Resin molded body and its manufacturing method

Abstract

Provided is a resin molded body that contains resin and a conductive member having a coil shape which has a center axis, the resin molded body having a flat surface in at least a section thereof, wherein the average angle of an angle formed by the flat surface and the center axis is at least 50°.

Description

[Technical Field]

[0001] The present invention relates to a resin molded article and a method for producing the same. [Background technology]

[0002] Communication devices such as mobile phones and smartphones enable wireless communication using electromagnetic waves, and as technology in this field advances, the frequency bands of the electromagnetic waves used are expanding. In particular, development is underway to increase the speed, capacity, and latency of communication devices, and the use of electromagnetic waves in higher frequency bands is attracting attention to achieve this goal. However, because general electronic devices are vulnerable to electromagnetic waves, there is concern that higher frequencies of electromagnetic waves used may make electronic devices more susceptible to malfunction. One solution to this problem is the use of electromagnetic shields that can block electromagnetic waves. By surrounding electronic devices with electromagnetic shields, for example, the effects of surrounding electromagnetic waves can be reduced, preventing malfunctions.

[0003] There are various types of electromagnetic wave shields, and extensive research is being conducted on them. As a result of this research, it has been reported that it is effective to use a substance having a structure one order of magnitude smaller than the wavelength of the electromagnetic wave to be shielded, and as a means of forming such a structure, development of materials containing small fillers is being conducted. Patent Document 1 discloses an electromagnetic wave shield that has excellent electromagnetic wave shielding properties at a frequency of 1 GHz, and that is made of a composite having an insulating layer and a conductive layer in which flaky silver powder having a specific particle size and bulk density is impregnated in a binder resin. Patent Document 2 also discloses an electromagnetic wave shield that is made of a composite in which ferrite particles that are single crystals and have a spherical particle shape and have a specific average particle size are impregnated in a binder resin, and that is capable of blocking electromagnetic waves in the 1 MHz to 1 GHz frequency band. Patent Document 3 also discloses an electromagnetic wave shield that is made of a composite in which a specific amount or more of nickel nanowires is impregnated in a binder resin, and that is easy to handle and flexible, and that is capable of blocking electromagnetic waves in the 18.0 to 26.5 GHz frequency band. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-86930 [Patent Document 2] International Publication No. 2017 / 212997 [Patent Document 3] Japanese Patent Application Publication No. 2019-67997 Summary of the Invention [Problem to be solved by the invention]

[0005] For communication devices such as mobile phones and smartphones, wireless communication systems that comply with the IMT-Advanced standard established by the International Telecommunication Union (ITU) are specified, and the frequency band, which was approximately 800 MHz in the first-generation mobile communication system (1G), has been expanded to approximately 3 GHz in the fourth-generation mobile communication system (4G).The currently adopted fifth-generation mobile communication system (5G) has expanded the frequency band to the 28 GHz band, and currently, development is underway for the sixth-generation mobile communication system (6G), which will use frequency bands above 100 GHz as the next-generation communication system. The electromagnetic wave shields disclosed in the above Patent Documents 1 to 3 cannot handle electromagnetic waves in the frequency bands of next-generation wireless communication systems, which are an order of magnitude or more larger than the frequency bands used in previous wireless communication systems, and there is a demand for the development of high-performance electromagnetic wave shields that can handle electromagnetic waves in such frequency bands.

[0006] Therefore, an object of the present invention is to provide a resin molded product (particularly an electromagnetic wave shielding sheet) that can shield electromagnetic waves in the high frequency band, and a method for producing the same. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors discovered that the above problems can be solved by using a molded body in which a coil-shaped conductive member is contained in a resin, and thus arrived at the present invention.

[0008] [1] A resin molded body including a resin and a conductive member having a coil shape with a central axis, and having a flat surface on at least a portion thereof, The average angle between the plane and the central axis is 50° or more. [2] The resin molded product according to [1], wherein the coil shape is a spiral. [3] The resin molded body according to [2], wherein the conductive member is a metal coil. [4] The resin molded body described in [1], wherein the conductive member is composed of a plurality of C-shaped conductive materials and a columnar conductive material that connects the ends of the plurality of C-shaped conductive materials in the central axis direction. [5] the resin molded body The content of the conductive material in the 3 More than 5.50g / cm 3 The resin molded article according to any one of [1] to [4] below. [6] The resin molded product according to any one of [1] to [5], which is in the form of a sheet. [7] The resin molding according to [6], which is an electromagnetic wave shielding sheet. [8] A conductive member having a coil shape with a resin and a central axis, and at least A method for manufacturing a resin molded product having a flat surface at least in part, comprising: a pocket resin member fabrication step of fabricating a resin member having a pocket and at least a flat surface on a portion thereof; a conductive member placement step of orienting and placing the conductive member in the pocket; and a pocket resin curing step of pouring a resin-containing composition into the pocket in which the conductive member is disposed and then curing the composition; and A method for producing a resin molded article, wherein the average angle formed between the plane and the central axis is 50° or more. [9] A method for producing a resin molded product, the resin molded product including a resin and a conductive member having a coil shape with a central axis, and at least a flat surface, comprising: The resin, the C-shaped conductive material, and the C-shaped Conductive materials A C-shaped conductive material-containing resin sheet manufacturing process for manufacturing a plurality of resin sheets each having a columnar conductive material connected to an end portion thereof; a lamination step of laminating a plurality of resin sheets so that an end of the C-shaped conductive material on one sheet and a column-shaped conductive material on the other sheet are in contact with each other in the central axis direction; A method for producing a resin molded product, comprising:

[10] A method for producing a resin molded product, the resin molded product including a resin and a conductive member having a coil shape with a central axis, and at least a flat surface, comprising: a conductive member-containing resin composition preparation step of preparing a resin composition containing the resin and a composition containing the conductive member; an orientation step of orienting the conductive member so that the average angle between the planar direction of the sheet and the central axis is 50° or more; a curing step of curing the conductive member-containing resin composition while maintaining the orientation of the conductive members; A method for producing a resin molded product, comprising:

[11] The method for producing a resin molded article according to any one of [8] to

[10] , wherein the resin molded article is in the form of a sheet.

[12] The method for producing a resin molded product according to

[11] , wherein the resin molded product is an electromagnetic wave shielding sheet.

[0009]

[13] A resin molded product comprising a resin and a conductive coil, wherein the conductive member constituting the conductive coil is spiral-shaped.

[14] the resin molded body The content of the conductive coil in the 3 More than 5.00g / cm 3 The resin molded article according to

[13] , wherein the resin molded article is less than 100%.

[15] The resin molded product according to

[13] or

[14] , which is in the form of a sheet.

[16] The resin molding according to

[15] , which is an electromagnetic wave shielding sheet.

[17] A method for producing a resin molded product comprising a resin and a conductive coil, a conductive coil-containing resin composition curing step of preparing a resin composition containing the resin and a composition containing the conductive coil, and then curing the composition; and The conductive member constituting the conductive coil is spiral. A method for manufacturing a resin molded product.

[18] The method for producing a resin molded product according to

[17] , wherein the resin molded product is in the form of a sheet. Law.

[19] The method for producing a resin molded product according to

[18] , wherein the resin molded product is an electromagnetic wave shielding sheet.

[20] A composition for a resin molding, comprising a resin and a conductive coil, wherein the conductive member constituting the conductive coil is spiral-shaped.

[21] The composition for a resin molding according to

[20] , which is a composition for an electromagnetic wave shielding sheet.

[22] A telecommunications device comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[23] A consumer electronic device comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[24] An automotive device comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[25] A medical device comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[26] An aerospace device comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[27] A defense device comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[28] A system comprising the resin molded article according to any one of [1] to [7] and

[13] to

[16] .

[29] A digital weapon comprising a resin molded article according to any one of [1] to [7] and

[13] to

[16] . [Effects of the Invention]

[0010] The present invention provides a resin molding (particularly an electromagnetic wave shielding sheet) capable of shielding electromagnetic waves in the high-frequency band, and a method for producing the same. In particular, in certain embodiments, the molding is advantageous in shielding electromagnetic waves having frequencies of 100 GHz or higher. Furthermore, in certain embodiments, the molding is advantageous in shielding electromagnetic waves at frequencies of 100 GHz or higher, in the 200 to 400 GHz frequency band on the high-frequency side of 5G and 6G, and even in the higher frequency bands expected to be used in the generation after 6G. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram schematically illustrating one embodiment of a conductive member. [Figure 2] 10 is a diagram for explaining an angle θ formed between the central axis of the conductive member and the plane of the sheet. FIG. [Figure 3] FIG. 2 is a diagram illustrating the configuration of a conductive member. [Figure 4] FIG. 1 is a diagram schematically illustrating an experimental device for evaluating electromagnetic wave shielding properties. [Figure 5] FIG. 1 is a diagram schematically illustrating one embodiment of a member having a pocket in which a conductive member is disposed. [Figure 6]FIG. 1 is a diagram schematically illustrating one embodiment of a resin sheet having a C-shaped conductive material and a columnar conductive material connected to an end of the C-shaped conductive material. [Figure 7] FIG. 1 is a diagram showing a schematic representation of one embodiment of a laminated sheet formed by laminating resin sheets having a C-shaped conductive material and a columnar conductive material connected to the end of the C-shaped conductive material. [Figure 8] 1A to 1C are diagrams schematically illustrating one embodiment of a method for producing a resin molded body. [Figure 9] FIG. 10 is a diagram showing the setting conditions for the simulation in Experiment A1 (x-axis tilt experiment) of the example. [Figure 10] FIG. 10 is a diagram showing the results of a simulation (θ=0 to 30°) in Experiment A1 (x-axis tilt experiment) of the example. [Figure 11] FIG. 10 is a diagram showing the results of a simulation (θ=20 to 50°) in Experiment A1 (x-axis tilt experiment) of the example. [Figure 12] FIG. 10 is a diagram showing the results of a simulation (θ=40 to 70°) in Experiment A1 (x-axis tilt experiment) of the example. [Figure 13] FIG. 10 is a diagram showing the results of a simulation (θ=60 to 90°) in Experiment A1 (x-axis tilt experiment) of the example. [Figure 14] FIG. 10 is a diagram showing the setting conditions for the simulation in Experiment A1 (y-axis tilt experiment) of the example. [Figure 15] FIG. 10 is a diagram showing the results of a simulation (θ=0 to 30°) in Experiment A1 (y-axis tilt experiment) of the example. [Figure 16] FIG. 10 is a diagram showing the results of a simulation (θ=20 to 50°) in Experiment A1 (y-axis tilt experiment) of the example. [Figure 17] FIG. 10 is a diagram showing the results of a simulation (θ=40 to 70°) in Experiment A1 (y-axis tilt experiment) of the example. [Figure 18] FIG. 10 is a diagram showing the results of a simulation (θ=60 to 90°) in Experiment A1 (y-axis tilt experiment) of the example. [Figure 19] 10 is a diagram showing a method for producing a continuous horizontal coil of Comparative Example A2 in Experiment A2 of the embodiment. FIG. [Figure 20] FIG. 2 is a diagram schematically illustrating an embodiment of a conductive coil. [Figure 21] This is a scanning electron microscope image of a conductive coil (photograph used as a drawing). [Figure 22] FIG. 2 is a diagram schematically illustrating an embodiment of a conductive coil. [Figure 23] FIG. 2 is a diagram illustrating the shape of a conductive coil. [Figure 24] FIG. 10 is a diagram schematically illustrating a method for producing the electromagnetic wave shielding sheet in Example B1. [Figure 25] FIG. 10 is a diagram showing an embodiment of a simulation in Reference Experiment B1 (vertical direction experiment) of the example. [Figure 26] FIG. 10 is a diagram showing parameters A to C in reference experiment B1 (vertical direction experiment) of the example. [Figure 27] FIG. 10 is a diagram showing the simulation results of Level 1 in Reference Experiment B1 (vertical direction experiment) of the example. [Figure 28] FIG. 10 is a diagram showing an embodiment of a simulation in Reference Experiment B1 (horizontal direction experiment) of the example. [Figure 29] FIG. 10 is a diagram showing a parameter θX in a reference experiment B1 (horizontal direction experiment) of the embodiment. [Figure 30] FIG. 10 is a diagram showing the simulation results of level 5 in reference experiment B1 (horizontal direction experiment) of the example. DETAILED DESCRIPTION OF THE INVENTION

[0012] While the embodiments of the present invention will be described in detail below, the configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate within the scope of the gist of the present invention. The present disclosure is not limited to the embodiments, but is limited only by the scope of the claims. In this disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits, and "A to B" means A or more and B or less. Also, in this disclosure, "plurality" means "two or more."

[0013] <First resin molded body> The first resin molding will be described in detail below. <Structure and characteristics of resin molded body> A first resin molded body according to an embodiment of the present disclosure (also simply referred to as a "resin molded body" in the description of this embodiment) includes a resin and a conductive member having a coil shape with a central axis, and has a flat surface on at least a portion thereof, The resin molded article has an average angle between the plane and the central axis of 50° or more.

