JP2002160466A - Support for lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support for a printing plate having excellent adhesive properties with and a plate wear resistance by using a low-cost raw material without providing an expensive intermediate layer and without uniform roughing treatment. SOLUTION: The support for the printing plate comprises an aluminum alloy plate containing an aluminum content of 95 to 99.4 wt.% and executed by at least roughing and anodizing. Such a support preferably contains at least a total sum of Si and Mn of 0.5 wt.% or more, and Cu of 0.05 wt.% or more. Further, it is preferable that intermetallic compounds having a diameter of 0.1 μm or more exist at 5,000 to 35,000 pieces/mm2 on a part of the roughed surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate support, and more particularly, to a lithographic printing plate which can significantly reduce raw material costs, has fine crystal grains, has excellent surface quality, and has excellent printing durability. Related to a support for use.

[0002]

2. Description of the Related Art Conventionally, a lithographic printing plate support is manufactured by subjecting one or both surfaces of an aluminum alloy plate to a surface roughening treatment and then performing an anodizing treatment to improve abrasion resistance. You. A lithographic printing plate precursor is produced by providing a photosensitive layer on this lithographic printing plate support. Further, in order to shorten the vacuum adhesion time during plate making, fine irregularities called mat layers may be provided on the surface of the photosensitive layer.

The lithographic printing plate precursor manufactured as described above is subjected to plate making processes such as image exposure, development, washing with water, etc., to obtain a lithographic printing plate. The method of image exposure is such that a lithographic film on which an image has been printed is brought into close contact with it and exposed to light to make a difference between the image area and the non-image area, using a laser, or directly projecting an image. A method of writing a difference between an image portion and a non-image portion by writing the image portion or the non-image portion, or the like is used.

In the development process after image exposure, the undissolved photosensitive layer forms an image area as an ink receptor, and the portion where the photosensitive layer has been dissolved and removed is exposed to the underlying aluminum alloy or anodic oxide film. Then, a non-image portion is formed as a water receptor. After the development, if necessary, a hydrophilization treatment, gumming, burning treatment and the like may be performed.

[0005] The lithographic printing plate is mounted on a cylindrical plate cylinder of a printing press and supplies ink and dampening solution to the plate cylinder. Water adheres to the non-image part of the nature. After transferring the ink in the image area to the blanket cylinder, an image is printed on the paper from the blanket cylinder. Here, if the adhesion between the image area and the photosensitive layer is insufficient, there is a problem that printing is completed with a small number of sheets. As a method for improving the adhesion between the image and the photosensitive layer, a method of providing an intermediate layer between the aluminum alloy plate and the photosensitive layer, a method of uniformly roughening the aluminum alloy plate, and the like are known. .

As the intermediate layer, JP-A-60-14949
No. 1 and amino acids and salts thereof (N
alkali metal salts such as a salt and K salt; ammonium salt; hydrochloride; oxalate; acetate; phosphate;
Amines having a hydroxyl group and their salts (hydrochloride; oxalate; phosphate;
Etc.) and a compound having an amino group and a phosphonic acid group or a salt thereof disclosed in JP-A-63-165183 can be used as an intermediate layer for undercoating.
Further, a compound having a phosphonic acid group disclosed in JP-A-4-282637 can be used as the intermediate layer. Further, after the alkali metal silicate treatment, a method disclosed in Japanese Patent Application No. 9-264309 (Japanese Patent Application Laid-Open No.
It has been known to use a polymer compound containing an acid group and an onium group described in JP-A No. 37 (1999) as an intermediate layer. However, the method of providing the intermediate layer for adhesion between the rough surface and the photosensitive layer naturally has a problem that the production cost for providing the intermediate layer increases.

On the other hand, in order to perform the surface roughening treatment uniformly,
There is known a method of limiting an alloy component contained in an aluminum alloy and having a large effect on surface roughening.

[0008] Many proposals have been disclosed as methods for limiting alloy components. For example, regarding the JIS 1050 material, the inventors of the present invention disclosed in JP-A-59-15386.
No. 1, JP-A-61-51395, JP-A-62
JP-A-146694, JP-A-60-215725, JP-A-60-215726, and JP-A-60-2
No. 15727, Japanese Unexamined Patent Publication No. Sho 60-215728,
JP-A-61-272357, JP-A-58-117
No. 59, JP-A-58-42493, JP-A-5-42493
JP-A-8-222254, JP-A-62-148295, JP-A-4-254545, JP-A-4-16
The technology is disclosed in Japanese Patent Publication No. 5041, Japanese Patent Publication No. 3-68939, Japanese Patent Laid-Open Publication No. 3-234594, Japanese Patent Publication No. 1-47545, and Japanese Patent Laid-Open Publication No. 62-140894. In addition, Japanese Patent Publication No. 1-35910, Japanese Patent Publication No. 5
No. 5-28874 is also known. JIS 10
Regarding the 70 materials, the present inventors disclosed in Japanese Patent Application Laid-Open No.
1264, JP-A-7-305133, JP-A-8-49034, JP-A-8-73974, JP-A-8-108559, and JP-A-8-10859.
The technology is disclosed in Japanese Patent No. 92679.

