JP2001011698A - Surface roughening method and manufacture of aluminum supporting body for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface roughening method and a manufacturing method for an aluminum supporting body for lithographic printing plate by which treatment irregularity, called streak/picture quality irregularity, caused by the difference in the aluminum dissolving rate due to the difference in the azimuth of crystal grains is hardly generated and treatment irregularity caused by the electrochemical surface treatment is hardly generated. SOLUTION: In the surface roughening method for the aluminum supporting body for lithographic printing plate by which the desmutting treatment is executed in an acidic aqueous solution after the execution of the preliminarily electrochemical surface roughening in an aqueous solution comprising primarily hydrochloric acid, the desmutting treatment is executed by using an auxiliary electrode tank of an electrochemical surface roughening device while the aluminum plate is being subjected to the cathod electrolytic treatment. Further, the aluminum plate is subjected to the etching treatment, anodizing treatment, etc., to manufacture the aluminum supporting body for lithographic printing plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for roughening an aluminum support used as a support for a lithographic printing plate and a method for producing the same. In particular, aluminum plates that are liable to generate creasing-like streaks called streaks or uneven surface quality called surface unevenness, which are likely to be generated by conventional chemical etching methods, due to the orientation difference of crystal grains. The present invention relates to a method suitable for surface roughening and a method for producing an aluminum support for a lithographic printing plate including the method. Also,
The present invention relates to a method for roughening an aluminum plate capable of uniformly roughening an aluminum plate having a large amount of impurities and poor graining property, and a method for manufacturing an aluminum support for a lithographic printing plate including the method.

[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, and the current is a special alternating waveform current such as a normal sine wave AC or rectangular wave. 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. ,
The print resistance was poor. 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. As the method, there is a roughening method using a special electrolytic power supply waveform (Japanese Unexamined Patent Publication No.
3-67507), and the ratio of the amount of electricity between the anode and the cathode during electrolytic surface roughening using an alternating current (JP-A-54-6560).
No. 7), 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.
No. 6-29699) is known. On the other hand, as a method for manufacturing an aluminum support, an aluminum ingot is melted and held, and a slab (thickness of 400 to 600) is formed.
mm, width 1000-2000mm, length 2000-60
00mm), and after passing through a chamfering step of cutting the impurity structure portion of the slab surface by a chamfering machine at a rate of 3 to 10 mm at a time, a 480-800 mm heat treatment furnace is used to remove stress inside the slab and homogenize the structure. A soaking process is performed at 540 ° C. for 6 to 12 hours, followed by hot rolling at 480 to 5 hours.
Perform at 40 ° C. After rolling to a thickness of 5 to 40 mm by hot rolling, cold rolling is performed at room temperature to a predetermined thickness. 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 uneven surface quality, and differences in the pitting reaction (differences in the number of pits and size) due to crystal orientations appear as streaks and uneven surface quality. appear.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of roughening an aluminum plate for a lithographic printing plate having an improved surface shape which does not cause the above-mentioned failures called streaks and uneven surface quality. An object of the present invention is to provide a method for manufacturing an aluminum support.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an aluminum plate is placed in an aqueous hydrochloric acid solution at a frequency of 50 to 5 frequencies.
A preliminary roughening treatment is performed using an alternating current of 00 Hz with an amount of electricity of 1 to 300 C / dm ² , then a desmutting treatment is performed, and further, an aluminum plate is subjected to an electrochemical roughening treatment. In the method of preliminarily electrochemically roughening in an aqueous solution mainly containing hydrochloric acid and then desmutting in an acidic aqueous solution, it was found that streak hardly occurs in the treatment. The present inventors have found that an efficient desmutting treatment can be performed by performing desmutting treatment while subjecting an aluminum plate to cathodic electrolytic treatment using an auxiliary electrode tank of a sintering apparatus, and thus have accomplished the present invention. That is, the present invention provides a method for roughening aluminum for a lithographic printing plate, which is preliminarily electrochemically roughened in an aqueous solution mainly containing hydrochloric acid and then desmutted in an acidic aqueous solution. A method for roughening an aluminum support for a lithographic printing plate, comprising subjecting an aluminum plate to a desmutting process while subjecting the aluminum plate to a cathode electrolytic treatment using an auxiliary electrode bath of a surface roughening device. The present invention also provides an aluminum plate in order of (1) etching treatment and / or desmutting treatment in an acidic aqueous solution, and (2) 1 to 30 in an aqueous hydrochloric acid solution using an alternating current having a frequency of 50 to 500 Hz.
The surface of the aluminum plate is preliminarily electrochemically roughened with an electric quantity of 0 C / dm ² , (3) the aluminum plate is subjected to cathodic electrolysis treatment in an acidic aqueous solution, and (4) the electrochemical treatment is performed in an acidic aqueous solution. (5) a process of etching the aluminum plate by 0.01 to 5 g / m ² , and / or
Alternatively, there is provided a method for producing an aluminum support for a lithographic printing plate, which comprises performing a desmutting treatment in an acidic aqueous solution and (6) anodizing treatment. In the present invention, in a method of preliminarily electrochemically roughening an aqueous solution mainly containing hydrochloric acid and then desmutting in an acidic aqueous solution, an auxiliary electrode tank of an electrochemically roughening device is used. Preferably, the aluminum plate is desmutted while being subjected to the cathodic electrolytic treatment. In the present invention, it is preferable to use an aqueous solution mainly composed of hydrochloric acid, sulfuric acid, and nitric acid, or a mixed solution thereof as the liquid to be desmutted.
Further, in the present invention, it is preferable that the electrochemical surface roughening in the acidic aqueous solution is performed at an electric quantity of 1 to 800 C / dm ² . In the present invention, mechanical surface roughening treatment before the first step chemical etching treatment,
Alternatively, a more suitable aluminum support for a lithographic printing plate can be obtained by performing a buffing treatment or a buffing treatment and a mechanical roughening treatment. Further, in the present invention, the heat treatment is performed when the temperature of the aluminum plate is 70
It is preferable to carry out at a temperature of from 700C to 700C.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the method of the present invention will be described in detail. In the method of the present invention, the treatment of etching the aluminum plate by 0.01 to 5 g / m ² includes a chemical etching treatment in an acid or alkali aqueous solution,
Electrolytic polishing using an aluminum plate as an anode in an acid or alkali aqueous solution, electrolytic treatment using an aluminum plate as a cathode in a neutral salt aqueous solution, or etching treatment combining two or more of these. If a polishing treatment is performed before the anodization treatment, a more suitable aluminum support for a lithographic printing plate is obtained. In the present invention, it is preferable to perform a hydrophilization treatment after the anodization treatment. In the anodizing treatment, the sulfuric acid concentration is 100 to 200 g / liter, and the aluminum ion concentration in the sulfuric acid aqueous solution is 2 to 10 g / liter.
It is preferable that the anodic oxidation treatment is performed at a liquid temperature of 30 ° C to 40 ° C per liter. Alternatively, it is preferable that the anodic oxidation treatment is performed at a sulfuric acid concentration of 50 to 125 g / liter, an aluminum ion concentration in the aqueous sulfuric acid solution of 2 to 10 g / liter, and a liquid temperature of 40 to 70 ° C.

