JPH0793512B2 - Electromagnetic wave shielding metal thin film laminated sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electromagnetic wave shielding metal thin film laminated sheet. More specifically, the present invention relates to a metal thin film laminated sheet which has a surface which is soft and has appropriate compression elasticity and which has an excellent electromagnetic wave shielding property.

[Conventional technology]

With the recent development and popularization of electronic devices, it is necessary to protect these devices and magnetic recording bodies from the adverse effects of static electricity and electromagnetic waves. As this protective material, a sheet material, for example, a covering sheet material. And the demand for packaging sheet materials is increasing.

In order to protect electronic devices from the influence of static electricity, a conductive sheet containing carbon powder, carbon fiber, metal foil, or a conductive material containing metal powder has been used. However, such a conventional conductive sheet cannot be said to be sufficiently effective for the purpose of protecting electronic devices from the influence of electromagnetic waves, and its deformation (flexibility) is insufficient, It was difficult to fit the shape of the equipment to be protected.

Further, a laminated sheet in which a film is attached to a metal thin film having an electromagnetic wave shielding property has been developed, but a conventional metal thin film laminated sheet has a hard surface and poor elasticity, and therefore,
Even if this laminated sheet is used for covering and packaging of electronic devices, it does not fit these devices, and the drape property and cushioning property are also insufficient, and furthermore, the metal thin film is easily broken by bending or bending, There are problems such as remaining folds, peeling of the laminated component layers from each other, partial whitening, and uneven streaks.

[Problems to be Solved by the Invention]

The present invention has problems of the conventional electromagnetic wave shielding metal thin film laminated sheet, that is, lack of flexibility and elasticity of the surface,
The metal thin film is torn or broken due to the bending that occurs,
It also solves problems such as creases, formation of creases, whitening due to peeling of component layer bending, and generation of streaks, and flexible adaptability to shape deformation, good drape, good surface flexibility and It is intended to provide an electromagnetic wave shielding metal thin film laminated sheet which has a compressive elasticity and an excellent shielding property against both an electric field and a magnetic field and is useful for equipment packaging.

[Means and Actions for Solving the Problems]

MEANS TO SOLVE THE PROBLEM The electromagnetic wave shielding metal thin film laminated sheet of the present invention is capable of solving the above-mentioned problems and comprises an electromagnetic wave shielding metal thin film layer and a flexible sheet material bound on at least one surface thereof. A plurality of conductive metal platings each including one or more coating layers, the metal thin film layer including a ribbon-shaped thin film substrate made of amorphous metal and a conductive metal plating layer coating at least one surface thereof. It is formed by arranging amorphous metal thin film ribbons in parallel to each other, wherein the coating layer is at least one flexible polymer foam porous sheet material layer, and the flexible polymer foam porous material. A reinforcing layer which is bound to the sheet material layer and is made of a fiber cloth.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, a flexible sheet material in which at least one coating layer is formed by binding a coating layer made of a flexible sheet material on both surfaces of the metal thin film layer is applicable. It may include a flexible polymer foam porous sheet material.

Further, in the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the coating layer bound on one surface of the metal thin film layer includes a flexible polymer foam porous sheet material layer, and The coating layer bound on the other side may include a layer of flexible polymeric non-porous sheet material.

The metal thin film used for the electromagnetic wave shielding metal thin film laminated sheet of the present invention is composed of an amorphous metal thin film.

Recently, attempts have been made to use amorphous metals for various applications based on their properties. Amorphous metal thin films are generally supplied as ribbon-shaped materials with a width of 2.54 to 10.16 cm.
20.32 cm narrow sheet is expected to be supplied.

Conventionally, the ribbon-shaped or small (narrow) width material as described above can be used only as a card case or a packaging material for small items, and a covering sheet requiring a wide width of 100 to 300 cm. It was thought to be almost impossible to use for such purposes.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the amorphous metal thin film is used up to its supply width, or if necessary, by bonding it to a desired width.