Regarding Al-Mg based alloys, the present inventors have disclosed Japanese Patent Publication No. 62-5080 and Japanese Patent Publication No.
No. 60823, JP-B-3-61753, JP-A-60-203496, JP-A-60-20349
7, JP-B-3-11635, JP-A-61-1
No. 274993, JP-A-62-23794,
JP-A-63-47347, JP-A-63-4734
No. 8, JP-A-63-47349, JP-A-64
-61293, JP-A-63-135294, JP-A-63-87288, and JP-B-4-733.
No. 92, Japanese Patent Publication No. 7-100844, Japanese Unexamined Patent Publication No.
JP-A-2-149856, JP-B-4-73394, JP-A-62-181191, JP-B5-76
No. 530, JP-A-63-30294 and JP-B-6-37116 disclose the technology. Also,
JP-A-2-215599, JP-A-61-2017
No. 47 is also known.

Regarding Al-Mn alloys, the present inventors disclosed in Japanese Patent Application Laid-Open Nos. 60-230951 and
The technology is disclosed in JP-A-306288 and JP-A-2-293189. In addition, Japanese Patent Publication No. 54-4228
No. 4, Japanese Patent Publication No. 4-19290, Japanese Patent Publication No. 4-1
Nos. 9291, 4-19292, JP-A-61-35995, JP-A-64-51992, US5009722, US5028276, and JP-A-4-226394 are also known.

Regarding the Al-Mn-Mg alloy, the present inventors have disclosed the technology in Japanese Patent Application Laid-Open Nos. 62-86143 and 3-222796. Also, Japanese Patent Publication No. Sho 63-60824 and Japanese Patent Application Laid-open No. Sho 60-63
346, JP-A-60-63347, EP2
23737, JP-A-1-283350, US48
18300, BR1222777 and the like are also known.

Regarding Al-Zr-based alloys, the present inventors have disclosed Japanese Patent Publication No. 63-15978 and Japanese Patent Laid-Open Publication
The technology is disclosed in JP-A-51395. Also, JP-A-63-143234 and JP-A-63-14323.
No. 5 is also known. Regarding Al-Mg-Si alloys, BR14221710 and the like are also known.

[0013] However, each of these methods imposes restrictions on the aluminum material, and has a disadvantage in that the degree of freedom in material selection is reduced and expensive new ingots and expensive predetermined alloying elements are required.

For these various alloys, usually, a raw material mainly composed of aluminum is melted, a predetermined metal is added thereto to form a molten aluminum alloy of a predetermined alloy component, and the molten aluminum alloy is subsequently subjected to a cleaning treatment. It is manufactured by casting. In the cleaning treatment, a flux treatment for removing unnecessary gas such as hydrogen in the molten metal; a degassing treatment using Ar gas, Cl gas, etc .; a so-called rigid media filter such as a ceramic tube filter and a ceramic foam filter. And filtering using a filter using alumina flakes, alumina balls, or the like as a filter material, a glass cloth filter, or the like; a process combining degassing and filtering; and the like. These cleaning treatments are desirably performed in order to prevent defects due to foreign matters such as nonmetallic inclusions and oxides in the molten metal and defects due to gas dissolved in the molten metal.

As described above, casting is performed using the molten metal subjected to the cleaning treatment. Regarding the casting method, DC
There are a method using a fixed mold represented by a casting method and a method using a driving mold represented by a continuous casting method.

In the case of the DC casting method, the cooling rate is 1 to
It is set in the range of 300 ° C./sec. In this process, some of the alloying elements described above are dissolved in aluminum, but components that cannot be completely dissolved in aluminum form various intermetallic compounds and remain in the ingot. In the DC casting method, an ingot having a thickness of 300 to 800 mm can be manufactured, and the ingot is subjected to face milling according to a conventional method, and is cut from the surface layer by 1 to 30 mm, preferably 1 to 10 mm. Thereafter, a soaking process is performed as necessary. By performing the soaking process,
Among the intermetallic compounds, unstable ones change to more stable compounds, and some dissolve in aluminum. The remaining intermetallic compound is then hot-rolled,
In the process of performing cold rolling, the diameter is reduced or dispersed, but the type hardly changes. That is, it remains on the aluminum alloy plate which is the support for the lithographic printing plate.

A heat treatment called annealing may be performed before, during, or during the cold rolling. In this case, depending on the annealing heat treatment temperature, some of the elements dissolved in aluminum may precipitate as intermetallic compounds or precipitates of elemental elements. Also in this case, the precipitate remains on the aluminum alloy plate.

A predetermined thickness (0.1 to 0.1) is obtained by cold rolling.
The flatness of the aluminum alloy plate finished to 0.5 mm) may be improved by a straightening device such as a roller leveler or a tension leveler in order to improve the flatness.

As a casting method, a continuous casting method can be used. In this method, a twin-roll continuous casting method typified by a belt caster such as the Hazley method or a block caster such as the Al-Swiss method can be used. For example, when a twin roll is used, the cooling rate is 100 to 1000 ° C. /
Set to the range of seconds. On the other hand, when a twin belt is used,
The cooling rate is set in the range of 10 to 500C / sec.
In any of the methods, after casting, a predetermined thickness (0.1 to 0.5 mm) is obtained by cold rolling or a rolling process combining hot rolling and cold rolling. At this time, heat treatment can be appropriately performed. The flatness of the aluminum alloy plate finished to a predetermined thickness by cold rolling may be improved by a straightening device such as a roller leveler or a tension leveler in order to improve the flatness. These features of the continuous casting method have an advantage that the running cost is lower than that of the DC casting method because a facing step required in the DC casting method can be omitted.

