JP2002362046A - Method for manufacturing support for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a support for a lithographic printing plate which is capable of forming a uniformly irregular rough surface on an aluminum alloy plate containing a large quantity of Cu without strictly adjusting conditions for a surface roughing process. SOLUTION: This method for manufacturing the support for a lithographic printing plate comprises the steps to obtain the support for a lithographic printing plate by applying a surface treatment including an electrochemical surface roughing process to the aluminum alloy plate. The Cu content of the aluminum alloy plate is 0.001 to 1 mass% and the electrochemical surface roughing process is performed in an aqueous acidic solution containing a chemical compound which can form Cu and a complex.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a support for a lithographic printing plate, and more particularly to a method for stably performing a roughening treatment without being particularly limited to the composition of an aluminum alloy plate as a raw material. Therefore, the present invention relates to a method for producing a lithographic printing plate support capable of significantly reducing raw material costs and obtaining a lithographic printing plate support excellent in printing performance and surface quality.

[0002]

2. Description of the Related Art A photosensitive lithographic printing plate using an aluminum alloy plate as a support is widely used for offset printing. This lithographic printing plate is obtained by making a lithographic printing plate precursor. A lithographic printing plate precursor is generally obtained by subjecting one or both surfaces of an aluminum alloy plate to a surface roughening treatment, applying a photosensitive liquid, and drying to form a photosensitive layer.
In addition, in order to improve abrasion resistance during printing of the lithographic printing plate, anodizing treatment is generally performed after the surface roughening treatment. In order to shorten the vacuum contact time during plate making, a layer having fine irregularities on the surface called a mat layer may be provided on the surface of the photosensitive layer.

A lithographic printing plate precursor is made into a lithographic printing plate after processing such as image exposure, development, and washing with water. As a method of image exposure, a method of providing a difference between an image part and a non-image part by bringing a lithographic film on which an image is printed into close contact with a lithographic printing plate precursor and irradiating light, using a laser or projecting an image Thus, a method of directly writing an image portion or a non-image portion on a lithographic printing plate precursor to provide a difference between the image portion and the non-image portion, and the like can be given. In the development, the photosensitive layer in the exposed portion is removed in the positive type lithographic printing plate precursor, and the photosensitive layer in the non-exposed portion is removed in the negative type lithographic printing plate precursor. Here, the photosensitive layer is removed, and the surface of the lithographic printing plate support, that is, the portion where the aluminum alloy plate surface or the anodic oxide film surface is exposed becomes a non-image portion showing hydrophilicity, and the photosensitive layer is not removed. The remaining portion becomes an image portion showing lipophilicity (lipophilicity). After development, if necessary, hydrophilic treatment, gumming,
Burning processing and the like are performed.

[0004] The lithographic printing plate thus obtained is mounted on a plate cylinder of a printing press and used for printing. In printing, ink and fountain solution are supplied to the surface of a lithographic printing plate. The ink adheres to the image area of the lipophilic lithographic printing plate, and water adheres to the non-image area of the hydrophilic lithographic printing plate. After the ink in the image area is transferred to the blanket cylinder, it is further transferred to a printing material such as paper, and printing is completed.

[0005] The lithographic printing plate support used as described above is designed to have uniform unevenness on its surface for the purpose of improving water retention, printing durability, tone reproducibility and the like.
A roughening process has been performed. Conventionally, as a method of surface roughening of an aluminum alloy plate, an electrochemical surface roughening method (hereinafter also referred to as "electrolytic surface roughening") in which electrolytic etching is performed using an electrolytic solution mainly containing nitric acid, and a mechanically rough surface. A general method, a chemical surface roughening method, or a combination thereof is generally used. Among them, the electrolytic surface roughening method using an electrolytic solution mainly composed of nitric acid is suitably used because a uniform roughened surface with a rough surface is obtained and the printing performance is excellent.

[0006]

Incidentally, the use of the lithographic printing plate precursor differs for each user, and the required characteristics such as its strength also differ. On the other hand, conventionally, strength and the like are adjusted mainly by adjusting alloy components of the aluminum alloy sheet and adjusting rolling conditions of the aluminum alloy sheet. In particular,
This is largely due to the adjustment of the alloy components of the aluminum alloy plate. On the other hand, in recent years, from the viewpoint of effective use of global energy, etc., the market price is higher than that of aluminum materials without adjusting alloy components as raw materials, for example, scrap materials containing various impurities and new ingots. There has been an increasing demand for producing a lithographic printing plate support using inexpensive ingots containing secondary elements or reclaimed ingots containing many impurity elements.

However, in the electrolytic surface roughening method using an aqueous solution mainly composed of nitric acid, which has been conventionally used to obtain uniform unevenness, it is necessary to strictly adjust the alloy components of the aluminum alloy plate. is there. And when the composition of the alloy component fluctuates, the roughened shape changes greatly,
When the conditions of the surface roughening treatment are fixed, it is possible to form a roughened shape with uniform irregularities on an aluminum alloy plate made of various aluminum materials, particularly an aluminum alloy plate having a high content of impurity elements. There was a problem that it was not possible. Among them, the aluminum alloy plate obtained by scraping a beverage can and recycling it contains a large amount of Cu having an effect of coarsening the pits in the electrochemical graining treatment, so that a preferable uniform honeycomb pit is formed. It was difficult to do. Therefore, the present invention provides a planographic printing plate support capable of forming a roughened surface with uniform irregularities on an aluminum alloy plate containing a large amount of Cu without strictly adjusting the conditions of the surface roughening treatment. It is intended to provide a method for producing a body.

[0008]

Means for Solving the Problems The present inventors have achieved the above object.
As a result of intensive research to achieve this, it can form a complex with Cu
Perform electrolytic surface roughening treatment in an acidic aqueous solution containing a compound.
Al with a wide range of compositions, including those with a high Cu content
Strictly adjust the surface roughening conditions for the minium alloy plate.
Pit diameter is small and uniform
Found that it is possible to obtain a surface shape with
Was. Further, the present inventor has proposed a rough surface having such a surface shape.
The aluminum alloy plate that has been subjected to surface treatment is
Positive-type or negative-type visible light exposure type plate making
Lithographic printing plate precursor with layer
Not only can it be used preferably,
Lithographic printing plate of lithographic printing plate precursor with laser-shaped plate
That it can be suitably used as a plate support
Heading, the present invention was completed.

That is, the present invention relates to an aluminum alloy plate,
A method for producing a lithographic printing plate support, wherein the lithographic printing plate support is subjected to a surface treatment including an electrochemical surface roughening treatment to obtain a lithographic printing plate support, wherein the Cu content of the aluminum alloy plate is 0.001 to 0.001.
1% by mass, and the electrochemical graining treatment
The present invention provides a method for producing a lithographic printing plate support, which is carried out in an acidic aqueous solution containing a compound capable of forming a complex with u.

The aluminum alloy plate is made of Fe, Si,
The present invention contains three or more elements selected from the group consisting of Cu, Mg, Mn, Zn, Cr and Ti in the following range, and has an aluminum content of 95 to 99.4 mass%. This is one of the preferable embodiments. Fe: 0.2
0 to 1.0% by mass, Si: 0.10 to 1.0% by mass, C
u: 0.03 to 1.0 mass%, Mg: 0.1 to 1.5 mass%, Mn: 0.1 to 1.5 mass%, Zn: 0.03 to
0.5% by mass, Cr: 0.005 to 0.1% by mass, T
i: 0.01 to 0.5% by mass

The present invention also provides a lithographic printing plate support obtained by the method for producing a lithographic printing plate support described above. Further, the present invention provides a lithographic printing plate precursor comprising a photosensitive layer provided on the lithographic printing plate support.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. <Aluminum alloy plate (rolled aluminum)> The aluminum alloy plate used in the present invention is a dimensionally stable metal containing aluminum as a main component and having a Cu content of 0.001.
-1% by mass of an aluminum alloy. In the present invention, fine and uniform honeycomb pits can be obtained even when an aluminum alloy plate having a high Cu content is used. As the aluminum alloy plate, a plastic film or paper on which an aluminum alloy is laminated or vapor-deposited may be used. Furthermore, Japanese Patent Publication No. 48-1
A composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in JP-A-8327 can also be used.

Although the aluminum content of the aluminum alloy plate is not particularly limited, the aluminum content is 95 to 95%.
Even if the content is 99.4% by mass, a preferable rough surface can be obtained, so that the aluminum content of 95 to 99.4% by mass is one of the preferable embodiments of the present invention.

The aluminum alloy plate is made of Fe, S
It is one of the preferred embodiments to contain three or more elements selected from the group consisting of i, Cu, Mg, Mn, Zn, Cr and Ti in the following ranges. This is because crystal grains of aluminum become finer in such a case.

Fe: 0.20 to 1.0% by mass, Si:
0.10 to 1.0 mass%, Cu: 0.03 to 1.0 mass%, Mg: 0.1 to 1.5 mass%, Mn: 0.1 to 1.
5 mass%, Zn: 0.03 to 0.5 mass%, Cr: 0.
005 to 0.1% by mass, Ti: 0.01 to 0.5% by mass

Further, the aluminum alloy plate can contain elements such as Bi and Ni and unavoidable impurities as long as the effects of the present invention are not impaired.

The aluminum alloy plate used in the present invention has a Cu content of 0.001 to 1% by mass, preferably an aluminum content of 95 to 99.4% by mass. The above elements are contained in the above range, but the composition is not specified, and those of conventionally known and used materials, for example, JIS A105
0, JIS A1100, JIS A3003, JIS
A3004, JIS A3005, Internationally registered alloy 3
An aluminum alloy plate such as 103A can be used as appropriate. The method of manufacturing the aluminum alloy sheet may be either a continuous casting method or a DC casting method, and an aluminum alloy sheet in which the DC annealing method has not been subjected to intermediate annealing or soaking can be used. In the final rolling, an aluminum alloy plate having irregularities by lamination rolling, transfer, or the like may be used. The aluminum alloy plate used in the present invention may be a continuous band-shaped sheet material or plate material, which may be an aluminum web, and a sheet-like sheet cut to a size corresponding to a planographic printing plate precursor shipped as a product. It may be a sheet. The thickness of the aluminum alloy plate used in the present invention is usually 0.05 to 1
mm, and preferably 0.1 mm to 0.5 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the desire of the user.