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 trace amount of the different element may be one or more selected from those described in the periodic table of the element, and 0.001 wt% or more.
It is a support containing 1.5 wt%. Representative examples of the different elements contained in the aluminum alloy include silicon, iron, nickel, manganese, copper, magnesium, chromium, zinc, bismuth, titanium, and vanadium. Conventionally known materials such as those described in the Aluminum Handbook 4th Edition (1990, Light Metal Association), for example, JISA 105
0 material, JIS A 3103 material, JIS A 3005
It is possible to use a material, JIS A1100 material, JIS A 3004 material, or an alloy to which 5 wt% or less of magnesium is added for increasing the tensile strength. In particular, it is suitable for roughening an aluminum plate in which a failure due to the direction of crystal grains occurs. A preferable content ratio of the foreign element in the aluminum alloy is 0.03 to 1.0 wt% of Si.
%, 0.05 to 1.0 wt% of Fe, and 0.001 of Cu
~ 0.2wt%, Ti is 0.01 ~ 0.1wt%, Mn
0 to 1.5 wt%, Mg 0.0 to 0.3 wt%, Z
n is 0 to 0.1 wt%. Particularly preferable content ratio of the foreign element of the aluminum alloy is 0.05 to 0.05% of Si.
0.15 wt%, Fe is 0.1-0.3 wt%, Cu is 0.1-0.02 wt%, Ti is 0.02-0.03 w
t%, Mn is 0.01 to 0.03 wt%, and Mg is 0.0
1-0.03wt%, Zn 0.01-0.02wt%
It is.

[0007] When a large amount of the above-mentioned trace elements is contained, it is difficult to form uniform honeycomb pits by electrochemical surface roughening in an acidic aqueous solution. Also, when a large amount of the Si component is contained, when the anodic oxidation treatment is performed after the surface roughening treatment, the anodic oxide film becomes defective, the water retention of the defective portion is inferior, and the paper is easily stained during printing. When a large amount of Cu component is contained,
The area where no honeycomb pits are formed increases, resulting in an appearance failure. When a large amount of the Si component is contained, the amount of the anodic oxide film is 3 g / m ² -10 when measured by a gravimetric method.
g / m ² is particularly preferred. 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, a twin roller method, a 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, which is susceptible to uneven processing due to a difference in dissolution rate of aluminum due to a difference in crystal grain orientation in alkali etching, is referred to as a streak-like uneven processing called streak or uneven surface quality after alkali etching. This refers to an aluminum plate that is prone to uneven processing. 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 alkali-etched in a sodium hydroxide aqueous solution and desmutted in an acidic aqueous solution in order to dissolve the aluminum plate at 15 g / m ² . AFM on the surface of aluminum plate
When observed in the above, it is suitable for uniformly roughening an aluminum alloy plate in which a step caused by a difference in etching rate is 0.01 μm or more and 0.5 μm or less, more preferably 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 crystal grains long in the rolling direction is about 0.01 mm
The length is 0.5 mm 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 for electrochemical surface roughening using DC or AC or electrolytic polishing or electrolytic treatment of the present invention, 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, the sealing treatment may be performed in boiling water or steam. After the anodizing treatment or the anodizing treatment and the hydrophilic treatment, the photosensitive layer or
By coating and drying the intermediate layer and the photosensitive layer, a PS plate having excellent printing performance can be obtained. 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 surface roughening of an aluminum support for a lithographic printing plate, but also to the surface roughening of any aluminum plate.

Desmut treatment of aluminum plate while performing cathodic electrolytic treatment After preliminary electrochemical surface roughening treatment in an aqueous hydrochloric acid solution, aluminum hydroxide produced by electrochemical surface roughening is mainly used. By removing the smut component described above, electrochemical surface roughening in an acidic aqueous solution to be performed next can be performed more uniformly.
At this time, it is particularly preferable to subject the aluminum plate to a desmut treatment while performing a cathodic electrolytic treatment. A smut component mainly composed of aluminum hydroxide is easily dissolved and dropped off due to a stirring effect of hydrogen gas generated by performing a desmut treatment on the aluminum plate while performing the cathodic electrolytic treatment and a heat generated at an aluminum interface by an electric current. As a device for desmutting an aluminum plate while performing cathodic electrolytic treatment, an electrolytic device may be provided alone,
It is particularly preferred to carry out the cathodic electrolysis using an auxiliary anode bath of a known electrochemical graining device as shown in FIG. This will be described below with reference to FIG. The electrolytic solution is circulated from a circulation tank separate from the main electrolytic cell to the auxiliary anode cell provided with the auxiliary anode. Then, the aluminum plate is subjected to the desmutting process while performing the cathodic electrolytic treatment using the auxiliary anode tank. Lead, iridium oxide, platinum,
Ferrite or the like can be used. The liquid circulating in the auxiliary anode cell may be different from the aqueous solution circulating in the main electrolytic cell used for performing electrochemical surface roughening in at least one of the type, temperature, and composition of the liquid. preferable. As the type of liquid, an acid, alkali or neutral salt aqueous solution can be used, but an acidic aqueous solution is preferably used in view of the stability of the process quality. As the kind of the acidic aqueous solution, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, chromic acid or a mixture of two or more of these can be used. The liquid temperature is selected from the range of 25 to 90 ° C., and the concentration is selected from the range of 0.1 to 40 wt%. The liquid temperature is particularly preferably from 35 to 80 ° C. Aluminum ion may be dissolved in the liquid in an amount of 0 to 10 g / liter, preferably 0.5 to 8 g / liter. The trace elements contained in the aluminum plate are, of course, dissolved in a small amount.

Of the above acidic aqueous solutions, hydrochloric acid, sulfuric acid and nitric acid are particularly preferred. When desmutting the aluminum plate while performing cathodic electrolytic treatment with hydrochloric acid, the concentration of hydrochloric acid is 1 to 100 g / liter, preferably 5 to 75 g / liter.
Use 1 liter of aqueous solution. It is particularly preferable to use iridium oxide or ferrite as the anode facing the aluminum plate. When desmutting the aluminum plate while performing cathodic electrolytic treatment with sulfuric acid, the sulfuric acid concentration is 80 to 400 g / liter, preferably 100 to 400 g / l.
An aqueous solution of 350 g / l is used. It is particularly preferable to use lead, iridium oxide, platinum or ferrite as the anode facing the aluminum plate. When desmutting the aluminum plate while performing cathodic electrolytic treatment using nitric acid, the nitric acid concentration is 5 to 400 g / liter,
Preferably, an aqueous solution of 10 to 350 g / liter is used. It is particularly preferable to use ferrite or platinum as the anode facing the aluminum plate. When the aluminum plate is subjected to the desmut treatment while performing the cathodic electrolytic treatment, a continuous direct current or a pulse direct current is used.
The current density is preferably 1 to 100 A / dm ² at the peak value of the current. The electrolysis time is preferably from 0.1 to 60 seconds, and in continuous processing, from 0.5 to 10 seconds in terms of equipment. When the smut component cannot be completely removed by the desmut treatment during the cathode electrolytic treatment, a known chemical desmut treatment in an aqueous acid or alkali solution can be used as an auxiliary.

