JPH1075087A - Adhesive film having electromagnetic wave shielding property and infrared ray screen property, and display using the film, and electromagnetic wave screen structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive film which is superior in shielding properties of electromagnetic waves, generated from the front of a display and also has infrared ray screen property, transparency, invisibility, and favorable adhesive property, and displays or the like using it. SOLUTION: In the constituent material which is provided with a geometrical figure made of conductive material on the surface of plastic base material, the width of the line constituting the geometrical figure is 40μm or under, and the interval between the lines is 200μm or over, and the thickness of the line is 40μm or under, and a part or the whole of the base material including the geometrical figure is covered with an adhesive, and the difference of refractive indices between the adhesive covering the geometric figure and the plastic base material is made to be 0.14 or smaller. Or in case that the plastic base material is stacked on the conductive material through an adhesive layer, the difference of refractive indices between the adhesive layer and the adhesive layer covering the geometrical figure is made 0.14 or smaller, and material having absorption in the infrared region is applied within the adhesive or on the adhesive face or on the rear of a film, whereby an adhesive film which has electromagnetic shield property and infrared ray screen property is obtained and is used for a display or an electromagnetic wave shielding structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive film having a shielding property of an electromagnetic wave generated from the front surface of a display such as a CRT, a PDP (plasma), a liquid crystal and an EL and an infrared shielding property, a display using the adhesive film, and an electromagnetic wave. It relates to a shielding structure.

[0002]

2. Description of the Related Art With the recent increase in the use of various types of electrical equipment and electronic equipment, electromagnetic noise interference (Electrically
o-Magnetic Interference (EMI) is also on the rise. Noise can be roughly divided into conducted noise and radiated noise. As a measure against conduction noise, there is a method using a noise filter or the like. On the other hand, as a measure against radiation noise, it is necessary to insulate the space electromagnetically,
Methods such as making the housing a metal body or a high conductor, inserting a metal plate between circuit boards, and winding a cable with metal foil have been adopted. Although these methods can expect an electromagnetic wave shielding effect of a circuit or a power supply block, they are not suitable for shielding electromagnetic waves generated from the front surface of a display such as a CRT and a PDP because they are opaque.

As a method for achieving both the electromagnetic wave shielding property and the transparency, a method of forming a thin film conductive layer by depositing a metal or metal oxide on a transparent substrate (Japanese Patent Laid-Open No. 27880/1990).
No. 0, JP-A-5-323101). On the other hand, an electromagnetic wave shielding material in which a good conductive fiber is embedded in a transparent substrate (JP-A-5-327274,
JP-A-5-269912) or an electromagnetic wave shielding material in which a conductive resin containing metal powder or the like is directly printed on a transparent substrate (JP-A-62-57297, JP-A-2-5-5).
Further, an electromagnetic wave shielding material in which a transparent resin layer is formed on a transparent substrate such as polycarbonate having a thickness of about 2 mm and a copper mesh pattern is formed thereon by an electroless plating method (see Japanese Patent Application Laid-Open No. 5-2838
No. 89) has been proposed.

[0004]

As a method for achieving both the electromagnetic wave shielding property and the transparency, Japanese Patent Application Laid-Open No. 1-278800 has been disclosed.
In the method of forming a thin film conductive layer by depositing a metal or metal oxide on a transparent substrate disclosed in Japanese Patent Application Laid-Open No. If it is 100 ° to 2,000 °), the surface resistance of the conductive layer becomes too large, so that 30 required at 1 GHz is used.
The shielding effect of not less than 20 dB was insufficient at 20 dB or less. An electromagnetic wave shielding material in which a good conductive fiber is embedded in a transparent substrate (JP-A-5-327274, JP-A-5-327274)
In Japanese Patent Application Laid-Open No. 269912), the electromagnetic wave shielding effect at 1 GHz is sufficiently large at 40 to 50 dB, but the fiber diameter required for regularly arranging the conductive fibers so as to prevent the electromagnetic wave leakage is too large at 35 μm, so that the fibers cannot be seen. It was not suitable for display use (hereinafter referred to as visibility). Also, JP-A-62-57297,
Similarly, in the case of an electromagnetic wave shielding material in which a conductive resin containing a metal powder or the like disclosed in JP-A-2-52499 is directly printed on a transparent substrate, the line width is set to 100 due to the limit of printing accuracy.
It was not suitable because the visibility was around μm. Further, in a shielding material in which a transparent resin layer is formed on a transparent substrate such as polycarbonate having a thickness of about 2 mm described in JP-A-5-283889 and a copper mesh pattern is formed thereon by electroless plating, In order to secure the adhesion of electroless plating, it is necessary to roughen the surface of the transparent substrate. Generally, a highly toxic oxidizing agent such as chromic acid or permanganic acid must be used as the roughening means. With this method, it is difficult to perform satisfactory roughening with a resin other than ABS. Even if electromagnetic shielding and transparency can be achieved by this method,
It is difficult to reduce the thickness of the transparent substrate, and it is not suitable for forming a film. If the transparent substrate is thick, it cannot be brought into close contact with the display, so that leakage of electromagnetic waves from the transparent substrate increases. Further, in terms of manufacturing, there is also a drawback that the shield material cannot be made into a scroll or the like, so that it becomes bulky, and is not suitable for automation, so that the manufacturing cost increases. Regarding the shielding property of electromagnetic waves generated from the entire display, in addition to the electromagnetic wave shielding function of 30 dB or more at 1 GHz, infrared rays of 900 to 1,100 nm generated from the front of the display adversely affect other VTR devices and the like. Need to be shielded. Not only good visible light transmittance and high visible light transmittance, but also adhesiveness that can be adhered closely to the display surface to prevent leakage of electromagnetic waves, and the property of not being able to visually confirm the presence of shielding material Is also required. As for the adhesiveness, it is necessary to easily adhere to glass or a general-purpose polymer plate at a relatively low temperature and have good adhesiveness over a long period of time. However, there has not been obtained any material which simultaneously sufficiently satisfies such characteristics as electromagnetic wave shielding, infrared shielding, transparency / invisibility, and adhesiveness.
In view of the above, an object of the present invention is to provide an adhesive film having electromagnetic wave shielding properties and infrared ray shielding properties, transparency and invisibility, and good adhesive properties, a display using the same, and an electromagnetic wave shield.