In the method for producing a lithographic printing plate support of the present invention, the aluminum alloy plate includes an electrochemical surface roughening treatment in an acidic aqueous solution containing a compound capable of forming a complex with Cu. The surface treatment is performed to obtain a lithographic printing plate support. The surface treatment may further include various treatments. In the various steps used in the present invention, since the alloy component of the aluminum alloy plate used is eluted in the processing solution used in the process, the processing solution contains the alloy component of the aluminum alloy plate. In particular, it is preferable to add these alloy components before the treatment and use the treatment liquid in a steady state.

In the present invention, it is preferable to carry out an alkali etching treatment or a desmutting treatment before the electrochemical graining treatment, and it is also preferable to carry out the alkali etching treatment and the desmutting treatment in this order. After the electrochemical surface-roughening treatment, it is preferable to carry out an alkali etching treatment or a desmut treatment, and it is also preferable to carry out the alkali etching treatment and the desmut treatment in this order. Further, the alkali etching treatment after the electrochemical graining treatment can be omitted.
In the present invention, it is also preferable to perform a mechanical surface roughening treatment before these treatments. Further, the electrochemical graining treatment may be performed twice or more. After these, it is also preferable to perform anodizing treatment, sealing treatment, hydrophilic treatment, and the like.

In particular, the surface treatment includes an alkali etching treatment, a desmutting treatment, an electrochemical graining treatment in an aqueous solution containing a compound capable of forming a complex with Cu, an alkali etching treatment and / or a desmutting treatment, and an anode. Including the oxidation treatment in this order is one of the preferred embodiments of the present invention. In this case, it is one of preferred embodiments of the present invention that the surface treatment includes a sealing treatment and / or a hydrophilization treatment after the anodizing treatment. In this case, it is one of the preferable aspects of the present invention that the surface treatment includes a mechanical surface roughening treatment before the first alkali etching treatment.

Hereinafter, mechanical surface roughening treatment, first alkali etching treatment, first desmutting treatment, electrochemical surface roughening treatment, second alkali etching treatment, second desmutting treatment, anodic oxidation treatment, sealing treatment, Each of the hydrophilic treatments will be described in detail. In the present specification, the process performed before the electrochemical surface roughening process is called with an ordinal number of “first”, and the process performed after the electrochemical surface roughening process is called an “ordinal number” of “second”. Sometimes called with.

<Mechanical surface-roughening treatment> The mechanical surface-roughening treatment is preferably performed before the electrochemical surface-roughening treatment. In general, mechanical surface roughening treatment is a roller-shaped brush in which a large number of brush bristles such as synthetic resin bristles made of synthetic resin such as nylon (trade name), propylene, and vinyl chloride resin are implanted on the surface of a cylindrical body. Is performed by rubbing one or both of the surfaces of the aluminum alloy plate while spraying a slurry liquid containing an abrasive onto a rotating roller brush. Instead of the roller brush and the slurry liquid,
A polishing roller which is a roller having a surface provided with a polishing layer can also be used. The length of the bristles in the roller-shaped brush can be appropriately determined according to the outer diameter of the roller-shaped brush and the diameter of the body, but generally, 10 to 100 m.
m.

Known abrasives can be used for the abrasive used in the present invention. For example, abrasives such as pumice stone, silica sand, aluminum hydroxide, alumina powder, volcanic ash, carborundum, diamond sand, or a mixture thereof can be used. Among them, pumistone and silica sand are preferred, and silica sand is particularly preferred because it is harder and less susceptible to breakage than pamistone, so that the surface roughening efficiency is excellent. The average particle size of the abrasive is preferably from 3 to 50 μm from the viewpoint that the surface roughening efficiency is excellent and the graining pitch can be narrowed, and from 6 to 50 μm.
More preferably, it is 45 μm. When using pamistone as the abrasive, the average particle size is particularly preferably 40 to 45 μm, and when using silica sand as the abrasive, the average particle size is particularly preferably 20 to 25 μm. The polishing slurry is used as a polishing slurry liquid, for example, by suspending it in water. The polishing slurry liquid may contain a thickener, a dispersant (for example, a surfactant), a preservative, and the like, in addition to the abrasive. The average particle diameter is defined as the particle diameter at which the cumulative ratio is 50% when the cumulative distribution of the ratio of the abrasive particles of each particle diameter to the volume of the total abrasive contained in the polishing slurry liquid is taken. Say.

In the mechanical roughening process, first, prior to performing the brush graining, if necessary,
A degreasing treatment for removing rolling oil on the surface of the aluminum alloy plate, for example, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like may be performed.

<First Alkali Etching Process> In the first alkali etching process, etching is performed by bringing the aluminum alloy plate into contact with an alkaline solution.
The first alkali etching treatment is for removing rolling oil, dirt and natural oxide film on the surface of the aluminum alloy plate (rolled aluminum) when the mechanical surface roughening treatment is not performed, and When the mechanical surface roughening treatment is performed, it is performed for the purpose of dissolving the edge portion of the unevenness generated by the mechanical surface roughening treatment and obtaining a surface having a smooth undulation. As a method of bringing the aluminum alloy plate into contact with the alkali solution, for example, a method of passing the aluminum alloy plate through a tank containing an alkali solution lukari solution, a method of immersing the aluminum alloy plate in a tank containing an alkali solution And a method of spraying an alkaline solution onto the surface of the aluminum alloy plate.

The etching amount is preferably ¹ to 15 g / m ² for the surface subjected to the electrolytic surface roughening treatment in the next step, and 0.1 g / m ² for the surface not subjected to the electrolytic surface roughening treatment.
1 to 5 g / m ² (approximately 10 to 4 g
0%). When the etching amount is within the above range, the rolling oil (oils and fats), dirt, and natural oxide film on the surface of the aluminum alloy plate (rolled aluminum) are completely removed when the mechanical surface roughening treatment is not performed. Therefore, when a lithographic printing plate is used, the water retention in the non-image area is excellent, and so-called blank stain (blanket stain) or the like that occurs when ink adheres to the non-image area is preferable. In addition, when the mechanical surface roughening process is performed, the edge portions of the irregularities generated by the mechanical surface roughening process are sufficiently dissolved.

Examples of the alkali used in the alkali solution include caustic alkali and alkali metal salts. Specifically, as caustic alkali, for example,
Kasei soda and Kaseikari. Examples of the alkali metal salt include alkali metal silicates such as sodium silicate, sodium silicate, potassium metasilicate, and potassium silicate; alkali metal carbonates such as sodium carbonate and potassium carbonate; sodium aluminate; Alkali metal aluminates such as potassium acid; alkali metal aldonates such as sodium gluconate and potassium gluconate; sodium diphosphate, potassium diphosphate, sodium tertiary phosphate, potassium tertiary phosphate, etc. Alkali metal hydrogen phosphate is mentioned. Among them, a solution of caustic alkali and a solution containing both caustic alkali and an alkali metal aluminate are preferable from the viewpoint of high etching rate and low cost. In particular,
An aqueous solution of caustic soda is preferred.

Although the concentration of the alkaline solution can be determined according to the etching amount, it is preferably 1 to 50% by mass, more preferably 10 to 35% by mass. When aluminum ions are dissolved in the alkaline solution, the concentration of aluminum ions is 0.01 to
It is preferably 10% by weight, more preferably 3 to 8% by weight. The temperature of the alkaline solution is preferably from 20 to 90C. The processing time is preferably from 1 to 120 seconds. The amount of the etching treatment is preferably for 1 to 15 g / m ² dissolution, it is more preferable to 3~12g / m ² dissolution. The first alkali etching treatment can be performed using an etching bath usually used for etching an aluminum plate. As the etching tank, either a batch type or a continuous type can be used. In the case where the first alkali etching treatment is performed by spraying an alkali solution onto the surface of the aluminum alloy plate, a spray device can be used.

<First Desmut Treatment> In the first desmut treatment, for example, the above aluminum alloy plate is treated with hydrochloric acid, nitric acid,
It is carried out by contacting with an acidic solution such as sulfuric acid having a concentration of 0.5 to 30% by mass (containing 0.01 to 5% by mass of aluminum ions). Examples of the method of bringing the aluminum alloy plate into contact with the acidic solution include a method of passing the aluminum alloy plate through a tank containing the acidic solution, a method of immersing the aluminum alloy plate in a tank containing the acidic solution, A method of spraying the solution onto the surface of the aluminum alloy plate can be used. In the first desmutting treatment, as an acidic solution, a waste solution of an aqueous solution mainly composed of nitric acid or an aqueous solution mainly composed of hydrochloric acid discharged in the electrolytic surface roughening treatment described later, or sulfuric acid discharged in an anodic oxidation treatment described later It is preferable to use a waste liquid of an aqueous solution mainly composed of The liquid temperature of the first desmutting treatment is 25 to 90 ° C.
It is preferred that Further, the processing time of the first desmutting process is preferably 1 to 180 seconds. Aluminum and aluminum alloy components may be dissolved in the acidic solution used for the first desmutting treatment.