[0014] The inventors focused on a coil shape with a central axis as a structure that can obtain strong absorption of electromagnetic waves in the terahertz region. The coil-shaped material can control polarization. When linearly polarized incident electromagnetic waves are incident on the coil-shaped material, the polarization becomes elliptically polarized and is emitted. In this way, the coil-shaped material can be used to control polarization. In this embodiment, we focused on the magnitude of the coil-shaped electromagnetic wave absorption, rather than polarization control. Furthermore, the inventors have noticed that one turn of the coil shape can be regarded as an LC resonant circuit. In this case, when the transmittance of the material of the coil shape is examined, the effect of absorbing electromagnetic waves is obtained by LC resonance, with the gap of the coil shape as capacitance C and the coil shape itself as inductance L. Then, by increasing the number of turns of the coil shape, the electromagnetic waves Absorption of It was thought that this could increase the effect of The effect of absorbing electromagnetic waves by the LC resonance is also greatly affected by the angle between the central axis of the coil and the electromagnetic waves. Specifically, when the angle is 90°, the effect of absorbing electromagnetic waves is small, whereas when the angle is 0°, the effect of absorbing electromagnetic waves is large. The inventors focused on the above points and discovered that by making the shape of the conductive member contained in the resin coil-shaped and incorporating the conductive member in the resin (particularly a sheet-shaped resin) having a flat surface in at least a portion thereof into the resin so that the average value of the angle between the central axis of the coil shape and the direction of the flat surface is a specific angle or more, it is possible to produce a resin molded body member (particularly a sheet member) that has excellent electromagnetic wave shielding properties even against high-frequency electromagnetic waves, and thus completed the present invention. In this disclosure, unless otherwise specified, the direction of external electromagnetic waves will be described as being perpendicular to the plane (particularly the sheet plane) of a resin molded body (particularly an electromagnetic wave shielding sheet) having a flat surface in at least a portion thereof.

[0015] The shape of the resin molded body is not particularly limited as long as it has a flat surface at least in part, and the position of the flat surface is not particularly limited, but it is preferable to form the resin molded body so that the normal direction of the flat surface is the incident direction of electromagnetic waves from outside, and further, when the resin molded body is to be placed on another member for use, it is preferable to form the resin molded body so that the flat surface serves as the installation surface for the other member. Specific shapes of the resin molded body include, for example, a sheet shape, a spherical shape having a flat surface on one side, a cylindrical shape or a polygonal prism shape having a flat surface on one side, etc., but from the viewpoint of ease of handling, a sheet shape is preferred. When in a sheet shape, the resin molded product according to this embodiment can be described as an electromagnetic wave shielding sheet that includes a resin and a conductive member that has a coil shape with a central axis, and the average angle between the plane of the sheet and the central axis is 50° or more.

[0016] The uses of the resin molded article are not particularly limited, and examples thereof include electromagnetic wave shielding. Hereinafter, a sheet-shaped resin molded article, particularly an electromagnetic wave shielding sheet, will be specifically described. Note that the plane of the sheet in the following description corresponds to a plane that at least a portion of the resin molded article in this embodiment has. Furthermore, to the extent applicable, the conditions for the following embodiments can also be applied to the conditions for embodiments of shapes other than sheets.

[0017] [Conductive material] (Construction of conductive member) The conductive member is not particularly limited as long as it has a coil shape with a central axis. In the present disclosure, a coil shape refers to a shape composed of a structure surrounding the central axis and a structure extending in the direction of the central axis, or a shape composed of a structure surrounding the central axis and extending in the direction of the central axis. This surrounding structure may be a structure having a circular or polygonal circumferential shape. Specific examples of the coil shape include a spiral shape with a central axis as shown in FIG. 1(a) and a shape composed of multiple C-shaped structures and columnar structures connecting the multiple C-shaped structures in the direction of the central axis as shown in FIG. 1(b). Specifically, FIG. 1(b) shows a shape composed of repeated structures in which a columnar end is connected to the end of a C-shaped structure, and then another C-shaped end is connected to the other end of the columnar shape, resulting in a shape similar to a coil as a whole. Furthermore, as shown in FIGS. 1(c) and (d), these coil-shaped conductive materials may or may not be connected by a linear conductive material. The conductive member does not necessarily have to have a straight central axis, but may have a central axis that can approximate a straight line. In the case where the central axis can approximate a straight line, the approximated straight line becomes the central axis.

[0018] When the coil shape of the conductive member is a spiral shape having a central axis as shown in FIG. 1(a), the form is not particularly limited as long as it is conductive, and for example, a metal coil can be used. While some materials with a central axis and a helical shape have no specific winding direction, i.e., some have a mixture of right- and left-handed windings, metal coils can be produced industrially and can be made with a uniform winding direction. When both right- and left-handed windings are mixed, the electromagnetic shielding effects cancel each other out, reducing the overall electromagnetic shielding effectiveness. However, when the winding direction is uniform, this cancellation does not occur. Furthermore, metal coils have the advantages of being able to precisely design the coil size, allowing for accurate control of the resonant frequency, making them usable as absorbers at various frequencies. Furthermore, they can be easily aligned in the desired configuration, making it easy to obtain strong absorption in a specific direction. Furthermore, they can be easily mass-produced as metamaterials. The cross-sectional shape of the wire that constitutes the spiral shape is not particularly limited and may be, for example, circular or polygonal such as triangular or rectangular, but is preferably circular from the viewpoint of ease of availability and ease of manufacture. As shown in Figure 1(c), multiple spirals may be connected together, and the central axes of the spirals may not necessarily be coaxial. In such a connected configuration, each spiral is treated as a single conductive member, and the angle between the central axis of each conductive member and the plane of the sheet is calculated.

[0019] When the coil shape of the conductive member is a shape composed of a plurality of C-shaped structures and a columnar structure connecting the plurality of C-shaped structures in the central axis direction as shown in Figure 1(b), the form is not particularly limited, and an example thereof is a form in which the C-shaped structure portion is made of a conductive thin film and the columnar structure portion connecting the plurality of C-shaped structures is made of a columnar conductive material, as will be described later in the description of the manufacturing method. The C-shape may be a circular ring with a portion missing, as shown in Fig. 1(b), or a polygonal ring such as a triangle or a square with a portion missing, but from the viewpoints of availability and ease of manufacture, a circular ring with a portion missing is preferable. In either case, as long as there is a central axis, the effect of absorbing electromagnetic waves by LC resonance based on external electromagnetic waves can be obtained. The columnar shape is not particularly limited and may be a cylindrical shape or a polygonal columnar shape such as a triangular columnar shape or a quadrangular columnar shape, but a cylindrical shape is preferred from the viewpoints of availability and ease of production. The C-shaped structural portion and the columnar structural portion may be made of the same material or different materials, but from the viewpoint of reducing manufacturing costs, they are preferably made of the same material. Furthermore, similar to FIG. 1(c) above, the shapes in FIG. 1(b) can be connected to form a shape as shown in FIG. 1(d), in which case the method for calculating the above angles is the same as the calculation method in FIG. 1(c) above.

[0020] The type of material for the conductive member is not particularly limited as long as it is conductive, and examples thereof include carbon materials such as carbon, copper (Cu), aluminum (Al), iron (Fe), gold (Au), silver (Ag), platinum (Pt), magnesium (Mg), zinc (Zn), tungsten (W), titanium (Ti), nickel (Ni), or manganese (Mn), alloys made of combinations of these metal elements, or metal-containing compounds such as oxides, halides, or sulfides of these metal elements or alloys. Copper (Cu) and iron (Fe) are preferred, and tungsten (W) is particularly preferred, from the viewpoint of good durability of the resin sheet, as they have an elastic modulus suitable for coil processing, good corrosion resistance when contained in a resin, and a small linear expansion coefficient.

[0021] The content of the conductive material in the sheet is not particularly limited, but from the viewpoint of improving the electromagnetic wave shielding property, the content per volume of the sheet is usually 0.00040 g / cm 3 or more, 0.001 g / cm 3It is preferable that the concentration is 0.01 g / cm or more. 3 More preferably, it is 0.05 g / cm or more. 3 More preferably, it is 0.075 g / cm or more. 3 It is particularly preferable that the concentration is 0.10 g / cm or more. 3 It is most preferable that the density is 5.50 g / cm or more, and usually 5.50 g / cm 3 less than or equal to 3.00 g / cm 3 Preferably, it is 1.00 g / cm or less. 3 More preferably, it is 0.50 g / cm or less. 3 More preferably, it is 0.30 g / cm or less. 3 More preferably, it is 0.26 g / cm or less. 3 It is even more preferable that:

[0022] In the electromagnetic wave shield of this embodiment, the average angle between the central axis of the conductive member and the plane of the sheet is equal to or greater than a specific angle, and therefore the electromagnetic wave shielding property is superior to that of an electromagnetic wave shield manufactured with the same conductive member content as in the embodiment but without oriented conductive members. Therefore, when trying to achieve the same level of electromagnetic wave shielding property between the electromagnetic wave shield of this embodiment and an electromagnetic wave shield manufactured without oriented conductive members, the electromagnetic wave shield of this embodiment can use less conductive member. Since conductive members are usually more expensive per volume than resins, the electromagnetic wave shield of this embodiment has lower material costs than an electromagnetic wave shield manufactured without oriented conductive members.

[0023] The angle between the central axis of the conductive member and the plane of the sheet is the angle θ shown in Figure 2. The arrow X in Figure 2 indicates the plane direction of the sheet. Also, Figure 2 shows an embodiment of the conductive material having a spiral shape with a central axis as shown in Figure 1(a), but the angle between the central axis of the conductive member and the plane of the sheet can be calculated in the same way for other embodiments. The larger the angle θ, the greater the effect of absorbing electromagnetic waves due to LC resonance based on external electromagnetic waves, and the greater the electromagnetic wave shielding effect. In particular, the electromagnetic wave shielding effect is greatly improved at angles of 50° or more. From the viewpoint of ensuring sufficient electromagnetic wave shielding properties, the average angle between the plane of the sheet and the central axis is not particularly limited as long as it is 50° or more, and is preferably 60° or more, more preferably 70° or more, even more preferably 80° or more, particularly preferably 85° or more, and theoretically most preferably 90°. The average angle is the average value of the angles between the central axes of each conductive member present in the sheet and the plane of the sheet. The above angle can be measured by internal observation using CT-X-ray.

[0024] When multiple conductive members are used, the arrangement of each conductive member is not particularly limited, but a metamaterial structure is preferable from the viewpoint of ensuring sufficient electromagnetic wave shielding. In this embodiment, the metamaterial structure refers to an embodiment in which the conductive members are aligned and arranged in the resin, more specifically, an embodiment in which the conductive members are arranged at periodic intervals in the resin. Furthermore, the arrangement is not particularly limited, and examples include an arrangement in which the conductive members are aligned to form a circle or a polygon such as a triangle or a square. This aligned arrangement may be configured in one row or two or more rows.

[0025] Figure 3 shows an example in which two conductive members, with an angle θ of 90°, are arranged parallel to one another in a resin. The top view in Figure 3 shows the conductive members observed from the direction of the central axis of the conductive members, and the bottom view in Figure 3 shows the conductive members observed from a direction 90° from the central axis. In Figure 3, l is the average outer diameter when the metal member is coil-shaped, m is the average winding pitch of the coil shape, n is the average length of the coil-shaped portion of the conductive member in the direction of the central axis, o is the average coil alignment pitch, and p is the average wire diameter of the coil shape. When multiple conductive members are used, the average outer diameter l is calculated as the average value of the multiple conductive members. In this disclosure, when the term "average" is used to refer to a parameter of a conductive member, other parameters are also calculated in the same manner as the average outer diameter. These parameters and the average number of turns of the coil shape of the conductive member can both be measured by internal observation using CT-X-rays. Note that although the above parameters are called "coils," they are not limited to coils and are parameters that apply to coil-shaped conductive members. The average coil alignment pitch is a parameter that is specified when conductive members are arranged at equal intervals, and the length of the intervals is the average coil alignment pitch. For example, when coils are arranged in a planar direction, consider a square grid of lines formed on a sheet, consisting of multiple equally spaced vertical lines and multiple equally spaced horizontal lines, with the vertical and horizontal lines spaced equally. In this case, the average coil alignment pitch is the spacing between the vertical lines (or horizontal lines) when each square contains one conductive material. Alternatively, the conductive members may be arranged at equal intervals of different lengths in multiple directions. For example, they may be arranged at equal intervals of length X vertically and length Y horizontally. In other words, the average coil alignment pitch may be determined by converting the square grid lines into rectangular grid lines. In this case, the average value of X and Y is the average coil alignment pitch.

[0026] The average outer diameter 1 of the coil shape (also simply referred to as "outer diameter of the coil shape") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 50 μm or more, preferably 75 μm or more, more preferably 100 μm or more, and even more preferably 125 μm or more, and is usually 500 μm or less, preferably 400 μm or less, more preferably 350 μm or less, even more preferably 300 μm or less, particularly preferably 250 μm or less, and most preferably 200 μm or less. Furthermore, the larger the average outer diameter, the narrower the frequency band of electromagnetic waves that can be effectively shielded.

[0027] The average winding pitch m of the coil shape (also simply referred to as "winding pitch of the coil shape") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually greater than 20 μm (greater than 20 μm), preferably 25 μm or more, more preferably 30 μm or more, and even more preferably 35 μm or more, and is usually 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 70 μm or less. Furthermore, the larger the average winding pitch, the smaller the frequency band of electromagnetic waves that can be effectively shielded.

[0028] The average length n of the coil-shaped portion in the central axis direction of the coil shape (also simply referred to as "the length of the coil-shaped portion in the central axis direction of the coil shape") is typically 20 μm or more, preferably 35 μm or more, more preferably 50 μm or more, even more preferably 100 μm or more, particularly preferably 300 μm or more, and most preferably 500 μm or more, from the viewpoint of ensuring sufficient electromagnetic wave shielding properties. Also, it is typically 10,000 μm or less, preferably 5,000 μm or less, more preferably 3,000 μm or less, and even more preferably 1,500 μm or less. Furthermore, even if the average length of the coil-shaped portion is changed, the frequency band of electromagnetic waves that can be effectively shielded does not change. Electromagnetic wave shielding performance improves as the length of the coil-shaped portion in the central axis direction of the coil shape increases.

