KR20170049410A - Small electronic apparatus case and aluminum alloy rolling laminated plate for small electronic apparatus case - Google Patents

Abstract

The present invention provides a small electronic apparatus case, capable of being efficiently formed at low costs by drawing; difficult to cause defects during formation; scratches not remained on a surface by forming; and having excellent appearance. According to the present invention, an aluminum alloy rolled laminated plate is formed in the small electronic apparatus case by drawing, comprising: an aluminum alloy rolled plate with 0.2% durability over 200 Mpa; and a cladding stacked on one or both surfaces of the aluminum alloy rolled plate. The cladding is made of a synthetic resin film or a laminate stacking a synthetic resin on both surface of a metal film. The aluminum alloy rolled plate has a fibrous crystalline structure extended in a direction perpendicular to a thickness direction.

Description

TECHNICAL FIELD [0001] The present invention relates to a compact electronic device case, a molding method thereof, and an aluminum alloy rolled laminated plate for a small electronic device case.

INDUSTRIAL APPLICABILITY The present invention relates to a case of a small electronic device such as a tablet terminal, a portable communication terminal device, a notebook type personal computer, a portable telephone, a portable music device, a digital camera, a molding method thereof, To an aluminum alloy rolled laminated sheet.

BACKGROUND ART Conventionally, it is known that a case of a small electronic device is formed by cutting (machining the entire surface) an aluminum alloy extruded material (extruded material) of a thick plate shape (see, for example, Patent Document 1).

The case described above is suitably used as a compact electronic device case because it can obtain excellent appearance, precision, and strength.

In addition, generally, drawing processing is also widely used as a means for molding a predetermined shape product from a metal plate material such as an aluminum alloy plate material (plate material).

Japanese Patent Application Laid-Open No. 2012-246555 (JP2012-246555A)

However, in the case of a small-sized electronic device formed by cutting, since the time required for cutting the material is long, the manufacturing efficiency is low, and a large amount of cutting debris is generated along with the machining , It takes a lot of energy to recover it, which results in a high cost.

On the other hand, in the case of drawing processing, since the molding is performed in a short time, the manufacturing efficiency is excellent, and since no debris accompanies the processing, there can be produced at low cost. However, the case of the small electronic device case generally has a bottom wall having a substantially rectangular shape in plan view, and side walls erected from the periphery of the bottom wall. If a case of such a shape is tried to be formed by drawing, there is a possibility that a crack will be generated in the corner portion of the side wall, resulting in defective molding.

In addition, in the case of drawing, the surface of the metal plate slidably contacts with the metal mold, thereby causing scratches on the surface of the metal mold, thereby damaging the appearance of the product.

It is an object of the present invention to provide a compact electronic device case which can be efficiently and inexpensively formed by drawing processing and which is less prone to defective molding and does not cause scratches on its surface due to molding and has an excellent appearance .

In order to achieve the above object, the present invention comprises the following aspects.

1) An aluminum alloy rolled laminate plate for forming a case of a small electronic device by drawing processing, comprising: an aluminum alloy rolled plate having a 0.2% proof stress of 200 MPa or more; and an aluminum alloy rolled plate material having a 0.2% And the covering material is composed of a synthetic resin film and a laminate in which a synthetic resin film is laminated on both surfaces of the metal foil. The aluminum alloy rolled laminated sheet for a small electronic device case.

(2) The aluminum alloy rolled laminated sheet for a compact electronic device case according to (1), wherein the aluminum alloy rolled plate has a fibrous crystalline structure stretched in a direction perpendicular to the thickness direction.

3) The aluminum alloy rolled plate is an Al-Mn-Mg alloy composed of 0.2 to 0.7% by mass of Mn, 2.0 to 5.0% by mass of Mg, Al and inevitable impurities, Si: Mg-Al-based alloy consisting of Al and unavoidable impurities, and Al: Si-Mg-based alloy composed of Al and unavoidable impurities in an amount of 0.5 to 3.0 mass%, Mg: 0.4 to 1.2 mass% The aluminum alloy rolled laminated sheet for a compact electronic device case according to 1) or 2), wherein the laminated sheet is made of any one of Al-Zn-Mg alloys.

4) The aluminum alloy rolled laminated sheet for a compact electronic device case according to any one of 1) to 3) above, wherein the thickness of the covering material is 0.05 to 1.5 times the thickness of the aluminum alloy rolled plate.

(5) The aluminum alloy rolled laminated sheet for a small electronic appliance case as described in any one of (1) to (4) above, wherein the thickness of the aluminum alloy rolled plate is 0.5 to 3.5 mm.

6) A laminate of a laminate of a polyester resin film or a polyamide resin film having a thickness of 50 to 100 占 퐉 laminated on a surface of an aluminum alloy rolled plate, Aluminum alloy rolled laminated sheet for any small electronic appliance case.

7) A method for producing a rolled aluminum alloy rolled sheet as described in 1) above, wherein a covering material composed of a polyethylene resin film, a polypropylene resin film or a polyamide resin film having a thickness of 10 to 100 μm is laminated on the inner surface side of a small- To (6), respectively, of the aluminum alloy rolled laminated plate.

