JPH11340682A - Electromagnetic shielding adhesive film, electromagnetic shielding object using the same, and display formed of both materials - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shielding adhesive film, has a good shielding property with respect to electromagnetic waves generated from the display front and a good infrared shielding property, transparency, non-visibility and adhesive nature, and electromagnetic shielding object using the adhesive film, and display formed of the film and the object which. SOLUTION: The electromagnetic shielding adhesive film has a geometric figure 2 drawn with a conductive metal on a plastic film 3 with a conductive metal having an adhesive layer 1, the geometric figure has a line width of 40 μm or less, line spacing of 100 μm or more, line thickness of 40 μm or less and line intersection swell ratio of less than 400%, and this film is used for an electromagnetic shield structure and display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding 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, an EL and the like, and an electromagnetic wave using the film. It relates to a shielding structure, a display.

[0002]

2. Description of the Related Art In recent years, with the increase in the use of various types of electrical equipment and electronic equipment, electromagnetic noise interference has been increasing steadily. Noise can be broadly divided into conducted noise and radiated noise.
There is a method using a noise filter or the like. On the other hand, as a countermeasure against radiation noise, it is necessary to electromagnetically insulate the space, so make the housing a metal body or a highly conductive body, insert a metal plate between circuit boards, Is wrapped with metal foil. With these methods, an electromagnetic wave shielding effect of a circuit or a power supply block can be expected, but it cannot be applied to an electromagnetic wave shielding generated from the front of a display such as a CRT or PDP because it is 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) or 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).
JP-A-62-5) in which a conductive resin containing metal powder and the like is printed directly on a transparent substrate.
7297, JP-A-2-52499),
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 JP-A-5-283889). ), A method of forming a geometric figure on a surface of a transparent plastic substrate with a conductive material (see Japanese Patent Application Laid-Open No. H10-41682) 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. 100 ° to 2,000 °), the surface resistance of the conductive layer becomes too large, so that the shielding effect of 30 dB or more required at 30 MHz to 1 GHz exceeds 20 dB.
The following were insufficient. In an electromagnetic wave shielding material in which a good conductive fiber is embedded in a transparent base material (JP-A-5-327274 and JP-A-5-269912), 30 MHz is used.
Although the electromagnetic wave shielding effect of １1 GHz is 40 to 50 dB, the fiber diameter required for regularly arranging the conductive fibers so as not to leak electromagnetic waves is 35 μm, which is too large, so that the fibers are visible (hereinafter referred to as visibility). In contrast to the visible light transmittance of 60% or more, it was insufficient at 55% or less, and was not suitable for display use. Also, 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-62-57297 and JP-A-2-52499 is directly printed on a transparent substrate, the line accuracy is similarly limited due to the limitation of printing accuracy. The width was about 100 μm, which was not suitable because visibility was developed. JP-A-10-41
In the method of forming a geometrical figure with a conductive material on the surface of a transparent plastic substrate described in Japanese Patent Application Publication No. 682, lines of a conductive material are formed according to the geometrical figure as shown in FIGS. The area occupied by the line of the geometric figure at the intersection of the lines increases (the blister rate is large), and when the line width is reduced or the line interval is reduced, the intersection of the lines is conspicuous and the blister rate is reduced. Due to the large size, the visible light transmittance could not be increased. Further, the thickness described in JP-A-5-283889 is 2 mm.
In a shielding material in which a transparent resin layer is formed on a transparent substrate such as polycarbonate and a copper mesh pattern is formed thereon by an electroless plating method, in order to secure the adhesion of the electroless plating, The surface needs to be roughened. 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 wave shielding properties and transparency can be achieved by this method, it is difficult to reduce the thickness of the transparent substrate, and it is not suitable as a method for forming a film. Furthermore, if the transparent substrate is thick, it cannot be brought into close contact with the display, so that leakage of electromagnetic waves therefrom increases. In addition, 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 the electromagnetic wave generated from the front of the display, it is necessary to have an electromagnetic wave shielding function of 30 dB or more at 30 MHz to 1 GHz.
900-1,100 nm generated from the front of the display
Because infrared rays have a bad effect on other VTR equipment,
This needs to be shielded. In addition to this, the visible light transmittance is required to be 60% or more. Not only the visible light transmittance is large, but also the adhesiveness and the presence of a shielding material that is closely adhered to the display surface to prevent leakage of electromagnetic waves. Non-visibility, a property that cannot be confirmed with the naked eye, 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, no satisfactory adhesive film has been obtained so far that simultaneously satisfies the characteristics such as electromagnetic wave shielding property, infrared ray shielding property, transparency / invisibility, and adhesiveness. In view of the above, the present invention provides electromagnetic wave shielding, infrared shielding, and transparency.
An object of the present invention is to obtain an electromagnetic wave shielding adhesive film having invisibility and good adhesive properties.

