JP3076473B2 - Laminated type anti-reflection body and anti-reflection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated type anti-reflective body and a method of preventing radio wave reflection, which can prevent an obstacle due to radio waves and can be made thinner and lighter.

[0002]

2. Description of the Related Art Conventionally, a method of applying a conductive paint to a housing of an electronic device or a method of applying zinc, aluminum, iron, copper on a plastic substrate in order to avoid malfunction due to radio waves in an electronic device or the like. There is known a method of forming a metal thin film such as by plating, bonding, vapor deposition, and the like. However, the method of applying the conductive paint to the housing has a small radio wave shielding effect,
In addition, there is a disadvantage that the effect tends to decrease over time. Further, in the method of forming a metal thin film on a plastic base material, the amount of reflected radio waves is large, and there is a problem of obstacles due to secondary radio waves. Further, Japanese Patent Application Laid-Open No. 2-241098 describes an electromagnetic wave shielding film in which a geometric pattern is drawn on the surface of a film using a conductive metal, and this film has excellent electromagnetic wave shielding properties. However, any of these materials can effectively function as a shielding material for preventing leakage of electromagnetic waves generated from electronic devices or the like or preventing malfunction of electronic devices due to external electromagnetic waves. However, it does not work effectively to prevent radio interference such as a false image of a radar caused by reflection of a radio wave from a bridge, a building or the like.

As a means for preventing such obstacles due to the reflection of radio waves, a radio wave absorption material in which ferrite or a mixture of ferrite and metal powder or carbon powder is dispersed in an organic polymer is known. However, in order to obtain practical absorption characteristics with the above materials, even in the case of radio waves having a narrow band frequency (effective band width of about 0.5 to less than 1 GHz), the weight is at least 4 kg / m ² and the film thickness is 1 mm or more. In the case of a radio wave having an effective bandwidth of about 1 to 5 GHz, a film thickness of at least about 12 kg / m ² or more and 4.5 mm or more is required. Therefore, there are drawbacks in that the thickness and weight are large when used, and the workability is poor, and when the work is performed on a building or the like, consideration must be given to the strength and balance of the whole building. Therefore, there has been a demand for the development of a radio wave antireflection body having a thin film, light weight, good workability, and excellent radio wave shielding ability and radio wave reflection preventing ability.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on an anti-reflection member and an anti-reflection method to solve the above-mentioned problems. As a result, a pattern made of a specific material formed in a geometric pattern is obtained. Have been found to be capable of shielding radio waves and exhibiting excellent radio wave reflection preventing ability by laminating a structure formed by laminating a plurality of layers on a radio wave reflector via a resin layer, and completed the present invention.

The above effects of the present invention are quite difficult to predict from the prior art. That is, the feature of the present invention is that, by forming a layer made of a specific material in a pattern shape and mounting a plurality of laminated layers via a resin layer on a radio wave reflector, surprisingly, It has been found that it is possible to effectively prevent the reflection of radio waves even in a thin and thin film. That is, when the pattern layer is not provided, a heavy ferrite film layer having a large weight is required as in the conventional case. These problems have been solved by the present invention having the above-described effects.

That is, the present invention provides: A pattern layer (A) formed in a geometric pattern, a support layer (B) which may be interposed if necessary, a resin layer (C), and a support layer (D) which may be interposed if necessary Are laminated as one unit, and the laminate unit is the layer (C) on the layer (A) side.
Alternatively, a plurality of unit laminates formed by laminating a plurality of units so as to face the layer (D) side are provided on the radio wave reflector layer (E) with the layer (C) or layer (D) side of the plurality of unit laminates being a layer (E) A radio wave anti-reflection body having a structure laminated so as to face (E), wherein all or at least one layer of the pattern layer (A) has a volume resistivity of 10 ⁻³ to 10 ³ Ω · cm. And a layer (A) other than the pattern layer of the coating film is a metal pattern layer.

Further, the present invention provides: Item 4. The radio wave antireflective member according to Item 1, wherein the pattern layer of the coating film is formed by applying a coating material containing a film-forming resin and a conductive powder.

The present invention also provides: The above item 1 or 2, wherein the resin layer (C) contains at least one kind of powder selected from ferrite, carbon, metal powder and conductive metal oxide, and if necessary, a high dielectric material. 2. An anti-reflection member according to item 2.