(8) A method for producing a laminate comprising the step of drawing an aluminum alloy rolled laminated plate for a small electronic device case of any one of (1) to (7) above, wherein at least one of both inner and outer surfaces is covered with a covering material comprising a synthetic resin film or a laminate Small electronic case.

9) A compact electronic device case, which is obtained by drawing an aluminum alloy rolled laminated plate for a small electronic device case of any one of 1) to 7) above, and then removing the covering material covering at least one of the inner and outer surfaces.

10) The small electronic device case of 9) above, wherein the bottom wall has a side wall erected at the periphery of the bottom wall, the height of the side wall is 0.5 to 25 mm, and the angle of the side wall to the bottom wall is 90 to 150 degrees.

11) A method of forming a compact electronic device case for drawing an aluminum alloy rolled laminated plate for a small electronic device case of any one of 1) to 7) above.

According to the aluminum alloy rolled laminated sheet for a small electronic device case of 1) above, since the 0.2% proof stress of 200 MPa or more is used as the aluminum alloy rolled plate to be the material of the case, the strength of a desired case is secured.

Further, according to the aluminum alloy rolled laminated sheet of 1), a synthetic resin film or a synthetic resin film is laminated on both surfaces of a metal foil on at least one side of both surfaces of the rolled aluminum alloy sheet, It is possible to prevent wrinkles on the side walls of the case formed by the drawing process or cracks on the corner portions of the side walls and to suppress the occurrence of defective molding, The surface of the case is prevented from being scratched, and the appearance of the case is not damaged.

According to the aluminum alloy rolled laminated sheet for a small electronic device case of 2) above, since the aluminum alloy rolled plate has a fibrous crystal structure stretched in the direction perpendicular to the thickness direction, the strength of the plate material against bending increases, Molding defects such as cracks are unlikely to occur.

According to the aluminum alloy rolled laminated sheet for a small electronic device case of the above item 3), the aluminum alloy rolled plate is made of an Al-Mn-Mg alloy, Al-Si-Mg alloy or Al-Zn- It is possible to obtain a case having high precision and high strength and excellent appearance because it is made of any one of the aluminum alloys.

According to the aluminum alloy rolled laminated sheet for a small electronic device case of 4) above, since the thickness of the covering material is 0.05 to 1.5 times the thickness of the aluminum alloy rolled plate, the following problems are avoided.

That is, when the thickness of the covering material is less than 0.05 times the thickness of the aluminum alloy rolled plate, the covering material is broken, and a portion where the molded article contacts the metal is scratched. On the other hand, even if the thickness of the covering material exceeds 1.5 times the thickness of the aluminum alloy rolled plate, no further effect can be obtained and the cost is only increased.

According to the aluminum alloy rolled laminated sheet for a small electronic device case of 5) above, since the thickness of the aluminum alloy rolled plate is 0.5 to 3.5 mm, the following problems are avoided.

That is, when the thickness of the aluminum alloy rolled plate material is less than 0.5 mm, the strength of the final product is insufficient. On the other hand, when the thickness of the aluminum alloy rolled plate exceeds 3.5 mm, the radius of curvature R of the bent portion or the corner portion becomes too large.

According to the aluminum alloy rolled laminated sheet for a small electronic device case of the item 6), the following effects can be obtained. That is, when the aluminum alloy rolled laminated plate is drawn to form a case of a small electronic device, the surface of the small-sized electronic equipment case, which is the outer surface of the case, is partially scratched by a mold, When a polyester resin film or a polyamide resin film having a thickness of 50 to 100 占 퐉 is used, scratches on the surface of the molded article can be reliably avoided because the resin does not break due to squeezing of the mold, The increase in cost due to too large is suppressed, and further, the rigidity of the film is so large that the case can be prevented from being lifted or peeled off from the bend-molded portion.

According to the aluminum alloy rolled laminated sheet for a compact electronic device case of 7), the following effects can be obtained. That is, when the small-sized electronic equipment case is formed by drawing the aluminum alloy rolled laminated plate material, the inner surface of the small electronic equipment case on both sides of the plate material is not scratched by the metal mold, A polyethylene resin film, a polypropylene resin film, or a polyamide resin film having a thickness of 10 to 100 占 퐉 is used as the covering material for covering this surface, the rigidity of the film is too large to allow the case to be lifted up at the bend- And it is also possible to avoid the situation that the case is prevented from being peeled off or the case where the curvature radius R of the bend-molded portion becomes large, and a sharp shape can not be obtained.

According to the case (8) of the small electronic device case with the covering material, since the aluminum alloy rolling plate material is well formed by the drawing process and the surface is not scratched during the molding, Can be obtained.

In addition, according to the case (8) of the small electronic device case with the covering material, since the surface of the case is covered with the covering material, the surface is prevented from being scratched during storage or transportation.

According to the case (9) of the small-sized electronic device described above, the aluminum alloy rolling plate is well formed by drawing, and the surface is not scratched during molding, storage or transportation. A case showing a beautiful appearance while having it can be obtained.

According to the small electronic apparatus case of 10), the height of the side wall is 0.5 to 25 mm, and the angle of the side wall to the bottom wall is 150, so that the following problems are avoided.