[0005]

According to the first aspect of the present invention, an electromagnetic wave shielding property, an infrared ray shielding property, a transparency,
In order to provide an adhesive film having invisibility and good adhesive properties, (1) a line forming a geometric figure in a constituent material in which a geometric figure formed of a conductive material is provided on the surface of a plastic base material A width of 40 μm or less, a line interval of 200 μm or more, and a line thickness of 40 μm or less, a part or the whole of the base material including the geometrical figure is coated with an adhesive, and (2) an adhesive for covering the geometrical figure When the plastic substrate or the plastic substrate is laminated with the conductive material via the adhesive layer, the difference in refractive index between the adhesive layer and the adhesive covering the geometrical figure is set to 0.
(3) Infrared absorptance in the range of 900 to 1 and 100 nm is 50% or more on average. The invention according to claim 2 is to make the plastic substrate a polyethylene terephthalate film in order to provide an adhesive film having transparency, inexpensiveness, good heat resistance, and excellent electromagnetic wave shielding properties and infrared shielding properties with excellent handleability. is there. The third aspect of the present invention provides an adhesive film that is excellent in processability and adhesion, is inexpensive, and has electromagnetic wave shielding properties and infrared ray shielding properties.
A metal foil of copper, aluminum, or nickel having a thickness of 0 μm is used, and a bonding surface with a plastic substrate or an adhesive layer is roughened. According to the fourth aspect of the present invention, in order to provide an adhesive film having a small fading property and a high electromagnetic wave shielding property and an infrared shielding property with high contrast, at least the surface thereof is subjected to blackening treatment using copper as a conductive material. It is characterized by the following. In order to provide an adhesive film having excellent electromagnetic wave shielding properties and infrared shielding properties excellent in processability, a geometric pattern formed of a conductive material on a surface of a plastic substrate is subjected to a chemical etching process. Characterized by the following. The invention according to claim 6 is
In order to provide an adhesive film having an electromagnetic wave shielding property and an infrared ray shielding property excellent in a magnetic field shielding property, a conductive material is a paramagnetic metal. According to a seventh aspect of the present invention, the adhesive film having the electromagnetic wave shielding property and the infrared shielding property is used for a display. The invention according to claim 8 is to provide the adhesive film having the electromagnetic wave shielding property and the infrared shielding property in a window or a housing except for the inside of a measuring device, a measuring device or a manufacturing device for generating an electromagnetic wave, and the electromagnetic wave is provided. This is an electromagnetic wave shielding structure provided in a housing, particularly a portion such as a window where transparency is required, in order to shield the device and equipment from electromagnetic waves.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The plastic substrate referred to in the present invention includes polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene, polystyrene and EVA, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, polysulfone, A film made of a plastic such as polyethersulfone, polycarbonate, polyamide, polyimide, or acrylic resin and having a total visible light transmittance of 70% or more. These can be used as a single layer, or may be used as a multilayer film combining two or more layers. Of these, polyethylene terephthalate is most suitable in terms of transparency, heat resistance, ease of handling, and price. The thickness of the substrate is preferably from 5 to 200 μm. If it is less than 5 μm, the handleability becomes poor, and if it exceeds 200 μm, the transmittance of visible light decreases. 10-100 μm is more preferable, and 25
~ 50 µm is most preferred.