Further, the present invention relates to 4. The resin layer (C) is paper,
After applying a paint obtained by dispersing at least one kind of powder selected from ferrite, carbon, metal powder and conductive metal oxide and, if necessary, a high dielectric material to a binder, on a cloth, a nonwoven fabric or a porous sheet. 3. An anti-reflective member for radio waves according to item 3, characterized by being molded under pressure.

[0010] The present invention also provides: Item 5. The radio wave antireflective body according to any one of Items 1 to 4, further comprising a clear or colored coating layer provided on the uppermost pattern layer (A) of the radio wave antireflective body. Things.

[0011] The present invention further provides a method of the present invention. An object of the present invention is to provide a radio wave anti-reflection method comprising forming the radio wave anti-reflection body according to any one of the above items 1 to 5 on a structure.

[0012] The present invention also provides a method according to the seventh aspect. A radio wave characterized by forming a plurality of unit structures on the radio wave reflection structure having a metal surface, wherein the radio wave reflection layer (E) is removed from the radio wave antireflection body according to any one of Items 1 to 5 above. An anti-reflection method is provided.

In the anti-reflective member of the present invention, the pattern layer (A) is laminated on the resin layer (C) with or without the support layer (B). The pattern layer (A) may be formed directly on the resin layer (C), or after being formed on the support layer (B), the layer (B) side may be bonded to the resin layer (C). A support layer (D) may be laminated on the surface of the resin layer (C) opposite to the layer (A) or the layer (B). In the radio wave reflector of the present invention, the layer (A), the layer (B) which may be interposed if necessary, the layer (C) and the layer (D) which may be interposed if necessary are sequentially laminated. A plurality of the laminates are laminated as one unit to form a multi-unit laminate.

In the above multi-unit laminate, all or at least one layer of the pattern layer (A) has a volume resistivity value of 10
^-3 it is a patterned layer of coating having a ~10 ³ Ω · cm. The pattern layer of the coating film is formed by, for example, at least one kind of conductive powder such as a metal powder, a conductive carbon powder, and a conductive metal oxide powder in a resin, and, if necessary, a solvent, a sagging agent, and a defoaming agent. , Containing a pigment dispersant, other paint additives, etc., kneading, and applying a paint (including ink-like ones) dispersed in a known manner such as stirring and the like in a pattern,
It is obtained by forming a coating film. The powder blended in the resin may have any shape such as a sphere, a plate, a square, and a whisker.

Examples of the metal powder to be incorporated in the paint for forming the pattern layer of the coating film include metal powders such as nickel, aluminum, copper, iron, cobalt, zinc, and tungsten. The size and content of the metal powder are not particularly limited, but the particle size is generally preferably 100 μm or less from the viewpoint of dispersibility.
Usually, the content is preferably 50 to 500 parts by weight based on 100 parts by weight of the resin solid content.

The resin to be incorporated in the paint for forming the pattern layer of the coating film may be a film-forming resin, and may be a film-forming resin used in the field of paint or ink. Acryl resin, polyester resin, epoxy resin, polyurethane resin, polyamide resin, polyimide resin, polyvinyl chloride resin, butadiene-styrene rubber, nitrile rubber, natural rubber, and the like. When these resins are used, a curing agent such as aminoplast or polyisocyanate, which can react with these resins and crosslink, may be added.

The paint for forming the pattern layer of the coating film is applied on the resin layer (C) or the support layer (B) by a method such as a pattern printing method such as screen printing, a masking method, and a spray method using a pattern. To form a pattern layer of a coating film. The thickness of the pattern layer of this coating film is usually 1
The range of 0 to 500 μm is preferred.

In the multi-unit laminate, the remaining pattern layer (A) other than the pattern layer of the coating film is a metal pattern layer. When all of the pattern layers (A) are pattern layers of the coating film, there is no metal pattern layer. Platinum, as the type of metal forming the metal pattern layer,
Gold, silver, nickel, chromium, aluminum, copper, zinc,
Tungsten and iron are exemplified. The thickness of the metal of this metal pattern layer is 0.5 to 50 in terms of strength, weight, and the like.
The range of μm is preferred. It is preferable from the viewpoint of radio wave absorption efficiency that the laminate unit having the metal pattern layer is empirically arranged on the inner layer side of the multiple unit laminate and is not disposed as an externally facing surface layer. As a method of forming the metal pattern layer, a conventionally known method such as an etching method of etching a metal foil or sheet to form a pattern, a pattern plating method, and a transfer method can be used.