That is, if the height of the sidewall is less than 0.5 mm, the number of cutting portions increases in the subsequent step. On the other hand, if the height of the side wall exceeds 25 mm, the thickness of the small electronic device becomes large, which is not preferable.

Further, when the angle of the sidewall with respect to the bottom wall is less than 90 占, that is, when the sidewall is inclined inward, wrinkles are generated in the corner portion, and processing becomes difficult. On the other hand, if the angle of the sidewall with respect to the bottom wall exceeds 150, the depth of the case becomes shallow, and the accommodating volume of a component of a small electronic apparatus is reduced.

According to the molding method of the compact electronic device case described in the above 11), it is possible to efficiently and low-costly mold a small electronic device case having a high precision and strength while exhibiting a beautiful appearance by drawing.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partially enlarged cross-sectional view showing a layer structure of an aluminum alloy rolled laminated sheet for a case of a small electronic device according to the present invention. Fig.
Fig. 2 is a vertical cross-sectional view sequentially showing a step of drawing a plate material to form a compact electronic device case. Fig.
3 is a perspective view of a compact electronic device case according to the present invention;
4 is a perspective view for showing a cross-sectional direction when a fibrous crystal structure of a cross section is observed by bending an aluminum alloy rolled plate.
5 is a photomicrograph of a cross section (90 ° in the direction of the cross section in the rolling direction) of the bending material (inner arrays (R) 0 mm) of this aluminum alloy rolled plate material.
6 is a microscope photograph of a cross section of the bending material (inner diameter of 0.4 mm) of this aluminum alloy rolled plate material (cross direction in the rolling direction: 90 °).
7 is a photomicrograph of a cross-section (cross-sectional direction in the rolling direction: 0 °) of the bending material (internal diameter of 0 mm) of the aluminum alloy rolled plate material.
8 is a photomicrograph of a cross section (cross direction in the rolling direction: 0 DEG) of the bending material (inner diameter 0.4 mm) of this aluminum alloy rolled plate material.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to Figs.

Fig. 1 shows the layer structure of an aluminum alloy rolled laminated sheet 1 for a case for a small electronic device according to the present invention.

As shown in the figure, the aluminum alloy rolled laminate plate 1 for a small electronic device case is composed of an aluminum alloy rolled plate material 2 and coating materials 3 and 4 laminated on both surfaces of the aluminum alloy rolled plate material 2 .

As the aluminum alloy rolled plate 2 described above, a 0.2% proof stress of 200 MPa or higher, preferably 250 MPa or higher, and more preferably 300 MPa or higher is used. Thereby, the desired case strength can be obtained. The aluminum alloy rolled plate 2 preferably has a breaking elongation of 5% or more and 20% or less. This improves the formability of the drawing process. Here, "0.2% proof stress" and "elongation at break" are obtained by a tensile test in the direction parallel to the rolling direction using No. 5 test specimen specified in JIS Z2241-2011.

Further, the aluminum alloy rolled plate 2 has a fibrous crystal structure stretched in the direction perpendicular to the thickness direction.

The fibrous crystal structure is formed by subjecting the aluminum alloy ingot subjected to homogenization treatment to hot rolling followed by heat treatment under a predetermined condition and then cold rolling. The heat treatment is carried out at 200 to 400 占 폚 for 1 hour or longer. By the heat treatment, Mg ₂ Si can be uniformly precipitated finely and the processing distortion present in the rolled material can be reduced. It is possible to obtain an aluminum alloy rolled plate of high strength within a range that does not impair the subsequent forming workability.

The conditions for the homogenization treatment of the aluminum alloy ingot are not particularly limited, and it is preferable to carry out the homogenization treatment at 500 ° C or more for 2 hours or more according to a usual method.

In the hot rolling, an effect equivalent to quenching is obtained by a temperature drop during rolling at a predetermined temperature condition in an optional pass step. Therefore, the material temperature before the pass requires a temperature at which Mg and Si can be maintained in a solid state, and is set to 350 to 440 캜. In order to set the pass finishing temperature to the temperature range of 200 to 400 占 폚, forced cooling such as high-pressure shower water cooling may be immediately performed in the hot rolling finish. In order to obtain the quenching effect, the cooling rate between the passes is 50 占 폚 / min or more, the pass finishing temperature is 250 to 340 占 폚, the pass rolling speed is 50 m / min or more, and the finishing plate thickness is 10 mm or less.

In the cold rolling, a reduction ratio of 30% or more is used in order to obtain a predetermined strength by work hardening. The preferable reduction rate is 50% or more.

Further, the cold-rolled alloy sheet can be finally annealed at a temperature of 130 to 150 캜, if necessary. By performing the heat treatment at a low temperature, it is possible to cure the steel material effectively, thereby further improving the strength and improving the elongation. It also has the effect of stabilizing various mechanical properties.

