JPH06328876A - Device and method for manufacturing aluminum base for lithographic printing block and aluminum base for lithographic printing block - Google Patents

Abstract

PURPOSE:To uniformly roughen the surface of an aluminum base employed for offset printing block or the like. CONSTITUTION:Acidic aqueous solution 2 is stored in an electrolytic bath 1, on the bottom of which a plurality of anodes 5 and cathodes 6 having the same form are alternately arranged through partition walls having the same length. Each pair of the anode 5 and the cathode 6 are connected to each other through a DC power source. Near both the ends of the electrolytic bath 1, carrier rollers 8 are immersed half in the acid water solution 2. An aluminum plate 9 can be moved in the acidic aqueous solution 2 under the state of being supported between the carrier rollers 8. When the running speed (v) of the aluminum plate 9 is assumed to be v=V(m/sec), the respective lengths L(m) of the anode and 5 of the cathode 6 are set to be within the range of L=0.05V-5V.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for producing a roughened aluminum support for printing plates suitable for offset printing plates and the like, and an aluminum support for printing plates.

[0002]

2. Description of the Related Art Conventionally, an aluminum plate has been widely used as a support for a lithographic printing plate, but it has good adhesion to a photosensitive layer provided thereon and a lithographic plate prepared by using the same. Improving the water retention of the non-image area of the printing plate (the area that receives the dampening water used during printing and repels the oil-based ink, and the area where the surface of the support is exposed plays the role). For the purpose of, the surface of the aluminum plate is usually roughened.

This roughening treatment is called so-called graining and is an indispensable step in the preparation of the lithographic printing plate support, and is a work which requires a considerable degree of skill.
This graining is roughly classified into mechanical graining methods such as ball grain, wire grain and brush grain, and electrochemical graining methods.

In the case of a ball grain, the material of the ball,
There are many factors that require skill, such as the type of polishing agent and the adjustment of water content during polishing, and it is not possible to perform the work continuously, and it is necessary to finish each one. In addition, the wire grain has non-uniform grain. On the other hand, brush grain is an improved version of these methods, and it is suitable for mass production because it has a uniform grain and can be continuously treated.

However, it is difficult to obtain sufficient performance as a printing plate support by the above mechanical method.

It is generally said that a large surface roughness improves water retention (that is, water retention), and when preparing a lithographic printing plate for the purpose of improving water retention or facilitating printing, It is said that the surface shape of the support preferably has unevenness as uniform as possible. As a method for obtaining such a preferable surface shape, an electrochemical roughening method has been attracting attention.

According to this method, the composition of the electrolytic solution,
By keeping various conditions such as temperature and electrolysis conditions constant,
An aluminum plate with a roughened surface is obtained.

Electrochemical surface roughening methods are roughly classified into a method using alternating current and a method using direct current. The method using an alternating current has a drawback in that a process unevenness corresponding to the frequency of the alternating current used for electrochemical surface roughening and the traveling speed of the aluminum plate is likely to occur in a direction perpendicular to the method of moving the aluminum plate.

According to a method for solving this drawback, electrodes facing the aluminum plate are alternately arranged with an anode and a cathode, and a DC voltage is applied between these electrodes so that the aluminum support is separated from these electrodes at an arbitrary distance. There has been proposed a surface roughening method that allows the surface to pass through while maintaining the passage (JP-A-1-141094 (USP)).
Corresponding to No. 4902389).

[0010]

However, in the above-described roughening method of applying a DC voltage, it is not possible to sufficiently form uniform honeycomb pits on an aluminum plate.

The present invention solves the above-mentioned drawbacks and provides an apparatus for manufacturing an aluminum support for a lithographic printing plate capable of forming a uniform rough surface honeycomb pit, and an aluminum support for a lithographic printing plate capable of forming a honeycomb pit having an arbitrary diameter. It is an object to provide a manufacturing method and an aluminum support for a lithographic printing plate.

[0012]

Means and Actions for Solving the Problems
In order to achieve the above object, the size and shape of the anode and cathode,
When the arrangement form, etc. are studied carefully, and when the length of the anode (cathode) in the aluminum plate direction and the traveling speed of the aluminum plate have a specific relationship, they penetrate the acidic aqueous solution of the aluminum plate before reaching the first electrode. It was found that uniform honeycomb pits can be made when the aluminum nitrate and ammonium nitrate concentrations in the acidic aqueous solution are specific, and the length of the anode (cathode) and the traveling speed of the aluminum plate are adjusted. It was found that a honeycomb pit having an arbitrary diameter can be produced by performing the above-mentioned method, and at least one of mechanical surface roughening, chemical etching and electrochemical surface roughening, and an electric current using direct current are used. It was found that a good printing plate can be formed by combining with chemical surface roughening, and furthermore, as a printing plate, good honeycomb pit formation can be achieved. Heading the state, one in which the present invention has been completed.

That is, at least one apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention is provided.
Two electrolytic cells and an acidic aqueous solution stored in this electrolytic cell,
The anode and the cathode alternately arranged in the acidic aqueous solution and supplied with a DC voltage, and the transport roller arranged so that the aluminum plate travels in the acidic aqueous solution, the aluminum plate of each of the anode and the cathode. The length L [m] in the traveling direction of the aluminum plate is V [m / se]
c] is 0.05 V to 5 V [m].

The apparatus for manufacturing an aluminum support for a lithographic printing plate according to the second aspect of the present invention has at least one electrolytic bath, an acidic aqueous solution stored in the electrolytic bath, and alternating arrangements in the acidic aqueous solution. An aluminum plate having an anode and a cathode to which a DC voltage is supplied and a transport roller arranged so that the aluminum plate travels in an acidic aqueous solution, and the traveling speed of the aluminum plate is V [m / sec]. From the position of the boundary line between the aluminum plate and the acidic aqueous solution when the aluminum plate penetrates into the acidic aqueous solution to the position opposite to the end of the electrode that carries out the first electrolytic reaction of the invading aluminum plate on the anti-aluminum plate running direction side. The plate is characterized by having a length of 0 to 5 V [m].

An apparatus for manufacturing an aluminum support for a lithographic printing plate according to a third aspect of the present invention has at least one electrolytic bath, an acidic aqueous solution stored in the electrolytic bath, and alternating arrangements in the acidic aqueous solution. It has an anode and a cathode to which a direct current voltage is supplied, and a transport roller arranged so that an aluminum plate travels in an acidic aqueous solution, and the acidic aqueous solution contains 20 g / l of aluminum nitrate to saturation and 0.1 mg of ammonium nitrate. It is characterized by being from g / l to saturation.

In the method for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention, at least one electrolytic bath, an acidic aqueous solution stored in the electrolytic bath, and the acidic aqueous solution are alternately arranged. Using an apparatus having an anode and a cathode to which a DC voltage is supplied and a transport roller arranged so that an aluminum plate travels in an acidic aqueous solution, and causing the aluminum plate to perform an anode reaction or a cathode reaction at least three times or more. Is configured.

In the method for producing an aluminum support for a lithographic printing plate according to the second aspect of the present invention, the surface of an aluminum plate is sequentially subjected to (a) chemical etching treatment in an acid or alkali aqueous solution, (b). Using the manufacturing equipment described above, 0.1
Electrochemically roughening with ~ 5V length anode and cathode,
(c) A chemical etching treatment with an acid or alkali aqueous solution, (d) an electrochemical roughening treatment with an anode and a cathode having a length of 0.05 to 3 V using the above-mentioned manufacturing apparatus, (e) It is characterized in that it is chemically etched in an acid or alkali aqueous solution.

In the method for producing an aluminum support for a lithographic printing plate according to the third aspect of the present invention, the surface of the aluminum plate is chemically etched in (a) an acid or alkaline aqueous solution, and (b). Using the manufacturing equipment described above, 0.1
Electrochemically roughening with ~ 5V length anode and cathode,
(c) Chemically etching with an acid or alkaline aqueous solution, (d) Electrochemical surface roughening with an alternating current in an acidic aqueous solution, and (e) Chemically etching in an acidic or alkaline aqueous solution. It is configured to do.

In the method for producing an aluminum support for a lithographic printing plate according to the fourth aspect of the present invention, the surface of the aluminum plate is (a) mechanically roughened, or in an acid or alkali aqueous solution. Electrochemical surface roughening treatment using alternating current after chemical etching treatment in (b) Chemical etching treatment in acid or alkali aqueous solution, (c) 0.05 ~ It is characterized in that an anode and a cathode having a length of 3 V are electrochemically surface-roughened, and (d) a chemical etching treatment is carried out in an acid or alkali aqueous solution.

The aluminum support for a lithographic printing plate of the present invention has irregularities having an average pitch of 1 to 20 μm and an average of 0.05 to 2 μm.
The pitch irregularities are formed to overlap each other, and the average surface roughness is 0.3 to 1.5 μm.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention, the length L of the anode and cathode in the traveling direction of the aluminum plate is the traveling speed of the aluminum plate being V [m / sec]. ], L = 0.05V to 5
It is set in the range of V [m]. The length L [m] of the anode and the cathode in the traveling direction of the aluminum plate is less than 0.05 V [m], which is the length of the portion that is substantially parallel to the aluminum plate and is immersed in the acidic aqueous solution. If so, the honeycomb pits tend to be non-uniformly formed, and stable roughening becomes difficult. If it is higher than 5 V [m], the honeycomb pits become too large and the surface is not suitable for an aluminum support for lithographic printing plates.

In the apparatus for producing an aluminum support for a lithographic printing plate according to the second aspect of the present invention, when the traveling speed of the aluminum plate is V [m / sec], the aluminum plate when it penetrates into the acidic aqueous solution is used. Of the aluminum plate from the position of the boundary line with the acidic aqueous solution to the position facing the end of the invading aluminum plate on the anti-aluminum plate running direction side of the electrode for performing the first electrolytic reaction H [m]
Is set to 0 to 5 V [m].

The length H of the aluminum plate is the length from when the aluminum plate penetrates the acidic aqueous solution to when it reaches the first electrode. In the case of the vertical cell, the length from the liquid surface to the electrode. And for a flat cell,
It is the length from the position where the aluminum plate penetrates the acidic aqueous solution to the electrode through the transport roller, and in the case of a radial type cell, the straight line or straight line and circle from the position where the aluminum plate penetrates the acidic aqueous solution to the electrode. It is the length combined with the arc shape. The length H of such an aluminum plate
However, if it is larger than 5 V [m], a non-uniform roughened surface is formed and good performance cannot be obtained when used as a printing plate.

To adjust the length H of the aluminum plate, for example, a vertically movable dam plate is provided on the side wall of the electrolytic cell,
By adjusting the vertical position of the weir plate, the height of the liquid surface of the acidic aqueous solution can be changed, or the position of the drainage port of the electrolytic cell can be changed by moving the electrode ( (For vertical cells, move vertically, for flat cells, move horizontally, and for radial cells, move circumferentially).