As the conductive material of the present invention, it is possible to use an alloy of one or more of metals such as copper, aluminum, nickel, iron, gold, silver, stainless steel, tungsten, chromium and titanium. it can. Copper, aluminum or nickel is suitable from the viewpoints of conductivity, ease of circuit processing, and price, and a metal foil having a thickness of 3 to 40 μm is preferable. If the thickness exceeds 40 μm, it is difficult to form a line width or the viewing angle becomes narrow. If the thickness is less than 3 μm, the surface resistance increases and the electromagnetic wave shielding effect is poor. It is preferable that the conductive material be copper and at least the surface thereof has been subjected to blackening treatment because the contrast is high. Further, it is possible to prevent the conductive material from being oxidized with time and discolored. The blackening process is
It may be performed before and after the formation of the geometrical figure, but after the formation, it can be performed by using a method used in the field of printed wiring boards. For example, sodium chlorite (31
g / l), sodium hydroxide (15 g / l), and trisodium phosphate (12 g / l) in an aqueous solution at 95 ° C for 2 minutes. In addition, it is preferable that the conductive material is a paramagnetic metal because of excellent magnetic field shielding properties. The simplest method for bringing the conductive material into close contact with the plastic substrate is to attach the conductive material through an adhesive mainly composed of acrylic or epoxy resin. When it is necessary to reduce the thickness of the conductive layer of the conductive material, one or more of thin film forming techniques such as a vacuum deposition method, a sputtering method, an ion plate method, a chemical vapor deposition method, and an electroless / electroplating method are used. Can be achieved by combining the above methods. Conductive material thickness is 40μ
m or less can be applied, but the smaller the film thickness, the wider the viewing angle of the display, which is preferable as an electromagnetic wave shielding material, and more preferably 18 μm or less.

The geometric figures in the present invention include triangles such as equilateral triangles, isosceles triangles and right triangles, squares, rectangles, and the like.
Rectangles such as rhombus, parallelogram, trapezoid, etc., (positive) hexagons, (positive) octagons, (positive) dodecagons, (positive) n-gons such as (positive) octagons, circles, ellipses, stars The pattern is a combination of molds and the like, and these units can be used alone or in combination of two or more. From the viewpoint of electromagnetic wave shielding, a triangle is most effective. However, from the viewpoint of visible light transmission, if the number of (positive) n-gons is larger, the numerical aperture increases and the visible light transmission increases as the number of (positive) n-gons increases. This is advantageous. As a method of forming such a geometric figure, it is effective from the viewpoint of workability to produce the plastic substrate with the conductive material by a chemical etching process. In addition, there is a method of exposing and developing a photosensitive resin layer disposed on a plastic base material using a mask on which a geometric figure is formed, and forming a geometric figure in combination with electroless plating or electroplating.

The line width of such a geometric figure is 40 μm.
m or less, line spacing is 200 μm or more, line thickness is 4
The range is 0 μm or less. In addition, the line width is 25 μm or less from the viewpoint of invisibility of the geometrical figure, the line interval is 500 μm or more, and the line thickness is 18 μm in terms of visible light transmittance.
The following are more preferred. As the line spacing increases, the visible light transmittance increases, but if this value is too large,
It is preferable that the thickness be 1 mm or less because the electromagnetic wave shielding property is reduced. When the line interval becomes complicated due to a combination of geometric figures and the like, the area is converted into the area of a square based on the repeating unit, and the length of one side is set as the line interval.

Next, the adhesive for covering the geometric figure has a difference in refractive index from the above-mentioned plastic base material of 0.14 or less. In the case where the plastic base material is laminated with the conductive material via the adhesive layer, the difference in the refractive index between the adhesive layer and the adhesive covering the geometric figure is 0.14 or less. This is the refractive index of the plastic substrate and adhesive,
Alternatively, if the refractive index of the adhesive is different from that of the adhesive layer, the visible light transmittance is reduced. If the difference in the refractive index is 0.14 or less, the decrease in the visible light transmittance is small and good. As an adhesive material satisfying such requirements, a plastic base material is polyethylene terephthalate (n = 1.575; refractive index).
In the case of bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetrahydroxyphenylmethane type epoxy resin, novolak type epoxy resin, resorcinol type epoxy resin, polyalcohol / polyglycol type epoxy resin, polyolefin type epoxy resin, alicyclic type And epoxy resins such as halogenated bisphenol (both have a refractive index of 1.55-1.60). Other than the epoxy resin, natural rubber (n = 1.52), polyisoprene (n = 1.521), poly-1,2-butadiene (n = 1.5
0), polyisobutene (n = 1.505 to 1.51), polybutene (n = 1.5125), poly-2-heptyl-1,3-butadiene (n = 1.50), poly-2-t-butyl-1,3-butadiene ( n = 1.506), poly-1,3-butadiene (n
= 1.515), polyoxyethylene (n
= 1.4563), polyoxypropylene (n = 1.4495), polyethers such as polyvinyl ethyl ether (n = 1.454), polyvinyl hexyl ether (n = 1.4591), polyvinyl butyl ether (n = 1.4563), and polyvinyl acetate (n = 1.4665). ), Polyvinyl propionate (n =
Polyesters such as 1.4665) and polyurethane (n = 1.5
1.6), ethyl cellulose (n = 1.479), polyvinyl chloride (n = 1.54 to 1.55), polyacrylonitrile (n = 1.
52), polymethacrylonitrile (n = 1.52), polysulfone (n = 1.633), polysulfide (n = 1.6), phenoxy resin (n = 1.5-1.6) and the like.
These exhibit a suitable visible light transmittance.

