JP2778663B2 - 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 1. Field of the Invention The present invention relates to an aluminum alloy plate for a printing plate used as a support for offset printing or the like, and more particularly to an aluminum alloy plate for a printing plate capable of forming a uniform electrolytically roughened surface. It relates to the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, in offset printing, an aluminum or aluminum alloy (hereinafter referred to as aluminum) plate is generally used as a support. This aluminum plate for a printing plate is obtained by subjecting the surface of an aluminum plate to a surface roughening treatment in order to impart adhesion to a photosensitive film and water retention of a non-image portion. Conventionally, mechanical treatment methods such as a ball polishing method and a brush polishing method have been used as the surface roughening method. Recently, however, an electrolytic solution mainly containing hydrochloric acid or hydrochloric acid or an electrolytic solution mainly containing nitric acid has been used. An electrolytic surface roughening method for electrochemically roughening the surface of an aluminum plate using a liquid, and a processing method combining the above-mentioned mechanical processing method and this electrolytic surface roughening method are mainly used. It is becoming. This is because the rough plate obtained by the electrolytic surface roughening method is suitable for plate making, and also has excellent printing performance,
Further, the electrolytic surface roughening method is suitable for the case where the aluminum alloy plate is coiled and subjected to continuous processing.

As described above, it is required that the surface of the aluminum alloy plate to be roughened be formed with uniform irregularities (pits) by the roughening treatment. In an aluminum alloy plate for a printing plate on which uniform irregularities are formed,
Adhesion with the photosensitive film and water retention are improved, and excellent image clarity and printing durability can be obtained. Also, recently, in order to reduce the cost of the surface roughening treatment, there is a strong demand for the development of a material capable of forming uniform irregularities in a shorter time or with a smaller amount of current.

[0004] An aluminum plate suitable for such an electrochemical surface roughening treatment can be obtained by adding Fe, Cu and other trace elements.
0.2 to 1.0% by weight, Cu: 0.1 to 2.0% by weight, and 0.05 to 0.1% by weight of one or more elements selected from Sn, In, Ga and Zn. Aluminum alloy plates have been proposed (Japanese Patent Laid-Open No. 58-2101).
No. 44). This aluminum alloy plate is characterized by a high dissolution rate with respect to chemical etching.

Further, as an aluminum alloy plate having excellent roughness uniformity, Fe: 0.05 to 0.5% by weight, Mg:
0.1 to 0.9% by weight, Si: 0.2% by weight or less, and Cu: 0.05% by weight or less, and one or more elements selected from the group consisting of Zr, V and Ni. 0.0
An aluminum alloy plate containing 1 to 0.3% by weight and the balance consisting of Al and unavoidable impurities has been proposed (JP-A-62-230946).

Further, as an aluminum alloy plate having good strength and uniformity of pits, Mg: 0.30 to 3% by weight, Fe: 0.15 to 0.50% by weight, Ni: 0.0
05 to 0.30% by weight and Ti: 0.01 to 0.1
0 wt%, Si, Cu, and Mn are each regulated to 0.20 wt% or less, and the balance is Al and the content of each element is 0.10 wt% or less. Has been proposed (JP-A-63-30294).

Further, while forming a uniform rough surface,
As an aluminum alloy plate that prevents contamination of non-image areas and improves tone reproducibility and color tone (brightness) of image areas, F
e: 0.1 to 1.0% by weight, Si: 0.02 to 0.
There has been proposed an aluminum alloy plate containing 15% by weight and an impurity of Cu: 0.003% by weight or less, with the balance being unavoidable impurities other than Al and Cu (Japanese Patent Publication No. 47545/1994).

Furthermore, Fe: 0.1 to 0.5% by weight, Si: 0.03 to 0.30% by weight, Cu: 0.0
01 to 0.03% by weight, Ni: 0.001 to 0.0
3% by weight, Ti: 0.002 to 0.05% by weight and G
a: containing 0.005 to 0.020% by weight, and
An aluminum alloy plate having a total content of a and Ti of 0.010 to 0.050% by weight has been proposed (JP-A-3-177528). In this aluminum alloy plate, streaks (also referred to as streaks, hereinafter referred to as streaks), which are streaky irregularities, and irregular image quality irregularities are improved, and the rough surface is uniform. Dirt on the wire is prevented.

[0009]

However, recently,
In order to reduce the cost, an improvement in the electrolytic processing speed is required, and there is a need for an aluminum plate that can form uniform pits in a short electrolytic surface roughening treatment. That is, even when the electrolytic surface roughening treatment time is short and the pits to be formed are shallow, the etching is uniformly performed in a short time, and an unetched portion (an unetched portion of the aluminum plate surface) occurs on the aluminum plate. It is requested not to.
However, the conventional aluminum plate has not satisfied such a demand.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an aluminum alloy plate for a printing plate in which roughened pits are uniformly formed, and a method for manufacturing the same.