The above-mentioned effect of protecting the electronic device means an effect that the electromagnetic wave energy is absorbed or reflected by the electromagnetic wave shield means so that the electronic device is not affected by the electromagnetic wave energy. The degree of electromagnetic wave energy attenuation by the electromagnetic wave shield means is expressed in a unit decibel (dB), and as the electromagnetic wave shield material has a larger value, the attenuation effect is larger, which is preferable.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the electromagnetic wave shielding effect is substantially dependent on the shielding effect of the amorphous metal thin film contained therein, and is generally preferably 10 dB or more, and 30 dB or more. More preferably, it is more preferably 60 dB or more, still more preferably 90 dB or more. In the electromagnetic shielding metal thin film laminated sheet of the present invention, the amorphous metal used is generally iron as a main component, and boron, silicon, carbon, nickel, cobalt,
It is preferably selected from amorphous alloys obtained by adding one or more selected from molybdenum and the like. For example, Allied's product name METGLAS No. 2605SC (F
e: 81%, B: 13.5%, Si: 3.5%, C: 2% amorphous alloy), No. 2605S-C (Fe: 78%, B: 13%, Si: 9% amorphous alloy), No .2605-CO (Fe: 87 parts, B: 14 parts, Si: 1
Part, Co: 18 parts amorphous alloy), No. 2826-MB (Fe: 4
0%, Ni: 38%, Mo: 4%, B: 18% amorphous alloy) and the like can be used.

In addition to the above-mentioned iron-based alloy system, cobalt-based alloy system (for example, Co ₉₀ Zr ₁₀ , Co ₇₈ Si ₁₀ B ₁₂ , C
o ₅₆ Cr ₂₆ C ₁₈ ,, Co ₄₄ Mo ₃₆ C ₂₀ ,, Co ₃₄ Cr ₂₈ Mo ₂₀ C ₁₈ ), an alloy system containing nickel as the main component (for example, Ni ₉₀ Zr ₁₀ , Ni ₇₈ Si ₁₀ B ₁₂ , N)
i ₃₄ Cr ₂₄ Mo ₂₄ C ₁₈ ) and alloys based on other metals (eg Pd ₈₀ Si ₂₀ , Cu ₈₀ Zr ₂₀ , Nb ₅₀ Ni ₅₀ , Ti ₅₀ C
u ₅₀ ) etc. are also available.

Further, the amorphous metal thin film may be a perforated thin film as long as it does not substantially affect the electromagnetic wave shielding property.

Since these amorphous metal thin film materials are often supplied in the form of ribbons or narrow sheets as described above, when they are used in the electromagnetic wave shielding metal thin film laminated sheet of the present invention, if necessary. A plurality of ribbon-shaped or narrow sheet-shaped amorphous metal thin film materials are arranged in parallel with each other to form a wide sheet-shaped body, and if necessary, their opposite side edges are joined by an adhesive or solder. To obtain a wide sheet body having a desired width. Also,
The amorphous metal thin film may be formed by using amorphous metal powder. Alternatively, it may be used as a knitted woven fabric-like or non-woven fabric-like sheet from thin wires made of amorphous metal, and this sheet may be used as an amorphous metal thin film.

The amorphous metal thin film as described above has an excellent shield effect against a magnetic field.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the amorphous metal thin film layer comprises a base thin film layer made of amorphous metal and a conductive metal plating layer covering at least one surface thereof. As the conductive metal for plating, for example, copper, nickel, cobalt, iron, aluminum, gold, silver, tin, zinc, and an alloy of two or more selected from these can be used. In this way, when a conductive metal is plated on at least one surface of a substrate made of an amorphous metal thin film, the obtained amorphous metal thin film layer has the magnetic field shielding property and the electric field shielding property of the plating layer added, and the amorphous metal thin film is obtained. The entire layer can exhibit an excellent shielding effect against a wide range of electromagnetic waves from low frequencies to high frequencies.
Further, the conductive metal plating layer also has an effect of improving the solder bondability of the amorphous metal thin film.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the amorphous metal thin film layer preferably has a thickness of 100 μm or less, more preferably 1 to 70 μm, and further preferably 5 to 50 μm. It is even more preferred that it has a thickness of 10 to 30 μm.

