JP2006312243A - Precoated aluminum alloy plate excellent in radiation properties, scratch resistance and conductivity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-side precoated aluminum alloy plate excellent in press moldability and radiation properties. <P>SOLUTION: The precoated aluminum alloy plate is composed of: a substrate 10 comprising an Al-Mg-Cu type aluminum alloy plate; the lubricating coating film 2 formed on one side of the substrate 10; and the radiant coating film 3 formed on the other surface of the substrate 10. The lubricating coating film 2 is formed by coating one side of the substrate 10 with a first organic resin coating containing inner wax and curing the coating layer on the substrate 10. The radiant coating film 3 is formed by coating the other side of the substrate 10 with a second organic resin coating containing a radiant substance 35, which comprises at least one kind of a substance among titanium oxide, carbon black, silica and zirconium oxide, and by curing the coating layer on the substrate 10. It is preferable to add at least one kind of the radiant substance among titanium oxide, carbon black, silica and zirconium oxide to the lubricating coating film 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a double-sided precoated aluminum alloy plate excellent in press formability and heat dissipation and a press working method thereof. In particular, it is suitable for housings such as personal computers, CD-ROM drives, and PDP (plasma display panel) back panels, inverters and ECU housings for hybrid and electric vehicles, and battery cases. On the other hand, the present invention relates to a double-sided pre-coated aluminum alloy sheet that advantageously prevents the occurrence of coating film cracking and coating film peeling during press working and realizes extremely excellent formability.

As electronic devices have higher functionality and higher performance, the amount of heat generated around the electronic component tends to increase, and countermeasures for releasing heat from the inside of the electronic component housing have become an issue. On the other hand, the use of a heat sink with a fan, which has been conventionally used, is not realistic due to demands for miniaturization and space saving.
Also, due to the downsizing, weight reduction, and complexity of electronic devices, excellent press workability and processing technology are being demanded while using high-strength aluminum alloys.
Therefore, in order to release the heat in the electronic component casing more efficiently, it has been desired to realize high strength and high press formability while providing the material itself constituting the casing with a heat dissipation function.

  For example, when using a coated body in which a heat-dissipating coating film containing no conductive filler is used on the front and back surfaces of the substrate, the temperature in the predetermined heat-dissipation evaluation apparatus is 2.6 ° C. or higher compared to the case where this is not used. One that can be reduced (Patent Document 1), one surface of an aluminum plate provided with an organic resin film containing organic resin fine particles (Patent Document 2), carbon black, titanium oxide, and zinc white are contained in specific amounts, An emissivity of 65% or higher (Patent Document 3), a lubricous coating film formed on one surface, and a conductive coating film formed on the other surface to achieve high moldability and conductivity ( Patent Document 4), by providing an overcoat layer in which resin beads are dispersed on an undercoat layer containing titanium oxide and carbon black, and covering the other surface with a conductive coating film, excellent heat dissipation and scratch resistance Realize conductivity and conductivity And the ones (Patent Document 5), and the like.

  However, as an aluminum alloy plate used for an electronic device casing or the like, its formability and heat dissipation are particularly important, but there is still room for improvement, and it is necessary to further improve its characteristics.

JP 2004-74145 A JP 2002-149083 A Japanese Patent Laid-Open No. 2004-160979 JP 2004-093964 A JP 2003-311791 A

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a double-side pre-coated aluminum alloy plate excellent in press formability and heat dissipation.

According to a first aspect of the present invention, there is provided a substrate made of an Al-Mg-Cu-based aluminum alloy plate, a lubricating coating film formed on one surface of the substrate, and a heat dissipating coating film formed on the other surface of the substrate. Become
The lubricating coating is formed by applying and curing a first organic resin-based paint containing 0.2 to 5.0 parts by weight of an inner wax with respect to 100 parts by weight of the base resin. ,
The heat-radiating coating film is a second organic resin containing 3 to 60 parts by weight of titanium oxide and 0.2 to 15 parts by weight of carbon black as essential heat-dissipating substances with respect to 100 parts by weight of the base resin. A double-side pre-coated aluminum alloy plate excellent in press formability and heat dissipation, characterized in that it is formed by applying and curing a system paint (claim 1).

  The double-side pre-coated aluminum alloy plate of the present invention positively employs an Al—Mg—Cu-based aluminum alloy plate as the substrate. Thereby, it is possible to realize a small size and light weight optimal for an electronic device casing and the like by taking advantage of the characteristics of the Al—Mg—Cu-based aluminum alloy having high strength and excellent formability.

