Radio wave reflector, method for manufacturing radio wave reflector, and method for constructing radio wave reflector

Abstract

The present invention relates to a radio wave reflector capable of protecting a conductor without impairing radio wave reflectivity. A radio wave reflector (11) is provided with: a conductive layer (16) including a conductor (12) that reflects radio waves; and a protective layer (15) that protects the conductive layer (16). When the radio wave reflector (11) is subjected to a pencil hardness test, the pencil hardness is F or more under the condition that the surface load on the protective layer (15) is 500 g.

Description

Technical Field

[0001] The present invention relates to a radio wave reflector. Background Art

[0002] In mobile phones or wireless communications, radio waves in a frequency band of about 3 GHz or more and about 300 GHz or less, called centimeter waves or millimeter waves, are used. Such radio waves with a short wavelength have a strong straight-forward property and are difficult to bypass obstacles. Therefore, in order to make the radio waves reach a wide range, reflectors are set on the surfaces of buildings such as walls, floors, ceilings, pillars, etc. (hereinafter referred to as "walls, etc.").

[0003] For example, Patent Document 1 describes a communication system in which a monopole antenna and a metal reflector for reflecting radio waves are arranged in an indoor underfloor space. The metal reflector diffuses radio waves output from the monopole antenna into the underfloor space, and prevents the radio waves from leaking out of the room (building) from the underfloor space or being absorbed by the floor portion of the building.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-258514 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] However, the conventional metal reflector is simply a reflector made of metal. In order to reflect radio waves more efficiently, the inventors of the present invention considered laminating a conductive layer having a conductor and a protective layer for protecting the conductive layer.

[0009] However, if the surface hardness of the protective layer is weak, the protection of the conductor may be insufficient, and the radio wave reflectivity may be impaired.

[0010] An object of the present invention is to provide a radio wave reflector that can protect a conductor without impairing radio wave reflectivity.

[0011] Technical means to solve technical problems

[0012] In order to achieve the above object, the present invention includes the following subjects.

[0013] Item 1. A radio wave reflector comprising:

[0014] a conductive layer including a conductor that reflects electric waves; and

[0015] a protective layer that protects the conductive layer,

[0016] When the radio wave reflector is subjected to a pencil hardness test, the pencil hardness under the condition that the surface load of the protective layer is 500 g is F or more.

[0017] Item 2. The radio wave reflector according to Item 1, wherein:

[0018] The thickness of the protective layer is greater than 38 μm.

[0019] Item 3. The radio wave reflector according to Item 1 or 2, wherein:

[0020] When the protective layer is subjected to a pencil hardness test, the pencil hardness under a condition where the surface load of the protective layer is 500 g is F or more.

[0021] Item 4. The radio wave reflector according to any one of Items 1 to 3, further comprising:

[0022] an adhesive layer, which is disposed between the conductive layer and the protective layer to bond the conductive layer and the protective layer,

[0023] The adhesive layer has a hydroxyl value of 5 mgKOH / g or more.

[0024] Item 5. The radio wave reflector according to any one of Items 1 to 4, further comprising:

[0025] an adhesive layer, which is disposed between the conductive layer and the protective layer to bond the conductive layer and the protective layer,

[0026] The acid value of the adhesive layer is 50 mgKOH / g or less.

[0027] Item 6. The radio wave reflector according to any one of Items 1 to 5, wherein

[0028] The moisture permeability of the protective layer at 40°C and 90% rh is 20 g / m 2 Less than 24 hours.

[0029] Item 7. The radio wave reflector according to any one of Items 1 to 6, wherein

[0030] The adhesive force of the protective layer to the adherend layer decreases by 50% or less after a heat and humidity resistance test.

[0031] Item 8. The radio wave reflector according to any one of Items 1 to 7, wherein

[0032] The total light transmittance of the radio wave reflector is greater than 70%.

[0033] Item 9. The radio wave reflector according to any one of Items 1 to 8, further comprising:

[0034] an adhesive layer, which is disposed between the conductive layer and the protective layer to bond the conductive layer and the protective layer,

[0035] In the radio wave reflector, the adhesive layer does not contain an ultraviolet ray inhibitor.

[0036] Item 10. The radio wave reflector according to any one of Items 1 to 9, wherein

[0037] The conductive layer has:

[0038] an area without said electrical conductor; and

[0039] the conductor being formed so as to surround the region,

[0040] The region includes a plurality of regions of the same shape,

[0041] The plurality of regions of the same shape are arranged at regular intervals.

[0042] Item 11. The radio wave reflector according to any one of Items 1 to 10, wherein

[0043] The surface resistivity of the radio wave reflector after the heat and humidity resistance test is 100Ω / □ or less.

[0044] Item 12. The radio wave reflector according to any one of Items 1 to 11, wherein

[0045] The protective layer contains at least one of an anti-ultraviolet agent and an anti-ultraviolet treatment is applied to the surface.

[0046] Item 13. The radio wave reflector according to any one of Items 1 to 12, wherein

[0047] The radio wave reflector has a haze of 30% or less.

[0048] Item 14. The radio wave reflector according to any one of Items 1 to 13, wherein

[0049] The total light transmittance of the radio wave reflector after the light resistance test is 70% or more.

[0050] Item 15. The radio wave reflector according to any one of Items 1 to 14, wherein

[0051] The yellowing degree Δb* of the radio wave reflector before and after the light resistance test is 15 or less.

[0052] Item 16. The radio wave reflector according to any one of Items 1 to 15, comprising: a laminate in which the protective layer and the conductive layer are laminated;

[0053] When viewed from above, all of the electrical conductors are covered by the protective layer.

[0054] Item 17. The radio wave reflector according to Item 16, wherein:

[0055] The laminate further comprises an adhesive layer for bonding the protective layer and the conductive layer.

[0056] The conductor is arranged inside the edge of the protective layer when viewed from above,

[0057] The conductor is covered by the adhesive layer when viewed from the side.

[0058] Item 18. The radio wave reflector according to Item 17, wherein:

[0059] The conductive layer further comprises a substrate supporting the conductor,

[0060] The conductor is located between the substrate and the protective layer, and is arranged on the inner side than the edge of the substrate when viewed from above.

[0061] Item 19. The radio wave reflector according to any one of Items 16 to 18, wherein

[0062] The conductor is arranged at an inner side of 5 mm or more from an edge of the protective layer when viewed from above.

[0063] Item 20. The radio wave reflector according to any one of Items 16 to 19, wherein

[0064] A sealing material is provided at least at a position corresponding to the conductive layer around the laminate so as to prevent the conductive body from being exposed.

[0065] Item 21. The radio wave reflector according to any one of Items 16 to 20, wherein

[0066] The difference between the yellowness index after the heat and humidity resistance test and the yellowness index before the heat and humidity resistance test is 3 or less,

[0067] The heat and humidity resistance test is a test in which the radio wave reflector is placed in a constant temperature and humidity chamber adjusted to a temperature of 60° C. and a humidity of 95% RH for 500 hours, the radio wave reflector is taken out of the chamber, and left to stand at room temperature for 4 hours.

[0068] Item 22. The radio wave reflector according to any one of Items 1 to 21, wherein

[0069] When an incident wave with a frequency of 3 GHz to 300 GHz is orthographically reflected by the radio wave reflector after the heat and humidity resistance test and the radio wave reflector before the heat and humidity resistance test, there is at least one frequency of the incident wave such that the difference between the intensity of the reflected wave by the radio wave reflector after the heat and humidity resistance test and the intensity of the reflected wave by the radio wave reflector before the heat and humidity resistance test is within 3 dB,

[0070] The heat and humidity resistance test is a test in which the radio wave reflector is placed in a constant temperature and humidity chamber adjusted to a temperature of 60° C. and a humidity of 95% RH for 500 hours, the radio wave reflector is taken out of the chamber, and left to stand at room temperature for 4 hours.

[0071] Item 23. A method for manufacturing a radio wave reflector, which is the method for manufacturing a radio wave reflector according to Item 20, wherein:

[0072] The manufacturing method comprises:

[0073] a step of forming the laminate; and

[0074] A step of providing a sealing material for preventing the conductor from being exposed,

[0075] The sealing material of the radio wave reflector is located at a position around the laminate at least corresponding to the conductive layer.

[0076] Item 24. A method for constructing a radio wave reflector, which is the method for constructing a radio wave reflector according to Item 20, wherein:

[0077] The construction method comprises:

[0078] A step of installing the laminate at a location; and

[0079] A step of providing a sealing material for preventing the conductor from being exposed,

[0080] The sealing material of the radio wave reflector is located at a position around the laminate at least corresponding to the conductive layer.

[0081] Item 25. The method for constructing a radio wave reflector according to Item 24, wherein:

[0082] In the installation step, a plurality of the stacked bodies are installed at a location at intervals.

[0083] In the step of providing the sealing material, the sealing material is provided in a space between adjacent stacked bodies when the plurality of stacked bodies are installed at a location with a certain interval therebetween.

[0084] Effects of the Invention

[0085] The radio wave reflector of the aspect of the present invention has the advantage of being able to protect the conductor without impairing the radio wave reflectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] [ Figure 1 ] Figure 1 It is a schematic diagram for explaining the angle range of the reflected wave reflected by the radio wave reflector according to the embodiment.

[0087] [ Figure 2 ] Figure 2 This is a schematic cross-sectional view of a radio wave reflector according to an embodiment.

[0088] [ Figure 3 ] Figure 3 (A) is a schematic plan view of the entire radio wave reflector according to the embodiment. Figure 3 (B) is an enlarged view of part A of (A).

[0089] [ Figure 4 ] Figure 4 yes Figure 3 (A) Magnified view of part C.

[0090] [ Figure 5 ] Figure 5 (A) to (E) are schematic plan views showing variations of the arrangement patterns of the conductors.

[0091] [ Figure 6 ] Figure 6 (A) is an explanatory diagram showing a usage example of the radio wave reflector according to the embodiment. Figure 6 (B) is a schematic plan view showing an example of indoor application of the building material.

[0092] [ Figure 7 ] Figure 7 (A) is a schematic plan view of the entire radio wave reflector according to another embodiment. Figure 7 (B) is a schematic cross-sectional view of a part of a radio wave reflector according to another embodiment.

[0093] [ Figure 8 ] Figure 8 It is a schematic plan view of the entire radio wave reflector according to another embodiment.

[0094] [ Fig. 9 ] Fig. 9 This is a schematic cross-sectional view of a radio wave reflector according to Modification 1.

[0095] [ Fig.10 ] Fig.10 This is a schematic cross-sectional view of a radio wave reflector according to Modification 2.

[0096] [ Fig.11 ] Fig.11(A) is a schematic plan view of a radio wave reflector according to Modification 3. Fig.11 (B) Yes Fig.11 (A) Magnified view of part B.

[0097] [ Fig.12 ] Fig.12 (A) is a schematic plan view of a radio wave reflector according to Modification 4. Fig.12 (B) Yes Fig.12 (A) Magnified view of part B. DETAILED DESCRIPTION

[0098] <Implementation Method>

[0099] (Overall Structure of Radio Wave Reflector 11)

[0100] Embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown in FIG. 1 , the radio wave reflector 11 of this embodiment is a sheet-like member capable of reflecting radio waves. The radio wave reflector 11 is configured to reflect radio waves output from the radio wave generating unit 20, for example. The radio waves reflected by the radio wave reflector 11 are received by the receiving unit 21. Figure 2 As shown, the radio wave reflector 11 includes a conductive layer 16 including a conductor 12, an adhesive layer 14, and a protective layer 15 laminated in this order.

[0101] The term "sheet" as used in this specification refers to a shape in which the thickness of the object is 10% or less relative to the maximum length between the outer edges of the top view. When the shape of the top view is rectangular, the "maximum length between the outer edges of the top view" refers to the length of the diagonal. In addition, when the shape of the top view is circular, the "maximum length between the outer edges of the top view" refers to the length of the diameter. In this specification, films, foils, thin films, etc. are also included in the "sheet".

[0102] The radio wave generator 20 is a device that outputs radio waves. The radio wave generator 20 of this embodiment is a communication device having a transmission antenna that can output a wireless signal using radio waves as a medium. Examples of the radio wave generator 20 include: a fixed base station, a mobile base station, a radio wave transmitter, a wireless terminal, and the like.

[0103] The receiving unit 21 is a device capable of receiving radio waves. The receiving unit 21 of this embodiment is a communication device having a receiving antenna. Examples of the receiving unit 21 include a smartphone, a mobile phone, a tablet terminal, a notebook PC, a portable game console, a repeater, a radio, a television, and the like.

[0104] The radio wave reflector 11 of the present embodiment can reflect radio waves, for example, the frequency of the incident wave belongs to any range of 3 GHz or more and 5 GHz or less, 25 GHz or more and 30 GHz or less, and 100 GHz or more and 300 GHz or less. The "radio wave that can be reflected" mentioned here refers to a radio wave having at least one intensity of any incident wave with an incident angle of 15 degrees or more and 75 degrees or less, and the intensity of the outgoing wave after regular reflection (sometimes referred to as "regular reflection intensity") is -30 dB or more and 0 dB or less. Preferably, for any incident wave with an incident angle of 15 degrees or more and 75 degrees or less, the regular reflection intensity is -30 dB or more and 0 dB or less.

[0105] More specifically, at a frequency of 28.5 GHz, the regular reflection intensity is preferably above -30 dB and below 0 dB relative to the incident wave, more preferably in all frequency bands above 20 GHz and below 60 GHz, the regular reflection intensity is preferably above -30 dB and below 0 dB relative to the incident wave, and further preferably in all frequency bands above 3 GHz and below 300 GHz, the regular reflection intensity is preferably above -30 dB and below 0 dB relative to the incident wave.

[0106] The attenuation of the regular reflection intensity relative to the incident wave is preferably smaller. The regular reflection intensity relative to the incident wave is preferably -25dB to 0dB, more preferably -22dB to 0dB, further preferably -20dB to 0dB, further preferably -15dB to 0dB.

