JP2865270B2 - Aluminum alloy plate for printing plate and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is an aluminum case for a printing plate
With respect to the metal plate and its manufacturing method, more specifically, as a support plate for a PS plate used for an offset printing plate, there is little etching unevenness during electrolytic surface roughening, and an aluminum alloy plate for a printing plate excellent in stain resistance and The present invention relates to the manufacturing method.

[0002]

2. Description of the Related Art In offset printing, it has been known that aluminum is generally used as a support in the past. Therefore, it is necessary to roughen the surface.

[0003] Conventionally, as this surface roughening method,
There have been processing methods such as ball polishing and brushing polishing, but recently, the surface of the plate has been electrochemically treated using hydrochloric acid or an electrolytic solution mainly composed of hydrochloric acid or nitric acid or an electrolytic solution mainly composed of this. The main method is an electrolytic surface-roughening treatment method for roughening or a treatment method combining the above-mentioned mechanical treatment method and the electrolytic surface-roughening treatment method.

As an aluminum material suitable for such an electrochemical surface roughening treatment, an aluminum alloy having a composition of Fe: 0.35 to 1% and Si: 0.2% or less is subjected to a homogenization treatment and then hot-rolled. , 40-80
% Cold-rolled aluminum alloy sheet (Japanese Patent Application Laid-Open
-28874), Fe: 0.1 to 1.0%, Si: 0.02 to 0.15%, C
u: an aluminum alloy plate having a composition of 0.003% or less (Japanese Patent Application Laid-Open No. 58-221254), and others disclosed in Japanese Patent Application Laid-Open Nos. 58-42493 and 59-67349.
And the like, and a printing plate material suitable for electrolytic surface roughening by adding a predetermined amount of Fe, Si or Cu has been proposed.

On the other hand, regarding the electrochemical surface roughening treatment, uniformity of electrolytic etching is required to have excellent printing performance such as stain resistance of a non-image portion, and the commercial value of a PS plate. Due to this problem, the macro organization must be fine and so on.

As an aluminum material suitable for such a demand, Japanese Patent Publication No. 5-28197 and Japanese Patent Publication No. 5-2819
8, JP-A-3-122241, JP-A-3-1775
No. 28, Japanese Patent Application Laid-Open No. 3-177529, etc., are proposed to contain a predetermined amount of Fe, Si, Ti, Ga, Ni, etc., and to control the Si content ratio in the intermetallic compound and the amount of precipitated Si. By preventing specific intermetallic compounds from making the electrolytic etching pit non-uniform, or by appropriately performing hot rolling or ingot refining, coarse (100 μm or more) recrystallized grains are generated. It has been proposed to prevent this.

Further, conventionally, as a method of manufacturing an aluminum alloy plate for a printing plate, a method of performing anodization on the surface after roughening the aluminum alloy plate has been performed (Japanese Patent Publication No. 57-16918). Anodization is performed to improve printing durability, and it is described in Japanese Patent Publication No. 57-16918 that increasing the hardness of anodic oxidation improves printing durability.

Further, regarding the stain resistance, Japanese Patent Laid-Open No.
No. 34594, maximum length of 1μ existing in anodic oxide film
It is disclosed that controlling the number of intermetallic compounds of m or more to 7000 / mm ² or less has an effect on stain resistance. Also,
Japanese Examined Patent Publication No. 5-28197 describes a simple substance S in an aluminum plate.
It is described that i affects the properties of the anodized film.

[0009] However, as the quality of printed matter such as color printing has become higher, the required level of printing stains in the non-image area has also been improved, and the electrolytic surface roughening obtained by the above-mentioned prior art has been mainly achieved by making the electrolytic etching pits uniform. Surface control is no longer sufficient. That is, when the printing machine is temporarily stopped (about one hour) and the printing is performed again in the printing stain of the non-image portion, the printing stain occurs in the non-image portion. This printing stain does not correspond to the uniformity of the electrolytic etching pits, but is considered to be caused by an anodic oxide film. Therefore, an aluminum plate for a printing plate suitable for anodizing treatment has been required.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an anodic oxide film formed on a roughened surface without making the electrolytic etching pits uneven during the electrolytic surface roughening treatment. It is an object of the present invention to provide an aluminum alloy plate for a printing plate which can be improved and provides excellent stain resistance.