The conductive metal plating layer contained in the amorphous metal thin film layer preferably has a thickness of 0.1 μm or more, more preferably about 0.1 to 5 μm.

When the thickness of the amorphous metal thin film layer is more than 100 μm, the rigidity of the core layer becomes excessive, the core layer is hard to be deformed, the drape property becomes insufficient, and a sharp cut surface may be formed, which may be dangerous in operation. In addition, a thin protective film such as a rust preventive may be formed on the surface of the amorphous metal thin film layer or the metal plating layer thereof.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, at least one surface of the amorphous metal thin film layer includes a foamed porous sheet material layer of a flexible polymer and a reinforcing layer which is bound to the foamed porous sheet material layer and is made of a fiber cloth. The coating layer is bound. The electromagnetic wave shielding metal thin film laminated sheet covered with the covering layer including the foamed porous sheet material layer and the fiber cloth reinforcing layer exhibits favorable flexibility, compression elasticity, and shock-proof and pressure-damping property.

That is, when an external force such as bending acts on the electromagnetic wave shielding metal thin film laminated sheet, the foamed porous sheet material layer and the fiber cloth reinforcing layer deform and absorb the external force, and the expansion and compression of the amorphous metal thin film are reduced. However, this exerts a buffering effect of preventing the amorphous metal thin film from breaking or breaking and preventing permanent deformation (crease formation). Such an electromagnetic wave shielding metal thin film laminated sheet is useful as a sheet for covering electronic equipment or a sheet for packaging and storing.

Suitable flexible polymeric materials for forming the foamed porous sheet material include natural rubber, synthetic rubber (such as SBR, NBR, nitrile rubber, polychloroprene rubber, polyisobutylene rubber, fluorine-containing rubber, and silicone rubber). These are often used in the latex state), and flexible synthetic resins (eg, polyethylene, polyurethane, polyvinyl chloride, and polystyrene),
It can be arbitrarily selected. The foamed porous sheet material may be a rigid foam as long as it is flexible, but it is generally preferred that it is a flexible foam.

The porosity of the foamed porous sheet material layer is preferably 50 to 99% (foaming ratio: 2 to 100 times), and more preferably 80 to 98% (foaming ratio: 5 to 50 times). Usually, a foaming ratio of 20 to 60 times is used. The compression resistance of the foamed porous sheet material layer is 10 kg / cm ^{2 at} 25% compression.
It is practically possible depending on the application if it is below, but generally 0.
It is preferably 5 kg / cm ² or less, and more preferably 0.1 kg / cm ² or less.

The thickness of the foamed porous sheet material layer is not particularly limited and can be arbitrarily set according to the application of the electromagnetic wave shielding metal thin film laminated sheet, but generally 0.5 to 100 mm.
Is preferably within the range of 1, and more preferably within the range of 1 to 50 mm.

When the foamed porous sheet layer of the coating layer is bound to the amorphous metal thin film layer, a foamed porous sheet may be prepared in advance and bound with an adhesive, or The adhesive surface portion of the foamed porous sheet material layer may be heat-melted and fused. The foamed porous sheet material layer may be formed by chemically foaming on an amorphous metal thin film, or a polymer coating containing bubbles is applied on the amorphous metal thin film and solidified, You may form by what is called a mechanical foaming method.

The coating layer including the flexible polymer foam porous sheet material layer as described above may be formed on both sides of the amorphous metal thin film, or may be formed on only one side thereof. In the latter case, a coating layer including a non-porous sheet material layer of the flexible polymer as described above may be bonded to the other surface of the amorphous metal thin film layer.