Regardless of whether a coating layer or a metallic pattern layer (A) is formed on the support layer (B), the support layer (B) is adhered to the resin layer (C) with an adhesive or the like. Then, the pattern layer (A) may be formed thereon, or after forming the pattern layer (A) on the support layer (B) alone,
The support layer (B) having the obtained pattern layer (A) may be stuck on the resin layer (C).

The shape of the pattern layer (A) may be a geometric pattern formed of a plate-like or cord-like metal, for example, a plate-like metal such as a circle, a square, a polygon, a ring, and an irregular shape. Even if a plurality is arranged in a geometric pattern such as a checkerboard pattern, a lattice shape, a stripe shape, a polka dot shape, and the like as a graphic unit, the following figures 1 to 11 which are formed of a cord-like metal.
Patterns having a multilayer structure as shown in FIG.
The spiral pattern as shown in FIG.
Even in the unit, as shown in FIG. 12 and FIG.
They may be arranged in a checkerboard pattern, lattice pattern, stripe pattern, polka dot pattern, or the like. The patterns may be mixed in a plane.

In the pattern of the pattern layer (A), the area ratio of the pattern void portion / coating film or metal pattern portion is 0.1%.
It is preferably from 10 to 10, more preferably from 0.2 to 5. Also, the size of the figure unit in the pattern is preferably 30 mm or less in length, diagonal, and diameter on one side in the case of a plate, and the longest diameter and longest side in the case of a lace-like multilayer structure or spiral shape. For example, it is preferable that the longest linear distance between any two points on a pattern in a figure unit is 300 mm or less.

In the present invention, the support layer (B) is a layer which may be interposed between the pattern layer (A) and the resin layer (C) if necessary. The support layer (B) is used as needed as a support when forming the pattern layer (A) or the resin layer (C), for example. The support layer (B) is not particularly limited, but generally includes a plastic sheet having a thickness of about 10 to 500 μm. The plastic sheet includes a plastic film. Although there is no particular limitation on the type of plastic sheet, polyamide,
Polyester such as polyimide, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polyurethane, hypalon rubber, chloride rubber, chloroprene rubber,
Epoxy resins, acrylic resins, phenol resins and the like can be mentioned. The plastic sheet includes a fiber-reinforced plastic sheet.

In the present invention, the support layer (D) is a layer which may be interposed if necessary on the side opposite to the pattern layer (A) side of the resin layer (C). It is used as needed as a support when the resin layer (C) is formed by coating. As the support layer (D), those usable as the support layer (B) can be similarly used.

In the present invention, as the resin layer (C), for example, polyimide, polyphenylene sulfide, rosin, shellac, ester rubber, hypalone (chlorosulfonated polyethylene) rubber, chloride rubber, chloroprene rubber, polyolefin resin, hydrocarbon resin, chloride resin Sheets of resin such as vinylidene resin, polyamide resin, polyetherketone resin, vinyl chloride resin, polyester resin, alkyd resin, phenolic resin, epoxy resin, acrylic resin, polyurethane resin, silicone resin, cellulose resin, and vinyl acetate resin No. Resin layer (C)
Further, in the above resin or resin solution, ferrite,
By forming at least one kind of powder selected from carbon, metal powder and conductive metal oxide and a dispersion obtained by dispersing a high dielectric material as necessary, into a sheet, or by forming the support layer (B) or the support layer (B). It can also be obtained by coating and drying on the layer (D), or by applying the above-mentioned dispersion (paint) to paper, cloth, non-woven fabric, porous sheet or the like and press-molding. The thickness of the resin layer (C) is not particularly limited, but is usually about 50 μm to
3 mm, preferably in the range of 100 μm to 2 mm.

As the ferrite that can be dispersed in the resin or the resin solution, ferrite conventionally used in radio wave absorbers can be used. Representative examples include hematite (Fe ₂ O ₃ ) and magnetite (Fe ₃ O ₃ ). ₄ ), an iron oxide containing a dissimilar metal element generally represented by a composition of MO.Fe ₂ O ₃ (M is Mn, Co, Ni, Cu, Zn,
Ba, Mg, etc.). The particle size of the ferrite is not particularly limited, but is generally 100 μm.
The following is desirable from the viewpoint of dispersibility and the like.

The carbon that can be dispersed in the resin or the resin solution is preferably carbon having conductivity, and examples thereof include so-called conductive carbon and carbon fiber. Although the particle size of carbon is not particularly limited, it is generally preferable that the particle size or the fiber diameter be 100 μm or less from the viewpoint of dispersibility and the like.