As a means for solving the above-mentioned problems, the present invention provides a method for producing a steel sheet comprising Fe: 0.3 to 0.60% and Si: 0.03 to 0.03%.
0.08%, Cu: 0.004 to 0.04%,
And the relation between Fe and Si is 4 ≦ Fe (%) / Si (%)
Is satisfied, and if necessary, Ti: 0.010 to 0.1.
040%, V: 0.03% or less, and the relationship between Ti and V is 1
≦ Ti (%) / V (%) ≦ 40 or B: 1
-20%, the balance being an aluminum alloy consisting of Al and inevitable impurities, and its pitting potential Vc
₁₀ -0.75 (mV) less etching unevenness in electrolytic graining, which is a ≦ Vc _10, and,
The gist is an aluminum alloy plate for a printing plate having excellent stain resistance.

[0012] The method of manufacturing the aluminum alloy ingot containing the above-mentioned chemical components, the homogenization treatment, hot rolling, cold rolling (including intermediate annealing), 430 ~
A homogenization treatment of 560 ° C. × 3 hours or more is performed, and the hot rolling end temperature T (° C.) is set to 320-5 (Fe (%) / Si
(%)) ≦ T (° C.).

[0013]

[Action]

The inventor of the present invention has first made an intensive study on the fact that printing stains in non-image areas, which are referred to as oxidation stains, do not correspond to the uniformity of electrolytic etching pits. As a result, it has been determined that the more porous the formed film, the higher the occurrence rate of the printing stain. And since it is thought that the amount of this printing stain can be reduced as the anodic oxide film formed is denser, the effect of the material on the anodic oxide film quality was also studied diligently. The higher the density, the denser the film is formed. Furthermore, the Fe / Si ratio,
It has been found that the pitting potential can be increased by controlling the manufacturing conditions.

Further, in order to meet the above-mentioned demand, a roughened surface having a uniform and small number of unetched portions (less etching unevenness) can be obtained by electrolytic surface roughening treatment, and the macrostructure becomes finer. In view of the fact that the formed anodized film needs to be an aluminum plate for a printing plate capable of reducing the occurrence of printing stains in the non-image area, the present inventors have made extensive studies. As a result, in order to make the surface of the aluminum alloy plate for a printing plate after electrochemical surface roughening a more microscopically uniform rough surface, in addition to the conventional Fe, Si, and Ti being contained in predetermined amounts, It has been found that the management of the content of Ti, V or B is effective.

[0016] In addition, the appearance of the printing plate may not be improved even if the conventional measures are taken. Regarding the cause, the present researcher has conducted further studies, and as a result, in order to make the macrostructure fine, the T
Although it is effective to refine the ingot by i and B, it was clarified that V originally contained in the base metal and the added Ti-B hindered the refinement effect by Ti-B.

Based on the above findings, more detailed experimental research was conducted, and the present invention has been completed. First, the reasons for limiting the chemical components in the present invention will be described.

Fe: 0.30 to 0.60% Fe has the effect of making the electrolytic surface roughening uniform. Fe is an element that combines with other elements in the aluminum alloy to form an Al-Fe eutectic compound. The Al-Fe eutectic compound has an effect on refining recrystallized grains and has a uniform effect. This has the effect of forming a rough electrolytic surface. However, the content is 0.2
If it is less than 0%, the number of Al-Fe eutectic compounds is small, and the unetched portion is large on the electrolytically roughened surface and the surface is insufficiently roughened. on the other hand,
If it is 0.20% or more and less than 0.30%, the effect of refining the recrystallized grains is small, and the streaks at the time of macro etching become long. On the other hand, if the content exceeds 0.60%, the roughened electrolytic surface becomes non-uniform due to the formation of coarse compounds. Therefore, the Fe content is set to 0.30 to 0.60%.

Si: 0.03-0.08% Si forms an Al-Fe-Si based intermetallic compound and acts as a nucleus for recrystallization between hot passes. However, if it is less than 0.030%, the effect is small, and the streaks at the time of macro etching become long. Also,
If the content exceeds 0.080%, the roughened electrolytic surface becomes non-uniform due to the formation of a coarse compound. Therefore, the Si content is set to be 0.03 to 0.08%.

Cu: 0.004% to 0.04% By controlling Cu appropriately, a uniform electrolytically roughened surface can be formed. However, 0.0
If it exceeds 4%, the pits become coarse and the roughened electrolytic surface becomes uneven. On the other hand, if the content is less than 0.004%, the entire surface is dissolved, the pits become too small, and the surface roughening is insufficient. Therefore, the Cu content is 0.004 to 0.04%.