<Electrolytic surface-roughening treatment> The present invention is characterized in that the electrolytic surface-roughening treatment is performed in an acidic aqueous solution containing a compound capable of forming a complex with Cu. The acidic aqueous solution is not particularly limited, but an aqueous solution mainly containing nitric acid and an aqueous solution mainly containing hydrochloric acid are preferable. The aqueous solution mainly composed of nitric acid preferably has a nitric acid concentration of 5 to 15 g / L, more preferably 7 to 13 g / L, and an aluminum ion concentration of 3 to 15 g / L. And more preferably 3 to 7 g / L. The concentration of aluminum ions in the aqueous solution mainly containing nitric acid can be adjusted by adding aluminum nitrate to a nitric acid aqueous solution having the above-mentioned nitric acid concentration. The aqueous solution mainly composed of hydrochloric acid preferably has a hydrochloric acid concentration of 5 to 15 g / L, more preferably 5 to 10 g / L, and an aluminum ion concentration of 3 to 15 g / L. And more preferably 3 to 7 g / L. The concentration of aluminum ions in the aqueous solution mainly containing hydrochloric acid can be adjusted by adding aluminum chloride to an aqueous solution of hydrochloric acid having the above-mentioned hydrochloric acid concentration. Further, the aqueous solution mainly composed of nitric acid and the aqueous solution mainly composed of hydrochloric acid are Fe, Si, Cu, Mg, Mn, Z
It can contain ions such as n, Cr, Ti, and unavoidable impurities. The temperature of the aqueous solution mainly composed of nitric acid is 30
The temperature is preferably from 70 to 70 ° C, more preferably from 40 to 60 ° C. The temperature of the aqueous solution mainly composed of hydrochloric acid is 25
The temperature is preferably from about 50 ° C to 50 ° C, more preferably from 30 to 45 ° C.

The acidic aqueous solution used in the present invention contains a compound capable of forming a complex with Cu. Here, the “compound capable of forming a complex with Cu” refers to a compound such as a molecule or an ion capable of forming a complex with Cu existing as an alloy element on the surface of the aluminum alloy plate. Compounds that can form a complex with Cu include, for example, ammonia; methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, cyclohexylamine, triethanolamine, triisopropanolamine, E
Amines obtained by replacing the hydrogen atom of ammonia such as DTA (ethylenediaminetetraacetic acid) with a hydrocarbon group (aliphatic, aromatic, etc.); and metal carbonates such as sodium carbonate, potassium carbonate, potassium hydrogencarbonate and the like. It is. Also,
Ammonium salts such as ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate and ammonium carbonate are also included. These ammonium salts are generally obtained by reacting ammonia with an acid.

Form a complex with Cu used in the present invention
Compounds form stable Cu complexes in the above acidic aqueous solution.
Can be achieved. For example, ammonia and amines
Can form an ammonia complex of Cu.
Specifically, ammonia has the chemical formula [Cu (NH_Three)_Four(H_Two
O)_Two]²⁺Form an ammonia complex of Cu represented by
Can be. This Cu ammonia complex has a
Four NHs in a square around the periphery_ThreeExists and a Cu atom
Two H's above and below_TwoThe configuration that O exists
ing. Also, for example, metal carbonates are all chemically
The formula [Cu (CO _Three)_Two]²⁺Cu carbonate ion complex represented by
Can be formed.

In the electrochemical graining treatment according to the present invention, a compound capable of forming a complex with Cu contained in the acidic aqueous solution selectively reacts with Cu existing as an alloy element on the surface of the aluminum alloy plate. It forms a complex and is stably present as a complex ion of Cu in an acidic aqueous solution. As a result, Cu eluted from the surface of the aluminum alloy plate is selectively removed, and does not adhere again to the surface of the aluminum alloy plate. Thereby, the effect of increasing the diameter of the Cu pit is suppressed, and an extremely fine and uniform honeycomb pit can be obtained. Such a surface shape is obtained for an aluminum alloy plate having a wide range of compositions including a case where the Cu content is large, and is particularly suitable as a lithographic printing plate support used for a lithographic printing plate precursor having a laser plate-making layer. is there.

Further, in order to remove Cu present on the surface of the aluminum alloy plate practically by a reaction at a relatively low temperature and in a short time, it is necessary to form a complex of a compound capable of forming a complex with Cu. It is preferable to select conditions that promote the reaction. For this purpose, it is preferable that the acidic aqueous solution contains an oxidizing agent in addition to the compound capable of forming a complex with Cu. As the oxidizing agent, for example, hydrogen peroxide (H ₂ O
₂ ) and potassium permanganate (KMnO ₄ ).
The content of the oxidizing agent in the acidic aqueous solution depends on the type of the oxidizing agent,
Although it depends on the content of the compound capable of forming a complex with Cu and the like, the concentration is usually preferably 1 to 100 g / L.

The electrochemical graining treatment is carried out using alternating current or direct current. In the present invention, it is preferable to use alternating current. The alternating current used for the electrolytic surface roughening treatment is not particularly limited, and for example, a sine wave (sine wave) current, a rectangular wave current, a triangular wave current, and a trapezoidal wave current can be used. Among them, a sine wave current and a trapezoidal wave current are preferable.
In the present invention, the alternating current may be any of a single phase, a two phase, a three phase and the like, but it is preferable to use two or more phases because the surface roughening efficiency is excellent. Alternatively, a current obtained by superimposing an alternating current and a direct current can be used. The AC frequency is not particularly limited, but is preferably 40 to 120 Hz, and 40 to 80 Hz.
Hz, more preferably 50-60 Hz. When the frequency of the alternating current is 40 to 120 Hz, the cost of manufacturing the power supply device can be reduced.

When the aluminum alloy plate becomes the anode,
Quantity of electricity, ie, quantity of electricity at the time of anode Q _aAnd when it comes to the cathode
Quantity of electricity, that is, the quantity of electricity at the time of cathode Q_cAnd the ratio Q_c/ Q_a
Is 0.9 to 1, the surface of the aluminum alloy plate is evenly distributed.
Preferred because it can form a uniform honeycomb pit
No. More preferably, Q_c/ Q_aIs 0.95 to 0.99
It is. Dividing the anode current of the main electrode through electrolytic surface treatment
When using an AC electrolytic cell with auxiliary electrodes
Are disclosed in JP-A-60-43500 and JP-A-1-5
As described in US Pat.
By controlling the current value of the flowing anode current, Q
_c/ Q_aCan be controlled.

The duty of the alternating current is not particularly limited.
From the viewpoint of uniformly roughening the surface of the aluminum alloy plate and manufacturing the power supply device, 0.33 to 0.66
Is preferable, more preferably 0.4 to 0.6, and most preferably 0.5. Note that the "duty" in the present invention, the period of the AC T, the aluminum alloy plate refers to a t _a / T when the time for anodic reaction (anode reaction time) was t _a. During the cathode reaction, an oxide film mainly composed of aluminum hydroxide is formed on the surface of the aluminum alloy plate, and further, the oxide film may be dissolved or broken. When dissolution or destruction of the oxide film occurs, the portion where dissolution or destruction occurs becomes a starting point of the pitting reaction at the time of the next anodic reaction of the aluminum alloy plate. Therefore, the selection of the duty of the alternating current is particularly important in performing a uniform electrolytic surface roughening treatment.

In the case of a trapezoidal wave current, the time TP until the current value in the alternating current reaches zero or a positive or negative peak is preferably 0.5 to 6 msec, and is 0.6 to 5 msec. Is more preferable, and
More preferably, it is 7 to 3 msec. Within the above range, more uniform crater-shaped concave portions (pits) are formed on the surface of the aluminum alloy plate. The amount of electricity from the start to the end of the electrolytic surface roughening treatment is 10 to 1000 C / d in total when the aluminum alloy plate is the anode.
m ² is preferable, 10 to 800 C / dm ² is more preferable, and 40 to 500 C / dm ² is further preferable. Current I _cp Peak anode current I _ap peak cycle side, and the cathode cycle side in an alternating current is preferably from 20 to 100 A / dm ² respectively, more that a 30~80A / dm ² More preferably, it is 40 to 60 A / dm ² . Further, I _cp / I _ap is preferably from 0.9 to 1.5, and more preferably from 0.9 to 1.0.

In the electrolytic surface roughening treatment, in one or two or more AC electrolytic cells, at least one pause period in which no alternating current flows through the aluminum alloy plate is provided, and the length of the pause period is 0.001 to 0. The time of 6 seconds is preferable because the honeycomb pits are uniformly formed on the entire surface of the aluminum alloy plate. The time is more preferably 0.005 to 0.55 seconds, and still more preferably 0.01 to 0.5 seconds. When two or more AC electrolytic cells arranged in series are used, the time during which no AC flows through the aluminum alloy plate between one AC electrolytic cell and another AC electrolytic layer is set to 0.001 to 20 seconds. Is preferred. More preferably, it is 0.1 to 15 seconds, and still more preferably 1 to 12 seconds.

For the electrolytic surface roughening treatment, a vertical type, a flat type,
An electrolytic surface roughening treatment device having various types of AC electrolytic cells such as a radial type can be used. Among them, a device having a flat type or radial type AC electrolytic cell is preferable.
Further, an electrolytic surface roughening treatment apparatus in which a plurality of AC electrolytic cells are arranged in series can also be suitably used. FIG. 1 shows a schematic cross-sectional view of an example of an electrolytic surface roughening treatment apparatus including a flat type AC electrolytic cell suitably used in the present invention. The electrolytic surface roughening apparatus 100 performs an electrolytic surface roughening treatment by applying a three-phase alternating current (hereinafter also referred to as a “three-phase alternating current”) while conveying the aluminum web W in a substantially horizontal direction. It is a chemical treatment device.

The electrolytic surface-roughening treatment apparatus 100 includes a shallow box-shaped AC electrolytic cell 2 extending along the conveying direction a of the aluminum web W and having an open upper surface, and a conveying direction near the bottom of the AC electrolytic cell 2. 3A, three plate-shaped main poles 4A, 4B, and 4C arranged in parallel with the transfer surface T, which is a transfer path of the aluminum web W, and in the transfer direction a inside the AC electrolytic cell 2. In the vicinity of an end on the upstream side (hereinafter, simply referred to as “upstream side”) and on the downstream side (hereinafter, simply referred to as “downstream side”) with respect to the transport direction a,
Transport rollers 6A and 6B for transporting the aluminum web W inside the AC electrolytic cell 2, an introduction roller 8A located upstream of the AC electrolytic cell 2 and introducing the aluminum web W into the AC electrolytic cell 2, A lead roller 8B is provided on the downstream side above the AC electrolytic cell 2 and guides the aluminum web W that has passed through the inside of the AC electrolytic cell 2 to the outside of the AC electrolytic cell 2. The acidic aqueous solution described above is stored inside the AC electrolytic cell 2. Main pole 4
A, 4B, and 4C are connected to a U terminal, a V terminal, and a W terminal of an AC power supply _Tac that generates three-phase AC, respectively. Therefore, the alternating currents applied to the main poles 4A, 4B and 4C are out of phase by 120 °.