The flexible polymer foam porous sheet material layer and optionally the non-porous sheet material layer described above are laminated and bound with a reinforcing layer made of a fiber cloth to form a coating layer. The electromagnetic wave shielding metal thin film laminated sheet of the present invention having such a fiber cloth reinforcing layer is used for applications requiring high mechanical strength,
For example, it is useful as a heavy packaging material or a heavy coating material.

The tear strength of the amorphous metal thin film is so low that it is almost equal to 0, and it tears easily at a low load. Also, such an amorphous metal thin film is relatively weak in tensile strength,
Moreover, there is a large variation in strength. For example, the tensile strength of a 25 μm-thick amorphous metal thin film can be determined by JIS-L-1096 (1
979). In accordance with 6.12 of "General woven fabric test method", tensile strength and elongation rate 6.12.1 (1) A method, (strip method),
Width: 3 cm, gripping interval: 20 cm, pulling speed: 200 mm / min, the tensile strength is 65-125 kg / 3c
m, an average of about 100 kg / 3 cm, which is relatively weak, and the measured values vary widely.Amorphous metal thin films are generally provided in the shape of a narrow ribbon. If formed into a sheet, even if they are adhered at their opposite side edges by soldering or a bonding agent, the tensile strength in the lateral direction of the sheet is insufficient, and There is a problem that the variation is large. Therefore, for heavy packaging, electromagnetic wave shielding metal thin film laminated sheet used for heavy coating, or locally rubbed, electromagnetic wave shielding metal thin film laminated sheet used for the application of external force locally, It is effective to be reinforced by the fiber fabric reinforcing layer.

The tensile strength of the fiber cloth of the fiber cloth reinforcing layer is preferably higher than the tensile strength of the amorphous metal thin film layer. Such a fiber cloth reinforcing layer can reinforce the tensile strength of the amorphous metal thin film layer and reduce variations in the tensile strength.

Further, when a fiber having a breaking elongation of 5% or less is used as the reinforcing layer fiber cloth, the difference in extensibility between the core layer and the fiber cloth reinforcing layer becomes small. Therefore, the SS load curves of both are approximate. ,
Therefore, the base layer can exhibit a relatively large tensile strength. Further, if the breaking elongation is equal to that of the amorphous metal thin film, or if a fiber cloth of 5% or less is combined with the core layer as a reinforcing layer, only the amorphous metal ribbons need to be arranged in parallel to form the core layer. It is not always necessary to bond the ribbon with solder or with a bonding agent. An amorphous metal thin film without such a joint is
The seams are inconspicuous and show a good appearance.

130 kg / mm ² as the fibers that make up such fiber cloth
A material having the above tensile strength and a breaking elongation of 5% or less is preferable. There is no particular limitation on the type of fiber having such performance, but the following are exemplified.

These high-strength fibers are effective in achieving the above effects, but have low elongation and low flexural strength. Therefore, when high flex resistance is required for the application of the electromagnetic wave shielding metal thin film laminated sheet, it is preferable to mix other fibers having high elongation and high flex strength with the high strength fiber. There is no particular limitation on the kind of the high elongation fiber, but examples thereof are as follows.

The surface of the fiber fabric reinforcing layer may have required smoothness, or slip resistance, or a desired color or pattern, depending on the application of the electromagnetic wave shielding metal thin film laminated sheet, The fiber cloth reinforcing layer may be subjected to a treatment for imparting the above-mentioned characteristics, or a coating may be applied thereto.

In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the amorphous metal thin film layer is covered with at least one foam porous layer sheet material layer and a fiber cloth reinforcing layer, and the foam porous sheet material layer and fiber cloth reinforcing layer. The layers are deformable and compressible. Therefore,
For example, when this electromagnetic wave shielding metal thin film laminated sheet is bent and deformed, the foamed porous sheet material layer and the fiber cloth reinforcing layer are easily deformed to prevent expansion and breakage of the amorphous metal thin film, and easily compressed. Transform,
It can fit into the shape of the device to be (heavy) coated or (heavy) packaged.