In addition to the above elements, Ti and V, if necessary,
Alternatively, B can be contained in an appropriate amount.

Ti: 0.010 to 0.040% Conventionally, a mother alloy of Ti-B has been added as a grain refiner, and the addition of Ti-B makes the ingot structure finer and macro-etched. This has the effect of preventing the streaks from becoming longer. However, when Ti exceeds 0.040%, a coarse compound is formed, and coarse pits increase.
The roughened electrolytic surface becomes non-uniform. Conversely, if the content is less than 0.010%, crystal grains cannot be refined, and the streaks due to macro etching become longer. Therefore, the Ti content is 0.010 to 0.04.
0%.

B: 1 to 20 ppm Similarly, the addition of Ti-B has the effect of making the ingot structure finer and preventing the streaks from being lengthened by macro etching. However, when B exceeds 20 ppm, the number of Ti-B particles increases, which generates an unetched portion on the electrolytically roughened surface and increases etching unevenness. Conversely, if it is less than 1 ppm, the crystal grains cannot be refined, and the streaks due to macro etching become longer. Therefore, the B content is set to 1 to 20 ppm.

V: 0.03% or less, 1 ≦ Ti (%) / V (%)
≦ 40 Conventionally, a mother alloy of Ti-B has been added as a grain refiner, and the Al-Ti-B intermetallic compound due to the addition of Ti-B becomes a nucleus, and the cast structure is refined. It has been known. As a result of intensive studies on the mechanism of the miniaturization, the present inventors have found that the V content is involved in the miniaturization.

That is, when V is contained, it is associated with B in the molten metal and exists as a VB compound. As a result, the number of Al-Ti-B intermetallic compounds is reduced, and the fineness of the cast structure is reduced. Is to hinder the transformation. Specifically, when the B content is in the range of 1 ppm to 20 ppm, Ti (%) /
If the ratio of V (%) is less than 1, the cast structure is not refined and the macro structure becomes coarse, while the ratio of Ti (%) / V (%) is 40.
When it exceeds, coarse inclusions due to Ti are formed, coarse pits are formed, and the electrolytically roughened surface becomes non-uniform. Further, even if the V content exceeds 0.03%, a coarse compound is formed, and the electrolytically roughened surface becomes non-uniform. Therefore, the V content is set to 0.0.
At 3% or less, it is necessary to further satisfy 1 ≦ Ti (%) / V (%) ≦ 40.

4 ≦ Fe (%) / Si (%) Conventionally, aluminum alloy plates for printing plates have been made of Al-Fe
It is known that the ratio of Fe (%) / Si (%) is increased to reduce the amount of -Si-based coarse compounds and to make the electrolytically roughened surface uniform. The inventor of the present invention has conducted extensive studies on the material factors affecting the anodic oxide film after the surface roughening. As a result, the formed anodic oxide structure has Al-Fe determined by Fe (%) / Si (%).
It was clarified that the solid solubility of Si in the Si-based intermetallic compound, elemental Si, and Al matrix was involved.

That is, when the Fe / Si ratio is low, the number of Al—Fe—Si based intermetallic compounds and simple substance Si in the Al plate increases, the number of cathodes increases with respect to the aluminum matrix, and the pitting of the Al plate increases. Since the potential is lower than -0.75 mV, Al ions at the interface where the anodic oxide film is formed increase, and the voltage required in the constant current anodic oxidation treatment decreases, so that a porous anodic oxide film is formed. Further, the porous film has a high probability of adsorbing impurities in the fountain solution, so that printing stains in the non-image area are easily generated. Specifically, if the Fe / Si ratio is less than 4, a print stain on a non-image portion which does not correspond to the uniformity of the electrolytic etching pits is generated.

Pitting corrosion potential (Vc ₁₀ ): −0.75 (mV) ≦ Vc ₁₀ It has been known that the cell wall thickness and the number of pores of the anodized film are related to the anodized voltage. The present inventors have intensively studied a result the material factors on the anodic oxide film after roughening was investigated that the pitting potential Vc ₁₀ material influences the voltage in the constant current anodization.

That is, if the pitting potential is low, the voltage for generating Al ions at the interface of the formation of the anodic oxide film in constant current anodic oxidation becomes low, so that a porous anodic oxide film is formed, Printing stains on the image portion are likely to occur. Specifically, the pitting potential Vc ₁₀ is, -0.75 (mV)
If the value is less than 0, the formed film becomes porous and oxidized stain easily occurs. Therefore, the value is set to -0.75 (mV) or more.