[0029] The average coil alignment pitch o (also simply referred to as "coil alignment pitch") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 150 μm or more, preferably 200 μm or more, more preferably 300 μm or more, and even more preferably 400 μm or more. Within this range, the smaller the average coil alignment pitch, the smaller the frequency band of electromagnetic waves that can be effectively shielded. Furthermore, the coil alignment pitch is usually 3000 μm or less, preferably 2000 μm or less, more preferably 1000 μm or less, and even more preferably 750 μm or less. Within this range, the larger the average coil alignment pitch, the smaller the frequency band of electromagnetic waves that can be effectively shielded.

[0030] The average wire diameter p of the coil shape (also simply referred to as "wire diameter of the coil shape") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually greater than 1 μm (larger than 1 μm), preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more, and is usually 75 μm or less, preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. Furthermore, the larger the average wire diameter, the wider the frequency band of electromagnetic waves that can be effectively shielded.

[0031] The average number of turns (also simply referred to as "number of turns") in the coil shape of the conductive member is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 5 or more, preferably 7 or more, more preferably 10 or more, and even more preferably 14 or more, and is usually 50 or less, preferably 40 or less, more preferably 33 or less, and even more preferably 29 or less.

[0032] (Characteristics of conductive materials) Volume resistivity The volume resistivity of the conductive member is not particularly limited, and is not particularly limited as long as it is a value that allows a small current to flow. The inventors have conducted an investigation and have confirmed that there is almost no change in the resonance frequency between copper with a volume resistivity of 1.55 μΩcm (0°C) and tungsten with a volume resistivity of 4.9 μΩcm (0°C). flow An example of the value at which the volume resistivity of carbon (graphite) is 3352.8 μΩcm (20° C.).

[0033] Thermal conductivity The thermal conductivity of the conductive member is not particularly limited. The inventors have conducted research and confirmed that there is almost no change in the resonant frequency between copper, which has a thermal conductivity of 394 W / m K, and tungsten, which has a thermal conductivity of 174.3 W / m K.

[0034] [resin] (Resin composition) The resin is not particularly limited in type as long as it can contain the conductive material. It may be a thermosetting resin or a thermoplastic resin, but a thermosetting resin is preferred because the electromagnetic wave shielding sheet may be exposed to high temperatures depending on its intended use. Examples of thermosetting resins include thermosetting resins and photocurable resins. Examples of thermosetting resins include thermosetting acrylic resins, unsaturated polyester resins, epoxy resins, melamine resins, phenolic resins, silicone resins, polyimide resins, and urethane resins. Examples of photocurable resins include photocurable epoxy resins, photocurable polyesters, photocurable vinyl compounds, photocurable epoxy (meth)acrylates, and photocurable urethane (meth)acrylates. Among these, unsaturated polyester resins, photocurable polyesters, epoxy resins, and photocurable epoxy resins are preferred, with epoxy resins and photocurable epoxy resins being particularly preferred from the viewpoint of heat resistance. These resins may be used alone or in combination of two or more types in any desired type and ratio.

[0035] The resin content in the sheet is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 60% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, even more preferably 95% by weight or more, and particularly preferably 97% by weight or more, and is usually 99.99% by weight or less, preferably 99.90% by weight or less, more preferably 99.5% by weight or less, and even more preferably 99.0% by weight or less.

[0036] The conductive member may be completely embedded in the resin, or may not be completely embedded (only partially embedded), i.e., part of the conductive member may be exposed to the outside air. For example, in Example 1 described later, a sheet is produced in which the conductive member is completely embedded in the resin, and then the surface of the sheet is ground to expose part of the conductive material.

[0037] (Resin characteristics) Refractive index The refractive index of the resin is not particularly limited, but from the viewpoint of improving electromagnetic wave shielding properties, it is usually 1.35 or more and 1.76 or less, and preferably 1.55 or more and 1.61 or less, which is the refractive index of an epoxy resin. The refractive index can be measured by a known method.

[0038] Sheet (Seat configuration) The shape of the electromagnetic wave shielding sheet is not particularly limited as long as it is a sheet, and can be appropriately changed depending on the location where the sheet is to be installed. The sheet may be a single-layer sheet or a laminated sheet. When a laminated sheet is used, it may be a mode in which a plurality of sheets of the present embodiment are laminated, or a mode in which other sheets are laminated to impart various functions. The thickness of the sheet is not particularly limited, and from the viewpoint of the recent trend toward smaller, lighter, and thinner electronic devices such as mobile phones, smartphones, and tablets, it is usually 10 μm or more, preferably 20 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more, and is usually 10 mm or less, preferably 5 mm or less, more preferably 3 mm or less, and even more preferably 1.5 mm or less. The shape of the sheet is flat, but it may have an uneven shape or be partially curved within a range that can be considered approximately flat. Furthermore, the shape of the sheet observed from the surface may be circular or polygonal, such as triangular or rectangular.

[0039] The number of conductive members in the sheet is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding, it is usually 5 pieces / cm 2 More than 10 pieces / cm 2 It is preferable that the number of particles is 25 or more per cm. 2 More preferably, it is 100 particles / cm or more. 2 More preferably, it is 570 particles / cm or more. 2 Less than 400 cells / cm 2 Preferably, the number is 300 or less per cm 2 More preferably, it is 210 particles / cm or less. 2 It is even more preferable that: The number of the conductive members can be measured by internal observation using CT-X-rays.

[0040] The manner in which the conductive members are contained in the sheet is not particularly limited, and the conductive members may be arranged in any number at any position, or multiple conductive members may be arranged at equal intervals in the sheet surface direction.

[0041] The sheet may contain materials (other materials) other than the above-mentioned conductive members and resins, such as inorganic fillers other than conductive members. For example, the addition of inorganic fillers can adjust the linear expansion coefficient of the sheet, making it easier to prevent the sheet from warping, sagging, undulating, etc. The content of inorganic fillers other than the conductive material in the sheet is not particularly limited, and may be arbitrarily contained within a range in which the effects of this embodiment can be obtained.

[0042] (Sheet characteristics) Electromagnetic wave shielding In the present disclosure, the electromagnetic wave shielding property is evaluated by evaluating the power transmittance T(ω) using the following method. This evaluation method is based on the terahertz time-domain spectroscopy used in the transmittance measurement experiment. A schematic diagram of the experimental setup is shown in Figure 4. First, the light from the femtosecond laser is split into pump light and probe light by a beam splitter. The pump light acts as the light that excites the terahertz wave. The probe light synchronizes the timing of measuring the terahertz wave. By moving the delay stage, the optical path length of this probe light is changed, and the detection timing is shifted. The electric field E after the terahertz wave passes through the sample is sam (t) and the electric field E after passing through air without a sample ref (t) and are used to derive the complex refractive index, complex permittivity, permeability, power spectrum, etc. The transmittance is calculated from the data obtained from the above measurements by Fourier transform. sam (t), E ref (t) and E sam (ω), Eref (ω). Using these, the power transmittance T(ω) is expressed by the following formula (A).

[0043]

number

[0044] The transmittance can be measured using a terahertz spectroscopic system (for example, TAS7500TSH manufactured by Advantest Corporation).

[0045] The shielding performance L (dB) can be calculated from the power transmittance T (ω) using the following formula (B). L=10×Log 10 (T(ω) / 100) (B) The shielding performance L is not particularly limited, but is usually -2 dB or less, preferably -5 dB or less, and more preferably -10 dB or less. From the viewpoint of preventing malfunction of electronic devices such as computers, it is preferably -20 dB or less, more preferably -30 dB or less, even more preferably -40 dB or less, particularly preferably -60 dB or less, and most particularly preferably -80 dB or less. Although there is no need to set a lower limit, it is usually -90 dB or more. The power transmittance T(ω) of electromagnetic waves is expressed as -20 dB (shielding factor: 90%) when the electromagnetic waves are reduced to 1 / 10, -40 dB (shielding factor: 99%) when they are reduced to 1 / 100, -60 dB (shielding factor: 99.9%) when they are reduced to 1 / 1000, and -80 dB (shielding factor: 99.99%) when they are reduced to 1 / 10,000.

[0046] <Method of manufacturing resin molded body> Hereinafter, various embodiments relating to the manufacturing method of a resin molded product will be described, but the manufacturing method of the resin molded product described above is not limited to these manufacturing methods. In addition, manufacturing conditions that can be mutually applied in each embodiment can be mutually applied. In addition, the conditions for the resin molded product described above can be applied to the conditions for the manufacturing method described below to the extent applicable.

[0047] <First manufacturing method> A first manufacturing method of an electromagnetic wave shield according to another embodiment of the present disclosure (also simply referred to as a "first manufacturing method" in the description of this embodiment) is a manufacturing method of a resin molded product including a resin and a conductive member having a coil shape with a central axis, and at least a flat surface on one side, the manufacturing method including: a pocket resin member fabrication step of fabricating a resin member having a pocket and at least a flat surface on a portion thereof; a conductive member placement step of orienting and placing the conductive member in the pocket; and a pocket resin curing step of pouring a resin-containing composition into the pocket in which the conductive member is disposed and then curing the composition; and In the method for producing a resin molded article, the average angle formed between the plane and the central axis is 50° or more.

[0048] As described above in the description of the resin molded body, the shape of the resin molded body is preferably a sheet shape. In this case, a method for producing a resin molded body including a resin and a conductive member having a coil shape with a central axis, a pocket resin sheet manufacturing step of manufacturing a resin sheet having a pocket; a conductive member placement step of orienting and placing the conductive member in the pocket; and a pocket resin curing step of pouring a resin-containing composition into the pocket in which the conductive member is disposed and then curing the composition; and This can be expressed as a method for producing a resin molded article in which the average angle formed between the plane of the sheet and the central axis is 50° or more.

[0049] The first manufacturing method includes the resin sheet manufacturing step, the conductive member arranging step, and the pocket resin curing step, but may also include other steps. An example of the first manufacturing method including these other steps is shown below.

[0050] [Resin composition preparation process] The first manufacturing method may include a resin composition preparation step of preparing a resin composition by dissolving the above-mentioned resin and other materials in a solvent and mixing them. The mixing method is not particularly limited, and any known method can be applied. The type of solvent is not particularly limited as long as it can dissolve the resins and other materials described above. However, if molding is possible without using a solvent, it is not necessary to use a solvent. A curing agent may be added depending on the type of resin used, and known curing agents may be used appropriately depending on the resin. The content of the curing agent in the composition may be, for example, 0.05 to 15% by weight. Furthermore, a polymerization initiator may be added depending on the type of resin used. For example, as the thermal polymerization initiator, a thermal radical generator such as a peroxide, e.g., benzoyl peroxide, can be used. As the photopolymerization initiator, a photoradical generator, a photocation generator, a photoanion generator, or the like can be used.

[0051] [Pocket resin sheet manufacturing process] The first manufacturing method includes a pocket resin member fabrication step for fabricating a resin member having pockets and at least a partially flat surface (particularly a resin sheet having pockets). The method for fabricating a resin member having pockets and at least a partially flat surface is not particularly limited, and examples thereof include a method in which the resin composition obtained in the resin composition fabrication step is poured into a mold capable of forming pockets, and cured and molded by heat, ultraviolet light, or other light. Another example includes a method in which the resin composition is cured by a known method to mold a resin member having no pockets and at least a partially flat surface, and then laser processing is used to form pockets. Pressure may or may not be applied during molding, but if pressure is applied, press molding may be used, for example. The size of the pocket is set depending on the manner in which the final component will be used, since it greatly affects the angle between the central axis of the conductive member and the direction of the plane of at least a portion of the resin component (in the case of a sheet-shaped resin molded body, the direction of the sheet plane). For example, if it is desired to make the angle between the central axis of the conductive member and the direction of the plane of at least a portion of the resin component approximately 90°, the size of the pocket and the size of the conductive member (the shape of the cross section perpendicular to the central axis) should be approximately the same. The pockets may or may not extend through the member. Parameters such as the number of pockets and the thickness of the member can be appropriately set based on the explanation of each parameter in the configuration of the resin molded body described above.

[0052] [Conductive material placement process] First production method The method includes a conductive member arranging step of orienting and arranging conductive members in the pockets of the member obtained in the pocket resin sheet manufacturing step. As shown in FIG. 5, one method of orienting conductive members is to arrange conductive members 12 at a desired angle in pockets 13 of a pocket resin member (resin sheet in the drawing) 10 made of a cured resin composition 11 (also simply referred to as "resin 11"). In this case, if the pocket penetrates the member, an adhesive sheet may be placed under the member and adhered to the adhesive member so that the conductive members in the pockets are held at a desired angle, thereby orienting the conductive members. Sheet The pocket may be removed from the resin member after the pocket resin hardening step described below. In the above orientation, the resin member is arranged so that the average angle formed between the central axis and a plane that at least a part of the resin member has is 50° or more.

[0053] [Pocket resin hardening process] First production method The method includes a pocket resin curing step of pouring a resin-containing composition into the pocket in which the conductive member is placed in the conductive member placement step, and then curing the composition. The resin-containing composition to be poured is preferably the same as the resin prepared in the resin composition preparation step. The method for curing the composition is not particularly limited and can be changed appropriately depending on the type of resin, and examples thereof include a method of curing using heat, light such as ultraviolet light, etc. Furthermore, when the resin used is a thermoplastic resin and the composition is prepared in a melted state by applying heat, curing may be performed by leaving it to stand or by a cooling treatment, etc.