On the other hand, when the plastic substrate is an acrylic resin, polyethyl acrylate (n
= 1.4685), polybutyl acrylate (n = 1.466), poly-2-ethylhexyl acrylate (n = 1.463), poly-t-butyl acrylate (n = 1.4638), poly-3
-Ethoxypropyl acrylate (n = 1.465), polyoxycarbonyltetramethacrylate (n = 1.465), polymethyl acrylate (n = 1.472 to 1.480), polyisopropyl methacrylate (n = 1.4728), polydodecyl methacrylate (n = 1.474), Polytetradecyl methacrylate (n = 1.4746), poly-n-propyl methacrylate (n = 1.484), poly-3,3,5-trimethylcyclohexyl methacrylate (n = 1.484), polyethyl methacrylate (n = 1.485), poly- 2-nitro-2-
Methylpropyl methacrylate (n = 1.4868), poly-
1,1-diethylpropyl methacrylate (n = 1.488
9), poly (meth) acrylates such as polymethyl methacrylate (n = 1.4893) can be used. If necessary, two or more of these acrylic polymers may be copolymerized, or two or more of them may be used as a blend.

Furthermore, epoxy acrylate, urethane acrylate, polyether acrylate, polyester acrylate and the like can also be used as the copolymer resin of acrylic resin and other than acrylic resin. In particular, epoxy acrylate and polyether acrylate are excellent from the viewpoint of adhesiveness.
-Hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, allyl alcohol diglycidyl ether, resorcinol diglycidyl ether, diglycidyl adipate, diglycidyl phthalate, polyethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, (Meth) acrylic acid adducts such as glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether and sorbitol tetraglycidyl ether. Epoxy acrylate has a hydroxyl group in the molecule and is therefore effective in improving the adhesiveness. These copolymer resins can be used in combination of two or more as necessary. The polymer used as the main component of the adhesive has a weight average molecular weight of 1,000 or more. Molecular weight 1,0
If it is less than 00, the cohesive strength of the composition is too low, and the adhesion to the adherend is reduced.

Examples of the curing agent for the adhesive include amines such as triethylenetetramine, xylenediamine, N-aminotetramine, diaminodiphenylmethane, phthalic anhydride, maleic anhydride, dodecylsuccinic anhydride, pyromellitic anhydride, and benzophenonetetrahydrate. Acid anhydrides such as carboxylic acids, diaminodiphenylsulfone, tris (dimethylaminomethyl) phenol, polyamide resins, dicyandiamide, and ethylmethylimidazole can be used. These may be used alone or as a mixture of two or more. The addition amount of these crosslinking agents is 0.1 to 50 parts by weight based on 100 parts by weight of the polymer,
Preferably, the amount is selected in the range of 1 to 30 parts by weight.
If this amount is less than 0.1 part by weight, curing will be insufficient, and if it exceeds 50 parts by weight, excessive crosslinking will occur, which may adversely affect the adhesiveness. The resin composition used in the present invention may optionally contain additives such as a diluent, a plasticizer, an antioxidant, a filler and a tackifier. Then, the resin composition of the adhesive is applied to cover a part or the whole of the base material including the geometric figure formed of the conductive material on the surface of the plastic base material, and is subjected to a solvent drying and heat curing step. After that, the adhesive film according to the present invention is obtained. The adhesive film having electromagnetic shielding and infrared shielding properties obtained above can be directly adhered to a display such as a CRT, PDP, liquid crystal, EL, or the like using the adhesive of the adhesive film, or can be used as an acrylic plate or a glass plate. Attached to a board or sheet such as for use in displays. Further, this adhesive film is used in the same manner as described above for a measuring device that generates electromagnetic waves, a window or a casing for looking inside a measuring device or a manufacturing device. Further, it is provided in a window of a building, a window of a car, or the like, which is susceptible to electromagnetic interference due to radio waves or high-voltage lines. In addition, it is preferable to provide an earth line in the geometrical figure drawn with the conductive material.