Examples of the metal powder that can be dispersed in the resin or the resin solution include metal powders of gold, platinum, silver, copper, nickel, aluminum, iron, and the like. Examples include tin oxide and indium oxide. These may be particulate or fibrous, or may be formed in a thin film by vapor deposition or the like on a particulate or fibrous polymer powder or inorganic powder. The particle size of the metal powder and the conductive metal oxide or the diameter of the fiber is not particularly limited, but it is generally preferable that the particle size or the diameter of the fiber be 100 μm or less from the viewpoint of dispersibility and the like.

The high dielectric material that can be optionally contained in the above resin or resin solution includes particles of barium titanate, strontium titanate, zirconium titanate, potassium titanate and the like, and titanium such as whisker. Acid compounds, silicon carbide, silicon nitride, and the like can be given. These high dielectric materials may be in the form of particles or fibers, and the particle size or fiber diameter is not particularly limited.
It is preferably at most 00 μm from the viewpoint of dispersibility and the like.

In the resin or the resin solution, at least one powder of the above ferrite, carbon, metal powder and conductive metal oxide is used alone or in combination.
If necessary, a high dielectric material can be added to these powders to mix, knead or disperse them. Binder 10
The blending amount of the powder with respect to 0 parts by weight is preferably within the following range. -In the case of ferrite alone, 100 to 400 parts by weight-In the case of one of carbon, metal powder and conductive metal oxide alone or in combination of two or more thereof, 3 to 2
0 parts by weight-When ferrite / (at least one of carbon, metal powder, and conductive metal oxide) is used in combination, the total amount is 3 to 400 parts by weight, and (carbon, metal powder, conductive metal oxide)
Is less than 20 parts by weight, and when ferrite / high dielectric material is used in combination, 100 to 4 in total
00 parts by weight, and the content of the high dielectric material is preferably
Less than 50% by weight of the total amount of these powders, (at least one of carbon, metal powder and conductive metal oxide) / 3 to 200 in total when used in combination with a high dielectric material
Parts by weight, and the total amount of (carbon, metal powder, conductive metal oxide) is less than 20 parts by weight; ferrite / (at least one of carbon, metal powder, conductive metal oxide) / high In the case of using a dielectric material together, the total amount is 3 to 400 parts by weight, the total amount of (carbon, metal powder, conductive metal oxide) is less than 20 parts by weight, and the content of the high dielectric material is preferably the total of the powders. 50% by weight of the amount
Less than.

In dispersing the powder in the resin or the resin solution, the resin powder and the powder can be dispersed by kneading under heating, and if necessary, a solvent for dissolving or dispersing the resin may be added. , Kneading, stirring, or the like, and dispersing the above powder by a known method. Further, a hardener such as aminoplast or polyisocyanate may be blended in these dispersions.

The paper, cloth, non-woven fabric or porous sheet used for obtaining the resin layer (C) by applying the above-mentioned dispersion and applying pressure to form a resin layer (C) has voids, and a coating and molding step. Is not particularly limited as long as the above-mentioned dispersion is impregnated, but those having a porosity of about 20 to 95% are preferred. Representative examples are cellulose-based paper; synthetic fibers such as nylon, polyester, acrylic, and polyimide; carbon fibers; ceramic fibers such as whisker titanate and silicone carbide; and fibers such as natural fibers such as cotton, hemp, and wool. Cloths and nonwoven fabrics; porous sintered sheets of ceramics obtained by sintering a mixture of an organic polymer and ceramics; porous sheets such as foamed plastic sheets; The thickness of the material to be coated such as paper, cloth, non-woven fabric or porous sheet is not particularly limited, but usually a thickness of about 50 μm to about 3 mm is used.

In the above-mentioned application and pressure molding, the dispersion is applied to the material to be coated, and if necessary, the solvent is removed by heating or the like, and then molding is performed under pressure to form the resin layer (C). can get. During this molding, heating can be performed if necessary. The coating material is impregnated with the coating material by this molding. When the binder of the coating material is thermosetting, it is preferable to perform heating and pressure molding in a so-called B stage.

The pressure conditions at the time of molding differ depending on the kind of the binder used and the properties of the material to be coated.
The range is 0 kg / cm ² . The heating conditions for heating as necessary during molding are usually in the range of room temperature to 250 ° C. The pressure treatment time is usually about 1 minute to 120 minutes. The impregnation ratio of the paint occupied by the paint solid content in the material to be coated is preferably 20 to 95% by volume with respect to the material to be coated including the voids. The amount of the paint applied to the material to be coated is such that the thickness of the resin layer (C) is usually about 50 μm to 3 mm, preferably 10 μm to 3 mm.
It is preferable to apply the coating so as to be in a range of 0 μm to 2 mm.