[0054] <Second manufacturing method> A second method for producing a resin molded body according to another embodiment of the present disclosure (also simply referred to as a "second production method" in the description of this embodiment) is a method for producing a resin molded body including a resin and a conductive member having a coil shape with a central axis, and having a flat surface on at least a portion thereof, a C-shaped conductive material-containing resin sheet production step of producing a plurality of resin sheets each having the resin, a C-shaped conductive material, and a columnar conductive material connected to an end of the C-shape; a lamination step of laminating a plurality of resin sheets so that an end of the C-shaped conductive material on one sheet and a column-shaped conductive material on the other sheet are in contact with each other in the central axis direction; The method for producing a resin molded article includes the steps of:

[0055] As described above in the description of the resin molded body, the shape of the resin molded body is preferably a sheet shape. In this case, a method for producing a resin molded body including a resin and a conductive member having a coil shape with a central axis, a C-shaped conductive material-containing resin sheet production step of producing a plurality of resin sheets each having the resin, a C-shaped conductive material, and a columnar conductive material connected to an end of the C-shape; a lamination step of laminating a plurality of resin sheets so that an end of the C-shaped conductive material on one sheet and a column-shaped conductive material on the other sheet are in contact with each other in the central axis direction; The method can be expressed as a method for producing a resin molded article, which includes the steps of:

[0056] The second manufacturing method includes the above-mentioned C-shaped conductive material-containing resin sheet manufacturing step and lamination step, but may further include other steps. An example of the second manufacturing method including these other steps will be described below.

[0057] [Resin composition preparation process] The second manufacturing method may include a resin composition preparation step of preparing a resin composition by dissolving the above-mentioned resin and other materials in a solvent and mixing them together. The conditions for the resin composition preparation step in the first manufacturing method can be applied to this step in the same way.

[0058] [C-shaped conductive material-containing resin sheet manufacturing process] The second manufacturing method includes a C-shaped conductive material-containing resin sheet manufacturing step for manufacturing a plurality of resin sheets each containing a resin, a C-shaped conductive material, and a columnar conductive material connected to the end of the C-shape. The method for manufacturing such a resin sheet is not particularly limited, but examples include a method in which a mold is prepared in which the C-shaped conductive material and the columnar conductive material are arranged, the resin composition obtained in the resin composition manufacturing step described above is poured into the mold, and the resin is cured to obtain a C-shaped conductive material-containing resin sheet 20 as shown in FIG. 6, which includes a cured resin composition 21 (also simply referred to as "resin 21"), a C-shaped conductive material 22, and a columnar conductive material 23. Examples of methods for curing the resin include a method using heat or light such as ultraviolet light. Alternatively, methods commonly used in the manufacture of printed wiring boards can be used. Specifically, after preparing a resin sheet by curing the resin composition, holes (vias) are drilled or lasered at the locations where the columnar conductive material will be placed, and a conductive material foil is formed on one side of the sheet. A photosensitive resist is then coated or laminated in a pattern that leaves the conductive material foil in a C-shape after etching, followed by etching to laminate the C-shaped conductive material onto the resin sheet. In addition to the method using the photosensitive resist described above, a method of laminating a C-shaped conductive material onto a resin sheet using etching can also be performed by printing an etching resist pattern. A method of subsequently pouring a conductive material paste into the holes and curing it to form a columnar conductive material, thereby obtaining a C-shaped conductive material-containing resin sheet, is also possible. Note that if air remains in the columnar-shaped areas, the volume resistivity increases and there is a risk of expansion, explosion, and destruction at the reflow temperature for mounting semiconductor components. Therefore, it is preferable that no air remains in the columnar-shaped areas. The parameters of the C-shaped conductive material and the columnar conductive material can be appropriately set based on the explanation of each parameter in the configuration of the resin molded body described above. In the embodiment using the C-shaped conductive material, the average angle formed by the plane of the sheet and the central axis is also subject to the above-mentioned average angle conditions.

[0059] [Lamination process] The second manufacturing method includes a lamination step of laminating a plurality of resin sheets, among the plurality of sheets produced in the C-shaped conductive material-containing resin sheet production step, so that an end of the C-shaped conductive material in one sheet contacts a columnar conductive material in another sheet in the central axis direction. The lamination method is, for example, as shown in Fig. 7, so that an end of the C-shaped conductive material in one sheet contacts a columnar conductive material in the other sheet in the central axis direction.

[0060] <Third manufacturing method> A third manufacturing method of an electromagnetic wave shield according to another embodiment of the present disclosure (also simply referred to as a "third manufacturing method" in the description of this embodiment) is a manufacturing method of a resin molded product including a resin and a conductive member having a coil shape with a central axis, and having a flat surface on at least a portion thereof, a conductive member-containing resin composition preparation step of preparing a resin composition containing the resin and a composition containing the conductive member; an orientation step of orienting the conductive member so that the angle between the planar direction (when the resin molded body is in a sheet shape, the planar direction of the sheet) and the central axis is 50° or more; a curing step of curing the conductive member-containing resin composition while maintaining the orientation of the conductive members; The method for producing a resin molded article includes the steps of:

[0061] As described above in the description of the resin molded body, the shape of the resin molded body is preferably a sheet shape. In this case, a method for producing a resin molded body including a resin and a conductive member having a coil shape with a central axis, a conductive member-containing resin composition preparation step of preparing a resin composition containing the resin and a composition containing the conductive member; an orientation step of orienting the conductive member so that the average angle between the planar direction of the sheet and the central axis is 50° or more; a curing step of curing the conductive member-containing resin composition while maintaining the orientation of the conductive members; The method can be expressed as a method for producing a resin molded article, which includes the steps of:

[0062] The third production method includes the conductive member-containing resin composition preparation step, the orientation step, and the curing step, and may further include other steps. An example of the third production method including these other steps is shown below.

[0063] [Magnetic material plating process] One method for orienting the conductive member in the orientation step described below is to orient the conductive member while applying a magnetic field. To achieve orientation using this method, the conductive member must be magnetic. Therefore, the third manufacturing method may include a magnetic material plating step in which the surface of the conductive member is plated with a magnetic material. Examples of magnetic materials include iron, cobalt, nickel, and gadolinium. The plating method is not particularly limited, and known methods can be used. The plating thickness can be set arbitrarily within the range in which the effects of the present invention are obtained, and may be, for example, 1 μm or more and 10 μm or less, 1 μm or more and 8 μm or less, 1 μm or more and 5 μm or less, 1 μm or more and 5 μm or less, or 2 μm or more and 4 μm or less. If the original conductive member contains a magnetic material, the conductive member can be oriented by applying a magnetic field without carrying out the magnetic material plating step.

[0064] [Conductive material-containing resin composition preparation process] The third manufacturing method has a step of preparing a resin composition containing a conductive material, which prepares a resin composition containing a resin and a composition containing a conductive material. When a magnetic field is used for orientation in the orientation step described below, the conductive material obtained in the magnetic material plating step may be used as the conductive material. The method of manufacturing the composition is not particularly limited, and may be any method, such as dissolving the resin, conductive material, or other material in a solvent. Addition The mixing method is not particularly limited, and known methods can be applied. The conditions for the resin composition preparation step in the first production method can be similarly applied to the suitability of using a solvent, and the type and content of the solvent.

[0065] [Orientation process] The third manufacturing method includes an orientation step of orienting the conductive member so that the angle between the planar direction (the planar direction of the sheet if the resin molded body is in a sheet shape) and the central axis is 50° or more. The method for orienting the conductive member is not particularly limited; for example, if the conductive member contains a magnetic material, or if the conductive member has been made magnetic in the magnetic material plating step, the conductive member can be oriented by applying a magnetic field. The method for generating the magnetic field is not particularly limited, and known methods can be applied. The conductive member can be oriented at a desired angle by controlling the direction and strength of the applied magnetic field.

[0066] [Curing process] The third manufacturing method includes a curing step of curing the conductive member-containing resin composition while maintaining the orientation of the conductive members. The curing method is not particularly limited, and examples thereof include methods using heat, light such as ultraviolet light, etc.

[0067] <Other manufacturing methods> As a method other than the above-described first to third manufacturing methods, for example, a method for manufacturing a resin molded body including a resin and a conductive member having a coil shape with a central axis and having a flat surface on at least a part thereof, a conductive member orienting step of orienting the conductive member so that the angle between the planar direction (when the resin molded body is in a sheet shape, the planar direction of the sheet) and the central axis is 50° or more; an orientation-maintaining resin pouring step of pouring a resin composition containing the resin while maintaining the orientation of the conductive member; and a curing step of curing the resin composition while maintaining the orientation of the conductive member; The method for producing a resin molded article includes the steps of:

[0068] As described above in the description of the resin molded body, the shape of the resin molded body is preferably a sheet shape. In this case, a method for producing a resin molded body including a resin and a conductive member having a coil shape with a central axis, a conductive member orienting step of orienting the conductive member so that the angle between the planar direction of the sheet and the central axis is 50° or more; an orientation-maintaining resin pouring step of pouring a resin composition containing the resin while maintaining the orientation of the conductive member; and a curing step of curing the resin composition while maintaining the orientation of the conductive member; The method can be expressed as a method for producing a resin molded article, which includes the steps of:

[0069] The method of orientation in the conductive member orienting step is not particularly limited, and examples thereof include a method in which an adhesive sheet is prepared and the conductive member is attached to the adhesive sheet at a specific angle. The pouring method in the above-mentioned orientation-maintaining resin pouring step is not particularly limited, but it is preferable to pour the resin at a desired pouring speed so that the orientation of the conductive member can be maintained. The curing method in the curing step is not particularly limited, and in the case of a thermosetting resin, a method of curing by treatment with heat, light, or the like can be mentioned.

[0070] Another method for alignment in the conductive member alignment step is to arrange conductive members 32 using a support A31, as shown in Fig. 8(a). The material of the support A31 is not particularly limited, and may be a conductive material, an inorganic material, an organic material, or the like. Thereafter, for example, a support B33 coated with resin composition S is brought into contact with the ends of all of the coils, and the resin composition S is cured. As shown in Fig. 8(b), the conductive members 32 are fixed with a cured product 34 of the resin composition S. Thereafter, the conductive members 32 are removed from the support A31, and while maintaining the orientation of the conductive members 32, a resin composition T containing a resin is poured in (orientation-retaining resin pouring step), and the resin composition T is cured (curing step), to obtain a resin molded product having a cured product 35 of the resin composition T and the conductive members 32, as shown in Fig. 8(c). Note that the support B33 may be removed in the end. The resin composition S for fixing the ends of all of the coils and the resin composition T poured in the orientation-retaining resin pouring process may be the same material or different materials, but from the viewpoint of stability of characteristics, it is preferable that they are the same.

[0071] <Second resin molded body> The second resin molded body will be described in detail below. <Configuration and characteristics of electromagnetic wave shielding sheet> A second resin molded body (also simply referred to as "resin molded body") according to an embodiment of the present disclosure is a resin molded body that includes a resin and a conductive coil (also simply referred to as "coil"), and in which the conductive member that constitutes the conductive coil is spiral. "The conductive member that constitutes the conductive coil is spiral" can also be expressed as the spiral conductive coil further forming a spiral, or the central axis of the spiral conductive coil being formed to form a spiral, or the wire that forms the conductive coil is spiral.

[0072] The inventors focused on a coil shape with a central axis as a structure that can obtain strong absorption of electromagnetic waves in the terahertz region. The coil-shaped material can control polarization. When linearly polarized incident electromagnetic waves are incident on the coil-shaped material, the polarization becomes elliptically polarized and is emitted. In this way, the coil-shaped material can be used to control polarization. In this embodiment, we focused on the magnitude of the coil-shaped electromagnetic wave absorption, rather than polarization control. Furthermore, the inventors have noticed that one turn of the coil shape can be regarded as an LC resonant circuit. In this case, when the transmittance of the material of the coil shape is examined, the effect of absorbing electromagnetic waves is obtained by LC resonance, with the gap of the coil shape as capacitance C and the coil shape itself as inductance L. Then, by increasing the number of turns of the coil shape, the electromagnetic waves Absorption of It was thought that this could increase the effect of The effect of absorbing electromagnetic waves by the LC resonance is also greatly affected by the angle between the central axis of the coil and the electromagnetic waves. Specifically, when the angle is 90°, the effect of absorbing electromagnetic waves is small, whereas when the angle is 0°, the effect of absorbing electromagnetic waves is large. The present inventors have focused on the above point and have developed a method for manufacturing a coil-shaped conductive filler containing a conductive coil, the conductive coil being a spiral conductive member. The inventors have found that by using a conductive coil, it is possible to produce a member (particularly a sheet member) having excellent electromagnetic wave shielding properties, and have thus completed the present invention.

[0073] The shape of the resin molded body is not particularly limited as long as it has a flat surface at least in part, and the position of the flat surface is not particularly limited, but it is preferable to form the resin molded body so that the normal direction of the flat surface is the incident direction of electromagnetic waves from outside, and further, when the resin molded body is to be placed on another member for use, it is preferable to form the resin molded body so that the flat surface serves as the installation surface for the other member. Specific shapes of the resin molded body include, for example, a sheet shape, a spherical shape having a flat surface on one side, a cylindrical shape or a polygonal prism shape having a flat surface on one side, etc., but from the viewpoint of ease of handling, a sheet shape is preferred.

