JPH02111000A - Metallic thin film laminate for electromagnetic shielding - Google Patents

Abstract

PURPOSE:To obtain a flexible laminate which protects an electronic equipment or the like against the influence of an electromagnetic wave by a method wherein a metallic thin film laminate, which is composed of two metallic thin film layers and a non-conductive layer interposed between them, is provided to one side or both sides of a non-conductive base of high flexibility. CONSTITUTION:A metallic thin film laminate 20 is composed of two metallic thin film layers 21 and a non-conductive layer 22 interposed between them. The metallic thin film layer 21 is provided to one side or both sides of a flexible non-conductive base 10 of a plastic film such as polyethylene terephthalate, ABS resin, polyacetal, polycarbonate, or the like, or paper, woven fabric, knit, non-woven fabric, or the like. The metallic thin film layer 21 is formed in such a manner that conductive metal such as aluminum, copper, or the like is deposited on one side or both the sides of the flexible non-conductive base 10 through a vacuum deposition method. Paint or bonding agent is applied onto the face of the metallic thin film layer 21 to form the non-conductive layer 22, and the other metallic thin film layer 21 is formed on the face of the non-conductive layer 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a metal thin film laminate for electromagnetic shielding. For more details, please refer to electronic equipment housings, insulated wires, power cable coverings, building materials (floors,
The present invention relates to metal thin film laminates for shielding electromagnetic waves, used for walls, ceilings, curtains, etc., and for packaging electronic devices, magnetic recording media, etc.

[Conventional technology] With the development and spread of electronic devices, C
It has become necessary to protect these devices, magnetic recording bodies, and the like from the adverse effects of static electricity and electromagnetic waves, and there is an increasing demand for sheet materials for shielding electromagnetic waves or sheet materials for packaging as protective materials.

Conventionally, in order to protect electronic equipment, insulated wires, power cables, magnetic recording media, etc. from the effects of electromagnetic waves and static electricity, conductive materials containing carbon black, carbon fiber, short metal fibers, metal phosphorus flakes, or metal powder have been used. Conductive sheets containing

[Problems to be Solved by the Invention] However, the conventional conductive sheet described above has the following drawbacks.

In other words, such conventional conductive sheets cannot be said to be sufficiently effective for protecting electronic equipment, insulated wires, power cables, magnetic recording bodies, etc. from the effects of electromagnetic waves, and Its flexibility was insufficient and it was difficult to fit it into the shape of the equipment to be protected.

In addition, metal foil itself with electromagnetic shielding properties and laminated sheets made by pasting synthetic resin films on metal foils with electromagnetic shielding properties have also been developed, but metal foils and metal foil laminated sheets are hard and insufficiently flexible. Even if this laminated sheet is used to cover and package electronic equipment, insulated wires, power cables, magnetic recording media, etc., it will not fit into these equipment, and the metal foil will easily break or break due to bending or folding. There have been problems in that metal foil laminated sheets have problems in that the constituent layers may peel off from each other.

Furthermore, a laminated sheet is also known in which a metal thin film layer is deposited on one side of a synthetic resin film, and this laminated sheet has excellent flexibility and is used for covering packaging of electronic equipment, insulated wires, power cables, magnetic recording media, etc. However, it has the problem of insufficient electromagnetic shielding properties.

The object of the present invention is to provide a metal thin film laminate for electromagnetic shielding that completely eliminates the various problems mentioned above.

[Means for Solving the Problems] The electromagnetic wave shielding metal thin film laminate of the present invention is made of polyethylene terephthalate, polyphenylene oxide, polyimide, polyphenylene sulfide, polybutylene terephthalate, polypropylene, polyamide, polyethylene, polycarbonate, polystyrene, polyvinyl chloride,
Highly flexible non-conductive group for plastic films such as polyvinylidene chloride, polyvinyl acetate, polymethyl methacrylate, ethylene-vinyl acetate copolymer, ABS resin, polyacetal, paper, woven fabric, knitted fabric, non-woven fabric, etc. Instead of traditional metal foil on one or both sides of the material,
It is characterized by providing a metal thin film laminate including at least two metal thin film layers, with a non-conductive layer interposed between the at least two metal thin film layers.