[0005]

The invention according to claim 1 of the present invention is intended to provide an electromagnetic wave shielding adhesive film having excellent electromagnetic wave shielding property, invisibility, transparency, and easy adhesion. In a plastic film with a conductive metal having an adhesive layer, a geometric pattern drawn with a conductive metal has a line width of 40 μm or less and a line interval of 100 μm.
μm or more, the line thickness is 40 μm or less, and the swelling ratio at the line intersection is within 400%. here,
The blistering ratio is a ratio of a portion where a line is larger than an originally desired line width. For example, in the case of FIG. 4, when the area of the black portion is S1 and the area of the hatched portion is S2, the blister rate (%) is defined as (S1 + S2) × 100 / S1. In the case of FIG. 5, when the area of the black portion is S3 and the area of the hatched portion is S4, the blister rate (%) is defined as (S3 + S4) × 100 / S3. In the case of FIG. 6, when the area of the black portion is S5 and the area of the hatched portion is S6, the swelling rate (%) is defined as (S5 + S6) × 100 / S5. The swelling rate of such a geometric figure drawn with a conductive metal is set to within 400%. When the blistering ratio exceeds 400%, the aperture ratio becomes small, the visible light transmittance becomes less than 60%, and the blistering ratio becomes 40%.
By setting it within 0%, the visible light transmittance can be maintained at 60% or more. From the viewpoint of invisibility, the blistering rate is 200.
% Is more preferable. The invention according to claim 2 of the present invention uses a chemical etching method to form a geometrical pattern on a conductive metal in order to provide an electromagnetic shielding shielding adhesive film which is inexpensive and excellent in processability, mass productivity, and electromagnetic shielding properties. It is to draw. The third aspect of the present invention is to form a geometric figure drawn with a conductive metal by a chemical etching method by narrowing a line width at a line intersection portion in a line width forming a geometric figure. It is a characteristic adhesive film for electromagnetic wave shielding. In the electromagnetic wave shielding adhesive film obtained by this method, the width of the intersection of the lines is made narrower than the original line width, so that when forming a geometric figure by the etching method, the line width becomes the original line width. , The value of the swelling ratio can be reduced. According to a fourth aspect of the present invention, there is provided an electromagnetic wave shielding adhesive film characterized in that a figure is formed at a line intersection of a conductive metal at a line width forming a geometric figure. The electromagnetic wave shielding adhesive film obtained by this method can form a graphic at an intersection where a large area is occupied even if the swelling ratio is relatively high, and light can be transmitted from that part, so that the transparency can be enhanced. The invention according to claim 5 of the present invention is to provide an electromagnetic wave shielding adhesive film that is inexpensive, has good transparency and good heat resistance, and has excellent handleability.
The plastic film is a polyethylene terephthalate film or a polycarbonate film. The invention according to claim 6 of the present invention uses a paramagnetic metal as the conductive metal in order to provide an electromagnetic wave shielding adhesive film having excellent magnetic field shielding properties. The invention according to claim 7 of the present invention is excellent in workability and adhesion, invisibility, and provides an inexpensive electromagnetic wave shielding adhesive film, and the thickness of the conductive metal is copper, aluminum or 1 to 40 μm. A nickel metal foil is used. According to an eighth aspect of the present invention, in order to provide an electromagnetic wave shielding adhesive film having low fading and high contrast, the conductive metal is copper and at least the surface thereof is blackened. The ninth aspect of the present invention provides an adhesive layer having an electromagnetic wave shielding property, transparency and infrared ray shielding property, in which an infrared ray absorbing agent is contained in the adhesive layer. The invention according to claim 10 of the present invention provides an electromagnetic wave shielding structure in which an electromagnetic wave shielding adhesive film is attached to at least one surface of a plastic plate to provide an electromagnetic wave shielding substrate having electromagnetic wave shielding properties and transparency. Things. The invention according to claim 11 of the present invention is
In order to provide an electromagnetic wave shielding substrate having electromagnetic wave shielding properties, transparency and infrared ray shielding properties, an electromagnetic wave shielding adhesive film is attached to at least one surface of a plastic plate, and an adhesive or an adhesive film having infrared ray shielding properties is provided on the other surface. An electromagnetic wave shielding structure is attached. The invention according to claim 12 of the present invention uses an electromagnetic wave shielding adhesive film having electromagnetic wave shielding properties and transparency for a display. Claim 1 of the present invention
The invention described in Item 3 uses an electromagnetic wave shielding component having electromagnetic wave shielding properties and transparency for a display.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. Examples of the plastic film used in the present invention include 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; and polysulfone. Preferably, the film is made of a plastic such as polyethersulfone, polycarbonate, polyamide, polyimide, or acrylic resin and has a total visible light transmittance of 70% or more and a thickness of 1 mm or less. These can be used as a single layer, or may be used as a multilayer film in which two or more layers are combined. Among the plastic films, a polyethylene terephthalate film or a polycarbonate film is most suitable in terms of transparency, heat resistance, ease of handling, and price. The thickness of the plastic film is more preferably from 5 to 500 μm. If it is less than 5 μm, the handleability becomes poor and the
If it exceeds 00 μm, the transmittance of visible light decreases. 1
More preferably, it is 0 to 200 μm.

[0007] As the conductive metal used in the present invention, copper,
Metals such as aluminum, nickel, iron, gold, silver, stainless steel, tungsten, chromium, and titanium, or alloys of two or more of these metals can be used. Copper, aluminum or nickel is suitable in terms of conductivity, circuit processing easiness and price, and has a thickness of 1 to 4
A metal formed under a vacuum such as a metal foil of 0 μm, a plating metal, and vapor deposition is used. When the thickness exceeds 40 μm,
It is difficult to form a fine line width, and the viewing angle becomes narrow. If the thickness is less than 1 μm, the surface resistance tends to be large, and the electromagnetic wave shielding effect tends to be poor. On the other hand, when iron, nickel, or cobalt, which is a paramagnetic metal, is used as the conductive metal, it is possible to remarkably improve not only the electric field but also the magnetic field shielding property.

