JP2000286592A - Filter for shielding electromagnetic waves - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin and light filter for shielding electromagnetic waves which keeps superior viscosity, even if it meets the hear radiation from the surface of a display, and in which there is no occurrence of bubbles at an adhesive face. SOLUTION: For a filter for shielding electromagnetic waves, a transparent conductive film layer is made on one side of a transparent plastic film, and an adhesive layer 10 g/cm in viscosity at 80 deg.C is made on the other side, and the thickness of the transparent plastic film is 25-300 μm. Furthermore, for the transparent conductive film layer, high refractive index transparent films (a) and metallic film layers b are stacked alternately at least two times repeatedly, and the lowermost layer and the uppermost layer are formed of (a), and moreover the sheet resistivity is 0.5-10 Ω/(square), and the full beam transmissivity is 50% or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a filter for shielding electromagnetic waves. Specifically, plasma display (PDP), cathode ray tube (CRT), liquid crystal display (L
The present invention relates to a filter for shielding electromagnetic waves used to reduce electromagnetic waves generated from a display such as a CD.

[0002]

2. Description of the Related Art In recent years, society has become highly computerized. As a result, the technology for information-related equipment and related parts has remarkably advanced and spread.
Among them, display devices are used for televisions, personal computers, for displaying guidance at stations and airports, and for providing various other types of information. Display devices have been required to have various characteristics in order to use them for various applications.
It has been required to be thin. In those demands, as a large and thin display,
A plasma display (PDP) has attracted attention. However, the plasma display has a problem of generating a strong leakage electromagnetic field due to a problem in principle. In recent years, the influence of the leaked electromagnetic field has been of particular interest, and it is particularly necessary to prevent the influence on the human body and other electronic devices. Further, from the plasma display device, there is a possibility that near infrared light generated from excited atoms in the plasma acts on electronic devices such as a cordless phone and a remote controller to cause a malfunction.

For this reason, display devices, especially PDPs
Uses a filter (filter for electromagnetic wave shielding) for shielding a leakage electromagnetic field and near-infrared light. At present, shielding materials for near-infrared rays and electromagnetic fields can be broadly divided into grounded metal meshes, synthetic resin or metal fiber meshes coated with metal, and combinations of dyes that absorb near-infrared rays. ,
There is a combination of a transparent conductive thin film typified by indium tin oxide (ITO) and (in some cases) a dye that absorbs near infrared rays.

[0004] For example, Japanese Patent Application Laid-Open No. 9-33
No. 0667 discloses an electromagnetic wave shielding plate formed by applying a conductive paste in a mesh form on a transparent resin plate and drying the paste. Further, as an example of Japanese Patent Laid-Open No.
No. 73719, a high refractive index transparent thin film layer (D) and a metal thin film layer (E) are sequentially repeated (D) / (E) on one main surface of a transparent polymer film. An optical filter for a display, in which a light control film having a high-refractive-index transparent thin film layer (D) and a transparent resin layer formed thereon, which are repeatedly laminated four or more times as a unit, is further exemplified. When these electromagnetic wave shielding layers are used, it is possible to efficiently shield electromagnetic waves and near infrared rays generated from the housing. In particular, in the latter example, a transparent conductive thin film is used as the electromagnetic wave shielding layer, and there is no generation of a light-shielding portion or moiré by the mesh as compared with the former, which is particularly preferable. These electromagnetic wave shielding layers themselves are used together with a supporting plate such as a glass plate or a plastic plate due to insufficient mechanical strength.

On the other hand, as described above, it is necessary to reduce the thickness and weight of the display device. In particular, P
The DP is expected to be applied to wall-mounted displays because the housing itself can be easily made thinner and lighter. However, when the above-described electromagnetic wave filter with a support plate is used, it is difficult to reduce the thickness and weight of the display due to the support plate. For this reason, thinner and lighter support plates have been studied.However, in the case of a glass plate, the support plate is liable to break when thinned, and in the case of a plastic plate, the mechanical strength is lost. There was a limit to reducing weight and weight. In addition, it was studied to directly attach a plastic film on which an electromagnetic wave shielding layer was formed directly to the housing.
However, problems such as the generation of bubbles with the passage of time and the peeling of the plastic film from the casing in severe cases have occurred.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to maintain excellent adhesiveness even when radiating heat from a display surface, and to reduce the thickness and weight of the adhesive surface without generating bubbles. An object of the present invention is to provide a simplified filter for shielding electromagnetic waves.