Here, in order to make aluminum as a raw material into a predetermined alloy component, an aluminum lump having a purity of 99.7% or more, which is usually referred to as new metal, is used. Aluminum scrap is used. If necessary, an aluminum alloy called a master alloy containing a predetermined element is added, or a metal lump made of a predetermined metal element is added to produce an aluminum alloy material having a desired alloy component.

However, a new metal or an aluminum alloy material containing a predetermined additive element component has a disadvantage that its own cost is high. In addition, when using aluminum scrap whose alloy component is known in an aluminum manufacturing plant, there is a merit in improving the yield of raw materials, but it is not at a low cost.

In response to such a problem that the raw material cost is high, the present inventors disclosed in Japanese Patent Application Laid-Open No. 7-81260, using only an aluminum lump having a purity of 99.7% or more and containing a predetermined element. A method was proposed in which the addition of a mother alloy or metal lump was unnecessary. The present inventors have also disclosed in Japanese Patent Application Laid-Open
Japanese Patent Publication No. 05534 proposes a method of reusing a used lithographic printing plate or a lithographic printing plate that has become defective during production as an aluminum raw material.

However, even if these methods are used, an aluminum lump having an aluminum purity of 99.7% or more is not so inexpensive, and it is difficult to secure a used lithographic printing plate as a stable raw material. No practically significant effect was obtained.

In order to solve the above-mentioned problems, as a raw material, a material whose alloy component is not controlled, that is, a scrap material containing various impurities, or a market price lower than that of a new bullion, is used. It is conceivable to use a secondary metal containing an impurity element or a metal called a recycled metal. However, since these alloy components are hardly controlled, they cannot be used at all for raw materials requiring high-quality surface treatment appearance and printing performance like lithographic printing plates. In particular, since uniform surface roughening cannot be performed, there has been a problem that adhesion to the photosensitive layer is insufficient, and printing durability is poor.

[0025]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the need for providing an expensive intermediate layer, to provide uniform surface roughening, to use extremely inexpensive raw materials, and to use a photosensitive material. An object of the present invention is to provide a lithographic printing plate support having excellent adhesion to a layer and excellent printing durability.

[0026]

In view of the above-mentioned problems, as a result of intensive studies, the present inventors have found that the aluminum content is 95 to 9%.
At least 9.4 wt% of an aluminum alloy plate containing a predetermined impurity is subjected to at least surface roughening treatment and anodic oxidation treatment to provide a lithographic printing plate support excellent in adhesion to a photosensitive layer and excellent printing durability. The present inventors have found that the body can be manufactured at low cost, and arrived at the present invention. That is, the present invention provides a lithographic printing plate characterized in that <1> an aluminum alloy plate having an aluminum content of 95 to 99.4 wt% is subjected to at least roughening treatment and anodizing treatment. It is a support.

<2> characterized by containing at least 0.5 wt% or more of Si and Mn in total.
> The lithographic printing plate support described in <1>.

<3> On a part of the roughened surface, an intermetallic compound having a diameter of 0.1 μm or more is used.
<1> or <1 characterized by the presence of 0 / mm ²
2> The support for a lithographic printing plate described in <2>.

<4> The lithographic printing plate support as described in any one of <1> to <3>, containing Cu in an amount of 0.05 wt% or more.

<5> The raw material of the aluminum alloy plate contains 1% by weight of at least one of a recycled aluminum base metal and a scrap material.
4> The support for a lithographic printing plate according to any one of the above.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION The lithographic printing plate support of the present invention comprises:
An aluminum alloy plate having an aluminum content of 95 to 99.4 wt% is at least subjected to a surface roughening treatment and an anodic oxidation treatment. As a raw material of the aluminum alloy plate, at least one of a recycled aluminum metal and a scrap material is used.
It is desirable to include at least 1 wt% of the seed. As a scrap material, a used beverage can (UBC) or the like is desirable. By using such recycled metal or scrap material, it is possible to further reduce raw material costs. The surface roughening treatment includes at least an alkali etching treatment step, an electrolytic surface roughening treatment step, and a desmutting treatment step, and the desmutting treatment step includes at least an alkali treatment step and an acid treatment step with an acid. , Preferably. Hereinafter, the lithographic printing plate support of the present invention will be described in detail with reference to its production method and the like.

<< 1. Manufacturing method of lithographic printing plate support>
The lithographic printing plate support of the present invention is, for example, a web-shaped aluminum alloy plate (hereinafter, referred to as an aluminum alloy plate) made of an aluminum alloy.
This is called "aluminum strip". Prepare)
It is manufactured by subjecting it to at least a roughening treatment and an anodic oxidation treatment. Specifically, the surface roughening treatment includes:
At least (1) mechanical surface roughening treatment step and alkali etching treatment step, (2) electrolytic surface roughening treatment step,
(3) a desmutting step. After the surface roughening treatment, (4) anodizing treatment (anodizing treatment step) is performed to finally produce a lithographic printing plate support. In the surface roughening treatment in the above steps (1) and (2), both mechanical roughening treatment and electrolytic surface roughening treatment may be performed, or either one may be performed.

