JP2003165279A - Aluminum alloy material for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve thermosoftening observed at an aluminum alloy material of a lithographic printing plate at the time of printing without impairing electrolytic etching properties. <P>SOLUTION: The aluminum alloy material for the lithographic printing plate contains 0.1 to 0.6% of Fe, 0.01 to 0.2% of Si, 0.003 to 0.2% of Sc, further, as desired, 0.003 to 0.1% of total sum of one or more types of Zr, Y and Hf and the balance of Al and unavoidable impurities. Thus, the thermosoftening resistance can be improved without impairing the electrolytic etching properties by generating a fine AlSc intermetallic compound, and the printing plate having excellent printing quality and printability can be provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum alloy material for a lithographic printing plate, which is used as a PS plate which has a photosensitive layer formed in advance and is subjected to development processing and then used as it is or after the photosensitive layer is baked. Is.

[0002]

2. Description of the Related Art In lithographic printing, a photosensitive layer is formed in advance,
A PS plate which is used as it is after development processing or after baking processing of a photosensitive layer is widely used, and the PS plate has a rough surface on which a photosensitizer is applied. As the constituent material of the printing plate, a 1050 series aluminum alloy excellent in electrolytic etching property is widely used.
This PS plate is manufactured using the above aluminum alloy through a predetermined manufacturing process. First, a surface treatment is applied prior to the application of the photosensitizer. In this surface treatment, the surface of the printing plate is roughened by electrolytic etching, and then anodized film is treated. Before the roughening treatment, cleaning such as caustic treatment is performed for the purpose of degreasing and the like. .

The above roughening treatment is carried out so that the photosensitive agent is closely adhered and fixed to the printing plate in the formation of the photosensitive layer, and this adhesiveness affects the performance as the printing plate. That is, if there is an unetched portion on the roughened surface, or if the distribution of pits formed by roughening is uneven, the performance of the printing plate will be adversely affected, so it is necessary to obtain a good roughened state. become. Further, after the surface roughening treatment, a photosensitive agent is applied and a developing treatment is performed. After the development process, a baking process (also called burning) is performed by heating at about 200 to tens of degrees Celsius. By this baking process, the photosensitive film left unmelted by the development is cured, and the abrasion resistance and adhesion in printing are improved, and the printing durability is improved.

[0004]

However, the aluminum alloy material is easily softened by heat in the above-mentioned baking treatment, and in extreme cases, plate breakage may occur. For this reason, conventionally, there is a demand for a material that is less likely to be thermally softened while being expected to have improved printing durability. Zr as one of them
An alloy material to which is added is proposed (Japanese Patent Laid-Open No. 59-1).
53861). According to the research conducted by the present inventor, Z
A baking treatment (for example, 260 ° C. to 290 ° C.) is performed by adding r.
It has been found that it is necessary to add a relatively large amount of Zr exceeding 0.1% in order to obtain sufficient heat-resistant softening resistance for 10 minutes at 0 ° C. However, when the amount of Zr added exceeds 0.1%, a coarse intermetallic compound is formed during casting, or coarse pits are formed on the electrolytically-etched surface due to changes such as a layered structure.
Alternatively, it has been found that the layered structure may cause streak defects, which adversely affects the roughening treatment. Therefore, it is difficult to improve the heat softening resistance by adding Zr without impairing the electrolytic etching property. Therefore, the present inventor has earnestly studied the alloy components capable of improving the thermal softening property without impairing the electrolytic etching property in the surface roughening treatment, and completed the present invention.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an aluminum alloy material for a lithographic printing plate which is excellent in heat softening resistance and electrolytic etching property.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 of the aluminum alloy material for a lithographic printing plate according to the present invention has a mass% of Fe: 0.1 to 0.6%,
Si: 0.01 to 0.2%, Sc: 0.003 to 0.2
%, With the balance being Al and inevitable impurities.