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 in 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. 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 45 is used.
At 50 ° C., an aluminum salt is added to an aqueous solution containing 5 to 15 g / liter of hydrochloric acid to make aluminum ions 3 to 50 g.
Particularly preferred is an aqueous solution made up to 1 / liter.

As an additive, an apparatus, a power supply, a current density, a flow rate, and a temperature in an aqueous solution mainly containing hydrochloric acid, those used for known electrochemical surface roughening are used. An aqueous solution is preferred. 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 by electrochemical surface roughening in an aqueous solution mainly containing hydrochloric acid can be selected from a range of 1 to 300 C / dm ² ,
Preferably 150C / dm ^2, since the generated smut or oxide film after to produce fine irregularities in a particularly preferred electrochemical roughening is 10~100C / dm ^2, following electrochemical graining In order to perform the conversion uniformly, it is preferable to perform a mild etching treatment of dissolving the aluminum plate in an acid or alkali aqueous solution in an amount of 0.01 to 5 g / m ² , and 0.01 to 1.
5 g / dm ² is particularly preferred. 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 the unetched portion is uniformly dispersed even if the unetched portion exists. In the preliminary roughening, it is preferable to use an alternating current having a frequency of 50 to 500 Hz, more preferably 50 to 250 Hz, especially 1 to 250 Hz.
It is preferable to use an alternating current of 00 to 250 Hz. Using alternating current with a frequency higher than the commercial frequency, white color,
An aluminum support for a lithographic printing plate excellent in plate inspection properties can be obtained.

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 electrolytic polishing 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 is 0.01 to 0.01 μm. More preferably, chemical etching is performed in an acid or alkali aqueous solution in which 3 g / dm ^{2 is} dissolved.

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, it is preferable to perform draining with a nip roller and washing with water by spraying in order to prevent the treatment liquid from being carried to the next step.
It is more preferable to carry out chemical etching in an acid or alkali aqueous solution in which 0 to 1 g / m ^{2 is} dissolved.

In an aqueous neutral salt solution, place the aluminum plate
Or the electrolytic treatment using a cathode.
And JP-A-59-11295.
Aqueous solution of such salts, including alkali metal halides.
Or alkali metal nitrates such as sodium chloride, nitric acid
Sodium is preferred, especially sodium nitrate
No. The pH is preferably in the range of 5-9, especially 6-8. However
PH 5 or less near the aluminum plate or electrode interface or
It becomes pH 9 or more. The concentration is preferably 1 to 40%. Departure
Electrode facing the aluminum plate used for electrolysis
Therefore, the cathode is made of carbon, stainless steel, and the anode.
Can use platinum, ferrite, iridium oxide, etc.
It is. The aluminum plate as referred to in the present invention is
The current density of direct current used for electrolysis as a pole is 1 to 200 A /
dm ^TwoIs preferred. The electrolysis time is in the range of 0.1 to 90 seconds.
Preferably, it is in the surroundings. Especially the liquid temperature is 35-75 ° C
preferable. Aqueous saline having a pH of 6 to 8, which is particularly advantageous.
In solution, dissolved aluminum ions are hydroxylated
Precipitates in the form of aluminum or aluminum oxide hydrate
From the neutral salt solution by filtration or centrifugation.
It is possible to remove continuously. In aqueous neutral salt solution
Electrolytic treatment using aluminum plate as cathode
When performing the process to dissolve the
Using the auxiliary anode tank shown in Fig. 1 which is used for chemical surface roughening
Is particularly preferred.

Chemical Etching Treatment in Acid or Alkaline Aqueous Solution The concentration of the alkaline aqueous solution is preferably 1 to 30 wt%, and the alloy component contained in the aluminum alloy may be 0 to 10 wt% in addition to aluminum. As the alkaline aqueous solution, an aqueous solution mainly containing caustic soda is particularly preferable. The treatment is preferably performed at a liquid temperature of 30 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, when electrolytic treatment is performed using an aluminum plate as a cathode in a neutral salt aqueous solution, or in an alkaline aqueous solution. In the case of electrolytic polishing, smut is generally formed on the surface of aluminum. In this case, desmutting is performed with phosphoric acid, nitric acid, sulfuric acid, chromic acid, hydrochloric acid, or a mixed acid containing two or more of these acids. The concentration of the acidic aqueous solution is 0.5
~ 60 wt% is preferred. Further, in the acidic aqueous solution, not only aluminum but also 0 to 5% by weight of alloy components contained in the aluminum alloy 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 process, it is preferable to perform draining with a nip roller and washing with water to prevent the treatment liquid from being carried to 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 roller 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. JP-A-6-135175,
The details are described in 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 rolling roller having irregularities to an aluminum plate may be used. Other methods are described in JP-A-55-074898, JP-A-61-162351, JP-A-63-104889, and the like. Aqueous solution mainly composed of nitric acid The aqueous solution mainly composed of nitric acid referred to in the present invention can be used for an electrochemical surface-roughening treatment using ordinary direct current or alternating current. Addition of one or more nitrate ions such as aluminum nitrate, sodium nitrate, ammonium nitrate, etc., and hydrochloric acid or nitrate compound having hydrochloric acid ions such as aluminum chloride, sodium chloride, ammonium chloride, etc. to 1 g / l to saturation. Can be. In an aqueous solution mainly composed of nitric acid, iron, copper,
Metals contained in aluminum alloys such as manganese, nickel, titanium, magnesium and silica may be dissolved. It is particularly preferable to use a solution in which aluminum chloride and aluminum nitrate are added to an aqueous solution of nitric acid of 5 to 20 g / liter so that aluminum ions are 3 to 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 used 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 500 Hz. In the trapezoidal wave, the time tp from the time when the current reaches 0 to the peak is 0.1 to 1
0 msec is preferable, and 0.3 to 2 msec is particularly preferable. Due to the influence of the impedance of the power supply circuit, tp
Is less than 0.1, 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.
If it is longer than 10 msec, it is liable to be affected by trace components in the electrolytic solution, and it is difficult to perform uniform 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, the electric quantity Qc when the aluminum plate is the anode, and the anode It is preferable that the ratio Qc / Qa of the quantity of electricity Qa at the time is in the range of 0.3 to 20 and the anode reaction time ta is 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 2 on both the anode cycle side Ia and the cathode cycle side Ic of the current.
00 A / dm ² is preferred. Ic / Ia is 0.3 to 20
Is preferably within the range. 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 an 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 US-195300 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. 1 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. The electrolytic solution 55 is supplied from the electrolytic solution supply port 54 through the slit 56 to the radial drum roller 52 and the main pole 53a.
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 direct current The electrochemical surface roughening treatment using direct current referred to in the present invention
Is a direct current between the aluminum plate and the electrode facing it.
And electrochemically roughening the surface. Electrolyte
Is a known electrochemical surface roughening method using DC or AC.
What is used for processing can be used. Advantageously,
The aqueous solution mainly containing nitric acid or the water mainly containing hydrochloric acid
It can be selected from a solution or a neutral salt aqueous solution. temperature
Is preferably 10 to 80C. Electrochemical using DC
Use a well-known direct current processing device for surface roughening.
Japanese Patent Application Laid-Open No. 1-141094 can be used.
Alternate pairs of anodes and cathodes as described in
It is preferred to use a side-by-side device. An example of a known device
Japanese Patent Application Laid-Open Nos. 6-328876 and 8-670
No. 78, JP-A-61-19115, JP-B-57-44
No. 760, each publication. Also, aluminum
Conductor roller in contact with the plate
Apply a direct current between the cathode and the aluminum plate
Then, an electrochemical surface roughening treatment may be performed. Electrolytic treatment
After finishing the process, do not bring the processing solution to the next process.
Drain with a nip roller and rinse with spray
It is preferred to do so. Used for electrochemical surface roughening
It is preferable to use a DC current with a ripple rate of 20% or less.
New Current density is 10 to 200 A / dm ^TwoIs preferred,
Electricity when the aluminum plate is the anode is 1-1000C / d
m^TwoIs preferred. Anode is ferrite, iridium oxide
, Platinum, platinum to titanium, niobium, zirconium, etc.
Known, such as clad or plated valve metal
Selected from the oxygen generating electrodes. shadow
The poles are carbon, platinum, titanium, niobium, zirconium,
Select from stainless steel and electrodes used for fuel cell cathodes
Can be used