In addition, the double-side pre-coated aluminum alloy plate is provided with the lubricating coating film having excellent lubricity (formability) particularly with a mold on one surface of the substrate, and particularly on the other surface, heat dissipation is emphasized. The heat-radiating coating film is provided. And by using this structure, the outstanding heat dissipation and the outstanding moldability can fully be acquired.
That is, as shown in the processing method described later, by arranging and processing the above-mentioned lubricating coating film on the side particularly requiring lubrication performance at the time of molding, very excellent moldability is achieved by the lubricating action of the inner wax. Can be secured. And about heat dissipation, the heat dissipation excellent also by the effect | action of the heat dissipation substance contained in the said heat dissipation coating film is securable.

For the heat-dissipating coating film, the specific amounts of titanium oxide and carbon black are selected as essential heat-dissipating substances. Thereby, the very outstanding heat dissipation can be ensured, maintaining the moderate moldability in a heat-radiating coating film, and the soundness of a coating film.
Further, the amount of the inner wax contained in the lubricating coating film is also limited to the specific amount. Thereby, very excellent moldability can be secured while maintaining the soundness of the coating film.

A second invention is a method of pressing the double-side precoated aluminum alloy plate of the first invention with a die having a processed hole and a punch that can be inserted into the processed hole.
A press working method characterized in that the surface on which the lubricating coating film is formed on the double-side precoated aluminum alloy plate is positioned on the die side, and the surface on which the heat-radiating coating film is formed is positioned on the punch side. (Claim 14).

  According to this pressing method, as described above, the surface of the double-sided precoated aluminum alloy plate on which the lubricating coating film is formed is positioned on the die side, and the heat dissipating coating film side is positioned on the punch side, and pressing is performed. To do. Therefore, when the press product to be obtained is, for example, a housing, a heat dissipating coating film can be disposed on the inner surface side, that is, the heat source side, and a housing excellent in heat dissipation, that is, heat absorption can be obtained. . In addition, a lubricious coating film can be disposed on the outer surface of the housing, that is, the side in contact with the die during press processing, and is excellent in press moldability and is damaged by the resin beads contained in the lubricating coating film. Adhesion can be prevented, and a housing with excellent design can be obtained. Furthermore, when a pigment-free coating film is disposed between the substrate made of an aluminum alloy plate and the lubricating coating film, the adhesion of the lubricating coating film can be further increased, and the coating film cracking can be further improved. And the occurrence of film peeling and defects can be suppressed.

In the double-side pre-coated aluminum alloy plate of the present invention, as described above, the first organic resin-based paint contains 0.2 to 5.0 parts by weight of inner wax with respect to 100 parts by weight of the base resin. Is used.
When the content of the inner wax is less than 0.2 parts by weight with respect to 100 parts by weight of the base resin, the moldability is deteriorated, and the content of the inner wax exceeds 5.0 parts by weight with respect to 100 parts by weight of the base resin. In such a case, there is a possibility that troubles are likely to occur due to blocking in which the plates are bonded to each other during molding.
Examples of the inner wax include lanolin, carnauba, polyethylene, and the like.

Moreover, as said 2nd organic resin-type coating material, 3-60 weight part of titanium oxide and 0.2-15 weight part of carbon black are contained as an essential heat-radiating substance with respect to 100 weight part of said base resins. Use
When the content of titanium oxide as the heat-dissipating material is less than 3 parts by weight with respect to 100 parts by weight of the base resin, there is a risk that heat dissipation may not be sufficiently obtained, while when it exceeds 60 parts by weight. May increase the proportion of titanium oxide falling off the coating during press molding. Further, if the content of carbon black as a heat-dissipating material is less than 0.2 parts by weight with respect to 100 parts by weight of the base resin, there is a risk that sufficient heat dissipation may not be obtained. There is a possibility that the ratio of carbon black falling off from the coating film during press molding increases.
In addition to the essential heat-dissipating materials such as titanium oxide and carbon black, other heat-dissipating materials such as silica and zirconium oxide can be contained.

Further, the first organic resin-based paint is a polyester resin-based paint containing a base resin composed of a polyester resin having a number average molecular weight of 5000 to 30000 as a main component, and the film of the lubricating coating film after curing. The thickness is preferably 1 to 40 μm (Claim 2).
When the number average molecular weight of the polyester resin is less than 5,000, the coating film becomes too hard and the moldability is deteriorated. On the other hand, when the number average molecular weight exceeds 30,000, the coating film is soft and the scratch resistance may be lowered. .
If the film thickness after curing of the lubricating coating film is less than 1 μm, the moldability is lowered, and if it exceeds 40 μm, the cost may increase.