As the aluminum alloy rolled plate 2, any one of the following aluminum alloys is suitably used.

i) an Al-Mn-Mg alloy alloy containing 0.2 to 0.7% by mass of Mn and 2.0 to 5.0% by mass of Mg, the balance being Al and inevitable impurities

Ii) an Al-Si-Mg alloy containing 0.2 to 0.8% by mass of Si and 0.4 to 1.2% by mass of Mg, the balance being Al and inevitable impurities

Iii) an Al-Zn-Mg alloy alloy containing 4.0 to 6.5% by mass of Zn and 0.5 to 3.0% by mass of Mg, the balance being Al and inevitable impurities

The alloy of i) is preferably at least one selected from the group consisting of 0.4 mass% or less of Si, 0.4 to 0.6 mass% of Mn, 4.0 to 4.9 mass% of Mg, 0.4 mass% or less of Fe, 0.05 to 0.25 mass% of Cr, Or less, and the balance Al and an aluminum alloy comprising inevitable impurities.

The alloy of ii) above preferably contains 0.2 to 0.6 mass% of Si, 0.45 to 0.9 mass% of Mg, 0.35 mass% or less of Fe, 0.1 mass% or less of Cr and 0.1 mass% or less of Zn, And an aluminum alloy composed of inevitable impurities.

The alloy of iii) above preferably contains 0.4 mass% or less of Si, 2.1 to 2.9 mass% of Mg, 0.5 mass% or less of Fe, 1.2 to 2.0 mass% of Cu, 0.3 mass% or less of Mn, 0.18 to 0.28 mass% %, And Zn: 5.1 to 6.1 mass%, and the remainder Al and inevitable impurities.

Of these, in particular, the alloy contains 0.2 to 0.6 mass% of Si, 0.45 to 0.9 mass% of Mg, 0.35 mass% or less of Fe, 0.1 mass% or less of Cr and 0.1 mass% or less of Zn, Is suitable as a molding material for a small-sized electronic equipment case. The aluminum alloy rolling plate 2 is made of an aluminum alloy.

The thickness of the aluminum alloy rolled plate 2 to be used is appropriately set in accordance with the molding conditions and the size of the case, which is a molded product, but is preferably 0.5 to 3.5 mm, more preferably 0.8 to 1.2 mm.

The covering materials 3 and 4 improve the formability at the time of drawing the aluminum alloy rolled plate 2 and reduce the use of the lubricant at the time of molding and further reduce the surface of the plate material 2 And further protects the case surface after the case molding, for example, during storage or transportation.

As shown in Fig. 1 (a), as the covering material 3 (4), a laminated body of synthetic resin films 32, 33, 42 and 43 is laminated on both surfaces of the metal foil 31 The synthetic resin films 30 and 40 may be used as shown in Fig. 1 (b).

As the metal foil 31 (41) of the laminate 3 (4) constituting the covering material in the aluminum alloy rolled laminate plate 1 for a small electronic device case of the first embodiment shown in Fig. 1 (a) Foil, stainless steel foil, and copper foil. As the synthetic resin films 32, 33, 42 and 43 of the layered product 3 and 4, an unoriented polypropylene resin film (CPP), a polyethylene terephthalate resin film (PET) A nylon resin film (Ny), a polyimide resin film (PI), a polyethylene resin film (PE), or a stretched film thereof. The lamination of the metal foils 31 and 41 and the synthetic resin films 32, 33, 42 and 43 can be formed by using a laminate of a polyester urethane resin (PAUR), an acrylic resin, an acid modified polyolefin resin (APO) (Not shown).

In the aluminum alloy rolled laminated sheet 1 for a small electronic device case of the second embodiment shown in Fig. 1 (b), the synthetic resin films 30 and 40 constituting the covering materials 3 and 4 are provided with, for example, , A polypropylene resin film, a polyester resin film, a polyamide resin film, a polyimide resin film, and a polyethylene resin film are preferably used, and a biaxially oriented polyethylene terephthalate resin film (PET), a biaxially oriented nylon resin film ONy), polyethylene resin film, biaxially oriented polyamide resin film, biaxially oriented polypropylene resin film (OPP), unstretched polypropylene resin film (CPP) and unoriented nylon resin film (CNy) do.

A synthetic resin film 30 having a thickness of 10 to 200 占 퐉 is laminated on the cover material 3 to be laminated on the side (the lower side in Fig. 1 (b)) of the both surfaces of the aluminum alloy rolled plate 2, It is preferable to use a synthetic resin film 40 having a thickness of 10 to 100 mu m for the covering material 4 to be laminated on the inner surface of the case of the electronic device (the upper surface in Fig. 1B) Do.

More suitably, the covering material 3 to be laminated on the surface (the lower surface in Fig. 1 (b)) of the both surfaces of the aluminum alloy rolled plate 2 which becomes the outer surface of the case of the small electronic device is made of a polyester resin (PET), a biaxially oriented polyethylene naphthalate resin film (PEN), or a biaxially oriented polyimide resin film 6 having a thickness of 50 to 100 占 퐉, and more preferably a biaxially oriented polyethylene terephthalate resin film - nylon resin film (ONy) 30. As the film 30, those having a tensile strength of 180 to 330 MPa and a tensile elongation at break of 80 to 180% can be suitably used. Among them, a film 30 having a ratio of MD / TD of tensile strength or tensile elongation at break ranging from 0.8 to 1.2 can be suitably used.

