JPS6382000A - Electromagnetic shielding wall cladding material and method of its application - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic wave shielding wall covering material and a method for forming this wall covering material on a wall surface.

More specifically, the present invention provides a wall covering material that has excellent shielding properties against electromagnetic waves and has a sufficiently beautiful appearance and durability for practical use, and a method for forming this wall covering material on a wall surface. It is about the method.

[Conventional technology]

In recent years, with the development and spread of electronic devices, there has been a need for wall covering materials that can protect these devices from the negative effects of static electricity and/or electromagnetic waves, and that have a beautiful appearance and durability sufficient for practical use. It's here. Conventionally, conductive materials containing carbon powder or fibers, or conductive materials containing metal foil or powder have been used to protect electronic devices from static electricity; Materials cannot be said to be effective enough to comprehensively and simultaneously protect various and multiple electronic devices from NMi waves, and as wall covering materials, their appearance , and durability could not be said to be fully satisfactory.

Therefore, attempts have been made to form a so-called shield room in which the entire room housing electronic equipment is shielded from electromagnetic waves, and efforts are being made to put it into practical use.

However, a wall covering material and a method for forming the same that can sufficiently respond to such attempts have not yet been provided.

[Problem that the invention seeks to solve]

The present invention utilizes various metal thin films to provide a wall that has sufficient shielding and protective effects against both static electricity and electromagnetic waves, satisfies appearance requirements, and has sufficient durability for practical use. The object of the present invention is to provide a wall covering material and a method for easily forming such a wall covering material on a wall surface in accordance with various requirements.

[Means and effects for solving the problems] The electromagnetic wave shielding wall covering material of the present invention includes a core layer containing a metal thin film and a wallpaper layer covering one side of the core layer.

The method of the present invention for forming the above-mentioned electromagnetic shielding wall covering material on a wall surface includes adhering a core layer containing a metal thin film to the wall base surface,
This involves pasting a wallpaper sheet onto this core layer.

The wall covering material of the present invention includes a core layer containing a metal thin film and a wallpaper layer as described above.

The metal thin film contained in the core layer is amorphous (non-crystalline)
It may be formed from a metal or a non-amorphous (including crystalline) metal. Many of these amorphous or non-amorphous metal thin films are magnetic and can exhibit excellent electromagnetic shielding properties against magnetic fields. If particularly high magnetic field shielding properties are required, it is preferable to use an amorphous metal thin film.

Recently, attempts have been made to utilize amorphous metals for inoculation purposes based on their properties. Generally, amorphous metal is supplied as a ribbon-shaped material with a width of 2.54 to 10.16 C11, and it is expected that a material with a width of 20.320 C11 will be supplied in the near future. It was thought that it would be almost impossible to use small and medium-sized materials as covering sheet materials.

In the present invention, the amorphous metal material is used in the form of a sheet having a desired width.

Recently, attempts have been made to utilize non-amorphous metal thin films (foils) for various purposes based on their properties. Generally, non-amorphous metal thin films have a width of 70 cm or less, and most of them are supplied as a narrow material with a width of 5 to 60 cm. Recently, as an exception, rolled iron foil with a width of 960 mm and electrolytic iron foil with a width of 120 CIm have been supplied.
Its supply is small.

In addition, non-amorphous metal thin films (foils) generally available on the market
The thickness is approximately 50 μm to 20 μm.

Conventionally, it was thought that it was almost impossible to use the above-mentioned ribbon-like or small (narrow) width materials for covering sheets that require a wide width of 100 to 300 cm.

In the present invention, the non-amorphous metal material is used in the form of a sheet of desired width.

In the wall covering material of the present invention, the metal thin film-containing core layer may be formed from a metal thin film alone, or may be formed from a metal thin film and a conductive metal plating layer covering at least one surface of the metal thin film. It may be something. As the conductive metal, for example, copper, nickel, cobalt, iron, aluminum, gold, silver, tin, zinc, and alloys of two or more selected from these can be used.

When a conductive metal is plated on at least one surface of the metal thin film, the resulting core layer has the electric field shielding property of the plating layer added to the magnetic field shielding property of the metal thin film, and the core layer as a whole has a high frequency range from low frequency to high frequency. It can exhibit excellent shielding effects against a wide range of electromagnetic waves.

Furthermore, the conductive metal plating layer also has the effect of improving the solder adhesion of the metal thin film.