The second organic resin-based paint is a polyester resin-based paint containing a base resin composed of a polyester resin having a number average molecular weight of 5000 to 30000 as a main component, and the film of the heat-dissipating coating film after being cured. The thickness is preferably 0.5 to 40 μm (Claim 3).
When the number average molecular weight of the polyester resin is less than 5,000, the coating film becomes too hard and the moldability is deteriorated. On the other hand, when the number average molecular weight exceeds 30,000, the coating film is soft and the scratch resistance may be lowered. .
When the film thickness after curing of the heat-dissipating coating film is less than 0.5 μm, there is a problem that the emissivity is low and heat dissipation is inferior, whereas when it exceeds 40 μm, the cost may increase. is there.

  Further, the lubricating coating film preferably contains a heat dissipating material composed of one or more of titanium oxide, carbon black, silica, and zirconium oxide (Claim 4). It is preferable to contain the substance not only in the heat-dissipating coating film but also in the lubricating coating film, thereby further improving the heat-dissipating property.

  Moreover, it is preferable that the heat-radiating coating film contains a conductive substance. Thereby, the said heat-radiation coating film becomes the thing excellent also in electroconductivity in addition to heat dissipation, and the application to the use for which electroconductivity is required is also attained. In addition, since the conductive substance is generally excellent in heat dissipation, the effect of improving heat dissipation can be enhanced.

  The heat-radiating coating film preferably contains resin beads made of particulate synthetic resin. In this case, the scratch resistance can be remarkably improved by the presence of the resin beads.

  In addition, the second organic resin-based paint includes a scaly Ni filler having an average thickness of 0.2 to 5 μm and an average major axis of 2 to 50 μm, or spherical Ni having an average particle diameter of 1 to 40 μm. A conductive substance composed of one or two fillers is contained, and the content thereof is preferably 1 to 70 parts by weight with respect to 100 parts by weight of the base resin.

When the average thickness of the flake-like Ni filler is less than 0.2 μm or the average major axis is less than 2 μm, the conductivity is insufficient. On the other hand, when the average thickness exceeds 5 μm or the average major axis exceeds 50 μm There is a possibility that the rate at which the scaly Ni filler falls off from the coating film increases.
When the average particle size of the spherical Ni filler is less than 1 μm, the conductivity is insufficient, and when it exceeds 40 μm, the proportion of the spherical Ni filler falling off from the coating film during press molding may increase.
When the content of the conductive material (the total when the two types are included) is less than 1 part by weight with respect to 100 parts by weight of the base resin, the conductivity is insufficient, and when the content exceeds 70 parts by weight. May increase the rate at which the conductive material is removed from the coating during press molding.

  The second organic resin-based paint contains resin beads made of particulate synthetic resin having a particle size of 1 to 120 μm and a particle size of 1 to 3 times the film thickness of the heat-dissipating coating film. The content thereof is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the base resin (claim 8).

When the particle size of the resin beads is less than 1 μm, the scratch resistance is insufficient, and when it exceeds 120 μm, there is a possibility that the ratio of the resin beads being removed from the coating film may increase.
If the particle size of the resin beads is less than 1 times the film thickness of the heat-dissipating coating film, scratch resistance may not be obtained sufficiently, while the film thickness of the heat-dissipating coating film may be 3 times the film thickness. When exceeding, there exists a possibility that the ratio which the resin bead falls from a coating film may increase.
When the content of the resin beads is less than 1 part by weight with respect to 100 parts by weight of the base resin, the scratch resistance increases. May increase.

Further, the second organic resin-based paint contains an inner wax, and the content thereof is preferably 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the base resin ( Claim 9).
In this case, the moldability on the side of the heat radiating coating film can be remarkably improved. When the content of the inner wax is 0.5 parts by weight or less with respect to 100 parts by weight of the base resin, the effect of improving the moldability on the heat-dissipating coating film side by the inner wax is small. May increase.