The operation of the electrolytic surface roughening apparatus 100 will be described below. The aluminum web W is introduced into the AC electrolytic cell 2 by the introduction roller 8A, and is transported at a constant speed along the transport direction a by the transport rollers 6A and 6B. Inside the AC electrolytic cell 2, the aluminum web W moves parallel to the main poles 4A, 4B and 4C, and an alternating current is applied from the main poles 4A, 4B and 4C. Thereby, the aluminum web W
In, the anodic reaction and the cathodic reaction occur alternately. When the anodic reaction is occurring, mainly honeycomb pits are generated, and when the cathodic reaction is occurring, a film of aluminum hydroxide is mainly generated, and the surface is roughened. Is done. The alternating current applied to the main poles 4A, 4B and 4C is shifted in phase by 120 ° as described above, so that the main pole 4B has a phase difference of 120 ° from the phase (U phase) of the main pole 4A.
The anodic reaction and the cathodic reaction are repeated at a delayed phase (V phase), and the main electrode 4C is one cycle longer than the main electrode 4B.
The anodic reaction and the cathodic reaction are repeated at a phase (W phase) delayed by 20 °. Therefore, in the aluminum web W, the anodic reaction and the cathodic reaction are repeated three times as frequently as when a single-phase alternating waveform current of the same frequency is applied. Even when the surface roughening process is performed, chatter marks, which are stripes in the width direction, are less likely to occur.

FIG. 2 is a schematic cross-sectional view of another example of an electrolytic surface roughening treatment apparatus having a flat type AC electrolytic cell suitably used in the present invention. 2, the same reference numerals as those in FIG. 1 indicate the same elements as those shown in FIG. The electrolytic surface-roughening treatment device 102 is an electrolytic surface-roughening treatment device in which the auxiliary electrolytic cell 10 is disposed at a stage subsequent to the AC electrolytic cell 2 included in the above-described electrolytic surface-roughening treatment device 100. The auxiliary electrolytic cell 10 has a box shape with an open top, and has
A plate-shaped auxiliary electrode 12 is provided in parallel with the transport surface T of the aluminum web W. In the vicinity of the upstream side wall surface and the vicinity of the downstream side wall surface of the auxiliary electrolytic cell 10, conveying rollers 14A and 14B for conveying the aluminum web W above the auxiliary electrode 12 are provided. In addition, on the upstream side above the auxiliary electrolytic cell 10, an introduction roller 1 for introducing the aluminum web W into the inside of the auxiliary electrolytic cell 10 is provided.
6A is provided, and on the downstream side above the auxiliary electrolytic cell 10, a lead-out roller 16B for outputting the aluminum web W having passed through the inside of the auxiliary electrolytic cell 10 to the outside is provided. The above-mentioned acidic aqueous solution is stored inside the auxiliary electrolytic cell 10.

The U phase, V phase and W phase of the AC power supply T _ac
U-phase, V-phase and W-phase
Between each of the phases and the auxiliary electrode 12, a thyristor T
h1, Th2 and Th3 are interposed. The thyristors Th1, Th2, and Th3 are all connected so that current flows from the AC power supply _Tac toward the auxiliary electrode 12 at the time of ignition. Therefore, the thyristors Th1, T
Regardless of which of h2 and Th3 is fired, the anode current flows through the auxiliary electrode 12, so that the thyristor Th
1, by the Th2 and Th3 phase control, it is possible to control the current value of anode current flowing to the auxiliary electrode 12, thus, it is possible to control the values of Q _c / Q _a.

FIG. 3 is a schematic cross-sectional view of an example of an electrolytic surface-roughening apparatus having a radial AC electrolytic cell suitably used in the present invention. The electrolytic surface-roughening treatment device 104 includes an AC electrolytic cell 20 having an AC electrolytic cell main body 22 in which an acidic aqueous solution is stored, and an AC electrolytic cell 20 housed inside the AC electrolytic cell main body 22 and rotatably arranged around an axis extending in a horizontal direction. And a feed roller 24 that feeds the aluminum web W from left to right in FIG. 3 in the transport direction a.
The acidic aqueous solution described above is stored inside the AC electrolytic cell main body 22. The inner wall surface of the AC electrolytic cell main body 22 is formed in a substantially cylindrical shape so as to surround the feed roller 24, and semi-cylindrical main poles 26A and 26B are provided on the inner wall surface with the feed roller 24 interposed therebetween. Have been. The main poles 26A and 26B are divided into a plurality of small electrodes, and an insulating spacer is interposed between the small electrodes. The small electrode can be formed using, for example, graphite or a metal, and the spacer can be formed, for example, from a vinyl chloride resin. Spacer thickness is 1 to 1
It is preferably 0 mm. Further, although simplified in FIG. 3, in each of the main electrodes 26A and 26B, each of the small electrodes divided by the spacer is connected to the AC power supply _Tac .

In the upper part of the AC electrolytic cell 20, an opening 22A for introducing and leading out the aluminum web W into the AC electrolytic cell main body 22 is formed. In the vicinity of the opening 22A in the AC electrolytic cell main body 22, a liquid supply nozzle 28A for replenishing the AC electrolytic cell main body 22 with an acidic aqueous solution is provided. Also, a liquid supply nozzle 28B is provided separately. In the vicinity of the opening 22A above the AC electrolytic cell 20, a group of upstream guide rollers 30A for guiding the aluminum web W into the AC electrolytic cell main body 22 and electrolytic roughening treatment in the AC electrolytic cell main body 22 are performed. A group of downstream guide rollers 30B for guiding the aluminum web W to the outside is provided.

In the AC electrolytic cell 20, an overflow tank 32 is provided adjacent to the downstream side of the AC electrolytic cell main body 22. The above-mentioned acidic aqueous solution is stored inside the overflow tank 32. The overflow tank 32 has a function of temporarily storing the acidic aqueous solution overflowing from the AC electrolytic cell main body 22 and maintaining the level of the acidic aqueous solution in the AC electrolytic tank main body 22 at a constant level.

An auxiliary electrolytic cell 34 is provided between the AC electrolytic cell main body 22 and the overflow cell 32. Auxiliary electrolytic cell 34
Is shallower than the AC electrolytic cell main body 22, and the bottom surface 34A is formed in a planar shape. A plurality of columnar auxiliary electrodes 36 are provided on the bottom surface 34A. The above-mentioned acidic aqueous solution is stored inside the auxiliary electrolytic cell 34. The auxiliary electrode 36 is preferably formed of a highly corrosion-resistant metal such as platinum, ferrite, or the like. The auxiliary electrode 3
6 may be plate-shaped. The auxiliary electrode 36 is connected to an AC power source T
_The thyristor Th4 is connected in parallel with the main pole 26B on the side of the _ac where the main pole 26B is connected.
There are connected as a current flows to the auxiliary electrode 36 from the side of the AC power source T _ac during ignition. Also, the side main pole 26A in an alternating current power source T _ac is connected, it is connected to the auxiliary electrode 36 through the thyristor Th5. Thyristor Th5 is also connected to a current flows from the side where the main pole 26A is connected in an alternating current power source T _ac upon ignition an auxiliary electrode 36. The anode current flows through the auxiliary electrode 36 regardless of which of the thyristors Th4 and Th5 is fired. Therefore, by controlling the phases of the thyristors Th4 and Th5, the current value of the anode current flowing through the auxiliary electrode 36 can be controlled, and therefore, the value of Q _c / Q _a can also be controlled.

The operation of the electrolytic surface roughening treatment device 104 will be described below. From the left side in FIG.
The aluminum alloy plate W guided to 0 is first guided to the AC electrolytic cell main body 22 by the upstream guide roller 30A. Then, the paper is sent from the left to the right in FIG.
Is guided into the auxiliary electrolytic cell 34 by the above. Inside the AC electrolytic cell main body 22 and the auxiliary electrolytic cell 34, the aluminum web W is applied to the main electrodes 26A and 26B by the AC current applied to the main electrodes 26A and 26B and the anode current applied to the auxiliary electrode 36. The surface on the facing side is roughened, and almost uniform honeycomb pits are formed.

<Second Alkali Etching Process> In the second alkali etching process, etching is performed by bringing the aluminum alloy plate into contact with an alkaline solution.
The kind of alkali, the method of bringing the aluminum alloy plate into contact with the alkali solution, and the apparatus used therefor include those similar to those in the case of the first alkali etching treatment. The etching amount is as follows for the surface subjected to electrolytic surface roughening.
It is preferably 0.001 to 1 g / m ² . As the alkali used for the alkali solution, the same alkali as that used in the first alkali etching treatment can be used. The concentration of the alkali solution can be determined according to the etching amount, but is preferably 0.01 to 80% by mass. The temperature of the alkaline solution is preferably from 20 to 90C.
The processing time is preferably 1 to 60 seconds. In the later-described second desmutting treatment, when an acidic solution containing 100 g / L or more of sulfuric acid and having a liquid temperature of 60 ° C. or more is used, the second alkali etching treatment can be omitted.

<Second Desmut Treatment> The second desmut treatment is performed, for example, by subjecting the aluminum alloy plate to an acidic solution of 0.5 to 30% by mass of phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid or the like (aluminum ions 0.01 to 30% by mass). 5% by mass.). The method of bringing the aluminum alloy plate into contact with the acidic solution may be the same as in the case of the first desmutting treatment. In the second desmutting treatment, it is preferable to use a waste solution of a sulfuric acid solution discharged in an anodic oxidation treatment described later as the acidic solution. Further, instead of the waste liquid, a sulfuric acid concentration of 100 to 6
00 g / L, aluminum ion concentration of 1 to 10 g / L
It is also possible to use a sulfuric acid solution having a liquid temperature of 60 to 90 ° C. The liquid temperature of the second desmutting treatment is 25 to 90
C. is preferred. The processing time of the second desmutting process is preferably 1 to 180 seconds. Aluminum and aluminum alloy components may be dissolved in the acidic solution used for the second desmutting treatment.