[Function] In the metal thin M laminate for electromagnetic shielding of the present invention,
Instead of the conventional metal foil, a metal thin film laminate is adopted which includes at least two metal thin film layers and a non-conductive layer is interposed between the at least two metal thin film layers. The layers are polyethylene terephthalate, polyphenylene oxide, polyimide, polyphenylene sulfide, polybutylene terephthalate, polyamide,
Plastic films such as polypropylene, polyethylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polymethyl methacrylate, ethylene-vinyl acetate copolymer, ABS resin, polyacetal, polycarbonate, paper, textiles, knitted fabrics, non-woven fabrics, etc. The metal foil laminated sheet, which is made by attaching a synthetic resin film to a metal foil with electromagnetic shielding properties, is now hard and flexible. Due to insufficient flexibility, this laminated sheet is used for electronic equipment and insulated wires.

Even when used for covering and packaging electrical cables, magnetic recording materials, etc., it does not fit into these devices, and the metal foil easily breaks or leaves creases due to bending or folding, or the end layer constituent layers do not touch each other. This completely eliminates the problem of peeling off from other constituent layers.

The non-conductive base material (10) used in the metal thin film laminate for electromagnetic shielding of the present invention is not particularly limited, but includes, for example, polyethylene terephthalate, polyphenylene oxide, polyimide, polyphenylene sulfide,
Polybutylene terephthalate, polyamide, polypropylene, polyethylene, polystyrene, polyvinyl chloride,
Plastic films such as polyvinylidene chloride, polyvinyl acetate, polymethyl methacrylate, ethylene-vinyl acetate copolymer, ABS resin, polyacetal, polycarbonate, polyester, polyamide, polyamideimide, polyethylene, polypropylene, cellulose acetite, polycarbonate Fabrics, knitted fabrics, nonwoven fabrics, Japanese paper, Western paper, synthetic paper, etc. made of AM such as polyvinyl chloride, acrylic, and rayon are used as appropriate.

The thickness of the non-conductive base material (10) is not particularly limited, but for example, one having a thickness of usually about 2 μs to 5 μm, preferably about 6 μs to 500 μm, is used. If the thickness is less than 2μs, it is too soft and tends to wrinkle, cause uneven processing, and increase product loss, making it impractical.On the other hand, if the thickness exceeds 5ss, the metal thin film for electromagnetic shielding is inflexible and hard. Because it is a laminate, it is unsuitable for anything other than special uses and has little practicality.

If the non-conductive base material (10) has poor adhesion to the metal thin film laminate (20), an undercoat layer (30
) is preferably provided.

There is no particular limit to the thickness of the undercoat layer (30), but it is usually o.
, i~2Q.

Examples of paints forming the undercoat layer (30) include polyester, polyamide, polyamideimide, polyethylene, polypropylene, cellulose acetite, nitrocellulose, polycarbonate, polyvinyl chloride, acrylic resin, acrylic acid lower alkyl ester resin, and urethane resin. , urea-melamine resin, epoxy resin, aminoalkyd resin, unsaturated polyester, phenol resin, and synthetic rubbers such as SBR, NBR, NR, and silicone rubber, or a mixture of two or more thereof can be used.

Metal thin film laminate (20) used in place of conventional metal foil in the metal thin film laminate for electromagnetic shielding of the present invention
If the metal thin film laminate (20) includes at least two metal thin film layers (21) and has a non-conductive layer (22) interposed between the at least two metal thin film layers (21), There are no particular restrictions.

The metal thin film layer (21) is usually made of aluminum, copper,
Nickel, zinc, tin, silver, gold, indium, chromium, platinum, iron, cobalt, molybdenum, titanium, beryllium,
The non-conductive base material (10 ) is formed by vapor deposition on one side or both sides of the undercoat layer (30) with or without the undercoat layer (30), and the thickness thereof is usually 1n~5001
Something as small as a vote is preferable. If the thickness is usually less than 1 nm, sufficient shielding effect cannot be obtained, and if it exceeds 500 n+w, no difference will occur in the shielding effect, and the resulting metal thin film laminate for electromagnetic shielding will lack flexibility, which is not preferable.

Note that the metal thin film layer (21) may be formed by transferring a metal thin film layer formed on a temporary carrier onto the non-conductive base material (10) with or without an adhesive. good.

Since the metal thin film layer (21) is generally susceptible to physical and chemical damage, an overcoat layer may be provided thereon.