It is preferable that the conductive metal is copper and at least the surface thereof has been subjected to a blackening treatment because the contrast is high. Further, it is possible to prevent the conductive metal from being oxidized with time and discolored. The blackening process may be performed before and after the formation of the geometrical figure. However, after the formation, the blackening process 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), trisodium phosphate (12 g / l)
g / l) in an aqueous solution at 95 ° C for 2 minutes. The simplest method for bringing the conductive metal into close contact with the plastic film is to attach the conductive metal via an adhesive layer mainly composed of acrylic or epoxy resin. When it is necessary to reduce the thickness of the conductive layer of the conductive metal, 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. This can be achieved by a combination of methods. The thickness of the conductive metal is set to 40 μm or less, and the smaller the thickness is, the wider the viewing angle of the display becomes, which is preferable as an electromagnetic wave shielding material.

The geometric figures in the present invention include triangles such as equilateral triangles, isosceles triangles and right triangles, squares, rectangles, and the like.
Rectangle such as rhombus, parallelogram, trapezoid, etc., (positive) hexagon, (positive) octagon, (positive) n-sided polygon such as dodecagon, (positive) octagon, etc. (n is a positive integer) , A circle, an ellipse, a star, 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 transmittance, the aperture ratio increases as the number of (positive) n-gons increases with the same line width. From the viewpoint, the aperture ratio needs to be 50% or more, and more preferably 60% or more. The aperture ratio is a percentage of the ratio of the area obtained by subtracting the area of the conductive metal of the geometric figure drawn with the conductive metal from the effective area to the effective area of the electromagnetic wave shielding adhesive film. When the area of the display screen is defined as the effective area of the electromagnetic wave shielding adhesive film, the display screen is a visible ratio.

As a method of forming such a geometric figure, it is effective from the viewpoint of circuit processing accuracy and circuit processing efficiency to manufacture a conductive metal-coated plastic film having the above-mentioned adhesive layer by a microlithographic method. It is.
This microlithography includes photolithography,
There are an X-ray lithography method, an electron beam lithography method, an ion beam lithography method and the like, and in addition thereto, a screen printing method, an intaglio printing method, a relief printing method and the like are also included. Among these, the photolithographic method is the most efficient in terms of its simplicity and mass productivity. Among them, the chemical etching method is most preferable in terms of its simplicity, economy, circuit processing accuracy, and the like. Among the photolithographic methods, in addition to the chemical etching method, it is also possible to form a geometric figure by a method using electroless plating or electroplating, or a combination of electroless plating or electroplating and the chemical etching method.

The line width of such a geometric figure is 40 μm.
m or less, line spacing is 100 μm or more, line thickness is 4
The range is 0 μm or less. Further, from the viewpoint of invisibility of the geometric figure, the line width is more preferably 25 μm or less, and the line interval is more preferably 120 μm or more and the line thickness is 18 μm or less from the viewpoint of visible light transmittance. The line width is set to 40 μm or less, preferably 25 μm or less. If the line width is too small, the surface resistance becomes too large and the shielding effect is inferior. The line thickness is set to 40 μm or less. If the line thickness is too small, the surface resistance becomes too large and the shielding effect is deteriorated. The aperture ratio increases as the line interval increases, and the visible light transmittance increases. When used on the front of the display, the aperture ratio is 5
0% or more is necessary, but 60% or more is more preferable. If the line interval is too large, the electromagnetic wave shielding property is reduced. Therefore, the line interval is preferably 1 mm or less. When the line interval is complicated by a combination of geometric figures and the like, the area is converted into a square area on the basis of a repeating unit, and the length of one side is set as the line interval.

In such a geometrical figure drawn with a conductive metal, the bulging rate at the line intersection is likely to be large, and especially when the line width and the line interval are small, the intersection of the lines is conspicuous and the bulging rate is large. Therefore, it is difficult to improve the visible light transmittance. The blister rate of a line is defined as the ratio of the portion where the line is larger than the originally desired line width. When a geometrical figure drawn with a conductive metal is formed by an etching method, the etching rate differs depending on the method of spraying and dipping the etching solution, etc., so that it is difficult to uniformly etch the whole, and at the intersection of the lines, as shown in FIG. As shown in FIG. 6, the hatched portion remains without being etched. The light transmittance decreases due to the hatched portions left without being etched. If the etching time is lengthened, the hatched portion is etched, but the line is over-etched, the cross section of the line becomes trapezoidal, and the line width as designed cannot be obtained. For example, in the case of FIG.
When the area of the hatched portion is S2, the swelling rate (%) is defined as (S1 + S2) × 100 / S1. In the case of FIG. 5, when the area of the black portion is S3 and the area of the hatched portion is S4, the swelling rate (%) = (S3 + S4) × 100 / S3. In the case of FIG. 6, when the area of the black part is S5 and the area of the hatched part is S6, the swelling rate (%) is defined as (S5 + S6) × 100 / S5. The blister rate of such a geometric figure drawn with a conductive metal is set to be within 400%. When the blistering ratio exceeds 400%, the aperture ratio decreases, and the visible light transmittance becomes less than 60%. When the blistering ratio is within 400%, the visible light transmittance can be maintained at 60% or more. From the viewpoint of invisibility, the swelling ratio is more preferably within 200%. As a method of reducing the swelling ratio of a line, there are a method of thinning a line near an intersection of lines, a slit at an intersection of lines, and drawing a figure such as a circle at an intersection of lines. For example, as shown in FIG. 1 and FIG. 2, the line near the intersection of the line of the geometrical figure of the mask used in the chemical etching method is narrowed so that the intersection of the line of the geometrical figure drawn by the conductive metal. The line near the portion becomes substantially uniform, and the swelling ratio can be reduced. Further, as shown in FIG. 3, a figure can be formed at the intersection of the lines to increase the light transmittance. The figure is appropriately determined from electromagnetic wave shielding properties such as a circle, an ellipse, a square, a trapezoid, and a polygon and the light transmittance.