The cover material 4 laminated on the surface (the upper surface in Fig. 1 (b)) of the both surfaces of the aluminum alloy rolled plate 2 that becomes the inner surface of the case of the small electronic device has a thickness of 10 to 100 탆 (more preferably 20 Polypropylene resin film or polyamide resin film, and more preferably an unoriented polyethylene resin film, an unoriented polypropylene resin film (CPP), a stretched polypropylene film A resin film (OPP), or a stretched nylon resin film (ONy) 40. The film 40 having a Young's modulus of 30 to 400 MPa can be suitably used.

The covering material may be laminated on at least one surface of both surfaces of the aluminum alloy rolled plate 2, more specifically, the surface constituting the outer surface of the case. However, it is preferable to improve the formability and to protect the surface of the case It is preferable to laminate on both sides of the aluminum alloy rolled plate 2 as shown in Fig.

In the case of laminating the cover material on both sides of the aluminum alloy rolled plate material 2, the two cover materials laminated on each side may be the same or different materials / thicknesses.

In the case where the aluminum alloy rolled plate 2 has a small bending strength or a small thickness, the synthetic resin films 30 and 40 may be used as the covering material (see Fig. 1 (b) 2) or the thickness thereof is large, when a synthetic resin film is used as a covering material, it is likely to be broken at the time of drawing processing and wrinkle may be generated on the surface of the molded article. (See Fig. 1 (a)).

Considering that it is necessary to remove the cover materials 3 and 4 from the surface after the case molding, the lamination of the cover materials 3 and 4 on the surface of the aluminum alloy rolled plate 2 is not limited to the configuration shown in Fig. 1 Likewise, it is preferable to be carried out through the pressure-sensitive adhesive layers 34 and 44. As the pressure-sensitive adhesive layers 34 and 44, for example, urethane pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, and rubber pressure-sensitive adhesives are used. The adhesive strength of the pressure-sensitive adhesive layers 34 and 44 to the aluminum alloy rolled plate 2 is preferably 0.5 to 15 N / 25 mm (more preferably 1 to 10 N / 25 mm). Here, the " adhesive force " is represented by a peel strength of 180 DEG in accordance with JIS Z0237: 2000. When the adhesive strength of the pressure-sensitive adhesive layers 34 and 44 is less than 0.5 N / 25 mm, the aluminum alloy rolled plate material 2 to the covering material 3 (4 The adhesive strength of the pressure-sensitive adhesive layers 34 and 44 exceeds 15 N / 25 mm, the workability in peeling and removing the covering materials 3 and 4 after the case molding is lowered In addition, a part of the pressure-sensitive adhesive may remain on the surface of the case, which may result in inadequacy in the polishing of the post-process.

The thickness of the covering materials 3 and 4 is preferably 0.05 to 1.5 times the thickness of the aluminum alloy rolled plate 2 and more preferably 0.2 to 1.0 times the thickness of the aluminum alloy rolled plate 2.

Fig. 2 shows a step of drawing the aluminum alloy rolled laminated plate 1 to form a compact electronic device case.

First, a roughly rectangular aluminum alloy rolled laminate 1 cut to a predetermined dimension is set on the upper surface of a fixed die (female die) 5 on the lower side of the die (see Fig. 2 (a)). A lubricant made of, for example, a silicone-based lubricant, a mineral oil, or a synthetic petroleum-based lubricant is applied to the lower surface of the lower cover material 3 at least on the upper and lower surfaces of the aluminum alloy rolled laminate plate 1, It is preferable to apply the resin composition to the mold, thereby further improving the moldability.

When the movable punch 6 on the upper side of the mold is lowered, a portion of the rolled aluminum alloy laminated plate 1 except for the peripheral edge portion thereof is pressed downward at the tip end of the male mold 6, The straight portion of the periphery is bent upward, and the corner portion of the periphery is drawn and formed (see Fig. 2 (b)). At this time, since the aluminum alloy rolled plate 2 is covered with the covering materials 3 and 4 on both sides thereof, generation of wrinkles is suppressed, and as a result, cracks do not occur. Further, the surface of the aluminum alloy rolled plate 2 does not directly contact with the female mold 5 and the male mold 6, and therefore, the surface of the aluminum alloy rolled plate 2 is not torn and scratched.

Thus, a small electronic device case 20 with the covering material 3 (4) is obtained. Since the surface of the small electronic device case 20 is covered with the covering materials 3 and 4, for example, it does not come in contact with other objects during storage or transportation, and is kept in a beautiful state.

Fig. 3 shows a compact electronic device case 20. The case 20 is obtained by peeling off the covering materials 3 and 4 from both the inner and outer surfaces of the small electronic device case 20 with the covering materials 3 and 4 and then finishing , And also by anodizing the surface.

The small electronic device case 20 is constituted by a roughly rectangular bottom wall 21 as viewed in a plan view and four side walls 22 erected at four sides of the bottom wall 21 respectively. The end portions of the adjacent side walls 22 are continuous with each other and the bottom wall 21 is surrounded by the four side walls 22.

The height of the side wall 22 (in other words, the forming height) is 0.5 to 25 mm, preferably 1 to 15 mm, more preferably 2 to 10 mm.

The angle of the side wall 22 with respect to the bottom wall 21 is 90 to 150 DEG (about 90 DEG in the drawing), preferably 90 to 120 DEG, and more preferably 90 to 100 DEG.