Moreover, it is preferable that the surface of the said board | substrate is formed with the base-treatment layer which improves the adhesiveness of a board | substrate and a coating film (Claim 10).
In this case, since the adhesion between the substrate and the coating film can be enhanced by the presence of the base treatment layer, excellent moldability can be ensured.
As the above-mentioned undercoat layer, conventional chemical coatings such as chromate treatment with chromate chromate or phosphate chromate, non-chromate treatment with titanium phosphate other than chromium compounds, zirconium phosphate, molybdenum phosphate, zinc phosphate, etc. It can be formed by treatment, chemical conversion treatment or the like.

Moreover, it is preferable to have an intermediate coating layer formed by applying and curing a third organic resin-based paint containing no pigment between the lubricating coating and the substrate. Item 11). In this case, due to the presence of the intermediate coating layer, the followability of the coating during molding is improved, and the moldability can be further improved.
Moreover, when the said base treatment layer is provided, the said base treatment layer will exist between a board | substrate and the said intermediate coating film layer.

The third organic resin-based paint is a polyester resin-based paint containing a base resin composed of a polyester resin having a number average molecular weight of 5000 to 30000 as a main component, and the film of the intermediate coating layer after curing. The thickness is preferably 1 to 20 μm (claim 12).
If the number average molecular weight of the polyester resin in the third organic resin-based paint is less than 5000, the coating film becomes too hard and the moldability is deteriorated. On the other hand, if the number average molecular weight exceeds 30000, the coating film is soft. There is a risk of the film peeling off.
When the film thickness of the intermediate coating layer is less than 1 μm, the followability of the coating film at the time of molding may be insufficient, and the moldability may decrease. When the thickness exceeds 20 μm, the cost may increase. is there.

  The substrate contains Mg: 4.0 to 5.5% (mass%, the same applies hereinafter), Cu: 0.25 to 0.45%, and the balance is inevitable impurities and Al. It is preferable that the tensile strength according to a JIS No. 5 test piece is 250 to 350 MPa, the proof stress is 80 to 190 MPa, and the elongation is 20 to 40%.

If the Mg content is less than 4.0%, the predetermined strength may be difficult to obtain, whereas if it exceeds 5.5%, hot rolling may be difficult.
If the Cu content is less than 0.25%, the predetermined strength may be difficult to obtain. On the other hand, if it exceeds 0.45%, the moldability may be inferior and the corrosion resistance may be inferior. .

When the tensile strength is less than 250 MPa, sufficient tensile strength cannot be obtained as a casing, so that molding can be performed, but there is a risk of being easily broken by a subsequent impact or the like. On the other hand, when it exceeds 350 MPa In such a case, there is a risk of being easily broken during press working.
When the proof stress is less than 80 MPa, sufficient proof strength cannot be obtained as a housing, so that although it can be molded, it may be easily deformed by a subsequent impact or the like, whereas when it exceeds 190 MPa, There is a risk of cracking during press working.
If the elongation is less than 20%, there is a risk of being easily broken at the time of press working. On the other hand, if it exceeds 40%, molding is possible, but it is too soft and may be easily deformed by a subsequent impact. There is.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited only to these examples.
In this example, a plurality of types of samples (double-side pre-coated aluminum alloy plates) were produced as examples and comparative examples of the present invention, and their characteristics were evaluated.

  In preparing each sample, first, as a substrate, Mg: 4.0 to 5.5% (mass%, the same applies hereinafter), Cu: 0.25 to 0.45%, and according to JIS No. 5 test piece An aluminum alloy plate having a thickness of 1 mm that satisfies a tensile strength of 250 to 350 MPa, a proof stress of 80 to 190 MPa, and an elongation of 20 to 40% was used.

Further, the substrate was subjected to a ground treatment before coating. Specifically, the substrate was degreased with a commercially available alkaline degreasing agent, and then subjected to phosphoric acid chromate treatment in a phosphoric acid chromate bath. The amount of chromate film is 20 ± 5 mg / m ² as the Cr content in the film.

The coating treatment is performed by applying a predetermined paint to one side of the substrate after the base treatment using a bar coater, and baking in an oven at 240 ° C. for 60 seconds so that the temperature of the aluminum surface becomes 230 ° C. Each coating film was formed by curing. Similarly, a predetermined paint is applied to the other surface using a bar coater, and each coating is performed by baking and curing in an oven at 240 ° C. for 60 seconds so that the temperature of the aluminum surface becomes 230 ° C. A film was formed.
In addition, the formed coating film is shown in Table 1 and Table 2.