Regarding the type of amorphous metal used for the metal thin film in the present invention, it is difficult to prevent static electricity and electromagnetic waves.
There are no particular limitations and materials can be selected from commercially available materials as long as they have the effect of protecting electronic equipment, but generally iron is the main component, along with boron, silicon, carbon, nickel, cobalt, and molybdenum. For example, Allied's trade name METGLAS 1t2605sc (Fe:
8 I%, B: 13.5%, Si: 3.5%, C: 2
% amorphous alloy), k2605s-2 (Fe
: 78%, B: 13%.

Si: 9% amorphous alloy), -2605-C0 (
Amorphous alloy of Fe: 87 parts, B: 14 parts, 5 μm 1 part, Co: 18 parts), Na2826 MB (F
An amorphous alloy of e: 40%, Ni: 38%, Mo: 4%, B: 1B%, etc. can be used.

Further, the amorphous metal thin film may be formed using amorphous metal powder, or may be formed from fine wires made of amorphous metal into a woven fabric or non-woven fabric sheet and used as the amorphous metal sheet. .

The amorphous metal described above is a magnetic material and has an excellent shielding effect against magnetic fields.

In the present invention, the type of non-amorphous metal used for the metal thin film is not particularly limited as long as it has the effect of protecting electronic equipment from static electricity and electromagnetic waves, and may be selected from commercially available materials. Can be done.

The general commercially available non-amorphous metal thin film materials mentioned above include:
Titanium, beryllium-copper, stainless steel and other widths 6c! ultra-thin metal foil with a thickness of 1.4 μm to 4°9 μm, titanium, beryllium copper, copper alloy (phosphor bronze, brass, bronze), nickel silver, aluminum alloy, stainless steel, nickel, permalloy, nickel. chromium alloy,
Niobium, 4270I, palladium, tantalum, tin, lead,
Zinc, iron, gold, silver, silver alloy, platinum, and other widths 10 (J
General metal foil with a thickness of 5 to 200 μm, titanium, beryllium copper, nickel, gold, silver, platinum, palladium, aluminum, red copper, silver alloy, and other widths of 3 to 4 (about J, thickness of 0.3 to Ultra-thin foil of about 1.0 μm, titanium, copper and copper alloys (beryllium copper, red copper, phosphor bronze, brass, Inconel, Constantun), nickel and nickel alloys,
Aluminum and aluminum alloys, niobium, tantalum, iron, stainless steel, gold, silver, platinum, palladium, rare metal alloys, zinc, lead, tin, etc. Width about 51, thickness 1.0 to 1
．． It can be selected from ultra-thin foils of 5 μm and other thin metal films (foils).

Further, the metal thin film may be a perforated thin film within a range that does not substantially affect its electromagnetic shielding properties.

The above-mentioned protection effect for electronic equipment refers to the effect of absorbing or reflecting electromagnetic energy by the electromagnetic wave shielding means to prevent the influence of electromagnetic energy from reaching the electronic equipment. The degree of electromagnetic wave energy attenuation by this electromagnetic wave shielding means is expressed in units of decibels (dB), and the larger this value is, the greater the attenuation effect is, which is preferable for the electromagnetic wave shielding material.゛In the wall covering material of the present invention, its electromagnetic shielding effect almost depends on the shielding effect of the metal thin film contained therein, and is generally preferably 10 dB or more, and 3
It is more preferably 0 dB or more, even more preferably 60 dB or more, and even more preferably 90 dB or more.

In the wall covering material of the present invention, the metal thin film-containing core layer contains 20
It is preferable to have a thickness of 0 μm or less, and 100 μm or less.
It is more preferable to have a thickness of m, even more preferably to have a thickness of 1 to 50 μm, and even more preferably to have a thickness of 5 to 30 μm. In particular, when the metal thin layer is made of amorphous metal, the amorphous metal thin film base layer preferably has a thickness of 100 μm or less, more preferably 1 to 50 μm, and 5 to 50 μm. More preferably, it has a thickness of 30 μm.

Further, the conductive metal plating layer included in the metal thin film-containing core layer preferably has a thickness of 0.1 μm or more,
It is more preferable to have a thickness of about 0.1 to 5 μm.