Heat treatment In the present invention, the heat treatment means that the temperature of the aluminum plate is 7
Heating to 0 ° C. to 700 ° C. to generate an acid or alkali insoluble material on the aluminum surface. When this insoluble material is etched in an acid or alkali aqueous solution, it becomes a resist, and fine irregularities are generated, so that streaks will not be easily seen. The heating time is preferably from 0.01 seconds to 120 minutes. The temperature of the aluminum plate is particularly preferably from 200 to 600 ° C. in the air. As a method for producing insoluble matter, heating in air or an inert gas with the smut component mainly composed of aluminum hydroxide generated by electrochemical graining A method of producing insolubles by heating in pure water with a smut component mainly composed of aluminum hydroxide generated by electrochemical surface roughening treatment attached thereto, It refers to a method of heating in pure water in a state where the smut component mainly composed of aluminum hydroxide generated by the surface treatment is not attached to generate an insoluble matter.

As a heating method, a method of blowing heated gas, a method of heating by wrapping an aluminum web on a heated pass roll, a method of induction heating aluminum, a method of heating in boiling water, a method of using the above in combination, and so on. In addition, a known heating method can be used.

Polishing treatment The polishing treatment referred to in the present invention means a mechanical, electrical, chemical or thermal polishing treatment. Mechanical polishing treatments include abrasive jet spray, water jet spray, magnetic abrasive spray, magnetic polishing, belt grinding, brushing, liquid honing, and the like. There is an ultrasonic method for electric polishing. Thermal polishing includes plasma, electrical discharge machining, and laser machining. Industrially, a mechanical polishing method is preferred, and the aluminum surface is polished using a wheel or roller made of nylon brush, rubber, cloth, non-woven cloth, nylon non-woven cloth, sponge, felt, leather or polishing cloth. Is preferred. The mechanical polishing treatment is preferably a wet type rather than a dry type, since it is less likely to cause a large damage such as an appearance failure. When the wet treatment is performed, it is preferable to perform the treatment while spraying a liquid that acts on water or aluminum or in a liquid that acts on water or aluminum. It is particularly preferable to perform the polishing treatment in combination with an abrasive, whether wet or dry, because the effect of rounding the surface with less energy is high. After the polishing treatment, the aluminum plate is washed with water or treated with an acid or alkali aqueous solution for 0.01 to 0.01 to remove shavings and abrasives.
It is preferable to perform a chemical etching treatment for dissolving 1 g / m ² . Before mechanical polishing, remove the aluminum plate with an acid or alkali aqueous solution for 0.01 mm.
To 30 g / m ^2, particularly preferably it softens the surface of the aluminum plate when 0.1 to 3 g / m ² dissolved, easily mechanical polishing is performed. By mechanical polishing, the convex part of the roughened aluminum support is shaved, the ink is hardly caught by printing and the printed matter is hardly stained, and the sponge is hardly caught when applying dampening water It will be.

The aluminum plate may be rubbed on a flat surface with a nylon brush, sponge, rubber, nonwoven fabric, leather, or the like used for mechanical polishing, or may be rotated using a roller. When a roller is made and rotated, it is preferable that there is a speed difference between the aluminum plate and the outer periphery of the roller. It is preferable that mechanical polishing is performed by using an abrasive having an average particle diameter of 0.001 to 0.1 μm as an auxiliary. Or average diameter, 0.1-5
mm glass or zirconia spheres may be used as an auxiliary. The shape of the abrasive is preferably round and the sharpest possible corners are. The dry or wet type is effective, but the wet type is particularly preferable in that it is hard to be scratched. In the wet method, the liquid cannot have a lubricating action and a cleaning action of shavings, so that the liquid is hardly attached. The liquid is preferably harmless with water, but contains 0 to 10% by weight of aluminum ions and has a concentration of 0.01%.
An acid or alkali aqueous solution of ３０30 wt% may be used. The acid or alkali aqueous solution specifically refers to caustic soda, sulfuric acid, phosphoric acid, and the like. When a liquid containing an abrasive is used, an aqueous solution having a concentration of 0.1 to 50% by weight is preferable. The abrasive is preferably alumina, silica, aluminum hydroxide or the like. The liquid temperature in a wet system can be set at -30 ° C to 90 ° C. Polishing pressure is 0.001 ~
100 kg / cm ² , speed difference from aluminum plate 0.0
The operation is performed at 01 to 100 m / sec. It is particularly preferable that the rotation direction of the roller used for polishing is a combination of a forward direction and a reverse direction with respect to the traveling direction of the aluminum plate. A particularly preferable combination is a method in which rollers used for porosing in the forward direction and the reverse direction are alternately arranged, and one to three rollers are arranged respectively. The particularly preferable rotation speed is 150 to 300 rpm, and the diameter of the roller used for polishing is 300 to 600 mm.