[0107] By making the regular reflection intensity relative to the incident wave more than -30dB, the radio wave reflector 11 can reflect the radio wave while maintaining the reflection intensity. As a result, the receiving unit 21 can receive the radio wave with practical intensity. The "reflection intensity" and "regular reflection intensity" in this specification refer to the intensity when the distance between the reflection point 11a and the measurement point is 1m. In addition, the regular reflection intensity is measured in the state where the radio wave reflector 11 is not bent or folded but made into a plane.

[0108] like Figure 3 As shown, the radio wave reflector 11 of this embodiment is a quadrilateral (including a square and a rectangle) in a top view. The length L10 of one side of the radio wave reflector 11 is, for example, preferably 20 cm or more, more preferably 100 cm or more, and further preferably 200 cm or more. On the other hand, the upper limit of the length L10 of one side of the radio wave reflector 11 is not particularly limited, for example, 400 cm or less. If the length L10 of one side is 20 cm or more, it is easy to reflect radio waves with sufficient intensity.

[0109] The shape of the radio wave reflector 11 is not limited to a quadrilateral, and can be, for example, a geometric shape such as a triangle, a pentagon, a hexagon, a circle, an ellipse, or a non-geometric shape. In the radio wave reflector 11, the size of the maximum value in the distance between the ends is preferably more than 20 cm and less than 400 cm. The "size of the maximum value in the distance between the ends" refers to the size of the diagonal when the radio wave reflector 11 is a rectangle, refers to the size of the diameter when the radio wave reflector 11 is a circle, and refers to the length of the major axis when the radio wave reflector 11 is an ellipse.

[0110] The thickness L1 of the radio wave reflector 11 is preferably 0.01 mm or more, more preferably 0.05 mm or more, and further preferably 0.2 mm or more. On the other hand, the upper limit of the thickness L1 of the radio wave reflector 11 is preferably 0.5 mm or less, and more preferably 0.4 mm or less. When the thickness L1 of the radio wave reflector 11 is 0.01 mm or more, it is possible to maintain strength while having flexibility. When the thickness L1 of the radio wave reflector 11 is 0.5 mm or less, when the radio wave reflector 11 is bent, it is not easy to bend, and as a result, stress concentration is not easy to occur in the conductor 12. The "bending" mentioned here refers to bending accompanied by plastic deformation in any layer of the radio wave reflector 11.

[0111] When the electric wave reflector 11 is subjected to a pencil hardness test, the pencil hardness under the condition that the surface load of the protective layer 15 is 500g is preferably "F" or more, more preferably "H" or more, and further preferably "4H" or more. The "pencil hardness test" mentioned in this specification is a test based on JIS K5600-5-4 (1999). In addition, as for "surface load 500g", if the load applied to the surface during the pencil hardness test is 500g±10g, it is also included.

[0112] In addition, after the radio wave reflector 11 is subjected to the heat and humidity resistance test, the reduction rate of the adhesive force of the protective layer 15 to the bonded layer is preferably 50% or less, more preferably 45% or less, and further preferably 40% or less. The "bonded layer" mentioned in this specification refers to a layer that is in direct contact with the target layer. In this embodiment, the bonded layer of the protective layer 15 is the adhesive layer 14. The adhesive force is measured by a tensile adhesive strength test based on JIS K6849 (1994).

[0113] The heat and humidity resistance test is a test in which the radio wave reflector 11 is placed in a constant temperature and humidity chamber adjusted to a temperature of 60°C and a humidity of 95% rh (relative humidity), left to stand for 500 hours, the radio wave reflector 11 is taken out of the constant temperature and humidity chamber, left to stand at room temperature for 4 hours, and changes in properties are confirmed.

[0114] The difference between the intensity of the reflected wave of the radio wave reflector 11 after the heat and humidity test and the intensity of the reflected wave of the radio wave reflector 11 before the heat and humidity test is preferably within 3dB. The incident angle of the incident wave for which the difference in the intensity of the reflected wave before and after the heat and humidity test is within 3dB preferably exists at least at one angle of 15 degrees or more and 75 degrees or less, more preferably 45 degrees, and more preferably all angles in the range of angles of 15 degrees or more and 75 degrees or less. The frequency of the incident wave for which the difference in the intensity of the reflected wave before and after the heat and humidity test is within 3dB preferably exists at least one between 3GHz or more and 300GHz or less, and more preferably all frequencies in the frequency band of 3GHz or more and 300GHz or less.

[0115] In addition, in the radio wave reflector 11, the surface resistivity after the heat and humidity resistance test is preferably 100Ω / □ or less, more preferably 50Ω / □ or less, and further preferably 20Ω / □ or less. By having a surface resistivity of 20Ω / □ or less after the heat and humidity resistance test, the radio wave reflector 11 does not lose its reflection strength even if it is left in a high temperature and high humidity environment for a long time, and can maintain the radio wave reflector 11 with practicality.

[0116] The surface resistivity of the radio wave reflector 11 before the heat and humidity resistance test is preferably 0.003Ω / □ to 10Ω / □, more preferably 0.01Ω / □ to 9Ω / □, and further preferably 0.02Ω / □ to 8Ω / □. It should be noted that the surface resistivity is a value measured when the radio wave reflector 11 is placed on a placement surface consisting of a flat surface.

[0117] The change rate of the surface resistivity of the radio wave reflector 11 after the heat and humidity resistance test relative to that before the heat and humidity resistance test is preferably 20% or less, more preferably 17% or less, and further preferably 15% or less. If the surface resistivity before the heat and humidity resistance test is set to r1 and the surface resistivity before the heat and humidity resistance test is set to r2, the change rate r is calculated by r=(r1-r2) / r1×100.

[0118] The reflection intensity of radio waves varies according to the surface resistivity. If the change rate r of the surface resistivity of the wave reflector 11 is small, the reflection intensity is not easy to decrease. The change rate r of the surface resistivity of the radio wave reflector 11 during the heat and humidity resistance test is 20% or less. Therefore, even after the heat and humidity resistance test, the reflection intensity of the radio wave reflector 11 does not decrease significantly, and sufficient reflection intensity of radio waves can be achieved.

[0119] In addition, for the radio wave reflector 11, the rate of change of the surface resistivity before and after the radio wave reflector 11 is bent along the surface of a member having a curvature radius of 200 mm (also referred to as "the rate of change of the surface resistivity during bending") R may be -10% or more and 10% or less. The rate of change of the surface resistivity during bending R refers to the ratio of the change of the surface resistivity R2 of the radio wave reflector 11 in the state where the radio wave reflector 11 is bent along the surface of a member having a curvature radius of 200 mm relative to the surface resistivity R1 of the radio wave reflector 11 in the state where the radio wave reflector 11 is flat. The rate of change of the surface resistivity R is obtained by R = (R2-R1) / R1×100.

[0120] The reflection intensity of radio waves varies according to the surface resistivity. The change rate R of the surface resistivity when the radio wave reflector 11 is bent is between -10% and 10%, so even when the radio wave reflector 11 is bent, sufficient reflection intensity of radio waves can be achieved as in a flat state.

[0121] In this specification, surface resistivity refers to the 2 The surface resistivity can be measured by a four-terminal method in accordance with JIS K 6911 by bringing the measuring terminal into contact with the surface of the conductive layer. It should be noted that the surface resistivity is measured as the surface resistivity of the conductor 12 of the conductive layer 16. When the conductor 12 of the conductive layer 16 is not exposed by protection with a resin sheet or the like, it can be measured by an eddy current method using a non-contact resistance measuring instrument (manufactured by NAPSON Co., Ltd., trade name: EC-80P or its equivalent).

[0122] The radio wave reflector 11 preferably has visible light transmittance as a whole. That is, the radio wave reflector 11 is preferably transparent. The conductive layer 16, the adhesive layer 14 and the protective layer 15 can be formed of a material having visible light transmittance and / or a thickness having visible light transmittance. Here, "transparent" means that an object located on one side of the radio wave reflector 11 can be visually recognized by observing it from the other side, and the total light transmittance may not be 100%. "Transparent" includes translucency. In addition, the radio wave reflector 11 may also be colored.

[0123] The total light transmittance of the radio wave reflector 11 is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more. In this specification, "total light transmittance" refers to the transmittance of light from a D65 standard light source. The total light transmittance is measured in accordance with JIS K 7375 (2008). After the light resistance test described below, the total light transmittance of the radio wave reflector 11 is also preferably 70% or more, more preferably 75% or more, and further preferably 80% or more.

[0124] The haze of the radio wave reflector 11 is preferably 30% or less. Haze refers to the degree of cloudiness of the radio wave reflector 11 and is defined in JIS-K7136: 2000. In particular, after a light resistance test, the haze is preferably 30% or less.

[0125] The light resistance test is as follows: The radio wave reflector 11 is placed in a tank of a measuring device (for example, Xenon Sunshine Weather Ometer Ci4000 manufactured by ATLAS). The irradiance in the tank is set to 60 W / m 2 (300-400nm), black standard temperature (BST) 65±3°C, humidity 50±5%RH, tank temperature 38°C, irradiation with light (direct sunlight for 1 year) for 1300 hours, and confirm the change in the properties of the radio wave reflector 11.

[0126] The yellowing degree Δb* of the radio wave reflector 11 before and after the light resistance test is preferably 15 or less. The yellowing degree Δb* refers to the difference (b*2-b*1) between the intensity b*1 of the hue (yellow) of +b* before the light resistance test and the intensity b*2 of the hue (yellow) of +b* after the light resistance test in the L*a*b* color system defined by CIE (International Commission on Illumination). The larger the value, the stronger the color change to yellow. If the yellowing degree Δb* is 15 or less, it is not easy to visually recognize the change of the radio wave reflector 11 to yellow, and the influence of discoloration and deterioration is small. The yellowing degree Δb* is measured according to JIS Z 8781-4.

[0127] The difference between the yellow index after the heat and humidity resistance test of the radio wave reflector 11 and the yellow index before the heat and humidity resistance test is 3 or less. The yellow index is also called yellowness, which refers to the degree of deviation of the color tone from colorless or white to the yellow direction. The yellow index is obtained by a method based on JISK7373:2006. The difference in the yellow index is an index for evaluating yellowing, which is one of the deterioration phenomena of the radio wave reflector 11. The smaller the difference in the yellow index, the smaller the deterioration. The yellow index is different from the yellowing degree Δb*, and the yellow index is obtained using the XYZ color system defined by CIE (International Commission on Illumination).

[0128] The bending elastic modulus of the radio wave reflector 11 is preferably 0.05 GPa or more and 4 GPa or less. By setting the bending elastic modulus to be within the above range, the radio wave reflector 11 is flexible, and the radio wave reflector 11 can be bent and pasted on a curved surface or a spherical surface without bending or breaking the radio wave reflector 11. The bending elastic modulus is measured according to JIS K7171. In this specification, "flexibility" refers to the property of bending without breaking or plastic deformation at room temperature and pressure.

[0129] The longitudinal elastic modulus of the radio wave reflector 11 is preferably 0.01 GPa or more and 80 GPa or less. By setting the longitudinal elastic modulus to be within the above range, the radio wave reflector 11 is easily deformed, and the radio wave reflector 11 can be bent and attached to a curved surface with a curvature radius of 200 mm or more without breaking the radio wave reflector 11. The longitudinal elastic modulus is also called Young's modulus or tensile elastic modulus, which is defined by JIS K7161-2014 and measured according to JIS K 7127 (1999).

[0130] The radio wave reflector 11 of the present embodiment has flexibility to the extent that it can be attached along a curved surface having a curvature radius of at least 200 mm, and preferably has flexibility to the extent that it can be attached along a curved surface having a curvature radius of at least 100 mm.

[0131] The radio wave reflector 11 may also have plasticity. Plasticity refers to the property that it can be deformed by applying external pressure, and when a deformation exceeding the elastic limit is applied by pressure, the deformed shape is maintained even when the force is removed. The conductive layer 16, the adhesive layer 14, and the protective layer 15 may all have plasticity, or at least one of the conductive layer 16, the adhesive layer 14, and the protective layer 15 may have plasticity.

[0132] The surface roughness Sa of the conductor 12 is not particularly limited, but is preferably 1 μm to 7 μm, and more preferably 1.03 μm to 6.72 μm. When the surface roughness Sa is within this range, radio waves can be easily diffused and reflected.

[0133] The surface roughness Sa is obtained by the arithmetic mean height of ISO 25178 and is measured according to ISO 25178. The surface roughness Sa of the conductor 12 can be obtained by measuring the surface roughness at multiple locations on the surface of the conductor 12 using a laser microscope (product name VK-X1000 / 1050, manufactured by KEYENCE or its equivalent) and calculating the average value of the obtained measured values.

[0134] In addition, if Figure 1 As shown, the radio wave reflector 11 preferably makes the receiving angle position of the reflected wave relative to the reflected wave A2 of the regular reflection change within the angle range α of more than -15 degrees and less than +15 degrees in the imaginary plane containing the incident wave A1 and the reflected wave, and the peak of the distribution of the intensity of the reflected wave at each receiving angle position is less than -0.4. The peak is more preferably less than -1.0, further preferably less than -1.1, and further preferably less than -1.2. The lower limit of the peak is not particularly limited, for example, more than -0.5. The reflection point 11a on the reflection surface of the radio wave reflector 11, the radio wave generation source 20, and the receiving unit 21 of the reflected wave are located on the imaginary plane. The measurement of the peak is carried out when the radio wave reflector 11 is set to a planar state.