[0007]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, the plastic film on which the electromagnetic wave shielding layer is formed is directly attached to the display housing to reduce the thickness. The weight reduction is possible, the problem of bubbles and peeling that had been a problem when directly attached was caused by the high temperature of the display surface, the peeling of the adhesive was on the display side, and a transparent plastic film It was found that it could occur on both sides, that it occurred on the side with poorer adhesion, and that the surface temperature of the display was about 70 ° C. The inventors have found that these problems can be solved by forming an adhesive layer having a specific adhesive strength on the opposite surface of the transparent plastic film on which the electromagnetic wave shielding layer is formed, and have completed the present invention.

That is, the present invention provides a filter for electromagnetic wave shielding comprising a transparent conductive thin film layer formed on one side of a transparent plastic film and an adhesive layer having an adhesive strength at 80 ° C. of at least 10 g / cm on the other side. It is.

In a preferred embodiment of the filter for shielding electromagnetic waves according to the present invention, a transparent conductive thin film layer is formed by alternately repeating a high refractive index transparent thin film layer (a) and a metal thin film layer (b) at least twice. The lower layer and the uppermost layer are formed by (a), and the surface resistivity is 0.5 to
The above-mentioned filter for electromagnetic wave shielding having 10 Ω / □ and a total light transmittance of 50% or more is exemplified. In this case, the high-refractive-index transparent thin film layer (a) is preferably formed of a metal oxide or a metal sulfide. In particular, at least one metal selected from indium-tin oxide, indium oxide, and tin oxide It is preferably an oxide thin film layer. On the other hand, the metal thin film layer (b) is preferably a thin film layer of silver or a silver alloy. The pressure-sensitive adhesive layer is preferably formed of an acrylic pressure-sensitive adhesive. The overall thickness of the filter for electromagnetic wave shielding according to the present invention comprising the above-mentioned laminate is about 25 to 350 μm.

[0010] The filter for shielding electromagnetic waves of the present invention comprises:
Even when the heat is dissipated from the display surface, no bubbles are generated and excellent adhesiveness is maintained. In addition, there is no need to use a support plate or the like when affixing to the display surface, and it is possible to reduce the thickness and weight. Therefore, the filter for shielding electromagnetic waves of the present invention is extremely useful as a filter for shielding electromagnetic waves for display devices including plasma displays, cathode ray tubes, and liquid crystal display devices.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The filter for electromagnetic wave shielding according to the present invention has a transparent conductive thin film layer which is an electromagnetic wave shielding layer formed on one surface of a transparent plastic film, and has a specific adhesive strength on another surface. It is manufactured by forming an agent layer.

The transparent plastic film used in the present invention is not particularly limited as long as it is transparent. For example, polyethylene terephthalate, polyether sulfone,
Examples include homopolymers such as polyarylate, polyacrylate, polycarbonate, polyetheretherketone, polyethylene, polyester, polypropylene, polyamide, and polyimide, and polymer films composed of copolymers of monomers of these resins and copolymerizable monomers. .

As a method for forming the transparent plastic film, it is possible to use a known plastic film production method such as a melt extrusion method, a casting method, and a calendar method. In addition, the transparent conductive thin film layer described later has a transmission color
Both the reflection colors are colored and may be undesired colors. In order to correct the color at that time, the transparent plastic film can be colored. As a method of coloring, a method of forming a film after previously mixing with a dye when forming the plastic film, a method of dispersing the dye in a resin to form an ink, coating and drying, a method of bonding a colored plastic film, and the like Is mentioned.

The total light transmittance of the transparent plastic film is preferably 70% or more. More preferably, it is at least 75%. Most preferably, it is at least 80%. Generally, the total light transmittance of these transparent plastic films does not exceed 92%. However, it is possible to exceed the above value by increasing the light transmittance by forming an antireflection layer or the like. The thickness of the transparent plastic film is 25 to 30 from the viewpoint of handleability.
About 0 μm is preferable. Furthermore, for the purpose of improving the adhesion with the transparent conductive thin film layer which is an electromagnetic wave shielding layer, the surface on which the transparent conductive thin film layer is to be formed is, for example, an aqueous polyurethane-based or silicon-based coating agent. It is also possible to form an underlayer for improvement. Also,
By modifying the surface of the transparent plastic film, the adhesion is improved and the hand is good. Examples of the surface modification method include physical methods such as corona discharge treatment and plasma glow treatment.