In practice, an aluminum raw material is cast by a conventional method, and is appropriately rolled or heat-treated to have a thickness of 0.1 to 0.7.
An aluminum alloy plate for a lithographic printing plate manufactured by preparing an aluminum alloy plate having a thickness of 2 mm and performing flatness correction as needed, is formed into an aluminum strip, and is continuously formed by the above-described processing steps (1) to (4). The lithographic printing plate is processed and wound into a coil to produce a lithographic printing plate support.

Here, the aluminum alloy which can be used in the method for producing a lithographic printing plate support of the present invention is not an aluminum lump having a purity of 99.7% or more, which is called a new metal, and it has been considered difficult to use it. Low purity aluminum blocks such as scrap aluminum material, secondary metal, recycled metal, and the like. By using a low-purity aluminum block as a raw material, a lithographic printing plate support can be manufactured at lower cost than conventional methods.

The preferred method for producing the lithographic printing plate support of the present invention is such that the aluminum content (purity) is 95 to 99.%.
An aluminum alloy plate of 4 wt% is used. If the purity is higher than 99.4 wt%, the allowable amount of impurities decreases, and the cost reduction effect decreases. If the content is lower than 95 wt%, a large amount of impurities will cause a problem such as cracking during rolling. More preferably, the purity of aluminum is 95 to 99 wt%, and still more preferably, 95 to 97 wt%.
It is.

Preferably, the aluminum alloy contains at least 0.5 wt% or more of Si and Mn in total, and more preferably 0.8 to 2.0 wt%. Si and Mn are total,
If the amount is less than 0.5 wt%, the cost reduction effect may not be exhibited. Further, Cu is at least 0.05w
The content is preferably at least t%, preferably at least 0.1 wt%. If Cu is less than 0.05 wt%,
In addition to reducing the cost reduction effect, electrolytic roughening becomes uneven due to Mn contained in a large amount of scrap material,
The occurrence of abnormal coarse grain may not be suppressed. Here, the abnormal coarse-grained grain refers to a coarse-grained grain due to one electrolytic pit once generated abnormally growing laterally.

The Si content is preferably 0.15 to 1.0 wt%. Si is JIS2000, 4000
It is an element contained in a large amount of scrap of 6000 series materials. In addition, 0.03-0.1wt% for new bullion
It is an element that is contained before and after and exists as a solid solution in aluminum or as an intermetallic compound. When heated during the manufacturing process of the lithographic printing plate support, the solid solution Si
May be precipitated as elemental Si. If the Si content is less than 0.15 wt%, the cost reduction effect will be reduced. A more preferred Si content is 0.3 to 1.0.
wt%.

The Mn content is preferably 0.1 to 1.5 wt%. Mn is an element contained in a large amount of JIS 3000-based material scrap. Especially can body
It is one of the main impurity metals contained in the scrap material because it is contained in a large amount in the material. Mn is also relatively easily dissolved in aluminum and forms an intermetallic compound with AlFeSi. If the Mn content is less than 0.1 wt%, the cost reduction effect will be reduced. A more preferred Mn content is 0.5 to 1.5 wt%, and still more preferably 1.0 to 1.
5 wt%.

The content of Cu is preferably 0.05 to 1.0 wt%. Cu is JIS2000, 4000
It is an element contained in a large amount of scrap of a system material, and relatively easily forms a solid solution in aluminum. If Cu is low, M
In addition to being unable to suppress abnormalities in electrolytic surface roughening caused by n, the scrap of raw materials must be strictly selected and the cost reduction effect due to the use of scrap may be reduced, which is not preferable. If the Cu content is less than 0.05 wt%, the cost reduction effect may be reduced. The more preferable Cu content is 0.08 to 1.0 wt%, and the particularly preferable content is 0.12 to 1.0 wt%.

As other metals, the aluminum alloy preferably contains at least three metals among Fe, Mg, Zn, Cr and Ti. The Fe content is preferably 0.3 to 1.0 wt%. Fe is an element that is contained around 0.1 to 0.2 wt% even in new ingots, has a small amount of solid solution in aluminum, and almost remains as an intermetallic compound. If it is more than 1.0 wt%, cracks are likely to occur during rolling, and if it is less than 0.3 wt%, the cost reduction effect is undesirably reduced. More preferably, the content of Fe is 0.5 to 1.0 wt%.

The Mg content is preferably 0.1 to 1.5 wt%. Mg is JIS2000, 3000
-Based, 5000-based, and 7000-based materials. Particularly, since it is contained in a large amount in the can end material, one of the main impurity metals contained in the scrap material
One. Mg is relatively easily dissolved in aluminum and forms an intermetallic compound with Si. If the Mg content is less than 0.1 wt%, the cost reduction effect will be reduced. More preferable Mg content is 0.5 to 1.5 w
t%, more preferably 1.0 to 1.5 wt%.

The Zn content is preferably 0.03 to 0.5 wt%. Zn is an element particularly contained in JIS 7000 series scrap. Relatively easy to form a solid solution in aluminum. If the Zn content is less than 0.1 wt%, the cost reduction effect will be reduced. More preferably, the Zn content is 0.06 to 0.5 wt%, particularly preferably 0.1 to 0.5 wt%.

The content of Cr is preferably 0.01 to 0.1 wt%. Cr is JIS 5000 series, 6000
Metal is an impurity metal contained in a small amount in scraps of 7000 series and 7000 series. If the Cr content is less than 0.01 wt%,
The cost reduction effect is reduced. A more preferable Cr content is 0.05 to 0.1 wt%.