The apparatus for producing an aluminum support for a lithographic printing plate according to the second aspect is preferable to the apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect in terms of ease of adjustment. That is, when the traveling speed of aluminum is constant, in the manufacturing apparatus of the second aspect, the length H of the aluminum plate can be easily adjusted by changing the height of the acidic aqueous solution, but in the manufacturing apparatus of the first aspect, , The length of the electrode itself must be changed. Further, by combining the apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect and the second aspect, more delicate adjustment can be performed.

In the apparatus for producing an aluminum support for a lithographic printing plate according to the third aspect of the present invention, at least one electrolytic cell, an acidic aqueous solution stored in this electrolytic cell, and a DC solution alternately disposed in the acidic aqueous solution. It has an anode and a cathode to which a voltage is supplied, and a transport roller arranged so that an aluminum plate travels in an acidic aqueous solution. The acidic aqueous solution is 20 g / l to saturated aluminum nitrate and 0.1 g ammonium nitrate. / L to saturation.

The amount of aluminum nitrate in the acidic aqueous solution is
It is 20 g / l or more, preferably 50 g / l or more, and when aluminum nitrate is less than 20 g / l, the uneven surface tends to be uneven. Further, the amount of ammonium nitrate in the acidic aqueous solution is 0.1 g / l or more, preferably 0.3 g / l or more, and when the ammonium nitrate is less than 0.1 g / l, the honeycomb pits are concentrated when the amount of electricity is large. It tends to become a uniform rough surface.

Items common to the apparatus for manufacturing an aluminum support for a lithographic printing plate according to each aspect of the present invention will be described below.

To place the anode and cathode in the electrolytic cell, 1
Even if all or a plurality of anodes and cathodes are arranged in one or more electrolytic cells, the electrolytic cells are provided by the number of pairs of anode and cathode, and even if a pair of anode and cathode is arranged in each electrolytic cell, It is also possible to provide twice as many electrolytic cells as the number of pairs of cathodes, and to separately arrange the anode and the cathode in each electrolytic cell. Length L of an anode or a cathode when a plurality of anodes and cathodes are arranged in the above-mentioned one electrolytic cell
Is the length at a pair of anode and cathode.

When at least one pair of anode and cathode is arranged in one electrolytic cell, a partition is provided between the anode and the cathode for the purpose of suppressing the bypass current flowing directly from the anode to the cathode without using the aluminum plate. A wall can be provided. The partition wall preferably has a height of about 20 to 80% of the distance between the aluminum plate and the anode or cathode facing the aluminum plate, and is preferably provided over the entire gap between the anode and the cathode. The partition wall preferably has electrical insulation and chemical resistance, and vinyl chloride, FRP, rubber, Teflon or the like can be used. Partition walls may be provided on both sides of the electrode not only for suppressing the bypass current but also for reducing the spread of the potential distribution between the electrode and the aluminum plate.

The anode and the cathode may be arranged horizontally or may be arranged vertically suspended by using an anode case as disclosed in Japanese Patent Laid-Open No. 4-268097.
When the anode and the cathode are arranged horizontally, they may be on the upper surface side or the lower surface side of the aluminum plate.

The alternating arrangement of the anode and the cathode may be such that the anode is arranged at the head or the cathode is arranged at the head in the traveling direction of the aluminum plate. It is preferred to start the process with the cathode first and the anodic reaction of the aluminum plate.

The anode and the cathode may be composed of a single member or a combination of a plurality of electrode pieces, and can be manufactured easily and inexpensively, and the current distribution can be made uniform. It is preferable to be configured by combining. In the case of manufacturing a plurality of electrode pieces in combination, for example, the plurality of electrode pieces are arranged in parallel at a predetermined interval, or the plurality of electrode pieces are arranged in parallel via an insulator of about 1 to 5 mm. The shape of such an electrode piece is not particularly limited,
The shape may be rectangular or round. As the insulator, a material having both electric insulation and chemical resistance is preferable, and vinyl chloride, rubber, Teflon, FRP or the like is used.

The respective anodes may have the same length or different lengths, and the respective cathodes may have the same length or different lengths. The distance between the anode and the cathode may be the same or different, but is preferably 50 mm or more, more preferably 150 mm or more.
Further, the lengths of the anode and the cathode may be stepwise lengthened or stepwise shortened with respect to the traveling direction of the aluminum plate. Furthermore, the pair of anode and cathode may have different lengths. The distance between the anode or cathode and the aluminum plate is
It is preferably about 5 to 20 mm.

As the anode, an electrode formed by plating or clad with a platinum group metal such as platinum on a valve metal such as titanium, tantalum or niobium, or a ferrite electrode can be used.

For the cathode, stainless steel, carbon or platinum, titanium, tantalum, niobium, zirconium,
Hafnium or an alloy thereof can be used, and the surface of the cathode is preferably 0.8-S or less, more preferably 0.4-S or less. Surface finishing of 0.8-S or less can be performed by cold rolling, lapping, surface grinding, face milling, paper finishing, buffing, electrolytic polishing, chemical polishing, liquid honing and the like. In the usual method, copper or aluminum is used for the core material of these anodes or cathodes in order to improve conductivity.

The aluminum plate includes a pure aluminum plate and an aluminum alloy plate, and the manufacturing method thereof is not particularly limited. Various aluminum alloys can be used, for example, silicon, copper, manganese, magnesium, chromium, lead, zinc, bismuth, titanium, tantalum,
An alloy of aluminum with a metal such as niobium, iron or nickel can be used.

The aluminum plate may be roughened on only one side or may be roughened on both sides. When only one side is roughened, either side of the aluminum plate may be roughened, and when both sides are roughened, one side may be successively roughened or both sides may be roughened. At the same time, roughening treatment may be performed.

The electrolytic cell used in the present invention is as follows.
A radial type electrolytic cell as disclosed in JP-A-141109 or the like may be used, or a flat type electrolytic treatment tank as disclosed in JP-A-1-141094 may be used.
Flat type electrolytic treatment tank can be placed vertically or horizontally
It may be placed diagonally.

The electrolytic cell is usually provided with a liquid supply port for supplying at least one acidic aqueous solution and a waste liquid port for discharging the acidic aqueous solution. The liquid supply port and the waste liquid port are provided at arbitrary positions in the electrolytic cell, and as required, as disclosed in JP-A-2-240300, a plurality of liquid supply ports and waste liquid ports can be provided.

The acidic aqueous solution used in the present invention may be one used for electrochemical surface roughening treatment using an alternating current, but an aqueous solution mainly containing hydrochloric acid or nitric acid is preferable, and an aqueous solution mainly containing nitric acid is preferable. Is more preferable. A metal contained in an aluminum alloy such as aluminum, iron, copper, manganese, nickel, titanium, magnesium, or silica may be dissolved in the acidic aqueous solution. Further, ammonium ions, sulfate ions, etc. may be added.

The aqueous solution containing nitric acid as a main component (hereinafter referred to as nitric acid aqueous solution) preferably has a nitric acid compound concentration of about 0.1 g / l to a saturation limit, more preferably about 0.1 to about 100 g / l. The nitric acid compound is preferably aluminum nitrate, sodium nitrate, ammonium nitrate, etc., and one or more of them can be used. Also,
Other compounds containing other nitrate ions can also be used in combination. More preferably, one or more of the aluminum and ammonium salts are mixed in an amount of about 0.1 to about 100 g / l. The ammonium ion spontaneously increases by electrolytic treatment in a nitric acid aqueous solution.

The components contained in the aluminum ion or aluminum alloy material increase with the electrolytic reaction. If necessary, a nitric acid compound is added, or water and nitric acid are added to maintain a constant value.

The temperature of the aqueous nitric acid solution is preferably in the range of about 30 to about 55 ° C. Further, the average flow rate of the acidic aqueous solution in the electrolytic cell is preferably in the range of about 50 to about 500 cm / sec. The flowing direction of the acidic aqueous solution may be the same as or opposite to the traveling direction of the aluminum plate, and may be the same or different for each electrolytic cell.

The traveling speed of the aluminum plate is 1 to 300 m /
The speed fluctuation rate is preferably 1% or less, and the speed fluctuation cycle is preferably 0.1 Hz or less.

The DC voltage in the present invention refers to a voltage whose polarity does not change. Examples of the DC voltage include continuous DC voltage, commercial AC rectified by a diode, transistor, thyristor, GTO, and rectangular pulse DC voltage. Ripple ratio can be roughened from 0 to 100%, but
A continuous DC voltage having a ripple rate of 30% or less is particularly preferable.

The current density is preferably about 20 to about 200 A / dm ² , and more preferably about 50 to about 120 A / dm ² . The current density may be the same or different for each electrode or each electrolytic cell. The amount of electricity applied to the aluminum plate is about 50 ~
About 1000 C / dm ² is preferred and about 10 to about 800 C / dm ² is more preferred.

The DC voltage may be supplied from a single power supply device to a plurality of anodes and cathodes, or may be supplied separately for each pair of anodes and cathodes. Further, a plurality of apparatuses for manufacturing the aluminum support for a lithographic printing plate of the present invention may be provided and the surface roughening treatment may be performed several times.

Before and after the surface roughening treatment using a DC voltage by the production apparatus of the present invention, mechanical surface roughening treatment, chemical desmutting treatment and etching treatment in an acid or alkali aqueous solution, neutral salt aqueous solution. Electrochemical etching treatment in water, electrochemical roughening treatment using alternating current in nitric acid-based aqueous solution, electrochemical roughening treatment using alternating current in hydrochloric acid-based aqueous solution It is possible to perform a surface treatment, an electrochemical surface roughening treatment in a neutral salt aqueous solution, and the like. These processes can be performed by combining two or more.
Further, a water washing treatment can be interposed between these treatments.

As a preferable manufacturing method using the apparatus for manufacturing an aluminum support for a lithographic printing plate of the present invention, there is a method for manufacturing an aluminum support for a lithographic printing plate according to the first to fourth aspects of the present invention.

In the method for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention, the aluminum plate is subjected to the anode reaction or the cathode reaction at least three times or more.

In the method for producing an aluminum support for a lithographic printing plate according to the second aspect of the present invention, the production apparatus of the present invention is used.
Electrochemically roughening the surface with an anode and a cathode having a length of 0.1 to 5 V and using the manufacturing apparatus of the present invention through etching treatment.
Electrochemical graining is performed with an anode and a cathode having a length of 0.05 to 3V. In the first surface roughening treatment, if the length of the anode and the cathode is less than 0.1 V, the pit diameter becomes too small, and the surface roughening treatment of the first stage is stable and has a large surface roughness. It becomes difficult to make a surface. On the other hand, if it exceeds 5 V, the honeycomb pits become too large and the surface is not suitable for an aluminum support for lithographic printing plates. In the first roughening treatment, it is preferable to obtain a rough surface having a uniform end-etched portion and large-diameter honeycomb pits. In the second roughening treatment, if the length of the anode and the cathode is less than 0.05 V, the generation of honeycomb pits tends to be non-uniform, and stable roughening becomes difficult. Also, 3
When it exceeds V, the pit diameter of the honeycomb pit becomes too large, and it is not suitable as the honeycomb pit generated in the second roughening treatment.