Examples of the paint forming the top coat layer (40) include polyester, polyamide, polyamideimide, polyethylene, polypropylene, cellulose acetite, nitrocellulose, polycarbonate, polyvinyl chloride, acrylic resin, acrylic acid lower alkyl ester resin, and urethane resin. , urea-melamine resin, epoxy resin, aminoalkyd resin, unsaturated polyester, phenolic resin, and synthetic rubbers such as SBR, NBR, NR, and silicone rubber, or a mixture of two or more thereof can be used.

The thickness of the top coat layer (40) is usually about 0.1-21.

The thickness of the non-conductive layer (22) is usually not particularly limited, but is usually about 0.1 to 2 μs.

Examples of the paint or adhesive forming the non-conductive layer (22) include polyester, polyamide, polyamideimide, polyethylene, and polypropylene.

Resins such as cellulose acetite, nitrocellulose, polycarbonate, polyvinyl chloride, acrylic resin, acrylic acid lower alkyl ester resin, urethane resin, urea-melamine resin, epoxy resin, aminoalkyd resin, unsaturated polyester, phenolic resin, SBR, N
One or a mixture of two or more synthetic rubbers such as BR, NR, and silicone rubber can be used.

When using a paint that forms a non-conductive layer (22), the paint is usually applied on the surface of the metal thin film layer (21) to form the non-conductive layer (22), and then the non-conductive layer ( 22
) A further metal thin film layer (21) is formed on the surface by a conventional method.

When using an adhesive to form the non-conductive layer (22), the adhesive is usually applied on the surface of the metal thin film layer (21) to form the non-conductive layer (22), and then the non-conductive layer is (2
2) A non-conductive substrate (10) on which another metal thin film layer (21) is formed is attached.

The electromagnetic shielding metal thin film laminate of the present invention obtained in this manner may be used as it is, or it may be cut into thin pieces and used as a thread as it is, or it may be aligned with other ordinary threads or twisted into threads. It is also possible to use yarns that have been twisted or entwined as fabrics, materials, and non-woven fabrics for shielding electromagnetic waves.

[Example] Next, the present invention will be explained with reference to Examples.

Example 1 One was made by forming copper to a thickness of 200 nm on one side of a 12-μs-thick polyethylene terephthalate film by sputtering, and the other was made by forming aluminum on one side of a 9-μs-thick polyethylene terephthalate film by ion-blating. 100 parts of acrylic polyol (parts by weight, the same applies hereafter), hexane, and acrylic polyol were placed on each film, one side with the metal thin film layer facing each other, and the other side with the metal thin film layer facing each other. methylene・
A thin metal film laminate for electromagnetic shielding of the present invention was obtained by bonding through an adhesive layer coated with an adhesive consisting of 5 parts of diisocyanate and 100 parts of ethyl acetate to a thickness of 10 parts using a roll coater.

The obtained metal thin film laminate for electromagnetic shielding of the present invention is as follows:
It is sufficiently effective for protecting electronic equipment, insulated wires, power cables, magnetic recording media, etc. from the effects of electromagnetic waves, and is also flexible enough to fit well into the shape of the equipment to be protected. Visual tests showed no change in the metal surface even after several days had passed.

Example 2 A 1-ounce layer of nickel was formed on one side of a non-woven fabric mainly composed of meta-aramid resin with a basis weight of 40 g/a+" by ion-blating method, and hot-melt polyamide resin was further applied on the same side. Spray coated with 20 g/shoe 2 of the same material, layered in four layers with the coated side and non-woven side facing each other, and then layered one uncoated layer for a total of five layers. temperature 15
0”C, time 15 seconds, pressure 4kg/cm2 (gauge pressure)
Hot pressing was carried out under the following conditions to obtain the metal thin film laminate for electromagnetic shielding of the present invention.

The obtained metal thin film laminate for electromagnetic shielding of the present invention is as follows:
It is sufficiently effective for protecting electronic equipment, insulated wires, power cables, magnetic recording media, etc. from the effects of electromagnetic waves, and is also flexible enough to fit well into the shape of the equipment to be protected. Ta.

Example 3 An ultraviolet curable acrylic resin coating was applied to one side of a 12 μs thick polyethylene terephthalate film using a roll coater, and was irradiated and cured using an ultraviolet lamp.
Copper was sputtered through a gi-type agent layer to a thickness of 20 mm.
Furthermore, lo parts of vinyl chloride-vinyl acetate copolymer, 10 parts of acrylic resin and 5 parts of styrene maleic acid resin were added to 40 parts of methyl ethyl ketone and 4 parts of toluene.
A transfer foil with an adhesive layer was prepared by coating a coating material dissolved in a mixed solvent consisting of 0 parts and 20 parts of ethyl acetate to a thickness of IOQ using a roll coater.