When the thickness of the metal thin film-containing core layer is greater than 200 μm, the core layer has excessive rigidity, is difficult to deform, has insufficient drape properties, and may form a sharp cut surface, which may pose an operational hazard. Further, a thin protective film such as a rust preventive agent may be formed on the surface of a metal thin film or a metal thin film coated with a metal.

These amorphous metals and non-amorphous metal materials are supplied in the form of ribbons or narrow sheets as described above, so in order to use them in the wall covering material of the present invention, it is necessary to prepare a plurality of ribbon-like materials. Or, by arranging small and medium-sized sheet metal thin film materials in parallel with each other and overlapping and contacting their opposing side edges, or bonding them with solder or conductive adhesive, a sheet-like material having a desired width can be formed. body.

At this time, when joining the narrow sheets, it is preferable to take measures to minimize the formation of a convex portion by the joining portion. Further, it is preferable that the protrusions are absorbed as much as possible by the wall base surface and the wallpaper layer, so that a flat wall finish surface is formed.

For this purpose, the metal thin film-containing core layer has a metal thin film (including those plated with metal) and a flexible resin coating layer covering at least one surface of the metal thin film, thereby forming a metal thin film layer. It is preferable that the surface is flattened by absorbing the unevenness of the surface.

Such flexible resins include natural rubber; neoprene rubber, chloroprene rubber, silicone rubber, Hypalon and other synthetic rubbers; and PVC resins, ethylene-vinyl acetate copolymer (EVA) resins, polyacrylic resins, silicone resins, Polyurethane resin, polyethylene (
PE) resin, polypropylene (PP) resin, polyester resin, fluorine-containing resin, and other synthetic resins can be used. The flexible resin layer made of such a material is thick enough to impart desired flatness to the resulting wall covering material, as well as desired waterproof properties, flame retardancy, mechanical strength, etc. For example, it has a thickness of 0.05 mfi or more, preferably 0.05 to 1.0 mfi.

These flexible resin layers are made of amorphous metal by using a rubber or resin film, solution, paste, or straight film as described above, and by a known method such as topping, calendering, coating, or dipping. It can be formed on the surface of the containing core layer.

These rubbers or resins contain plasticizers, stabilizers, colorants, ultraviolet absorbers, and other functional agents such as flame retardants,
A flame retardant and the like may also be included.

Conventionally, it has been known to form a resin layer with a thickness of about 1 to IQpm on the surface of metal foil for the purpose of rust prevention and corrosion prevention. The resin coating layer is generally formed to have a thickness of 30 μm or more, and this thickness is preferably 50 to 5000 μm, more preferably 100 to 3000 μm, and even more preferably 200 to 2000 μm. Therefore, the flexible resin coating layer used in the present invention is clearly different from the conventional rust-proofing and corrosion-preventing coating layer formed on metal foil. Further, the flexible resin coating layer used in the present invention can exhibit sufficient flexibility for use even if it has the above thickness,
This facilitates handling of the metal thin film-containing core layer.

The flexible resin coating layer may be formed on both sides of the metal thin film, and a wallpaper layer may be formed on one of them, or it may be formed only on one side of the metal thin film, and a wallpaper layer may be formed on one of them. The wallpaper layer may be formed on the metal thin film, or it may be formed only on one surface of the metal thin film and the wallpaper layer may be formed on the other surface.

In addition, for the purpose of flattening and reinforcing, a layer of fiber fabric having an appropriate thickness, such as a W fabric, a non-woven fabric, a compressively deformable fabric, or a composite layer thereof, is attached on at least one surface of the metal thin film. It is preferable to form a core layer containing a thin metal layer. The metal thin film-containing core layer may include both a flexible resin coating layer and a fiber fabric layer. Although there are no particular limitations on the type, thickness, and length of the fibers constituting the above-mentioned fiber fabric layer, or the structure of the fiber fabric, it is preferable that the fiber fabric has fire retardant properties and waterproof properties.

In the method of the present invention, a core layer containing a metal thin film as described above is formed on the wall base surface using an adhesive or a pressure-sensitive adhesive, if necessary. This core layer may be formed in a predetermined configuration in advance and adhered to the wall base surface, or it may be formed by sequentially laminating a predetermined configuration on the wall base surface. Good too.