  Moreover, the typical structure of the produced sample (double-side pre-coated aluminum alloy plate 1) is shown in FIG. As shown in the figure, each sample is composed of a substrate 10 made of an Al—Mg—Cu-based aluminum alloy plate, a lubricating coating 2 formed on one surface of the substrate 10, and the other surface of the substrate 10. It consists of the formed heat-radiating coating film 3. The lubricious coating film 2 is formed by applying and curing a first organic resin-based paint containing an inner wax, and the heat radiation coating film 3 is a heat radiation material composed of titanium oxide and carbon black. The second organic resin paint containing 35 is applied and cured. Each coating film 2, 3 is formed via a chemical conversion film layer 8 formed on the surface of the substrate 10. Each coating film 2 and 3 may contain Ni filler or resin beads (not shown).

In this example, each sample was evaluated for press formability, heat dissipation (infrared integrated emissivity), electrical conductivity, and scratch resistance, and each of the samples was evaluated as pass 3 or higher.
<Press formability>
The surface on which the lubricious coating film is formed is positioned on the die side, deep drawing is performed under the following conditions, and the maximum depth at which no coating film cracks occur on the die side surface is defined as the molding height. The moldability was evaluated.
(Processing conditions)
Die diameter: φ52.8 mm, punch diameter: φ50 mm, radius of curvature of punch shoulder: 5 mm, radius of curvature of plate pressing die shoulder: 5 mm, plate pressing force: 34 kN, lubricating oil: not used.
(Evaluation criteria)
Level 1: 12 mm or less, Level 2: over 12 mm to 13 mm, Level 3: over 13 mm to 14 mm, Level 4: over 14 mm to 15 mm, Level 5: over 15 mm

<Infrared integrated emissivity>
Infrared integrated emissivity is measured by measuring the infrared reflectance of each wavelength in the range of 2.5-25 μm using PERKIN ELMER FT-IR Spectrometer 1725X, and subtracting the reflected light from the incident light of each wavelength. The absorptivity of each wavelength was defined as reflectance. The reflectance at each wavelength was integrated in the wavelength range of 2.5 to 25 μm to obtain infrared integrated emissivity. The evaluation criteria are as follows, and level 3 or higher was regarded as acceptable.
(Evaluation criteria)
Level 1: Less than 60%, Level 2: 60% or more and less than 70%, Level 3: 70% or more and less than 80%, Level 4: 80% or more and less than 90%, Level 5: 90% or more

<Conductivity>: Used for the evaluation of the conductive paint board. Part of the paint film on the paint board is scraped off with a scraper, and one terminal of the tester is directly connected to the aluminum substrate. A spherical electrode having a weight of 100 g was connected to the electrode, and the electrode was supported by an auxiliary tool so as to contact the painted plate vertically. The electrical resistance value at that time was read and used for evaluation. The evaluation criteria are as follows, and level 3 or higher was regarded as acceptable.
(Evaluation criteria)
Level 1: 1000Ω or more, Level 2: 500Ω or more and less than 1000Ω, Level 3: 50Ω or more and less than 500Ω, Level 4: 10Ω or more and less than 50Ω, Level 5: Less than 10Ω

<Scratch resistance>: Used for evaluation of scratch-resistant coated plate In the Bowden test, the width of a sliding trace when a steel ball having a load of 500 g and a 1/4 inch was slid 100 times was used for evaluation. The evaluation criteria are as follows, and level 2 or higher was regarded as acceptable.
(Evaluation criteria)
Level 1: 1.0 mm or more, Level 2: 0.5 mm or more and less than 1.0 mm, Level 3: 0.3 mm or more and less than 0.5 mm, Level 4: 0.1 mm or more and less than 0.3 mm, Level 5: 0.1 Less than

  The results of evaluation are as shown in Table 3.

Explanatory drawing which shows the structure of the double-sided precoat aluminum alloy plate in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Double-sided precoat aluminum alloy plate excellent in press moldability and heat dissipation 10 Substrate 2 Lubricant coating 3 Heat dissipation coating 35 Heat dissipation material

Claims (14)