The following are representative examples of the adhesive used in the present invention. It is preferable that the adhesive layer has a function of flowing when heated or pressurized and has an adhesive function. In the electromagnetic wave shielding adhesive film of the present invention, as shown in FIG. 8, an adhesive layer is provided on a plastic film, and a geometric figure drawn with a conductive metal is formed thereon. The adhesive layer adheres a plastic film and a geometric figure drawn with a conductive metal, and when this is further adhered to an adherend, a display, a plastic plate, a plastic film, a glass plate, etc., the adhesive layer is formed. Flows through the space where the geometrical figure is not formed and adheres to the adherend. For this reason, it is preferable that the adhesive layer flows by heating or pressing. Also, when the bonding surface of the conductive metal is roughened to form a geometric figure and improve the adhesiveness, the roughened surface is transferred to the adhesive layer, and light is irregularly reflected on the roughened surface. However, when the adhesive layer flows, the transfer shape of the roughened surface is eliminated by the flow, and the light transmittance can be improved. For these reasons, the adhesive layer preferably flows by heating and pressurizing, and an adhesive composition such as a thermoplastic, thermosetting, or actinic ray-curable resin is preferable. As these adhesives, bisphenol A type epoxy resin and bisphenol F type epoxy resin,
Epoxy resins such as tetrahydroxyphenylmethane type epoxy resin, novolak type epoxy resin, resorcinol type epoxy resin, polyalcohol / polyglycol type epoxy resin, polyolefin type epoxy resin, alicyclic and halogenated bisphenol can be used. Other than epoxy resin, natural rubber, polyisoprene, poly-1,
2-butadiene, polyisobutene, polybutene, poly-
(Di) enes such as 2-heptyl-1,3-butadiene, poly-2-t-butyl-1,3-butadiene, poly-1,3-butadiene, polyoxyethylene, polyoxypropylene, polyvinyl ethyl ether And polyethers such as polyvinyl hexyl ether and polyvinyl butyl ether, polyesters such as polyvinyl acetate and polyvinyl propionate, polyurethane, ethyl cellulose, polyvinyl chloride, polyacrylonitrile, polymethacrylonitrile, polysulfone, polysulfide, and phenoxy resin. be able to. These exhibit a suitable visible light transmittance.

In addition to the above resins, polyethyl acrylate, polybutyl acrylate, poly-2-ethylhexyl acrylate, poly-t-butyl acrylate, poly-3-ethoxypropyl acrylate, polyoxycarbonyltetramethacrylate, polymethyl acrylate , Polyisopropyl acrylate, polydodecyl methacrylate, polytetradecyl methacrylate, poly-
n-propyl methacrylate, poly-3,3,5-trimethylcyclohexyl methacrylate, polyethyl methacrylate, poly-2-nitro-2-methylpropyl methacrylate, polytetracarbanyl methacrylate,
Poly (meth) acrylates such as poly-1,1-diethylpropyl methacrylate and polymethyl methacrylate 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.

Further, epoxy acrylate, urethane acrylate, polyether acrylate, polyester acrylate and the like can be used as the copolymer resin of acrylic resin and non-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.

Examples of the curing agent for the adhesive include amines such as triethylenetetramine, xylenediamine, and diaminodiphenylmethane; and acids such as phthalic anhydride, maleic anhydride, dodecylsuccinic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride. Anhydride, diaminodiphenyl sulfone, tris (dimethylaminomethyl) phenol, polyamide resin, dicyandiamide, ethylmethylimidazole, and the like can be used. These may be used alone or as a mixture of two or more. The amount of the crosslinking agent to be added is selected in the range of 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the polymer. If the 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 adhesion. The resin composition of the adhesive used in the present invention may optionally contain additives such as a diluent, a plasticizer, an antioxidant, a filler and a tackifier. The resin composition of the adhesive is applied to the surface of the plastic film to form a plastic film with a conductive metal to which a conductive metal is attached.

The plastic plate used in the present invention is a plate made of plastic, specifically, a polystyrene resin, an acrylic resin, a polymethyl methacrylate resin,
Polycarbonate resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene resin, polypropylene resin, polyamide resin, polyamideimide resin, polyetherimide resin, polyetherketone resin, polyarylate resin, polyacetal resin, polybutylene terephthalate resin, polyethylene terephthalate Thermoplastic polyester resin such as resin, cellulose acetate resin, fluororesin, polysulfone resin, polyethersulfone resin,
Thermoplastic resins and thermosetting resins such as polymethylpentene resin, polyurethane resin and diallyl phthalate resin are exemplified. Among these, a polystyrene resin, an acrylic resin, a polymethyl methacrylate resin, a polycarbonate resin, a polyvinyl chloride resin, a polyethylene terephthalate resin, and a polymethyl pentene resin having excellent transparency are preferably used. The thickness of the plastic plate used in the present invention is from 0.5 mm to 5 mm for protection and strength of the display.
It is preferable from the viewpoint of handling.