The invention of an aluminum alloy material for a lithographic printing plate according to claim 2 is the same as the invention according to claim 1, further comprising:
0.003 in total mass% of one or more of Zr, Y and Hf
It is characterized by containing ~ 0.1%.

The invention of an aluminum alloy material for a lithographic printing plate according to claim 3 is the same as the invention according to claim 1 or 2, wherein an AlSc-based intermetallic compound or AlSc-based compound having an equivalent circle diameter of 20 Å or more, and AlZr. System, AlY system and Al
500 or more Hf-based intermetallic compounds in a plane
It is characterized in that they are dispersed by m ² or more.

The reasons for limiting the components and the like specified in the present invention will be described below. In addition, all component contents are shown by mass%.

Fe: 0.1 to 0.6% Fe forms an AlFe-based intermetallic compound and increases the strength of the material. It also serves as a starting point for electrolytic etching. However, if it is less than 0.1%, these effects cannot be obtained. On the other hand, if the content exceeds 0.6%, coarse crystal precipitates are formed during casting to coarsen pits in electrolytic etching. Therefore, the Fe content is set within the above range. For the same reason, it is desirable to set the lower limit to 0.2% and the upper limit to 0.4%.

Si: 0.01 to 0.2% Si forms an AlFeSi-based intermetallic compound, which makes recrystallized grains fine during hot rolling and increases strength. 0.01
If it is less than%, this effect is insufficient and the crystal grains become coarse. Further, it is necessary to use high-purity metal, which results in high cost. On the other hand, if the content exceeds 0.2%, coarse Si precipitates cause coarse pits in electrolytic etching. Therefore, the Si content is set within the above range. For the same reason, it is desirable to set the lower limit to 0.04% and the upper limit to 0.10%.

Sc: 0.003 to 0.2% Sc crystallizes in the material as an AlSc intermetallic compound
Has the effect of suppressing dislocation opening or recrystallization,
Addition of a small amount improves the heat softening property. Also, finely
The deposited AlSc-based intermetallic compound is
It becomes the starting point of the etching, and the pits are made finer and electrolytic etching is performed.
It also has the effect of improving sex. However, less than 0.003%
Then, the effect of improving the heat softening resistance and the electrolytic etching
The effect of refining the unit is not obtained. On the other hand, 0.2%
If contained in excess, coarse ScAl _ThreeIntermetallic compound of
It is formed and makes the electrolytically etched rough surface non-uniform. this
Therefore, the content of Sc is set within the above range. The same
For this reason, the lower limit is over 0.01% and the upper limit is 0.1%.
Is desirable.

Zr, Y, Hf: 0.003 to 0.1% If one or more of Zr, Y and Hf is further added to the above Sc, more excellent thermal softening property and electrolytic etching property can be obtained. . However, if the total amount is less than 0.003%, the effect of improving the heat softening resistance and the electrolytic etching property cannot be sufficiently obtained. On the other hand, if the total content exceeds 0.1%, a coarse intermetallic compound is formed, and the electrolytically etched rough surface is made non-uniform. For these reasons, the total amount of these components is set within the above range. For the same reason, it is desirable to set the lower limit of the total amount to more than 0.01% and the upper limit to 0.05%.

Intermetallic compound: equivalent circle diameter of 20 Å or more, dispersion number of 500 / mm ² or more AlSc-based, AlZr-based, AlY-based and AlHf-based intermetallic compounds serve as a starting point of electrolytic etching to improve electrolytic etching property. Can be made. However, an intermetallic compound having an equivalent circle diameter of less than 20Å is unlikely to be a starting point of electrolytic etching. Further, in order to effectively improve the electrolytic etching property, it is necessary to disperse a considerable number of intermetallic compounds having a circle equivalent diameter of 20 Å or more, and 500 / in a plane.
If it is less than mm ² , the effect of improving the heat softening resistance and the electrolytic etching property cannot be sufficiently obtained. Further, it is desirable that the intermetallic compound has a circle equivalent diameter of 5 μm or less because coarse particles exceeding 5 μm coarsen the electrolytic etching pits.