[0074] The applications of the above molded article are not particularly limited, and examples thereof include electromagnetic wave shielding. Hereinafter, a sheet-shaped resin molded article, particularly an electromagnetic wave shielding sheet, will be specifically described. Note that the plane of the sheet in the following description corresponds to the plane that at least a portion of the resin molded article in this embodiment has. Furthermore, to the extent applicable, the conditions for the following embodiments can also be applied to the conditions for embodiments other than the sheet-shaped article.

[0075] In this embodiment, the conductive coil described above is also referred to as a "double coil," and a normal conductive coil that does not have the above-described spiral shape is referred to as a "single coil." As shown in FIGS. 20 and 21 , the conductive member constituting the conductive coil in the double coil is further spiral-shaped. FIG. 20 is a schematic diagram of one embodiment of the coil, and FIG. 21 is a scanning electron microscope image of the conductive coil. Hereinafter, in the double coil, the spiral constituting the same spiral shape as that of the single coil will be referred to as the "major spiral," and the spirals formed on the lines constituting the major spiral will be referred to as the "minor spiral." In FIG. 20 , G represents the central axis of the major spiral, and H represents the central axis of the minor spiral. In the electromagnetic wave shielding sheet according to this embodiment, when electromagnetic waves pass through the interior of the major spiral, the effect of absorbing the electromagnetic waves is exerted by the LC resonance derived from the major spiral. Furthermore, when electromagnetic waves pass through the interior of the minor spiral, the effect of absorbing the electromagnetic waves is also exerted by the LC resonance derived from the minor spiral. In the electromagnetic wave shielding sheet according to this embodiment, by using a coil having such a structure, sufficient shielding properties can be ensured even against electromagnetic waves in the high-frequency band.

[0076] As will be explained later in the sheet manufacturing method, an electromagnetic wave shielding sheet containing a double coil can be manufactured, for example, by preparing a composition containing a double coil and a resin and curing it. Regardless of whether the filler is single coil or double coil, when a sheet is generally produced using a coil-shaped filler in a manner similar to the double coil production method described above, that is, by curing a composition containing a coil and a resin, if the time from production to curing of the composition is short, a sheet in which multiple coils are oriented at an arbitrary inclination is obtained, whereas if the time from production to curing of the composition is long, the coils have a greater specific gravity than the resin, and therefore the sheet is produced in which the coils are lying down, that is, in which the angle between the central axis of the coil's large spiral and the planar direction of the sheet is close to 0° and a large proportion of the coils are lying down.

[0077] Here, when the time from production to curing of the composition is short (in the case of a sheet in which multiple coils are oriented at arbitrary angles), if a single coil is used as the coil, coils of all angles will be present with roughly equal probability, and therefore a significant electromagnetic wave shielding effect cannot be obtained.On the other hand, if a double coil is used as the coil, a significant electromagnetic wave shielding effect can be obtained because there is a "small spiral" portion that a single coil does not have and because the central axis itself is spiral, which can generate electromagnetic wave absorption by LC resonance against electromagnetic waves from various directions. Furthermore, when the time from preparation to curing of the composition is long (i.e., when the sheet contains a large proportion of coils with an angle between the central axis of the coil and the sheet plane direction close to 0°), using a single coil results in an almost complete electromagnetic shielding effect, since the angle between the central axis of the coil and the direction of the electromagnetic waves approaches 90° (e.g., 60 to 90°). On the other hand, when a double coil such as that shown in Figure 21 is used as the coil, the direction of the central axis of the double coil's major spiral is approximately the same as the sheet plane, as in the case of a single coil. However, the central axis of the minor spiral moves from approximately 0° to approximately 90° relative to the sheet plane direction, and then spirals from approximately 90° to approximately 0° (one turn is approximately 0° → approximately 90° → approximately 0° → approximately 90° → approximately 0°). Thus, a portion of the central axis of the minor spiral forms an angle close to 90° with the sheet plane, at which electromagnetic wave absorption due to LC resonance is maximized. Furthermore, this angle at which electromagnetic wave absorption due to LC resonance is maximized exists for the number of turns of the minor spiral. Therefore, when a double coil is used, a large electromagnetic wave shielding effect can be obtained even when a long time passes from the preparation of the composition to its curing.

[0078] When a general metal coil is used, it is preferable that the metal coil have a metamaterial structure from the viewpoint of improving various parameters of electromagnetic wave shielding. In this embodiment, the metamaterial structure refers to a configuration in which metal coils are aligned and arranged in a resin, and more specifically, a configuration in which metal coils are arranged at periodic intervals in a resin. In the case of a single coil, the metamaterial structure is formed only when each single coil is aligned and arranged. On the other hand, in the case of a double coil, a structure in which small spirals are necessarily aligned and arranged in the double coil exists. In other words, the double coil itself can be considered to be a material having a single metamaterial structure. Therefore, the double coil is not limited to a configuration in which the coils are aligned like a single coil, and the effects of a metamaterial structure can be obtained in any configuration.

[0079] [Conductive coil] (Conductive coil configuration) The conductive coil (double coil) is not particularly limited as long as the conductive member constituting the conductive coil is spiral, as shown in Figures 20 and 21. The double coil can be produced by a known method, and a commercially available product may also be used. The central axis of the double-coil large helix need not necessarily be a straight line, but may be one that can approximate a straight line. In cases where the central axis is one that can approximate a straight line, that approximate line becomes the central axis.

[0080] The cross-sectional shape of the wire that constitutes the spiral shape is not particularly limited and may be, for example, circular or polygonal such as triangular or rectangular, but is preferably circular from the standpoint of ease of availability and ease of manufacture. Furthermore, as shown in Figure 22 (the structure of the small spiral is omitted), multiple double coils may or may not be connected. If they are connected, the central axes of the large spiral shapes do not have to be on the same axis. If the central axes of the large spiral shapes do not lie on the same axis, each part having a spiral shape is treated as a single double coil, and parameters for each double coil are calculated.

[0081] The type of material for the double coil is not particularly limited as long as it is conductive, and examples include carbon materials such as carbon, copper (Cu), aluminum (Al), iron (Fe), gold (Au), silver (Ag), platinum (Pt), magnesium (Mg), zinc (Zn), tungsten (W), titanium (Ti), nickel (Ni), or manganese (Mn), alloys consisting of combinations of these metal elements, or metal-containing compounds such as oxides, halides, or sulfides of these metal elements or alloys.Copper (Cu) or iron (Fe) are preferred, and tungsten (W) is particularly preferred, from the perspective that the durability of the resin sheet is good because their elastic modulus is suitable for coil processing, and when contained in a resin, they have good corrosion resistance and a small linear expansion coefficient.

[0082] The content of the double coil in the sheet is not particularly limited, but from the viewpoint of improving the electromagnetic wave shielding property, the content per volume of the sheet is usually 0.02 g / cm 3 or more, 0.05 g / cm 3 It is preferable that the concentration is 0.10 g / cm or more. 3 More preferably, it is 0.150 g / cm or more. 3 More preferably, it is 0.20 g / cm or more. 3 It is particularly preferable that the density is 5.00 g / cm or more, and usually 5.00 g / cm 3 Less than 4.50 g / cm 3 Preferably, it is less than 3.00 g / cm 3 More preferably, it is less than 2.00 g / cm 3 More preferably, it is less than 1.50 g / cm 3 It is particularly preferred that it is less than 10 ...

[0083] The electromagnetic wave shielding sheet of this embodiment uses a double coil, which has better electromagnetic wave shielding per coil than a single coil, so when trying to achieve the same level of electromagnetic wave shielding performance, the electromagnetic wave shielding sheet of this embodiment can use less conductive material than an electromagnetic wave shielding sheet manufactured using a single coil.Since conductive materials are usually more expensive per volume than resins, the electromagnetic wave shielding sheet of this embodiment has lower material costs than an electromagnetic wave shielding sheet manufactured using a single coil.

[0084] As shown in Figure 2 (the structure of the minor helix is ​​omitted), if the angle between the central axis of the major helix of the double coil and the plane of the sheet is θ, then from the viewpoint of ensuring sufficient electromagnetic wave shielding, θ is typically 50° or less, preferably 40° or less, more preferably 30° or less, even more preferably 20° or less, particularly preferably 10° or less, and most particularly preferably 5° or less, with 0° being theoretically the most preferable. The average angle is the average value of the angles between the central axis of the major helix obtained in each double coil present in the sheet and the plane of the sheet. The closer θ is to 0°, the closer the angle between the central axis of the minor coil and the plane of the sheet tends to be to 90°, thereby increasing the electromagnetic wave shielding effect. The above angle can be measured by internal observation using CT-X-ray.

[0085] When multiple double coils are used, since the double coils themselves have a metamaterial structure as described above, it is not particularly necessary to arrange each double coil in a metamaterial structure, but from the viewpoint of ensuring higher electromagnetic wave shielding properties, it is preferable that the arrangement of the double coils themselves has a metamaterial structure. In the case of a metamaterial structure, the arrangement is not particularly limited, and examples include an arrangement in which the coils are arranged to form a circle or a polygon such as a triangle or square. This arranged arrangement may be configured in one row or two or more rows.

[0086] Figure 23 shows an example in which two double coils with an angle θ of 90° are arranged side by side in a resin. The top view in Figure 23 shows the double coil observed from the direction of the central axis of the major helix of the double coil, and the bottom view shows the double coil observed from a direction 90° from the central axis. In Figure 23, l is the average outer diameter of the major helix, m is the average winding pitch of the major helix, n is the average length of the double coil in the direction of the central axis of the major helix, o is the average coil alignment pitch, p is the average outer diameter of the minor helix, q is the average winding pitch of the minor helix, and r is the average strand diameter. When multiple double coils are used, the average outer diameter l of the major helix is ​​calculated as the average value of the multiple double coils. In this embodiment, when "average" is used as a parameter of the double coil, the other parameters are also calculated in the same manner as the average outer diameter. All of these parameters can be measured by internal observation using CT-X-rays. The average coil alignment pitch is a parameter that is specified when conductive members are arranged at equal intervals, and the length of the intervals is the average coil alignment pitch. For example, when conductive coils are arranged in a planar direction, consider a square grid of lines formed on a sheet, consisting of multiple equally spaced vertical lines and multiple equally spaced horizontal lines, with the vertical and horizontal lines spaced the same. In this case, the spacing between the vertical lines (or horizontal lines) when each square contains one conductive coil is the average coil alignment pitch. Alternatively, conductive coils may be arranged at equal intervals of different lengths in multiple directions. For example, they may be arranged at equal intervals of length X vertically and length Y horizontally. In other words, the average coil alignment pitch may be determined by converting the square grid lines into rectangular grid lines, in which case the average value of X and Y is the average coil alignment pitch.

[0087] The average outer diameter 1 of the major helix (also simply referred to as "major helix outer diameter") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 10.5 μm or more, preferably 105 μm or more, more preferably 210 μm or more, and even more preferably 315 μm or more, and is usually 1470 μm or less, preferably 1365 μm or less, more preferably 1050 μm or less, and even more preferably 525 μm or less. Furthermore, when the angle between the central axis of the major helix and the sheet plane is perpendicular, the smaller the major helix outer diameter, the wider the electromagnetic wave frequency band that can be effectively shielded, and the more likely it is that the frequency band will shift to high frequencies above 100 GHz. When the angle is horizontal, a major helix outer diameter greater than the above lower limit increases the vertical length of the minor helix that can effectively shield, thereby improving shielding performance.

[0088] The mean winding pitch m of the major helix (also simply referred to as "major helix winding pitch") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually greater than 140 μm (greater than 140 μm), preferably 175 μm or more, more preferably 210 μm or more, and even more preferably 245 μm or more, and usually 560 μm or less, preferably 490 μm or less, more preferably 420 μm or less, and even more preferably 350 μm or less. Furthermore, when the angle between the central axis of the major helix and the sheet plane is perpendicular, the smaller the major helix winding pitch, the wider the electromagnetic wave frequency band that can be effectively shielded, and the more likely it is to shift to high frequency bands, particularly 100 GHz or higher. When the angle is horizontal, if the major helix winding pitch is greater than the above upper limit, the inclination of the minor helix that can effectively shield becomes greater, resulting in reduced shielding performance.

[0089] The average length n of the double coil (coil-shaped portion) along the central axis of the major helix (also simply referred to as "the length of the double coil along the central axis of the major helix") is typically 20 μm or more, preferably 100 μm or more, more preferably 500 μm or more, and even more preferably 1000 μm or more, from the viewpoint of ensuring sufficient electromagnetic wave shielding properties. It is also typically 10,000 μm or less, preferably 8,000 μm or less, more preferably 6,000 μm or less, and even more preferably 4,000 μm or less. Furthermore, when the angle between the central axis of the major helix and the sheet plane is perpendicular, the length of the double coil along the central axis of the major helix does not affect the frequency band of electromagnetic waves that can be effectively shielded, but the longer the length, the better the shielding performance. Furthermore, when the angle is horizontal, the length of the double coil along the central axis of the major helix does not affect the frequency band of electromagnetic waves that can be effectively shielded or the shielding performance.

[0090] The average coil alignment pitch o (also simply referred to as "coil alignment pitch") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 420 μm or more, preferably 500 μm or more, more preferably 600 μm or more, and even more preferably 700 μm or more, and is usually 4000 μm or less, preferably 3000 μm or less, more preferably 2000 μm or less, and even more preferably 1000 μm or less. Furthermore, when the angle between the central axis of the large spiral and the sheet plane is perpendicular, the larger the coil alignment pitch, the smaller the frequency band of electromagnetic waves that can be effectively shielded. Conversely, when the angle is horizontal, the larger the coil alignment pitch, the smaller the frequency band of electromagnetic waves that can be effectively shielded.