[0011]

The aluminum alloy plate for a printing plate according to the present invention comprises Fe: 0.20 to 0.6% by weight, Si: 0.03 to 0.15% by weight, Ti: 0.0
05 to 0.05% by weight and Ni: 0.005 to 0.
An aluminum alloy plate for a printing plate containing 20% by weight, with the balance being Al and unavoidable impurities, wherein some or all of the elements form an intermetallic compound, and the intermetallic compound contains 0.1% by weight. 5 to 2.0% by weight.

The method for producing an aluminum alloy plate for a printing plate according to the present invention is characterized in that Fe: 0.20 to 0.6% by weight,
i: an aluminum alloy containing 0.03 to 0.15% by weight, Ti: 0.005 to 0.05% by weight, and Ni: 0.005 to 0.20% by weight, with the balance being Al and unavoidable impurities The ingot is subjected to a homogenization treatment at a temperature of 500 to 630 ° C., and then a starting temperature of 400 to 450
A method for producing an aluminum alloy plate for a printing plate, in which hot rolling is performed at a temperature of ° C. to precipitate an intermetallic compound, wherein the aluminum alloy plate contains 0.5 to 2.0% by weight of the intermetallic compound. It is characterized by. In this case,
Further, cold rolling, intermediate annealing, and final cold rolling may be sequentially performed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies to obtain an aluminum alloy plate for a printing plate on which uniform roughened pits are formed. As a result, among the alloy elements contained in the aluminum alloy plate, Fe and Si more added
It has been found that it is effective to add appropriate amounts of Ni and Ti in addition to controlling the content of Ni. Some of these additional elements, in the aluminum matrix,
For example, Al-Fe, Al-Fe-Si and Al-Fe
-Si-Ni intermetallic compounds are formed, and each intermetallic compound functions as a starting point of initial pits during electrolytic surface roughening. As a result, it has been found that a uniform roughened pit is formed. However, when the total amount of the intermetallic compound is excessive, coarse pits are formed, and pit uniformity is impaired. Therefore, it is extremely important to control the content of the intermetallic compound to an appropriate amount.

When manufacturing the above-mentioned aluminum alloy plate for a printing plate, in addition to the above-mentioned chemical components,
It is important to control the homogenization temperature and the hot rolling start temperature to control the amount of precipitation of the intermetallic compound. As a result, when the obtained aluminum alloy plate is subjected to electrolytic surface roughening treatment, the etching is performed uniformly on the electrolytic surface roughened surface, and the pit size does not vary and is uniform. Becomes

First, the reasons for limiting the chemical composition of the aluminum alloy plate for a printing plate according to the present invention will be described.

Fe (iron): 0.2 to 0.6% by weight Fe is a main component of the aluminum alloy, and is an element forming an Al—Fe intermetallic compound in the aluminum alloy. By adding Fe, the recrystallized grains can be made finer, the structure is made uniform, and the mechanical strength is improved. Fe is Al-Fe
A system intermetallic compound is formed and functions as a starting point of initial pits during electrolytic surface roughening. Fe content is 0.
If the content is less than 2% by weight, the initial pits at the time of electrolytic surface roughening become insufficient because the Al-Fe-based intermetallic compound is insufficient. On the other hand, if the Fe content exceeds 0.6% by weight, a coarse compound is formed, and the electrolytically roughened surface becomes non-uniform. Therefore, the Fe content is set to 0.2 to 0.6% by weight.

Si (silicon): 0.03 to 0.15
% By weight of Si forms an Al-Fe-Si-based intermetallic compound to promote formation of initial pits and to improve pit uniformity. If the Si content is less than 0.03% by weight, the formation of initial pits becomes insufficient because of insufficient intermetallic compounds. On the other hand, if the Si content exceeds 0.15% by weight, a coarse compound is formed, and the electrolytically roughened surface becomes non-uniform. Therefore, the Si content is 0.03 to 0.3.
15% by weight.

Ti (titanium): 0.005 to 0.05
% By weight Ti is an element for refining the cast structure. If the Ti content is less than 0.005% by weight, the refining effect becomes insufficient. On the other hand, when the Ti content exceeds 0.05% by weight, T
The micronizing effect due to the i content is saturated, which is wasteful. In addition, a coarse compound is formed, and uneven pits are likely to be generated during the electrolytic surface roughening treatment. Therefore, the Ti content is set to 0.005 to 0.05% by weight.