[0135] Kurtosis is a statistic that indicates how much a distribution deviates from a normal distribution, indicating the sharpness of the peak and the spread of the lower hem. Figure 1 As shown, the radio wave output from the radio wave generating source 20 is incident on the radio wave reflector 11 at an incident angle θ1 and is reflected at an outgoing angle θ2. The receiving angle position i of the receiving unit 21 is moved within an angle range α of not less than -15 degrees and not more than +15 degrees with respect to the reflected wave A2 after the regular reflection of the radio wave, with the reflection point 11a as the center, at a given angle (for example, every 5 degrees), and the reflection intensity x is measured. The receiving angle position i of the receiving unit 21 is located on an arc with the reflection point 11a as the center. The value x of the reflection intensity at each receiving angle position i is i The average value of (i: 1, 2, ..., n) is set to , when the standard deviation is set to s, the kurtosis is calculated by the following formula.

[0136] [Mathematical formula 1]

[0137]

[0138] As for the kurtosis, a negative value indicates that the intensity data at each angular position is flatter than the normal distribution, that is, the downward swing of the data from the vicinity of the average value is expanded, and the smaller the kurtosis value, the flatter the distribution. In this embodiment, by setting the kurtosis to be less than -0.4, the difference in reflection intensity based on the receiving angle position becomes smaller within the angle range α of ±15 degrees relative to the reflected wave of the regular reflection.

[0139] (Configuration of Each Layer of Radio Wave Reflector 11)

[0140] Hereinafter, each layer of the radio wave reflector 11 will be described in more detail. In the following description, the overlapping direction of a plurality of layers is defined as the "up-down direction". In addition, when the radio wave reflector 11 is observed in the up-down direction, "longitudinal direction" and "lateral direction" are defined. However, the definitions of these directions are only for explanation and do not limit the use. In addition, each figure is only a schematic diagram and does not represent a strict scale.

[0141] like Figure 2 As shown in the figure, the radio wave reflector 11 includes a laminated body 18 in which a plurality of layers are laminated. The laminated body 18 includes a conductive layer 16 including a conductor 12 for reflecting radio waves and a protective layer 15 for protecting the conductive layer 16. The laminated body 18 may further include an adhesive layer 14 including an adhesive for bonding the conductive layer 16 to the protective layer 15. In this embodiment, the radio wave reflector 11 includes an adhesive layer 14 and a protective layer 15 laminated in this order on the conductor 12 of the conductive layer 16.

[0142] (Conductive layer 16)

[0143] The conductive layer 16 is a layer having the conductor 12. The conductive layer 16 includes a substrate 13 and the conductor 12 for reflecting radio waves. The conductor 12 is located between the substrate 13, the adhesive layer 14, and the protective layer 15. It should be noted that the conductive layer 16 may also be composed of the conductor 12 without including the substrate 13. In this case, the protective layer 15 supports the conductor 12 as the substrate 13.

[0144] (Substrate 13)

[0145] The substrate 13 supports the conductor 12. In the present embodiment, the outer shape of the substrate 13 is formed into a rectangular shape (more specifically, a square shape) in a top view. The substrate 13 is formed with a uniform thickness over the entire surface. The substrate 13 may also have a non-uniform thickness, for example, may be formed into a wedge shape, or may be formed into a three-dimensional shape having a spherical surface or a concave-convex shape in part.

[0146] As the substrate 13, for example, synthetic resin, FRP (Fiber Reinforced Plastics), carbon, glass, etc. can be cited. As the synthetic resin, for example, one or more selected from PET (polyethylene terephthalate), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyester, polyoxymethylene, polyamide, polyphenylene ether, vinylidene chloride, polyvinyl acetate, polyvinyl acetal, AS resin, ABS resin, acrylic resin, fluororesin, nylon resin, polyacetal resin, polycarbonate resin, polyamide resin, and polyurethane resin can be cited. As the substrate, it can also be a composite material of these synthetic resins. The substrate 13 of the present embodiment is composed of a PET sheet.

[0147] The thickness L2 of the substrate 13 is, for example, preferably 15 μm or more, more preferably 20 μm or more, and further preferably 25 μm or more. On the other hand, the upper limit of the thickness L2 of the substrate 13 is, for example, preferably 200 μm or less, more preferably 150 μm or less, and further preferably 125 μm or less.

[0148] The substrate 13 is preferably flexible. The substrate 13 preferably has a higher longitudinal elastic modulus than the protective layer 15. The longitudinal elastic modulus of the substrate 13 is, for example, preferably 1 GPa or more, more preferably 1.2 GPa or more, and further preferably 1.5 GPa or more. On the other hand, the upper limit of the longitudinal elastic modulus of the substrate 13 is, for example, preferably 4 GPa or less, more preferably 3.8 GPa or less, and further preferably 3.5 GPa or less.

[0149] (Conductor 12)

[0150] The conductor 12 is a conductor that reflects radio waves. The conductor 12 is formed on the upper surface of the substrate 13. The conductor 12 is formed, for example, by wet etching or dry etching. As wet etching, for example, screen printing, photolithography, offset printing, etc. can be cited. Examples of dry etching include reactive gas etching, reactive ion etching, reactive ion beam etching, ion beam etching, and reactive laser beam etching.

[0151] In addition, the conductor 12 may be embedded in a resin to form a thin film. For example, after the conductor film is formed, a pattern may be formed by etching, and the conductive film having the pattern may be taken out. In addition, a photosensitive resist may be applied to a base film provided with a release layer, a pattern may be formed by photolithography, and after the conductor is filled in the pattern portion, the conductive film having the pattern may be taken out. In addition, the conductor 12 may be bonded with a metal film, or a metal may be evaporated.

[0152] When the thin film conductor 12 is used, the thin film (conductive film layer) including the conductor 12 is stacked on the base material 13 to form the conductive layer 16 .

[0153] As the conductor 12, for example, one or more of silver, gold, copper, platinum, aluminum, titanium, polysiloxane, indium tin oxide, and alloys (for example, alloys containing nickel, chromium, and molybdenum) can be cited. As alloys containing nickel, chromium, and molybdenum, for example, various grades of Hastelloy B-2, B-3, C-4, C-2000, C-22, C-276, G-30, N, W, and X can be cited.

[0154] The thickness L3 of the conductor 12 is preferably 5 nm or more, more preferably 0.05 μm or more. On the other hand, the upper limit of the thickness L3 of the conductor 12 is preferably 10 μm or less. When the thickness L3 of the conductor 12 is 5 nm or more, appropriate radio wave intensity can be ensured.

[0155] The coverage of the conductive layer 16 is preferably 1% or more and 50% or less, and more preferably 1% or more and 10% or less. The coverage refers to the ratio of the area occupied by the conductor 12 per unit area in the region where the conductor 12 is provided on the upper surface of the substrate 13 in a top view. The region where the conductor 12 is provided refers to the region obtained by removing the peripheral end portion of the substrate 13 (the portion between the end edge 13a of the substrate 13 and the conductor 12) from the upper surface region of the substrate 13. The coverage is measured using a scanning electron microscope (SEM), a transmission electron microscope (TEM), an optical microscope, or the like.

[0156] like Figure 3As shown in (B), the pattern of the conductor 12 is composed of a plurality of regions without the conductor 12 (here, sometimes referred to as "first regions 12a") and the conductor 12 surrounding the first regions 12a. The first regions 12a may be filled with a portion of the adhesive layer described later or with a resin forming the conductive layer 16. The plurality of first regions 12a are formed in the same shape, which is a square in this embodiment or a rectangular shape. The plurality of first regions 12a of the same shape are arranged at a certain interval.

[0157] More specifically, the conductor 12 of this embodiment is such that the first region 12a is surrounded by a rectangular conductor 12 composed of two parallel first linear bodies 12A and two parallel second linear bodies 12B. The first linear bodies 12A and the second linear bodies 12B are orthogonal to each other.

[0158] The common linear bodies 12A and 12B are located between the adjacent first regions 12a. The intersections of the first linear body 12A and the second linear body 12B are electrically connected. The width L6 of the linear body is preferably set to be greater than or equal to 0.05 μm and less than or equal to 15 μm.

[0159] The maximum length L7 between the edges in the first region 12a, or the interval L8 between the adjacent first linear bodies 12A and the adjacent second linear bodies 12B is set to be greater than the wavelength of visible light and less than the wavelength of the radio wave reflected by the radio wave reflector 11. The maximum length of the side of the first region 12a is preferably set to be greater than 2 μm and less than 10 cm, more preferably greater than 20 μm and less than 1 cm, further preferably greater than 25 μm and less than 1 mm, and further preferably greater than 30 μm and less than 250 μm. Thus, the maximum length L7 can be greater than the wavelength of visible light and less than the wavelength of the radio wave reflected by the radio wave reflector 11.

[0160] The thickness (L2+L3) of the conductive layer 16 is determined by the thickness of the substrate 13. The thickness (L2+L3) of the conductive layer is preferably 0.1 μm or more, more preferably 0.2 μm or more, and further preferably 0.3 μm or more. On the other hand, the upper limit of the thickness (L2+L3) of the conductive layer is preferably 20 μm or less, more preferably 15 μm or less, and further preferably 10 μm or less.

[0161] It should be noted that the details of the arrangement of the conductor 12 at the end of the radio wave reflector 11 will be described later.

[0162] (Modification of Pattern of Conductor 12)

[0163] The pattern of the conductor 12 is not limited to the lattice pattern as in the embodiment, and may be, for example, Figure 5(A) to (E) are patterns as shown. It should be noted that, for the purpose of illustration, Figure 5 (A)~ Figure 5 (E) shows only the conductor 12. The other conductors 12 are configured similarly to Figure 3 (B) The same.

[0164] In a variation, if Figure 5 As shown in (A), a brick-laying pattern is also possible. That is, a plurality of first linear bodies 12A are arranged in a straight line in the horizontal direction, and the first linear bodies 12A arranged in a straight line are arranged at intervals in the vertical direction. The second linear bodies 12B connect the first linear bodies 12A adjacent in the vertical direction, and the second linear bodies 12B adjacent in the vertical direction are staggered.

[0165] In a variation, if Figure 5 As shown in (B), it can also be a triangular pattern. In this modified example, as multiple areas without the conductor 12, there are a first area 12a with a triangular shape and a second area 12b with an inverted triangular shape. The second area 12b is arranged between adjacent first areas 12a. The first area 12a and the second area 12b are respectively surrounded by a first linear body 12A, a second linear body 12B and a third linear body 12C. Multiple first areas 12a are arranged at certain intervals in the horizontal and vertical directions. In addition, multiple second areas 12b are also arranged at certain intervals in the horizontal and vertical directions. Moreover, the shapes formed by the first area 12a and the second area 12b are arranged in the same period.

[0166] It should be noted that each of the regions 12 a and 12 b has a shape of an equilateral triangle, but may also be an isosceles triangle or a triangle with three sides of different lengths, for example.

[0167] In a variation, if Figure 5 As shown in (C), the first region 12a may be a regular hexagonal region surrounded by the linear conductor 12. A plurality of first regions 12a are arranged at regular intervals in the vertical and horizontal directions.

[0168] In a variation, if Figure 5As shown in (D), there may also be a plurality of regions without the conductor 12 of different shapes. That is, in one variation, as regions without the conductor 12, there are a first region 12a of a regular pentagon surrounded by a linear conductor 12, a second region 12b of an inverse regular pentagon, and a third region 12c of a rhombus. A plurality of first regions 12a are arranged at a certain interval in the horizontal and vertical directions. In addition, a plurality of second regions 12b are also arranged at a certain interval in the horizontal and vertical directions. In addition, a plurality of third regions 12c are also arranged at a certain interval in the horizontal and vertical directions. Furthermore, the shape composed of the first region 12a, the second region 12b, and the third region 12c is arranged in the same period.

[0169] In a variation, it may also be as follows Figure 5 That is, as the region without the conductor 12, a circular first region 12a surrounded by the linear conductor 12, a substantially triangular second region 12b, and a substantially inverted triangular third region 12c may be provided.

[0170] (Adhesive layer 14)

[0171] The adhesive layer 14 is provided between the conductive layer 16 and the protective layer 15 to bond the conductive layer 16 and the protective layer 15. As the adhesive layer 14, it is preferably provided over the entire surface between the conductive layer 16 and the protective layer 15, or it may be provided only on a portion between the conductive layer 16 and the protective layer 15. As the adhesive layer 14, for example, adhesive sheets made of synthetic resins and rubbers may be cited. As synthetic resins, for example, acrylic resins, polysiloxane resins, polyvinyl alcohol resins, etc. may be cited. As the adhesive layer 14, it may be formed by filling a fluid adhesive between the conductive layer and the protective layer and curing it, or an adhesive sheet having an adhesive surface may be arranged between the conductive layer 16 and the protective layer 15.

[0172] The thickness L4 of the adhesive layer 14 is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. The upper limit of the thickness L4 of the adhesive layer 14 is preferably 150 μm or less, more preferably 125 μm or less, and further preferably 100 μm or less.

[0173] In addition, the hydroxyl value of the adhesive layer 14 is preferably 5 mgKOH / g or more, more preferably 8 mgKOH / g or more, further preferably 30 mgKOH / g or more, and further preferably 90 mgKOH / g or more. On the other hand, the upper limit of the hydroxyl value of the adhesive layer 14 is preferably 120 mgKOH / g or less. When the hydroxyl value of the adhesive layer 14 is 5 mgKOH / g or more, there is an advantage that the adhesive layer 14 is not easy to bubble or / and whiten under a high temperature and high humidity environment. In this specification, the hydroxyl value is measured by a test method based on JIS K 1557.

[0174] In addition, the acid value of the adhesive layer 14 is preferably 50 mgKOH / g or less, more preferably 45 mgKOH / g or less, further preferably 30 mgKOH / g or less, and further preferably 10 mgKOH / g or less. On the other hand, the lower limit of the acid value of the adhesive layer 14 is preferably 0.1 mgKOH / g or more. When the acid value of the adhesive layer 14 is 50 mgKOH / g or less, the conductor 12 can be prevented from being corroded, and the time stability of the radio wave reflectivity can be improved. In this specification, the acid value is measured by the test method according to JIS K 2501.