According to this manufacturing method, since mechanical roughening is not performed, the flatness of the aluminum plate is good, and the DC power source is used, so that the equipment cost can be reduced as compared with the method using the AC power source. Further, since a double-structured surface having a uniform large-wave structure can be obtained, it is possible to achieve a high level of balance between stain on the blank, difficulty in entanglement of ink, and printing durability.

In the method for producing an aluminum support for a lithographic printing plate according to the third aspect of the present invention, the production apparatus of the present invention is used.
Electrochemical surface roughening treatment is performed with an anode and a cathode having a length of 0.1 to 5V, and then etching treatment and electrochemical surface roughening treatment using alternating current are performed. Anode and cathode length is 0.
If it is less than 1 V, the pit diameter becomes too small, and it becomes difficult to stably form a rough surface having a large surface roughness as the first roughening treatment. On the other hand, if it exceeds 5 V, the honeycomb pits become too large, and the surface is not suitable for an aluminum support for flat printing plates. In the first roughening treatment, it is preferable to obtain a rough surface having a uniform unetched portion and large-diameter honeycomb pits.

According to this manufacturing method, since mechanical surface roughening is not performed, it is possible to obtain an aluminum support for a lithographic printing plate which has a good flatness of an aluminum plate. In addition, since a double-structured surface having a uniform large wave structure is obtained, it is possible to balance the stain on the blank, the difficulty of entanglement of the ink, and the printing durability in a high dimension. Further, since electrochemical roughening using an alternating current is not performed, processing irregularity perpendicular to the traveling direction of the aluminum plate does not occur, and high speed aptitude is excellent in manufacturing.

In the method for producing an aluminum support for a lithographic printing plate according to the fourth aspect of the present invention, after the electrochemical surface roughening treatment and the etching treatment using mechanical or alternating current, the production apparatus of the present invention is used to obtain 0.05. Electrochemical surface roughening treatment is performed with an anode and a cathode having a length of ˜3V. Anode and cathode length is 0.
If it is less than 05 V, the formation of honeycomb pits tends to be non-uniform, which makes stable roughening difficult. Further, if it exceeds 3 V, the pit diameter of the honeycomb pit becomes too large, and it is not suitable as the honeycomb pit generated in the second roughening treatment.

The mechanical surface-roughening treatment is carried out by a method such as slurry brushing using a nylon brush, dry brushing using a wire brush, sandblasting, ball graining, embossing by pressing using a rolling roll or the like. . Sandblasting, grid blasting, shot blasting, chemical etching, metal melting by laser irradiation such as excimer laser and CO ₂ laser, and photoresist are used as a method for making unevenness on the surface of a rolling roll for pressing. It is possible to use a conventional pattern etching process or the like.

The chemical desmutting treatment and etching treatment in the above-mentioned acid or alkali aqueous solution are for removing the smut component generated on the surface of the aluminum plate by the roughening treatment, or for removing the natural oxide film, rolling oil and dirt. In order to achieve this, or to smooth the surface irregularities generated by mechanical surface roughening or electrochemical surface roughening. Examples of the acid aqueous solution used in the desmutting treatment and the etching treatment include aqueous solutions of hydrofluoric acid, fluorozirconic acid, phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, and the like, and examples of the alkaline aqueous solution include sodium hydroxide, potassium hydroxide, and the like.
There are aqueous solutions of tribasic sodium phosphate, sodium aluminate, sodium silicate, sodium carbonate and the like. These acid or alkali aqueous solutions can be used alone or in combination of two or more.

It is preferable to etch aluminum corresponding to an etching amount of 0.01 to 10 g / m ² . The conditions for performing such etching amount range are that the concentration of acid or alkali is 0.05 to 40%, and the liquid temperature is 40 to 100.
The temperature and the treatment time can be selected from the range of 5 to 300 seconds.

When the aluminum surface is chemically etched with an aqueous alkali solution, insoluble matter, that is, smut, is formed on the surface. For this smut, phosphoric acid, sulfuric acid, nitric acid, chromic acid, etc. can be removed by washing with a mixture thereof.

The aluminum surface to be electrochemically treated is preferably a clean surface without smut, but this can be omitted when the electrolytic solution is an acid and has a smut removing function, for example.

By the electrochemical roughening method using direct current in the method for producing an aluminum support for a lithographic printing plate according to the second and fourth aspects of the present invention, unevenness of 0.05 to 0.3 μm pitch is produced. In order to make it
Aqueous nitric acid solution containing g / l and having a concentration of 10 to 50 wt% 50 to 70 ° C
At a current density of 20 to 200 A / dm ² and a DC voltage of 10 to 30
Roughening is performed with an electric quantity of 0 C / dm ² . Especially the amount of electricity
10 to 100 C / dm ² is preferable. At this time, the anode and the cathode may be paired, and it is particularly preferable to start from the anodic reaction of the aluminum plate.

In order to generate unevenness of 0.05 to 0.3 μm pitch by an electrochemical surface roughening method using alternating current in the method for producing an aluminum support for a lithographic printing plate according to the third aspect of the present invention. Is aluminum ion 4-40g / l
Aqueous hydrochloric acid solution with a concentration of 1 to 2 wt% contained at 35 to 60 ° C. and an alternating voltage of current density of 10 to 100 A / dm ² at 10 to 300 C
This can be achieved by roughening with an electric quantity of / dm ² . As the AC voltage waveform and the electrolysis device at this time, a known metal plate roughening device can be used.

The electrochemical surface-roughening treatment using an alternating current in an aqueous solution containing nitric acid as a main component is performed by applying an alternating current between an electrode facing the aluminum plate in an aqueous solution containing nitric acid. Surface roughening treatment. The concentration of the nitric acid compound is preferably 0.1 g / l to the saturation limit, and 0.1 to 1
A range of 00 g / l is preferred. As the nitric acid compound, aluminum nitrate, sodium nitrate, ammonium nitrate and the like are preferable. It is preferable to mix an aqueous solution of nitric acid with an aluminum salt, an ammonium salt or the like in an amount of 0.1 to 100 g / l.
The temperature of the nitric acid aqueous solution is preferably in the range of 30 to 55 ° C.

As an alternating current waveform used for electrochemical surface roughening in an aqueous nitric acid solution, a sinusoidal wave as described in Japanese Patent Publication No. 48-28123 or a Japanese Patent Publication No. 55-25381 is disclosed. Sine wave alternating current phase controlled by thyristor,
Although a special waveform or the like can be used as described in JP-A-52-58602, it is preferable in terms of equipment to use a rectangular wave alternating current having a DUTY ratio of 1: 1.

The surface roughening treatment electrochemically carried out in an aqueous nitric acid solution using an alternating current preferably has a current density in the range of 10 to 200 A / dm ² . The amount of electricity is preferably in the range of 10 to 600 C / dm ² ,
A range of 10 to 300 C / dm ² is particularly preferable. The frequency at which the voltage or potential on the aluminum plate changes is preferably 160 Hz or less, more preferably 60 Hz to 0.1 Hz.

The electrochemical roughening treatment in an aqueous solution containing hydrochloric acid as a main component is carried out by electrochemically applying an alternating current between an electrode facing an aluminum plate in an aqueous solution containing hydrochloric acid. It means to process. The concentration of hydrochloric acid compound is 1.
The range of 0 g / l to the saturation limit is preferable, and the range of 5 to 100 g / l is more preferable. As the hydrochloric acid compound, aluminum chloride, sodium chloride, ammonium chloride, magnesium chloride and the like are preferable. It is preferable that 20 to 150 g / l of aluminum salt and ammonium salt are mixed with the hydrochloric acid aqueous solution. The temperature of the hydrochloric acid aqueous solution is preferably 30 to 55 ° C.

The alternating current waveform used for electrochemical roughening in a hydrochloric acid aqueous solution is the same as that in the case of a nitric acid aqueous solution.

In the roughening treatment which is carried out electrochemically in a hydrochloric acid aqueous solution using an alternating voltage, the current density is 10 to 200 A.
A range of / dm ² is preferred. The amount of electricity is preferably in the range of 10 to 800 C / dm ² . Frequency is 50Hz or more, preferably 60Hz
To 500 Hz.

The aluminum plate treated as described above was subjected to direct current or alternating current in an electrolytic solution containing sulfuric acid or phosphoric acid by a known method in order to improve hydrophilicity, water retention and printing resistance. Anodizing treatment can be performed. Further, the sealing treatment can be performed after the anodizing treatment. Further, it can be subjected to a hydrophilic treatment by immersing it in an aqueous solution containing sodium silicate or the like.

The photosensitive layer to be coated may be a positive type or a negative type. For example, for anodizing treatment, hydrophilizing treatment, and photosensitive layer, the methods and products described in JP-A-59-227494 and JP-A-59-182967 can be used.

Preferred embodiments of the treatment process incorporating the surface roughening treatment by the apparatus for producing an aluminum support for lithographic printing plates of the present invention are shown below.

Example 1 Chemical Etching Treatment in Acid or Alkali Aqueous Solution Treatment of electrochemically roughening an aluminum plate in an acidic aqueous solution using direct current voltage (treatment by the apparatus of the present invention ) Chemical etching treatment in aqueous acid or alkali solution Anodizing treatment, or anodizing treatment followed by hydrophilization treatment

Example 2 Chemical Etching Treatment in Aqueous Acid or Alkali Solution A treatment in which an aluminum plate is continuously electrochemically roughened in an acidic aqueous solution using a DC voltage (treatment by the apparatus of the present invention) ) Chemical Etching Treatment in Acid or Alkaline Aqueous Treatment Aluminous plate is continuously electrochemically roughened by using DC voltage in acidic aqueous solution (treatment by the apparatus of the present invention) Acid or alkaline aqueous solution Chemical etching treatment in anodizing treatment, or hydrophilic treatment after anodizing treatment

Example 3 Chemical Etching Treatment in Acid or Alkali Aqueous Solution Treatment of electrochemically roughening an aluminum plate in an acidic aqueous solution using a DC voltage (treatment by the apparatus of the present invention) ) Chemical etching treatment in an acid or alkaline aqueous solution Treatment for continuously electrochemically roughening an aluminum plate in an acidic aqueous solution using an AC voltage Chemical etching treatment in an acidic or alkaline aqueous solution Anodizing treatment or hydrophilic treatment after anodizing treatment

Example 4 Chemical Etching Treatment in Acid or Alkali Aqueous Solution Treatment of Aluminum Plate Roughly Electrochemically Surface Roughened in Acidic Aqueous Solution with AC Voltage In Acid or Alkaline Aqueous Solution Chemical Etching Treatment A treatment of electrochemically roughening an aluminum plate continuously in an acidic aqueous solution using a DC voltage (treatment by the apparatus of the present invention) Chemical etching treatment in an acid or alkali aqueous solution Anodizing treatment, or hydrophilizing treatment after anodizing treatment The chemical etching treatment in the acid or alkali aqueous solution performed in the first step removes stains, rolling oil, and natural oxide film on the aluminum plate and stabilizes. It is carried out for the purpose of uniformly roughening the surface.