Ni (nickel): 0.005 to 0.2
0 wt% Ni improves the chemical solubility of the aluminum alloy plate,
It is an element that increases the amount of etching during electrolytic surface roughening.
In addition, Ni is Al-Fe in the aluminum alloy.
-Form a Si-Ni based intermetallic compound. Since this compound has a more noble electrochemical potential than the Al-Fe-Si intermetallic compound, the formation of initial pits during the electrolytic surface roughening is further promoted, and the uniform electrolytic rough surface is formed in a short time. To be formed. Ni content is 0.
If the content is less than 005% by weight, the improvement in chemical solubility is insufficient and the ability to form initial pits is insufficient.
On the other hand, if the Ni content exceeds 0.20% by weight, chemical dissolution is excessively promoted, so that the uniformity of pits on the rough electrolytic surface is impaired. Therefore, the Ni content is
0.005 to 0.2% by weight.

Intermetallic compound: 0.5 to 2.0% by weight The intermetallic compound acts as a starting point of initial pits during electrolytic surface roughening, and plays a large role in improving the uniformity of the rough surface. When the content of the intermetallic compound is small, the formation of the initial pits becomes insufficient, the etching is not sufficiently performed, and an unetched portion is generated. However, if the content of the intermetallic compound is too large, the uniformity of the rough surface may be impaired. For the above reasons, it is extremely important to control the content of the intermetallic compound within an appropriate range.
When the content of the intermetallic compound is less than 0.5% by weight, the ability to form initial pits is insufficient as described above. On the other hand, when the content of the intermetallic compound exceeds 2.0% by weight,
Rough pits are easily formed, and the uniformity of the rough surface is impaired. Therefore, the content of the intermetallic compound is
0.5 to 2.0% by weight.

In the method for producing an aluminum alloy plate for a printing plate according to the present invention, the aluminum alloy ingot having the above-mentioned composition is subjected to a homogenization treatment at a temperature of 500 to 630 ° C. Hot rolling is performed at a temperature to obtain an aluminum alloy plate for a printing plate having an intermetallic compound content of 0.5 to 2.0% by weight. In this case,
After hot rolling, cold rolling, intermediate annealing, and final cold rolling may be sequentially performed. The reasons for limiting the numerical values of the homogenization treatment temperature and the hot rolling start temperature in the method for producing an aluminum alloy plate for a printing plate will be described.

Homogenization temperature: 500 to 630 ° C. When an aluminum alloy is produced from an aluminum alloy ingot by rolling or the like, it is necessary to homogenize at a predetermined temperature before rolling the ingot. By this homogenization treatment, an intermetallic compound is precipitated, and the precipitated compound acts as initial pits, whereby a uniform electrolytic rough surface can be obtained. Homogenization temperature is 500 ℃
If it is less than 1, homogenization is insufficient, and the precipitation amount of the intermetallic compound is too large, so that the uniformity of the electrolytic rough surface is impaired. On the other hand, when the homogenization temperature exceeds 630 ° C,
The precipitation amount of the intermetallic compound becomes too small, the initial pit becomes insufficient, and the unetched portion increases. Therefore,
The homogenization temperature is 500 to 630 ° C.

Hot rolling start temperature: 400 to 450 ° C. After the above homogenization treatment, the aluminum alloy ingot is subjected to hot rolling at a predetermined starting temperature. Hot rolling start temperature is 400
If the temperature is lower than ℃, dynamic recrystallization during rolling is insufficient, and the crystal structure of the rolled sheet becomes non-uniform. In addition, the amount of the intermetallic compound deposited becomes too small, the initial pits become insufficient, and an unetched portion increases during electrolytic surface roughening. On the other hand, when the hot rolling start temperature exceeds 450 ° C., in addition to the crystal grains growing excessively between each pass of the hot rolling, the precipitation amount of the intermetallic compound becomes too large, and the electrolytic roughening occurs. Surface uniformity is impaired. Therefore, the hot rolling start temperature is 4
00 to 450 ° C.

[0024]

EXAMPLES Examples of the present invention will be described below in comparison with comparative examples that depart from the scope of the claims. First,
An example (first example) of the aluminum alloy plate for a printing plate according to the present invention will be described.