When arranging two or more gold IxFf film-containing core layers in parallel and pasting them on the wall base surface, the edges of the adjacent metal thin films are exposed and they are electromagnetically bonded to each other. It is preferable to do so. For this purpose, the edges may be overlapped and brought into direct contact, or these edges may be bonded with solder or conductive adhesive or adhesive. To prevent the formation of noticeable ridges,
For example, it is preferable to take measures such as removing the resin coating layer and/or the fiber fabric layer in this area, or reducing the amount of adhesive or pressure-sensitive adhesive applied.

Before or after the operation of adhering the metal thin film-containing core layer to the surface of the wall base, a wallpaper sheet is adhered, if necessary, using an adhesive or a pressure-sensitive adhesive. Wallpaper sheets can be made in the desired composition, thickness, color,
It can be arbitrarily selected from paper, plastic sheet, or fiber cloth sheet having a pattern or the like. In particular, when raised parts are formed on a wall surface by bonding metal thin films, it is desirable to select a wallpaper sheet that has a structure, thickness, color, and pattern that makes the formation of raised parts less noticeable.

There are no particular limitations on the type of adhesive material used in the method of the present invention, including isocyanate adhesive materials, epoxy adhesive materials, polyacrylic adhesive materials, polyurethane adhesive materials, polyamide adhesive materials, rubber adhesive materials (especially synthetic rubber (type) adhesive material, etc. may be used. In addition, an amino group,
Acrylates containing imino groups, ethyleneimine residues, alkylene diamine residues, acrylates containing aziridinyl groups, amino ester-modified vinyl polymers-aromatic epoxy adhesives, amino nitrogen-containing methacrylate polymers,
are also preferred adhesive materials, but other adhesives may be used in combination.

In the wall covering material of the present invention, one or more of the adhesives used to bind each component layer may be made conductive or semiconductive, depending on its use and required performance. may be made insulating. Alternatively, different conductivities or insulating properties may be imparted to each layer and these may be combined. By doing so, products having various properties or performances can be obtained.

In the wall covering material of the present invention, the laminated finished product may be attached to the wall base surface, but according to the method of the present invention, a metal thin film-containing core layer and a wallpaper sheet are separately prepared, and these are attached to the wall base surface. It is preferable to adhere the film while sequentially laminating the film. When using a finished laminate, the finished laminate is generally wound onto a roll core and is unwound from this roll when used. In such a case, uniform bonding between the metal thin film-containing core layer and the wallpaper sheet may become insufficient, and the wallpaper sheet may be wrinkled, lifted, wavy, uneven, etc., resulting in poor finished wall surface condition.

By applying the method of the present invention to sequentially attach the core layer and the wallpaper sheet to the wall base surface, the above problems can be solved.
A flat, uniform, and beautiful wall finish can be obtained. In addition, since the core layer is made of metal thin gold, it is relatively expensive.
The method of the present invention allows the core layer and the wallpaper sheet to be stocked separately, and any combination of these can be determined according to the desired color, pattern, thickness, and material, thereby reducing the stock cost of wall covering materials. It also has the advantage of significantly reducing

〔Example〕

The laminated sheet of the present invention will be further explained by examples.

Amorphous alloy (Fe: 81%, B: 13.5
%.

Si: 3.5%, C: 2%, Trademark: METGLAS 隘2605SC.

Copper plating with a thickness of 1 μm was applied to the entire surface of a ribbon-shaped body (manufactured by Allied Co., Ltd., width 7.62C11, thickness 25 μm).

Thirteen of these copper-plated amorphous alloy ribbons were arranged in parallel and their side edges were soldered to form a wide sheet (sample (■)) with a width of about 1 m.

Synthetic rubber adhesive (trademark: SC12N, manufactured by Sony Chemical Co., Ltd.) is applied to both sides of this wide amorphous alloy sheet, and glass fiber cheesecloth (trademark: KS-52) is applied to the other side.
10, manufactured by Kanebo Glass Fiber Co., Ltd., thickness: 0.12 mm, weight: 52 g/rd, texture: leno weave, warp: (10 + 10
) book/25.4mm, latitude: 10 pieces/25.4m), and a polyvinyl chloride resin with a thickness of 0.05mm was attached to the other side of the amorphous alloy sheet I and the surface of the fiber fabric layer. The film was attached with an adhesive to form a metal thin film-containing core N (sample (■)).