Next, 900 to 1,100 n of the adhesive film
As a method for making the infrared absorption rate in the region of m equal to or more than 50% on average, metal oxides such as iron oxide, cerium oxide, tin oxide and antimony oxide, indium-tin oxide (ITO), tungsten hexachloride An organic infrared absorbing agent such as tin chloride, cupric sulfide, chromium-cobalt complex salt, thiol-nickel complex or aminium compound, diimonium compound (manufactured by Nippon Kayaku Co., Ltd.), or the like; The composition dispersed in the binder resin can be used by applying it to the adhesive surface of the adhesive film or the back surface of the adhesive film. Among these infrared absorbing compounds, those having the effect of absorbing infrared rays most effectively are organic infrared absorbing agents such as cupric sulfide, ITO, aminium compounds and diimonium compounds. What should be noted here is the particle size of the primary particles of these compounds. If the particle size is too large than the wavelength of infrared rays, the shielding efficiency is improved, but irregular reflection occurs on the particle surface and haze is increased, so that transparency is reduced. On the other hand, if the particle size is too short compared to the wavelength of infrared rays, the shielding effect will be reduced. The preferred particle size is 0.01 to 5 μm, more preferably 0.1 to 3 μm. These infrared absorbing materials are epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin,
Polyene prepolymers such as polyisoprene, poly-1,2-butadiene, polyisobutene, diene resins such as polybutene, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, etc., polyvinyl acetate, polyvinyl It is uniformly dispersed in a binder resin such as a polyester resin such as propionate and a polyolefin resin such as polyethylene, polypropylene, polystyrene and EVA. The optimal amount of the compound is 0.01 to 100 parts by weight of the binder resin in the infrared absorbing material.
The amount is 10 parts by weight, but 0.1 to 5 parts by weight is more preferable. Less than 0.01 parts by weight has little infrared shielding effect,
If it exceeds 10 parts by weight, transparency is impaired. These compositions are applied in a thickness of 0.1 to 10 μm on the adhesive surface or the back surface of the adhesive film. The applied composition containing the infrared absorbing compound may be cured using heat or UV. On the other hand, an infrared absorbing compound can be used by directly mixing it with the above-mentioned adhesive composition. In this case, the amount of the polymer 1 as the main component of the adhesive was
0.1 to 5 parts by weight is optimal from the viewpoint of the effect and the transparency with respect to 00 parts by weight.

According to the present invention, the portion of the plastic substrate from which the conductive material has been removed is intended to have irregularities intentionally to improve the adhesion or to transfer the back shape of the conductive material. Light is scattered on the surface and transparency is impaired, but if a resin with a refractive index close to that of the plastic substrate is smoothly applied to the uneven surface, irregular reflection is suppressed to a minimum and transparency is exhibited. It is considered to be. Furthermore, geometric figures formed of conductive materials on plastic substrates,
The line width is so small that it cannot be seen with the naked eye. In addition, the pitch is sufficiently large, and it is considered that apparent transparency is exhibited. On the other hand, compared to the wavelength of the electromagnetic wave to be shielded,
It is considered that the pitch of the geometrical figure is sufficiently small to exhibit excellent shielding properties.

[0016]

EXAMPLES Next, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. <Adhesive Film Production Example 1> A transparent PET film (refractive index n = 1.57) having a thickness of 50 μm as a plastic substrate
5), and an epoxy-based adhesive sheet (Nikaflex SAF, manufactured by Nickan Industry Co., Ltd., n
(1.58, thickness 20 μm), an electroconductive copper foil having a thickness of 18 μm as a conductive material was placed at 180 ° C., 30 kgf /
Heat lamination was performed under the condition of cm ² to adhere. Through a photolithography process (resist film pasting-exposure-development-chemical etching-resist film peeling) on the obtained PET film with copper foil, a copper grid pattern having a line width of 25 μm and a line interval of 500 μm was formed on the PET film, Material 1 was obtained. The visible light transmittance of this constituent material 1 was 20% or less. An adhesive to be described later is applied to the surface on which the geometrical figure of the constituent material 1 is provided with a dry coating thickness of about 40 μm.
m and dried to obtain an adhesive film 1 having electromagnetic wave shielding properties and transparency. This adhesive film 1
An infrared shielding layer described later was formed on the surface opposite to the surface on which the adhesive was applied so that the dry coating thickness was 5 μm. Then, the adhesive film was commercialized using a roll laminator using a commercially available acrylic plate (Como Glass; Kuraray Co., Ltd., thickness 3).
mm) under a condition of 110 ° C. and 20 kg / cm ² so that the surface on which the adhesive is applied is in contact with the surface.

<Adhesive Film Production Example 2> An acrylic adhesive sheet (Pilalux LF-0200; manufactured by DuPont, n = 1.47) was formed on a transparent PET film having a thickness of 25 μm.
An aluminum foil having a thickness of 25 μm was adhered to the aluminum foil through a thickness of 20 μm. An aluminum lattice pattern having a line width of 25 μm and a line interval of 250 μm was formed on the PET film with the aluminum foil through the same photolithography process as in Production Example 1 on the PET film. Its visible light transmittance was 20% or less. An adhesive described later was applied to the surface of the constituent material 2 on which the geometrical figure was formed so that a dry coating thickness was about 30 μm, and dried to obtain an adhesive film 2 having electromagnetic wave shielding properties and transparency. An infrared shielding layer described later was formed on the surface of the adhesive film 2 opposite to the surface on which the adhesive was applied, so that the dry coating thickness was 1 μm. Then, the adhesive film was placed on a commercially available acrylic plate such that the surface on which the adhesive was applied was in contact with 110 ° C., 30 kgf / cm ² ,
It was thermocompression bonded using a hot press under a condition of 30 minutes.