The chemical etching treatment in an acid or alkali aqueous solution, which is performed in the middle of the electrochemical graining treatment using alternating current or direct current, can be omitted. Further, the processing can be performed by combining the examples 1 to 4. Furthermore, mechanical roughening treatment can be performed as a pretreatment for the combination of Examples 1 to 4 or Examples 1 to 4. After the hydrophilization treatment, a treatment of dipping for 1 to 300 seconds in a 50 to 80 ° C. aqueous solution containing 10 to 30 wt% of sulfuric acid may be performed.

In the case of the above-mentioned example 1, the length L of the electrode with respect to the traveling speed of the aluminum plate may be made different and repeated a plurality of times. In the case of example 2,
It is preferable that the length L of the electrode with respect to the traveling speed of the aluminum plate is different between and.

In Examples 2 and 3, when the traveling speed of the aluminum plate is V (m / sec), the length L of the anode or cathode is 0.5 V to 5 V, and the amount of electricity applied to the aluminum plate is 250. It is particularly preferable that it is ˜800 C / dm ² .

In Examples 2 and 4, it is particularly preferable that the length L of the anode or the cathode is 0.05 V to 3 V and the amount of electricity applied to the aluminum plate is 30 to 250 C / dm ² .

The above-described method for producing an aluminum support for a lithographic printing plate gives an extremely high quality support for a printing plate, but the above-described aluminum support for a lithographic printing plate is preferred. In the aluminum support for a lithographic printing plate of the present invention, large irregularities and small irregularities are formed in an overlapping manner. The pitch of the large unevenness is 1 to 20 μm when observed with a scanning electron microscope photograph of 750 times, and it is 1 μm.
When it is less than the above range, the ink is likely to be entangled in the halftone dots when the dampening water of the printing machine is squeezed. If it exceeds 20 μm,
The stain resistance of the bran is poor, and the printing durability is poor. Particularly, 1 to 10 μm is preferable. The pitch of the small irregularities is preferably 0.05 to 2 μm. If it exceeds 2 μm or if it is less than 0.05 μm, the blanket fouling performance deteriorates. The pitch of small irregularities is more preferably 0.05 to 1 μm, and particularly preferably 0.5 to 1 μm. When unevenness having a pitch of 0.05 to 0.3 μm is applied, if the unevenness of the unevenness having a pitch of 1 to 20 μm generated in the preceding stage is rounded and warped, a support having particularly good stain resistance can be obtained. When the edge portion is left, the support becomes a support on which the ink in the halftone dot is easily entangled.

The average roughness is 0.3 to 1.5 μm,
If the average roughness is less than 0.3 μm, the ink tends to become entangled in the halftone dots when the dampening water of the printing machine is squeezed, and if it exceeds 1.5 μm, the stain resistance and printing durability are poor. Inferior support. The average roughness is particularly preferably 0.4 to 0.8 μm.

An example of an apparatus for producing an aluminum support for a lithographic printing plate according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of an apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first embodiment of the present invention, and FIG. 2 is an enlarged perspective view of an anode part.

In FIG. 1, reference numeral 1 is an electrolytic cell, and an acidic aqueous solution 2 is stored in this electrolytic cell 1. A liquid supply nozzle 3 for supplying the acidic aqueous solution 2 is provided on one side of the electrolytic cell 1, and a drain pipe 4 for discharging the acidic aqueous solution 2 is provided on the other side. Further, a plurality of anodes 5 and cathodes 6 having the same shape are alternately arranged on the bottom of the electrolytic cell 1 through a partition wall 7 having a constant length, and each of the pair of anodes 5 and cathodes 6 is a DC power source. (Not shown).

A transport roller 8 is provided near both ends of the electrolytic cell 1 in a state of being substantially half-immersed in the acidic aqueous solution 2, and an aluminum plate 9 is stretched between the transport rollers 8 so that the acidic aqueous solution 2 is filled. You can drive.

Then, the traveling speed of the aluminum plate 9 is set to V
[M / sec], the length L [m] of the anode 5 in the traveling direction of the aluminum plate 9 as shown in FIG. 2 is L = 0.05.
It is set in the range of V to 5V.

FIG. 3 is a schematic view of another embodiment of the apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure, a plurality of electrolytic cells 11 are arranged in series. In this electrolytic cell 11, an anode 12 and a cathode 13 are provided one by one in parallel with the bottom surface, and a carrying roller 14 for carrying the aluminum plate 9 is provided, and the anode 12 and the cathode 13 are connected to a DC power supply 15 Connected through.

The length L in the traveling direction of the aluminum plate of the anode 12 and the cathode 13 in such a manufacturing apparatus is determined by the electrolytic cell.
The length of the anode 12 or the cathode 13 located parallel to the aluminum plate 9 at 11.

FIG. 4 is also a schematic view of another embodiment of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure, a plurality of anode electrolytic cells 21 and a plurality of cathode electrolytic cells 22 are alternately arranged in series. The anode electrolytic cell 21 is provided with an anode 23, and the cathode electrolytic cell 22 is provided with a cathode 24.
Is also provided, and transport rollers 25 and 26 for transporting the aluminum plate 9 are provided, respectively. The anode 23 and the cathode 24 of the anode electrolytic cell 21 and the adjacent cathode electrolytic cell 22 are connected via a power source 27.

The length L of the anode 23 and the cathode 24 in the traveling direction of the aluminum plate in such a manufacturing apparatus is determined by the anode 21 or the cathode positioned parallel to the aluminum plate 9 in the electrolytic cell 21 for the anode or the step tank 22 for the cathode. 22 lengths.

FIG. 5 is also a schematic view of another embodiment of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure, a plurality of electrolytic baths 31 for anodes and electrolytic baths 32 for cathodes are alternately arranged in series. In this electrolytic bath 31 for anode, an anode 33 is provided at a right angle to the bottom surface, and an electrolytic bath for cathode is used.
A cathode 34 is provided at 32 at a right angle to the bottom surface. And
The anode 33 and the cathode 34 of the anode electrolytic bath 31 and the adjacent cathode electrolytic bath 32 are connected via a DC power supply (not shown).
Below the anode 33 and the cathode 34, a transport roller 35 having a diameter larger than the wall thickness of the anode 33 and the cathode 34 is provided, and a transport roller 36 having a small diameter is provided on both upper sides of the anode 33 and the cathode 34, and an aluminum plate. 9 runs on the outside of the anode 33 and the cathode 34 in a substantially "U" shape.

The length L in the running direction of the aluminum plate of the anode 33 and the cathode 34 in such a manufacturing apparatus faces the aluminum plate 9 of the anode 33 or the cathode 34 in the electrolytic bath 31 for the anode or the electrolytic bath 32 for the cathode. That is, the length is two times the length of the anode 33 or the cathode 34 in which the acidic aqueous solution 2 is immersed.

FIG. 6 is also a schematic view of another embodiment of the apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure, a plurality of electrolytic cells 41 are provided in series. In this electrolytic cell 41, an anode 42 and a cathode 43 are arranged parallel to each other at a right angle to the bottom surface, and a partition wall 44 is provided between the anode 42 and the cathode 43. A large-diameter transport roller 45 is provided below the anode 41, the cathode 42, and the partition wall 44, and a small-diameter transport roller 46 is provided in the upper lateral direction of the anode 41 and the cathode 42. , Anode 41
And, the outer side of the cathode 42 is run in a substantially "U" shape.

The length L of the anode 42 and the cathode 43 in the running direction of the aluminum plate in such a manufacturing apparatus is determined by the electrolytic cell 41.
Is the length of the surface of the anode 42 or cathode 43 facing the aluminum plate 9, ie, the length immersed in the acidic aqueous solution 2.

FIG. 7 is also a schematic view of another embodiment of the apparatus for producing an aluminum support for a lithographic printing plate.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure, a plurality of electrolytic baths 51 are provided in series. In the electrolytic cell 51, an anode 52 and a cathode 53 are arranged at right angles to the bottom surface and in parallel with each other, and a partition wall 54 is provided between the anode 52 and the cathode 53.
A large-diameter transport roller 55 is provided below the partition wall 54, and a small-diameter transport roller 56 is provided above the anode 51 and the partition wall 55 and above the cathode 52 and the partition wall 55, respectively. The aluminum plate 9 is provided so as to travel in a substantially “U” shape between the anode 51 and the partition wall 55 and between the cathode 52 and the partition wall 55.

The length L of the anode 52 and the cathode 53 in the running direction of the aluminum plate in such a manufacturing apparatus is determined by the electrolytic cell 51.
Is the length of the surface of the anode 52 or the cathode 53 facing the aluminum plate 9, ie, the length immersed in the acidic aqueous solution 2.

FIG. 8 is an enlarged perspective view of another example of the anode. In the anode 61 shown in this figure, a plurality of anode pieces 62 are integrally fixed via an insulator 63, and the length L of the anode 61 is the entire length including the insulator 63.

FIG. 9 is also an enlarged perspective view of another example of the anode. The anode 71 shown in this figure has a plurality of anode rods 71 with a constant gap.
72 are arranged apart from each other.
The length L of 71 is the entire length including the gap 72.

FIG. 10 is a schematic view of an embodiment of an apparatus for manufacturing an aluminum plate support for a lithographic printing plate according to the second aspect of the present invention.

In the apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure, a plurality of vertical electrolytic cells 81 are provided in series. In this electrolytic cell 81, an anode 82 and a cathode 83 are arranged at right angles to the bottom surface and in parallel with each other.
A partition wheel 84 is provided between the partition 83 and 83. A transport roller 85 is provided below the partition wheel 84, and transport rollers 86 are provided above the anode 82 and the partition wall 84 and between the cathode 83 and the partition wall 84, respectively, and the aluminum plate 9 is Anode 82 and partition wall 84
Between them and between the cathode 83 and the partition wall 84 in a substantially "U" shape.