Although the function and effect of the resin layer (C) are not clear, the path length of the radio wave entering the inside from the coating of the pattern layer (A) or the void portion without metal is changed, and the inner layer (A) is changed. Alternatively, it is considered that the phase of the radio wave which is reflected by the layer (E) and exits from the coating of the pattern layer or the void portion having no metal to the outside is changed, whereby the coating or metal of the pattern layer (A) is changed. It is considered that the energy of the radio wave is lost by the interference between the reflected radio wave and the radio wave whose phase has been changed. At this time, if the resin layer (C) contains ferrite, carbon, metal powder, and conductive oxide, the change in path length becomes larger as compared with the case where these are not contained, and the absorption band of radio waves becomes wider. Tend. It is considered that the blending of the high dielectric material has a secondary effect on these effects. However, the inclusion of these powders increases the weight, and the use of these powders should be appropriately selected according to the intended use of the radio wave antireflection body.

In the radio wave antireflection body of the present invention, the pattern layer (A), the support layer (B) which may be interposed if necessary, the resin layer (C) and the support layer (D) which may be interposed if necessary ) Are sequentially laminated to form a laminate,
These layers may be bonded by an adhesive or the like. In the radio wave antireflection body of the present invention, a multi-unit structure is formed by laminating a plurality of the laminate units so that the layer (A) side faces the layer (C) or the layer (D) side, with the laminate as one unit. The body is laminated on the radio wave reflector layer (E) such that the layer (C) or layer (D) side of the structure faces the layer (E).

The number of layers of the laminate unit forming the plural unit structure is not particularly limited.
7, preferably 2 to 4. Even if the number of layers is 7 or more, the radio wave reflection preventing effect is not much improved, and it is disadvantageous in terms of weight and thickness, and has many man-hours for processing, which is economically disadvantageous. The pattern type and arrangement of the pattern layer (A) in each laminate unit may be the same or different in each unit, and the resin layer (C) may be the same or different in each unit. The support layer (B) or (D) may or may not be present in each unit, and may be the same or different. By laminating a plurality of laminate units, the frequency band in which the reflection of radio waves can be effectively prevented can be widened.

The above-mentioned radio wave reflector layer (E) makes the incoming radio wave 100% or almost 100% (about 99% or more).
Any metal layer that can reflect light may be used, and a metal sheet is generally used. The metal sheet also includes a metal foil. Examples of the type of the metal sheet include metal sheets such as tin, brass, copper, iron, nickel, stainless steel, and aluminum. The thickness of the metal sheet is not particularly limited, but is preferably about 5 to 500 μm from the viewpoint of strength and weight reduction.

[0038] In the radio wave antireflection body of the present invention, an adhesive may be adhered between the laminate units forming the plural unit laminate and between the plural unit laminate and the radio wave antireflection body. Further, the radio wave antireflective body of the present invention is provided on the uppermost pattern layer (A) in order to improve the anticorrosion properties, weather resistance, cosmetic properties, and retention of material properties of the radio wave antireflective body.
The clear or colored coating layer may be provided by painting or the like. Examples of the resin species forming the coating layer include an epoxy resin, a urethane resin, an acrylic resin, and a polyester resin.

In the radio wave reflection preventing method of the present invention, the radio wave anti-reflection body of the present invention is adhered to a structure to be shielded and prevented from radio wave reflection by using an adhesive or the like to thereby prevent the radio wave from being reflected and prevented. Can be effectively prevented from being reflected. Further, in the radio wave reflection prevention method of the present invention, when the structure to prevent the reflection of radio waves is a radio wave reflection structure having a metal surface, this radio wave reflection structure is the radio wave reflection prevention body of the present invention. Since a function of shielding radio waves and the like can be performed similarly to the radio wave reflector layer (E), a plurality of units obtained by removing the radio wave reflector layer (E) from the radio wave antireflective body are provided on the radio wave reflection structure. By forming a laminate, it is also possible to effectively prevent radio wave reflection.

Further, an adhesive is applied to the surface of the radio wave reflector layer (E) of the radio wave anti-reflection body of the present invention in advance, and release paper is laminated thereon, thereby peeling off the release paper at the construction site. A radio wave antireflection body can be formed on the structure simply by sticking.