Arrangement is attached to the boundary between the bottom wall 21 and the side wall 22 and also to the corner 22a of the side wall 22. In these arcuate portions, the crystal structure of the fibrous phase is increased to conform to the arcs.

The fibrous crystal structure can be confirmed by observing a cross section of the case 20 in which the aluminum alloy rolled plate 2 or the aluminum alloy rolled plate 2 is drawn by using a polarization microscope.

Preferably, the fibrous crystal structure is also observed in a cross section cut in an arbitrary direction such as 0 deg., 90 deg., 45 deg., 135 deg. Relative to the rolling direction of the aluminum alloy rolled plate material. The same can be observed at the bent portion and the corner portion.

Specifically, for example, as shown in Figs. 4 (a) and 4 (b), an aluminum alloy rolled plate 2 having a thickness of 0.25 mm is subjected to bending processing so as to have an inner radius of 0 mm or 0.4 mm And a cross section of these bending members cut in a direction of 90 占 (right angle) or 0 占 (parallel) with respect to the rolling direction X is observed with a polarization microscope. Then, as can be seen from the micrographs of FIGS. 5 to 8, the cross-sectional direction with respect to the rolling direction is 90 占 (Fig. 5), 0.4 mm with respect to the rolling direction, (Fig. 6), 0 mm in width, 0 mm in cross direction to the rolling direction (Fig. 7), 0.4 mm in inner diameter and 0 Extends in a direction perpendicular to the thickness direction of the plate material in accordance with the arcs.

[Example]

Next, a specific embodiment of the present invention will be described. However, the present invention is not limited to these examples.

<Example 1>

Wherein the aluminum alloy ingot is composed of 0.2 to 0.6 mass% of Si, 0.45 to 0.9 mass% of Mg, 0.35 mass% or less of Fe, 0.1 mass% or less of Cr and 0.1 mass% or less of Zn, Was homogenized at 580 占 폚 for 10 hours and then subjected to preliminary heating at 500 占 폚 to start hot rolling. The final pass starting temperature of hot rolling was set at 400 캜, and after passing, it was cooled at a rate of 80 캜 / min. Thereafter, heat treatment was performed at 240 DEG C for 4 hours. Thereafter, cold rolling was carried out at a reduction ratio of 86%. Thus, an aluminum alloy rolled plate having a 0.2% proof stress of 310 MPa and an elongation at break of 7% and a thickness of 1 mm was obtained.

The cross section of the plate was observed by an optical microscope and a polarizing lens, and a fibrous crystal structure extending in a direction perpendicular to the thickness direction was observed.

An unoriented polypropylene resin film having a thickness of 30 占 퐉 was laminated on one surface of an aluminum foil having a thickness of 120 占 퐉 as a covering material on the lower surface of an aluminum alloy rolled plate constituting the outer surface of the case of a small electronic device with a polyester urethane resin and a hexamethylene di An isocyanate-containing adhesive layer and a laminate of an unstretched polypropylene resin film having a thickness of 200 mu m on the other surface thereof with an adhesive layer were laminated through a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive.

Further, a nylon resin film having a thickness of 30 mu m was laminated on the upper surface of the aluminum alloy rolled plate constituting the inner surface of the case of the small electronic device through a pressure-sensitive adhesive layer composed of an acrylic pressure-sensitive adhesive as a covering material.

The aluminum alloy rolled laminated sheet material thus obtained was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width, and 4.5 mm in corner portions to prepare the molding material of Example 1.

<Practical Example 2>

0.4 to 0.9 mass% of Si, 0.4 to 0.6 mass% of Mn, 4.0 to 4.9 mass% of Mg, 0.4 mass% or less of Fe, 0.05 to 0.25 mass% of Cr and 0.25 mass% or less of Zn, And inevitable impurities were homogenized at 580 占 폚 for 10 hours and then subjected to preliminary heating at 500 占 폚 and hot rolling was started. The final pass starting temperature of hot rolling was set at 400 캜, and after passing, it was cooled at a rate of 80 캜 / min. Thereafter, heat treatment was performed at 240 DEG C for 4 hours. Thereafter, cold rolling was performed at a reduction ratio of 79%, and then final annealing was performed at 130 캜 for 4 hours. Thus, an aluminum alloy rolled plate having a thickness of 1.5 mm with 0.2% proof stress of 210 MPa and elongation at break of 7% was obtained.

The cross section of the sheet material was observed with an optical microscope and a deflecting lens, and a fibrous crystal structure extending in a direction perpendicular to the thickness direction was observed.

A nylon resin film having a thickness of 90 mu m was laminated on both upper and lower surfaces of the aluminum alloy rolled plate through a pressure-sensitive adhesive layer composed of an acrylic pressure-sensitive adhesive.

The aluminum alloy rolled laminated sheet material thus obtained was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width and 4.5 mm in corner portions to prepare the molding material of Example 2.

&Lt; Example 3 >

Wherein the alloy includes at least one of Si: 0.4 mass% or less, Mg: 2.1 to 2.9 mass%, Fe: 0.5 mass% or less, Cu: 1.2 to 2.0 mass%, Mn: 0.3 mass% or less, Cr: 0.18 to 0.28 mass% Aluminum alloy ingot consisting of Al and unavoidable impurities was rolled under the same process and conditions as in Example 2 to obtain an aluminum alloy having a 0.2% proof stress of 550 MPa and a breaking elongation of 9% To obtain a rolled plate material.