As the infrared absorber used in the present invention, metal oxides such as iron oxide, cerium oxide, tin oxide and antimony oxide, or indium-tin oxide (hereinafter referred to as IT)
O), tungsten hexachloride, tin chloride, cupric sulfide, chromium-cobalt complex, thiol-nickel complex or aminium compound, diimonium compound (trade name, manufactured by Nippon Kayaku Co., Ltd.) or anthraquinone (SIR-11)
4), metal complex systems (SIR-128, SIR-130,
SIR-132, SIR-159, SIR-152, S
IR-162), phthalocyanine (SIR-103)
(Made by Mitsui Toatsu Chemical Co., Ltd., trade names) and the like, and it is preferable to include these in the adhesive layer. In addition, the composition dispersed in the binder resin may be applied to the adhesive layer surface of the adhesive film or the back surface of the adhesive film, or may be directly applied to a plastic film to form an adhesive layer thereon. Further, a plastic film in which an infrared absorbing agent is previously contained in the plastic film can also be used. Among these infrared absorbing compounds, those having the effect of absorbing infrared rays most effectively are infrared absorbing agents such as cupric sulfide, ITO, aminium compounds, diimonium compounds and metal complexes. In the case of infrared absorbers other than organic infrared absorbers, what should be noted 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. The infrared-absorbing material is a binder resin, such as bisphenol A epoxy resin, bisphenol F epoxy resin, epoxy resin such as novolak epoxy resin, polyisoprene,
Diene resins such as poly-1,2-butadiene, polyisobutene and polybutene; polyacrylate copolymers composed of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, etc .; polyvinyl acetate; polyvinyl propionate Are dispersed uniformly in a binder resin such as a polyester resin such as polyester resin, polyethylene, polypropylene, polystyrene, and polyolefin resin such as EVA.
The optimum amount of the compound is 0.01 to 10 parts by weight of the infrared absorbing material with respect to 100 parts by weight of the binder resin, and more preferably 0.1 to 5 parts by weight. If it is less than 0.01 part by weight, the infrared ray shielding effect is small, and if it exceeds 10 parts by weight, transparency is impaired. The adhesive layer containing the infrared absorbing agent is preferably formed on one surface of a plastic film, and the surface of the adhesive layer is preferably coated with a conductive metal. Further, as described above, a composition containing an infrared absorber may be formed on the surface of a plastic film, and an adhesive layer (which may or may not contain the infrared absorber) may be formed thereon. Alternatively, an adhesive layer may be formed on the surface of a plastic film, and a composition containing an infrared absorbent may be formed thereon. Further, it may be formed on the surface of the electromagnetic wave shielding adhesive film opposite to the conductive metal. Further, it may be formed on any layer of the electromagnetic wave shielding structure composed of the electromagnetic wave shielding adhesive film and the plastic plate. For example, in the case of an electromagnetic shielding structure composed of one electromagnetic shielding adhesive film and one plastic plate, a surface A of the electromagnetic shielding adhesive film, a surface B between the electromagnetic shielding adhesive film and the plastic plate, a plastic It may be formed on any one of the surfaces C of the plate. In this case, the composition containing the infrared absorbing agent may be directly formed on at least one of the surfaces A, B, and C. At least one layer containing an infrared absorber is required, and the other layers may not contain an infrared absorber. It is preferable that the layer containing the infrared absorbing agent has adhesiveness, because workability and workability are easy. These compositions are applied in a thickness of 0.1 to 10 μm on the adhesive side or the back side 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 addition amount is optimally 0.01 to 5 parts by weight from the viewpoint of effect and transparency with respect to 100 parts by weight of the polymer which is a main component of the adhesive.

According to the present invention, the portion of the plastic film from which the conductive metal has been removed is intentionally provided with irregularities in order to improve the adhesion, or the transfer of the back shape of the conductive metal is performed. Although light is scattered on the surface and transparency is impaired, it is considered that when a resin having a refractive index close to that of the plastic film is present on the uneven surface, irregular reflection is suppressed to a minimum and transparency is exhibited. Further, a geometric figure formed of a conductive metal on a plastic film cannot be visually recognized by the naked eye because the line width is very small. In addition, the pitch is sufficiently large, and it is considered that apparent transparency is exhibited. Further, it is considered that the pitch of the geometrical figure is sufficiently smaller than the wavelength of the electromagnetic wave to be shielded, and excellent shielding properties are exhibited. In addition, the swelling of the intersection between the lines forming the geometrical figure due to the blistering at the intersection of the lines can be reduced by narrowing the line near the intersection of the lines, forming a slit, and adding a figure such as a circle to the intersection. By drawing, the blistering ratio can be suppressed to within 400% and the aperture ratio can be improved.