[0175] The adhesive layer 14 preferably does not contain an anti-ultraviolet agent. If the adhesive layer 14 does not contain an anti-ultraviolet agent, it is easy to adjust the adhesive layer 14 to be colorless and transparent. Here, "does not contain" includes not only the case where the anti-ultraviolet agent is not contained at all, but also the case where the adhesive layer 14 contains a trace amount of anti-ultraviolet agent to the extent that the colorless and transparent property is not impaired. The anti-ultraviolet agent absorbs or scatters ultraviolet rays to prevent the invasion of ultraviolet rays, and can be any of an ultraviolet absorber and an ultraviolet scatterer.

[0176] The bonding layer 14 preferably uses a material having a dielectric loss tangent (tanδ) of 0.018 or less. The lower the value of the dielectric loss tangent, the more preferred. As the lower limit of the dielectric loss tangent, for example, 0.0001 or more can be cited. By using the bonding layer 14 having a dielectric loss tangent of 0.018 or less, the loss of electric energy of the radio wave in the radio wave reflector 11 is reduced, and the reflection intensity can be further enhanced.

[0177] In addition, the synthetic resin material of the adhesive layer 14 preferably has a relative dielectric constant that changes according to the frequency of the electric field. The relative dielectric constant refers to the ratio of the dielectric constant of the medium (synthetic resin material in this embodiment) to the dielectric constant of a vacuum. The relative dielectric constant changes according to the electric field, thereby increasing the intensity of the reflected wave in the electric field of a specific frequency. The relative dielectric constant preferably changes between 1.5 and 7, and more preferably changes between 1.8 and 6.5.

[0178] The bonding layer 14 preferably uses a bonding layer composed of a synthetic resin material having a dielectric loss tangent (tanδ) of 0.018 or less. The lower the dielectric loss tangent, the more preferred it is, usually 0.0001 or more. The dielectric loss tangent indicates the degree of electric energy loss in the dielectric, and the greater the dielectric loss tangent, the greater the electric energy loss. By using an bonding layer 14 having a dielectric loss tangent of 0.018 or less, the loss of electric energy of the radio wave in the radio wave reflector 11 is reduced, and the reflection intensity can be further enhanced.

[0179] (Protective layer 15)

[0180] The protective layer 15 covers at least one side of the conductive layer 16 to protect the conductive layer 16. The protective layer 15 of the present embodiment has a size corresponding to the substrate 13 in a top view. As the protective layer 15, for example, a sheet (film) made of a synthetic resin can be cited. As the synthetic resin, for example, one or more selected from PET (polyethylene terephthalate), COP (cycloolefin polymer), polyethylene, polypropylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyester, polyoxymethylene, polyamide, polyphenylene ether, vinylidene chloride, polyvinyl acetate, polyvinyl acetal, AS resin, ABS resin, acrylic resin, fluororesin, nylon resin, polyacetal resin, polycarbonate resin, polyamide resin, and polyurethane resin can be cited.

[0181] The thickness L5 of the protective layer 15 is preferably 20 μm or more, more preferably 38 μm or more, and further preferably 50 μm or more. On the other hand, the upper limit of the thickness L5 of the protective layer 15 is preferably 200 μm or less, and more preferably 150 μm or less.

[0182] When the pencil hardness test is performed on the protective layer 15 alone, the pencil hardness under the condition of 500 g of the surface load on the protective layer 15 is preferably "4B" or more, more preferably "B" or more, and further preferably "F" or more. If the pencil hardness test of the protective layer 15 alone is "4B" or more, the conductor 12 can be protected. In addition, if the pencil hardness test of the protective layer 15 alone is "F" or more, the conductor 12 can be more firmly protected.

[0183] The moisture permeability of the protective layer 15 at a temperature of 40°C and a humidity of 90% rh (relative humidity) is preferably 20 g / m 2 · 24h or less, more preferably 16g / m 2 24h or less, more preferably 12g / m 2 · 24h or less, more preferably 10g / m 2 · Less than 24h. When the protective layer 15 is at a temperature of 40°C and a humidity of 90% rh (relative humidity), the moisture permeability is 20g / m 2When the time is 24 hours or less, there are advantages that the conductive layer 16 is less likely to be corroded and the surface resistivity of the conductive layer 16 is less likely to increase. The "water vapor permeability" referred to in this specification is measured by a test method based on JIS Z 0208 (1976).

[0184] The protective layer 15 is preferably flexible. The longitudinal elastic modulus of the protective layer 15 is, for example, preferably 1 GPa or more, more preferably 1.2 GPa or more, and further preferably 1.5 GPa or more. On the other hand, the upper limit of the longitudinal elastic modulus of the protective layer 15 is, for example, preferably 4 GPa or less, more preferably 3.8 GPa or less, and further preferably 3.5 GPa or less.

[0185] The protective layer 15 may be subjected to anti-glare treatment or anti-reflection treatment. For example, when the protective layer 15 is composed of a film, the anti-glare treatment or anti-reflection treatment may be applied to at least one of the upper surface (front surface) and the lower surface (the surface facing the adhesive layer 14) of the film.

[0186] The anti-glare treatment is a treatment in which a concavo-convex shape is formed on at least one surface of the protective layer 15 to scatter light and suppress the reflection of the light source such as lighting on the protective layer 15. Examples of the method for implementing the anti-glare treatment include a method of applying a binder resin in which fine particles are dispersed on the surface of the film, sandblasting, chemical etching, and the like.

[0187] The anti-reflection treatment refers to the following treatment: an anti-reflection film is formed on at least one surface of the protective layer 15, and the reflected light reflected from the surface of the anti-reflection film and the reflected light reflected from the interface between the anti-reflection film and the film are attenuated by interference, thereby suppressing the reflection of the light source such as lighting. The anti-reflection film can be a single layer or a film with different refractive indices alternately stacked.

[0188] The protective layer 15 may be a layer in which a film subjected to an anti-glare treatment or an anti-reflection treatment is attached to one or both surfaces of a film made of a synthetic resin.

[0189] The protective layer 15 may contain an anti-ultraviolet agent, or the upper surface (surface) of the protective layer 15 may be subjected to an anti-ultraviolet treatment, or both the inclusion of an anti-ultraviolet agent and the anti-ultraviolet treatment may be performed. The anti-ultraviolet treatment refers to a process of forming a film containing an anti-ultraviolet agent by coating or the like. According to this structure, it is not easy for ultraviolet rays to invade the interior of the radio wave reflector 11, so even if the radio wave reflector 11 is used for a long time, the discoloration of the radio wave reflector 11 caused by ultraviolet rays can be suppressed. As described above, the anti-ultraviolet agent may be any one of an ultraviolet absorber and an ultraviolet scatterer. As the ultraviolet absorber, ethylhexyl methoxycinnamate, tert-butyl methoxydibenzoylmethane, dimethyl PABA octyl ester, etc., as the ultraviolet scatterer, titanium oxide, zinc oxide, etc., may be cited, but are not limited thereto.

[0190] (Configuration of the End of the Radio Wave Reflector 11)

[0191] The structure of the peripheral end of the radio wave reflector 11 is described in detail. All the conductors 12 constituting the conductive layer 16 are formed on the upper surface of the substrate 13. The conductors 12 are preferably arranged at least 5 mm inside the edge of the laminate 18. The edge of the laminate 18 refers to the edge 13a of the substrate 13 which is a part of the laminate 18. When the substrate 13, the protective layer 15, and the adhesive layer 14 are the same size, it can also be said to be the edge of each protective layer 15 and the adhesive layer 14. Figure 4 As shown, in the top view, the distance L11 between any position P1 of the edge of the laminate 18 (the edge 13a of the substrate 13) and the conductor 12 closest to the arbitrary position P1 is preferably set to be 5 mm or more. When viewed from above, the conductor 12 is covered by the substrate 13, the adhesive layer 14, the protective layer 15 and other retaining layers.

[0192] In addition, the conductor 12 is not arranged at the end of the laminate 18 including the edge, so the end of the laminate 18 including the edge is formed by laminating the adhesive layer 14 and the protective layer 15 on the upper surface of the substrate 13. Therefore, when viewed from the side, the conductor 12 is covered by these layers. Therefore, the conductor 12 of this embodiment is not exposed to the outside.

[0193] That is, the conductor 12 “is not exposed to the outside” means that the conductor 12 is covered by a holding layer such as the base material 13 , the adhesive layer 14 , and the protective layer 15 when viewed from the top or the side.

[0194] When the radio wave reflector 11 is composed of the laminate 18 and does not have the sealing material 17 described later as in the present embodiment, "not exposed to the outside" means that the conductor 12 is arranged at a position further inside than the end edge of the laminate 18 (the end edge 13a of the substrate 13) and is covered by retaining layers such as the substrate 13, the adhesive layer 14, and the protective layer 15 when viewed from above and from the side.

[0195] Normally, the radio wave reflector 11 deteriorates due to discoloration, corrosion, etc. caused by the conductor 12 being affected by the environment. According to the above configuration, since the conductor 12 is not exposed to the outside, the conductor 12 is not easily affected by the environment, and the radio wave reflector 11 can be prevented from deteriorating and has durability.

[0196] (Modification of the Configuration of the End of the Radio Wave Reflector 11)

[0197] Figure 7 (A) Figure 7(B) shows a modified example of the configuration of the end portion. The radio wave reflector 11 of this embodiment is provided with a sealing material 17 covering the side surface of the laminate 18 at least at a position corresponding to the conductor 12 constituting the conductive layer 16 around the laminate 18. The sealing material 17 only needs to cover the side surface of the laminate 18 in such a manner that at least the conductor 12 is not exposed to the outside when the radio wave reflector 11 is viewed from the side surface, such as Figure 7 As shown in (B), the side surfaces of the substrate 13, the conductive layer 16, the adhesive layer 14, and the protective layer 15 may be covered. The sealing material 17 has adhesiveness and adheres to the side surfaces of each layer.

[0198] In this embodiment, in the top view, the conductor 12 may be arranged on the substrate 13 and aligned with the end edge 13a of the substrate 13, or may be provided continuously along the end edge 13a of the substrate 13. That is, in the top view, the distance L11 between an arbitrary position P1 of the end edge of the laminate 18 (the end edge 13a of the substrate 13) and the conductor 12 closest to the arbitrary position P1 may also be 0.

[0199] When viewed from above, the conductor 12 is arranged at a position at least the distance of the sealant 17 inside the edge of the radio wave reflector 11, and the sealant 17 abuts against at least the side surface of the conductor 12 to prevent the conductor 12 from being exposed to the outside. The sealant 17 makes the conductor 12 less susceptible to environmental influences, and the radio wave reflector 11 can be prevented from deterioration and has durability.

[0200] It should be noted that the conductor 12 may also be formed at a position further inside than the edge 13a of the substrate 13. In this case, the conductor 12 is not only located further inside than the edge 13a of the substrate 13, but also is less susceptible to environmental influences due to the sealing material 17, and can be prevented from deterioration and have durability.

[0201] It should be noted that the conductor 12 may also be formed at a position further inside than the edge 13a of the substrate 13. In this case, the conductor 12 is not only located further inside than the edge 13a of the substrate 13, but also is less susceptible to environmental influences due to the sealing material 17, and can be prevented from deterioration and have durability.

[0202] That is, in Figure 7 In the present embodiment shown, the conductor 12 “is not exposed to the outside” means that the conductor 12 is covered by the sealant 17 when the radio wave reflector 11 is viewed from the side, and is covered by the base material 13, the adhesive layer 14, and the protective layer 15 when viewed from the top.

[0203] The length L12 of the sealing material 17 protruding from the laminate 18 (the width of the sealing material 17) is constant when viewed from above, preferably 0.01 mm to 10 mm. The length L10 of one side of the radio wave reflector 11 is the length L13 of one side of the laminate 18 plus twice the protruding length L12 of the sealing material 17.

[0204] A synthetic resin is used as the sealing material 17 , and examples of the synthetic resin include silicone resin, epoxy resin, polyester resin, acrylic resin, polyurethane resin, polyimide resin, polyvinyl chloride resin, and nylon resin.

[0205] Other components and functions Figure 2 to Figure 4 The embodiments shown are the same, and therefore the same reference numerals are given to corresponding structures, and detailed descriptions thereof are omitted.

[0206] (Method for Manufacturing Radio Wave Reflector 11 of Embodiment Where Sealing Material 17 Is Provided)

[0207] Figure 7 The radio wave reflector 11 of the embodiment shown can also be installed on a setting location such as a wall after being manufactured as the radio wave reflector 11. The manufacturing method of the radio wave reflector 11 is as follows. First, a step of forming the laminate 18 is performed. In this step, a conductive layer 16 is formed on the upper surface of the substrate 13, and the protective layer 15 is adhered to the conductive layer 16 via the adhesive layer 14 to form the laminate 18. Next, a step of setting the sealing material 17 is performed. In this step, the sealing material 17 for preventing the conductor 12 from being exposed is set at least at a position corresponding to the conductive layer 16 around the laminate 18. The sealing material 17 has adhesiveness and is therefore installed on the side of the laminate 18. Through these steps, the radio wave reflector 11 is manufactured. Figure 7 The radio wave reflector 11 of the embodiment shown.

[0208] In addition, the process of setting the sealing material 17 may be performed first, and then the process of forming the laminate 18 may be performed. In the process of setting the sealing material 17, the sealing material 17 is arranged in a ring shape on the surface of the release paper, etc. The space surrounded by the sealing material 17 has the same shape and size as the laminate 18 when viewed from above. Next, the process of forming the laminate 18 is performed as described above. Then, the process of embedding the laminate 18 in the space surrounded by the sealing material 17 is performed. Thus, the radio wave reflector 11 is manufactured. The sealing material 17 of the radio wave reflector 11 manufactured in this way is located at a position corresponding to at least the conductive layer 16 around the laminate 18.