The content of Ti is preferably 0.03 to 0.5 wt%. Ti is usually used as a crystal refining material.
It is an element added in an amount of 01 to 0.04 wt%. JIS5
000 series, 6000 series, and 7000 series scraps are relatively large as impurity metals. If the content of Ti is less than 0.03 wt%, the cost reduction effect is reduced. A more preferred content of Ti is 0.05 to 0.1.
3 wt%.

Hereinafter, each processing step in the method for producing a lithographic printing plate support of the present invention will be described step by step. However, the following processing steps are exemplifications, and the present invention is not limited to the contents of the following steps.

<1. Mechanical surface roughening step and alkali etching step> First, the aluminum band is mechanically roughened with brush grains using a pamistone suspension (mechanical surface roughening step). Thereafter, the aluminum strip is subjected to an alkali etching treatment with an aqueous solution of an alkali agent in order to smooth the unevenness of the surface and remove abrasive particles remaining on the surface (alkali etching treatment step). As the alkali agent used for the alkali etching treatment, caustic soda, caustic potash, sodium metasilicate, sodium carbonate, sodium aluminate, sodium gluconate and the like are preferable. The concentration of the alkali agent in the aqueous solution is preferably 0.01 to 30 wt%,
The processing temperature is 60 to 80 ° C. in order to increase the productivity.
It is preferred that The etching amount of the aluminum strip is preferably 0.1 to 15 g / m ² . The processing time is 2 seconds to 5 times depending on the etching amount.
Minutes is preferable, and 2
More preferably, it is set to 10 to 10 seconds.

The step of the mechanical graining treatment is an optional step. After the alkali etching treatment without such treatment, the aluminum band is directly subjected to electrolytic graining treatment, and the subsequent treatment is performed. May be performed. Further, in order to remove the smut formed on the surface of the aluminum strip after the alkali etching treatment, a desmut treatment with nitric acid (nitric acid treatment) may be performed.

<2. Electrolytic surface-roughening process> In recent years, in the manufacturing process for manufacturing a lithographic printing plate support from an aluminum strip, the adhesion between the photosensitive layer in the image area formed on the lithographic printing plate and the surface of the aluminum strip has been improved. Or to improve the water retention in the non-image area,
In many cases, electrolytic surface roughening treatment is performed on an aluminum strip using an electrolytic solution mainly containing hydrochloric acid or nitric acid. This electrolytic surface roughening treatment may be performed by superimposing on the surface of the aluminum band obtained by the above-mentioned mechanical graining treatment such as brush grain, or the surface of the aluminum band may be subjected to a pretreatment such as alkali cleaning. It can also be performed directly after performing.

Here, in the present specification, “mainly” means that the acid or alkali, which is the main component in the acid or alkali solution, is at least 30% by weight, preferably 50% by weight, based on the total acid or alkali component. % By weight.

The electrolytic surface roughening treatment for the aluminum strip is performed by etching in an electrolytic solution mainly composed of hydrochloric acid or nitric acid using an alternating current as an electrolytic current. The frequency range of the AC electrolysis current is 0.1 to 1
The frequency is preferably set to 00 Hz, and more preferably to 10 to 60 Hz. Regardless of whether the electrolyte is mainly composed of hydrochloric acid or nitric acid, the concentration of the solution is preferably 3 to 150 g / l, more preferably 5 to 50 g / l.

The amount of aluminum dissolved in the electrolytic cell is preferably 50 g / liter or less,
g / liter is more preferable. If necessary, various additives may be added to the electrolyte. However, when such an additive is mass-produced, it is difficult to control the concentration of the electrolyte in the aluminum strip. There is a need.

[0052] The current density is preferably a 5~100A / dm ^2, and more preferably, 10~80A / dm ^2. Further, the waveform of the electrolytic current is appropriately selected depending on the required quality, the components of the aluminum strip used, and the like, and is disclosed in JP-B-56-19280 and JP-B-55-19191. It is preferable to use a special AC waveform. The waveform of the electrolytic current and the condition of the electrolytic solution are appropriately selected according to the required quality, the components of the aluminum strip used, and the like, together with the amount of electricity supplied per unit area of the aluminum strip.

<3. Desmut treatment step> Smut and intermetallic compounds are present on the surface of the aluminum strip which has been electrolytically roughened as described above. Here, in order to remove only the smut, at least an alkali treatment using an alkaline solution (alkali treatment step) is performed, and then a two-stage desmut treatment (desmut treatment step) using a low-temperature acidic solution is performed.

First, as an alkali treatment, the aluminum strip is treated with an alkali solution to dissolve the smut. As the alkaline solution, there are various ones such as caustic soda, and it is preferable to treat the aluminum strip with an alkaline solution having a pH of 10 or more and a liquid temperature of 25 to 80 ° C. At this time, the temperature of the alkaline solution is more preferably set to 60 to 80 ° C. from the viewpoint of improving productivity. Liquid temperature 6
By setting the temperature to 0 to 80 ° C., the alkali treatment of the aluminum strip can be completed in a very short time of 1 to 10 seconds. As the alkali treatment with the alkali solution, a dipping method, a shower method, a method of applying an alkali solution to an aluminum strip, or the like can be employed.