<Anodic oxidation treatment> The aluminum alloy plate treated as described above is preferably further subjected to anodizing treatment. The anodizing treatment can be performed by a method conventionally performed in this field. Specifically, in an electrolytic solution that is an aqueous solution or a non-aqueous solution alone or in combination of two or more of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, and amidesulfonic acid, aluminum When a direct current, a pulsating flow or an alternating current is applied to the alloy plate, an anodic oxide film can be formed on the surface of the aluminum alloy plate.

At this time, at least an aluminum alloy plate,
Components normally contained in electrodes, tap water, groundwater, and the like may be contained in the electrolytic solution. Further, the second and third components may be added. As the second and third components here, for example, Na, K, Mg, Li, Ca,
Ti, Al, V, Cr, Mn, Fe, Co, Ni, C
ions of metals such as u and Zn; cations such as ammonium ion; nitrate ion, carbonate ion, chloride ion, phosphate ion, fluoride ion, sulfite ion, titanate ion, silicate ion, borate ion, etc. Anions are mentioned, and may be contained at a concentration of about 0 to 10000 ppm.

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

When the anodic oxidation treatment is performed in an electrolytic solution containing sulfuric acid, a direct current or an alternating current may be applied to the aluminum alloy plate. When a direct current is applied to the aluminum alloy plate, the current density is 1 to 60 A
/ Dm ² , and more preferably 5 to 40 A / dm ² . In the case where the anodic oxidation treatment is performed continuously, a low level of 5 to 10 A / m ² is used at the beginning of the anodic oxidation treatment so that current is not concentrated on a part of the aluminum alloy plate and so-called “burn” does not occur. It is preferable to supply a current at a current density and increase the current density to 30 to 50 A / dm ² or more as the anodizing treatment proceeds. In the case where the anodic oxidation treatment is continuously performed, it is preferable to perform the anodic oxidation treatment by a liquid power supply system in which the aluminum alloy plate is supplied with power through an electrolytic solution.

As an electrode for supplying power to the aluminum alloy plate, an electrode formed of lead, iridium oxide, platinum, ferrite, or the like can be used. Among them, an electrode mainly formed of iridium oxide and an electrode in which the surface of a substrate is covered with iridium oxide are preferable. As such a substrate, it is preferable to use a so-called valve metal such as titanium, tantalum, niobium, and zirconium. Among the valve metals, titanium and niobium are preferable. Since the valve metal has relatively high electric resistance, the base material may be formed by cladding the valve metal on the surface of a core material made of copper. When a valve metal is clad on the surface of a copper core material, it is difficult to produce a base material having a complicated shape. After cladding, the base material may be assembled by combining the components.

The conditions of the anodic oxidation treatment cannot be unconditionally determined because it varies depending on the electrolytic solution to be used.
It is appropriate that the current density is 1 to 60 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 10 to 300 seconds. The anodic oxidation treatment is preferably performed so that the amount of the anodic oxide film becomes ¹ to 5 g / m ² from the viewpoint of the printing durability of the lithographic printing plate. Also,
It is preferable to carry out the process so that the difference in the amount of the anodic oxide film between the center and the vicinity of the edge of the aluminum alloy plate is 1 g / m ² or less.

<Pore Sealing> In the present invention, the aluminum alloy plate having the anodic oxide film formed thereon is brought into contact with boiling water, hot water or steam to seal the small holes (micropores) present in the anodic oxidation. A sealing treatment may be performed. These can be performed according to a known method.

<Hydrophilic treatment> After anodic oxidation treatment or pore sealing treatment, a method of dipping in an aqueous solution of an alkali metal silicate such as sodium silicate, potassium silicate, or the like, by applying a hydrophilic vinyl polymer or a hydrophilic compound. It is preferable to perform a hydrophilization treatment by a method of forming a hydrophilic undercoat layer by a method such as the above. The hydrophilization treatment with an aqueous solution of an alkali metal silicate such as sodium silicate and potassium silicate is disclosed in US Pat.
No. 4,066 and US Pat. No. 3,181,46.
It can be carried out according to the method and procedure described in the specification. The hydrophilization treatment by forming a hydrophilic undercoat layer can be performed in accordance with the conditions and procedures described in JP-A-59-101651 and JP-A-60-149491. Examples of the hydrophilic vinyl polymer used in this method include, for example, polyvinyl sulfonic acid, a sulfonic acid group-containing vinyl polymerizable compound such as p-styrenesulfonic acid having a sulfonic acid group, and a normal (meth) acrylic acid alkyl ester. A copolymer with a vinyl polymerizable compound is exemplified. Further, as the hydrophilic compound used in this method, for example, -NH
Compounds having at least one selected from the group consisting of _two groups, a -COOH group and a sulfo group are exemplified.

According to the method for manufacturing a lithographic printing plate support of the present invention described in detail above, even when a low-priced aluminum alloy plate having a low aluminum content is used, the unevenness of the surface is reduced. A uniform lithographic printing plate support can be obtained. The lithographic printing plate support obtained by the method for producing a lithographic printing plate support of the present invention is provided with a photosensitive layer as described below to form a lithographic printing plate precursor. When printing is performed, the printing performance is excellent and the plate is hardly broken.

<Photosensitive layer> A lithographic printing plate precursor is obtained by providing a photosensitive layer on the lithographic printing plate support obtained by the present invention. The photosensitive layer is not particularly limited, and examples thereof include a visible light exposure type plate making layer that is exposed with ordinary visible light and a laser exposure type plate making layer that is exposed with a laser beam such as an infrared laser beam. Hereinafter, the visible light exposure type plate making layer and the laser exposure type plate making layer will be described.

(1) Visible Light Exposure Type Plate Making Layer The visible light exposure type plate making layer can be formed of a composition containing a photosensitive resin and, if necessary, a coloring agent and the like. Examples of the photosensitive resin include a bodi-type photosensitive resin which becomes soluble in a developing solution when exposed to light, and a negative-type photosensitive resin which becomes insoluble in a developing solution when exposed to light. Examples of the positive photosensitive resin include a combination of a diazide compound such as a quinonediazide compound or a naphthoquinonediazide compound and a phenol resin such as a phenol novolak resin or a cresol-novolak resin. Examples of the negative photosensitive resin include diazo resins (for example, a condensate of an aromatic diazonium salt with an aldehyde such as formaldehyde), an inorganic acid salt of the diazo resin, and a diazo compound such as an organic acid salt of the diazo resin. And a binder such as a (meth) acrylate resin, a polyamide resin, or a polyurethane resin; a vinyl polymer such as a (meth) acrylate resin or a polystyrene resin; and a vinyl polymerizable compound such as a (meth) acrylate or styrene. Benzoin derivatives, benzophenone derivatives, thioxanthone derivatives and the like.

As the coloring agent, besides ordinary dyes, there can be used, for example, an exposed coloring dye which develops a color upon exposure, an exposure decoloring dye which becomes almost or completely colorless upon exposure. Examples of the exposure coloring dye include a leuco dye. Exposure decolorizable dyes, for example, triphenylmethane dyes, diphenylmethane dyes, oxazine dyes, xanthene dyes, iminonaphthoquinone dyes,
Azomethine dyes and anthraquinone dyes are exemplified.

The visible light exposure type plate-making layer can be formed, for example, by applying a photosensitive resin solution prepared by mixing the above-mentioned photosensitive resin and the above-mentioned coloring agent in a solvent, and then drying it. As the solvent used in the photosensitive resin solution,
Examples of the solvent include a solvent that can dissolve the photosensitive resin and has a certain degree of volatility at room temperature. Specific examples include alcohol solvents, ketone solvents, ester solvents, ether solvents, glycol ether solvents, amide solvents, and carbonate solvents.
Examples of the alcohol-based solvent include ethanol, propanol, and butanol. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, and diethyl ketone. Examples of the ester solvent include ethyl acetate, propyl acetate, methyl formate, and ethyl formate. Examples of the ether solvent include tetrahydrofuran and dioxane. Examples of the glycol ether solvent include ethyl cellosolve, methyl cellosolve, and butyl cellosolve. Examples of the amide-based solvent include dimethylformamide and dimethylacetamide. Examples of the carbonate-based solvent include ethylene carbonate, propylene carbonate, diethyl carbonate, and dibutyl carbonate.

The method of applying the photosensitive resin solution is not particularly limited, and conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, and blade coating are used. be able to.

(2) Laser exposure type plate making layer As the laser exposure type plate making layer, for example, a negative type laser plate making layer in which a portion irradiated with a laser beam remains, or a positive type laser plate making in which a portion irradiated with a laser beam is removed The main layer is a photopolymerization type laser plate making layer which is photopolymerized when irradiated with a laser beam.

The negative type laser plate making layer is composed of (A) an acid precursor which decomposes by heat or light to generate an acid, and (B) an acid crosslinkable crosslinkable by an acid generated by decomposing the acid precursor (A). It is formed using a negative type laser plate making layer forming solution in which a compound, (C) an alkali-soluble resin, (D) an infrared absorber, and (E) a phenolic hydroxyl group-containing compound are dissolved or suspended in an appropriate solvent. be able to.

As the acid precursor (A), for example, a compound such as an iminophosphate compound, which is decomposed by ultraviolet light, visible light or heat to generate a sulfonic acid, can be mentioned. In addition, compounds generally used as a photocationic polymerization initiator, a photoradical polymerization initiator, a photochromic agent, and the like can also be used as the acid precursor (A). Examples of the acid-crosslinkable compound (B) include an aromatic compound having at least one of an alkoxymethyl group and a hydroxyl group, a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, and an epoxy compound. Compounds. Examples of the alkali-soluble resin (C) include a polymer having a hydroxyaryl group in a side chain such as a novolak resin and poly (hydroxystyrene).