[0209] (Construction Method of Radio Wave Reflector 11 in Embodiment Where Sealing Material 17 Is Provided)

[0210] Figure 7The radio wave reflector 11 of the embodiment shown can also be installed in the following construction method at the installation position of the installation surface such as a wall. The installation position is, for example, a wall, partition, column, eaves, outer wall of a building, window, etc., which can be a flat surface or a curved surface. First, a process of installing the laminate 18 at the installation position is performed. In this process, the laminate 18 is installed at the installation position in a manner such that the substrate 13 contacts the installation position using installation means such as double-sided tape and adhesive. Next, a process of installing the sealing material 17 is performed. In this process, a sealing material 17 is provided at a position around the laminate 18 corresponding to at least the conductive layer 16 so as not to expose the conductor 12.

[0211] Alternatively, the process of installing the sealing material 17 may be performed first, and then the process of installing the laminate 18 at the installation location may be performed. First, the sealing material 17 is provided in a ring shape around the installation location of the laminate 18 on the installation surface such as a wall. Then, the laminate 18 is installed at the installation location in a manner of being embedded in the space surrounded by the sealing material 17. Thus, the radio wave reflector 11 is constructed at the installation location.

[0212] exist Figure 7 In the illustrated embodiment, the radio wave reflector 11 includes one laminate 18, but the radio wave reflector 11 may also include a plurality of laminates 18 disposed at intervals. Figure 8 In the example, four laminates 18 are arranged. In the top view, a sealing material 17 is arranged on the side where there is no adjacent laminate 18 among the four sides of each laminate 18, and the sealing material 17 is filled in the entire space in the space between the adjacent laminates 18. Thus, the sealing material 17 is arranged around each laminate 18. The construction method of such a radio wave reflector 11 is as follows. First, a process of installing a plurality of laminates 18 at intervals on a setting location such as a wall using a double-sided tape, an adhesive or the like is performed. Next, a process of installing the sealing material 17 is performed. In this process, the sealing material 17 is arranged at least at a position corresponding to the conductive layer of the side where there is no adjacent laminate 18 among the four sides of the laminate 18. And the sealing material 17 is arranged in the entire space between the adjacent laminates 18. Thus, the radio wave reflector 11 is constructed at the setting location. In addition, the process of installing the sealing material 17 can be performed first, and then the process of installing the laminate 18 at the setting location is performed. First, the sealing material 17 is provided in a ring shape around the location where the plurality of laminated bodies 18 are to be provided. Furthermore, when the plurality of laminated bodies 18 are installed at intervals at the location, the sealing material is provided in the space between adjacent laminated bodies 18. Next, the laminated bodies 18 are installed at the location in a manner such that they are embedded in the space surrounded by the sealing material 17.

[0213] (How to use)

[0214] The radio wave reflector 11 of the embodiment can also be used by sticking it to the walls, partitions, columns, door eaves, outer walls, windows and other surfaces of the building where it is installed by means of adhesives or the like. In addition, it can also be used as interior paper or decorative material, for example. The inner layer of paper is a paper material installed on the inner surface of the interior material. Examples of interior materials include inner walls, ceilings, partitions, floor materials, etc. Examples of decorative materials include posters, decorative stickers, and colored glass films. Examples of decorative materials include wall materials, floor materials, doors, lighting covers, lattices, columns, televisions, table tops, etc. In Figure 6 , an example is shown in which a poster as a decorative material 30A is attached to a wall surface, and a decorative material 30B is attached to a lighting cover.

[0215] By installing the decorative materials 30A and 30B including the radio wave reflector 11 on indoor equipment and building materials, radio waves entering the room from outside through the window 33 are reflected by the decorative materials 30A and 30B. Thus, radio waves reach a wider range of the indoor space S, and the convenience of radio wave reception is improved.

[0216] In addition, the radio wave reflector 11 is not limited to the example used as wallpaper, and can also be used for printing paper of printed plywood. In this case, the plywood containing the radio wave reflector 11 can also be used to form doors, wall surfaces, partitions, outer wall materials, roofs, ceilings, floor materials, skirting boards, etc.

[0217] Furthermore, the radio wave reflector 11 is not limited to a flat plate, but may also be a spherical surface. Figure 6 (B) is a view of the room viewed from above. The building material 30 having the radio wave reflector 11 on the surface is a spherical corner post 30C at the corner of the room. The radio waves entering from the window 33 are reflected by the corner post 30C, and the radio waves are diffused to a wider range in the indoor space S. It should be noted that Figure 6 (A) Figure 6 (B) is only a schematic diagram showing the outgoing wave and does not represent the actual range of the reflected radio wave.

[0218] <Evaluation Test A>

[0219] For the radio wave reflector 11, Examples 1 to 13 and Comparative Examples 1 to 8 were prepared, and evaluation tests were conducted on pencil hardness test, adhesion of the protective layer to the adherend layer, radio wave reflectivity, total light transmittance, haze, surface resistivity, blistering, whitening, yellowing degree Δb*, etc. However, the radio wave reflector 11 of the present invention is not limited to Examples 1 to 13.

[0220] (Description of Examples and Comparative Examples)

[0221] In Examples 1 to 13 and Comparative Examples 1 to 8, the test pieces were prepared as follows. 1 part of a crosslinking agent was added to 100 parts of the following adhesive and stirred for 3 minutes to obtain an adhesive composition. Next, a protective layer was laid on a coating table, the adhesive composition was dripped, and a coating machine adjusted to a thickness of 25 μm was moved to obtain an adhesive layer. The test piece was dried at a temperature of 110° C. for 5 minutes and then heated and aged at 40° C. for 48 hours to obtain a protective layer and an adhesive layer of the test piece.

[0222] Next, the conductive layer, the protective layer and the adhesive layer prepared previously were vacuum laminated at 40° C. for 6 minutes to obtain a test piece. In the following conditions, for a test piece without an adhesive layer and a protective layer, the step of obtaining the protective layer and the adhesive layer was not performed.

[0223] (1) Embodiment 1

[0224] As Example 1, the conditions for the test piece are as follows.

[0225] Conductive layer

[0226] Shape: Square with a side length of 20cm

[0227] Material: PET sheet

[0228] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0229] (The grid pattern is a grid pattern in which the area 12a without a conductor surrounded by the conductor 12 is in the shape of a square.) Figure 3 (B) The pattern of the conductors 12 shown in FIG. 1 ). The grid pitch refers to the interval L8 between adjacent parallel conductors 12 in the grid pattern.

[0230] Adhesive layer

[0231] Adhesive: X313-295S-14 (manufactured by SAIDEN Chemical)

[0232] Acid value: 0.8mgKOH / g

[0233] Hydroxyl value: 115mgKOH / g

[0234] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0235] Protective layer

[0236] Material: PET sheet

[0237] Thickness: 125μm

[0238] Pencil hardness test (protective layer only): F

[0239] Moisture permeability: 4.8g / m 2 ·24h

[0240] (2) Embodiment 2

[0241] As Example 2, the conditions for the test piece are as follows.

[0242] Conductive layer

[0243] Shape: Square with a side length of 20cm

[0244] Material: PET sheet

[0245] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0246] Adhesive layer

[0247] Adhesive: 2980 (manufactured by Soken Chemical)

[0248] Acid value: 0.5mgKOH / g

[0249] Hydroxyl value: 95mgKOH / g

[0250] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0251] Protective layer

[0252] Material: PET sheet

[0253] Thickness: 125μm

[0254] Pencil hardness test (protective layer only): F

[0255] Moisture permeability: 4.8g / m 2 ·24h

[0256] (3) Embodiment 3

[0257] As Example 3, the conditions for the test piece are as follows.

[0258] Conductive layer

[0259] Shape: Square with a side length of 20cm

[0260] Material: PET sheet

[0261] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0262] Adhesive layer

[0263] Adhesive: 2006HE (manufactured by Soken Chemical)

[0264] Acid value: 30mgKOH / g

[0265] Hydroxyl value: 10mgKOH / g

[0266] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0267] Protective layer

[0268] Material: PET sheet

[0269] Thickness: 125μm

[0270] Pencil hardness test (protective layer only): F

[0271] Moisture permeability: 4.8g / m 2 ·24h

[0272] (4) Embodiment 4

[0273] As Example 4, the conditions for the test piece are as follows.

[0274] Conductive layer

[0275] Shape: Square with a side length of 20cm

[0276] Material: PET sheet

[0277] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0278] Adhesive layer

[0279] Adhesive: 2137KH (manufactured by Soken Chemical)

[0280] Acid value: 10mgKOH / g

[0281] Hydroxyl value: 8.0mgKOH / g

[0282] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0283] Protective layer

[0284] Material: PET sheet

[0285] Thickness: 125μm

[0286] Pencil hardness test (protective layer only): F

[0287] Moisture permeability: 4.8g / m 2 ·24h

[0288] (5) Embodiment 5

[0289] As Example 5, the conditions of the test piece are as follows.

[0290] Conductive layer

[0291] Shape: Square with a side length of 20cm

[0292] Material: PET sheet

[0293] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0294] Adhesive layer

[0295] Adhesive: 2980 (manufactured by Soken Chemical)

[0296] Acid value: 0.5mgKOH / g

[0297] Hydroxyl value: 95mgKOH / g

[0298] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0299] Protective layer

[0300] Material: PET sheet

[0301] Thickness: 75μm

[0302] Pencil hardness test (protective layer only): F

[0303] Moisture permeability: 8.0g / m 2 ·24h

[0304] (6) Embodiment 6

[0305] As Example 6, the conditions for the test piece are as follows.

[0306] Conductive layer

[0307] Shape: Square with a side length of 20cm

[0308] Material: PET sheet

[0309] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0310] Adhesive layer

[0311] Adhesive: 2980 (manufactured by Soken Chemical)

[0312] Acid value: 0.5mgKOH / g

[0313] Hydroxyl value: 95mgKOH / g

[0314] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0315] Protective layer

[0316] Material: PET sheet

[0317] Thickness: 50μm

[0318] Pencil hardness test (protective layer only): F

[0319] Moisture permeability: 12g / m 2 ·24h

[0320] (7) Embodiment 7

[0321] As Example 7, the conditions for the test piece are as follows.

[0322] Conductive layer

[0323] Shape: Square with a side length of 20cm

[0324] Material: PET sheet

[0325] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 45μm

[0326] Adhesive layer

[0327] Adhesive: 2980 (manufactured by Soken Chemical)

[0328] Acid value: 0.5mgKOH / g

[0329] Hydroxyl value: 95mgKOH / g

[0330] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0331] Protective layer

[0332] Material: PET sheet

[0333] Thickness: 125μm

[0334] Pencil hardness test (protective layer only): F

[0335] Moisture permeability: 4.8g / m 2 ·24h

[0336] (8) Embodiment 8

[0337] As Example 8, the conditions for the test piece are as follows.

[0338] Conductive layer

[0339] Shape: Square with a side length of 20cm

[0340] Material: PET sheet

[0341] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0342] Adhesive layer

[0343] Adhesive: 1604N (manufactured by Soken Chemical)

[0344] Acid value: 45mgKOH / g

[0345] Hydroxyl value: 6.6mgKOH / g

[0346] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0347] Protective layer

[0348] Material: PET sheet

[0349] Thickness: 125μm

[0350] Pencil hardness test (protective layer only): F

[0351] Moisture permeability: 4.8g / m 2 ·24h

[0352] (9) Embodiment 9

[0353] As Example 9, the conditions of the test piece are as follows.

[0354] Conductive layer

[0355] Shape: Square with a side length of 20cm

[0356] Material: PET sheet

[0357] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0358] Adhesive layer

[0359] Adhesive: 1502C (manufactured by Soken Chemical)

[0360] Acid value: 0.1mgKOH / g

[0361] Hydroxyl value: 8.8mgKOH / g

[0362] Crosslinking agent: E-AX (Soken Chemical) epoxy type

[0363] Protective layer

[0364] Material: PET sheet

[0365] Thickness: 125μm

[0366] Pencil hardness test (protective layer only): F

[0367] Moisture permeability: 4.8g / m 2 ·24h

[0368] (10) Embodiment 10

[0369] As Example 10, the conditions of the test piece are as follows.

[0370] Conductive layer

[0371] Shape: Square with a side length of 20cm

[0372] Material: PET sheet

[0373] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0374] Adhesive layer

[0375] Adhesive: 2147 (manufactured by Soken Chemical)

[0376] Acid value: 4.0mgKOH / g

[0377] Hydroxyl value: 32mgKOH / g

[0378] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0379] Protective layer

[0380] Material: PET sheet

[0381] Thickness: 125μm

[0382] Pencil hardness test (protective layer only): F

[0383] Moisture permeability: 4.8g / m 2 ·24h

[0384] (11) Embodiment 11

[0385] As Example 11, the conditions for the test piece are as follows.

[0386] Conductive layer

[0387] Shape: Square with a side length of 20cm

[0388] Material: PET sheet

[0389] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0390] Adhesive layer

[0391] Adhesive: 2980 (manufactured by Soken Chemical)

[0392] Acid value: 0.5mgKOH / g

[0393] Hydroxyl value: 95mgKOH / g

[0394] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0395] Protective layer

[0396] Material: PET sheet (KB125N05 manufactured by KIMOTO)

[0397] Thickness: 125μm

[0398] Pencil hardness test (protective layer only): 3H

[0399] Moisture permeability: 4.8g / m 2 ·24h

[0400] (12) Embodiment 12

[0401] As Example 12, the conditions for the test piece are as follows.