Transfer the above transfer foil onto kraft paper with a basis weight of 45 g/m at a temperature of 1.
After thermal transfer using a silicone rubber roll at 50°C and peeling off the base film, repeat the transfer process four more times.
A metal thin film laminate for electromagnetic shielding of the present invention was obtained.

The obtained metal thin film laminate for electromagnetic shielding of the present invention is as follows:
It is sufficiently effective (same level as that of Example 1) for the purpose of protecting electronic equipment, insulated wires, power cables, magnetic recording bodies, etc. from the effects of electromagnetic waves, and is also sufficiently flexible to be protected. Fits well to the shape of the device, 1
Even after 0 days had passed, no change was observed on the metal surface in a visual test.

Comparative Example 1 A thin aluminum film layer was deposited on one side of a polyethylene terephthalate film with a thickness of 2 μs using a resistance heating vacuum evaporation method.
00n■ to obtain a metal thin film laminate for electromagnetic shielding.

The obtained metal thin film laminate for electromagnetic shielding of the present invention is as follows:
For the purpose of protecting electronic equipment, insulated wires, power cables, magnetic recording media, etc. from the effects of electromagnetic waves, there were dissatisfaction with the effectiveness of the product, or it was flexible enough to fit well into the shape of the equipment to be protected. Even after 10 days, no change was observed on the metal surface by visual inspection.

Comparative Example 2 An aluminum foil having a thickness of 7 μs was bonded to one side of a polyethylene terephthalate film having a thickness of 6 μs by a dry lamination method to obtain a metal thin film laminate for electromagnetic shielding.

The obtained metal thin film laminate for electromagnetic shielding of the present invention is as follows:
It is sufficiently effective for protecting electronic equipment, insulated wires, power cables, magnetic recording materials, etc. from the effects of electromagnetic waves, and even after 10 days, visual tests showed no change in the metal surface. However, it lacked flexibility and did not fit the shape of the equipment to be protected, making it difficult to use.

Comparative Example 3 A copper foil having a thickness of 9 μs was bonded to one side of a polyethylene terephthalate film having a thickness of 12 μs by a dry lamination method to obtain a metal thin film laminate for electromagnetic shielding.

The obtained metal thin film laminate for electromagnetic shielding of the present invention is as follows:
Although it was sufficiently effective for the purpose of protecting electronic equipment, insulated wires, power cables, magnetic recording media, etc. from the effects of electromagnetic waves, visual tests after 10 days showed changes in the metal surface, indicating that the corrosion resistance had deteriorated. Moreover, it lacked flexibility and did not fit the shape of the equipment to be protected, making it difficult to use.

Table 1 shows the electromagnetic shielding properties of the metal thin film laminates for electromagnetic shielding of the present invention obtained in Examples 1 to 3 and those of Comparative Examples 1 to 3.

The electromagnetic shielding characteristics were measured in the range of 1 to 100,100 O by the Kansai Electronics Promotion Center, KEC method (electric field mode).

Table 1 [Effects of the Invention] As is clear from Examples 1 to 3 and Comparative Examples 1 to 3, the electromagnetic wave shielding metal thin film laminate of the present invention can be used for electronic equipment, insulated wires, power cables, magnetic recording bodies, etc. It was sufficiently effective for the purpose of protecting against the effects of electromagnetic waves, and was also flexible enough to easily fit into the shape of the equipment to be protected.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing the basic structure of the metal thin film laminate for electromagnetic shielding of the present invention, and FIG. 2 is a schematic perspective view showing another embodiment of the metal thin film laminate for electromagnetic shielding of the present invention. 3 is a schematic partially enlarged sectional view showing the basic structure of the metal thin film laminate for electromagnetic shielding of the present invention, and FIG. 4 shows another embodiment of the metal thin film laminate for electromagnetic shielding of the present invention. FIG. 3 is a schematic partially enlarged sectional view. (Numbers in drawings) (10): Non-conductive base material (20): Metal thin film laminate (21): Metal thin film layer (22): Non-conductive layer (30): Undercoat layer (40): Top coat layer

Claims (1)

[Claims] 1. A metal thin film laminate for electromagnetic wave shielding comprising at least two metal thin film layers, characterized in that a non-conductive layer is interposed between the at least two metal thin film layers. .