A plurality of polishing wheels, rollers or sections may be combined. When performing a polishing treatment by spraying a liquid of water or an acid or an alkali onto the surface of the aluminum being polished or by immersing an aluminum plate in the liquid, the viscosity of these liquids is preferably 1 to 200 cp, particularly preferably. Is preferably 1.5 to 50 cp. Increasing the viscosity of the liquid makes it easier for a liquid film to form on the aluminum surface,
As a result, the aluminum surface is less likely to be scratched. The method of increasing the viscosity is performed by adding a thickener. It is preferable to use a polymer compound as the thickener. Polyethylene glycol 0.01 to 60
wt%, or 0.01 to 5 wt% of a polymer flocculant used for water treatment and wastewater treatment. The polymer flocculant includes nonionic, anionic and polyacrylic acids. Kurita Water Industries Ltd.
PN-161, PN-162, PN-133, PN-171, PA-328, PA-371, PA-3
22, PA-331, PA-349, PA-372, PA-318, PA-362, PA-363, PA-36
4, PA-365, PA-374, PA-375, PA-376, PA-377, PA-378, PA-37
9, PA-312, LC-541, LC-551 and the like can be used. As a method for increasing the viscosity, a polymer coagulant used for water treatment and wastewater treatment can be used by adding 0.01 to 5% by weight. Nonionic as a polymer flocculant,
There are anionic and polyacrylic acids. As commercial products, PN-161, PN-162, PN-133, PN-171, PA-3 manufactured by Kurita Water Industries Ltd.
28, PA-371, PA-322, PA-331, PA-349, PA-372, PA-318, PA-36
2, PA-363, PA-364, PA-365, PA-374, PA-375, PA-376, PA-37
7, PA-378, PA-379, PA-312, LC-541, LC-551 and the like can be used.

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 5 g / m ² . When the amount is less than 1 g / m ² , the printing durability is insufficient or the non-image portion of the lithographic printing plate is easily scratched, and at the same time, the ink adheres to the wound portion, that is, the so-called scratch stain tends to occur. .
Also, when the amount of the anodic oxide film increases, the oxide film tends to concentrate on the aluminum edge, so that the difference in the amount of the oxide film between the edge and the center of the aluminum plate is 1%.
g / m ² or less. Anodization in a sulfuric acid aqueous solution is described in detail in JP-A-54-128453 and JP-A-48-45303. Preferably, the sulfuric acid concentration is 10 to 300 g / l and the aluminum ion concentration is 1 to 25 g / l. Aluminum sulfate is added to a 50 to 200 g / l aqueous sulfuric acid solution to reduce the aluminum ion concentration to 2-1.
Particularly preferred is 0 g / liter. Liquid temperature is 30
~ 60 ° C is preferred. When using the DC method, the current density is 1
-60 A / dm ² , particularly preferably 5-40 A / dm ² .
When continuously anodizing an aluminum sheet, first perform anodizing at a low current density of 5 to 10 A / dm ² to prevent current concentration called burning of the aluminum plate, and gradually increase the current density toward the latter half. Raise 30
It is particularly preferable to set the current density until the current density reaches 50 A / dm ² or more. Current density is 5-1
It is preferable to gradually increase in five steps. Each step has an independent power supply, and the current density of the power supply is controlled by the current value of the power supply. The power supply method is preferably a liquid power supply method that does not use a conductor roller. 5 and 6
FIG. 1 shows a schematic view of the step of performing anodic oxidation. In order to minimize the power loss, the liquid concentration and temperature of a tank called a power supply tank are usually set to be higher than those of the anodizing tank.
Iridium oxide or lead is used for the electrode of the power supply tank. Aluminum is used for the electrodes of the anodizing tank.

FIG. 5 shows an example of an apparatus for performing an anodic oxidation treatment used in the present invention. In this example, in order to supply electricity to the aluminum plate via the electrolytic solution, a power supply tank was provided with an anodizing tank for forming an anodized film interposed therebetween. FIG.
Is another example of the same apparatus, in which a power supply tank is installed on the upstream side in the traveling direction of the aluminum plate, and an anodizing tank is installed on the downstream side. In these apparatuses, an anode is installed in a power supply tank, and an aluminum plate performs a cathode reaction. Therefore, an anodic oxide film is formed on the surface of the aluminum plate. The distance between the aluminum plate and the cathode is preferably 50 to 200 mm. Aluminum is used for the cathode. The cathode is designed to make it easier for hydrogen gas to escape.
The cathode connected to each DC power supply does not use an electrode having a large area, and it is preferable to divide the cathode into several parts perpendicular to the traveling direction of the aluminum plate. Between the power supply tank and the anodizing tank, there is provided a tank called an intermediate tank in which the electrolyte does not accumulate. By providing the intermediate tank, it is possible to suppress a current that bypasses the anode to the cathode without passing through the aluminum plate. Install a nip roller in the intermediate tank, drain the liquid,
It is preferable to minimize the bypass current. In order to reduce voltage loss in the power supply tank, the temperature of the electrolytic solution is higher or higher than that of the anodizing tank. In the anodizing bath, the composition and temperature of the electrolyte are determined from the formation efficiency of the anodized film, the shape of the micropores of the anodized film, the hardness of the anodized film, the voltage, the cost of the electrolyte, and the like. . In the power supply tank or the anodic oxidation treatment, an electrolytic solution is ejected from a liquid supply nozzle to supply the liquid. In order to keep the distribution of the electrolyte constant and prevent local current concentration on the aluminum plate in the anodizing tank, a slit is provided in the liquid supply nozzle to make the jet flow constant in the width direction. Has become. In the anodizing tank, a shielding plate is provided on the opposite side of the aluminum plate so as to prevent current from flowing on the opposite side to the surface on which the anodized film is to be formed. The distance between the aluminum plate and the shielding plate is preferably 5 to 30 mm.
It is preferable to use a plurality of DC power supplies by connecting the positive side in common. Thereby, the current distribution in the anodizing tank can be controlled.