[0091] The average outer diameter p of the minor spirals (also simply referred to as "outer diameter of the minor spirals") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually greater than 3.5 μm (greater than 3.5 μm), preferably 35 μm or more, more preferably 70 μm or more, and more preferably 105 μm or more, and is usually 490 μm or less, preferably 455 μm or less, more preferably 350 μm or less, and even more preferably 175 μm or less. When the angle between the central axis of the major spiral and the sheet plane is perpendicular, the larger the outer diameter of the minor spiral, the smaller the frequency band of electromagnetic waves that can be effectively shielded. When the angle is horizontal, the larger the outer diameter of the minor spiral, the smaller the frequency band of electromagnetic waves that can be effectively shielded.

[0092] The average winding pitch q of the minor spiral (also simply referred to as "minor spiral winding pitch") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually greater than 20 μm (greater than 20 μm), preferably 25 μm or more, more preferably 30 μm or more, and even more preferably 35 μm or more, and is usually 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 70 μm or less. Furthermore, when the angle between the central axis of the major spiral and the sheet plane is perpendicular, the larger the minor spiral winding pitch, the smaller the electromagnetic wave frequency band that can be effectively shielded. Conversely, when the angle is horizontal, the larger the minor spiral winding pitch, the smaller the electromagnetic wave frequency band that can be effectively shielded.

[0093] The average strand diameter r (also simply referred to as "strand diameter") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually greater than 1 μm (larger than 1 μm), preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more, and is usually 140 μm or less, preferably 130 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. Furthermore, when the angle between the central axis of the large helix and the sheet plane is perpendicular, the larger the strand diameter, the wider the electromagnetic wave frequency band that can be effectively shielded, and when the angle is horizontal, the larger the strand diameter, the wider the electromagnetic wave frequency band that can be effectively shielded.

[0094] The average number of turns in the major helix (also simply referred to as "number of turns in the major helix") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties, it is usually 4 or more, preferably 5 or more, and more preferably 6 or more, and usually less than 14, preferably 11 or less, more preferably 10 or less, and even more preferably 8 or less. When the angle between the central axis of the major helix and the sheet plane direction is perpendicular, the fewer the number of turns in the major helix, the wider the frequency band of electromagnetic waves that can be effectively shielded, and the more likely that frequency band will be shifted to high frequencies of 100 GHz or higher. When the angle is horizontal, when the number of turns in the major helix is ​​less than the above lower limit, the inclination of the minor helix that can effectively shield becomes large, resulting in reduced shielding performance.

[0095] The average number of turns of the minor spiral (also simply referred to as "number of turns of the minor spiral") is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic shielding properties, it is usually 24 or more, preferably 36 or more, more preferably 63 or more, and even more preferably 108 or more, and is usually 942 or less, preferably 603 or less, more preferably 419 or less, and even more preferably 308 or less. The above range of the number of turns is a particularly preferred range when the angle between the central axis of the major spiral and the plane of the sheet is perpendicular.

[0096] (Double coil characteristics) Volume resistivity The volume resistivity of the double coil is not particularly limited, and is not particularly limited as long as it is a value that allows a small current to flow. The inventors have conducted an investigation and confirmed that there is almost no change in the resonance frequency between copper with a volume resistivity of 1.55 μΩcm (0°C) and tungsten with a volume resistivity of 4.9 μΩcm (0°C). flow An example of the value at which the volume resistivity of carbon (graphite) is 3352.8 μΩcm (20° C.).

[0097] Thermal conductivity There are no particular restrictions on the thermal conductivity of the double coil. The inventors conducted an investigation and confirmed that there was almost no change in the resonant frequency between copper, which has a thermal conductivity of 394 W / m K, and tungsten, which has a thermal conductivity of 174.3 W / m K.

[0098] [resin] (Resin composition) The resin is not particularly limited in type as long as it can contain the double coil. It may be a thermosetting resin or a thermoplastic resin, but a thermosetting resin is preferred because the electromagnetic wave shielding sheet may be exposed to high temperatures depending on its intended use. Examples of thermosetting resins include thermosetting resins and photocurable resins. Examples of thermosetting resins include thermosetting acrylic resins, unsaturated polyester resins, epoxy resins, melamine resins, phenolic resins, silicone resins, polyimide resins, and urethane resins. Examples of photocurable resins include photocurable epoxy resins, photocurable polyesters, photocurable vinyl compounds, photocurable epoxy (meth)acrylates, and photocurable urethane (meth)acrylates. Among these, epoxy resins and photocurable epoxy resins are preferred from the viewpoint of heat resistance. These resins may be used alone or in combination of two or more types in any desired type and ratio.

[0099] The resin content in the sheet is not particularly limited, but from the viewpoint of ensuring sufficient electromagnetic wave shielding properties and from the viewpoint of raw material costs, it is usually 60% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, even more preferably 95% by weight or more, and particularly preferably 97% by weight or more, and is usually 99.99% by weight or less, preferably 99.90% by weight or less, more preferably 99.5% by weight or less, and even more preferably 99.0% by weight or less.

[0100] (Resin characteristics) Refractive index The refractive index of the resin is not particularly limited, but from the viewpoint of improving the electromagnetic wave shielding property, it is usually 1.35 to 1.76, and preferably 1.55 to 1.61, which is the refractive index of an epoxy resin. The refractive index can be measured by a known method.

[0101] [Composition] Another embodiment of the present disclosure, a composition for a resin molded body (also simply referred to as a "composition for a resin molded body" in the description of this embodiment), is a composition for a resin molded body (particularly an electromagnetic wave shielding sheet) that includes a resin and a conductive coil, and the conductive member that constitutes the conductive coil is spiral-shaped. The resin and conductive coil (double coil) in this embodiment can be the resin and double coil in the above-described embodiment, and the configuration, characteristics, and uses of the resin molded body obtained using the composition of this embodiment can be the configuration, characteristics, and uses of the resin molded body described above or below. The composition may also contain other materials described below. Furthermore, the composition may contain a solvent or a polymerization initiator, and the type and content of the solvent and polymerization initiator can be determined according to the conditions described in the conductive coil-containing resin composition curing step in the first manufacturing method described below.

[0102] Sheet (Seat configuration) The shape of the electromagnetic wave shielding sheet is not particularly limited as long as it is a sheet, and can be appropriately changed depending on the location where the sheet is to be installed. The sheet may be a single-layer sheet or a laminated sheet. When a laminated sheet is used, it may be a mode in which a plurality of sheets of the present embodiment are laminated, or a mode in which other sheets are laminated to impart various functions. The thickness of the sheet is not particularly limited, and from the viewpoint of recent miniaturization, lightness, and thinning of electronic devices such as mobile phones, smartphones, tablets, etc., it is usually 10 μm or more, preferably 20 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more, and is usually 10 mm or less, preferably 5 mm or less, more preferably 3 mm or less, and even more preferably 1.5 mm or less. The shape of the sheet is flat, but it may have an uneven shape or be partially curved within a range that can be considered approximately flat. Furthermore, the shape of the sheet observed from the surface may be circular or polygonal, such as triangular or rectangular.

[0103] There is no particular limit to the number of double coils in the sheet, but from the viewpoint of ensuring sufficient electromagnetic wave shielding, it is usually set to 6 coils / cm with respect to the area in the planar direction of the sheet. 2 More than 11 pieces / cm 2 It is preferable that the number of particles is 25 or more per cm. 2 More preferably, it is 100 particles / cm or more. 2 More preferably, it is 700 particles / cm or more. 2 Less than 400 cells / cm 2 It is preferable that the number of particles is 280 or less per cm. 2 More preferably, it is 200 particles / cm or less. 2It is even more preferable that the following holds: When the angle between the central axis of the large spiral and the plane of the sheet is perpendicular, the greater the number of double coils, the smaller the distance between the coils, and therefore the wider the frequency band of electromagnetic waves that can be effectively shielded; similarly, when the angle is horizontal, the greater the number of double coils, the smaller the distance between the coils, and therefore the wider the frequency band of electromagnetic waves that can be effectively shielded. The number of double coils can be measured by internal observation using CT-X-rays.

[0104] The manner in which the double coil is contained in the sheet is not particularly limited, and the double coil may be arranged in any number at any position, or multiple double coils may be arranged at equal intervals in the sheet surface direction.

[0105] The sheet may contain materials (other materials) other than the double coil and resin, such as inorganic fillers other than the double coil. For example, the addition of an inorganic filler can adjust the linear expansion coefficient of the sheet, making it easier to prevent the sheet from warping, sagging, undulating, etc. The content of inorganic fillers other than the double coil in the sheet is not particularly limited, and may be arbitrarily contained within a range in which the effects of this embodiment can be obtained.

[0106] (Sheet characteristics) Electromagnetic wave shielding In the present disclosure, the electromagnetic wave shielding property is evaluated by evaluating the power transmittance T(ω) using the following method. This evaluation method is based on the terahertz time-domain spectroscopy used in the transmittance measurement experiment. A schematic diagram of the experimental setup is shown in Figure 4. First, the light from the femtosecond laser is split into pump light and probe light by a beam splitter. The pump light acts as the light that excites the terahertz wave. The probe light synchronizes the timing of measuring the terahertz wave. The optical path length of this probe light is changed by moving the delay stage, and the detection timing is adjusted. of The electric field E after the terahertz wave passes through the samplesam (t) and the electric field E after passing through air without a sample ref (t) is detected. These values ​​are used to derive the complex refractive index, complex permittivity, permeability, power spectrum, etc. The transmittance is calculated from the data obtained from the above measurements by Fourier transform. sam (t), E ref (t) and E sam (ω), Eref (ω). The power transmittance T(ω) is expressed by the following equation (A) using these.

[0107]

number

[0108] The transmittance can be measured using a terahertz spectroscopic system (for example, TAS7500TSH manufactured by Advantest Corporation).

[0109] The shielding performance L (dB) can be calculated from the power transmittance T (ω) using the following formula (B). L=10×Log 10 (T(ω) / 100) (B) The shielding performance L is not particularly limited, but is usually -2 dB or less, preferably -5 dB or less, and more preferably -10 dB or less. From the viewpoint of preventing malfunction of electronic devices such as computers, it is usually -20 dB or less, preferably -30 dB or less, preferably -40 dB or less, more preferably -60 dB or less, and even more preferably -80 dB or less. Although there is no need to set a lower limit, it is usually -90 dB or more. The power transmittance T(ω) of electromagnetic waves is expressed as -20 dB (shielding factor: 90%) when the electromagnetic waves are reduced to 1 / 10, -40 dB (shielding factor: 99%) when they are reduced to 1 / 100, -60 dB (shielding factor: 99.9%) when they are reduced to 1 / 1000, and -80 dB (shielding factor: 99.99%) when they are reduced to 1 / 10,000.

[0110] <Method of manufacturing resin molded body> Hereinafter, various embodiments relating to manufacturing methods of resin molded articles will be described, but the manufacturing methods of the resin molded articles described above are not limited to these manufacturing methods. As a method other than the first manufacturing method and the second manufacturing method described below, for example, the manufacturing method in Example 1 of Experiment 1 in the examples described below may be adopted. Furthermore, manufacturing conditions that can be mutually applied in each embodiment can be mutually applied. Furthermore, to the extent applicable, the conditions for the resin molded articles described above can be applied to the conditions for the manufacturing methods described below.

[0111] <First manufacturing method> A first method for producing a resin molded body according to another embodiment of the present disclosure (also simply referred to as a "first production method" in the description of this embodiment) is a method for producing a resin molded body including a resin and a conductive coil, a conductive coil-containing resin composition curing step of preparing a resin composition containing the resin and a composition containing the conductive coil, and then curing the composition; and The conductive member constituting the conductive coil is spiral. A method for manufacturing a resin molded body. The first manufacturing method includes the step of curing the conductive coil-containing resin composition, and may further include other steps. An example of the first manufacturing method is shown below.

[0112] [Conductive coil-containing resin composition curing step] The first manufacturing method includes a step of preparing a resin composition containing a resin and a composition containing the conductive coil (double coil), and then curing the composition. The method for preparing the composition is not particularly limited, and the resin, double coil, and other materials described above are dissolved in a solvent. Addition The mixing method is not particularly limited, and known methods can be applied. The type of solvent is not particularly limited as long as it can dissolve the resins and other materials described above. However, if molding is possible without using a solvent, it is not necessary to use a solvent. A curing agent may be added depending on the type of resin used, and known curing agents may be used appropriately depending on the resin. The content of the curing agent in the composition may be, for example, 0.05 to 15% by weight. Furthermore, a polymerization initiator may be added depending on the type of resin used. For example, as the thermal polymerization initiator, a thermal radical generator such as a peroxide, e.g., benzoyl peroxide, can be used. As the photopolymerization initiator, a photoradical generator, a photocation generator, a photoanion generator, or the like can be used. The method for curing the composition is not particularly limited, and examples thereof include methods that utilize heat or light such as ultraviolet light.

[0113] <Second manufacturing method> A second method for producing a resin molded body according to another embodiment of the present disclosure (also simply referred to as a "second production method" in the description of this embodiment) is a method for producing a resin molded body including a resin and a conductive coil, a pocket resin sheet manufacturing step of manufacturing a resin sheet having a pocket; a conductive coil placement step of placing the conductive coil in the pocket in an oriented manner; and a pocket resin curing step of pouring a resin-containing composition into the pocket in which the conductive coil is disposed and then curing the composition; and In the method for producing a resin molded article, the conductive member that constitutes the conductive coil is spiral.