Aluminum for planographic printing plate in the present invention
The impurities contained in the aluminum alloy constituting the alloy plate do not impair the object of the present invention as long as they are about the same as those usually contained in commercially available Al ingots.
That is, Mg: 0.020% or less, Cr: 0.020%
% Or less and Zn: 0.020% or less, there is no particular problem.

Next, the manufacturing method of the present invention will be described.
First, the aluminum alloy sheet of the present invention is manufactured by the steps of casting, homogenization, hot rolling, cold rolling, intermediate annealing, and finishing cold rolling. Note that the homogenization treatment and the heating before hot rolling can also be performed. That is, after performing the homogenization treatment, hot rolling can be performed as it is, or hot rolling can be performed after cooling to a predetermined temperature.

However, in the present invention, 430-560 ° C. × 3
It is necessary to perform the homogenization treatment for hr or more. Temperature is 560 ° C
Is exceeded, Al ₆ Fe is transformed into Al ₃ Fe, which is a cathode, and the number of cathodes increases with respect to the aluminum matrix of the material. The pitting potential of the Al plate becomes lower than −0.75 mV. Al ions at the formation interface increase, and the voltage required in the constant current anodic oxidation treatment decreases, so that a porous anodic oxide film is formed, so that printing stains in the non-image area are likely to occur. If the temperature is lower than 430 ° C., homogenization is insufficient, and the roughened electrolytic surface becomes uneven.

It is desirable to start hot rolling at a temperature of 400 to 500 ° C. This is because if the temperature exceeds 500 ° C., the recrystallized grains in the hot rolling pass become coarse with a size of 100 μm or more and the macrostructure becomes coarse, and if the temperature is less than 400 ° C., a coarse compound is formed, and coarse pits increase. This is because the planarized surface becomes non-uniform.

Further, it is necessary to set the end temperature T of the hot rolling in the range of 320-5 (Fe / Si) ≦ T (° C.) with respect to the ratio of Fe to Si. Hot rolling end temperature T is 320-5 (Fe / Si)
If it is less than 1, solid solution Si precipitates as a simple substance Si, the number of cathodes increases with respect to the aluminum matrix of the material, and the pitting potential of the Al plate becomes lower than -0.75 mV. Increases, and the required voltage in the constant current anodic oxidation treatment is reduced, so that a porous anodic oxide film is formed.

The conditions of the intermediate annealing are not particularly limited, but the temperature is increased at a temperature increasing rate of 20 to 150 ° C./hr.
After holding at ~ 500 ° C for 2-5 hours, the temperature decreasing rate is 20-100
At a rate of 5 to 100 ° C./sec in a continuous annealing furnace and a temperature of 12 to 400 to 550 ° C.
After holding for 0 second or less, it is desirable to cool at a temperature lowering rate of 10 to 100 ° C./sec, thereby further shortening the macrostructure.

Next, examples of the present invention will be described.

[0037]

Example 1 No. 1 having the chemical components shown in Table 1 was used. 1 to N
o. The aluminum alloy of No. 18 was melted and cast, homogenized under the conditions shown in Table 1, cold rolled after hot rolling, intermediate annealing (420 ° C. × 0 second), and finished cold at a sheet thickness reduction rate of 80%. Rolling was performed to obtain a plate having a thickness of 0.30 mm.

The surface of the obtained plate (0.98 dm ² ) was degreased with a 5% aqueous sodium hydroxide solution at a temperature of 65 ° C. for 1 minute in accordance with JP-A-1-16651, and then heated in a 10% nitric acid solution at a temperature of 25%.
Neutralized and washed at 0.6 ° C for 1 minute, and with a 0.6 (mol / L) nitric acid electrolyte,
AC electrolysis was performed at a current density of 50 A / dm ² , 50 Hz, 30 ° C., and 30 seconds.

The entire 0.98Dm ² at 350 times using a scanning roughening surfaces of plates was as described above electron microscope (SEM) was subjected to surface observation, and a total from the entire plate of 0.98Dm ² The photograph was taken so that it might be 0.02 mm ² . Based on this photograph, the non-etching rate was determined by the following equation. Unetched rate (%) = (Area of unroughened part)
/ (Whole area) × 100

Based on the above unetched portion ratio, evaluation of the unetched portion was determined based on the following criteria. Unetched part evaluation ○ (good): Unetched rate 0.0 to 0.0
10.0%, Δ (slightly poor): Unetched rate 10.1-2
0.0%, x (bad): Unetched rate of 20.1% or more.