In the present invention, a transparent conductive thin film is preferably used as the electromagnetic wave shielding layer. Unlike a mesh, the transparent conductive thin film covers the entire electromagnetic wave shielding surface, and does not reduce the display resolution of the display. In addition, it also has near-infrared reflectivity, and has many excellent features such as being capable of being processed in a roll form, and can be an electromagnetic wave shielding layer well suited to the purpose of the present invention.

Conventionally, as an electromagnetic wave shielding layer, other than this, there are a metal mesh, a conductive paste obtained by dispersing a metal in a resin, applied in a mesh shape and dried, and the mesh itself transmits light. Therefore, there is a problem that a portion that does not transmit light appears, a moire occurs, a disconnection portion occurs when a mesh is formed, and a yield is deteriorated.

The transparent conductive thin film layer, which is an electromagnetic wave shielding layer, is preferably formed on one surface of a transparent plastic film. If it is formed on both surfaces, it is difficult to ground the electromagnetic wave shielding layer, which is not preferable. The transparent conductive thin film in the present invention preferably comprises a high refractive index thin film layer and a metal thin film layer. Generally, in the case of a metal oxide-based transparent conductive thin film layer alone such as indium tin oxide (ITO) or zinc oxide (ZnO) which is known as a transparent conductive thin film, in order to lower the surface resistance value, It is necessary to make the thin film layer thick, and in that case, the total light transmittance is greatly reduced, which is not preferable. Further, it is preferable that the high refractive index transparent thin film layer and the metal thin film layer are repeatedly laminated. In this case, the outermost surface layer is preferably a high refractive index transparent thin film layer. When the outermost surface layer is a metal thin film layer, an interface that directly reflects between the air layer or the resin layer and the metal layer is formed, so that light reflection is increased and light transmittance is significantly reduced, which is not preferable. . Further, the metal layer may be directly exposed to the outside air, and the deterioration of the metal layer may progress. It is not preferable from this viewpoint.

The number of times of lamination is preferably two or more. 3-6 times are more preferred. If the number of repeated laminations is larger than the above range, the error in the thickness of each layer will greatly affect the accuracy of the overall optical characteristics,
Moreover, it is not preferable because productivity is deteriorated. In addition, if the number of repeated laminations is small, the thickness of each metal thin film layer must be increased in order to effectively shield electromagnetic waves.
In this case, since the reflection intensity is increased, the total light transmittance is significantly reduced, and it becomes difficult to achieve the required optical characteristics, which is not preferable.

The transparent conductive thin film layer used in the present invention preferably has a surface resistivity of 0.5 to 10 Ω / □.
More preferably, it is 0.7 to 5 Ω / □. When the surface resistivity is within the above range, it is possible to achieve both good electromagnetic wave shielding characteristics and good optical characteristics. If the surface resistivity is lower than the above range, the electromagnetic wave shielding characteristics themselves are good, but the light transmittance is undesirably reduced, which is not preferable. On the other hand, if the surface resistivity is higher than the above range, the optical characteristics are good, but the electromagnetic wave shielding characteristics are poor, which is not preferable.

The total light transmittance of the transparent conductive thin film is 50.
%, More preferably 60% or more. Most preferably, it is at least 65%. It is not preferable to mount an electromagnetic wave filter using a transparent conductive thin film layer having a total light transmittance lower than these values on a display, since the screen becomes dark. As described above, in the present invention, a part of the transparent conductive thin film layer is formed of the metal thin film layer. Therefore, even if the thicknesses of the metal thin film layer and the high-refractive-index transparent thin film layer are optically optimized, the absorption and reflection of metal light by the metal thin film layer cannot be avoided. Therefore, the upper limit of the total light transmittance of the transparent conductive thin film layer used in the present invention is usually 8
It is about 0%.