The electromagnetic wave shielding metal thin film laminated sheet of the present invention will be further described below with reference to examples.

Example 1 Amorphous alloy thin film (Fe: 81%, B: 13.5%, Si: 3.5%, C:
2%, trademark: METGLAS No.2605SC, Allied, width 7.62c
m, 25 μm thick ribbon-like body), 1 μm thick on all surfaces
Copper plated.

Thirteen pieces of the copper-plated amorphous alloy thin film ribbons were arranged in parallel with each other, and the side edges of the ribbons were overlapped by 1 cm, and formed into a sheet having a width of about 85 cm without adhering.

A synthetic rubber adhesive (trademark: SC 12N, manufactured by Sony Chemical Co., Ltd.) is applied to one side of this wide amorphous alloy sheet-like material, and a glass cloth of a ginseng type (trademark: K
S-5207, manufactured by Kanebo Glass Fiber Co., Ltd., thickness 0.1 mm, basis weight 38 g /
m ² , entangled weave, diameter (7 + 7) /25.4mm, weft 7 / 25.4m
m, fiber tensile strength 350 kg / mm ² , fiber breaking elongation 3%, cloth tensile strength, both longitudinal and latitudinal directions 18,20 kg / 2.5 cm, cloth breaking elongation and longitudinal and lateral directions 3.0%) The above adhesive was applied on the above, and a polyurethane foam having a foaming ratio of 40 times (porosity: 97.5%) and a thickness of 5 mm was attached to the applied surface to form a packaging material.

The obtained electromagnetic wave shielding metal thin film laminate sheet is 50 dB
The electromagnetic wave shielding property of Further, in this electromagnetic wave shielding metal thin film laminated sheet, the elongation deformation of the glass fiber gauze is extremely small, so that there is no slide or slip of the amorphous metal thin film ribbon, and the swelling of the overlapping part is hardly noticeable. Was there.

This electromagnetic wave shielding metal thin film laminated sheet exhibited good tensile strength and tear strength and was easy to handle.

Example 2 The same operation as in Example 1 was performed. However, 11 copper-plated amorphous alloy thin film ribbons were arranged in parallel, and the side edges of the ribbons were soldered together to form a wide sheet having a width of about 80 cm.

The obtained electromagnetic wave shielding metal thin film laminated sheet,
It showed an excellent electromagnetic wave shielding effect of 50 dB.

Comparative Example 1 A stainless steel metal thin film ribbon having a thickness of 4.9 μm and a width of 10 cm was copper-plated with a thickness of 1 μm on the entire surface.

This copper plated stainless steel metal film ribbon
Width of about 105c
I made a wide sheet of m.

A synthetic rubber adhesive (trademark: SC 12N, made by Sony Chemical Co., Ltd.) was applied to one side of this wide stainless steel sheet, and the expansion ratio was 40 times (porosity: 97.5%) and thickness was 5 mm on that side.
The polyurethane foam of No. 1 was attached to make a packaging material. This one had an electromagnetic wave shielding property of 35 dB.

〔The invention's effect〕

The electromagnetic wave shielding metal thin film laminated sheet of the present invention shows good electromagnetic wave shielding property due to the plated amorphous metal thin film layer, and includes a coating layer including a flexible polymer foam porous sheet material layer and a fiber cloth reinforcing layer. Good flexibility, compression resilience and accompanying cushioning were obtained by laminating it on the amorphous metal thin film layer. In the electromagnetic wave shielding metal thin film laminated sheet of the present invention, the foamed porous sheet material layer is compressed and depressed during bending, and the amorphous metal thin film layer is bent with a large curvature. The amorphous metal thin film will not be abnormally stretched and broken or broken due to the buffering action of the above, or will not be bent due to the buffering action of the elastic body to cause creases, and the (heavy) coated sheet Or as a (heavy) packaging sheet.