The above sample CI) and the sample mark husband L are
It was attached to the entire base surface of the wall using adhesive. At this time, the edges of two or more metal thin layer-containing core layers arranged in parallel to each other expose the metal thin film over a middle 1.5 cs, and overlap each other so that the overlapping portion The resin layer and the fiber fabric layer present on the were removed.

The adhered metal thin layer-containing core layer (sample CI) and the sample (
II)) An arbitrarily selected wallpaper was pasted on top of each. At this time, the core layer and the wallpaper were arranged so that the joint of the core layer and the joint of the wallpaper did not overlap.

The walls of the obtained shielded room had a flat, uniform and beautiful appearance, and exhibited good electromagnetic shielding properties.

For comparison, we used wallpaper only without using a metal thin film, and also underlayed textile fabric and polyvinyl chloride film without a metal thin film, and then stuck wallpaper on top of that, and found that the electromagnetic wave shielding properties of the wall surface were poor. Ta.

Furthermore, a metal thin film of sample (1) and a metal thin film-containing core layer of sample (Jl) were prepared, and one side of them was pasted with polyvinyl chloride wallpaper, the other side was coated with an adhesive, and release paper was applied. The completed wall covering material laminate product obtained by stacking the layers was rolled up. This laminated finished product was spread and adhered to the base surface of a wall using a conventional method while removing the release paper.

All of the obtained wall surfaces exhibited good electromagnetic shielding properties, but curling wrinkles and curling remained, and waving was observed on the finished wall covering surface, and the appearance was slightly inferior to the above-mentioned wall surface.

Inuzashiki 2 and 3 In Example 2, copper plating with a thickness of 1 μm was applied to the entire surface of a stainless steel metal membrane ribbon with a thickness of 4.98 m and a width of IOem. The tensile strength and elongation of this ribbon are J
IS-L-1096 (1979), 6.12.1
(1) - When measured according to method A, the tensile strength was 12 to 20 kg/3 cs (average 18 kg/3 cs)
am), and the elongation at break was 0.7%.

Eleven of these copper-plated stainless steel metal film ribbons were arranged in parallel with each other, with the side edges of each
They were stacked one on top of the other and formed into a wide sheet without adhesion.

A synthetic rubber adhesive (trademark: SC12N, manufactured by Sony Chemical Co., Ltd.) is applied to both sides of this wide stainless steel sheet, and a glass fiber cloth for FRP (trademark:
KS-2671, manufactured by Kanebo Glass Fiber Co., Ltd., thickness: 0,
22m, weight: 210g/rr? , plain weave, diameter: 19
Book/25.4 dragon, Weft: 19 pieces/25.4 m, Fiber tensile strength: 350 kg/mm" Fiber breaking elongation 23%, Fabric tensile strength: 111.6 g/3 c in both weft and weft directions
ta, fabric elongation at break: 3.0% in both weft and weft directions), and a polyamide film with a thickness of 0.051 mm was pasted with an adhesive on top of this fiber fabric and on the other side of the wide stainless steel sheet. A core layer containing a metal thin film (sample (■)) was prepared.

In Example 3, a metal thin film-containing core layer (sample (IV)) was created in the same manner as in Example 2 (however, the fiber fabric sheet was not used).

Samples (III) and (TV) were each prepared in Example 1.
Similarly, it was pasted on the surface of the wall base, and wallpaper was pasted on top of it. The obtained wall surfaces all exhibited good electromagnetic shielding properties and a flat, uniform, and beautiful wall finish appearance.

〔effect〕

The metal thin film-containing wall covering material of the present invention is extremely useful for providing electromagnetic shielding properties to walls such as shielded rooms. In particular, when a plurality of wall covering materials are arranged and pasted in parallel on a large wall surface, forming the wall covering material on the wall surface using the method of the present invention facilitates electromagnetic bonding of metal thin films, and It can be completely achieved and walls of any desired color and pattern can be formed. Furthermore, by using a flexible resin coating layer and/or a fiber fabric layer in combination with the metal thin film, it is possible to reduce or absorb local protrusions on the wall surface caused by joining of the metal thin film.

In addition, the method for forming wall covering materials of the present invention enables arbitrary combinations of these materials depending on the metal thin film, so it has the advantage of avoiding dead stock and significantly reducing stock costs. be. In addition, as mentioned above, since the core layer and the wallpaper sheet are stocked separately, the wallpaper does not suffer from wrinkles or curls that occur when the core layer is laminated with the wallpaper sheet and rolled up. It is also possible to prevent the formation of undulations and unevenness. Therefore, by the method of the present invention, it is possible to form an electromagnetic shielding wall surface that is flat, uniform, and has a desired aesthetic appearance.