[0020]

EXAMPLES Next, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. Example 1 <Electromagnetic Wave Shielding Adhesive Film 1 and Electromagnetic Wave Shielding Construct 1> A 50 μm-thick polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., trade name A-4100, refractive index n = 1) as a plastic film .57
Using 5), the following adhesive layer 1 was applied to one surface thereof at room temperature using an applicator so as to have a predetermined dry coating thickness, and heated and dried at 90 ° C. for 20 minutes. The adhesive layer 1
Through an electrolytic copper foil having a thickness of 12 μm, which is a conductive metal,
180 ° C., with the roughened surface facing the adhesive layer
Heat lamination was performed under the conditions of 30 kgf / cm ² to obtain a PET film with a copper foil, which is a plastic film with a conductive metal. The obtained PET film with a copper foil was passed through a photolithography process using a chemical etching method (resist film sticking-exposure-development-chemical etching-resist film peeling). The mask used had a thin line near the intersection of the geometric figure lines (FIG. 1). In this step, the line width is 25 μm.
A copper lattice pattern having a length of 250 m and a line interval of 250 μm was formed on the PET film, and an electromagnetic wave shielding adhesive film 1 was obtained. The visible light transmittance of the adhesive film 1 was 20% or less. Then, the surface on which the adhesive layer is formed is brought into contact with a commercially available acrylic plate (como glass, manufactured by Kuraray Co., Ltd., trade name: 3 mm, n = 1.49) using a roll laminator. 110 ° C., 20 kgf / cm ² , 1
It was heated and pressed under the condition of 5 minutes to obtain an electromagnetic wave shielding component 1. Example 1 An electromagnetic wave shielding adhesive film 1 produced using the composition of the adhesive layer 1 such that the thickness of the adhesive layer 1 after drying was 20 μm and an electromagnetic wave shielding structure 1 obtained from a plastic plate were used in Example 1. And

<Composition of Adhesive Layer 1> In a 500 cm ³ three-necked flask, 200 cm ³ of toluene, 50 g of methyl methacrylate (MMA), and ethyl methacrylate (EMA) were used.
5 g, 2 g of acrylamide (AM) and 250 mg of AIBN were added, and the mixture was bubbled with nitrogen at 100 ° C. for 3 hours.
Stirring was performed at reflux. The polymer obtained by reprecipitation with methanol was filtered and dried under reduced pressure to synthesize a polyacrylate. The yield was 75% by weight. This was used as the main component of the adhesive layer 1. Polyacrylic acid ester (MMA / EMA / AM = 88/9/3, Mw = 700,000) 100 parts by weight SIR @ 159 (infrared absorbent: trade name, manufactured by Mitsui Toatsu Chemicals, Inc.) 0.5 part by weight Toluene 450 parts by weight Ethyl acetate 10 parts by weight The refractive index of the composition after solvent drying is 1.48 and the softening point is 1
05 ° C.

Example 2 <Electromagnetic Wave Shielding Adhesive Film 2 and Electromagnetic Wave Shielding Construct 2> The following adhesive layer 2 was applied to one surface of a PET film having a thickness of 25 μm at room temperature using an applicator.
C. and dried by heating for 20 minutes. An aluminum foil having a thickness of 25 μm was heated and laminated through the adhesive layer 2 in the same manner as in Example 1 to obtain a PET film with an aluminum foil. The PET film with the aluminum foil was subjected to the same photolithography process as in Example 1 to obtain a line width of 15 μm and a line interval of 12 μm.
An aluminum grid pattern of 5 μm was formed on a PET film to produce an electromagnetic wave shielding adhesive film 2. The visible light transmittance of this electromagnetic wave shielding adhesive film 2 is 20
% Or less. This electromagnetic wave shielding adhesive film 2
A hot press machine was used at 120 ° C., 30 Kgf / cm ² , and 30 minutes so that the surface on which the adhesive layer was formed was in contact with a commercially available acrylic plate (Komoray Co., Ltd., trade name: Como Glass, thickness 3 mm). This was used and heated and pressed to obtain an electromagnetic wave shielding component 2. Example 2 An electromagnetic wave shielding adhesive film 2 produced using the composition of the adhesive layer 2 and having a thickness of the adhesive layer 2 after drying of 40 μm and an electromagnetic wave shielding structure 2 obtained from a plastic plate were used in Example 2. And

<Composition of Adhesive Layer 2> TBA-HME (manufactured by Hitachi Chemical Co., Ltd., high molecular weight epoxy resin, Mw = 300,000) 100 parts by weight UFP @ HX (infrared absorbent: manufactured by Sumitomo Metal Mining Co., Ltd.) 0.4 parts by weight MEK 330 parts by weight Cyclohexanone 15 parts by weight The refractive index of the composition after drying in a solvent is 1.57, and the softening point is 7.
9 ° C.

Example 3 <Electromagnetic Wave Shielding Adhesive Film 3 and Electromagnetic Wave Shielding Construct 3> The following adhesive layer 3 was applied on one side of a 50 μm-thick PET film at room temperature using an applicator.
C. and dried by heating for 20 minutes. An electromagnetic shielding adhesive film in which a nickel grid pattern having a line width of 10 μm, a line interval of 100 μm, and a thickness of 1 μm is formed on a PET film by forming electroless nickel plating in a grid on the adhesive layer using a mask layer. 3 was produced.
The mask layer used had a thin line near the intersection of the lines of the grid pattern (FIG. 1).
The visible light transmittance of the adhesive film 3 was 20% or less. Using a roll laminator, the electromagnetic wave shielding adhesive film 3 was placed at 110 ° C. at a temperature of 110 ° C. so that the surface coated with the adhesive was in contact with a commercially available acrylic plate (commercial glass, manufactured by Kuraray Co., Ltd., 3 mm in thickness).
It was heated and pressed under the condition of 20 kgf / cm ² to obtain an electromagnetic wave shielding component 3. Example 3 An electromagnetic wave shielding adhesive film 3 produced using the composition of the adhesive layer 3 and having a thickness of the adhesive layer 3 after drying of 5 μm and an electromagnetic wave shielding structure 3 obtained from a plastic plate were used in Example 3. And

<Composition of Adhesive Layer 3> Byron UR-1400 (trade name, manufactured by Toyobo Co., Ltd., saturated polyester resin, Mn = 40,000) 100 parts by weight IRG # 002 (infrared absorbent: Nippon Kayaku Co., Ltd.) 1.2 parts by weight MEK 285 parts by weight Cyclohexanone 5 parts by weight The refractive index of the composition after drying in a solvent is 1.55, and the softening point is 8
3 ° C.