The material of the high refractive index transparent thin film layer used in the present invention is not particularly limited, but a material having a refractive index of preferably 1.6 or more, more preferably 1.8 or more is preferable. Specific materials that can form such a high-refractive-index transparent thin film layer include indium, titanium, zirconium, bismuth, tin, zinc, antimony, tantalum,
Oxides or sulfides such as cerium, neodymium, lanthanum, thorium, magnesium, and gallium, mixtures of these oxides or sulfides, and composite oxides.
These oxides or sulfides may have a difference in the stoichiometric composition between the metal and oxygen or sulfur as long as the optical characteristics are not significantly changed. Among these materials, indium oxide, indium-tin oxide (IT
O), tin oxide, and the like can be preferably used because they have high transparency and a high refractive index, and also have a high film forming speed and good adhesion to a metal thin film layer.

The thickness of the high-refractive-index transparent thin film layer is determined from the required optical characteristics and is not particularly limited, but the thickness of each layer is preferably 5 to 200 nm.
10-100 nm is more preferred. Also, as described above, the high-refractive-index transparent thin film layers are repeatedly and alternately laminated with the metal thin-film layers, but each high-refractive-index transparent thin film layer does not need to be made of the same material, and has the same thickness. There is no need to be. Known methods such as a sputtering method, an ion plating method, an ion beam assist method, a vacuum evaporation method, and a wet coating method can be used as a method for forming the high refractive index transparent thin film layer. That is, first, a first high refractive index transparent thin film layer is formed on one surface of a transparent plastic film, and a first metal thin film layer is formed on the surface of the high refractive index transparent thin film layer. Thereafter, the high-refractive-index transparent thin film layer and the metal thin-film layer are alternately and repeatedly laminated, and finally, the uppermost layer is a high-refractive-index transparent thin film layer.

The material of the metal thin film layer may be silver, gold, platinum, palladium, nickel, chromium, zinc, zirconium, titanium, tungsten, tin, etc., or an alloy containing at least one metal selected from these. No. Among them, silver can be preferably used because of its low surface resistivity, good infrared reflection characteristics, and excellent total light transmission characteristics when laminated with a high refractive index transparent thin film layer. However, since silver has poor chemical and physical stability, it is easily degraded by pollutants, moisture, heat and light in the environment. Therefore, an alloy of silver and one or more environmentally stable metals such as gold, platinum, palladium, and indium can be preferably used.

The thickness of each metal thin film layer is preferably not more than 4 nm because it is preferably not an island structure, and is preferably 30 nm or less from the viewpoint of transparency. However, even when the thickness is larger than the above range, the total light transmittance of the filter is 4
If it is 0% or more, it can be used. As in the case of the high-refractive-index transparent thin film layer, the thickness of each metal thin film layer does not need to be the same, nor does it need to be the same material. As the method for forming the metal thin film layer, the above-described method for forming the high refractive index transparent thin film layer can be used as it is.

For the purpose of preventing the deterioration of the transparent conductive thin film layer, particularly the metal thin film layer, it is possible to seal the peripheral end of the transparent conductive thin film layer. For example, a transparent resin containing a triazineamine-based compound, a thiodipropionate-based compound, a benzimidazole-based compound, or the like, or a resin containing these compounds can be used for the above purpose. In addition, a protective layer can be provided on the outermost surface of the transparent conductive thin film layer for the purpose of improving scratch resistance, antireflection performance, and environmental resistance. Examples of the method for forming the protective layer include a method of directly applying a resin containing an active ingredient, and a method of bonding the resin to a protective film.

The filter for shielding electromagnetic waves of the present invention can of course be grounded to remove shielded electromagnetic waves. Examples of the grounding method include a method generally used, for example, a method of electrically connecting a metal wire such as copper to a peripheral end of the transparent conductive thin film layer. In the filter for shielding electromagnetic waves of the present invention, an adhesive layer is formed on one surface of the transparent plastic film (the surface on which the transparent conductive thin film layer is not formed). It is possible to directly adhere to the display body via this adhesive layer. By directly bonding the main body of the display and the filter for shielding electromagnetic waves, there is no need to use a support plate, which was indispensable for conventional filters for shielding electromagnetic waves, and the entire display can be made thinner and lighter. Become.