[0041]

The present invention will be described more specifically with reference to the following examples. Hereinafter, “parts” are based on weight.

Production Example 1 On a polyimide film [(D) layer: film thickness 25 μm]
Barium ferrite 2 for 100 parts of acrylic resin
A coating containing 00 parts was applied so that the dry film thickness became 100 μm to form a resin layer (C). In addition, a conductive ink (volume resistivity of 3.1 × 10 ⁻³ Ω · cm of the obtained film) containing 100 parts of acrylic resin and 200 parts of nickel powder on a polyimide film [(B) layer: film thickness 25 μm].
The figure unit (the outermost side length is about 20 mm, the line width of the strap is about 250 μm, and the line interval (space) between the straps is about 250 μm) shown in FIG. Printing was performed so as to be arranged at intervals to form a pattern coating layer (A) having a film thickness of about 35 μm. Next, the obtained (D) layer having the (C) layer and the (B) layer having the (A) layer are combined with the (C) layer.
The layer and the layer (B) were adhered with an adhesive so as to face each other to obtain a laminate-1.

Production Example 2 On a release paper, 150 parts of nickel-based ferrite were added to 105 parts of a mixture of 100 parts of Epicoat 828 (a bisphenol A epoxy resin manufactured by Shell Chemical Co., Ltd.) and 5 parts of diethylenetetramine as a curing agent. An indium-tin oxide film is formed on a barium sulfate powder by a sputtering method so as to have a film thickness of about 10 nm, and a paint containing 50 parts of barium titanate and 10 parts of powder is dried to a film thickness of about 75%.
The resin layer (C) was formed on a release paper by coating and drying to a thickness of μm. On this resin layer (C), a conductive ink containing acrylic resin (100 parts) and nickel powder (150 parts) (volume resistivity of 2.3 × 10 ⁻¹ Ω ·
cm) and a figure unit like the figure unit shown in FIG. 15 (the shape of the cord band is a triangular spiral, and the length of the longest side of the outermost circumference is about 1).
2mm, line width 100μm, line spacing (space) 100μm
), The distance between vertices between each figure unit is 0.5 mm
After forming a pattern coating layer (A) having a thickness of about 50 μm by printing so as to form a pattern arranged as shown in FIG. 12, the release paper was peeled off to obtain a laminate-2.

Production Example 3 A paint containing 100 parts of barium-based ferrite and 10 parts of conductive carbon with respect to 100 parts of an acrylic resin was coated on a polyester film [(D) layer: film thickness 25 μm] to a dry film thickness of 200 μm. To form a resin layer (C). On top of this, a conductive ink containing 100 parts of nickel powder in 100 parts of acrylic resin (a volume resistivity value of the obtained film of 7.5 Ω · cm) was used, and a graphic unit like the graphic unit shown in FIG. Tie pattern length 12
mm, line width 200μm, number of line-shaped cord bands in one figure unit 3
2) Printing is performed so as to form a pattern in which the vertical, horizontal, and horizontal intervals between the graphic units are each 5 mm to form a pattern coating layer (A) having a film thickness of about 25 μm.
I got

Production Example 4 A non-woven fabric of aramid fiber having a thickness of about 100 μm was mixed with 100 parts of Epicoat 828 and 105 parts of a mixture of 5 parts of diethylenetetramine as a curing agent, with 5 parts of conductive carbon and 150 parts of barium titanate powder. And a coating containing 100 parts by weight of the coating composition was coated on a smooth metal plate so as to have a dry film thickness of 100 μm.
It was hot-pressed at 00 ° C. under a pressure of 50 kg / cm ² for 60 minutes to form a molded sheet having a thickness of about 100 μm, which is a resin layer (C). On another polyimide film [(B) layer: film thickness 25 μm], a copper foil having a thickness of 12 μm was laminated,
On top of this, a negative type photoresist Sonne EDUV376
(Manufactured by Kansai Paint Co., Ltd.) using an electrodeposition coating method
It was coated to a thickness of 0 μm, exposed to 100 mj / cm ² with an ultra-high pressure mercury lamp through a negative photomask in which squares each having a side of 15 mm were arranged in a checkered pattern, developed with 1% sodium carbonate water, and then exposed. Copper was removed with ferric chloride to form a metal pattern layer (A). The obtained thermocompression-bonded sheet is sandwiched between the (B) layer of the (B) layer having the (A) layer and the (C) layer, and is press-bonded while heating to 180 ° C. to obtain a laminate-4.
I got

Example 1 Between the layer (C) of the laminate-2 and the layer (A) of the laminate-1,
Between the (D) layer of the laminate-1 and the (A) layer of the laminate-4, and the (C) layer of the laminate-4 and an aluminum foil [(E) layer] having a thickness of 25 μm. The gaps were respectively bonded with an adhesive to obtain a radio wave antireflective body.