It consists of a substrate made of an Al-Mg-Cu-based aluminum alloy plate, a lubricating coating film formed on one surface of the substrate, and a heat dissipating coating film formed on the other surface of the substrate,
The lubricating coating is formed by applying and curing a first organic resin-based paint containing 0.2 to 5.0 parts by weight of an inner wax with respect to 100 parts by weight of the base resin. ,
The heat-radiating coating film is a second organic resin containing 3 to 60 parts by weight of titanium oxide and 0.2 to 15 parts by weight of carbon black as essential heat-dissipating substances with respect to 100 parts by weight of the base resin. A double-sided pre-coated aluminum alloy plate excellent in press formability and heat dissipation, characterized in that it is formed by applying and curing a system paint.   2. The first organic resin-based paint according to claim 1, wherein the first organic resin-based paint is a polyester resin-based paint containing a base resin made of a polyester resin having a number average molecular weight of 5000 to 30000 as a main component. A double-side pre-coated aluminum alloy plate excellent in press formability and heat dissipation, wherein the film thickness is 1 to 40 μm.   3. The heat radiation after curing according to claim 1 or 2, wherein the second organic resin-based paint is a polyester resin-based paint containing as a main component a base resin made of a polyester resin having a number average molecular weight of 5000 to 30000. A double-sided precoated aluminum alloy plate excellent in press formability and heat dissipation, characterized in that the film thickness of the adhesive coating is 0.5 to 40 μm.   4. A heat-dissipating material comprising one or more of titanium oxide, carbon black, silica, and zirconium oxide in the lubricating coating film according to claim 1. A double-sided pre-coated aluminum alloy plate excellent in press formability and heat dissipation.   5. The double-side precoated aluminum alloy plate excellent in press formability and heat dissipation, wherein the heat dissipating coating film contains a conductive substance in any one of claims 1 to 4.   The double-sided precoated aluminum excellent in press formability and heat dissipation, characterized in that the heat dissipation coating film contains resin beads made of particulate synthetic resin in any one of claims 1-5. Alloy plate.   In any one of Claims 1-6, scaly Ni filler which has an average thickness of 0.2-5 micrometers and an average major axis of 2-50 micrometers in said 2nd organic resin-type coating material, or 1- A conductive material composed of one or two spherical Ni fillers having an average particle diameter of 40 μm is contained, and the content thereof is 1 to 70 parts by weight with respect to 100 parts by weight of the base resin. A double-sided precoated aluminum alloy plate excellent in press formability and heat dissipation.   8. The particle according to claim 1, wherein the second organic resin-based paint has a particle diameter of 1 to 120 μm and a particle diameter of 1 to 3 times the film thickness of the heat radiation coating film. A double-sided precoat excellent in press moldability and heat dissipation, characterized in that resin beads made of a synthetic resin are contained and the content thereof is 1 to 100 parts by weight with respect to 100 parts by weight of the base resin. Aluminum alloy plate.   In any 1 item | term of Claims 1-8, the inner wax is contained in the said 2nd organic resin-type coating material, The content is 0.5-5 with respect to 100 weight part of said base resins. A double-side precoated aluminum alloy plate excellent in press formability and heat dissipation, characterized by being 0.0 part by weight.   In any 1 item | term of Claims 1-9, in the surface of the said board | substrate, the base-treatment layer which improves the adhesiveness of a board | substrate and a coating film is formed. Excellent double-sided pre-coated aluminum alloy sheet.   The intermediate coating film formed by applying and curing a pigment-free third organic resin coating material between the lubricating coating film and the substrate according to any one of claims 1 to 10. A double-side pre-coated aluminum alloy plate excellent in press formability and heat dissipation, characterized by having a layer.   12. The intermediate coating film according to claim 11, wherein the third organic resin-based paint is a polyester resin-based paint containing, as a main component, a base resin made of a polyester resin having a number average molecular weight of 5000 to 30000. A double-sided precoated aluminum alloy plate excellent in press formability and heat dissipation, characterized in that the layer thickness is 1 to 20 μm.   In any 1 item | term of Claims 1-12, the said board | substrate contains Mg: 4.0-5.5% (mass%, hereafter the same), Cu: 0.25-0.45%, The remainder is It consists of inevitable impurities and Al, and is excellent in press formability and heat dissipation, characterized by a tensile strength of 250 to 350 MPa, a proof stress of 80 to 190 MPa, and an elongation of 20 to 40% according to a JIS No. 5 test piece. Double-sided pre-coated aluminum alloy plate. In the method of press-working the double-sided pre-coated aluminum alloy plate according to any one of claims 1 to 13, with a die having a processed hole and a punch that can be inserted into the processed hole.
A press working method characterized in that the surface on which the lubricating coating film is formed on the double-side precoated aluminum alloy plate is positioned on the die side, and the surface on which the heat-radiating coating film is formed is positioned on the punch side. .

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