[0402] Conductive layer

[0403] Shape: Square with a side length of 20cm

[0404] Material: PET sheet

[0405] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0406] Adhesive layer

[0407] Adhesive: 2980 (manufactured by Soken Chemical)

[0408] Acid value: 0.5mgKOH / g

[0409] Hydroxyl value: 95mgKOH / g

[0410] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0411] Protective layer

[0412] Material: PET sheet

[0413] Thickness: 38μm

[0414] Pencil hardness test (protective layer only): F

[0415] Moisture permeability: 16g / m 2 ·24h

[0416] (13) Embodiment 13

[0417] As Example 13, the conditions for the test piece are as follows.

[0418] Conductive layer

[0419] Shape: Square with a side length of 20cm

[0420] Material: PET sheet

[0421] Conductor: Grid-shaped circular pattern made of copper (Cu) with a line width of 2.3 μm, a line thickness of 1.6 μm, and a grid spacing of 100 μm

[0422] (The grid-shaped / circular pattern refers to a pattern in which the shape of the area 12a without a conductor surrounded by the conductor 12 includes a square pattern and a circular pattern, and refers to the modification example 4 described later ( Fig.12 ) shown in the pattern. The lattice spacing refers to the spacing between adjacent parallel conductors 12 (in Fig.12 The first surrounding portion 41 is disposed at a distance L8 between the conductors 12 (in Fig.12 The diameter of the second surrounding portion 51) is equal to the grid spacing.

[0423] Adhesive layer

[0424] Adhesive: 2980 (manufactured by Soken Chemical)

[0425] Acid value: 0.5mgKOH / g

[0426] Hydroxyl value: 95mgKOH / g

[0427] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0428] Protective layer

[0429] Material: PET film (TOYOBO ESTER Film HB3UO)

[0430] Thickness: 50μm

[0431] Pencil hardness test (protective layer only): 3H

[0432] Moisture permeability: 4.8g / m 2 ·24h

[0433] (14) Comparative Example 1

[0434] As Comparative Example 1, the conditions for the test piece are as follows.

[0435] Conductive layer

[0436] Shape: Square with a side length of 20cm

[0437] Material: PET sheet

[0438] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0439] Adhesive layer, protective layer

[0440] none

[0441] (15) Comparative Example 2

[0442] As Comparative Example 2, the conditions for the test piece are as follows.

[0443] Conductive layer

[0444] Shape: Square with a side length of 20cm

[0445] Material: PET sheet

[0446] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 45μm

[0447] Adhesive layer, protective layer

[0448] none

[0449] (16) Comparative Example 3

[0450] As Comparative Example 3, the conditions for the test piece are as follows.

[0451] Conductive layer

[0452] Shape: Square with a side length of 20cm

[0453] Material: PET sheet

[0454] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0455] Adhesive layer

[0456] Adhesive: 2980 (manufactured by Soken Chemical)

[0457] Acid value: 0.5mgKOH / g

[0458] Hydroxyl value: 95mgKOH / g

[0459] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0460] Protective layer

[0461] Material: PET sheet

[0462] Thickness: 38μm

[0463] Pencil hardness test (protective layer only): F

[0464] Moisture permeability: 16g / m 2 ·24h

[0465] (17) Comparative Example 4

[0466] As Comparative Example 4, the conditions for the test piece are as follows.

[0467] Conductive layer

[0468] Shape: Square with a side length of 20cm

[0469] Material: PET sheet

[0470] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0471] Adhesive layer

[0472] Adhesive: 2980 (manufactured by Soken Chemical)

[0473] Acid value: 0.5mgKOH / g

[0474] Hydroxyl value: 95mgKOH / g

[0475] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0476] Protective layer

[0477] Material: PET sheet

[0478] Thickness: 38μm

[0479] Pencil hardness test (protective layer only): F

[0480] Moisture permeability: 16g / m 2 ·24h

[0481] (18) Comparative Example 5

[0482] As Comparative Example 5, the conditions for the test piece are as follows.

[0483] Conductive layer

[0484] Shape: Square with a side length of 20cm

[0485] Material: PET sheet

[0486] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0487] Adhesive layer

[0488] Adhesive: 2980 (manufactured by Soken Chemical)

[0489] Acid value: 0.5mgKOH / g

[0490] Hydroxyl value: 95mgKOH / g

[0491] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0492] Protective layer

[0493] Material: PET sheet

[0494] Thickness: 25μm

[0495] Pencil hardness test (protective layer only): F

[0496] Moisture permeability: 24g / m 2 ·24h

[0497] (19) Comparative Example 6

[0498] As Comparative Example 6, the conditions for the test piece are as follows.

[0499] Conductive layer

[0500] Shape: Square with a side length of 20cm

[0501] Material: PET sheet

[0502] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0503] Adhesive layer

[0504] Adhesive: 2980 (manufactured by Soken Chemical)

[0505] Acid value: 0.5mgKOH / g

[0506] Hydroxyl value: 95mgKOH / g

[0507] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0508] Protective layer

[0509] Material: PET sheet

[0510] Thickness: 25μm

[0511] Pencil hardness test (protective layer only): F

[0512] Moisture permeability: 24g / m 2 ·24h

[0513] (20) Comparative Example 7

[0514] As Comparative Example 7, the conditions for the test piece are as follows.

[0515] Conductive layer

[0516] Shape: Square with a side length of 20cm

[0517] Material: PET sheet

[0518] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0519] Adhesive layer

[0520] Adhesive: 2980 (manufactured by Soken Chemical)

[0521] Acid value: 0.5mgKOH / g

[0522] Hydroxyl value: 95mgKOH / g

[0523] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0524] Protective layer

[0525] Material: PP sheet

[0526] Thickness: 50μm

[0527] Pencil hardness test (protective layer only): B

[0528] Moisture permeability: 4.5g / m 2 ·24h

[0529] (21) Comparative Example 8

[0530] As Comparative Example 8, the conditions for the test piece are as follows.

[0531] Conductive layer

[0532] Shape: Square with a side length of 20cm

[0533] Material: PET sheet

[0534] Conductor: Grid pattern made of silver (Ag), line width 0.8μm, line thickness 0.5μm, grid spacing 30μm

[0535] Adhesive layer

[0536] Adhesive: 2980 (manufactured by Soken Chemical)

[0537] Acid value: 0.5mgKOH / g

[0538] Hydroxyl value: 95mgKOH / g

[0539] Crosslinking agent: L-45K (Soken Chemical) isocyanate

[0540] Protective layer

[0541] Material: LDPE sheet

[0542] Thickness: 50μm

[0543] Pencil hardness test (protective layer only): 4B

[0544] Moisture permeability: 10g / m 2 ·24h

[0545] (Measurement method)

[0546] (1) Determination of moisture permeability of protective layer

[0547] A protective layer was placed in the measuring device, and the device was left in an atmosphere of temperature 40° C. and humidity 90% rh for 48 hours. After water vapor was supplied from one side, the amount of water that passed through was measured to obtain the moisture permeability.

[0548] (2) Adhesion strength measurement

[0549] The adhesive layer and the protective layer were attached to a PET film of 188 μm in thickness cut into 25 mm squares, and the PET film was pulled in a 180-degree direction at a speed of 300 mm / min using an AUTOGRAPH to obtain the results.

[0550] (3) Evaluation of radio wave reflectivity

[0551] For incident waves of 4.7 GHz and 28 GHz, the receiving intensity was measured while changing the incident angle and the reflection angle, and evaluated by comparing with the receiving intensity of the aluminum plate. Regarding the evaluation of the receiving intensity, when it was evaluated to be equal to that of the aluminum plate, it was evaluated as "◎", when the difference in receiving intensity with the aluminum plate was greater than -10 dB and less than -20 dB, it was evaluated as "○", and when the difference in receiving intensity with the aluminum plate was greater than -20 dB, it was evaluated as "×".

[0552] (4) Total light transmittance and haze measurement

[0553] The test piece was cut into 5 cm squares, and the total light transmittance and haze were measured using a haze meter HM-150 (manufactured by Murakami Color Research Laboratory Co., Ltd.) by a measurement method in accordance with JIS-K7136:2000 to obtain the results.

[0554] (5) Determination of surface resistivity

[0555] Each test piece was subjected to the heat and humidity resistance test (7) described later, and then measured using EC-80P manufactured by NAPSON Corporation to obtain the result.

[0556] (6) Pencil hardness test method

[0557] According to JIS K 5600-5-4, a load within 500±10 g was applied to check the hardness of the mesh pattern of the conductor when it was deformed, and the hardness that was one level lower was taken as the hardness.

[0558] (7) Heat and humidity resistance test method

[0559] The test piece was placed in a constant temperature and humidity chamber adjusted to a temperature of 60°C and a humidity of 95% rh and left to stand for 500 hours. After the test piece was taken out and left at room temperature for 4 hours, the presence or absence of blistering and whitening was visually confirmed. Then, the (2) adhesion measurement, (3) evaluation of radio wave reflectivity, (4) transmittance measurement, and haze measurement were performed again, and the results were compared before (initial) and after the heat and humidity resistance test. Regarding the adhesion, the ratio of the adhesion after the heat and humidity resistance test to the adhesion before (initial) the heat and humidity resistance test was calculated (initial ratio).

[0560] (8) Light resistance test

[0561] The test piece was placed in Xenon Sunshine Weather Ometer Ci4000 manufactured by ATLAS, and the irradiance in the tank was set to 60 W / m 2 (300-400nm), black standard temperature (BST) 65±3℃, humidity 50±5%RH, tank temperature 38℃. Measure the yellowing degree Δb* before and after 1300 hours of irradiation (1 year of direct sunlight). Then, perform the evaluation of (3) radio wave reflectivity, (4) transmittance measurement, and haze measurement again, and compare before (initial) and after the light resistance test.

[0562] (Test results)

[0563] Tables 1-1 and 1-2 show the test results of Examples, and Table 2 shows the test results of Comparative Examples.

[0564] [Table 1-1]

[0565]

[0566] [Table 1-2]

[0567]

[0568] [Table 2]

[0569]

[0570] As can be seen from Table 1-1, Table 1-2, and Table 2, in Examples 1 to 13, the pencil effect test on the test piece was "4H", whereas in Comparative Examples 1 to 8, it was "6B", "B", "2B", and "5B". At this time, the evaluation of the radio wave reflectivity of Examples 1 to 13 was "◎", whereas the evaluation of the radio wave reflectivity of Comparative Examples 1 to 8 was "×".

[0571] According to the results, the evaluation of radio wave reflectivity is determined by the hardness of the protective layer, so it is known that in order to maintain good radio wave reflectivity, it is also necessary to select an appropriate hardness of the protective layer. In addition, for Comparative Examples 1 and 2, the surface resistivity shows a high value, and the radio wave reflectivity is "×", so when the surface resistivity shows a high value, it is known that the protective layer is peeled, deformed, or damaged, and in this case, it is also known that the radio wave reflectivity is deteriorated.

[0572] In short, it can be seen that in Examples 1 to 13, the pencil hardness test was "F" or higher, so that the conductor can be protected and practical radio wave reflectivity can be obtained without impairing the radio wave reflectivity.

[0573] In addition, in Examples 1 to 13, the evaluation of radio wave reflectivity after the heat and humidity resistance test and after the light resistance test was "◎," confirming that the radio wave reflectivity was not impaired. In addition, after these tests, the haze was less than 30%, and the total light transmittance was 70% or more, confirming that transparency was maintained. In addition, in Examples 1 to 13, the yellowing degree after the light resistance test was 15 or less, confirming that the discoloration did not progress significantly and degradation was not likely to occur.

[0574] <Evaluation Test B>

[0575] Examples 21 to 26 and Comparative Example 21 were prepared as radio wave reflectors 11, and the difference in yellow index, the rate of change r of surface resistivity during the heat and humidity resistance test, and the difference in reflection intensity were evaluated between Examples 21 to 26 and Comparative Example 1. However, the radio wave reflector 11 of the present invention is not limited to Examples 21 to 26.

[0576] (Description of Examples and Comparative Examples)

[0577] (Example 21)

[0578] The radio wave reflector 11 prepared as Example 21 has Figure 2 to Figure 4 The radio wave reflector 11 has the same structure as the embodiment shown. The planar shape of the radio wave reflector 11 is a square, the length L10 of one side is set to 20 cm, and the thickness L1 of the radio wave reflector 11 is set to 250 μm.

[0579] The radio wave reflector 11 has a reflection intensity of radio waves of more than -30 dB in a frequency band of more than 3 GHz and less than 300 GHz. In addition, the maximum value of the reflection intensity of radio waves when the radio wave reflector 11 reflects incident waves of frequencies of more than 3 GHz and less than 300 GHz (hereinafter also referred to as "the maximum value of the radio wave reflection intensity") is -20 dB.

[0580] As the substrate 13, a synthetic resin material sheet made of PET (manufactured by Toray Industries, Ltd., LUMIR ROR 50T60) was used, and the thickness L2 of the substrate 13 was set to 50 μm.

[0581] The conductor 12 of the conductive layer 16 is a linear metal thin film made of silver (Ag), and the thickness (film thickness) L3 is set to 500nm, the line width L6 is set to 0.5μm, and the length L7 between adjacent conductors 12 is set to 60μm. The surface resistivity of the conductive layer 16 is 1.7Ω / □, and the conductor coverage is 3.3%. The distance L11 between the end edge 13a of the substrate 13 of the laminate 18 (that is, the end edge of the protective layer 15) and the conductor 12 is set to 10mm.

[0582] As the adhesive layer 14, a rubber adhesive is used. In detail, the adhesive layer 14 is a mixture of a rubber polymer (a mixture of 50% by mass of styrene-(ethylene-propylene)-styrene block copolymer and 50% by mass of styrene-(ethylene-propylene) block copolymer, 15% styrene content, and a weight-average molecular weight of 130,000) 100 parts by weight, a synthetic resin (Mitsui Chemicals, FMR-0150) 40 parts by weight, a softener (JX Nippon Mining and Petrochemicals, LV-100) 20 parts by weight, an antioxidant (ADEKA, ADK STAB AO-330) 0.5 parts by weight and toluene 150 parts by weight are added into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, a dropping funnel and a stirring device, and stirred at 40°C for 5 hours. The thickness L4 of the adhesive layer 14 is set to 150 μm. The dielectric loss tangent of the adhesive layer 14 is 0.04.