In general, the surface of a display is made of glass, and therefore, a transparent plastic film and a glass plate are bonded using an adhesive layer. If bubbles occur on the adhesive surface or peeling occurs, the image will be distorted,
There arises a problem that the display color looks different from the original display color. In any case, the problem of bubbles and peeling is caused by the peeling of the pressure-sensitive adhesive layer from the plastic film or the glass plate. This phenomenon is
There is a possibility that it may occur on both the plastic film side and the glass plate side, and peeling will occur on the side with weaker adhesion. Therefore, the adhesive layer and plastic film at high temperature
It is necessary that the adhesion to the glass plate be high. Specifically, the adhesive strength between the transparent plastic film and the glass plate and the adhesive layer is preferably 10 g / cm or more at 80 ° C. More preferably, it is 30 g or more. Higher adhesive strength is preferred for the purpose of the present invention. However, an adhesive that exceeds 2000 g / cm
In some cases, the bonding operation becomes difficult, which is not preferable. In order to protect the surface of the pressure-sensitive adhesive layer (the surface not in contact with the transparent plastic film), an easily peelable film or the like (separator) can be provided.

The adhesive layer is preferably transparent. Specifically, the total light transmittance of the pressure-sensitive adhesive layer is preferably 70% or more. 80% or more is more preferable, and 85 to 92% is most preferable. Further, the haze is preferably low. Specifically, 0 to 3% is preferable, and 0 to 1.5% is more preferable. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer according to the present invention is preferably colorless so as not to change the original display color of the display. However, even if the resin itself is colored, it can be considered substantially colorless if the thickness of the pressure-sensitive adhesive layer is small. Further, the case where coloring is intentionally performed as described later is also outside this range.

Examples of the pressure-sensitive adhesive having the above characteristics include acrylic resins, α-olefin resins, vinyl acetate resins, acrylic copolymer resins, urethane resins, epoxy resins, vinylidene chloride resins, chloride resins, and the like. Examples include vinyl resins, ethylene-vinyl acetate resins, polyamide resins, polyester resins, and the like. Of these, acrylic resins are preferred. Even when the same resin is used, the tackiness is improved by reducing the amount of cross-linking agent added, adding a tackifier, or changing the terminal group of the molecule when synthesizing the adhesive or adhesive by polymerization. It may be made to be. As a commercially available product that can be preferably used, product name: SK Dyne 1473 manufactured by Soken Chemical Co., Ltd.
H, SK Dyne 101LV, manufactured by Unitika Ltd., trade name: Elitel 3230, and the like. Incidentally, the pressure-sensitive adhesive layer in the present invention may be formed of a material usually called an adhesive.

From the viewpoints of transparency, colorlessness, and handling properties, the thickness of the pressure-sensitive adhesive layer is preferably about 1 to 50 μm. When the pressure-sensitive adhesive layer is formed with an adhesive, the thickness of the pressure-sensitive adhesive layer should be reduced within the above range. Specifically, 1-20μ
m is preferable. When forming with an adhesive, the thickness of an adhesive layer is made thicker in the said range. Specifically, 5-50μ
m is preferable. However, in the case where the display color of the display itself is not changed and the transparency has the above characteristics, the thickness may exceed the above range in some cases.

The transparent conductive thin film layer used in the present invention is usually colored, and may change the display color of the display itself. In order to adjust the transmission color as a filter, it is also possible to positively color by adding a dye or pigment to the pressure-sensitive adhesive layer.

The filter for shielding electromagnetic waves according to the present invention produced as described above has a total light transmittance of 40.
% Is preferable. It is more preferably at least 50%, most preferably at least 60%. If the total light transmittance is lower than the above value, the display screen becomes dark, which is not preferable. In addition, since a metal thin film layer is used for the transparent conductive thin film used in the present invention, the total light transmittance does not generally exceed 78%. Also,
The overall thickness is about 25 to 350 μm.

[0033]

The present invention will be described below with reference to examples. Evaluation items and evaluation methods were performed as follows. (1) Filter Thickness (mm) The sample obtained in the example or the comparative example was cut out to a width of 100 cm and a length of 100 cm, and a caliper [manufactured by Mitutoyo Corporation;
Model: digmatic caliper], randomly select 10 locations, measure the thickness, and calculate the average value. (2) Weight of filter (g) Three samples similar to those in the preceding paragraph were prepared, and the weight was measured using an electronic balance [manufactured by A & D Corporation, model: EP-41KA]. calculate.

(3) Confirmation of Air Bubbles and Identification of Separated Surface A filter is adhered to the entire surface of a commercially available plasma display (manufactured by NEC Corporation, Model: Plasma X42 type) and left for 48 hours with an image taken After that, the number of bubbles having a diameter of 0.5 mm or more was counted. When air bubbles were observed, the air bubble portion was cut off, and the layer where the air bubbles were generated was confirmed.