Claims (1)

[Claims] 1. An electromagnetic shielding wall covering material comprising a core layer containing a metal thin film and a wallpaper layer covering one side of the core layer. 2. The wall covering material according to claim 1, wherein the conductive metal thin film-containing core layer includes a metal thin film and a conductive metal plating layer covering at least one surface thereof. 3. The wall covering material according to claim 1 or 2, wherein the metal thin film is made of an amorphous metal. 4. The wall covering material according to claim 1 or 2, wherein the metal thin film is made of a non-amorphous metal. 5. Claim 3, wherein the amorphous metal is selected from an amorphous alloy containing Fe as a main component and to which at least one selected from B, Si, C, Co, Ni, and Mo is added. Wall covering materials listed in section. 6. The wall covering material according to claim 3, wherein the metal thin film-containing core layer includes a plurality of narrow metal thin film sheets arranged in parallel with each other. 7. Claim 6, wherein the plurality of metal thin film narrow sheets are bonded to each other at side edges adjacent to each other.
Wall covering materials listed in section. 8. The wall covering material according to claim 1, wherein the metal thin film has a thickness of 200 μm or less. 9. The conductive metal plating layer in the metal thin film-containing core layer,
The wall covering material according to claim 2, having a thickness of 0.1 μm or more. 10. The wall covering material according to claim 1, wherein the metal thin film-containing core layer and the wallpaper layer are bonded together with an adhesive or a pressure-sensitive adhesive. 11. The wall covering material according to claim 1, wherein the metal thin film-containing core layer has a flexible resin coating layer covering at least one side of the metal thin film. 12. The flexible resin coating layer is made of natural rubber, synthetic rubber,
Polyvinyl chloride resin, ethylene-vinyl acetate (EVA)
Claim 11 comprises at least one layer selected from copolymer resins, polyacrylic resins, silicone resins, polyurethane resins, polyethylene resins, polypropylene resins, polyester resins, polyamide resins, and fluorine-containing resins. wall covering material. 13. The wall covering material according to claim 11, wherein the flexible resin coating layer has a thickness of 30 μm or more. 14. The wall covering material according to claim 11, wherein in the metal thin film-containing core layer, both sides of the metal thin film are covered with the flexible resin layer. 15. Claim 11, wherein in the metal thin film-containing core layer, one side of the metal thin film is covered with the flexible resin coating layer, and the other side is covered with the wallpaper layer. wall covering material. 16. The wall according to claim 11, wherein in the metal thin film-containing core layer, the flexible resin coating layer is formed on one side of the metal thin film, and the wallpaper layer is formed thereon. packaging material. 17. The wall covering material according to claim 1, wherein in the metal thin film-containing core layer, a fiber fabric layer is formed on at least one surface of the metal thin film. 18. Affixing a metal thin film-containing core layer to the wall base surface, and pasting a wallpaper sheet on the metal thin film-containing core layer,
A method of forming an electromagnetic wave shielding wall covering material on a wall surface. 19. The method according to claim 18, wherein the metal thin film-containing core layer includes a metal thin film and a conductive metal plating layer covering at least one surface of the metal thin film. 20. The method according to claim 18, wherein the metal thin film-containing core layer has a flexible resin coating layer covering at least one surface of the metal thin film. 21. Claim 1, wherein the wall base surface and the metal thin film-containing core layer are bonded together with an adhesive or a pressure-sensitive adhesive.
The method described in Section 8. 22. When attaching two or more of the metal thin film-containing core layers to the wall base surface in parallel, the edges of the adjacent metal thin films are exposed and electromagnetically bonded to each other;
A method according to claim 18. 23. Claim 18, wherein the metal thin film-containing core layer and the wallpaper sheet are bonded together with an adhesive or a pressure-sensitive adhesive.
The method described in section. 24. When joining and pasting a plurality of the metal thin film-containing core layers in parallel to the wall base surface, and joining and pasting a plurality of the wallpaper sheets in parallel thereon, the joining of the core layers Department and
24. The method according to claim 23, wherein the core layer and the wallpaper sheet are arranged so that the joint portions of the wallpaper sheets do not overlap.