The cross section of the sheet material was observed with an optical microscope and a deflecting lens, and a fibrous crystal structure extending in a direction perpendicular to the thickness direction was observed.

Then, a nylon resin film having a thickness of 90 占 퐉 was laminated as a covering material on the lower surface of the aluminum alloy rolling plate constituting the outer surface of the case of the small electronic device through a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive.

The thus obtained aluminum alloy rolled laminated plate was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width and 4.5 mm in corner portions to prepare the molding material of Example 3.

<Example 4>

An aluminum alloy rolled plate similar to that of Example 1 was prepared.

Then, a nylon resin film having a thickness of 90 占 퐉 was laminated as a covering material on the lower surface of the aluminum alloy rolling plate constituting the outer surface of the case of the small electronic device through a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive.

The thus obtained aluminum alloy rolled laminated plate was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width and 4.5 mm in corner portions to prepare the molding material of Example 4.

<Comparative Example 1>

0.4 to 1.0 mass% of Si, 0.4 to 1.0 mass% of Mn, 4.0 to 4.9 mass% of Mg, 0.4 mass% or less of Fe, 0.05 to 0.25 mass% of Cr and 0.25 mass% or less of Zn, And an aluminum alloy extruded plate made of an aluminum alloy consisting of inevitable impurities and having a 0.2% proof stress of 230 MPa and a breaking elongation of 14% and a thickness of 2 mm. The plate material is extrusion-molded, and does not have a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

A nylon resin film having a thickness of 90 mu m was laminated on both upper and lower surfaces of the aluminum alloy extruded plate through a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive. The aluminum alloy extruded laminated sheet thus obtained was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width and 4.5 mm in corner portions to produce a molding material of Comparative Example 1. [

<Comparative Example 2>

Wherein the alloy includes at least one of Si: 0.4 mass% or less, Mg: 2.1 to 2.9 mass%, Fe: 0.5 mass% or less, Cu: 1.2 to 2.0 mass%, Mn: 0.3 mass% or less, Cr: 0.18 to 0.28 mass% And an aluminum alloy extruded plate made of an aluminum alloy containing Al and unavoidable impurities and having a 0.2% proof stress of 510 MPa and a breaking elongation of 11% and a thickness of 1.5 mm. The plate material is extrusion-molded, and does not have a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

Then, this aluminum alloy extruded plate was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width, and 4.5 mm in corner portions to produce a molding material of Comparative Example 2. [

<Comparative Example 3>

Wherein the aluminum alloy ingot is composed of 0.2 to 0.6 mass% of Si, 0.45 to 0.9 mass% of Mg, 0.35 mass% or less of Fe, 0.1 mass% or less of Cr and 0.1 mass% or less of Zn, Was homogenized at 580 占 폚 for 10 hours, then spun, pre-heated to 500 占 폚, and hot-rolled was started. The final pass starting temperature of hot rolling was set at 400 캜, and after passing, it was cooled at a rate of 80 캜 / min. Thereafter, heat treatment was performed at 240 DEG C for 4 hours. Thereafter, cold rolling was performed at a reduction ratio of 57%, and then heat treatment was performed at 250 DEG C for 2 hours. Thus, an aluminum alloy rolled plate having a 0.2% proof stress of 150 MPa and a 3 mm thickness with an elongation at break of 14% was obtained. The plate material is obtained by natural aging treatment after cold rolling, and does not have a fibrous crystal structure extending in the direction perpendicular to the thickness direction.

Then, a nylon resin film having a thickness of 30 mu m was laminated on both upper and lower surfaces of the aluminum alloy rolled plate through a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive.

The thus obtained aluminum alloy rolled laminated sheet material was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width and 4.5 mm in corner portions to produce a molding material of Comparative Example 3.

<Comparative Example 4>

0.2 to 0.6 mass% of Si, 0.45 to 0.9 mass% of Mg, 0.35 mass% or less of Fe, 0.1 mass% or less of Cr and 0.1 mass% or less of Zn, with the balance being Al and inevitable impurities An aluminum alloy rolled plate having a thickness of 2 mm with 0.2% proof stress of 145 MPa and elongation at break of 12% was prepared. The plate material is cold-rolled (reduction rate: 33%) of the extruded plate material and does not have a fibrous crystal structure extending in the direction orthogonal to the thickness direction.

Then, a nylon resin film having a thickness of 30 mu m was laminated on both upper and lower surfaces of the aluminum alloy rolled plate through a pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive.

The aluminum alloy rolled laminated sheet material thus obtained was cut into a roughly rectangular shape of 150 mm in length, 82 mm in width and 4.5 mm in corner portions to prepare a molding material of Comparative Example 4. [

<Molding of a small electronic device case>

The molding materials of Examples 1 to 4 and Comparative Examples 1 to 4 were drawn by using a drawing processing apparatus shown in Fig. 2 to obtain a molded article having a length of 140.5 mm, a width of 70.5 mm, a side wall height (molding height) of 7 mm, A case of a small electronic device having a corner portion of 2 mm was molded. The angle of the sidewall with respect to the bottom wall was 90 [deg.].