First Example An ingot of each aluminum alloy (Examples 1 to 6 and Comparative Examples 1 to 10) having a chemical composition shown in the following Table 1 was face-polished to a thickness of 470 mm and a temperature of 590 ° C. A homogenization treatment at a temperature of 4 hours is performed, then hot rolling is performed with the starting temperature set at 430 ° C., and cold rolling, intermediate annealing and cold rolling are sequentially performed to obtain an aluminum sheet having a thickness of 0.3 mm. An alloy plate was obtained. The chemical components of each aluminum alloy plate were measured using emission spectroscopy. The content of the intermetallic compound was determined by dissolving the aluminum alloy plate with phenol, filtering the solution, and measuring the residue (intermetallic compound) by an absorbance method and an atomic absorption method.

[0026]

[Table 1]

Next, each of the aluminum alloy plates manufactured as described above was subjected to degreasing and neutralization cleaning under the processing conditions 1 or 2 shown in Table 2 below, and then subjected to AC electrolytic surface roughening treatment. Further, a desmut treatment for removing oxides and the like formed by electrolysis was performed. After completion of the desmutting treatment, each aluminum alloy plate was washed with water and dried, cut to a certain size, and used as a test material. In addition, 1 in Table 2
dm ² is 0.01 m ² .

[0028]

[Table 2] The unetched portions and uniformity of each test material were evaluated by the following tests.

Evaluation of Unetched Area The roughened surface of each test material was observed at a magnification of 350 times using a scanning electron microscope (SEM) so that the area of the visual field was 0.02 mm ^2. Photo taken. From the obtained photograph, the unetched rate was calculated by the following mathematical formula 1.

[0030]

## EQU1 ## Unetched rate (%) = area of unroughened part / total area × 100

From this calculation result, the unetched rate is 8.
The case of 0% or less was evaluated as ○ (good), and the case where the unetched rate exceeded 8.0% was evaluated as x (bad), and the unetched portion was evaluated.

Evaluation of uniformity The roughened surface of each test material was observed and photographed by using a scanning electron microscope at a magnification of 500 times. A line having a total length of 100 cm was drawn on the obtained observation photograph, and the size (diameter) of the pit below the line was measured. Those having a difference in size between the smallest pit and the largest pit of 3 μm or less were evaluated as having good uniformity (good) and those having a size larger than 3 μm were evaluated as having poor uniformity (poor).

Table 3 below shows the processing conditions and the evaluation of the unetched portions and the uniformity. In each example and comparative example, each evaluation under processing condition 1 and each evaluation under processing condition 2 were the same.

[0034]

[Table 3]

As shown in Table 3, in Examples 1 to 6, since the content of each element is within the range specified by the present invention, both the evaluation of the unetched portion and the evaluation of the uniformity are good. Met.

On the other hand, in Comparative Example 1, since the Ni content was 0.004% by weight, which was less than the range specified in the present invention, the initial pits and the chemical solubility were insufficient. For this reason, many unetched portions remained, the size of the pits varied, and the uniformity deteriorated. In Comparative Example 2, since the Ni content was 0.300% by weight, which was larger than the range specified in the present invention, the chemical solubility was excessively promoted and the uniformity was poor.

In Comparative Example 3, the Si content was 0.2
Since the content was as large as 0% by weight, a coarse compound was formed, the surface of the electrolytically roughened surface became non-uniform, and both the evaluation of the unetched portion and the evaluation of the uniformity were poor. On the other hand, in Comparative Example 4,
Since the Si content was as low as 0.01% by weight, the intermetallic compound was insufficient, and the formation of initial pits was insufficient. Further, since the Ti content was as small as 0.003% by weight, the refinement of the cast structure was insufficient. For this reason, the uniformity evaluation was poor.

In Comparative Example 5, since the Fe content was as small as 0.15% by weight, initial pits during electrolytic surface roughening were insufficient, and both the evaluation of the unetched portion and the evaluation of the uniformity were poor. .

In Comparative Example 6, since the Fe content was as large as 0.70% by weight, a large number of intermetallic compounds were formed, and the content of the intermetallic compound was increased to 2.33% by weight. For this reason, a coarse compound was formed and the roughened electrolytic surface became non-uniform.

In Comparative Example 7, since the Ti content was as small as 0.003% by weight, the refinement of the crystal grains was insufficient, non-uniform pits were formed, and the uniformity evaluation was poor.
On the other hand, in Comparative Example 8, since the Ti content was as large as 0.06% by weight, a coarse compound was formed, the size of the pits became uneven, and the uniformity evaluation was poor.

In Comparative Example 9, since the content of the intermetallic compound was as large as 2.51% by weight, coarse pits were formed.
Poor uniformity.

In Comparative Example 10, since the content of the intermetallic compound was as small as 0.47% by weight, initial pits were insufficient. For this reason, the unetched portion remains, and the evaluation of the unetched portion becomes poor. In addition, the size of the pits varies, and the uniformity evaluation becomes poor.