Next, the aluminum strip is acid-treated with an acidic solution (acid treatment step). As the acidic solution, a solution mainly containing sulfuric acid is preferable. As the processing equipment, it is preferable to use the equipment described in Japanese Patent Application No. 2000-123805. Solution concentration (acid concentration) is 100 ~
Preferably it is 200 g / l. Acid concentration of 10
If it is less than 0 g / liter, the effect of removing smut will be small. On the other hand, if it is higher than 200 g / liter, the intermetallic compound starts to be removed, so that the adhesion between the photosensitive layer and the aluminum alloy plate is undesirably reduced. A more preferred acid concentration is from 120 to 190 g / liter.

The temperature of the acidic solution is preferably 20 to 50 ° C. If the temperature is lower than 20 ° C., a cooling device for controlling the temperature is required, which is not preferable in terms of equipment cost. 50 ℃
If it is higher, removal of the intermetallic compound is promoted, so that the adhesion between the photosensitive layer and the aluminum alloy plate is reduced, which is not preferable. The acid treatment with an acidic solution can be generally performed by a dipping method, a shower method, a method of applying the solution to an aluminum strip, or the like. By the above desmut treatment,
While removing the smut, the abundance of the intermetallic compound having a diameter (particle size) of 0.1 μm or more on the lithographic printing plate support was increased by 50%.
It can be 00 to 35000 pieces / mm ² .

<4. Anodizing Step> Anodizing is performed on the aluminum strip subjected to desmutting with the alkali solution and the acidic solution as described above (anodizing step). As a result, an anodic oxide film is formed on the surface layer. The amount of anodic oxide film formed is 0.1 to 1
Preferably ^{0g / m 2, 0.3~5g / m} 2 is more preferable. Further, other conditions of the anodizing treatment cannot be unconditionally set because it is necessary to change the setting depending on the electrolytic solution (sulfuric acid, phosphoric acid, oxalic acid, chromic acid, etc.). The concentration (acid concentration) of the solution is 1 to 80 wt%, the temperature of the solution is 5 to 70 ° C., the current density is 0.5 to 60 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 1 second to 5 minutes. Is preferred.

The aluminum strip having undergone the above-described processing steps is wound into a coil to produce a lithographic printing plate support. According to the method for producing a lithographic printing plate support as described above, prior to the anodizing treatment, by performing a predetermined alkali treatment and an acid treatment sequentially as a desmut treatment, a harmful smut on the surface of the aluminum strip is removed. Since it can be removed, a certain amount of intermetallic compound remains, and the surface of the aluminum strip can be appropriately roughened, the subsequent anodic oxidation treatment suppresses the generation of defects due to smut in the anodic oxide film, When a lithographic printing plate support is further provided with a photosensitive layer, the adhesion between the photosensitive layer and the lithographic printing plate support can be improved.

Since the anodic oxide film formed on the aluminum strip is stable and has sufficiently high hydrophilicity, a photosensitive material is immediately applied to the surface of the anodic oxide film to form a photosensitive layer. It can be formed, and can be subjected to a surface treatment as needed. The surface treatment includes, for example, providing a silicate layer of an alkali metal silicate or an undercoat layer of a hydrophilic polymer compound on the surface of the aluminum strip. At this time, the coating amount of the undercoat layer is 1 to 150 m
g / m ² is preferred.

In this way, a lithographic printing plate precursor is produced by providing a photosensitive layer on the surface of a lithographic printing plate support provided with an undercoat layer if necessary. Further, the mat layer can be applied after the application and drying of the photosensitive layer. The lithographic printing plate precursor thus obtained is made into a lithographic printing plate through processes such as image exposure and development, and is set in a printing machine.

According to the above manufacturing method, a lithographic printing plate support can be manufactured from a low-purity aluminum raw material such as an aluminum scrap material without strictly controlling the alloy composition of the aluminum raw material as a raw material and the manufacturing process. can do. From such a lithographic printing plate support, a lithographic printing plate precursor, and if a lithographic printing plate is manufactured and used, the adhesion between the photosensitive layer and the aluminum alloy plate during printing is excellent, and the printing durability is improved. be able to.

<< 2. Lithographic printing plate support >> The lithographic printing plate support of the present invention is preferably produced by the above-described production method, and a part of the roughened surface of the lithographic printing plate support is used. a diameter (particle size) 0.1 [mu] m or more intermetallic compounds, preferably present from 5,000 to 35,000 pieces / mm ^2. Since the intermetallic compound plays a role of a spike between the lithographic printing plate support and the photosensitive layer, the adhesion between the two is improved, and excellent printing durability is exhibited.

The existence rate of the intermetallic compound is 5000 / m
If it is less than m ² , the above-mentioned effects cannot be sufficiently obtained, and 3
If the number is greater than 5000 / mm ² , defects in the anodic oxide film are likely to occur, which is not preferable. The more preferable abundance of the intermetallic compound is 10,000 to 30,000 / m
m ² . The diameter (particle size) of the intermetallic compound is 0.1.
1 μm or more is preferable, but 0.2 to 2.0 μm is more preferable. If the diameter (particle size) of the intermetallic compound is less than 0.1 μm, the adhesion to the photosensitive layer provided on the surface of the lithographic printing plate support may be poor.

The diameter (particle size) and abundance of the intermetallic compound can be adjusted by appropriately changing the conditions for producing the lithographic printing plate support. For example, the treatment temperature in the acid treatment step of the desmut treatment step, the acid concentration of sulfuric acid, and the like may be reduced to reduce the ability to remove the intermetallic compound by the acid, or may be appropriately changed within a predetermined range.