It is a matter of course that a small amount of a trace element contained in the aluminum plate may be dissolved in the aqueous sulfuric acid solution. Since aluminum is eluted in the sulfuric acid aqueous solution during the anodizing treatment, it is necessary to control the sulfuric acid concentration and the aluminum ion concentration in order to control the process. If the aluminum ion concentration is set low, the sulfuric acid aqueous solution that undergoes anodic oxidation must be renewed frequently, increasing the amount of waste liquid, which is not only economical but also environmentally problematic. Also. When the aluminum ion concentration is set to be high, the electrolysis voltage is increased, the power cost is increased, and it is not economical. The preferred sulfuric acid concentration, aluminum ion concentration and liquid temperature for anodic oxidation are as follows: (1) Sulfuric acid concentration: 100 to 200 g / liter (further 130 to
(180 g / liter) Aluminum ion concentration 2-10 g / liter (further 3-7 g / liter) Liquid temperature 30-40 ° C (further 33-38 ° C) (Part 2) Sulfuric acid concentration 50-125 g / liter (further 80-12)
(0 g / liter) Aluminum ion concentration 2 to 10 g / liter (further 3 to 7 g / liter) The liquid temperature is 40 to 70 (further 50 to 60 ° C.).

After being subjected to anodizing treatment, aluminum
The surface is subjected to a hydrophilic treatment if necessary. Used in the present invention
U.S. Pat. No. 2,714,066 describes a hydrophilic treatment to be performed.
No. 3,181,461, No. 3,280,734 and No. 3
Arca as disclosed in each of the specifications
Li-metal silicate (for example, sodium silicate aqueous solution) method
is there. In this method, the support is sodium silicate aqueous solution.
It is immersed in a solution or electrolytically treated. X-ray fluorescence
0.1 mg / m ^Two-10
0mg / m^TwoIt is preferred that Particularly preferably
1 to 50 mg / m ^TwoRange. In addition, Japanese Patent Publication No. 36-2
Potassium fluoridated zirconate disclosed in Japanese Patent No. 2063
And US Patent Nos. 3,276,868 and 4,153.
Nos. 461 and 4689272.
Such as treatment with polyvinyl phosphonic acid
Is used. In addition, graining treatment and anodizing treatment
It is also preferable to perform a sealing treatment later. Such sealing treatment
Is immersion in hot water and hot aqueous solutions containing inorganic or organic salts.
It is performed by pickling and steam bath.

[0031]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present 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 uneven surface quality 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, mechanical surface roughening is performed by a rotating roller-shaped nylon brush. I did it. 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.
The nylon brush was planted so that holes were made in a stainless steel cylinder having a diameter of 300 mm to make it dense. As the rotating brush, a mechanically roughening treatment was performed by using a brush that rotates forward and a brush that rotates reversely with respect to the traveling direction of the aluminum plate. 0.45μ average surface roughness after mechanical roughening
m.

(2) Etching Treatment in Alkaline Aqueous Solution An aluminum plate was etched by immersing it in an aqueous solution containing 27 wt% of NaOH and 6.5 wt% of aluminum ions at 75 ° C. The dissolution amount of the aluminum plate was 8 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 aqueous hydrochloric acid solution The electrochemical surface-roughening treatment was continuously performed using the AC voltage of FIG. 2 and the apparatus of FIG. 4 in one tank. The electrolyte at this time is
Hydrochloric acid 1wt% aqueous solution (aluminum ion 0.5wt%
), 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 0.3 ms.
c, An electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current having a duty ratio of 1: 1, 60 Hz. 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 50 C / dm ² as the sum of the quantity of electricity when the aluminum plate is the anode.
dm ² . 5 of the current flowing from the power supply is
%. The passage time in the auxiliary electrolytic cell was 2.4 seconds. The electrolytic solution to be supplied to the electrolytic cell provided with the auxiliary anode is as shown in Table 1. In the auxiliary electrolytic cell, the aluminum plate is subjected to desmut treatment while performing cathodic electrolytic treatment. Thereafter, water washing by spraying was performed. (5) Electrochemical surface-roughening treatment in an aqueous nitric acid solution Electrochemical surface-roughening treatment was continuously performed using the AC voltage shown in FIG. 2 and two devices shown in FIG. At this time, the electrolytic solution was a 1 wt% aqueous nitric acid solution (0.5 wt% aluminum ion,
Ammonium ion 0.007 wt%), liquid temperature 50
° C. In the AC power supply waveform, the time TP until the current value reaches a peak from zero is 1 msec, and the duty ratio is 1:
Electrochemical surface roughening treatment was carried out using a trapezoidal rectangular wave alternating current of 1,60 Hz and 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. 5% of the current flowing from the power supply was diverted to the auxiliary anode. afterwards,
Washing with spray was performed.

(6) 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 60 ° C. The dissolution amount of the aluminum plate was 0.6 g / m ² . Thereafter, a water washing treatment was performed. (7) Desmut treatment After that, a water washing treatment was performed, and then a desmut treatment was performed by immersion in an aqueous solution containing 10 wt% of sulfuric acid at 60 ° C. Thereafter, a water washing treatment was performed. (8) Anodizing treatment An aqueous solution having a sulfuric acid concentration of 100 g / liter (containing aluminum ion at 5 g / liter) at a liquid temperature of 55 ° C., and using a DC voltage, a current density of about 5 A / dm ² from 35 A / dm ² to 35 A / dm ^{2. The} current was set so that the current density was increased step by step by ^two , and anodizing treatment was performed so that the amount of anodized film became 2.4 g / m ² . Thereafter, washing with water by spraying was performed. On the surface of this aluminum plate, no streaks or uneven surface quality due to the orientation of crystal grains occurred. The intermediate layer and the photosensitive layer are applied to this aluminum plate and dried, and a positive type P having a dry film thickness of 2.0 g / m ² is formed.
S version was created. When printing using this PS plate,
It was a good printing plate.

[0034]

[Table 1] Example 2 Examples 1-2, 1-3, and 1 shown in Table 1 above.
The substrate after the anodic oxidation treatment of -7 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. 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. When this PS plate was printed, it was a good printing plate. Example 3 For the purpose of hydrophilizing the aluminum substrate after the anodizing treatment in Examples 1-2, 1-3 and 1-7 in Table 1, polyvinylphosphone at 60 ° C. and 0.2% was used. 3 for acid
It was immersed for 0 seconds to perform a hydrophilic treatment. Thereafter, it was washed with water by a spray and dried. When a photosensitive layer was applied to this substrate to form a printing plate, it was a good printing plate. Example 4 After desmutting the aluminum plate in the aqueous solution mainly containing hydrochloric acid in Example 1-3 (4) while performing cathodic electrolytic treatment, the aluminum plate was further placed in an aqueous solution of 25 wt% sulfuric acid at 60 ° C.
Dipped for 0 seconds. Then, it was washed with water. Otherwise, the surface was roughened in exactly the same manner as in Example 1. The intermediate layer and the photosensitive layer were applied to the aluminum plate and dried to prepare a positive PS plate having a dry film thickness of 2.0 g / m ² . When printing was performed using this PS plate, a good printing plate was obtained.