(Avoidable Impurities) In addition to the above-mentioned additional components, the alloy of the present invention may contain inevitable impurities. The unavoidable impurities include Cr, Ga, Pb, V,
Ni and the like can be given.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum alloy material of the present invention is
It can also be produced by combining conventional methods or known production methods.

The manufacturing process for obtaining the alloy material of the present invention will be described below. First, the aluminum alloy which is the material of the present invention can be melted by a conventional method, and can be obtained by, for example, adjusting the components so that they fall within the above-mentioned range and casting. After that, the conventional method is 550
Homogenization treatment is performed above ℃ to homogenize the components. However, in the step of obtaining the alloy sheet of the present invention, if the temperature of the homogenization treatment exceeds 550 ° C., the intermetallic compound particles are likely to coarsen, so 550 ° C. or less, that is, 350 to
It is desirable to carry out a homogenization treatment at 550 ° C. Processing time is 1
More than time is desirable. In terms of the size of the particles of the intermetallic compound, the higher the homogenization temperature is, the shorter the treatment needs to be. It is also possible to omit the homogenization treatment. The aluminum alloy having a predetermined component can be made into an aluminum alloy thin plate through the steps of hot rolling and cold rolling. Note that an annealing step may be appropriately provided in the above step. The aluminum alloy thin plate obtained through the above steps is used as an aluminum alloy material.

As described above, the alloy material is usually surface-cleaned prior to the application of the photosensitizer. In surface cleaning, generally, as described above, cleaning is performed for the purpose of removing oil, dirt, etc. adhering to the surface. This washing is usually done by caustic treatment with caustic soda. However, the present invention may include an acid treatment and other treatments, or may be a treatment not including a caustic treatment, and the point is that the treatment process is intended for cleaning. . The solution used for washing, the procedure of washing, the conditions, etc. are not particularly limited in the present invention, and can be carried out by a conventional method. Further, the surface may be cleaned by mechanical polishing in combination with the above-mentioned cleaning step or without passing through the above-mentioned cleaning step.

The surface-cleaned aluminum alloy material is then subjected to a roughening treatment to roughen the surface. This roughening treatment is performed by electrolytic etching. This roughening is carried out for the purpose of firmly fixing the photosensitive agent described later on the surface of the printing plate. In the present invention,
The conditions of this electrolytic etching are not particularly limited and can be carried out by a conventional method. The material of the present invention is excellent in electrolytic etching property, and by the etching,
A rough surface with few unetched parts and uniform pits can be obtained.

Further, an anodic oxide film is usually formed on the above alloy material after the surface roughening treatment to prevent corrosion and wear.
This film treatment can be performed by a conventional method, and the present invention is not particularly limited in terms of production conditions and film properties. After forming the anodized film, a desired photosensitizer is applied to the surface thereof. The type of the photosensitizer is not limited in the present invention, and known photosensitizers can be used. Further, the apparatus used for coating the photosensitizer, the coating method, and the coating amount are appropriately selected. After applying the photosensitizer, development processing is performed. The development treatment can be performed by a known method, and the content of the invention is not particularly limited. After the development, a baking process is performed at a predetermined heating temperature and heating time. The temperature is usually 200 to 280.
The temperature is 5 to 20 minutes. However, as the present invention,
It is not limited to this condition. In the present invention, there is little heat softening in the above baking treatment, and heat resistance softening property is excellent.

[0021]

EXAMPLE An example of the present invention will be described below. Table 1
An aluminum alloy was melt-cast with the composition shown in 1 and the surface of the obtained slab was chamfered. Then, 350-550 ℃,
Homogenization treatment was performed for 1 hour or more, and an aluminum alloy plate (test material) was obtained through hot rolling and cold rolling.