[0583] A synthetic resin sheet made of PET (manufactured by Toray Industries, Inc., LUMI RROR50T60) was used as the protective layer 15. The thickness L5 of the protective layer 15 was set to 50 μm.

[0584] In Example 21, the sealing material 17 is not provided. It should be noted that the thickness L1 of the radio wave reflector 11, the thickness L3 of the conductor 12, the thickness L2 of the base material 13, the thickness L4 of the adhesive layer 14, and the thickness L5 of the protective layer 15 are obtained by measuring arbitrary multiple locations and calculating the average value of the measured values. In the measurement of the thicknesses L1 to L5, for example, a reflectivity spectroscopic film thickness measuring instrument (for example, F3-CS-NIR manufactured by FILMETRICS Co., Ltd.) is used as a measuring instrument.

[0585] The manufacturing method of the radio wave reflector 11 of Example 21 is described. First, the conductor 12 is formed on the substrate 13. On one surface of a copper foil with a thickness of 5μm to 200μm having sufficient strength as a metal layer, a core layer of 0.01μm to 3μm is formed by electrolysis or chemical plating. Then, the conductor 12 of a given configuration pattern is formed on the surface of the core layer by electrolysis or chemical plating. Next, the entire conductor 12 is covered with the substrate 13. An adhesive is pre-coated on the substrate 13. Then, the copper foil and the core layer are etched away. Thus, the conductor 12 is formed on the substrate 13.

[0586] Then, the protective layer 15 is attached to the side opposite to the base 13 via the conductor 12 via the adhesive layer 14. The protective layer 15 is attached to the conductor 12 of the base 13 using the adhesive layer 14 so that no air bubbles are introduced. Thus, the radio wave reflector 11 is manufactured.

[0587] (Example 22)

[0588] The radio wave reflector 11 prepared in Example 22 differs from that in Example 21 in that the distance L11 between the edge of the substrate 13 of the laminate 18 and the conductor 12 is set to 5 mm. The other configurations are the same as those in Example 21.

[0589] (Example 23)

[0590] The radio wave reflector 11 prepared in Example 23 is different from that in Examples 21 and 22. Figure 7 The radio wave reflector 11 has the same structure as the embodiment shown. A sealing material 17 is provided around the laminate 18, and the length L12 of the sealing material 17 protruding from the laminate 18 (the width of the sealing material 17) is 5 mm. As the sealing material 17, SEKISUI SILICONE SEALANT CLEAR (Sekisui Silicone Clean) (model SSBCL-333) of SEKISUI FULLER Co., Ltd., which is a polysiloxane resin, is used. The distance L11 between the edge of the laminate 18 and the conductor 12 is 0, and the conductor 12 is located at the edge of the substrate 13 of the laminate 18. The length L10 of one side of the radio wave reflector 11 is 20.1 cm. The other structures are the same as those of Example 21.

[0591] (Example 24)

[0592] The radio wave reflector 11 prepared as Example 24 has the same Figure 7The radio wave reflector 11 has the same structure as the embodiment shown. The difference from Example 23 is that an acrylic resin is used as the sealing material 17. The acrylic resin is PMMA (polymethyl methacrylate). The other structures are the same as those of Example 23.

[0593] (Example 25)

[0594] The radio wave reflector 11 prepared as Example 25 is similar to that of Example 23 and has Figure 7 The radio wave reflector 11 of the same structure as the embodiment shown in the figure. The difference from Example 23 is that the sealing material 17 uses an epoxy resin. The epoxy resin contains jER828 (epoxy equivalent 190) of Mitsubishi Chemical Corporation as an epoxy main agent and jER CURE YN100 (amine value 350KOHmg / g, amine equivalent 80.1) of Mitsubishi Chemical Corporation as a curing agent. The curing time is 3 days and the curing temperature is 40 degrees. The other structures are the same as those of Example 23.

[0595] (Example 26)

[0596] The radio wave reflector 11 prepared in Example 26 differs from that in Example 21 in that the distance L11 between the edge 13a of the substrate 13 of the laminate 18 and the conductor 12 is set to 1 mm. The other configurations are the same as those in Example 21.

[0597] (Comparative Example 21)

[0598] The radio wave reflector 11 prepared as Comparative Example 21 is different from Example 21 in the following respects. The distance L11 between the edge of the substrate 13 of the laminate 18 and the conductor 12 is 0, that is, the conductor 12 is located along the edge of the substrate 13 of the laminate 18. The other structures are the same as those of Example 21.

[0599] (Measurement method and calculation method)

[0600] (Determination of yellowness index and calculation of difference in yellowness index)

[0601] The difference in yellow index is calculated by the following method. First, the yellow index (YI0) of Examples 21 to 26 and Comparative Example 1 (hereinafter also referred to as "samples") as the measurement objects is measured. Next, the samples are subjected to a heat and humidity resistance test, and the yellow index (YI) of the samples after the heat and humidity resistance test is measured. Then, the difference in yellow index is calculated by subtracting the yellow index (YI0) before the heat and humidity resistance test from the yellow index (YI) after the heat and humidity resistance test. That is, the difference in yellow index = YI-YI0. The determination of the yellow index is carried out according to the method of JIS K7373. As a heat and humidity resistance test, the following test is carried out: After the radio wave reflector 11 is placed in a constant temperature and humidity chamber adjusted to a temperature of 60°C and a humidity of 95% RH (relative humidity of 95%) for 500 hours, the radio wave reflector 11 is taken out of the constant temperature and humidity chamber and left to stand at room temperature for 4 hours.

[0602] (Measurement of surface resistivity)

[0603] Regarding the surface resistivity, for the sample before the heat and humidity resistance test, the conductive layer 16 was formed and exposed during sample manufacturing, and the measurement terminals were brought into contact with the surface of the conductive layer 16, and the surface resistivity was measured by the four-terminal method in accordance with JIS K6911. In addition, for the sample after the heat and humidity resistance test, since the conductive layer 16 was not exposed, the surface resistivity was measured by the eddy current method using a non-contact resistance measuring instrument (manufactured by NAPSON Co., Ltd., trade name: EC-80P or its equivalent).

[0604] (Calculation of the rate of change of surface resistivity during heat and humidity resistance test)

[0605] The rate of change r of the surface resistivity during the heat and humidity test is calculated by the following method. First, the surface resistivity of the sample before the heat and humidity test is measured. Next, the heat and humidity test is performed on the sample, and the surface resistivity of the sample after the heat and humidity test is measured. Then, according to the formula of the rate of change r of the surface resistivity during the heat and humidity test = (surface resistivity r1 before the heat and humidity test - surface resistivity r2 after the heat and humidity test) / surface resistivity r1 before the heat and humidity test × 100, the rate of change of the surface resistivity during the heat and humidity test is calculated. The surface resistivity of the conductor 12 of the conductive layer 16 is taken as the surface resistivity of the radio wave reflector 11.

[0606] The case where the rate of change of surface resistivity is less than 10% is evaluated as "◎", the case where the rate of change of surface resistivity is 10% or more and less than 20% is evaluated as "○", and the case where the rate of change of surface resistivity is 20% or more is evaluated as "×". When the rate of change of surface resistivity is "◎" or "○", it means that the surface resistivity does not change significantly before and after the heat and humidity resistance test, and is practical in use.

[0607] (Measurement of reflection intensity)

[0608] The intensity of the reflected wave of the sample and the frequency band where the reflection intensity is -30 dB or more are measured according to the method for measuring the reflection amount described in JIS R1679: 2007. The sample is arranged in a flat state on the sample stand, and the transmitting antenna and the receiving antenna are arranged according to the incident angle θ1 and the reflection angle θ2 (θ1, θ2 = 45 degrees) of the radio wave. The distance between the sample and the receiving antenna and the distance between the sample and the transmitting antenna are set to 1m. Radio waves with a frequency varying from 3 GHz to 300 GHz (3 GHz radio waves, 5 GHz radio waves, and radio waves with a scale of 30 GHz to 300 GHz (i.e., 30, 60, 90, 120 ... 300 GHz)) are output from the transmitting antenna, and the reflection amount (reflection intensity) of the radio waves is measured. In addition, the frequency band where the reflection amount is -30 dB or more is obtained.

[0609] First, place a reference metal plate (aluminum A1050 plate, thickness 3mm) on the sample stand, and use a scalar network analyzer to measure and record the receiving level. At this time, use a scalar network analyzer to directly connect the coaxial cables of the receiving antenna and the transmitting antenna, and correct the signal level at each frequency to 0. Then, reassemble the device and perform the measurement. Remove the reference metal plate from the sample stand, place the sample on the sample stand, and measure and record the receiving level. Subtract the receiving level of the reference metal plate from the measured receiving level to calculate the reflection amount in the regular reflection direction of the radio wave reflector 11 of the measured object. Repeat the same measurement for each sample. It should be noted that when the frequency of the radio wave is below 10 GHz, consider the first Fresnel radius of the rectangular horn antenna, and appropriately use a millimeter wave lens to irradiate the sample with a plane wave.

[0610] (Difference in reflection intensity)

[0611] In the radio wave reflector 11 before and after the heat and humidity resistance test, the reflection intensity of the radio wave (3GHz radio wave, 5GHz radio wave, 30GHz or more with 30GHz as the scale to 300GHz (i.e., 30, 60, 90, 120 ... 300GHz)) whose frequency is changed from 3GHz to 300GHz is obtained. Next, for each frequency, the difference (absolute value) of the radio wave reflection intensity before and after the heat and humidity resistance test is obtained. The maximum value of the difference is shown in Table 3. If the difference (absolute value) is less than 2, it means that the reflection intensity of the radio wave reflector 11 is not reduced, and it is practical in use.

[0612] (Test results)

[0613] The test results are shown in Table 3. In Example 21 and Example 22, the conductor 12 is formed at a position 10 mm and 5 mm further inside than the end edge 13a of the substrate 13 of the laminate 18, respectively. The difference in yellow index before and after the heat and humidity resistance test is as small as 0.4 and 0.6, respectively. In addition, the rate of change of the surface resistivity is evaluated as "◎". In addition, in all frequency bands above 3 GHz and below 300 GHz, the reflection intensity of the radio wave reflector 11 before and after the heat and humidity resistance test of Example 21 is -20 dB. The difference in reflection intensity is zero, and the reflection intensity is not reduced at all. In this way, in Example 21 and Example 22, no degradation was found before and after the heat and humidity resistance test.

[0614] In Example 26, the conductor 12 is formed 1 mm inside the edge of the laminate 18, and the difference in yellowness index is 3.2, which is greater than that in Example 21. Among them, the rate of change of the surface resistivity is evaluated as "○". In the frequency band of 3 GHz to 300 GHz, at a frequency of 27.5 GHz, the reflection intensity of the radio wave reflector 11 before the heat and humidity resistance test is -20 dB, and the reflection intensity after the heat and humidity resistance test is -21 dB, and the difference in reflection intensity is 1. The reflection intensity is slightly reduced, but it is practical in use.

[0615] In Examples 23 to 25, the conductor 12 is formed at the edge 13a of the substrate 13 of the laminate 18, but the conductor 12 is covered by the sealing material 17. Examples 23 to 25 use polysiloxane resin, acrylic resin, and epoxy resin as the sealing material 17. The difference in the yellow index of Examples 23 to 25 is as small as 0.1, and the change rate of the surface resistivity is evaluated as "◎". In addition, in all frequency bands above 3 GHz and below 300 GHz, the reflection intensity of the radio wave reflector 11 before and after the heat and humidity resistance test of Example 21 is -20 dB. The difference in reflection intensity is zero, and the reflection intensity is not reduced at all.

[0616] In contrast, in Comparative Example 1, the conductor 12 is formed at the edge 13a of the substrate 13 of the laminate 18, the sealing material 17 is not provided, and the conductor 12 is exposed to the outside. The difference in yellow index is as large as 4.0, and the rate of change in surface resistivity is evaluated as "×". In the frequency band from 3 GHz to 300 GHz, at a frequency of 27.5 GHz, the reflection intensity of the radio wave reflector 11 before the heat and humidity resistance test is -20 dB, and the reflection intensity after the heat and humidity resistance test is -25 dB, and the difference in reflection intensity is 5, which means that the reflection intensity is greatly reduced.

[0617] [Table 3]

[0618]

[0619] <Modification>

[0620] The above-mentioned embodiment is only one of various embodiments of the present invention. As long as the purpose of the present invention can be achieved, various changes can be made to the embodiment according to the design, etc. The following are modified examples of the embodiment. The modified examples described below can be appropriately combined and applied.

[0621] (1) Modification 1

[0622] The conductive layer 16 may have a metamaterial structure, for example. The metamaterial structure is a structure in which sheet-shaped conductors 12 as dielectrics are arranged periodically and uniformly. The periodic arrangement structure has a negative dielectric constant and reflects radio waves belonging to a specific frequency band determined based on the periodic interval. The shape of each conductor 12 is not limited and may be the above-mentioned shape, for example, Fig. 9 As shown, each conductor 12 may also be square. The length L20 of one side and the interval L21 between adjacent conductors 12 may also be set in such a way that the conductor 12 reflects radio waves with a frequency of more than 3 GHz and less than 300 GHz. In this case, the length L20 of one side of the conductor 12 may be more than 0.7 mm and less than 800 mm, and the interval L21 may be more than 1 μm and less than 1000 μm. The thickness L3 of the conductor 12 is preferably less than 350 nm (0.35 μm), more preferably less than 100 nm, and further more preferably less than 50 nm. The number of conductors 12 is appropriately set according to the size (area) of the substrate 13. In one example, the conductor 12 may also be formed on the substrate 13 in two longitudinal directions and two in the transverse direction, for a total of four, according to the size of the substrate 13. In this case, the length L20 of one side of each conductor 12 is set to 77.460 mm, the interval L21 between adjacent conductors 12 is set to 100 μm, and the thickness L3 is set to 350 nm (0.35 μm) or less. The conductive layer 16 is not limited to a metamaterial structure, and may be any of a metal nanowire laminate film, multilayer graphene, and partially exfoliated graphite.