<Adhesive Film Production Example 3> A line width of 12 μm was formed on a 50 μm-thick PET film by forming electroless nickel plating in a lattice pattern using a mask layer.
A nickel lattice pattern having a thickness of 2 μm and a line spacing of 500 μm was prepared on a PET film. Its visible light transmittance was 20% or less. Dry the adhesive on the surface of the film where the geometrical figures are formed.
It was applied so as to have a thickness of 0 μm. An infrared shielding layer described below was formed on the surface of the adhesive film 3 opposite to the surface on which the adhesive was applied, so that the dry coating thickness was 3 μm.
Thereafter, the adhesive film was heat-pressed at 110 ° C. and 20 kgf / cm ² by using a roll laminator such that the surface of the commercially available acrylic plate to which the adhesive was applied was in contact.

<Adhesive Composition 1> 100 parts by weight of TBA-HME (manufactured by Hitachi Chemical Co., Ltd .; high molecular weight epoxy resin, Mw = 300,000) YD-8125 (manufactured by Toto Kasei Co., Ltd .; bisphenol A type epoxy) Resin) 25 parts by weight IPDI (manufactured by Hitachi Chemical Co., Ltd .; mask isocyanate) 12.5 parts by weight 2-ethyl-4-methylimidazole 0.3 part by weight MEK 330 parts by weight Cyclohexanone 15 parts by weight Solvent drying of this composition The later refractive index was 1.57.

<Adhesive Composition 2> 100 parts by weight of YP-30 (manufactured by Toto Kasei Co., Ltd .; phenoxy resin, Mw = 60,000) YD-8125 (manufactured by Toto Kasei Co., Ltd .; bisphenol A type epoxy resin) 10 Parts by weight IPDI (manufactured by Hitachi Chemical Co., Ltd .; mask isocyanate) 5 parts by weight 2-ethyl-4-methylimidazole 0.3 parts by weight MEK 285 parts by weight cyclohexanone 5 parts by weight The refractive index of the composition after drying with a solvent is as follows. 1.55.

<Adhesive Composition 3> HTR-600LB (manufactured by Teikoku Chemical Industry Co., Ltd .; polyacrylate, Mw = 700,000) 100 parts by weight Coronate L (manufactured by Nippon Polyurethane Co., Ltd .; trifunctional isocyanate) 4 0.5 parts by weight Dibutyltin dilaurate 0.4 parts by weight Toluene 450 parts by weight Ethyl acetate 10 parts by weight The refractive index of the composition after drying with a solvent was 1.47.

<Composition 1 for Infrared Shielding Layer> YD-8125 (manufactured by Toto Kasei Co., Ltd .; bisphenol A epoxy resin) 100 parts by weight Copper sulfide (manufactured by Wako Pure Chemical Industries, Ltd.) 4 parts by weight 2-ethyl-4-methylimidazole 0.5 parts by weight Dicyandiamide 5 parts by weight MEK 200 parts by weight Ethylene glycol monomethyl ether 20 parts by weight Application using an applicator at room temperature, It was cured by heating at 90 ° C. for 30 minutes.

<Composition 2 for Infrared Shielding Layer> HTR-280 (manufactured by Teikoku Chemical Industry Co., Ltd .; polyacrylate copolymer, Mw = about 700,000) 100 parts by weight UFP-HX (Sumitomo Metal Mining Co., Ltd.) Co., Ltd .; ITO, average particle size 0.1 μm) 0.5 parts by weight Coronate L 5 parts by weight Dibutyltin dilaurate 0.4 parts by weight Toluene 450 parts by weight Ethyl acetate 10 parts by weight Using an applicator at room temperature, It was cured by heating at 90 ° C. for 20 minutes.

<Composition 3 for Infrared Shielding Layer> 1 part of cupric sulfide (manufactured by Wako Pure Chemical Industries, Ltd .; pulverized to an average particle size of 0.5 μm with a Henschel mixer)