Example 5 Instead of the chemical etching treatment in an alkaline aqueous solution of Example 1-3 (6), a 35 ° C. aqueous solution containing 9 wt% of caustic soda and 0.5 wt% of aluminum ions was used.
A rough surface was prepared in exactly the same manner as in Example 1-2, except that the aluminum plate was used as an anode at a current density of 20 A / dm ² and electrolytic polishing was performed so that the amount of aluminum dissolved was 1 g / m ^2. Treatment. An intermediate layer and a negative photosensitive layer were applied to the treated aluminum plate and dried to prepare a PS plate. When printing was performed using this PS plate, a good printing plate was obtained. Example 7 An aluminum plate to which an aluminum hydroxide-based smut produced by electrochemical surface roughening in an aqueous solution mainly containing nitric acid of Example 1-3 (5) was adhered was heated to a temperature of 200%. Surface roughening treatment was performed in exactly the same manner as in Example 1 except that heat treatment was performed in air at 90 ° C. for 90 minutes. The intermediate layer and the positive photosensitive layer were applied to the treated aluminum plate and dried to prepare a PS plate. When printing was performed using this PS plate, a good printing plate was obtained. Example 8 The substrate before the anodizing treatment in Example 1-3 was subjected to a polishing treatment using an apparatus shown in FIG. 3 in an aqueous solution having a viscosity of 17 cp by adding a polymer coagulant. The intermediate layer and the photosensitive layer were applied to this aluminum plate and dried, and the dried film thickness was 1.
A positive PS plate of ² g / m ² was prepared. When printing was performed using this PS plate, a good printing plate was obtained. In addition, this printing plate was good as a printing plate for proof printing because the sponge that gives the dampening solution was little caught.

Example 9 A roughening treatment was performed in exactly the same manner as in Example 1-3 except that a buffing treatment was performed before the mechanical roughening treatment of Example 1-3 (1). On the surface of this aluminum plate, almost no streak or uneven surface quality due to the crystal grain orientation was generated. The intermediate layer and the photosensitive layer are applied to this aluminum plate and dried, and a positive type P having a dry film thickness of 2.0 g / m ² is formed.
When the S plate was prepared, it was a good printing plate. Example 10 The conditions of the aqueous sulfuric acid solution in the anodic oxidation treatment of Example 1-3 (8) were as shown in Table 2. The amount of the anodic oxide film was adjusted by changing the current density. This aluminum plate did not suffer from burns in the anodic oxidation step due to current concentration.

[0037]

[Table 2] Example 11 The treatment was continuously performed using a JIS 3103 aluminum plate having a thickness of 0.3 mm. (1) Etching Treatment in Alkaline Aqueous Solution An 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 an 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. (2) Desmutting treatment Next, a desmutting treatment was performed by immersing in an aqueous solution containing 1 wt% of hydrochloric acid at 35 ° C. for 5 seconds, and then a water washing treatment was performed. (3) Electrochemical surface-roughening treatment in hydrochloric acid aqueous solution Electrochemical surface-roughening treatment was continuously performed using the AC voltage of FIG. 2 and the apparatus of FIG. 4 in one tank. The electrolyte at this time is
Hydrochloric acid 1wt% aqueous solution (aluminum ion 0.5wt%
), 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 0.3 ms.
c, the duty ratio is 1: 1 and the frequency is 60 Hz (Example 11-1), 120 Hz (Example 11-2), 240H
z (Example 11-3), using a trapezoidal rectangular wave alternating current,
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 50 C / dm ^{2 as} the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power supply was diverted to the auxiliary anode. The passage time in the auxiliary electrolytic cell was 2.4 seconds. The electrolytic solution supplied to the electrolytic cell provided with the auxiliary anode was an aqueous solution having a hydrochloric acid concentration of 50 / liter, an aluminum ion concentration of 4 g / liter and a liquid temperature of 40 ° C. In the auxiliary electrolytic cell, desmutting is performed while the aluminum plate is subjected to cathodic electrolytic treatment. Thereafter, washing with water by spraying was performed.

(4) Electrochemical surface-roughening treatment in an aqueous nitric acid solution Electrochemical surface-roughening treatment was continuously performed using the AC voltage shown in FIG. 2 and two devices shown in FIG. At this time, the electrolytic solution was a 1 wt% aqueous nitric acid solution (0.5 wt% aluminum ion,
Ammonium ion 0.007 wt%), liquid temperature 50
° C. The AC power supply waveform is electrochemical surface roughening using a carbon electrode as a counter electrode using a trapezoidal rectangular wave AC with a time TP from a current value of zero to a peak reaching 0.8 msec, a duty ratio of 1: 1, 60 Hz, and a trapezoidal wave. Processed. 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, washing with water by spraying was performed. (5) Etching treatment in alkaline aqueous solution The aluminum plate was etched by immersing the aluminum plate in an aqueous solution containing 5 wt% of NaOH and 0.5 wt% of aluminum ions at 40 ° C. The dissolution amount of the aluminum plate was 0.1 g / m ² . Thereafter, a water washing treatment was performed. (6) Desmut treatment Next, sulfuric acid 25 wt% (aluminum ion 0.5 wt%)
Immersion in an aqueous solution at 60 ° C. for 5 seconds to perform desmut treatment. Thereafter, a water washing treatment was performed. (7) Anodizing treatment A sulfuric acid concentration of 150 g / liter aqueous solution (aluminum ion: 5 g / liter) at a liquid temperature of 35 ° C., and a current density of 2 A / liter
Using a direct current of dm ² , the anodic oxide film amount was 2.4 g /
Anodizing treatment was performed so as to obtain m ² . afterwards,
Washing with spray was performed. The surface quality of this aluminum plate was good. The intermediate layer and the photosensitive layer were applied to this aluminum plate and dried to form a positive PS plate having a dry film thickness of 2.0 g / m ² , which was a good printing plate.

Example 12 For the purpose of hydrophilization, the substrate after the anodizing treatment of Example 11-1 was immersed in an aqueous solution of sodium silicate (2.5 wt%) at 70 ° C. for 14 seconds, and then washed with a spray. Dried. 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. When this PS plate was printed, it was a good printing plate. Example 13 A roughening treatment was performed in exactly the same manner as in Example 11-1, except that a buffing treatment was performed before the chemical etching treatment in Example 11-1 (1). The surface quality of this aluminum plate was good. The intermediate layer and the photosensitive layer were applied to this aluminum plate and dried to form a positive PS plate having a dry film thickness of 2.0 g / m ² , which was a good printing plate. Example 14 The amount of electricity in the preliminary electrochemical surface-roughening treatment in an aqueous hydrochloric acid solution of Example 11-3 (3) was determined to be 25 C / dm ^{2 in} total when the aluminum plate was an anode (Example 14- 1), 100
The processing was performed in exactly the same manner as in Example 12-3, except that C / dm ² (Example 14-2) and 300 C / dm ² (Example 14-3). The surface quality of this aluminum plate was good.
The intermediate layer and the photosensitive layer were applied to this aluminum plate and dried to form a positive PS plate having a dry film thickness of 2.0 g / m ² , which was a good printing plate. Example 15 The substrate subjected to the anodizing treatment in Example 11-1 was subjected to a hydrophilic treatment by immersing the substrate in 0.2% polyvinylphosphonic acid at 60 ° C. for 30 seconds for the purpose of hydrophilic treatment. Thereafter, it was washed with water by a spray and dried. When a photosensitive layer was applied to this substrate to form a printing plate, it was a good printing plate.