As the infrared absorbing agent (D), for example,
A dye that absorbs infrared light having a length of 760 to 1200 nm;
Pigments. Specifically, for example, black pigment, red
Color pigment, metal powder pigment, phthalocyanine pigment;
Azo dyes, anthraquinone dyes,
Talocyanine dyes and cyanine dyes are exemplified. Pheno
As the hydroxyl group-containing compound (E), for example,
The formula (R¹-X) _n-Ar- (OH)_m(Where R¹Is
An alkyl or alkenyl group having 6 to 32 carbon atoms;
X is a single bond, O, S, COO or CONH
Ar represents an aromatic hydrocarbon group, an alicyclic hydrocarbon group or
Is a heterocyclic group, and n and m are each independently 1 to 8
It is a number. )). That's it
Such compounds include, for example, compounds such as nonylphenol.
Alkylphenols. Negative type laser plate making layer
In the forming liquid, in addition to the above components, a plasticizer and the like are blended.
You can also.

The Boji type laser plate making layer comprises (F) an alkali-soluble polymer, (G) an alkali dissolution inhibitor, and (H)
It can be formed using a positive-type laser plate making layer forming solution in which an infrared absorber is dissolved or suspended in an appropriate solvent. As the alkali-soluble polymer (F), for example,
A phenolic polymer having a phenolic hydroxyl group such as a phenolic resin, a cresol resin, a novolak resin, a pyrogallol resin, or poly (hydroxystyrene); a polymer having a sulfonamide group in which at least a part of the monomer unit has a sulfonamide group; − (P
Active imide group-containing polymer obtained by homopolymerization or copolymerization of a monomer having an active imide group such as -toluenesulfonyl) (meth) acrylamide group.

Examples of the alkali dissolution inhibitor (G) include compounds that react with the alkali-soluble polymer (F) by heating or the like to reduce the alkali solubility of the alkali-soluble polymer (F). Specific examples include a sulfone compound, an ammonium salt, a sulfonium salt, and an amide compound. Examples of the combination of the alkali-soluble polymer (F) and the alkali dissolution inhibitor (G) include a combination of a novolak resin as the alkali-soluble polymer (F) and a cyanine dye which is a kind of a sulfone compound as the alkali dissolution inhibitor (G). Preferred examples are given. Examples of the infrared absorbing agent (H) include a squarylium dye, a pyrylium dye, carbon black, an insoluble azo dye, and an anthraquinone dye, which have an absorption region in an infrared region of a wavelength of 750 to 1200 nm and have a light / heat conversion ability. , Dyes and pigments.

The photopolymerization type laser plate making layer can be formed using (I) a photopolymerization type laser plate making layer forming solution containing a vinyl polymerizable compound having an ethylenically unsaturated bond at a molecular terminal. The photopolymerization type laser plate making layer forming liquid may optionally contain (J) a photopolymerization initiator, (K) a sensitizer, and the like. Examples of the vinyl polymerizable compound (I) include, for example, ethylenically unsaturated carboxylic acid polyvalent, which is an ester of an ethylenically unsaturated carboxylic acid such as (meth) acrylic acid, itaconic acid, and maleic acid with an aliphatic polyhydric alcohol. Esters; methylene bis (meth) acrylamide comprising the above ethylenically unsaturated carboxylic acid and a polyvalent amine; and polyethylenically unsaturated carboxylic acid amides such as xylylene (meth) acrylamide. Other examples of the vinyl polymerizable compound (I) include aromatic vinyl compounds such as styrene and α-methylstyrene; and ethylenically unsaturated carboxylic acid monoesters such as methyl (meth) acrylate and ethyl (meth) acrylate. No. As the photopolymerization initiator (J), a photopolymerization initiator generally used for photopolymerization of a vinyl monomer can be used. Examples of the sensitizer (K) include titanocene compounds, triazine compounds, benzophenone compounds, benzimidazole compounds, cyanine dyes, merocyanine dyes, xanthene dyes, and coumarin dyes.

Solvents used in the negative type laser plate making layer forming liquid, the positive type laser plate making layer forming liquid and the photopolymerization type laser plate making layer forming liquid, and the negative type laser plate making layer forming liquid and the positive type laser plate making layer As for the method of applying the forming liquid and the photopolymerization type laser plate making layer forming liquid, the solvents and coating methods described for the above photosensitive resin solution can be used. In the case of forming a photopolymerization type laser plate making layer, using a silicone compound having a reactive functional group such as a partially decomposed silane compound obtained by partially decomposing a silane compound with water, alcohol or carboxylic acid, It is preferable to treat the roughened surface of the lithographic printing plate support in advance, since the adhesion between the support and the photopolymerization type laser plate making layer is improved.

<Matte layer> On the surface of the photosensitive layer provided as described above, in order to reduce the time for evacuation during contact exposure using a vacuum printing frame and to prevent burning blur, A mat layer may be provided. Specifically, a method of providing a mat layer as described in JP-A-50-125805, JP-B-57-6582, and JP-A-61-28986 is described in JP-B-62-62337. And a method of thermally depositing such a solid powder.

<Backcoat layer> The lithographic printing plate precursor obtained as described above is provided with an organic coating on the back surface (the surface on which the photosensitive layer is not provided) so that the photosensitive layer is not damaged even when it is overlaid. A coating layer made of a molecular compound (hereinafter, also referred to as a “backcoat layer”) may be provided as necessary. As a main component of the back coat layer, at least one resin selected from the group consisting of a saturated copolymerized polyester resin, a phenoxy resin, a polyvinyl acetal resin and a vinylidene chloride copolymerized resin having a glass transition point of 20 ° C. or higher is used. Is preferred.

The saturated copolymerized polyester resin comprises a dicarboxylic acid unit and a diol unit. Examples of the dicarboxylic acid unit include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid, and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, oxalic acid, suberic acid, and sebacic acid , Malonic acid, saturated aliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid.

The back coat layer further comprises a dye or pigment for coloring, a silane coupling agent for improving adhesion to a support, a diazo resin comprising a diazonium salt,
An organic phosphonic acid, an organic phosphoric acid, a cationic polymer, a wax usually used as a slipping agent, a higher fatty acid, a higher fatty acid amide, a silicone compound composed of dimethylsiloxane, a modified dimethylsiloxane, a polyethylene powder and the like can be appropriately contained.

The thickness of the back coat layer may be basically such that the photosensitive layer is not easily damaged even without the slip sheet.
It is preferably from 0.01 to 8 μm. Thickness 0.01
If it is less than μm, it is difficult to prevent the photosensitive layer from being scratched when the lithographic printing plate precursors are handled in an overlapping manner. Also,
If the thickness exceeds 8 μm, during printing, the back coat layer swells due to chemicals used around the lithographic printing plate, causing the thickness to fluctuate, changing the printing pressure and deteriorating printing characteristics.

Various methods can be used for providing the back coat layer on the back surface of the lithographic printing plate precursor. For example, a method of dissolving the above components for the backcoat layer in an appropriate solvent and applying the solution, or applying an emulsified dispersion and applying the applied solution, followed by drying; A method of bonding to a printing plate precursor: a method of forming a molten coating with a melt extruder and bonding to a lithographic printing plate precursor. The most preferable method for securing a suitable thickness is a method in which the components for the back coat layer are dissolved in a suitable solvent, applied as a solution, and dried. In this method, an organic solvent described in JP-A-62-251739 can be used alone or as a mixture.

In the production of a lithographic printing plate precursor, either the back coat layer on the back surface or the photosensitive layer on the front surface may be provided first on the support, or both may be provided simultaneously.

The lithographic printing plate precursor thus obtained is cut into a suitable size, if necessary, exposed, developed and plate-made to obtain a lithographic printing plate. In the case of a lithographic printing plate precursor provided with a visible light exposure type plate making layer (photosensitive plate making layer), a transparent film on which a printed image is formed is exposed by irradiating it with ordinary visible light, and then developed. The plate making can be performed by performing In the case of a lithographic printing plate precursor provided with a laser-exposed type plate-making layer, plate making can be performed by irradiating various laser beams to directly write a print image to expose and then developing.

[0082]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. 1. Production of Lithographic Printing Plate Support (Examples 1-1 to 1-24 and Comparative Example 1-1) As shown in Table 2, each aluminum alloy plate having the composition shown in Table 1 was subjected to each surface treatment. To obtain a lithographic printing plate support. The surface treatments shown in Table 2 are mechanical surface roughening treatments,
An alkali etching treatment, a first desmutting treatment, an electrochemical graining treatment, a second alkali etching treatment, a second desmutting treatment, an anodic oxidation treatment and a hydrophilic treatment are combined in this order. For details of each process,
It is as follows. Note that, after each treatment, washing with water was performed by spraying, and after each treatment and washing, liquid was removed with a nip roller.

(1) Mechanical Roughening Treatment Using an apparatus as shown in FIG. 4, a suspension of an abrasive (silica sand) having an average particle diameter of 20 μm and water is polished into a polishing slurry liquid (specific gravity: 1. As 12), a mechanical surface roughening treatment was performed by a rotating roller-shaped nylon brush while supplying the aluminum alloy plate to the surface with a spray pipe. In FIG.
1 is an aluminum alloy plate, 52 and 54 are roller-like brushes, 53 is a polishing slurry liquid, and 55, 56, 57 and 58 are support rollers. The nylon brush material is 6.
10 nylon, hair length 60mm, hair diameter 0.295
mm. The nylon brush was planted so as to be dense by making holes in a stainless steel cylinder of φ300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) below the brush was 300 mm. The brush roller controlled the load of the drive motor for rotating the brush against the load before pressing the brush roller against the aluminum alloy plate, and the difference was 1.5 kW. The direction of rotation of the brush was the same as the direction of movement of the aluminum alloy plate. The number of rotations of the brush was 250 rpm. Arithmetic average roughness after mechanical surface roughening treatment (JIS B0601-1)
Cutoff value 0.3 mm, evaluation length 3 according to 994
mm. ) Were in the range of 0.3 to 0.5 μm.