From the above photographs of the observation of the electrolytic surface, a total of 10
A 0 cm line was drawn and the size of the pit below the line was measured. The difference between the size of the smallest pit and the largest pit is 15μ
Those larger than m were evaluated as uniformity evaluation x (defective), and 10 to 15
Those having a thickness of μm were evaluated as uniformity evaluation △ (somewhat poor), and those having a thickness of less than 10 μm were evaluated as uniformity evaluation ○ (good).

Further, the surface of the plate (3 dm ² , rolling direction 15 cm × 10 cm × 2) obtained as described above was subjected to chemical etching (macro etching) with aqua regia to see streaks. When the length of the streaks in the rolling direction is less than 1 cm, the streak is evaluated as ○ (good) and 1-2 cm
Length up to △ (somewhat bad), longer than 2 × (bad)
And

Further, a grained plate (1.5 dm ² , rolling direction 15 cm × 70 c) obtained by the above composition, plate manufacturing conditions and electrolytic surface roughening.
m × 10 sheets) was anodized in 15 wt% sulfuric acid, 35 ° C., 3 A / dm ² , 1 minute, subjected to the post-treatment described in the method 1 of the present invention in JP-A-59-164190, and then subjected to a single-color printing machine. (Komori sprink 26), printing at a speed of 100,000 sheets → stopping for one hour was repeated four times, and the number of print stains in the non-image area was evaluated. As a result, those with no print stains on the non-image portion were evaluated as ○ (good), and less than 10 were evaluated as Δ (somewhat poor),
10 or more were evaluated as x (defective). In addition, in this printing test,
Printing ink (manufactured by DIC: New Champion F Gloss 85)
Ink) was used. The measurement of the pitting potential was performed according to JIS G 0
577.

As shown in Table 2, the test results of the present invention N
O.1 to No.5 are all good in the evaluation of the unetched portion, the evaluation of the streak, the evaluation of the uniformity, and the evaluation of the print stain in the non-image portion.

On the other hand, in Comparative Example No. 6, Fe was 0.30.
%, The evaluation of the unetched portion is poor.
Further, in Comparative Example No7, the uniformity evaluation was poor because Fe exceeded 0.60%. Similarly, Comparative Example No. 8 has a poor uniformity evaluation because Si exceeds 0.08%. Similarly, in Comparative Example No. 11, the evaluation of uniformity was poor because Cu exceeded 0.04%. Comparative Example No. 13 also had poor homogeneity evaluation because the homogenization treatment temperature was lower than 430 ° C. Similarly, in Comparative Example No. 15, the soaking time was insufficient, and the uniformity evaluation was poor.

In Comparative Example No. 10, Cu was 0.004.
%, The pits become too small and the surface is insufficiently roughened. Therefore, it is considered that the surface is not uniform and the uniformity evaluation is poor.

Next, in Comparative Example No. 8, since the Fe / Si ratio was less than 4, the evaluation of print smear in the non-image area was poor.
Similarly, in Comparative Example No. 9, since Si was less than 0.03%, the print stain evaluation of the non-image portion was poor. Comparative Example No. 1
Similarly, in No. 4, since the homogenization temperature is higher than 560 ° C., the evaluation of print smear in the non-image area is poor. Comparative Example No. 16,
17 and 18, the hot rolling end temperature is 320-5.
Since it is lower than (Fe / Si), the print stain evaluation of the non-image portion is poor.

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

Example 2 No. 3 having the chemical components shown in Table 3 1 to N
o. The aluminum alloy of No. 25 was melted and cast, homogenized under the conditions shown in Table 3, and after hot rolling, cold rolling → intermediate annealing (420 ° C. × 0 second) → finish cold at a thickness reduction rate of 80% Rolling was performed to obtain a plate having a thickness of 0.30 mm.

The evaluation of the unetched portion, the streak evaluation, the uniformity evaluation, and the print stain evaluation of the non-image portion of the obtained cold rolled sheet were performed in the same manner as in Example 1.

As shown in Table 4, the results of the test of the present invention N
O.1 to No.5 are all good in the evaluation of the unetched portion, the evaluation of the streak, the evaluation of the uniformity, and the evaluation of the print stain in the non-image portion.