Example 2 Between the layer (D) of the laminated body-3 and the layer (A) of the laminated body-4,
The layer (C) of the laminate-4 and the copper foil ((E) layer) having a thickness of 12 μm were bonded to each other with an adhesive to obtain a radio wave antireflection body.

Example 3 Between the layer (D) of the laminated body-3 and the layer (A) of the laminated body-2,
Between the (C) layer of the laminate-2 and the (A) layer of the laminate-1, between the (D) layer of the laminate-1 and the (A) layer of the laminate-4, and Layer (C) of laminate-4 and thickness 25 μm
m and the aluminum foil [(E) layer] were bonded to each other with an adhesive to obtain a radio wave antireflection body.

Example 4 Urethane acrylate clear was applied on the uppermost layer (A) of the radio wave antireflective member of Example 1 to form a clear coating film having a dry film thickness of about 50 μm. 300mm x 300mm instead of aluminum foil (E) layer on body
A radio wave anti-reflection structure was prepared in the same manner as in Example 1 except that a structure having a metal surface which was a steel column of × 1,000 mm was used.

Comparative Example 1 Comparative Example 1 was a multi-unit laminate in which the aluminum foil (E) layer was removed from the anti-reflective member of Example 1.

Comparative Example 2 A paint containing 200 parts of barium-based ferrite with respect to 100 parts of an acrylic resin was applied on a polyimide film having a thickness of 25 μm and dried to a dry film thickness of 3 mm to form a ferrite-containing paint layer. A laminate in which a 25 μm-thick aluminum foil was adhered to the polyimide film side of this laminate was designated as Comparative Example 2.

Comparative Example 3 A laminate was formed in the same manner as in the laminate of Comparative Example 2, except that the dried film thickness of the ferrite-containing paint layer was changed to 1 mm. The polyimide film side and the ferrite-containing paint layer side of each of the three laminates are bonded with an adhesive,
Comparative Example 3 was a laminate in which three laminates were formed into a multi-layer, and an aluminum foil having a thickness of 25 μm was adhered to the polyimide film side of the multi-layer.

The anti-reflection effect of the anti-reflection member, anti-reflection structure and laminate (comparative example) obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was measured by the following method. The results are shown in Table 1 below. Examples 1 to 3
Table 1 shows the weight of the radio wave reflection preventive body and the laminates of Comparative Examples 1 to 3.
Shown in Table 1 shows the weight of the laminate to be bonded to the steel column for Example 4.

Measurement method of radio wave reflection prevention effect A transmitting horn antenna and a receiving horn antenna are connected to an incident radio wave in an anechoic chamber in which a radio wave absorber having a radio wave reflectance of 0.01% or less is attached to a wall surface of a room. Installed so that the angle with the reflected radio wave is 5 °, and 60 degrees from each antenna.
A metal reflector is placed at a distance of cm and the reflected signal is received by a receiving horn antenna, and its radio wave reflectance is set to 100%. Next, the measurement sample is placed in place of the metal reflection plate, and the maximum absorption frequency, the radio wave reflectance at the maximum absorption frequency, the effective absorption band (3 around the maximum absorption frequency) are obtained from the signals reflected from the measurement sample surface at various frequencies. %).

[0055]

[Table 1]

[0056]

As is clear from Examples 1 to 3 based on the present invention, the laminated type anti-reflective body of the present invention shows a very small value of the radio wave reflectance even if the film thickness is thin and light. ,
The effective absorption band is also wide. From the results of Comparative Example 1, when the radio wave reflector layer (E) was not present, a very high radio wave reflectance was exhibited, and there was substantially no effect as an anti-radio wave reflector. In order to lower the radio wave reflectance only with a film, a thick film is necessary, and only a ferrite film has a narrow effective absorption band. From the above, in the radio wave reflection preventing body of the present invention, a laminate in which a plurality of laminate units each including the pattern layer (A) and the resin layer (C) as essential components is laminated on the radio wave reflector layer (E). The structure formed by laminating the layers makes it possible to effectively prevent the reflection of radio waves by the unexpectedly special wave interference or cancellation of the wave energy between the laminate and the radio wave reflector layer (E). Also, in Example 4, which is the method of the present invention, in which a plurality of unit structures excluding the radio wave reflector layer (E) from the radio wave antireflection body of the present invention are formed on a radio wave reflecting structure having a metal surface, good radio waves are obtained. Has an anti-reflection effect.