[0114] The second manufacturing method includes the above-mentioned resin sheet manufacturing step, conductive coil arrangement step, and pocket resin hardening step, but may further include other steps. 2 An example of the manufacturing method is shown below.

[0115] [Resin composition preparation process] The second manufacturing method may include a resin composition preparation step of preparing a resin composition by dissolving the above-mentioned resin and other materials in a solvent and mixing them. The mixing method is not particularly limited, and any known method can be applied. The conditions for the resin composition preparation step in the first production method can be similarly applied to the suitability of using a solvent, and the type and content of the solvent.

[0116] [Pocket resin sheet manufacturing process] The second manufacturing method includes a pocket resin sheet manufacturing step of manufacturing a resin sheet having pockets. The method of manufacturing a resin sheet having pockets is not particularly limited, and examples thereof include a method of pouring the resin composition obtained in the resin composition manufacturing step described above into a mold capable of forming pockets, and curing and molding the resin composition with heat or light such as ultraviolet light. Another example is a method of curing the resin composition using a known method to mold a resin sheet without pockets, and then forming pockets by laser processing. Pressure may or may not be applied during molding, but if pressure is applied, press molding may be used, for example. The size of the pocket has a significant effect on the inclination of the conductive coil (double coil), so the size of the pocket is set depending on the intended use of the final sheet. For example, if you want the angle between the central axis of the large spiral of the double coil and the sheet plane direction to be approximately 90°, you can simply make the size of the pocket and the size of the double coil (the cross-sectional shape perpendicular to the central axis) approximately the same. The pockets may or may not extend through the sheet. Parameters such as the number of pockets and the thickness of the sheet can be appropriately set based on the explanation of each parameter in the configuration of the resin molded body described above.

[0117] [Conductive coil placement process] The second manufacturing process includes a conductive coil arrangement step in which a double coil is arranged in a pocket of the sheet obtained in the pocket resin sheet preparation step. The double coil may be oriented, but need not be. One method for orienting the double coil is to arrange a conductive coil (double coil) in place of the conductive member 12 in the conductive member arrangement step so that the double coil is at a desired angle in the pocket 13 of the pocket resin sheet 10 made of a cured resin composition 11 (also simply referred to as "resin 11"). In this case, if the pocket penetrates the sheet, an adhesive sheet may be placed under the sheet and adhered to the adhesive sheet so that the double coil in the pocket is held at the desired angle, thereby orienting the double coil. The adhesive sheet may be removed from the resin sheet after the pocket resin curing step described below.

[0118] [Pocket resin hardening process] The second manufacturing process includes a pocket resin curing process in which a resin-containing composition is poured into the pocket in which the double coil is placed in the conductive coil placement process, and then the composition is cured. The resin-containing composition to be poured is preferably the same as the resin prepared in the resin composition preparation process. The method for curing the composition is not particularly limited and can be changed appropriately depending on the type of resin, and examples thereof include a method of curing using heat, light such as ultraviolet light, etc. Furthermore, when the resin used is a thermoplastic resin and the composition is prepared in a melted state by applying heat, curing may be performed by leaving it to stand or by cooling.

[0119] <Applications of resin molded products> As mentioned above, the use of the resin molded article is not particularly limited, and examples thereof include electromagnetic wave shielding.

[0120] Another embodiment of the present invention includes the above-mentioned resin molded body. Electronic devices, cables, smartphones, tablets, smart watches, smart security devices, surveillance devices or telecommunications equipment such as smart appliances; Consumer electronic devices such as computer circuitry, radio transmitters (including smartphones), electric motors, and flat panel or liquid crystal displays (LCDs): Automotive equipment such as safety systems, mobile media, communications, wireless headsets, battery-powered, electric, hybrid powertrains, or high-voltage battery systems; Medical devices such as smart beds, ventilators, CT scan machines, or transducers that need to capture information such as pulse and blood pressure and convert it into electronic signals; Aerospace or defense equipment such as aircraft, vehicles, combat aircraft materials, weapons, elastomeric gaskets, conductive paints, or EMI shielding displays; Systems such as railway systems, mass transit systems, high voltage contact switching systems, signaling systems, or control systems; or Digital weapons such as electromagnetic or electronic bombs based on high-power surges; or Other equipment (equipment other than those listed above that may have resin moldings); etc. The use of the resin molded article in each of the above-described embodiments is not particularly limited as long as the resin molded article is included as a component. Furthermore, each of the embodiments is particularly preferably used as an electromagnetic wave shielding sheet.

[0121] In particular, when used as an electromagnetic wave shielding sheet, it can be used in any application that shields electromagnetic waves. For example, by placing the electromagnetic wave shielding sheet so as to surround electronic devices that may malfunction due to electromagnetic waves, such malfunctions can be suppressed. In particular, the above-mentioned electromagnetic wave shielding sheet is superior to conventional electromagnetic wave shielding sheets in shielding electromagnetic waves in the high-frequency band, and therefore can be applied to a wider range of fields than conventional electromagnetic wave shielding sheets in that it can shield against electromagnetic waves originating from communication devices such as mobile phones and smartphones, which are increasingly being deployed at higher frequencies, particularly high frequency bands of 100 GHz or higher, in order to achieve higher speeds, larger capacities, and lower latency. Note that the above-mentioned sheet achieves a particularly strong electromagnetic wave shielding effect when the plane of the sheet is perpendicular to the direction in which electromagnetic waves arrive from outside. [Example]

[0122] The present disclosure will be described in more detail below with reference to examples, but the present disclosure should not be construed as being limited to the following examples.

[0123] <Experiment A> <Experiment A1: Simulation Evaluation> Using ANSYS HFSS (registered trademark), a full-wave 3D electromagnetic field software manufactured by Cybernet Systems Co., Ltd., a simulation experiment was conducted to evaluate the effect of the tilt of the central axis of the conductive material on the electromagnetic wave shielding performance L (dB).

[0124] [x-axis tilt experiment] As shown in Figure 9 (air 1, substrate 2, copper coil 3), a copper (Cu) coil was used as the conductive member, and an x-axis tilt experiment was conducted in which the angle between the central axis of the coil and the y-axis was set to 90°, and the angle between the central axis of the coil and the x-axis was set to θ. The experimental conditions for this simulation experiment are as follows: In Figure 9(a), the polarization direction of the electric field of the incident electromagnetic wave was set to the -y-axis direction, and the polarization direction of the magnetic field was set to the -x-axis direction. Substrate material: Epoxy resin (the real part of the dielectric constant is 3.65, and the imaginary part of the dielectric constant is 0.05) Substrate thickness: 1000μm Coil plasma angular frequency (ω ρ ): 1.12×10 16 rad / s Coil damping angular frequency (ω τ ): 1.38×10 13 rad / s Coil outer diameter: 153.6 μm Wire outer diameter: 20μm Coil winding pitch: 40μm Number of turns: 24.33 Coil alignment pitch: 1500μm Initial mesh resolution: Coarse When the initial mesh resolution was set to Coarse and Normal, the electromagnetic shielding effectiveness L was compared for each of the conditions where the angle θ between the central axis of the coil and the x-axis was 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, and 90°. The results are shown in Figures 10 to 13. The electromagnetic shielding effectiveness L (dB) was calculated using the above-mentioned formulas (A) and (B).

[0125] [Y-axis tilt experiment] As shown in Figure 14 (air 1, substrate 2, copper coil 3), a copper (Cu) coil was used as the conductive member material, and the angle between the center axis of the coil and the x-axis was set to 90°, and the angle between the center axis of the coil and the y-axis was set to θ. x Under the same experimental conditions as the axial tilt experiment y Axial tilt experiments were carried out. The above x As in the axis tilt experiment, when the resolution of the initial mesh was set to Coarse and Normal, and the angle θ between the central axis of the coil and the y-axis was set to 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, and 90°, the electromagnetic shielding effectiveness L was compared. The results are shown in Figures 15 to 18. The electromagnetic shielding effectiveness L (dB) was calculated using the above-mentioned formulas (A) and (B).

[0126] 10 to 13 and 15 to 18 show that as the angle between the plane of the sheet and the central axis increases, the electromagnetic shielding performance L decreases in high frequency bands, particularly at frequencies above 100 GHz, and even at frequencies around 300 GHz, i.e., the electromagnetic shielding performance improves. Furthermore, when considering the second resin molding, a double coil having a major helix and a minor helix has more portions with angles that provide a good effect than a single coil without a minor helix, and therefore has excellent electromagnetic shielding performance.

[0127] <Experiment A2: Evaluation of actual seats> [Sample production] <Raw materials> Base material 1: Semiconductor molding resin R4212-2 manufactured by Nagase & Co., Ltd. The base material 1 is composed of 89% by weight of silica filler SiO2, 10% by weight of epoxy resin, and others (flame retardant, carbon black, ion trapping agent, etc.) and has a refractive index of 1.93 at 500 GHz. Base material 2: A mixture of Struers cold mounting resin JP-21111001 (polyester resin, refractive index at 500 GHz: 1.69) and Struers hardener (M agent) The mixing ratio of cold mounting resin:hardener is 100 ml:1.5 ml, and the hardening time is 40 minutes at room temperature. Conductive member: In each example, a coil having the form shown in Table 1 below was used as the conductive member.

[0128] (Example A1) The base material 1 was poured into a mold capable of producing a sheet with an overall size of 30 mm (length) x 30 mm (width) and with 350 μm outer diameter pockets (through holes) spaced 1 mm apart from each other (grid arrangement), with the hole centers spaced 1 mm apart. The center-to-center distance between the holes was the coil alignment pitch. At this time, the grid-like arrangement of the pockets was positioned at the center of the sheet, i.e., the center of the grid-like arrangement was aligned with the center of the sheet. Then, the base material 1 was heated at a curing temperature of 120°C for 10 minutes to obtain a cured sheet, and the cured sheet was then placed in an oven and heated at 150°C for 60 minutes to obtain a pocket-containing sheet 1. Thereafter, metal coils were arranged in all pockets of this pocket-containing sheet so that the average angle between the central axis of the metal coil and the planar direction of the sheet was 81.4°. The metal coils were made of metal wires with a circular cross section, with a metal wire thickness (strand diameter) of 30 μm, an outer diameter of the metal coil of 300 μm, a length in the central axis direction of 3 mm, and a winding pitch width of 60 μm. The coil alignment pitch was the center-to-center distance between the holes of the pockets. Note that a metal coil with a length in the central axis direction of 3 mm was used, but was ground to 1 mm in the thickness direction of the sheet in the final sheet grinding process. Similarly, in the other examples and comparative examples below, metal coils with a length in the central axis direction of 3 mm were used, but were ground to the final sheet thickness in the thickness direction of the sheet in the final sheet grinding process. Furthermore, copper metal wires were used. Thereafter, while maintaining the arrangement of the metal coils, the same resin as that of the base material 1 was poured into each pocket of the sheet and cured under the same curing conditions as those described above. The resulting sheet was then ground to a thickness of 1 mm to obtain the 1 mm thick sheet 1. The average number of turns of the metal coils was 17, the average weight per coil was 0.00043489 g, and the content of the metal coils in the sheet was 0.0675 g / cm. 3 It was.

[0129] (Example A2) Sheet 2 was produced in the same manner as in Example A1, except that the coil alignment pitch of the metal coils was changed to 2 mm, the number of metal coils was changed to 15 (vertical) × 15 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was changed to 72.8°. Sheet 2 was obtained. The content of the metal coil in Sheet 2 was 0.0169 g / cm. 3 It was.

[0130] (Example A3) A sheet was produced in the same manner as in Example A1, except that the resin used was Base Material 2, the metal wire was made of tungsten, the coil arrangement pitch was 0.75 mm, the number of coils was 40 (vertical) × 40 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was 72.1°. Sheet 3 was obtained by producing the sheet in the same manner as in Example A1. The average number of turns of the metal coil was 33, and the content of the metal coil in Sheet 3 was 0.2577 g / cm. 3 It was.

[0131] (Example A4) A sheet was produced in the same manner as in Example A1, except that the resin used was Base Material 2, the metal wire was tungsten, the coil outer diameter was 200 μm, the coil arrangement pitch was 0.75 mm, the number of coils was 40 (vertical) × 40 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was 81.0°. Sheet 4 was obtained by producing the sheet in the same manner as in Example A1. The average number of turns of the metal coil was 33, and the content of the metal coil in Sheet 4 was 0.1718 g / cm. 3 It was.

[0132] (Example A5) A sheet was produced in the same manner as in Example A1, except that the resin used was base material 2, the metal wire was tungsten, the outer diameter of the metal coil was 100 μm, the coil arrangement pitch was 0.75 mm, the number of metal coils was 40 (vertical) × 40 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was 81.2°. Sheet 5 was obtained by producing the sheet in the same manner as in Example A1. The average number of turns of the metal coil was 33, and the content of the metal coil in Sheet 5 was 0.0859 g / cm. 3 It was.

[0133] (Example A6) A sheet was produced in the same manner as in Example A1, except that the resin used was changed to Base Material 2, the metal wire was changed to tungsten, the outer diameter of the metal coil was changed to 100 μm, the coil arrangement pitch was changed to 0.50 mm, the number of metal coils was changed to 60 (vertical) × 60 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was changed to 83.4°. Sheet 6 was obtained by producing the sheet in the same manner as in Example A1. The average number of turns of the metal coil was 33, and the content of the metal coil in Sheet 6 was 0.1933 g / cm. 3 It was.