On the other hand, in Comparative Example No. 6, Fe was 0.30.
Muscle evaluation is poor because of less than%. Similarly, Comparative Example No. 9 has poor muscle evaluation because Si is less than 0.03%. In Comparative Example No. 12, similarly, Ti was less than 0.010%, so that the streak evaluation was poor. Similarly, Comparative Example No. 15 also has poor streak evaluation because B is less than 1 ppm.
In Comparative Examples No. 16 and No. 17, similarly, V was higher than the Ti content or V exceeded 0.030%, so that the streak evaluation was poor. In Comparative Example No. 18, the streak evaluation was poor because the hot rolling start temperature exceeded 500 ° C.

In Comparative Example No. 7, the evaluation of uniformity was poor because Fe exceeded 0.6%. Similarly, Comparative Example No. 8 has a poor uniformity evaluation because Si exceeds 0.08%. Similarly, in Comparative Example No. 11, Cu is equal to 0.1.
Since it exceeds 040%, the uniformity evaluation is poor. Similarly, in Comparative Example No. 13, the evaluation of uniformity was poor because Ti exceeded 0.040%. Comparative Example No. 1
Similarly, the homogenization temperature of Sample No. 9 was lower than 430 ° C. and the hot rolling start temperature was lower than 400 ° C., so that the uniformity evaluation was poor. Similarly, in Comparative Example No. 21, the soaking time was insufficient, and the uniformity evaluation was poor.

In Comparative Example No. 10, Cu was 0.004.
%, The pits become too small and the surface is insufficiently roughened. Therefore, it is considered that the surface is not uniform and the uniformity evaluation is poor. In Comparative Example No. 14, since the amount of B exceeded 20 ppm,
The evaluation of the unetched part is poor.

Next, in Comparative Example No. 8, since the Fe / Si ratio was less than 4, the evaluation of print smear in the non-image area was poor.
Similarly, in Comparative Example No. 20, since the homogenization temperature was too high, the evaluation of print smear in the non-image area was poor. Comparative Example No. 2
Similarly, for 2, 23, 24 and 25, the end temperature of hot rolling is 3
Since it is lower than 20-5 (Fe / Si), the print stain evaluation of the non-image portion is poor.

[0057]

[Table 3]

[0058]

[Table 4]

[0059]

As described in detail above, according to the present invention,
The aluminum alloy plate for printing plate obtained by regulating the component composition and homogenizing treatment, regulating the hot rolling conditions has a uniform electrolytic roughened surface, a fine macrostructure, short streaks during macroetching, Microscopically, there is a remarkable effect that etching unevenness is small and printing stains generated in a non-image portion are small.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-254545 (JP, A) JP-A-62-148295 (JP, A) JP-A-60-215728 (JP, A) (58) Investigation Field (Int.Cl. ⁶ , DB name) C22C 21/00-21/18 B41N 1/04 C22F 1/04-1/057

Claims (5)

(57) [Claims] 1. Fe: 0.3% by weight (hereinafter the same)
0.60%, Si: 0.03 to 0.08%, Cu:
0.004 to 0.04%, the relationship between Fe and Si satisfies 4 ≦ Fe (%) / Si (%), and the balance is A
and aluminum alloy consisting of unavoidable impurities.
And its pitting potential Vc ₁₀ is -0.75 (mV) ≤Vc
Less etching unevenness in electrolytic graining, which is a _10, and, printing plate aluminum alloy plate having excellent stain resistance. 2. Ti: 0.010-0.040%,
V: 0.03% or less, the relationship between Ti and V 1 ≦ T
Aluminum alloy satisfying i (%) / V (%) ≦ 40
The aluminum alloy plate for a printing plate according to claim 1, comprising: 3. Al further containing B: 1 to 20 ppm
3. The method according to claim 1, wherein the alloy is made of a minium alloy.
4. The aluminum alloy plate for a printing plate according to item 1 . 4. The aluminum of claim 1, 2 or 3.
Ingot homogenized free alloy, hot rolling, Saishi <br/> to cold rolling, subjected to homogenization treatment above four hundred and thirty to five hundred sixty ° C. × 3 hr, hot rolling finishing temperature T a (℃) 320-5 (Fe
(%) / Si (%)) ≦ T (° C.), an aluminum alloy for a printing plate having little etching unevenness during electrolytic surface roughening and excellent in stain resistance. Plate manufacturing method. 5. The printing plate alloy according to claim 4, wherein the hot rolling is started at a temperature of 400 to 500 ° C.
Manufacturing method of minium alloy plate .