[Brief description of the drawings]

FIG. 1 is an example of a graphic unit constituting a pattern layer (A) of a radio wave antireflection body of the present invention.

FIG. 2 is an example of a graphic unit constituting a pattern layer (A) of the radio wave reflection preventer of the present invention.

FIG. 3 is an example of a graphic unit constituting a pattern layer (A) of the radio wave reflection preventer of the present invention.

FIG. 4 is an example of a figure unit constituting the pattern layer (A) of the radio wave reflection preventer of the present invention.

FIG. 5 is an example of a figure unit constituting the pattern layer (A) of the radio wave antireflection body of the present invention.

FIG. 6 is an example of a graphic unit constituting the pattern layer (A) of the radio wave reflection preventer of the present invention.

FIG. 7 is an example of a graphic unit constituting the pattern layer (A) of the radio wave reflection preventer of the present invention.

FIG. 8 is an example of a graphic unit constituting the pattern layer (A) of the radio wave antireflection body of the present invention.

FIG. 9 is an example of a figure unit constituting the pattern layer (A) of the radio wave antireflection body of the present invention.

FIG. 10 is a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 11 is a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 12 is a pattern layer (A) of the radio wave antireflection body of the present invention.
5 is an example of an array pattern in graphic units in FIG.

FIG. 13 is a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 14 is a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 15 is a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 16 shows a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 17 is a pattern layer (A) of the radio wave antireflection body of the present invention.
FIG.

FIG. 18 is a pattern layer (A) of the radio wave antireflection body of the present invention.
Is an example of an array pattern in graphic units that constitutes.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-34701 (JP, A) JP-A-47-36830 (JP, A) JP-A-3-53594 (JP, A) JP-A-63-63 168093 (JP, A) JP-A-50-68249 (JP, A) JP-A-62-68731 (JP, A) JP-A-1-158799 (JP, A) JP-A-1-300596 (JP, A) JP-A-62-78899 (JP, A) JP-A-1-293699 (JP, A) JP-A-2-68497 (JP, U) JP-A-62-122396 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05K 9/00

Claims (7)

(57) [Claims] 1. A pattern layer (A) formed in a geometric pattern, a support layer (B) which may be interposed if necessary, a resin layer (C), and an interposition if necessary. Plural units formed by laminating a plurality of the laminate units such that the layer (A) side faces the layer (C) or the layer (D) side, with a laminate formed by sequentially laminating the support layer (D) as one unit. A radio wave antireflective body having a structure in which a laminate is laminated on a radio wave reflector layer (E) such that the layer (C) or layer (D) side of the multi-unit laminate faces the layer (E). Wherein all or at least one layer of the pattern layer (A) has a volume resistivity value of 10
A laminated type radio wave anti-reflective body, which is a pattern layer of a coating film having ^-3 to 10 ³ Ω · cm, wherein the layer (A) other than the pattern layer of the coating film is a metal pattern layer. 2. The radio wave anti-reflective body according to claim 1, wherein the pattern layer of the coating film is formed by applying a paint containing a film-forming resin and a conductive powder. 3. The resin layer (C) is made of ferrite, carbon,
3. The radio wave antireflective body according to claim 1, wherein the antireflective body contains at least one kind of powder selected from a metal powder and a conductive metal oxide and, if necessary, a high dielectric material. 4. The resin layer (C) is formed on paper, cloth, nonwoven fabric or porous sheet by applying at least one kind of powder selected from ferrite, carbon, metal powder and conductive metal oxide, and optionally having a high dielectric constant. The radio wave anti-reflective body according to claim 3, wherein a coating material obtained by dispersing a material in a binder is applied and then molded under pressure. 5. The radio wave reflection device according to claim 1, wherein a clear or colored coating layer is further provided on the uppermost pattern layer (A) of the radio wave reflection preventive body. Prevention body. 6. An anti-reflection method for radio waves, comprising forming the anti-reflection radio wave body according to claim 1 on a structure. 7. On a radio wave reflecting structure having a metal surface,
A method for preventing radio wave reflection, comprising forming a plurality of unit structures excluding the radio wave reflector layer (E) from the radio wave anti-reflective body according to any one of claims 1 to 5.