The existence ratio of the intermetallic compound was determined by SEM.
(Scanning electron microscope) or the like, and observe the roughened surface. For example, at 5 places (n = 5), 60 μm ×
In the range of 50 μm, the number of intermetallic compounds was counted and 1 mm
It can be easily calculated by converting to ² .

[0066]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

(Examples 1 to 5 and Comparative Examples 1 to 4)
An aluminum alloy plate serving as a raw material of a lithographic printing plate support of Examples 1 to 5 and Comparative Examples 1 to 4 was prepared from a molten aluminum alloy having the alloy components shown in Table 1 below. As a method for manufacturing an aluminum alloy plate, first, a molten aluminum alloy adjusted to have the composition shown in Table 1 is subjected to a molten metal treatment including degassing and filtration, and is subjected to a DC casting method to a thickness of 5 mm.
A 00 mm ingot was produced. After the ingot surface was shaved by 10 mm, the ingot was heated to 400 ° C. without performing the soaking treatment.
After hot rolling to a thickness of 4 mm in the above, the thickness was reduced to 1.5 mm by cold rolling, intermediate annealing was performed, finished to 0.24 mm again by cold rolling, and the flatness was corrected. 1 to
An aluminum alloy plate as a raw material of the lithographic printing plate support of No. 5 and Comparative Examples 1 to 4 was produced.

[0068]

[Table 1]

Here, the aluminum alloy plates in Examples 1 to 5 have an aluminum purity within a predetermined range and within a range specified in the present invention. On the other hand, the aluminum alloy plate in Comparative Example 1 has an aluminum purity outside the range specified in the present invention. The aluminum alloy plate in Comparative Example 2 was prepared by dissolving a new aluminum ingot having a purity of 99.7% or more and adding a mother alloy so as to have a predetermined component, thereby obtaining a general composition as a lithographic printing plate of JIS1050. And is out of the range specified in the present invention. The aluminum alloy plate in Comparative Example 3 used a lithographic printing plate support used for 70% of the raw materials.
This is a reproduction of Example 3 described in Japanese Patent No. 5534, and the aluminum purity is out of the range specified in the present invention. The aluminum alloy plate in Comparative Example 4 was the same as Comparative Example 3
This is a material having substantially the same aluminum purity as that of, but having relatively high Mn.

With respect to the aluminum alloy sheets in Examples 1 to 5 and Comparative Examples 1 to 4, the raw material costs were compared, and the rollability in producing the aluminum alloy sheets was evaluated.
Table 2 shows the results. The comparison of the raw material costs and the evaluation of the rollability were performed as follows.

(1) Comparison of raw material costs:
It mainly consists of the cost of the aluminum ingot and the processing cost for processing the aluminum ingot into a plate. Since the processing cost is the same if the manufacturing method is the same, the cost of the aluminum ingot was compared here.
The cost of the aluminum ingot was calculated by calculating the cost (amount per g) equivalent to the aluminum ingot, and subtracting the cost (cost equivalent to the aluminum ingot) required to produce the aluminum alloy plate of Comparative Example 2 by 100. Examples 1 to
The cost required to produce the aluminum alloy plates of Comparative Example 5 and Comparative Examples 1 and 3 was evaluated as a relative value.

(2) Evaluation of Rollability Rollability is determined by determining whether rolling can be performed to a predetermined thickness (cold rolled thickness of 0.24 mm) without any problem when manufacturing an aluminum alloy plate. Was evaluated. The evaluation indices are as follows. ：: No problem ○ △: There is slight cracking, but rolling is possible ×: Cracking occurs and rolling is impossible

[0073]

[Table 2]

Comparative Example 3 is a reproduction of Example 3 described in JP-A-7-205534, in which the used lithographic printing plate was used for 70% of the raw material, and the raw material cost was 5%. Although a down effect was obtained, Examples 1 to 5
Was 35 to 65%, which was an even greater cost reduction effect than Comparative Example 3. Further, the used lithographic printing plate used in Comparative Example 3 has a problem that it cannot be obtained stably.

In Comparative Example 1, although the cost reduction effect was great, since the aluminum purity was outside the range specified in the present invention, cracks occurred during rolling, and an aluminum alloy plate could not be produced stably. Comparative Example 4 is an aluminum alloy plate containing relatively large amounts of Mn and containing only 0.03 wt% of Cu, which is less than the preferred range of the present invention.

The aluminum alloy sheets of Examples 1 to 5 and Comparative Examples 2 to 4 which could finally produce aluminum alloy sheets were subjected to a surface roughening treatment as follows.

First, the aluminum alloy plates of Examples 1 to 5 and Comparative Examples 2 to 4 were subjected to a surface roughening treatment by brush grains using a pmistone suspension (No. 8 brushes × 3). Roughening treatment step). After washing with water, 75
At 25 ° C., alkali etching was performed with a 25% NaOH solution to 6 g / m ² (alkali etching treatment step).
After washing with water, a desmut treatment was performed at 40 ° C. with 9 g / liter of nitric acid, and then an electrolytic surface roughening treatment was performed (electrolytic surface roughening treatment step). The electrolytic surface-roughening treatment is performed by using 9 g / liter of nitric acid as an electrolytic solution and increasing the amount of electricity at 50 ° C. to 180 C / dm ^2.
Went as.