(2) First Alkali Etching Treatment The aluminum alloy plate was immersed in an aqueous solution (solution temperature: 70 ° C.) containing 27% by mass of caustic soda and 6.5% by mass of aluminum ions to carry out a first alkali etching treatment. Then, the treated surface of the aluminum alloy plate was melted in an amount shown in Table 2.

(3) First Desmut Treatment The first desmut treatment was performed by immersing the aluminum alloy plate in an acidic aqueous solution at a liquid temperature of 35 ° C. for the treatment time shown in Table 2. As the acidic aqueous solution, a waste solution of the acidic aqueous solution used in the next electrochemical graining treatment was used. (4) Electrochemical surface-roughening treatment 15 g of 68% by mass nitric acid, 63 g of aluminum nitrate, and a compound capable of forming a complex with copper of the type shown in Table 2 were added per 1 L of water in the amounts shown in Table 2. Electrochemical graining treatment was performed using 50 L of an acidic aqueous solution (liquid temperature 50 ° C.) obtained by the above method. The electrochemical graining treatment is performed at a frequency of 60H.
Using a trapezoidal alternating current of z and duty 0.5, the time TP until the current value in the alternating current reaches zero or a positive or negative peak is 0.8 msec, and the current density I at the peak of the alternating current in the anode cycle side is I _ap 50A / d
m ² , the current density I _cp at the peak on the cathode cycle side is 47.5 A / dm ^2, and the quantity of electricity from the start to the end of the electrolytic surface roughening treatment is expressed by the total sum when the aluminum alloy plate is the anode. Table 2 shows the quantity of electricity at the anode Q _a
And the ratio Q _c / Q _a a cathode time electricity Q _c 0.95, was carried out.

(5) Second Alkali Etching Treatment An aluminum alloy plate was treated with an aqueous solution containing 5% by mass of caustic soda and 0.5% by mass of aluminum ions (liquid temperature of 3%).
(0 ° C.), a second alkali etching treatment was performed, and the treated surface of the aluminum alloy plate was dissolved in an amount shown in Table 2. (6) Second desmut treatment The aluminum alloy plate was immersed in an acidic aqueous solution having the liquid temperature shown in Table 2 for 5 seconds to perform a second desmut treatment. However, in Examples 1-23 and 1-24, the immersion time was 40 seconds. As the acidic aqueous solution, a waste solution of the acidic aqueous solution used in the next electrochemical graining treatment was used.

(7) Anodizing treatment An acidic aqueous solution (solution temperature: 35 ° C.) prepared by adding aluminum sulfate to sulfuric acid having a sulfuric acid concentration of 170 g / L to adjust the aluminum ion concentration to 5 g / L was used. Anodizing treatment was carried out at a current density of 2 A / dm ^{2 so} that the amount of the anodic oxide film was as shown in Table 2. (8) Hydrophilization treatment An aluminum alloy plate was immersed in an aqueous solution of No. 3 sodium silicate for 7 seconds to perform a hydrophilization treatment. The concentration and temperature of the aqueous solution are shown in Table 2.

2. Surface Shape of Lithographic Printing Plate Support The surface shape of each lithographic printing plate support obtained in each Example and Comparative Example was observed at a magnification of 2000 using a scanning electron microscope, and honeycomb pits formed on the surface were observed. Was evaluated for uniformity. The results are shown in Table 2. In addition, the evaluation was expressed as A when the surface unevenness was extremely uniform, B when the uniformity was good, and C when the unevenness was uneven.

3. Production of lithographic printing plate precursors (Examples 2-1 and 2-2) Examples 1-21 and 1
The photosensitive layer A was formed on the surface of each lithographic printing plate support obtained in -23 by the following steps to obtain each lithographic printing plate precursor.

In forming the photosensitive layer A, an undercoat layer was previously formed. The undercoat layer was formed by applying an undercoat liquid having the following composition and drying at 80 ° C. for 30 seconds.
The coating amount after drying was 10 mg / m ² . <Undercoat liquid composition>-0.05 parts by mass of dihydroxyethyl glycine-94.95 parts by mass of methanol-5.00 parts by mass of water

A photosensitive resin solution having the following composition is applied on the undercoat layer, and dried at 100 ° C. for 2 minutes to form a photosensitive layer A (positive visible light exposure type plate-making layer). The original plate was obtained. The coating amount after drying was 2.5 g / m ² . <Photosensitive resin solution composition>-0.73 g of an ester compound of naphthoquinone-1,2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin-2.00 g of cresol-novolak resin-Dye (oil blue # 603, Orient Chemical 0.04 g ・ Ethylene dichloride 16 g ・ 2-Methoxyethyl acetate 12 g

(Comparative Example 2-1) A photosensitive layer A was formed on the surface of the lithographic printing plate support obtained in Comparative Example 1-1 in the same process as in Example 2-1. I got the original.

(Examples 2-3 and 2-4) Example 1
On the surface of each lithographic printing plate support obtained in Nos. 16 and 1-22, a photosensitive layer B was formed in the following steps to obtain each lithographic printing plate precursor.

In forming the photosensitive layer B, an undercoat layer was previously formed. The undercoat layer was formed by applying an undercoat liquid having the following composition and drying at 100 ° C. for 10 seconds. The coating amount after drying was 0.05 g / m ² . <Undercoat liquid composition> Mainly methyl methacrylate / ethyl acrylate / 2-acrylamide-2-methylpropane sodium sulfonate copolymer (monomer ratio: 50/3)
0/20 (molar ratio), average molecular weight 60,000).

A photosensitive resin solution having the following composition was applied on the undercoat layer and dried at 120 ° C. for 40 seconds to form a photosensitive layer B
(A negative type visible light exposure type plate making layer) was formed to obtain a negative type lithographic printing plate precursor. The coating amount after drying is 2.0 g / m
^{Was 2} . <Composition of photosensitive resin solution>-0.87 g of 2-hydroxyethyl methacrylate copolymer (I) described in Example 1 of U.S. Patent No. 4,123,276-p-diazodiphenylamine and 2-Methoxy 4-hydroxy-5-benzoylbenzenesulfonate 0.1 g of a condensate with paraformaldehyde Dye (oil blue # 603, manufactured by Orient Chemical Industries) 0.03 g Methanol 6 g 2-Methoxyethanol 4g

(Examples 2-5 to 2-8) Examples 1-4,
The photosensitive layer C was formed on the surface of each of the lithographic printing plate supports obtained in 1-16, 1-17 and 1-24 by the following steps to obtain each lithographic printing plate precursor.

In forming the photosensitive layer C, an undercoat layer was formed in advance. The undercoat layer was formed by applying an undercoat liquid having the following composition and drying at 80 ° C. for 30 seconds.
The coating amount after drying was 10 mg / m ² . <Undercoat liquid composition> • 0.5 g of β-alanine • 95 g of methanol • 5 g of water

A positive laser plate-making layer forming solution having the following composition was applied on the undercoat layer using a wire bar.
To form a photosensitive layer C (positive laser plate making layer), thereby obtaining a positive type lithographic printing plate precursor. The coating amount after drying was 1.8 g / m ² . <Positive laser plate making layer forming liquid composition>-0.7 g of alkali-soluble polymer compound A obtained by the following method-2,6-dimethylene- (4,5-naphthalene-1,2,3-trimethylpyro) ) -4-monochloro-5,6-propane-heptene-methylbenzenesulfonate (cyanine dye (alkaline dissolution inhibitor)) 0.1 g ・ tetrahydrophthalic anhydride 0.05 g ・ Victor Pure Blue BOH 1-naphthalenesulfonic acid anion dye 0.02 g ・ Fluorine surfactant (Megafac F177, manufactured by Dainippon Ink and Chemicals, Inc.) 0.05 g ・ γ-butyl lactone 8 g ・ Methyl ethyl ketone 8 g ・ 1-methoxy-2 -4 g of propanol

<Production of alkali-soluble polymer compound A>
500m with stirrer, cooling pipe and dropping funnel
31.0 g of methacrylic acid (0.
36 mol), 39.1 g (0.26) of ethyl chloroformate
mol) and 200 mL of acetonitrile, the mixture was stirred while cooling in an ice-water bath, and 36.4 g (0.36 mol) of triethyleneamine was added using a dropping funnel over about 1 hour. After the dropwise addition, the mixture was stirred at room temperature for 30 minutes, and 51.7 g of p-aminobenzenesulfonamide was added.
(0.30 mol), and the mixture was stirred for 1 hour while warming to 70 ° C. in an oil bath. This is slurried in water,
The solid was collected by filtration to obtain a white solid of N- (p-aminosulfenyl) methacrylamide. 5.04 g of this
(0.021 mol) and ethyl methacrylate 2.05
g (0.018 mol), acrylonitrile 1.11 g
(0.021 mol) and 20 g of N, N-dimethylacetamide in a three-necked flask, heated to 65 ° C., mixed with 0.15 g of “V-65” manufactured by Wako Pure Chemical Industries, Ltd. It was time stirring. To this, 5.04 g of N- (p-aminosulfophenyl) methacrylamide (0.04 g) was added.
021 mol) and 2.05 g of ethyl methacrylate (0.
018 mol), acrylonitrile 1.11 g (0.0
21 mol), a mixture of 20 g of N, N-dimethylacetamide and 0.15 g of “V-65” was added dropwise over 2 hours. After the reaction was completed, 40 g of methanol was added, and the mixture was mixed for 30 minutes. Drying gives a white alkali-soluble polymer compound A (molecular weight 53,000) 15
g was obtained.

(Examples 2-9 and 2-10) Example 1
The photosensitive layer D was formed on the surface of each lithographic printing plate support obtained in -21 and 1-23 by the following steps to obtain each lithographic printing plate precursor.