On the inner surface of the upper part of the side wall of the electrolytic cell 81, an annular dam plate 86 is provided so as to be adjacent thereto and vertically movable, and
From the position of the boundary line a between the aluminum plate 9 and the acidic aqueous solution 2 when the aluminum plate enters the acidic aqueous solution 2, the anti-aluminum plate traveling direction of the cathode 83 which is the electrode for performing the first electrolytic reaction of the invading aluminum plate 9. The length of the aluminum plate up to the portion c facing the end face b on the side, that is, the length H from the liquid level of the acidic aqueous solution 2 (the upper end face of the dam plate) to the cathode 83, makes the running speed of the aluminum plate V [ m / se
c], it is set to be 0 to 5 V [m]. In addition, a discharge tank (not shown) for discharging the acidic aqueous solution 2 overflowing from the electrolytic cell 81 over the barrier plate 86 is provided around the electrolytic cell 81.

FIG. 11 is an enlarged view of the essential portions of another embodiment of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the second aspect of the present invention.

The apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure is provided with a flat electrolytic cell 91,
The acidic aqueous solution 2 is stored in the electrolytic bath 91. Further, a cathode 92 and an anode 93 having the same shape are provided in the lower portion of the electrolytic cell 91, and a guide 94 and a transport roller 95 for the aluminum plate 9 to travel are provided above them.

Then, the aluminum plate 9 is used as the acidic aqueous solution 2
From the position of the boundary line d between the aluminum plate 9 and the acidic aqueous solution 2 when the aluminum plate 9 penetrates into the end of the cathode 92, which is an electrode for performing the first electrolytic reaction of the aluminum plate 9 that has penetrated, into the end e on the anti-aluminum plate running direction side. The length H of the aluminum plate up to the facing portion f, that is, the length H from the aluminum plate 9 entering the acidic aqueous solution 2 to the cathode 92 (=
h ₁ + h ₂ ) determines the traveling speed of the aluminum plate by V [m / se
c], it is set to be 0 to 5 V [m].

FIG. 12 is an enlarged view of the essential part of another embodiment of the apparatus for manufacturing an aluminum support for following a lithographic printing plate according to the second aspect of the present invention.

The apparatus for manufacturing an aluminum support for a lithographic printing plate shown in this figure is provided with a radial type electrolytic cell 101, and an acidic aqueous solution 2 is stored in this electrolytic cell 101.
A transport roller 102 is provided in the electrolytic bath 101 in a state of being almost immersed in the acidic aqueous solution 2, and the aluminum plate 9 runs along the transport roller 102.
Around the transport roller 102, a concentric cathode 103
And an anode 104.

Then, the aluminum plate 9 is used as the acidic aqueous solution 2
From the position of the boundary line i between the aluminum plate 9 and the acidic aqueous solution 2 when it penetrates into the aluminum plate to the part k facing the end part j of the cathode 103, which is the electrode for the first electrolytic reaction of the aluminum plate 9 that has entered. The length H of the plate, that is,
After the aluminum plate 9 has penetrated into the acidic aqueous solution 2, the cathode 10
The length H until reaching 3 is set to be 0 to 5 V [m] when the traveling speed of the aluminum plate is V [m / sec].

[0114]

【Example】

[Example 1] A JIS 1050 aluminum plate having a thickness of 0.3 mm was immersed in a 5% aqueous solution of sodium hydroxide for 60 seconds for chemical etching, washed with water, and then washed with 25%.
It was immersed in a sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Then, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an acidic aqueous solution, and the anode and the cathode were alternately arranged facing the aluminum plate, and a continuous DC voltage was applied between the anode and the cathode. In addition, an aluminum plate was passed through these electrodes with a distance of 10 mm kept between them to carry out an electrochemical roughening treatment. The current density of DC voltage is 70 (A / dm
² ) was.

At this time, the traveling speed of the aluminum plate is set to V
(m / sec), the length L of the anode and cathode is 0.05V,
Electrolysis treatment was performed by changing the voltage to 0.1V, 0.25V, 0.5V, 1V, 5V.

After that, the substrate was washed with water, immersed in a 5% aqueous solution of sodium hydroxide (containing 0.5% aluminum ions) at 35 ° C. for 90 seconds for chemical etching treatment, washed with water, and then in a 25% aqueous solution of sulfuric acid. It was immersed in 60 ° C. for 10 seconds and washed with water.

When the surface of this aluminum plate was observed with a scanning electron microscope, the honeycomb pits shown in Table 1 were formed.

[0119]

[Table 1]

From the above results, it is understood that the pit diameter can be adjusted to a predetermined length by adjusting the electrode length.

Example 2 A JIS 1050 aluminum plate having a thickness of 0.3 mm was placed in a 5% sodium hydroxide aqueous solution at 60 ° C.
After dipping for 2 seconds to carry out a chemical etching treatment, it was washed with water, then dipped in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an electrolytic solution, and a DUTY ratio of 1: was established between the electrode (carbon) facing the aluminum plate.
1. A rectangular wave AC voltage having a frequency of 60 Hz was applied, and electrochemical roughening treatment was performed for 14 seconds. The current density of the rectangular wave AC voltage was 25 A / dm ² . Then wash with water, then 25
% Aqueous solution of sulfuric acid at 60 ° C. for 60 seconds and washed with water.

Then, using 1% nitric acid aqueous solution (containing 0.5% aluminum ion) at 45 ° C. as an acidic aqueous solution, the anode and the cathode are alternately arranged facing the aluminum plate as shown in FIG. A continuous DC voltage was applied between them, and an aluminum plate was passed through these electrodes with a distance of 10 mm kept between them to carry out an electrochemical graining treatment. The current density of the DC voltage was 70 A / dm ² , and the amount of electricity applied to the aluminum plate was set to 150 C / dm ² . At this time, the traveling speed Vm / sec of the aluminum plate and the length L of the anode and cathode
Was 0.25V. Specifically, the traveling speed of the aluminum plate is 0.4 m / sec, and the length L of the anode and the cathode is 0.1 m.

After that, it was washed with water, immersed in a 5% aqueous solution of sodium hydroxide at 35 ° C. for 30 seconds for chemical etching treatment, washed with water, and immersed in a 25% aqueous sulfuric acid solution at 60 ° C. for 10 seconds, Washed with water.

When the surface of this aluminum plate was observed with a scanning electron microscope, it was found that the honeycomb pits of 2 to 5 μm generated by direct current were present in the honeycomb pits of 0.5 to 1 μm generated by alternating current. The surface shape was suitable as a plate support. Its average surface roughness is 0.4μ
It was m.

Example 3 A JIS 1050 aluminum plate having a thickness of 0.3 mm was placed in a 5% aqueous sodium hydroxide solution at 60 ° C.
After dipping for 2 seconds to carry out a chemical etching treatment, it was washed with water, then dipped in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Then, using 1% nitric acid aqueous solution (containing 0.5% aluminum ion) at 45 ° C. as an acidic aqueous solution, the anode and the cathode are alternately arranged facing the aluminum plate as shown in FIG. A continuous DC voltage was applied between them, and an aluminum plate was passed through these electrodes with a distance of 10 mm kept between them to carry out an electrochemical graining treatment. The current density of DC voltage was 70 A / dm ² .

At this time, the traveling speed Vm of the aluminum plate
/ Sec, the length L of the anode and the cathode was 0.4V.
Specifically, the traveling speed of the aluminum plate is 0.25 m / se.
c, the length L of the cathode and the anode is 0.1 m.

Then, 60% in 5% aqueous sodium hydroxide solution
It was immersed in a temperature of 40 ° C. for 40 seconds for chemical etching treatment, washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Then, using 1% nitric acid aqueous solution (containing 0.5% aluminum ion) at 45 ° C. as an electrolytic solution, the electrodes facing the aluminum plate were alternately arranged with the anode and the cathode, and a continuous DC voltage was applied between the anode and the cathode. Then, the aluminum plate was passed through these electrodes at a distance of 10 mm from these electrodes to carry out an electrochemical roughening treatment. DC voltage current density is 70 A / dm
^{Was 2} .

At this time, the traveling speed Vm of the aluminum plate
/ Sec, the length L of the anode and the cathode was 0.1V.
Specifically, the traveling speed of the aluminum plate is 1 m / sec,
The length L of the anode and the cathode is 0.1 m.

After that, it was washed with water, immersed in a 5% aqueous solution of sodium hydroxide at 35 ° C. for 30 seconds to carry out a chemical etching treatment, then washed with water, immersed in a 25% aqueous solution of sulfuric acid at 60 ° C. for 10 seconds and washed with water. did.

The surface of this aluminum plate was observed with a scanning electron microscope to find that it was 3 to 10 μm produced by electrochemical roughening by direct current in the first step and chemical etching.
Among the honeycomb pits of No. 2, there is a honeycomb pit of 1 to 2 μm formed by electrochemical roughening by direct current in the second stage, and has a surface shape suitable as a lithographic printing plate support. It was The average surface roughness was 0.6 μm.

Example 4 A JIS 1050 aluminum plate having a thickness of 0.3 mm was immersed in a 5% aqueous solution of sodium hydroxide at 60 ° C. for 60 seconds for chemical etching, washed with water, and then a 25% aqueous solution of sulfuric acid. It was immersed in medium 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% hydrochloric acid aqueous solution (containing 0.5% aluminum ions) at 35 ° C. was used as an electrolytic solution, and a DUTY ratio of 1: was set between the electrode (carbon) facing the aluminum plate.
1. A rectangular wave AC voltage having a frequency of 120 Hz was applied, and electrochemical roughening treatment was performed for 20 seconds. The current density of the rectangular wave AC voltage was 60 A / dm ² . After that, it is washed with water, immersed in a 5% aqueous sodium hydroxide solution at 35 ° C for 60 seconds for chemical etching, further washed with water, and then at 60 ° C.
It was immersed in a 25% sulfuric acid aqueous solution for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) was used as an acidic aqueous solution, and the anode and the cathode were alternately arranged facing the aluminum plate as shown in FIG. 1, and between the anode and the cathode. A continuous DC voltage was applied, and the aluminum plate was passed through these electrodes with a distance of 10 mm, and electrochemical roughening treatment was performed. The DC voltage has a current density of 70 A / dm ² and the amount of electricity applied to the aluminum plate is 150 C
It was set to be / dm ² . At this time, the traveling speed Vm / sec of the aluminum plate and the length L of the anode and the cathode are 0.1
It was V. Specifically, the traveling speed of the aluminum plate is 1 m / sec, and the length L of the anode and the cathode is 0.1 m. Then, it was washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 60 seconds and washed with water.

When the surface of this aluminum plate was observed by a scanning electron microscope, it was found that the pits of 1 to 2 μm generated by direct current were present in the pits of 5 to 20 μm generated by alternating current. The surface shape was suitable as a plate support. Its average surface roughness is 0.7μ
It was m.

Example 5 In the aqueous nitric acid solution of Example 3,
Ammonium nitrate is added, and ammonium ion is 100p
Roughening treatment was performed in the same manner except that pm was set. As a result, honeycomb pits similar to those in Example 3 were formed.