(4) Adhesive force (g / cm) The same adhesive layer or adhesive layer as that constituting the filter is sandblasted (alumina particles having a diameter of 0.3 mm are sprayed at a discharge pressure of 4 kg / cm ²⁾ . )), The same pressure-sensitive adhesive layer as in the example or the comparative example was formed on a 0.3 mm-thick aluminum plate, and the transparent plastic film or the transparent glass plate used in each example was bonded to the surface thereof. . After bonding, the sample was allowed to stand at 80 ° C. for 24 hours, and the sample was cut into a width of 2.5 cm and a length of 10 cm, and an autograph [manufactured by Shimadzu Corporation;
GS-100D], the peeling stress between the pressure-sensitive adhesive layer and the transparent plastic film, and between the pressure-sensitive adhesive layer and the glass plate (peeling angle: 90 °, peeling speed: 100 mm / min)
Are evaluated in an environment of 80 ° C., respectively, and are regarded as adhesive strength.

(5) Total light transmittance (%) spectrophotometer [manufactured by Nippon Denshoku Co., Ltd., type: NDR-200]
0]. For a transparent plastic film, measurement is performed on the sample used in each of the examples. Regarding the transparent conductive thin film layer, the same transparent conductive thin film layer as in each example was formed on one side of a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., trade name: A4100) having a thickness of 188 μm, and used as a sample. . That is, P
A laminate of the ET film layer and the transparent conductive thin film layer is used as a sample. (6) Surface resistivity (Ω / □) 4-probe surface resistivity meter [Mitsubishi Chemical Corporation, Model:
Using LORESTA SP], ten measurement points are randomly selected and measured, and the average value is calculated to obtain the surface resistivity.

Example 1 Polyethylene terephthalate (PE) having a thickness of 188 μm
T) Film (manufactured by Toyobo Co., Ltd., trade name: A410)
0) has a laminated structure of indium oxide thin film / silver thin film / indium oxide thin film / silver thin film / indium oxide thin film / silver thin film / indium oxide thin film on one main surface, each having a thickness of 40/10/80/10. / 80/10 / 40n
The transparent conductive thin film layer having a thickness of m was laminated to obtain a transparent conductive film. An acrylic two-liquid crosslinkable pressure-sensitive adhesive (manufactured by Soken Chemical Co., Ltd., trade name: SK Dyne 147) is formed on the main surface of the obtained transparent conductive film on which the transparent conductive thin film layer is not formed.
3H) was applied by a reverse coating method so that the thickness after drying became 25 μm, and was dried at 80 ° C. for 2 minutes by a blow dryer to form an adhesive layer, thereby obtaining a filter for electromagnetic wave shielding. The weight and thickness of the filter, confirmation of air bubbles and identification of the peeled surface, adhesive strength, and total light transmittance and surface resistivity of the transparent conductive layer were measured by the above method, and the obtained results are shown in [Table 1]. . The indium oxide thin film was formed by using indium as a target, evacuating the pressure to 0.001 Pa, and then reducing the total pressure to 0.11 Pa.
Argon gas was introduced until the pressure became 3 Pa, and oxygen gas was further introduced so that the total pressure became 0.26 Pa. In this state, a magnetron DC sputtering method was used. The silver thin film was formed by using silver as a target, evacuating to a pressure of 0.001 Pa, and then introducing an argon gas to a total pressure of 0.26 Pa. In this state, a magnetron DC sputtering method was used.

Example 2 Example 1 was repeated except that the acrylic two-liquid crosslinkable adhesive was SK Dyne 101 VLV manufactured by Soken Chemical Co., Ltd.
In the same manner as in the above, an electromagnetic wave shielding filter having an adhesive layer on one side was obtained. The results obtained are shown in [Table 1]. The same evaluation as in Example 1 was performed.

Example 3 Polyester-based hot melt adhesive [Unitika Co., Ltd.
Product name: ELITEL 3230] having a thickness of 5 after drying.
A filter for electromagnetic wave shielding having an adhesive layer on one side was obtained in the same manner as in Example 1 except that the coating was performed so as to have a thickness of μm.