In forming the photosensitive layer D, an undercoat layer was previously formed. The undercoat layer was formed by applying an undercoat liquid having the following composition and drying at 80 ° C. for 30 seconds.
The coating amount after drying was 11 mg / m ² . <Undercoat liquid composition>-0.1 g of beta-alanine-0.05 g of phenylphosphonic acid-40 g of methanol-60 g of water

A negative laser plate making layer forming solution having the following composition was applied on the undercoat layer using a wire bar.
To form a photosensitive layer D (negative type laser plate making layer), thereby obtaining a negative type lithographic printing plate precursor. The coating amount after drying was 1.5 g / m ² . <Negative laser plate making layer forming liquid composition>-Nonylphenol (acid-crosslinkable compound) 0.05 g-2,4,6-trimethoxydiazonium-2,6-dimethylbenzenesulfonate (acid precursor) 0.3 g- 0.5 g of poly (p-hydroxystyrene) (alkali-soluble resin) 1.5 g of 2,6-dimethylene- (4,5-naphthalene-1) , 2,3-trimethylpyrrol) -4-monochloro-5,6-propane-heptene-methylbenzenesulfonate (cyanine dye (infrared absorbing agent)) 0.07 g Eisenspirone blue C-RH (Hodogaya Chemical Co., Ltd.) 0.035 g ・ Fluorine surfactant (MegaFac F177, manufactured by Dainippon Ink and Chemicals, Inc.) 0.01 g ・ Methyl ethyl ketone 12 g ・ Methanol 10g ・ 1-Methoxy-2-propanol 8g

<Production of Crosslinking Agent A> 1- [α-methyl-α
-(4-hydroxyphenyl) ethyl] -4- [α, α
-Bis (4-hydroxyphenyl) ethyl] benzene was reacted with formalin in an aqueous solution of sodium hydroxide. The obtained reaction solution was acidified with sulfuric acid, crystallized, and had a purity of 92% by mass.
Was obtained.

4. Exposure and development of the lithographic printing plate precursor Each lithographic printing plate precursor obtained as described above was exposed and developed as described below to obtain each lithographic printing plate. (1) Lithographic printing plate precursor having photosensitive layer A The lithographic printing plate precursor having the photosensitive layer A was exposed through a transparent positive film in a vacuum printing frame for 50 seconds from a distance of 1 m with a 3 kW metal halide lamp. Thereafter, development was performed using a 5.26% by mass aqueous solution (pH 12.7) of sodium silicate having a molar ratio of SiO ₂ / Na ₂ O of 1.74. Thereafter, gum was pulled.

(2) Lithographic printing plate precursor having photosensitive layer B The lithographic printing plate precursor having the photosensitive layer B was passed through a transparent negative film in a vacuum furnace at a distance of 0.7 m to 3 kW.
Was exposed for 50 seconds using a metal halide lamp.
Thereafter, development was performed using a developer having the following composition. afterwards,
I gummed. <Developer composition>-450 g of benzyl alcohol-150 g of triethanolamine-10 g of monoethanolamine-150 g of sodium t-butylnaphthalenesulfonate-30 g of sodium sulfite-8420 g of ion-exchanged water

(3) Lithographic printing plate precursor having photosensitive layer C The lithographic printing plate precursor having the photosensitive layer C was subjected to main operation speed using a semiconductor laser having an output of 500 mW, a wavelength of 830 nm, and a beam diameter of 17 μm (1 / e ² ). After exposure at 5 m / sec, development was performed for 30 seconds using an alkaline developer having the following composition.
A lithographic printing plate was obtained. <Alkaline developer composition>-2.8% by mass of caustic soda-2.0% by mass of silica-Nonionic surfactant (Pluronic PE-310)
0, BASF) 0.5% by mass ・ Water 94.7% by mass

(4) Lithographic printing plate precursor having photosensitive layer D The lithographic printing plate precursor having photosensitive layer D was subjected to main operation speed using a semiconductor laser having an output of 500 mW, a wavelength of 830 nm, and a beam diameter of 17 μm (1 / e ² ). After exposure at 5 m / sec, the resultant was immersed in a 1: 8 water diluent of a developer PD-4 (manufactured by Fuji Photo Film Co., Ltd.) for 30 seconds for development to obtain a lithographic printing plate.

5. Evaluation of lithographic printing plate Each lithographic printing plate obtained as described above was subjected to a printing test under the following conditions, and the printing performance was visually evaluated by the degree of adhesion of the ink to the blanket. <Printing test> A Harris printing machine manufactured by Aurelia Co., Ltd. was used as the printing machine, and isopropanol was added to EU-3 (1: 100) manufactured by Fuji Photo Film Co., Ltd. as fountain solution at 10% by mass of the total. Using the liquid added as described above, and using, as an ink, Claf G (S) red manufactured by Dainippon Ink and Chemicals,
Printing was done. After printing 1,000 sheets, the printing performance (the degree of adhesion of the ink to the blanket) was evaluated.

The lithographic printing plates obtained by making the lithographic printing plate precursors of Examples 2-1 to 2-10 hardly adhered any ink to the blanket, and had good printing performance. On the other hand, the lithographic printing plate obtained by making the lithographic printing plate precursor of Comparative Example 2-1 had a large amount of ink attached to the blanket, was poor in printing performance, and was unsuitable as a printing plate.

[0110]

[Table 1]

[0111]

[Table 2]

[0112]

[Table 3]

According to the method for producing a lithographic printing plate support of the present invention, whether the aluminum content of the aluminum alloy plate is low or high, or the Cu content is high or low, It can be seen that a lithographic printing plate support having extremely uniform honeycomb pits on the surface can be obtained without strictly adjusting the processing conditions (Examples 1-1 to 1-2).
4). Therefore, even when the beverage can is scrapped and an aluminum alloy plate obtained by recycling is used (Examples 1-18 to 1-24), it is possible to obtain a lithographic printing plate support having extremely uniform honeycomb pits on the surface. Can be. Further, the lithographic printing plate support obtained by the method for producing a lithographic printing plate support of the present invention was provided with a conventional type visible light exposure type plate-making layer (Examples 2-1 to 2-).
4) and a case where a laser plate-making layer is provided (Example 2-5)
In any one of 2 to 10), when a lithographic printing plate is used, the printing performance is excellent. And, from a lithographic printing plate support using an aluminum alloy plate having a high Cu content such as an aluminum alloy plate obtained by scrapping a beverage can and recycling, a lithographic printing plate excellent in printing performance can be obtained. (Examples 2-1, 2-2, 2-4 and 2-8 to 2-10).

On the other hand, in the production of a lithographic printing plate support, an aluminum alloy plate having a high Cu
When the electrochemical surface-roughening treatment is performed using an acidic aqueous solution containing no compound capable of forming a complex with u, the honeycomb pits on the surface of the resulting lithographic printing plate support are non-uniform. The printing performance of a lithographic printing plate is also poor (Comparative Examples 1-1 and 2-1).

[0115]

According to the method for producing a lithographic printing plate support of the present invention, even when an aluminum alloy plate having a low aluminum content and a high Cu content is used, the honeycomb pits on the surface are uniform. Thus, a lithographic printing plate support having excellent printing performance when formed into a lithographic printing plate can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an electrolytic surface roughening treatment apparatus including a flat AC electrolytic cell used in the present invention.

FIG. 2 is a cross-sectional view showing another example of an electrolytic surface roughening treatment apparatus including a flat AC electrolytic cell used in the present invention.

FIG. 3 is a cross-sectional view showing an example of an electrolytic surface roughening treatment device provided with a radial type AC electrolytic cell used in the present invention.

FIG. 4 is a side view showing the concept of a brush graining process used for mechanical roughening processing in the present invention.

[Explanation of symbols]

2, 20 AC electrolytic cell 4A, 4B, 4C, 26A, 26B Main electrode 6A, 6B, 14A, 14B Conveying roller 8A, 16A Introducing roller 8B, 16B Outgoing roller 10, 34 Auxiliary electrolytic cell 12, 36 Auxiliary electrode 22 AC electrolysis Tank main body 22A Opening 24 Feed roller 28A, 28B Liquid supply nozzle 30A Upstream guide roller 30B Downstream guide roller 32 Overflow tank 34A Bottom of auxiliary electrolytic tank 51 Aluminum alloy plate 52, 54 Roller brush 53 Polishing slurry liquid 55, 56, 57, 58 Support rollers 100, 102, 104 Electrolytic surface-roughening treatment device a Transport direction T Transport surface _Tac power supply Th1, Th2, Th3, Th4, Th5 Thyristor W Aluminum web

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C25F 3/04 C25F 3/04 A 3/20 3/20 G03F 7/00 503 G03F 7/00 503 7 / 09 501 7/09 501 (72) Inventor Akio Uesugi 4000F, Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. EA02 EA04 FA16 GA03 GA05 GA06 GA08 GA09

Claims (2)

[Claims] 1. A method for producing a lithographic printing plate support, wherein an aluminum alloy plate is subjected to a surface treatment including an electrochemical surface roughening treatment to obtain a lithographic printing plate support. A lithographic plate characterized in that the Cu content is 0.001 to 1% by mass and the electrochemical graining treatment is performed in an acidic aqueous solution containing a compound capable of forming a complex with Cu. A method for producing a printing plate support. 2. The method according to claim 1, wherein the aluminum alloy plate is made of Fe, Si,
2. The aluminum alloy according to claim 1, containing three or more elements selected from the group consisting of Cu, Mg, Mn, Zn, Cr and Ti in the following range, and having an aluminum content of 95 to 99.4 mass%. A method for producing a support for a lithographic printing plate. F
e: 0.20 to 1.0% by mass, Si: 0.10 to 1.0% by mass, Cu: 0.03 to 1.0% by mass, Mg: 0.1 to 1.5% by mass, Mn: 0.1 to 1.5% by mass, Zn: 0.03 to 0.5% by mass, Cr: 0.005 to 0.1% by mass, Ti: 0.01 to 0.5% by mass