[Example 6] A JIS 1050 aluminum plate having a thickness of 0.3 mm was subjected to surface roughening by a press using a metal roll which was subjected to a surface roughening treatment using a CO ₂ laser.

Next, 40% in a 5% aqueous sodium hydroxide solution was added.
After dipping for 2 seconds to carry out a chemical etching treatment, it was washed with water, then dipped in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Then, using 1% nitric acid aqueous solution (containing 0.5% aluminum ion) at 45 ° C. as an acidic aqueous solution, the anode and the cathode are alternately arranged facing the aluminum plate as shown in FIG. A continuous DC voltage was applied between them, and an aluminum plate was passed through these electrodes with a distance of 10 mm kept between them to carry out an electrochemical graining treatment. The current density of DC voltage was 70 A / dm ² .

At this time, the traveling speed Vm of the aluminum plate
/ Sec, the length L of the anode and the cathode was 0.1V. Specifically, the traveling speed of the aluminum plate is 1 m / se
c, the length L of the anode and the cathode is 0.1 m.

After that, it was washed with water, immersed in a 5% aqueous solution of sodium hydroxide at 35 ° C. for 30 seconds for chemical etching treatment, washed with water, and immersed in a 25% aqueous sulfuric acid solution at 60 ° C. for 10 seconds, Washed with water.

The surface of this aluminum plate was observed with a scanning electron microscope. As a result, it was found that unevenness of 5 to 50 μm pitch was produced by roughening by pressing and chemical etching.
1st-stage generated by electrochemical roughening with direct current
There was a honeycomb pit of ˜2 μm, and the surface shape was suitable as a support for a lithographic printing plate. The average surface roughness was 0.5 μm.

Example 7 A JIS 1050 aluminum plate having a thickness of 0.3 mm was immersed in a 5% aqueous sodium hydroxide solution for 60 seconds for chemical etching, and then washed with water.
Then, it was immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an acidic aqueous solution, the anode and the cathode were alternately arranged facing the aluminum plate, and a continuous DC voltage was applied between the anode and the cathode. In addition, an aluminum plate was passed through these electrodes with a distance of 10 mm kept between them to carry out the electrochemical graining treatment of the first stage. The current density of DC voltage is
It was 70 (A / dm ² ), and the amount of electricity applied to the aluminum plate at the time of the anode was 400 (C / dm ² ).

At this time, the traveling speed of the aluminum plate is set to V
(M / sec), the length L of the anode and the cathode was 0.5V. Then, it was washed with water and then immersed in a 60 ° C. aqueous sodium hydroxide solution at 60 ° C., and chemical etching amounts were set to 0.5, 1, ^{2, 5, 8} (g / m ² ) as shown in Table 2. . Then, it was immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an electrolytic solution, and a DUTY ratio of 1: was set between the electrode (carbon) facing the aluminum plate.
1. A rectangular wave alternating current having a frequency of 60 Hz was added, and a second stage electrochemical graining treatment was performed for 14 seconds.

After that, the substrate was washed with water, immersed in a 5% aqueous solution of sodium hydroxide (containing 0.5% aluminum ions) at 35 ° C. for 20 seconds for chemical etching treatment, washed with water, and then immersed in a 25% aqueous solution of sulfuric acid. It was immersed in 60 ° C. for 10 seconds and washed with water.

When the surface of this aluminum plate was observed with a scanning electron microscope, the results shown in Table 2 were obtained.

[0151]

[Table 2]

The surface shape was evaluated by sensory evaluation by observing a scanning electron micrograph (the same applies hereinafter). A: Excellent B: Good

Example 8 A JIS 1050 aluminum plate having a thickness of 0.3 mm was immersed in a 5% aqueous solution of sodium hydroxide for 60 seconds for chemical etching, and then washed with water.
Then, it was immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an acidic aqueous solution, and the anode and the cathode were alternately arranged facing the aluminum plate, and a continuous DC voltage was applied between the anode and the cathode. In addition, an aluminum plate was passed through these electrodes with a distance of 10 mm kept between them to carry out an electrochemical roughening treatment. The current density of DC voltage is 70 (A / dm
² ) was.

At this time, the traveling speed of the aluminum plate is set to V
(M / sec), the length L of the anode and cathode is 0.05
The electrolytic treatment was carried out by changing V, 0.125V, 0.25V, 0.5V, 1V, 2V, 8V.

Then, 60% in 5% aqueous sodium hydroxide solution
It was immersed in a temperature of 40 ° C. for 40 seconds for chemical etching treatment, washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an electrolytic solution, and a DUTY ratio of 1: was set between the electrode (carbon) facing the aluminum plate.
1. A rectangular wave AC voltage having a frequency of 60 Hz was applied, and electrochemical roughening treatment was performed for 14 seconds. The current density of the rectangular wave AC voltage was 25 A / dm ² .

After that, it was washed with water, immersed in a 5% aqueous solution of sodium hydroxide (containing 0.5% aluminum ions) at 35 ° C. for 20 seconds for chemical etching treatment, washed with water and then in a 25% aqueous solution of sulfuric acid. It was immersed in 60 ° C. for 10 seconds and washed with water.

The surface of this aluminum plate was observed with a scanning electron microscope. As a result, it was found that the roughening using direct current in the first step and the second step in the pit formed in the sodium hydroxide aqueous solution were carried out. It had a structure in which the honeycomb pits of 0.5 to 1 μm generated by the surface roughening using were overlapped.

[0160]

[Table 3] A: Excellent B: Good C: Yes

[Example 9] A JIS 1050 aluminum plate having a thickness of 0.3 mm was roughened by a press using a metal roll which was roughened with a nylon brush and a Pumington suspension.

Next, it was immersed in a 5% aqueous sodium hydroxide solution for 40 seconds for chemical etching treatment, washed with water, then immersed in a 25% aqueous sulfuric acid solution at 60 ° C. for 10 seconds and washed with water.

Then, a 1% nitric acid aqueous solution (0.5% aluminum
Aluminum (including um ions) at 45 ℃ as an electrolyte
The electrodes facing the plate are arranged alternately with the anode and the cathode.
A continuous DC voltage is applied between the
These electrodes are passed with a 10 mm gap between them and
Roughening treatment was performed. DC voltage current density is 70 A / dm ²
Met.

At this time, the moving speed Vm of the aluminum plate
/ Sec, the length L of the anode and the cathode was 0.125V.

After that, it was washed with water, immersed in a 5% aqueous solution of sodium hydroxide at 35 ° C. for 30 seconds for chemical etching treatment, washed with water, immersed in a 25% aqueous solution of sulfuric acid at 60 ° C. for 10 seconds, and washed with water. did.

The surface of this aluminum plate was observed with a scanning electron microscope. As a result, it was found that the surface was roughened with a nylon brush and a Pamington solution, and was formed by chemical etching.
In the unevenness of 20 μm pitch, there is a honeycomb pit of 1 to 2 μm generated by electrochemical roughening by direct current in the second step, and has a surface shape suitable as a support for lithographic printing plates. Was there. The average surface roughness was 0.6 μm.

Then, an anodizing treatment, coating of a photosensitive layer and drying were carried out in accordance with a conventional method to prepare a printing plate, which was then printed. As a result, a good printing plate was obtained. Sometimes the ink was hard to get tangled.

[Example 10] Examples 8-2, 8-3, 8-
Using an aluminum plate of No. 4, 8-5, or 8-6, and then performing anodizing treatment, coating of a photosensitive layer, and drying in accordance with a conventional method, a printing plate was prepared and printed. Plate, especially Examples 8-3, 8-4, 8
The printing plate using the aluminum plate of -5 had an excellent balance of printing performance.

[Embodiment 11] Examples 1-3, 1-4, 1-
5 aluminum plate and then aluminum
At 25 ° C in a nitric acid aqueous solution containing 25 g / l of 34% concentration
Current density 30A / dm ²The direct current of the aluminum plate as the anode
Electrolysis for 2 seconds, and the surface is treated with a fineness of 0.1-0.3 μm.
Fine honeycomb pits were created. Then in a sulfuric acid solution
It was desmutted and then washed with water. Then always
Anodizing treatment, coating of photosensitive layer and drying
I made a printing plate and printed it.
there were.

[Embodiment 12] Embodiments 1-3, 1-4, 1-
Using the aluminum plate of No. 5 and then 1.5% hydrochloric acid aqueous solution (containing 0.5% aluminum ion) at 35 ° C. as an electrolytic solution, a DUTY ratio of 1: 1 and frequency between the electrode (carbon) facing the aluminum plate. A rectangular wave AC voltage of 120 Hz was applied, and electrochemical roughening treatment was performed for 5 seconds. The current density of the rectangular wave AC voltage was 25 A / dm ² .

After that, it was washed with water, immersed in a 5% aqueous solution of sodium hydroxide (containing 0.5% aluminum ions) at 35 ° C. for 10 seconds for chemical etching treatment, washed with water and then in a 25% aqueous solution of sulfuric acid. It was immersed in 60 ° C. for 10 seconds and washed with water.

The surface of this aluminum plate was observed with a scanning electron microscope. As a result, it was found that the roughening using direct current in the first step and the alternating current in the second step in the pits formed in the sodium hydroxide aqueous solution. It had a structure in which honeycomb pits of 0.1 to 0.3 μm, which were generated by the surface roughening using, were overlapped.

Thereafter, anodizing treatment, coating of a photosensitive layer and drying were carried out in accordance with a conventional method to prepare a printing plate and printing was carried out. As a result, a good printing plate was obtained. The ink was not easily entangled in the halftone dots.

[Example 13] A JIS 1050 aluminum plate having a thickness of 0.24 mm was immersed in a 5% aqueous sodium hydroxide solution at 60 ° C.
After being immersed for 20 seconds for chemical etching treatment, it was washed with water, then immersed in a 1% nitric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Then, 1% nitric acid aqueous solution containing 0, 35, 70, 140, 280 and 560 g / l of aluminum nitrate (containing 75 ppm ammonium ion containing 0.35 g / l of ammonium nitrate) was acidified at 45 ° C. As an aqueous solution, the anode and the cathode are alternately arranged facing the aluminum plate, a continuous DC voltage is applied between the anode and the cathode, and the aluminum plate is allowed to pass with a distance of 10 mm between these electrodes, and the electrochemical roughening is performed. Surface treatment was performed. There were 4 pairs of anode and cathode. The DC voltage had a current density of 200 (A / dm ² ). A quantity of electricity of 400 C / dm ² was applied to the aluminum plate at the time of anode.
The length of the anode and the cathode was 20 mm, and the moving speed of the aluminum plate was 2.4 m / min.

The leading electrode of each tank was the cathode. The distance from the liquid surface where the aluminum plate was dipped to the electrode was 10 mm.