Each of the formed cases was visually observed. As for the ones made of the molding materials of Examples 1 to 4, wrinkles and cracks did not occur in the corner portions of the side walls, and the outer surface of the side walls had scratches It was not shown.

On the other hand, with respect to the case made of the molding material of Comparative Examples 1 to 4, wrinkles and cracks are formed in the corner portions of the side walls. In the case of the case made of the molding materials of Comparative Examples 1, 3 and 4, scratches were not observed on the outer surface of the side wall, but scratches due to contact with the lower mold were formed on the outer surface of the side wall of the case of Comparative Example 2 .

INDUSTRIAL APPLICABILITY The present invention can be suitably used for molding a case of a small electronic device such as a tablet terminal, a portable communication terminal device, a notebook type personal computer, a portable telephone, a portable music device, and a digital camera.

(1): Aluminum alloy rolled laminated sheet material
(2): Aluminum alloy rolled sheet
(3) (4): Cover material
(30) (40): a synthetic resin film
(31) (41): Metal foil
(32) (33) (42) (43): synthetic resin film
(5): Fixed type
(6): movable type
(20): Small electronic case
(21): bottom wall
(22): side wall
(22a): corner portion

Claims (13)

An aluminum alloy rolled laminated sheet for forming a case of a small electronic device by drawing processing, comprising: an aluminum alloy rolled plate having a 0.2% proof stress of 200 MPa or more; and a cover material laminated on at least one of both surfaces of the aluminum alloy rolled plate And the cover material is made of either one of a synthetic resin film and a laminate in which a synthetic resin film is laminated on both surfaces of a metal foil. The method according to claim 1,
An aluminum alloy rolled laminated sheet for a small electronic device case, characterized in that the aluminum alloy rolled plate has a fibrous crystal structure stretched in a direction orthogonal to the thickness direction. The method according to claim 1,
Wherein the aluminum alloy rolled plate comprises an Al-Mn-Mg based alloy containing 0.2 to 0.7% by mass of Mn, 2.0 to 5.0% by mass of Mg and the balance Al and inevitable impurities, 0.2 to 0.8% by mass of Si, An Al-Si-Mg-based alloy containing 0.4 to 1.2% by mass of Al and an inevitable impurity as a remainder, 4.0 to 6.5% by mass of Zn and 0.5 to 3.0% by mass of Mg, And the Al-Zn-Mg-based alloy is made of an aluminum alloy. 3. The method of claim 2,
Wherein the aluminum alloy rolled plate comprises an Al-Mn-Mg based alloy containing 0.2 to 0.7% by mass of Mn, 2.0 to 5.0% by mass of Mg and the balance Al and inevitable impurities, 0.2 to 0.8% by mass of Si, An Al-Si-Mg-based alloy containing 0.4 to 1.2% by mass of Al and an inevitable impurity as a remainder; 4.0 to 6.5% by mass of Zn and 0.5 to 3.0% by mass of Mg; And the Al-Zn-Mg-based alloy is made of an aluminum alloy. The method according to claim 1,
Characterized in that the thickness of the covering material is 0.05 to 1.5 times the thickness of the aluminum alloy rolled plate material. The method according to claim 1,
Wherein the thickness of the aluminum alloy rolled plate is 0.5 to 3.5 mm. The method according to claim 1,
Characterized in that a cover material made of a polyester resin film or a polyamide resin film having a thickness of 50 to 100 占 퐉 is laminated on the surface of the aluminum alloy rolled plate which is the outer surface of the small electronic equipment case on both sides of the aluminum alloy rolled plate, Rolled laminated sheet. 5. The method of claim 4,
Characterized in that a cover material made of a polyester resin film or a polyamide resin film having a thickness of 50 to 100 占 퐉 is laminated on the surface of the aluminum alloy rolled plate which is the outer surface of the small electronic equipment case on both sides of the aluminum alloy rolled plate, Rolled laminated sheet. The method according to claim 1,
Characterized in that a cover material made of a polyethylene resin film, a polypropylene resin film or a polyamide resin film having a thickness of 10 to 100 占 퐉 is laminated on the inner surface side of a small electronic equipment case on both sides of an aluminum alloy rolled plate material. Aluminum alloy rolled laminated sheet for instrument case. Characterized in that the aluminum alloy rolled laminated sheet material for a small electronic device case according to any one of claims 1 to 9 is drawn and covered with at least one of the inner and outer surfaces of both sides thereof with a covering material comprising a synthetic resin film or a laminate A small electronic case with a covering material. A method for manufacturing a compact electronic device, comprising the steps of: drawing an aluminum alloy rolled laminated plate for a case of a small electronic device according to any one of claims 1 to 9 and then removing the covering material covering at least one of the inner and outer surfaces; Device case. 12. The method of claim 11,
A bottom wall and side walls erected at the periphery of the bottom wall, the height of the side wall being 0.5 to 25 mm, and the angle of the side wall to the bottom wall being 90 to 150 degrees. A method of forming a case of a compact electronic device characterized by drawing an aluminum alloy rolled laminated plate for a case of a small electronic device according to any one of claims 1 to 9.

Images