Example 4 The composition of the polyacrylate, which is the main component of the composition of the adhesive layer 1, was changed to MMA (methyl methacrylate) / BA (butyl acrylate) / AA
(Acrylic acid) = 85/10/5, molecular weight Mw = 550,000, and the other composition of the adhesive layer 1 was the same as the composition of the adhesive layer 4, and the electromagnetic wave shield of Example 1 was used. Example 4 was an electromagnetic wave shielding structure 4 produced in the same manner as the conductive adhesive film 1 and the electromagnetic wave shielding structure 1. The solvent of the composition of the adhesive layer 4 after drying the solvent had a refractive index of 1.47 and a softening point of 99 ° C.

Example 5 A polyacrylate ester as a main component of the composition of the adhesive layer 1 was converted to a polybutadiene elastomer (Poly bd R-made by Idemitsu Petrochemical Co., Ltd.).
45HT) was used as the composition of the adhesive layer 5, and the other conditions were the same as those in Example 1 to obtain an electromagnetic wave shielding component 5 as Example 5. The solvent of the composition of the adhesive layer 5 after drying the solvent had a refractive index of 1.50 and a softening point of 61 ° C.

Example 6 An adhesive layer was prepared by changing the polyacrylic acid ester, which is the main component of the composition of the adhesive layer 1, to Byron-200 (trade name, manufactured by Toyobo Co., Ltd., Mn = 15,000). The composition of Example 6 was used, and the other conditions were the same as those of Example 1 to obtain an electromagnetic wave shielding component of Example 6. The solvent of the composition of the adhesive layer 6 after drying was 1.55 in refractive index and 163 ° C. in softening point.

Example 7 A plastic film was made of PE
From T (25 μm) to polycarbonate (50 μm)
An electromagnetic wave shielding member 7 was obtained in the same manner as in Example 2 except that the thickness of the adhesive was changed from 40 μm to 30 μm.

(Embodiment 8) The line width is changed from 10 μm to 30
Example 8 was repeated except that the line spacing was changed from 100 μm to 500 μm, and the thickness of the adhesive layer was changed from 5 μm to 10 μm.
And

(Embodiment 9) PET through a photolithography process
An electromagnetic wave shielding structure 9 obtained in the same manner as in Example 1 except that the copper lattice pattern formed on the film was subjected to a blackening treatment was used as Example 9.

COMPARATIVE EXAMPLE 1 In the photolithography step, an electromagnetic wave shielding structure obtained in the same manner as in Example 1 except that a mask having a uniform geometric pattern line width (FIG. 7) was used. 10 was designated as Comparative Example 1.

Comparative Example 2 An electromagnetic wave shielding structure obtained in the same manner as in Example 2 except that in the photolithography process, a mask having a uniform geometric pattern line width (FIG. 7) was used. 11 was set as Comparative Example 2.

Comparative Example 3 In forming the electroless nickel plating, the same procedure as in Example 3 was carried out except that a mask layer having a uniform grid pattern line width (FIG. 7) was used. The obtained electromagnetic wave shielding structure 12 was used as Comparative Example 3.

The opening ratio of the mesh, the blistering ratio of the lines, the electromagnetic wave shielding property, the visible light transmittance, the invisibility, and the adhesive characteristics before and after the heat treatment of the electromagnetic wave shielding structure obtained as described above were measured. The results are shown in Table 1.

The refractive index of the composition of the adhesive layer was measured with a refractometer (Abago Refractometer, manufactured by Atago Optical Machine Works). The softening point was measured with a scanning differential calorimeter (910-DSC, manufactured by DuPont). The aperture ratio and the blistering ratio of a geometric figure drawn with a conductive metal were measured based on a micrograph. The electromagnetic wave shielding property is measured by inserting a sample between flanges of a coaxial waveguide converter (manufactured by Japan High Frequency Corporation, TWC-S-024), and using a spectrum analyzer (Y
HP 8510B vector network analyzer) at a frequency of 300 MHz. The measurement of the visible light transmittance was performed using a double beam spectrophotometer (manufactured by Hitachi, Ltd., Model 200-10), 400 to 700.
The average value of the transmittance in nm was used. The average value of the infrared absorptivity in the region of 900 to 1,100 nm was used for the infrared shielding factor using a spectrophotometer (U-3410, manufactured by Hitachi, Ltd.). The non-visibility is evaluated by seeing or not recognizing the geometrical figure formed of the conductive metal by visually observing the adhesive film attached to the glass plate from a place 0.4 m away, and making the unrecognizable one good. N which can be recognized
G. The adhesive force was measured using a tensile tester (Tensilon UTM-4-100 manufactured by Toyo Baldwin Co., Ltd.) at a width of 10 mm, a direction of 90 °, and a peeling speed of 50 mm / min.