[Thermal softening property] Each test material was heated at 330 ° C. for 10 minutes.
After heating for a while, the strength was measured by a usual method. Before heat treatment
The difference between the material strength and the material strength after heat treatment is 10 N / mm
^TwoLess than ◎ 10 N / mm^Two20 N / mm above^TwoLess than
○, 20 N / mm^Two30 N / mm above ^TwoLess than △,
30 N / mm^TwoThe above is marked with x, and the results are shown in Table 1.
It was

[Electrolytic Etching Property] Each test material was degreased with a weakly alkaline 2% aqueous surfactant solution at 50 ° C. for 30 seconds, washed with water for 10 seconds, and washed with 10% NaOH at 50 ° C. for 10 seconds. Etching for 10 seconds, washing with water for 10 seconds, desmutting with 10% nitric acid for 10 seconds, 1
It was washed with water for 0 seconds. Then, 2% hydrochloric acid aqueous solution, 25
Electrolytic etching treatment was performed for 30 seconds with a sine wave of 60 ° C., 60 A / dm ² , and 60 seconds, followed by washing with water for 10 seconds. Furthermore, 1 at 50 ℃
Immerse in 0% nitric acid for 15 seconds, wash with water for 10 seconds, 120 ° C
And dried for 15 minutes. The surface of this sample was observed with an electron microscope at a magnification of 500. Area ratio of pits with equivalent circle diameter of more than 10 μm is less than 2% ◎ 2% or more and less than 5% ○ 5%
As described above, less than 10% was evaluated as Δ, and more than 10% was evaluated as x. The results are shown in Table 1 as electrolytic etching properties. The presence of many pits having an equivalent circle diameter of more than 10 μm adversely affects the adhesion and fixing property of the photosensitive agent. Therefore, the smaller the number of such pits, the better the electrolytic etching property.

[Intermetallic compound] 20 points on the surface of each test material
It was observed with a transmission electron microscope at a magnification of 50,000 times, and the
The size and the number were measured. The types of intermetallic compounds are
It was identified by X-ray analysis. Al with a diameter equivalent to 20 Å or more
Between Sc-based or AlZr-based, AlY-based, and AlHf-based metals
500 compounds / mm^TwoIf the above is dispersed, ○,
500 pieces / mm ^TwoWhen the value is less than x, the result is shown in Table 1.
It was shown to.

[0025]

[Table 1]

As shown in Table 1 above, the test materials (Examples) of the present invention show little decrease in strength during heat treatment, are excellent in heat softening resistance, and are also excellent in electrolytic etching property. On the other hand, in Comparative Example, even if the excellent heat softening resistance is inferior to the electrolytic etching property, the heat softening resistance,
None of them have excellent electrolytic etching properties.
That is, it has been clarified for the first time in the present invention that an aluminum alloy material for a lithographic printing plate having excellent heat softening resistance and electrolytic etching property can be obtained.

[0027]

As described above, according to the aluminum alloy material for a lithographic printing plate of the present invention, Fe:
0.1-0.6%, Si: 0.01-0.2%, Sc:
0.003 to 0.2%, and optionally Z
0.003 to 0.1% in total of one or more of r, Y and Hf
Since the balance includes Al and the unavoidable impurities, the heat softening resistance can be improved without impairing the electrolytic etching property, and both the electrolytic etching property and the heat softening property are excellent.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03F 7/09 501 G03F 7/09 501

Claims (3)

[Claims] 1. Fe: 0.1 to 0.6% by mass% and S
i: 0.01 to 0.2%, Sc: 0.003 to 0.2%
An aluminum alloy material for a lithographic printing plate, comprising: and the balance consisting of Al and unavoidable impurities. 2. The aluminum alloy material for a lithographic printing plate according to claim 1, further comprising one or more of Zr, Y and Hf in a total mass% of 0.003 to 0.1%. 3. An in-plane 5 or more AlSc-based intermetallic compound or AlSc-based compound having an equivalent circle diameter of 20 Å or more and at least one AlZr-based, AlY-based or AlHf-based intermetallic compound.
The aluminum alloy material for a lithographic printing plate according to claim 1 or 2, which is dispersed in an amount of 00 pieces / mm ² or more.