The electrolytically surface-roughened aluminum plate was washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 60 seconds and washed with water. When the surfaces of these aluminum plates were observed with a scanning electron microscope, honeycomb pits were formed.

The electrolytically roughened aluminum plate was
Rinse with water and immerse in an aluminum plate at 25 ° C for 10 seconds in a 25% sodium hydroxide aqueous solution (containing 5% aluminum ion).
After etching at 5.5 g / m ^2, it was washed with water. Next, it was immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

The surfaces of these aluminum plates were observed with a scanning electron microscope, and the waviness due to the cross-sectional profile was measured with a stylus type surface roughness meter having a tip of 1 μmR.
The results are shown in Table 4.

[0180]

[Table 4]

FIG. 13 shows the relationship between the aluminum nitrate concentration and the average roughness.

Example 14 A JIS1050 aluminum plate having a thickness of 0.24 mm was immersed in a 5% aqueous sodium hydroxide solution at 60 ° C.
After being immersed for 20 seconds for chemical etching treatment, it was washed with water, then immersed in a 1% nitric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, 1, 5 and ammonium ammonium nitrate were added to a 1% aqueous nitric acid solution containing 70 g / l of aluminum nitrate.
Using 45, 90g / l added acidic aqueous solution at 45 ℃, the anode and the cathode are alternately arranged facing the aluminum plate, and continuous DC voltage is applied between the anode and the cathode. After passing through with a space, electrochemical graining treatment was performed. The current density of DC voltage is 70 (A / d
m ² ). 420 C / dm ^{2 on the} aluminum plate at the time of anode
The amount of electricity was added. Aluminum plate moving speed is 24m
/ Min, and the electrode length was 100 mm for both the anode and cathode. The anodic reaction and the cathodic reaction were performed 24 times each.

The electrolytically surface-roughened aluminum plate was washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 60 seconds and washed with water. When the surfaces of these aluminum plates were observed with a scanning electron microscope, honeycomb pits as shown in Table 5 were formed.

[0185]

[Table 5]

Example 15 Using an aluminum plate which was electrochemically roughened in Example 13-3, the aluminum plate was immersed in an aqueous sodium hydroxide solution at 60 ° C. at 60 ° C. and the chemical etching amount was adjusted to 5.5. (G / m ² ), then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water. After that, according to a conventional method, anodizing treatment, application of a positive photosensitive layer, and drying were performed to prepare a printing plate, and printing was performed. Printing durability, blanc stain, and tangling of ink when squeezed water were good. It was a printed version.

Example 16 Using an aluminum plate which was electrochemically surface-roughened in Example 13-5, the aluminum plate was immersed in an aqueous sodium hydroxide solution at 60 ° C. at 60 ° C. and the chemical etching amount was adjusted to 5.5. (G / m ² ), then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water. After that, according to a conventional method, anodizing treatment, application of a positive photosensitive layer, and drying were performed to prepare a printing plate, and printing was performed. Printing durability, blanc stain, and tangling of ink when squeezed water were good. It was a printed version.

Example 17 After the anodizing treatment of Example 16, an aqueous solution containing 2.5% sodium silicate was dipped in 70 ° C. for 10 seconds, subjected to a hydrophilizing treatment, and then washed with water. After that, a negative photosensitive layer was applied and dried to prepare a printing plate, which was then printed, and it was a good printing plate.

Example 18 The aluminum plate electrochemically roughened in Example 13-3 was used, and then 60
It was immersed in an aqueous solution of sodium hydroxide at 60 ° C. and the chemical etching amount was set to 5.5 (g / m ² ). Then 60 ° C
It was immersed in a 25% sulfuric acid aqueous solution for 10 seconds and then washed with water.

This aluminum plate was replaced with aluminum nitrate 70
Nitric acid 1 added with g / l and ammonium nitrate 0.35 g / l
% Aqueous solution at 40 ° C., electrochemical roughening treatment was carried out for 6 seconds with a rectangular wave alternating current having a DUTY ratio of 1: 1 and a current density of 50 A / dm ² with carbon as the counter electrode, followed by washing with water. Next, the aluminum plate was subjected to an etching treatment in a 5% aqueous solution of caustic soda to dissolve the aluminum plate at 0.5 g / m ² . 25% sulfuric acid solution,
It was immersed in 60 ° C. for 120 seconds and then washed with water.

Next, an anodizing treatment was carried out using a direct current at 33% at a sulfuric acid aqueous solution of 10%, followed by washing with water. As a result of observing this surface with a scanning electron microscope, irregularities of 0.5 to 1 μm were uniformly generated in irregularities with a large pitch, and compared with Comparative Example 1, apparently irregularities were formed. The average surface roughness was 0.60 μm.

When a positive type photosensitive layer was applied to this aluminum plate to obtain a lithographic printing plate, it was a good printing plate. Compared to Comparative Example 1, the other printing performances were not deteriorated, and especially the blank smearing performance was obtained. It was improving.

Example 19 After the anodic oxidation treatment of Example 18, an aqueous solution containing 2.5% sodium silicate was dipped in 70 ° C. for 10 seconds, subjected to a hydrophilizing treatment, and then washed with water. After that, a negative photosensitive layer was formed, a printing plate was prepared and printed, and it was a good printing plate.

Example 20 Electrochemical surface roughening was performed in exactly the same manner as in Example 21-3 except that 70 g / l of aluminum nitrate was added to a 2% aqueous nitric acid solution.

The electrolytically surface-roughened aluminum plate was washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 60 seconds and washed with water. When the surfaces of these aluminum plates were observed with a scanning electron microscope, honeycomb pits having an average diameter of about 3 to 5 μm were formed, but the surface was more uniform than that of Example 13-3.

Also, the aluminum plate after electrolytic surface roughening was
Rinse with water and immerse in an aluminum plate at 25 ° C for 10 seconds in a 25% sodium hydroxide aqueous solution (containing 5% aluminum ion).
After etching at 5.5 g / m ^2, it was washed with water. Next, it was immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

When the surfaces of these aluminum plates were observed with a scanning electron microscope, large undulations with an average pitch of 3 to 7 μm were observed.

This aluminum plate was replaced with aluminum nitrate 70
Nitric acid 1 added with g / l and ammonium nitrate 0.35 g / l
% Aqueous solution at 40 ° C., electrochemical roughening treatment was carried out for 6 seconds with a rectangular wave alternating current having a DUTY ratio of 1: 1 and a current density of 50 A / dm ² with carbon as the counter electrode, followed by washing with water. Next, the aluminum plate was subjected to an etching treatment in a 5% aqueous solution of caustic soda to dissolve the aluminum plate at 0.5 g / m ² . 25% sulfuric acid solution,
It was immersed in 60 ° C. for 120 seconds and then washed with water.

Next, an anodizing treatment was carried out using a direct current at 33% at a sulfuric acid aqueous solution of 10%, followed by washing with water. As a result of observing this surface with a scanning electron microscope, irregularities of 0.5 to 1 μm were uniformly generated in irregularities with a large pitch, and compared with Comparative Example 1, apparently irregularities were formed. The average surface roughness was 0.5 μm.

When a positive photosensitive layer was applied to this aluminum plate to prepare a lithographic printing plate, it was a good printing plate.

[Example 21] A JIS1050 aluminum plate having a thickness of 0.24 mm was immersed in a 5% aqueous sodium hydroxide solution at 60 ° C.
After being immersed for 20 seconds for chemical etching treatment, it was washed with water, then immersed in a 1% nitric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ion and 150 ppm ammonium ion) 45
With an acidic aqueous solution at ℃, an anode and a cathode are alternately arranged opposite to the aluminum plate in a device as shown in Fig. 1, a continuous DC voltage is applied between the anode and the cathode, and the aluminum plate is separated from these electrodes by a distance of 10 mm. And was allowed to pass therethrough to carry out an electrochemical graining treatment. The current density of DC voltage is 100 (A / dm
² ) was. The length of the anode and the cathode was 150 mm, and the moving speed of the aluminum plate was 9 m / min.

At this time, the traveling speed of the aluminum plate is set to V
(M / sec), the electrolytic treatment was performed with the length L of the anode and the cathode set to 1V. The top electrode of each tank was the cathode.

As shown in Table 1, the distance H from the liquid surface to the cathode is 0.06V, 0.3V, depending on the weir plate A made of soft PVC.
It was set to 0.6V, 1V and 2V. The distance from the liquid surface to the anode
It was 0.07V.

Then, after washing with water and immersing in a 25% sodium hydroxide aqueous solution (containing 5% aluminum ion) at 60 ° C. for 10 seconds to etch a 5.5 g / m ² aluminum plate,
Washed with water. Next, soak in 60% in 25% sulfuric acid aqueous solution for 10 seconds,
Washed with water.

When the surface of this aluminum plate was observed with a scanning electron microscope, the honeycomb pits shown in Table 6 were formed.

[0207]

[Table 6]

[Example 22] A JIS1050 aluminum plate having a thickness of 0.24 mm was immersed in a 5% aqueous sodium hydroxide solution at 60 ° C.
After being immersed for 20 seconds for chemical etching treatment, it was washed with water, then immersed in a 1% nitric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Thereafter, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions and 150 ppm ammonium ions) 45
With an acidic aqueous solution at ℃, an anode and a cathode are alternately arranged opposite to the aluminum plate in a device as shown in Fig. 1, a continuous DC voltage is applied between the anode and the cathode, and the aluminum plate is separated from these electrodes by a distance of 10 mm. And was allowed to pass therethrough to carry out an electrochemical graining treatment. The length ratio of the anode and the cathode was 2: 3. The DC voltage current density is 150 (A
/ Dm ² ), the second, third and fourth tank anodes are 75 (A / d)
m ² ). The length of the anode was 100 mm, and the moving speed of the aluminum plate was 6 m / min.

At this time, the traveling speed of the aluminum plate is set to V
(M / sec), the length L of the anode was set to 1 V to carry out the electrolytic treatment. The top electrode of each tank was the cathode.

The distance from the liquid surface to the cathode is 0.3 each
V, and the distance from the liquid surface to the anode was 0.6V. The leading electrode of each tank was the cathode.

Then, after washing with water and immersing in a 25% sodium hydroxide aqueous solution (containing 5% of aluminum ion) at 60 ° C. for 10 seconds to etch a 5.5 g / m ² aluminum plate,
Washed with water. Next, soak in 60% in 25% sulfuric acid aqueous solution for 10 seconds,
Washed with water.

Observation of the surface of this aluminum plate with a scanning electron microscope revealed that honeycomb pits having an average diameter of 6 to 8 μm were uniformly formed, and the average surface roughness was 0.72.
was μm.