Claims (16)

[Claims] 1. An electromagnetic wave shielding metal thin film layer and one or more coating layers made of a flexible sheet material and bound on at least one surface thereof, wherein the metal thin film layer is made of an amorphous metal. And a plurality of conductive metal-plated amorphous metal thin film ribbons each comprising a ribbon-shaped thin film substrate and a conductive metal plating layer covering at least one surface thereof are arranged in parallel with each other, The coating layer includes at least one flexible polymer foam porous sheet material layer, and a reinforcing layer which is bonded to the flexible polymer foam porous sheet material layer and is made of a fiber cloth. An electromagnetic wave shielding metal thin film laminated sheet characterized by the above. 2. A coating layer made of a flexible sheet material is attached to both surfaces of the metal thin film layer, and at least one of the coating layers is bonded.
The electromagnetic shielding metal thin film laminate sheet according to claim 1, wherein the flexible sheet material forming the layer comprises a flexible polymer foam porous sheet material layer. 3. A coating layer bound on one side of said metal thin film layer comprises a flexible polymer foam porous sheet material layer, and bound on another side of said metal thin film layer. An electromagnetic wave shielding metal thin film laminate sheet according to claim 2, wherein the coated layer comprises a non-porous sheet material layer of a flexible polymer. 4. A coating layer comprising the flexible polymeric non-porous sheet material layer is bound to the non-porous sheet material layer,
The electromagnetic wave shielding metal thin film laminated sheet according to claim 3, which has a reinforcing layer made of a fiber cloth. 5. The metal thin film layer according to claim 1, wherein the plurality of amorphous metal thin film ribbons arranged in parallel are bonded to each other at their side edge portions that are adjacent to each other and facing each other. The electromagnetic wave shielding metal thin film laminated sheet described. 6. The electromagnetic wave shielding metal thin film laminated sheet according to claim 5, wherein the amorphous metal thin film ribbon is joined by soldering. 7. The method according to claim 5, wherein the amorphous metal thin film ribbon is joined by a conductive adhesive.
An electromagnetic wave shielding metal thin film laminated sheet according to the item. 8. The electromagnetic wave shielding metal thin film laminated sheet according to claim 1, wherein the amorphous metal thin film has a thickness of 100 μm or less. 9. The electromagnetic wave shielding metal thin film laminated sheet according to claim 8, wherein the amorphous metal thin film has a thickness of 70 μm or less. 10. The electromagnetic wave shielding metal thin film laminated sheet according to claim 1, wherein the conductive metal plating layer on the amorphous metal substrate thin film has a thickness of 0.1 μm or more. 11. The amorphous metal mainly composed of Fe, to which at least one selected from B, Si, C, Co, Ni and Mo is added, and the amorphous metal is an amorphous metal. An electromagnetic wave shielding metal thin film laminated sheet according to the item. 12. The electromagnetic wave shielding metal thin film laminate sheet according to claim 1, wherein the coating layer having the flexible polymer foam porous sheet material layer has a thickness of 0.5 to 100 mm. 13. The flexible polymer foam porous material layer comprises 55
The electromagnetic wave shielding metal thin film laminated sheet according to claim 1, which has a porosity of ˜99%. 14. The fiber fabric reinforcement layer has a higher tensile strength than the metal thin film layer.
An electromagnetic wave shielding metal thin film laminated sheet according to the item. 15. The electromagnetic wave shielding metal thin film laminated sheet according to claim 1, wherein the fiber fabric reinforcing layer has a breaking elongation of 5% or less. 16. The electromagnetic wave shielding metal according to claim 1, wherein the fiber cloth reinforcing layer contains fibers having a tensile strength of 130 kg / mm ² or more and a breaking elongation of 5% or less. Thin film laminated sheet.