Comparative Example 1 An electromagnetic wave shield having a pressure-sensitive adhesive layer on one side in the same manner as in Example 1 except that the acrylic two-liquid crosslinkable pressure-sensitive adhesive was changed to SK Dyne SR-3 manufactured by Soken Chemical Co., Ltd. Filter was obtained.

Comparative Example 2 The filter for electromagnetic wave shielding having an adhesive layer on one side prepared in Comparative Example 1 was bonded to a glass plate having a thickness of 3 mm to obtain a filter for electromagnetic wave shielding. The thickness and weight of the obtained electromagnetic wave shielding filter were measured, placed on a display, and confirmation of bubbles and identification of the peeled surface were performed.

[0042]

[Table 1]

<Description of Table 1> The thickness and weight described in [Table 1] are the thickness and weight of the electromagnetic wave shielding filter, and the adhesive strength A is the adhesive strength with the transparent plastic film and the adhesive strength B.
Means the adhesive force to the glass surface, the surface resistivity and the total light transmittance mean the surface resistivity and the total light transmittance of the transparent conductive layer.

[0044]

The filter for shielding electromagnetic waves according to the present invention does not generate air bubbles and maintains excellent adhesiveness even when heat is released from the display surface. In addition, there is no need to use a support plate or the like when affixing to the display surface, and it is possible to reduce the thickness and weight. Therefore, the filter for electromagnetic wave shielding of the present invention is a plasma display,
It is extremely useful as a filter for electromagnetic wave shielding for a display device including a CRT and a liquid crystal display device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 29/89 G02B 1/10 Z (72) Inventor Akira Suzuki 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Prefecture. Address Mitsui Chemicals Co., Ltd. (72) Yuichiro Harada, Inventor 2-1-1 Tangodori, Minami-ku, Nagoya-shi, Aichi Prefecture Mitsui Chemicals Co., Ltd. (72) Inventor Sakai F-term (Reference) 2H048 GA01 GA07 GA09 GA11 GA26 GA33 GA60 GA61 2K009 BB24 CC02 CC03 CC24 DD02 DD04 EE03 5C032 AA02 AA07 EE03 EE17 EF02 EF05 5C040 MA08 5E321 AA04 BB23 BB25 CC16 GG05 GH01

Claims (13)

[Claims] 1. An electromagnetic wave shielding filter comprising a transparent plastic film, a transparent conductive thin film layer formed on one side, and an adhesive layer having an adhesive strength at 80 ° C. of at least 10 g / cm on the other side. 2. The transparent plastic film has a thickness of 25.
The filter for shielding electromagnetic waves according to claim 1, which has a thickness of from 300 to 300 µm. 3. A transparent conductive thin film layer comprising a high refractive index transparent thin film layer (a) and a metal thin film layer (b) alternately and repeatedly laminated at least twice, wherein the lowermost layer and the uppermost layer are formed of (a). The filter for electromagnetic wave shielding according to claim 1, wherein the filter has a surface resistivity of 0.5 to 10 Ω / □ and a total light transmittance of 50% or more. 4. The filter for shielding electromagnetic waves according to claim 3, wherein the high refractive index transparent thin film layer (a) is a transparent thin film layer formed of a metal oxide or a metal sulfide. 5. The filter according to claim 3, wherein the high-refractive-index transparent thin film layer (a) is at least one kind of thin film layer selected from indium-tin oxide, indium oxide and tin oxide. 6. The thickness of each high refractive index transparent thin film layer (a) is 5
The filter for shielding electromagnetic waves according to claim 3, wherein the thickness is from 200 to 200 nm. 7. The filter according to claim 3, wherein the metal thin film layer (b) is a silver or silver alloy thin film layer. 8. The thickness of each metal thin film layer (b) is 4 to 30 n
4. The filter for shielding electromagnetic waves according to claim 3, wherein m is m. 9. The filter according to claim 1, wherein the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive. 10. An adhesive layer having an adhesive strength at 80 ° C. of 1
The filter for shielding electromagnetic waves according to claim 1, wherein the filter weight is 0 to 2000 g / cm. 11. The filter according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 50 μm. 12. The filter according to claim 1, wherein the thickness is 25 to 350 μm. 13. The filter for shielding electromagnetic waves according to claim 1, which is a filter for shielding electromagnetic waves for a display device including a plasma display, a cathode ray tube, and a liquid crystal display device.