Example 23 The aluminum plate of Example 21-4 was used, and thereafter, an electrode (carbon) facing the aluminum plate using 1% nitric acid aqueous solution (containing 0.5% aluminum ion) at 45 ° C. as an electrolytic solution. And DUTY ratio 1:
1. A rectangular wave alternating current having a frequency of 60 Hz was added, and a second stage electrochemical graining treatment was performed for 14 seconds.

Then, it was washed with water, immersed in a 5% sodium hydroxide aqueous solution (containing 0.5% aluminum ions) at 35 ° C. for 20 seconds to carry out a chemical etching treatment, then washed with water and then in a 25% sulfuric acid aqueous solution. It was immersed in 60 ° C. for 10 seconds and washed with water.

Observation of the surface of this aluminum plate with a scanning electron microscope revealed that honeycomb pits having an average diameter of 0.5 to 1 μm were formed in the undulations having an average pitch of 5 to 8 μm.

Thereafter, according to a conventional method, anodizing treatment in an aqueous solution mainly containing sulfuric acid, washing with water, drying, coating of a photosensitive layer,
After drying and printing a positive printing plate, it was a good printing plate with good stain, printing durability, tone reproducibility and ink removal. Especially when squeezing the dampening water on the printing machine. The ink was difficult to get entangled.

[Example 24] Under the same conditions as in Example 21-2,
The dam plate B as shown in FIG. 2 was installed in each tank. The material of the barrier plate was soft vinyl chloride, and the clearance between the barrier plate and the aluminum web was 2 mm. When the surface of the aluminum plate after the electrochemical roughening treatment was observed, the treatment unevenness due to the fluctuation of the liquid surface was better than that of Example 21-2.

[Comparative Example 1] A JIS 1050 aluminum plate having a thickness of 0.3 mm was roughened by a press using a metal roll which was roughened with a nylon brush and a Pumington suspension.

Then, 60% in 5% aqueous sodium hydroxide solution
It was immersed in a temperature of 40 ° C. for 40 seconds for chemical etching treatment, washed with water, then immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

Then, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an electrolytic solution, and a DUTY ratio of 1: was set between the electrode (carbon) facing the aluminum plate.
1. A rectangular wave AC voltage having a frequency of 60 Hz was applied, and electrochemical roughening treatment was performed for 14 seconds. The current density of the rectangular wave AC voltage was 25 A / dm ² .

After that, it was washed with water, and it was kept in a 5% sodium hydroxide aqueous solution (containing 0.5% aluminum ion) at 35 ° C.
After dipping for 2 seconds to carry out a chemical etching treatment, it was washed with water, immersed in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds, and washed with water.

When the surface of this aluminum plate was observed with a scanning electron microscope, local deep crepe-shaped recesses formed by roughening with a nylon brush and a Pamington solution were unevenly present.

After that, an anodizing treatment, coating of the photosensitive layer and drying were carried out in accordance with a conventional method to prepare a printing plate and printing was carried out. As a result, the printing plate was good, but the blanc stain performance was slightly inferior.

[Comparative Example 2] A JIS1050 aluminum plate having a thickness of 0.3 mm was placed in a 5% sodium hydroxide aqueous solution at 60 ° C.
After dipping for 2 seconds to carry out a chemical etching treatment, it was washed with water, then dipped in a 25% sulfuric acid aqueous solution at 60 ° C. for 10 seconds and washed with water.

After that, a 1% nitric acid aqueous solution (containing 0.5% aluminum ions) at 45 ° C. was used as an electrolytic solution, and a DUTY ratio of 1: was set between the electrode (carbon) facing the aluminum plate.
1. A rectangular wave AC voltage having a frequency of 60 Hz was applied, and electrochemical roughening treatment was performed for 14 seconds. The current density of the rectangular wave AC voltage was 25 A / dm ² .

After that, the plate was washed with water, immersed in a 5% aqueous solution of sodium hydroxide at 35 ° C. for 10 seconds for chemical etching treatment, washed with water, immersed in a 25% aqueous solution of sulfuric acid at 60 ° C. for 10 seconds, and washed with water. did.

After that, an anodizing treatment, coating of the photosensitive layer and drying were carried out in accordance with a conventional method to prepare a printing plate, and printing was carried out. A good printing plate was obtained. When squeezing the dampening water above, the ink was a little tangled.

[Comparative Example 3] An aluminum plate was treated in the same manner as in Example 21-2 except that the positions of the cathode and the anode were reversed. Honeycomb pits whose surface shape was smaller than that of Example 21-2 were formed.

[0230]

INDUSTRIAL APPLICABILITY According to the present invention, since uniform honeycomb pits can be formed on an aluminum support for a lithographic printing plate, an aluminum support having a very good rough surface can be obtained for a lithographic printing plate. In addition, it is possible to obtain a suitable printing plate in which the ink is not entangled at the halftone dots when the dampening water is squeezed.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of an apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 2 is an enlarged perspective view of an anode part of the manufacturing apparatus shown in FIG.

FIG. 3 is a schematic view of another embodiment of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 4 is a schematic view of another embodiment of the apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 5 is a schematic view of another embodiment of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 6 is a schematic view of another embodiment of the apparatus for producing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 7 is a schematic view of another embodiment of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 8 is an enlarged perspective view of another example of the anode of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 9 is an enlarged perspective view of another example of the anode of the apparatus for manufacturing an aluminum support for a lithographic printing plate according to the first aspect of the present invention.

FIG. 10 is a schematic view of an example of an apparatus for manufacturing an aluminum support for a lithographic printing plate according to the second aspect of the present invention.

FIG. 11 is a schematic view of another example of an apparatus for manufacturing an aluminum support for a lithographic printing plate according to the second aspect of the present invention.

FIG. 12 is a schematic view of another example of an apparatus for manufacturing an aluminum support for a lithographic printing plate according to the second aspect of the present invention.

FIG. 13 is a graph showing the relationship between aluminum nitrate concentration and average roughness.

[Explanation of symbols]

 1, 22, 31, 32, 41, 51, 81, 91, 101 ... Electrolytic cell 2 ... Acidic aqueous solution 5, 12, 23, 33, 42, 52, 61, 82, 93, 104 ... Anode 6, 13, 24 , 34, 43, 53, 83, 92, 103 ... Cathode 9 ... Aluminum plate

Claims (11)

[Claims] 1. At least one electrolytic cell, an acidic aqueous solution stored in the electrolytic cell, an anode and a cathode alternately arranged in the acidic aqueous solution and supplied with a DC voltage, and an aluminum plate in the acidic aqueous solution. When the traveling speed of the aluminum plate is V [m / sec], the length L [m] of each of the anode and cathode aluminum plates in the traveling direction is defined as V [m / sec]. 0.05V ~ 5V
[M] is an apparatus for manufacturing an aluminum support for a lithographic printing plate. 2. At least one electrolytic cell, an acidic aqueous solution stored in the electrolytic cell, an anode and a cathode alternately arranged in the acidic aqueous solution and supplied with a DC voltage, and an aluminum plate in the acidic aqueous solution. It has a conveyance roller arranged so as to travel, and the traveling speed of the aluminum plate is V
When [m / sec] is set, from the position of the boundary line between the aluminum plate and the acidic aqueous solution when the aluminum plate penetrates into the acidic aqueous solution, the direction of the anti-aluminum plate running direction of the electrode that carries out the first electrolytic reaction of the invading aluminum plate The length of the aluminum plate up to the position facing the end on the side is 0 to 5V.
[M] is an apparatus for manufacturing an aluminum support for a lithographic printing plate. 3. The planographic printing plate according to claim 2, wherein a weir plate is provided around the electrolytic cell to adjust a position of a boundary line between the aluminum plate and the acidic aqueous solution when the aluminum plate enters the acidic aqueous solution. For manufacturing aluminum supports for automobiles. 4. The apparatus for producing an aluminum support for a lithographic printing plate according to claim 1, wherein the cathode is provided at the tip of the electrolytic cell in the traveling direction of the anti-aluminum plate, and the treatment is started from the anode reaction of the aluminum plate. 5. At least one electrolytic cell, an acidic aqueous solution stored in the electrolytic cell, an anode and a cathode alternately arranged in the acidic aqueous solution and supplied with a DC voltage, and an aluminum plate in the acidic aqueous solution. It has a transport roller arranged so as to run, and the acidic aqueous solution has aluminum nitrate of 20 g / l to saturation and ammonium nitrate of 0.1 g / l.
~ An apparatus for manufacturing an aluminum support for a lithographic printing plate, which is characterized by being saturated. 6. At least one electrolytic cell, an acidic aqueous solution stored in the electrolytic cell, an anode and a cathode alternately arranged in the acidic aqueous solution and supplied with a DC voltage, and an aluminum plate in the acidic aqueous solution. A method for roughening an aluminum support for a lithographic printing plate, which comprises causing an aluminum plate to undergo an anode reaction or a cathode reaction at least three times or more using a device having a transport roller arranged so as to run. 7. The surface of the aluminum plate is sequentially subjected to (a) chemical etching treatment in an acid or alkali aqueous solution, and (b) using the manufacturing apparatus of claim 1, an anode having a length of 0.1 to 5 V. And electrochemically roughening the surface with a cathode, and (c) chemically etching with an acid or alkali aqueous solution, and (d) using the manufacturing apparatus according to claim 1, with an anode and a cathode having a length of 0.05 to 3V. A method for producing an aluminum support for a lithographic printing plate, which comprises electrochemically roughening treatment and (e) chemically etching treatment in an acid or alkali aqueous solution. 8. The surface of an aluminum plate is sequentially subjected to (a) chemical etching treatment in an acid or alkaline aqueous solution, and (b) using the production apparatus of claim 1, an anode having a length of 0.1 to 5 V. And electrochemically surface-roughened at the cathode, (c) chemically etched with an acid or alkali aqueous solution, (d) electrochemically surface-roughened with an alternating current in an acidic aqueous solution, (e) A method for producing an aluminum support for a lithographic printing plate, which comprises chemically etching in an acid or alkali aqueous solution. 9. The surface of an aluminum plate is, in order, (a) mechanically roughened, or chemically etched in an acid or alkali aqueous solution and then electrochemically roughened using an alternating current. And (b) chemically etching with an acid or alkali aqueous solution, and (c) using the production apparatus of claim 1, electrochemically roughening the surface with an anode and a cathode having a length of 0.05 to 3V. And (d) a chemical etching treatment in an acid or alkali aqueous solution, which is a method for producing an aluminum support for a lithographic printing plate. 10. The production of an aluminum support for a lithographic printing plate according to claim 7, 8 or 9, which is carried out by chemical etching treatment in an acid or alkali aqueous solution and then anodizing treatment or by anodizing treatment. Method. 11. An unevenness having an average pitch of 1 to 20 μm and an average of 0.
An aluminum support for a lithographic printing plate, which is formed by overlapping irregularities having a pitch of 05 to 2 μm and has an average surface roughness of 0.3 to 1.5 μm.