[0040]

According to the present invention, there is provided at low cost an aluminum support for a lithographic printing plate, in which processing unevenness due to a difference in aluminum dissolution rate due to a difference in crystal grain orientation called a streak or surface quality unevenness does not easily occur. can do. Also,
It is possible to provide an aluminum support for a lithographic printing plate, which is unlikely to cause processing unevenness generated by electrochemical surface treatment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an electrolysis device used for electrochemical graining of the present invention.

FIG. 2 is a waveform diagram showing an example of a trapezoidal countercurrent power supply waveform used for electrochemical graining of the present invention.

FIG. 3 is a schematic diagram illustrating an example of an apparatus that performs a polishing process according to the present invention.

FIG. 4 is a schematic view showing an example of an electrolysis device used for electrochemical graining of the present invention.

FIG. 5 is a schematic view showing an example of an apparatus used for performing an electrolytic oxidation treatment in the present invention.

FIG. 6 is a schematic view showing another example of an apparatus used for performing the electrolytic oxidation treatment in the present invention.

[Explanation of symbols]

Reference Signs List 50 main electrolytic cell 51 radial drum roller 53a, 53b main electrode 55 electrolytic solution 56 auxiliary anode 60 auxiliary anode tank W aluminum plate ta anode reaction time tb cathode reaction time tc time from current 0 to peak Ia anode cycle side Peak current Ic Peak current on the cathode cycle side

Claims (13)

[Claims] In a method for roughening aluminum for a lithographic printing plate, which is preliminarily electrochemically roughened in an aqueous solution mainly composed of hydrochloric acid and then desmutted in an acidic aqueous solution, the electrochemical roughening method is performed. A method for roughening an aluminum support for a lithographic printing plate, comprising subjecting an aluminum plate to a desmutting process while subjecting the aluminum plate to a cathodic electrolytic treatment using an auxiliary electrode tank of a surfacer. 2. An acidic aqueous solution for subjecting an aluminum plate to desmut treatment while subjecting an aluminum plate to cathodic electrolytic treatment using an auxiliary electrode bath of an electrochemical graining device is an aqueous solution mainly containing hydrochloric acid, sulfuric acid, or nitric acid, or The method for roughening an aluminum support for a lithographic printing plate according to claim 1, wherein the mixture is a mixed solution of: 3. An aluminum plate is sequentially subjected to (1) etching treatment and / or desmut treatment in an acidic aqueous solution, and (2) 1 to 300 C / dm ^{2 in an} aqueous hydrochloric acid solution using an alternating current having a frequency of 50 to 500 Hz. (3) Desmut treatment while cathodic electrolytic treatment of aluminum plate in acidic aqueous solution, (4) Electrochemical roughening in acidic aqueous solution Process,
(5) An aluminum support for a lithographic printing plate, characterized by subjecting the aluminum plate to etching of 0.01 to 5 g / m ² and / or desmutting in an acidic aqueous solution, and (6) anodizing. Manufacturing method. 4. An acidic aqueous solution for desmutting an aluminum plate while performing cathodic electrolytic treatment on an aluminum plate using an auxiliary electrode bath of an electrochemical surface roughening device is an aqueous solution mainly containing hydrochloric acid, sulfuric acid, or nitric acid, or 4. The method for producing an aluminum support for a lithographic printing plate according to claim 3, wherein the mixture is a mixture of the following. 5. The method according to claim 1, wherein a mechanical roughening process, a buff polishing process, or a buff polishing process and a mechanical roughening process are performed before the chemical etching process in the first step. A method for producing an aluminum support for a lithographic printing plate according to claim 3. 6. The method according to claim 3, wherein after the electrochemical surface-roughening treatment in the acidic aqueous solution, a heat treatment is performed so that the temperature of the aluminum plate becomes 70 ° C. to 700 ° C. 5. The method for producing an aluminum support for a lithographic printing plate according to any one of the above items 5. 7. An aluminum plate of 0.01 to 5 g / m ^2.
Chemical etching in an acid or alkali aqueous solution, electrolytic polishing using an aluminum plate as an anode in an acid or alkali aqueous solution, or electrolytic treatment using an aluminum plate as a cathode in a neutral salt aqueous solution The method for producing an aluminum support for a lithographic printing plate according to any one of claims 3 to 6, wherein: 8. The method for producing an aluminum support for a lithographic printing plate according to claim 3, wherein a polishing treatment is performed before the anodic oxidation treatment. 9. The method for producing an aluminum support for a lithographic printing plate according to claim 3, wherein a hydrophilization treatment is performed after the anodic oxidation treatment. 10. An aluminum plate roughened by the method of claim 1 or 2, wherein the aluminum plate has a sulfuric acid concentration of 100 to 20.
0 g / liter, the concentration of aluminum ions contained in the aqueous sulfuric acid solution is 2 to 10 g / liter, and the liquid temperature is 30 ° C to 40 ° C.
A method for producing an aluminum support for a lithographic printing plate, comprising subjecting the aluminum support to anodic oxidation at a temperature of ° C. 11. An anodic oxidation treatment wherein the sulfuric acid concentration is 100 to 2
00 g / liter, the concentration of aluminum ions contained in the aqueous sulfuric acid solution is 2 to 10 g / liter, and the liquid temperature is 30 ° C to 4 ° C.
The method for producing an aluminum support for a lithographic printing plate according to claim 3, wherein the anodic oxidation treatment is performed at 0 ° C. 12. The aluminum plate roughened by the surface roughening method according to claim 1 or 2 having a sulfuric acid concentration of 50 to 125.
g / liter, the concentration of aluminum ions contained in the aqueous sulfuric acid solution is 2 to 10 g / liter, and the liquid temperature is 40 ° C to 70 ° C.
A method for producing an aluminum support for a lithographic printing plate, comprising subjecting the aluminum support to anodic oxidation. 13. An anodic oxidation treatment wherein the sulfuric acid concentration is 50 to 125.
g / liter, the concentration of aluminum ions contained in the aqueous sulfuric acid solution is 2 to 10 g / liter, and the liquid temperature is 40 ° C to 70 ° C.
4. The method for producing an aluminum support for a lithographic printing plate according to claim 3, wherein the anodic oxidation treatment is performed.