[0623] (2) Modification 2

[0624] like Fig.10 As shown, the radio wave reflector 11 may also be stacked in multiple layers in the vertical direction. For example, another conductive layer 16B is bonded to the conductive layer 16A via the adhesive layer 14A, and a protective layer 15 is bonded to the conductive layer 16B via the adhesive layer 14B. It should be noted that the conductive layer 16A includes the base material 13 and the conductor 12 in the same manner as in the embodiment. The conductive layer 16B also includes the base material 13 and the conductor 12.

[0625] It should be noted that the conductor 12 formed in the conductive layer 16 may be stacked in three or more layers. If the number of stacked conductors 12 increases, the reflection intensity increases, but the thickness of the radio wave reflector 11 as a whole becomes thicker, so the flexibility decreases, and the visible light transmittance also decreases. Therefore, in particular, when the radio wave reflector 11 is set in a place where flexibility and transparency are not required, the number of stacked layers is increased, and the number of stacked layers is appropriately set according to the use purpose, etc.

[0626] (3) Modification 3

[0627] The conductor 12 may be, for example, Fig.11 The conductor 12 is formed in a pattern in which the first conductive portion 4 including a plurality of first surrounding portions 41 and the second conductive portion 5 including a plurality of second surrounding portions 51 overlap. The first surrounding portion 41 and the second surrounding portion 51 do not have a common portion when projected onto a projection plane parallel to the conductive layer.

[0628] The first conductive portion 4 is formed by repeating at a certain pitch the first surrounding portions 41 surrounding the first region R1 where the conductor 12 is not formed. Here, the first conductive portion 4 is formed in a lattice shape, but may be formed in a pentagonal, hexagonal, circular, or the like.

[0629] The second conductive portion 5 is repeatedly formed with a second enclosing portion 51 at a certain interval, which surrounds the fourth region R4, an area where the conductor 12 is not formed. The fourth region R4 is formed in a manner spanning multiple adjacent first regions R1. The second conductive portion 5 can be located on the same plane as the first conductive portion 4, or on a different plane. That is, the second conductive portion 5 can be conductive with the first conductive portion 4, or not. In addition, adjacent second conductive portions 5 are separated from each other, but can also be in contact. It should be noted that the second conductive portion 5 is formed in a quadrilateral shape, but can also be formed in a pentagonal shape, a hexagonal shape, etc. It should be noted that, Fig.11 , described later Fig.12 The top view shows the arrangement of the conductor 12 , but the protective layer 15 and the adhesive layer 14 are not shown.

[0630] The electric conductor 12 of the modification 3 can improve the diffusibility of radio waves. The "radio wave diffusibility" mentioned here means that the difference between the regular reflection intensity and the radio wave intensity around the regular reflection falls within a certain range.

[0631] (4) Modification 4

[0632] The conductor 12 may be, for example, Fig.12 The form shown. Fig.12 The form and Fig.11Compared with the morphology of the first conductive portion 4, the shape of the second conductive portion 5 (second enclosing portion 51) is different, and the second enclosing portion 51 is circular. The center point of the second enclosing portion 51 is arranged in a manner overlapping with the intersection of the first conductive portion 4 formed in a lattice shape, and the diameter of the second enclosing portion 51 is equal to the lattice spacing of the first conductive portion 4. That is, adjacent second enclosing portions 51 are in contact with each other. It should be noted that adjacent second enclosing portions 51 can also be separated from each other. The other structures are the same as those of Modification Example 3, so the corresponding structures are marked with the same figure marks and the description is omitted.

[0633] Thus, by having the circular second surrounding portion 51, the influence of the incident direction on the reflection intensity with respect to the radio wave reflector 11 can be reduced in a plan view. In other words, in this case, in a plan view, no matter from which direction the radio wave is incident on the radio wave reflector 11, the change in diffusivity corresponding to the incident direction can be reduced.

[0634] (5) Modification 5

[0635] The conductive layer 16 of the radio wave reflector 11 may not include the base material 13. In this case, all the conductors 12 of the conductive layer 16 are supported by the adhesive layer 14 and the protective layer 15, and in the top view, all the conductors 12 of the conductive layer 16 are covered by the adhesive layer 14 and the protective layer 15. It should be noted that when the protective layer 15 has adhesiveness, only the protective layer 15 may be provided. In other words, the protective layer 15 may also support the conductor 12 as the base material 13.

[0636] Such a radio wave reflector 11 is arranged so that the conductor 12 faces the installation surface of the installation part, and the conductor 12 is in direct contact with the installation surface or in contact with it via an adhesive layer, etc. The conductor 12 is covered by the adhesive layer 14 and the protective layer 15 and the installation surface in a plan view, and the conductor 12 is not exposed to the outside to prevent degradation.

[0637] (6) Others

[0638] In the above-mentioned embodiment, the radio wave reflector 11 is formed into a sheet shape, but the present invention is not limited thereto, and may be, for example, a plate shape, a block shape, a spherical shape, a box shape, etc. In addition, the installation object of the radio wave reflector 11 is not limited to building materials, and may be an electrical product, a building structure, a car, a tram, an airplane, etc.

[0639] In the above-described embodiment, the radio wave reflector 11 includes the adhesive layer 14 between the conductive layer 16 and the protective layer 15, but as long as the protective layer 15 has self-adhesive strength, the adhesive layer 14 may not be present. In addition, the protective layer 15 may be fixed to the conductive layer 16 independently of the adhesive layer 14 by sealing the outer edge portion with a sealing material. It should be noted that the protective layer 15 does not necessarily need to be fixed to the conductive layer 16.

[0640] Above, an embodiment of the present invention has been described, but the present invention is not limited to the embodiment, and various changes can be made as long as it does not deviate from the main purpose of the present invention. The size, material, shape, relative configuration, etc. of the components recorded as an embodiment or shown in the drawings are not intended to limit the scope of the present invention to this, but are only illustrative examples. For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configurations not only strictly indicate such configurations, but also indicate a state of relative displacement at an angle or distance with a tolerance or a degree that can obtain the same function. For example, expressions such as "same", "equal" and "homogeneous" that indicate the state of equality of things not only indicate a strictly equal state, but also indicate a state of difference in the degree that there is a tolerance or the degree that can obtain the same function. For example, expressions indicating shapes such as quadrilaterals and cylindrical shapes not only indicate shapes such as quadrilaterals and cylindrical shapes in a strict sense of geometry, but also indicate shapes including concave-convex parts, chamfered parts, etc. within the range that can obtain the same effect. "Having", "having", "having", "including" or "having" a constituent element such as such expressions are not exclusive expressions that exclude the existence of other constituent elements.

[0641] In this specification, expressions accompanied by "approximately" such as "approximately parallel" or "approximately orthogonal" are sometimes used. For example, "approximately parallel" means substantially "parallel," and not only the state of "parallel" in a strict sense, but also includes an error of several degrees. The same applies to other expressions accompanied by "approximately".

[0642] In addition, in this specification, expressions distinguished by the presence or absence of "part" are used, such as "end" and "end". For example, "end" means the end of an object, and "end" means an area with a certain range including the "end". If it is a point within a certain range including the end, it is set as "end". The same applies to other expressions with "part".

[0643] Explanation of symbols

[0644] 11 Radio wave reflector

[0645] 12 Conductors

[0646] 12a The first region (region without conductor)

[0647] 12b The second region (region without conductor)

[0648] 12c The third region (region without conductors)

[0649] 13. Substrate

[0650] 14 Adhesive layer

[0651] 15. Protective layer

[0652] 16 Conductive layer

[0653] 17 Sealing material

[0654] 18 Laminated body

Claims

1. A radio wave reflector comprising: a conductive layer including a conductor that reflects electric waves; and a protective layer that protects the conductive layer, When the radio wave reflector is subjected to a pencil hardness test, the pencil hardness under the condition that the surface load of the protective layer is 500 g is F or more.

2. The radio wave reflector according to claim 1, wherein: The thickness of the protective layer is greater than 38 μm.

3. The radio wave reflector according to claim 1 or 2, wherein: When the protective layer is subjected to a pencil hardness test, the pencil hardness under a condition where the surface load of the protective layer is 500 g is F or more.

4. The radio wave reflector according to any one of claims 1 to 3, further comprising: an adhesive layer, which is disposed between the conductive layer and the protective layer to bond the conductive layer and the protective layer, The adhesive layer has a hydroxyl value of 5 mgKOH / g or more.

5. The radio wave reflector according to any one of claims 1 to 4, further comprising: an adhesive layer, which is disposed between the conductive layer and the protective layer to bond the conductive layer and the protective layer, The acid value of the adhesive layer is 50 mgKOH / g or less.

6. The radio wave reflector according to any one of claims 1 to 5, wherein The moisture permeability of the protective layer at 40°C and 90% rh is 20 g / m 2 Less than 24 hours.

7. The radio wave reflector according to any one of claims 1 to 6, wherein The adhesive force of the protective layer to the adherend layer decreases by 50% or less after a heat and humidity resistance test.

8. The radio wave reflector according to any one of claims 1 to 7, wherein The total light transmittance of the radio wave reflector is greater than 70%.

9. The radio wave reflector according to any one of claims 1 to 8, further comprising: an adhesive layer, which is disposed between the conductive layer and the protective layer to bond the conductive layer and the protective layer, In the radio wave reflector, the adhesive layer does not contain an ultraviolet ray inhibitor.

10. The radio wave reflector according to any one of claims 1 to 9, wherein The conductive layer has: an area without said electrical conductor; and the conductor being formed so as to surround the region, The region includes a plurality of regions of the same shape, The plurality of regions of the same shape are arranged at regular intervals.

11. The radio wave reflector according to any one of claims 1 to 10, wherein The surface resistivity of the radio wave reflector after the heat and humidity resistance test is 100Ω / □ or less.

12. The radio wave reflector according to any one of claims 1 to 11, wherein The protective layer contains at least one of an anti-ultraviolet agent and an anti-ultraviolet treatment is applied to the surface.

13. The radio wave reflector according to any one of claims 1 to 12, wherein The radio wave reflector has a haze of 30% or less.

14. The radio wave reflector according to any one of claims 1 to 13, wherein The total light transmittance of the radio wave reflector after the light resistance test is 70% or more.

15. The radio wave reflector according to any one of claims 1 to 14, wherein The yellowing degree Δb* of the radio wave reflector before and after the light resistance test is 15 or less.

16. The radio wave reflector according to any one of claims 1 to 15, comprising: a laminated body in which the protective layer and the conductive layer are laminated; When viewed from above, all of the electrical conductors are covered by the protective layer.

17. The radio wave reflector according to claim 16, wherein: The laminate further comprises an adhesive layer for bonding the protective layer and the conductive layer. The conductor is arranged inside the edge of the protective layer when viewed from above, The conductor is covered by the adhesive layer when viewed from the side.

18. The radio wave reflector according to claim 17, wherein: The conductive layer further comprises a substrate supporting the conductor, The conductor is located between the substrate and the protective layer, and is arranged on the inner side than the edge of the substrate when viewed from above.

19. The radio wave reflector according to any one of claims 16 to 18, wherein The conductor is arranged at an inner side of 5 mm or more from an edge of the protective layer when viewed from above.

20. The radio wave reflector according to any one of claims 16 to 19, wherein A sealing material is provided at least at a position corresponding to the conductive layer around the laminate so as to prevent the conductive body from being exposed.

21. The radio wave reflector according to any one of claims 16 to 20, wherein The difference between the yellowness index after the heat and humidity resistance test and the yellowness index before the heat and humidity resistance test is 3 or less, The heat and humidity resistance test is a test in which the radio wave reflector is placed in a constant temperature and humidity chamber adjusted to a temperature of 60° C. and a humidity of 95% RH for 500 hours, the radio wave reflector is taken out of the chamber, and left to stand at room temperature for 4 hours.

22. The radio wave reflector according to any one of claims 1 to 21, wherein When an incident wave with a frequency of 3 GHz to 300 GHz is orthographically reflected by the radio wave reflector after the heat and humidity resistance test and the radio wave reflector before the heat and humidity resistance test, there is at least one frequency of the incident wave such that the difference between the intensity of the reflected wave by the radio wave reflector after the heat and humidity resistance test and the intensity of the reflected wave by the radio wave reflector before the heat and humidity resistance test is within 3 dB, The heat and humidity resistance test is a test in which the radio wave reflector is placed in a constant temperature and humidity chamber adjusted to a temperature of 60° C. and a humidity of 95% RH for 500 hours, the radio wave reflector is taken out of the chamber, and left to stand at room temperature for 4 hours.

23. A method for manufacturing a radio wave reflector, which is the method for manufacturing a radio wave reflector according to claim 20, wherein: The manufacturing method comprises: a step of forming the laminate; and A step of providing a sealing material for preventing the conductor from being exposed, The sealing material of the radio wave reflector is located at a position around the laminate at least corresponding to the conductive layer.

24. A method for constructing a radio wave reflector, which is the method for constructing a radio wave reflector according to claim 20, wherein: The construction method comprises: A step of installing the laminate at a location; and A step of providing a sealing material for preventing the conductor from being exposed, The sealing material of the radio wave reflector is located at a position around the laminate at least corresponding to the conductive layer.

25. The method for constructing a radio wave reflector according to claim 24, wherein: In the installation step, a plurality of the stacked bodies are installed at a location at intervals. In the step of providing the sealing material, the sealing material is provided in a space between adjacent stacked bodies when the plurality of stacked bodies are installed at a location with a certain interval therebetween.

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