1.5 g / m ² dissolved, (5) electrochemical dampening using direct current or alternating current in an aqueous solution mainly composed of nitric acid, and (6) chemical etching in an aqueous acid or alkali solution, or A method for producing an aluminum support for a lithographic printing plate, comprising performing an electrolytic polishing treatment using an aluminum plate as an anode and dissolving the aluminum plate in an amount of 0.01 to 10 g / m ² . 3. The method according to claim 1, wherein after the electrochemical surface-roughening is performed using a direct current or an alternating current in an aqueous solution mainly containing nitric acid, the amount of aluminum dissolved by the chemical etching in an aqueous acid or alkali solution is 0. The method for producing an aluminum support for a lithographic printing plate according to claim 1, wherein the weight is from 0.01 to 1.5 g / m ² . 4. A desmutting treatment in an acidic aqueous solution after performing chemical etching in an acid or alkali aqueous solution or electrolytic polishing treatment using an aluminum plate as an anode. Item 4. The method for producing an aluminum support for a lithographic printing plate according to any one of Item 3, 5. The aluminum support for a lithographic printing plate according to claim 1, wherein anodizing treatment or anodizing treatment and hydrophilizing treatment are successively performed. Production method.