After washing with water, alkali treatment (alkali treatment step) using a 25 wt% NaOH solution was performed as a desmut treatment by a shower method. NaO used
The H solution had a pH of 13 and a liquid temperature of 75 ° C. Also,
The alkali treatment time is 4 seconds, and the etching amount is 1 g / m
^{And 2} . After the alkali treatment, the substrate was washed with water, and subjected to an acid treatment (acid treatment step) with sulfuric acid at a liquid temperature of 30 ° C. and an acid concentration of 170 g / liter by a shower method (above, a desmut treatment step). The acid treatment time was 4 seconds.

After the electrolytic surface roughening treatment and the desmutting treatment,
The appearance was evaluated by visual evaluation. Table 2 shows the results.
The evaluation indices are as follows. ○: No unevenness ○ △: Slight roughness unevenness △: Smoothness unevenness

Further, an intermetallic compound present on the surface was observed using an SEM (scanning electron microscope: T220A manufactured by JEOL Ltd.). For observation, SEM photographs at a magnification of 3000 were photographed in five visual fields (60 μm × 50 μm), and the abundance ratio of the intermetallic compound per unit area (mm ² ) was calculated based on the intermetallic compound particles in each visual field. Table 2 shows the results.

After the desmutting treatment, anodizing treatment (direct current electrolysis in a sulfuric acid solution at 30 ° C. and an acid concentration of 170 g / liter) was performed (the average current density was 15 A / dm ^2, and the amount of the formed anodic oxide film was 2.5 g. / M ² ), wash with water,
A lithographic printing plate support was prepared.

One side of the prepared lithographic printing plate support was subjected to an undercoating treatment by a conventional method, and then a photosensitive solution having the following composition was applied so that the applied weight after drying was 2.5 g / m ^2. Then, a photosensitive layer was provided to prepare a photosensitive lithographic printing plate precursor.

Photosensitive solution composition: ester compound of naphthoquinone-1,2-diazide-5-sulfonyl chloride with pyrogallol, acetone resin (US Pat. No. 3,635,709, described in Example 1 in Example 1)・ 0.75g, Cresol novolak resin ・ ・ ・ 2.00g, Oil Blue # 603 (manufactured by Orient Chemical) ・ ・ ・ 0.04g, Ethylene dichloride ・ ・ ・ 16g, 2-methoxyethyl acetate ・ ・ ・ 12g

Further, in order to examine whether or not abnormal coarse grains were formed in the electrolytic surface roughening, the surface of the support before coating the photosensitive layer was scanned with a scanning electron microscope (T-Electronics Co., Ltd.).
Observation was performed at a magnification of 1000 times and 2000 times using 20). Table 2 shows the results. The evaluation indices are as follows. ：: No abnormal coarse grain was generated. Δ: Not abnormal coarse grain, but slightly large coarse was generated. X: Abnormal coarse coarse was generated.

Each lithographic printing plate precursor was subjected to image exposure and development by a conventional method to prepare a lithographic printing plate, which was mounted on a printing machine, and the printing durability was evaluated. The printing durability was evaluated with relative values for each of the examples and comparative examples, with the value of comparative example 2 being 100.

As shown in Table 2, in Examples 1 to 5, the printing durability after the surface roughening treatment and the anodic oxidation treatment was improved compared to Comparative Example 2 of the conventional general JIS 1050 material composition. I was This is presumably because in Examples 1 to 5, the intermetallic compound in the surface layer was larger than that in Comparative Examples 2 to 4, so that the adhesion to the photosensitive layer was improved and excellent printing durability was exhibited.
In particular, in Comparative Example 4, it is considered that the adhesion to the photosensitive layer was reduced due to the occurrence of abnormal coarse grain.

In the above embodiments, the DC casting method was described as the aluminum casting method. However, the present invention is not limited to the casting method, and is represented by, for example, a twin-roll type or a twin-belt type. A continuous casting method can also be used. In this case, the running cost can be further reduced as compared with the DC casting method, so that a greater cost reduction effect can be obtained.

[0088]

The lithographic printing plate support of the present invention has excellent adhesion to the photosensitive layer and excellent printing durability, does not require the provision of an expensive intermediate layer in the production stage, and has a uniform roughness. Since it is manufactured using extremely inexpensive raw materials without the need for surface treatment, the cost can be reduced.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA12 AA14 AB03 2H096 AA06 CA03 2H114 AA04 AA14 AA23 DA04 DA73 EA01 EA03 GA03 GA05 GA06 GA08 GA09

Claims (5)

[Claims] 1. An aluminum content of 95 to 99.4 w
A lithographic printing plate support, characterized in that at least a roughening treatment and an anodic oxidation treatment are applied to an aluminum alloy plate having a content of t%. 2. At least Si and Mn in total
The lithographic printing plate support according to claim 1, wherein the support is contained in an amount of 0.5 wt% or more. 3. A part of the roughened surface has a diameter of 0.1
5000 to 35000 intermetallic compounds having a particle size of at least
The support for a lithographic printing plate according to claim 1 or 2, wherein mm ^{2 is} present. 4. The lithographic printing plate support according to claim 1, wherein the support contains 0.05 wt% or more of Cu. 5. The lithographic printing plate support according to claim 1, wherein a raw material of the aluminum alloy plate contains at least one of a recycled aluminum metal and a scrap material in an amount of 1 wt%. .