Example 1 A shielding plate obtained by the procedure of Adhesive Film Production Example 1 using the adhesive composition 1 and the composition 1 forming an infrared shielding layer was used as Example 1. (Example 2) A shielding plate obtained by the procedure of Adhesive Film Production Example 2 using Adhesive Composition 2 and Composition 1 forming an infrared shielding layer was used as Example 2. (Example 3) A shielding plate obtained by the procedure of Adhesive Film Production Example 3 using Adhesive Composition 3 and Composition 1 forming an infrared shielding layer was used as Example 3. Example 4 Example 1 except that the line width was changed from 25 μm to 35 μm, and the composition for the infrared shielding layer was changed to 2.
The shielding plate obtained in the same manner as in Example 4 was used as Example 4. (Example 5) Example 2 was repeated except that the line width was changed from 25 µm to 12 µm, and the composition constituting the infrared shielding layer was changed to 2.
The shielding plate obtained in the same manner as in Example 5 was used as Example 5. Example 6 A shielding plate obtained in the same manner as in Example 3 except that the line interval was changed from 500 μm to 800 μm and the composition constituting the infrared shielding layer was changed to Example 6 was used as Example 6. (Example 7) A shielding plate obtained in the same manner as in Example 1 except that the line interval was changed from 500 µm to 250 µm was used as Example 7. Example 8 A shielding plate obtained in the same manner as in Example 2 except that the line thickness was changed from 25 μm to 35 μm was used as Example 8. (Example 9) A shielding plate obtained in the same manner as in Example 1 except that the blackened copper was used as the conductive material and the composition for the infrared shielding layer was changed to Example 2 was used as Example 9. (Example 10) The same conditions as in Example 1 were used except that a regular triangular repetitive pattern was formed instead of the lattice pattern formed in Example 1, and the composition constituting the infrared shielding layer was changed to 2. (Example 11) A regular hexagonal repeating pattern was prepared in place of the lattice pattern formed in Example 1, and 1 part by weight of the composition 3 constituting the infrared shielding layer was directly added to 100 parts by weight of the adhesive. Was dispersed. (Example 12) Instead of the lattice pattern formed in Example 1, a regular pattern composed of regular octagons and squares was prepared, and 1 part by weight of the composition 3 constituting the infrared shielding layer was added to 100 parts by weight of the adhesive. Dispersed directly in the adhesive.

(Comparative Example 1) In place of copper foil, ITO deposited PET in which an ITO film was entirely deposited at 2,000Å was used.
The adhesive composition 1 was directly applied without forming a pattern. Thereafter, a shielding plate obtained in the same manner as in Example 1 without forming an infrared shielding layer was used as Comparative Example 1. (Comparative Example 2) As in Comparative Example 1, instead of ITO, the adhesive composition 2 was directly applied without forming a pattern while aluminum deposition was performed on the entire surface. Thereafter, a shielding plate obtained in the same manner as in Comparative Example 1 was used as Comparative Example 2. (Comparative Example 3) A shielding plate obtained in the same manner as in Example 1 except that the line width was changed from 25 µm to 50 µm and an infrared shielding layer was not formed was used as Comparative Example 3. (Comparative Example 4) A shielding plate obtained in the same manner as in Example 2 except that the line interval was changed from 250 µm to 150 µm and the infrared shielding layer was not formed was used as Comparative Example 4. (Comparative Example 5) A shielding plate obtained in the same manner as in Example 2 except that the line thickness was changed from 25 µm to 70 µm and an infrared shielding layer was not formed was used as Comparative Example 5. Comparative Example 6 A phenol-formaldehyde resin (Mw = 50,000, n = 1.73) was used as an adhesive, and all conditions were the same as in Example 1 except that no infrared shielding layer was formed. The shielding plate was Comparative Example 6. (Comparative Example 7) Polydimethylsiloxane (M
(w = 45,000, n = 1.43), and a shielding plate obtained in the same manner as in Example 3 except that no infrared shielding layer was formed was used as Comparative Example 7. Comparative Example 8 Polyvinylidene fluoride (Mw = 120,000, n = 1.42) was used as an adhesive, and all conditions were the same as in Example 3 except that no infrared shielding layer was formed. The shielding plate was Comparative Example 8. (Comparative Example 9) Shielding obtained in the same manner as in Example 1 except that a filled polyethylene film (visible light transmittance: 20% or less) was used as a plastic substrate, and no infrared shielding layer was formed. The plate was Comparative Example 9. (Comparative Example 10) A shielding plate obtained in the same manner as in Example 1 except that the coating thickness of the composition 2 forming the infrared shielding layer was changed from 5 µm to 0.05 µm using the adhesive composition 2 and Comparative Example 11 did.

The shielding plate obtained as described above has an infrared shielding factor, an electromagnetic wave shielding property, a visible light transmittance, a non-visibility,
The adhesive property and the fading property before and after the heat treatment were measured. The results are shown in Tables 1 and 2.