Next, an embodiment (second embodiment) of a method for manufacturing an aluminum alloy plate for a printing plate will be described.

Second Example An ingot of each aluminum alloy having the same chemical composition as in Example 1 shown in Table 1 above was beveled to a thickness of 470 mm, and then homogenized under the conditions shown in Table 4 below. , Hot rolling, cold rolling, intermediate annealing and cold rolling to obtain an aluminum alloy plate having a thickness of 0.3 mm (Examples 7 to 9,
Comparative Examples 11 to 14) were obtained. In addition, the chemical composition and the content of the intermetallic compound were measured by the same measuring method as in the first example.

Next, each of the aluminum alloy plates was sequentially subjected to degreasing, neutralization cleaning, immersion, AC electrolytic treatment, surface roughening treatment and desmutting treatment under the treatment conditions shown in Table 2 above. After the obtained aluminum alloy plate was washed with water and dried, it was cut into a certain size to obtain a test material. For each test material, the unetched portion and uniformity were evaluated by the same test method and evaluation criteria as in the first example. The results obtained are shown in Table 4 below.

[0046]

[Table 4]

As shown in Table 4, in Examples 7 to 9, the evaluations for the unetched portions and the uniformity were all good.

On the other hand, in Comparative Example 11, since the homogenization treatment temperature was 488 ° C., which was lower than the temperature specified in the present invention, a large amount of the intermetallic compound was precipitated at 2.08% by weight. For this reason, coarse pits were formed on the rough electrolytic surface, and the uniformity evaluation was poor.

In Comparative Example 12, the homogenization temperature was 640.
C., which is higher than the temperature specified in the present invention, the content of the intermetallic compound was as small as 0.46% by weight. For this reason, initial pits were insufficient, and many unetched portions remained.

In Comparative Example 13, the hot rolling start temperature was 37
Since the temperature was 5 ° C., which was lower than the range specified in the present invention, the precipitation amount of the intermetallic compound was small, and the content was as small as 0.48% by weight. For this reason, the initial pits were insufficient, and the evaluation of the unetched portions was poor.

In Comparative Example 14, the hot rolling start temperature was 47
Since the temperature was 3 ° C., which is higher than the range specified in the present invention, the precipitation amount of the intermetallic compound was as large as 2.03% by weight. For this reason, the uniformity of the rough electrolytic surface was impaired.

[0052]

As described above, the aluminum alloy plate for a printing plate according to the present invention contains a predetermined amount of an intermetallic compound in addition to a predetermined chemical component. And the size of each pit is substantially constant.

In the method for producing an aluminum alloy plate for a printing plate according to the present invention, an aluminum alloy ingot having a predetermined chemical composition is homogenized and hot-rolled under predetermined conditions, so that an appropriate amount of an intermetallic compound is contained. In addition, it is possible to obtain an aluminum alloy plate for a printing plate in which uniform surface roughening pits are formed after the electrolytic surface roughening treatment and the size of each pit is substantially constant.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-177528 (JP, A) JP-A-3-122241 (JP, A) JP-A-62-230946 (JP, A) JP-A-63- 30294 (JP, A) JP-A-3-177529 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C22C 21/00 B41N 1/08 C22F 1/04

Claims (3)

(57) [Claims] 1. Fe: 0.20 to 0.6% by weight, S
i: a printing plate containing 0.03 to 0.15% by weight, Ti: 0.005 to 0.05% by weight, and Ni: 0.005 to 0.20% by weight, with the balance being Al and unavoidable impurities Aluminum plate for printing plate, wherein part or all of the elements form an intermetallic compound, and the intermetallic compound is 0.5 to 2.0% by weight. Alloy plate. 2. Fe: 0.20 to 0.6% by weight, S
i: an aluminum alloy containing 0.03 to 0.15% by weight, Ti: 0.005 to 0.05% by weight, and Ni: 0.005 to 0.20% by weight, with the balance being Al and unavoidable impurities The ingot is subjected to a homogenization treatment at a temperature of 500 to 630 ° C., and then a starting temperature of 400 to 450
A method for producing an aluminum alloy plate for a printing plate, in which hot rolling is performed at a temperature of ° C. to precipitate an intermetallic compound, wherein the aluminum alloy plate contains 0.5 to 2.0% by weight of the intermetallic compound. A method for producing an aluminum alloy plate for a printing plate, comprising: 3. The method for producing an aluminum alloy plate for a printing plate according to claim 2, further comprising sequentially performing cold rolling, intermediate annealing, and final cold rolling.