[0037]

[Table 1]

The visible light transmittance of Comparative Examples 1 to 3 in which the swelling ratio exceeds 400% is compared with the corresponding visible light transmittance of Examples 1 to 3 in which the swelling ratio of the present invention is 400% or less. Significantly inferior. On the other hand, electromagnetic wave shielding properties and infrared ray shielding properties showed equivalent values.

[0039]

As is clear from the examples, the electromagnetic wave shielding adhesive film obtained by the present invention has a blistering ratio at a line intersection of a geometrical figure drawn with a conductive metal.
By setting it within 400%, the visible light transmittance can be maintained at 60% or more. Further, it is possible to provide an adhesive film having good electromagnetic wave shielding properties. Then, by drawing a geometric figure on the conductive metal by the chemical etching method, it is possible to provide an electromagnetic wave shielding adhesive film having electromagnetic shielding properties, workability, mass productivity, and low cost.
And, an electromagnetic wave shielding adhesive film is bonded to at least one surface of the plastic plate, and further, by forming an electromagnetic wave shielding structure in which an adhesive or an adhesive film having infrared light shielding characteristics is bonded to the other surface, An electromagnetic wave shielding substrate having transparency can be provided. By using an electromagnetic wave shielding adhesive film having an electromagnetic wave shielding property and transparency for a display, it is possible to provide a display that is lightweight, compact, has excellent transparency, and has little electromagnetic wave leakage. Further, by using an electromagnetic wave shielding component having electromagnetic wave shielding properties and transparency for a display, a display that is lightweight, compact, has low electromagnetic wave leakage, and also serves as a display protection plate can be provided. When used for a display, it has a large visible light transmittance and good invisibility, so that a clear image can be comfortably viewed under almost the same conditions as in a normal state without increasing the luminance of the display. Since the electromagnetic wave shielding adhesive film and the electromagnetic wave shielding structure of the present invention are excellent in electromagnetic wave shielding properties and transparency, in addition to a display, a measuring device, a measuring device, and a manufacturing device for generating or protecting from electromagnetic waves It can be used by providing it in windows and housings, especially windows such as windows where transparency is required.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view showing a geometric figure of a mask used in an embodiment of the present invention.

FIG. 2 is a partially enlarged view showing a geometrical figure of a mask used in another embodiment of the present invention.

FIG. 3 is a partially enlarged view showing a geometrical figure of a mask used in still another embodiment of the present invention.

FIG. 4 is a diagram illustrating a blister rate of a line.

FIG. 5 is a diagram illustrating a blister rate of a line.

FIG. 6 is a diagram illustrating a blister rate of a line.

FIG. 7 is a partially enlarged view showing a geometrical figure of a mask used in a conventional example.

FIG. 8 is a perspective view of (a) an electromagnetic wave shielding adhesive film of the present invention, (b) a partially enlarged perspective view, (c) a cross-sectional view thereof, and (d) a display of the electromagnetic wave shielding adhesive film of the present invention. FIG.

[Explanation of symbols]

 1. 1. Adhesive layer 2. Geometric figures drawn with conductive metal Plastic film4. 4. Electromagnetic wave shielding adhesive film Display screen

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Minoru Tosaka 1500 Oji Ogawa, Shimodate City, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd. Within Shimodate Research Laboratory (72) Inventor Nobuyoshi Muto 1500 Shimodate Ogawa, Shimodate City, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd.

Claims (13)

[Claims] 1. A plastic film with a conductive metal having an adhesive layer, comprising a geometric figure drawn by a conductive metal, wherein a line width of the geometric figure is 40 μm or less, a line interval is 100 μm or more, and a line thickness. Is 40 μm or less, and the blistering ratio at the line intersection is within 400%. 2. The electromagnetic wave shielding adhesive film according to claim 1, wherein the geometrical figure drawn by the conductive metal is formed by a chemical etching method. 3. A geometrical figure drawn by a conductive metal by a chemical etching method by narrowing a line width at a line intersection portion in a line width forming the geometrical figure. The adhesive film according to claim 2. 4. The electromagnetic wave shielding adhesive film according to claim 1, wherein a figure is formed at a line intersection of the conductive metal at a line width for forming a geometric figure. 5. The electromagnetic wave shielding adhesive film according to claim 1, wherein the plastic film is a polyethylene terephthalate film or a polycarbonate film. 6. The method according to claim 1, wherein the conductive metal is a paramagnetic metal.
6. The electromagnetic wave shielding adhesive film according to claim 1. 7. The conductive metal is copper having a thickness of 1 to 40 μm,
The electromagnetic wave shielding adhesive film according to any one of claims 1 to 5, wherein the adhesive film is aluminum or nickel. 8. The electromagnetic wave shielding adhesive film according to claim 7, wherein the conductive metal is copper, and at least the surface thereof is blackened. 9. The electromagnetic wave shielding adhesive film according to claim 1, wherein the adhesive layer contains an infrared absorbing agent. 10. An electromagnetic wave shielding structure comprising the electromagnetic wave shielding adhesive film according to any one of claims 1 to 9 bonded to at least one surface of a plastic plate. 11. The electromagnetic wave shielding adhesive film according to claim 1 is bonded to at least one surface of a plastic plate, and the other surface is bonded to an infrared shielding adhesive or an adhesive film. Electromagnetic wave shielding structure. 12. A display using the electromagnetic wave shielding adhesive film according to any one of claims 1 to 9. 13. A display using the electromagnetic wave shielding structure according to claim 10.