The infrared shielding factor was measured by a spectrophotometer (manufactured by
900-1 by using U-3410 manufactured by Hitachi, Ltd.
The average value of the infrared absorptivity in the region of 100 nm was used. The electromagnetic wave shielding property was measured by inserting a sample between flanges of a coaxial waveguide converter (manufactured by Japan High Frequency Co., Ltd., TWC-S-024) and using a spectroanalyzer (YHP, 8510).
(B vector network analyzer) at a frequency of 1 GHz. The measurement of the visible light transmittance was performed using a double beam spectrophotometer (manufactured by Hitachi, Ltd., 200-10).
The average value of the transmittance at 400 to 800 nm was used. The non-visibility is evaluated by visually observing the adhesive film stuck on the acrylic plate from a place 0.5 m away, and evaluating whether or not the geometrical figure formed of the conductive material can be recognized. NG, and those that can be recognized. The adhesive force was measured using a tensile tester (manufactured by Toyo Baldwin Co., Ltd., Tensilon UTM-4-100) at a width of 10 mm, a direction of 90 °, and a peeling speed of 50 mm / min. The refractive index was measured at 25 ° C. using a refractometer (Abago Refractometer, manufactured by Atago Optical Machine Works).

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

As is clear from the examples, the adhesive film having an electromagnetic wave shielding property and an infrared ray shielding property obtained by the present invention has an excellent infrared ray shielding property and can be used in close contact with an adherend. There is no leakage and the shielding function is particularly good. In addition, optical properties such as visible light transmittance and invisibility are good, and there is little change in adhesive properties at high temperature over a long period of time, and good adhesive films can be provided. Further, by making the transparent plastic film substrate according to claim 2 a polyethylene terephthalate film, an adhesive film having excellent electromagnetic shielding properties and infrared shielding properties that is excellent in transparency, heat resistance, inexpensive and easy to handle. Can be provided. The thickness of the conductive material according to claim 3 is 3 to 40 μm.
By using a copper, aluminum or nickel metal foil with a rough surface for bonding to a transparent plastic substrate, it provides an inexpensive adhesive film with excellent workability and low cost of electromagnetic wave shielding and infrared shielding. can do. By providing the conductive material according to claim 4 as copper and at least the surface thereof being subjected to blackening treatment, an adhesive film having a small fading property, a high contrast, an electromagnetic wave shielding property and an infrared shielding property is provided. be able to. By forming the geometric pattern on the transparent plastic substrate according to claim 5 by a chemical etching process, it is possible to provide an adhesive film having excellent electromagnetic wave shielding properties and infrared shielding properties with excellent workability. By making the conductive material according to claim 6 a paramagnetic metal, it is possible to provide an adhesive film having an excellent electromagnetic field shielding property and an excellent infrared shielding property. The EMI shielding property is excellent by using the adhesive film having the electromagnetic wave shielding property and the infrared ray shielding property according to claim 7 for a display or an electromagnetic wave shielding structure.
Since the visible light transmittance is large, the display can be viewed under almost the same conditions as in a normal state without increasing the brightness of the display, and video (VTR) by infrared rays, C
Malfunction of an electronic device having a remote control function such as D or radio can be prevented, and a geometric figure drawn with a conductive material cannot be visually recognized, so that it can be viewed without a sense of incongruity.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Minoru Tosaka 1500 Ogawa, Oji, Shimodate-shi, Ibaraki Pref.Hitachi Kasei Kogyo Co., Ltd. Goshonomiya Factory Co., Ltd.

Claims (8)

[Claims] (1) In a constituent material in which a geometric figure formed of a conductive material is provided on a surface of a plastic substrate,
The line width of the geometric figure is 40 μm or less, the line interval is 200 μm or more, and the line thickness is 40 μm or less. A part or the whole of the base material including the geometric figure is coated with an adhesive, and The difference in refractive index between the adhesive covering the geometrical figure and the plastic substrate, or between the adhesive layer and the adhesive covering the geometrical figure when the plastic substrate is laminated with a conductive material via the adhesive layer 0.14
(3) An adhesive film having electromagnetic wave shielding properties and infrared ray shielding properties, characterized in that the infrared absorption in the region of 900 to 1,100 nm is 50% or more on average. 2. The adhesive film according to claim 1, wherein the plastic substrate is a polyethylene terephthalate film. 3. The electromagnetic wave shielding property according to claim 1, wherein the conductive material is a metal foil of copper, aluminum or nickel having a thickness of 3 to 40 μm, and a bonding surface to the plastic substrate is rough. And an adhesive film having infrared shielding properties. 4. The adhesive film having electromagnetic shielding properties and infrared shielding properties according to claim 3, wherein the conductive material is copper, and at least the surface thereof is blackened. 5. The method according to claim 1, wherein the geometrical figure formed of the conductive material on the surface of the plastic substrate is formed by a chemical etching process. Adhesive film with electromagnetic shielding and infrared shielding properties. 6. The method according to claim 1, wherein the conductive material is a paramagnetic metal.
The adhesive film according to claim 2, wherein the adhesive film has an electromagnetic wave shielding property and an infrared ray shielding property. 7. A display using the adhesive film having an electromagnetic shielding property and an infrared shielding property according to claim 1. 8. An electromagnetic wave shielding structure provided with the adhesive film having an electromagnetic wave shielding property and an infrared ray shielding property according to claim 1.