[0134] (Comparative Example A1) A sheet was produced in the same manner as in Example A1, except that the coil alignment pitch of the metal coils was changed to 3 mm, the number of metal coils was changed to 10 (vertical) × 10 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was changed to 23.6°, to obtain Sheet 7. The average number of turns of the metal coil was 17, and the content of the metal coil in Sheet 7 was 0.0075 g / cm. 3 It was.

[0135] (Comparative example A2) A sheet was fabricated using a wire bonder manufactured by Hesse Mechatronics by performing the following operations. First, as shown in FIGS. 19(a) and 19(b), 15 copper metal coils 42, each having the same thickness (wire diameter), outer diameter, and winding pitch width as those in Example A1 and a length of 1 mm in the central axis direction, were arranged in parallel on an aluminum plate 41. Then, a wedge tool 43 was struck against each coil at intervals of 1 mm to crush a portion of the coil. Then, as shown in FIG. 19(c), tweezers were inserted under the uncrushed portion, lifting it up and holding it in that state (the coil in this state is referred to as a continuous horizontal coil). The number of metal coils is the number of uncrushed portions, and when the central axis direction of the metal coil is taken as the vertical direction, a 15 (vertical) × 15 (horizontal) grid-like arrangement was obtained. The length of the metal coil in the central axis direction was the length of the uncrushed portion, which was 0.7333 mm. The coil alignment pitch, which was the interval between strikes of the wedge tool, was 2 mm. The base material 1 was then poured onto an aluminum plate so as to include the continuous horizontal coil, cured under the same resin curing conditions as in Example A1, and then peeled off from the aluminum plate to obtain a cured sheet. The sheet was produced to an overall size of 3 cm x 3 cm. Finally, the resulting cured sheet was ground to a thickness of 1 mm to obtain Sheet 8, which was 1 mm thick. The average number of turns of the metal coil was 17, the average angle between the central axis of the metal coil and the planar direction of Sheet 8 was 10.4°, and the content of the metal coil in Sheet 8 was 0.0292 g / cm. 3 Furthermore, Sheet 8 was produced so that the lattice arrangement of the metal coils was at the center of the sheet, that is, so that the center of the lattice arrangement and the center of the sheet overlapped.

[0136] (Comparative example A3) A sheet was produced in the same manner as in Comparative Example A2, except that the coil alignment pitch of the metal coils was changed to 3 mm, the number of metal coils was changed to 30 (vertical) × 30 (horizontal), and the average angle between the central axis of the metal coil and the planar direction of the sheet was changed to 10.6°, to obtain Sheet 9. The average number of turns of the metal coil was 17, and the content of the metal coil in Sheet 9 was 0.0205 g / cm. 3 It was.

[0137] (Comparative example A4) Without using a metal coil, the base material 1 was cured under the same resin curing conditions as in the above examples to obtain the sheet 10.

[0138] (Comparative Example A5) The metal coil was replaced with a copper cylinder with an outer diameter of 30 μm, and the alignment pitch of the cylinders was set to 1.0 mm. A sheet was produced in the same manner as in Example A1, except that the number of cylinders was 30 (vertical) x 30 (horizontal) and the average angle between the central axis of the cylinder and the plane direction of the sheet was 82.7°, to obtain Sheet 11. Cylinder The content is 0.0063g / cm 3 It was.

[0139] (Comparative example A6) A sheet was produced in the same manner as in Comparative Example A5, except that the outer diameter of the cylinders was 300 μm, the alignment pitch of the cylinders was 2.0 mm, the number of cylinders was 15 (vertical) × 15 (horizontal), and the average angle between the central axis of the cylinders and the planar direction of the sheet was 82.8°, to obtain Sheet 12. Cylinder The content is 0.1583g / cm 3 It was.

[0140] [Characteristics evaluation] (Electromagnetic wave shielding) The electromagnetic wave shielding property was evaluated by measuring the power transmittance T(ω) using a terahertz spectroscopy system (TAS7500TSH manufactured by Advantest Corporation). The aperture used had a diameter of 10 mm. The samples to be measured were cut out from each of the above sheets into rectangular parallelepipeds with a side length of 30 mm and a thickness of 1 mm. Next, the shielding performance L (dB) was calculated from the power transmittance T (ω) obtained by the measurement according to the following formula (B). L=10×Log 10 (T(ω) / 100) (B) Table 1 shows the evaluation results of the electromagnetic wave shielding performance L of each sheet. In addition, in the shielding performance in Table 1, the frequency shown in parentheses is the frequency used to evaluate that performance. The frequency was selected to be 50 GHz or higher, and one of the frequencies at which a large peak was observed compared to other parts in the evaluation of electromagnetic wave shielding performance L. In Comparative Examples A1 to A6, no large peak was observed at 50 GHz or higher (noise peaks were not taken into consideration).

[0141] [Table 1]

[0142] From Table 1 above, it can be seen that the sheets of Examples A1 to A6, which meet the requirements of each of the above embodiments, achieved a significant electromagnetic wave shielding effect in any frequency band above 100 GHz, but the sheets of Comparative Examples A1 to A6, which do not meet the requirements, did not achieve such an effect. In addition, a comparison between Examples A1 and A2 and Example A5 A Comparison with 6 shows that the electromagnetic shielding effect at frequencies above 50 GHz increases as the coil alignment pitch decreases. Furthermore, a comparison between Examples A4 and A5 revealed that an increase in the coil outer diameter increased the electromagnetic wave shielding effect at frequencies of 50 GHz or higher.

[0143] <Experiment B> <Experiment B1: Evaluation of actual seats> [Sample production] <Raw materials> Base material 1: A mixture of Struers cold mounting resin JP-21111001 (polyester resin, refractive index at 500 GHz: 1.69) and Struers hardener (M agent) The mixing ratio of cold mounting resin:hardener is 100 ml:1.5 ml, and the hardening time is 40 minutes at room temperature. Base material 2: Semiconductor molding resin R4212-2 manufactured by Nagase & Co., Ltd. The base material 2 is composed of 89% by weight of silica filler SiO2, 10% by weight of epoxy resin, and others (flame retardant, carbon black, ion scavenger, etc.), and has a refractive index of 1.93 at 500 GHz. Coil: In each example, a coil having the configuration shown in Table 2 below was used.

[0144] Example B1 A mold was prepared having pockets (through holes) with a hole depth of 2 mm and an outer diameter of 350 μm, spaced at a center-to-center distance of 0.750 mm, in a 40-by-40 grid pattern. Then, as shown in FIG. 24(a), the following was inserted into the holes of the mold 36: DaThe double coils 37 were arranged in a 16-by-16 arrangement, with 34.8 double coils per circle of 5 mm diameter in the sheet plane direction. The double coils 37 were made of metal wire with a circular cross section, with the metal wire having a thickness (strand diameter) of 30 μm, the major spiral outer diameter of 300 μm, the major spiral winding pitch width of 180 μm, the minor spiral outer diameter of 90 μm, and the minor spiral winding pitch width of 60 μm. The coil alignment pitch was the center-to-center distance between the holes in the pockets. The double coils used had a length of 3 mm in the direction of the central axis of the major spiral, but were ground to 2 mm in the thickness direction of the sheet in the final sheet grinding process. The metal wire used was A tungsten one was used. Thereafter, as shown in FIG. 24(b), a silicon plate 38 coated with a resin 39 made of the base material 1 is placed so that the resin 39 comes into contact with the double coil 37, and the resin 39 is then applied to the silicon plate 38 at normal temperature. Warm The resin 39 was left to harden for 40 minutes, and the double coil 37 was fixed to the resin 39. The double coil 37 was then removed from the mold 36, and while the double coil was still fixed, resin 39 was poured in and heated to harden, producing a sheet (30 mm (length) × 30 mm (width)) as shown in Figure 24(c). The heating was carried out by leaving the resin at room temperature for 40 minutes to harden, and a hardened sheet was obtained. The lattice-like arrangement of the double coil was positioned at the center of the sheet, that is, the center of the lattice-like arrangement and the center of the sheet were overlapped. Finally, the silicon plate 38 was removed, and the sheet was ground to a thickness of 2 mm, yielding a 2 mm thick sheet 1. The average angle between the central axis of the double coil's major spiral and the plane direction of the sheet was 85.4°, the average weight per double coil was 0.000180 g, and the content of double coil in sheet 1 was 0.2295 g / cm 3 It was.

[0145] (Example B2) Base material 1 was mixed with the same double coil as used in Example B1, and the resulting mixture was poured into a mold capable of producing a sheet with an overall size of 30 mm (length) x 30 mm (width). 573 double coils were arranged so that three double coils were stacked in multiple locations (so that multiple bundles of three stacked coils existed) and 12.5 double coils were present within a 5 mm diameter circle in the sheet plane direction. Base material 1 was then cured under the same curing conditions as base material 1 in Example 1 and ground to a thickness of 2 mm to obtain sheet 2 with a thickness of 2 mm. During this process, the double coils in base material 1 settled in the resin, and most of the double coils were tilted in the plane direction. Base material 1 was cured in this state. The average angle between the central axis of the large helix of the double coil and the plane direction of the sheet was 4.4°. The double coil content in sheet 2 was 1.1619 g / cm 3 In Example 1, the final length of the double coil's large spiral in the central axis direction was 2 mm in the thickness direction of the sheet due to grinding of the sheet, but in this Example B2, the double coil was tilted almost horizontally and was not ground, so the length of the double coil's large spiral in the resin in the central axis direction was the original length of 3 mm. When the electromagnetic shielding property described below was evaluated using the above-mentioned sheet 2, the electromagnetic shielding performance L at 520 GHz was found to be -13.1 dB. In this embodiment, an average of three double coils are stacked, so the thickness of the double coils in the thickness direction of the sheet is essentially 300 μm × 3 layers = 900 μm. Therefore, since the resin has almost no effect on the electromagnetic shielding property, the above-mentioned electromagnetic shielding performance L value of -13.1 dB can be considered to be the electromagnetic shielding performance L of a sheet with 900 μm of double coils stacked in the thickness direction. Therefore, in an embodiment in which the double coils are stacked 2 mm in the thickness direction of the sheet, the electromagnetic shielding performance L is -13.1 × (2000 μm / 900 μm) = -29.1 dB. Table 2 below shows the electromagnetic shielding performance L for an embodiment in which the double coils are stacked 2 mm.

[0146] (Comparative Example B1) Without using a metal coil, the base material 1 was cured under the same resin curing conditions as in Example B1 above to obtain a sheet 3 of 30 mm (length) x 30 mm (width) x 2 mm (thickness).

[0147] (Comparative example B2) A sheet was fabricated using a wire bonder manufactured by Hesse Mechatronics by performing the following operations. First, as shown in FIGS. 19(a) and (b), 15 copper metal coils (single coils) 42, each having the same thickness (wire diameter), outer diameter, and winding pitch as those in Example B1 and a length of 1 mm in the central axis direction, were arranged in parallel on an aluminum plate 41. Then, a wedge tool 43 was struck against each single coil at intervals of 3 mm to crush a portion of the single coil. Then, as shown in FIG. 19(c), tweezers were inserted under the uncrushed portion, lifting it up and holding it in that state (the single coil in this state is referred to as a continuous horizontal coil). The number of single coils refers to the number of uncrushed portions. When the central axis direction of the single coils is taken as the vertical direction, a 30 (vertical) × 30 (horizontal) lattice-like arrangement was obtained. The length of the single coil in the central axis direction, which is the length of the uncrushed portion, was 0.7333 mm. The coil alignment pitch was 3 mm, which was the interval between strikes of the wedge tool. The base material 2 was then poured onto an aluminum plate so as to include the continuous horizontal coil. The base material was cured under the same conditions as in Example B1, and then peeled off from the aluminum plate to obtain a cured sheet. The sheet was produced to have an overall size of 3 cm x 3 cm. Finally, the cured sheet was ground to a thickness of 1 mm to obtain Sheet 4, which was 1 mm thick. The average number of turns of the single coil was 17, the average angle between the central axis of the single coil and the planar direction of Sheet 8 was 10.6°, and the content of the single coil in Sheet 4 was 0.0205 g / cm. 3Furthermore, Sheet 4 was produced so that the lattice arrangement of the single coils was at the center of the sheet, that is, so that the center of the lattice arrangement and the center of the sheet overlapped. In Table 2 below, the winding pitch width and outer diameter of the single coil are shown in the columns for large spiral winding pitch width and large spiral outer diameter, respectively.

[0148] [Characteristics evaluation] (Electromagnetic wave shielding) The electromagnetic wave shielding property was evaluated by measuring the power transmittance T(ω) using a terahertz spectroscopy system (TAS7500TSH manufactured by Advantest Corporation). The aperture used had a diameter of 5 mm. The samples to be measured were cut out from each of the above sheets into rectangular parallelepipeds with a side length of 30 mm and a thickness of 1 mm. Next, the shielding performance L (dB) was calculated from the power transmittance T (ω) obtained by the measurement according to the following formula (B). L=10×Log 10 (T(ω) / 100) (B) The evaluation results of the electromagnetic shielding performance L of each sheet are shown in Table 2 below. Note that the frequency shown in parentheses in Table 2 for the shielding performance L is the frequency used in evaluating that performance. The frequency was selected to be one that was on the relatively high frequency side and at which a larger peak was observed compared to other parts in the evaluation of the electromagnetic shielding performance L. In Comparative Examples B1 and B2, no large peak was observed in the high frequency band (noise peaks were not taken into consideration).

[0149] [Table 2]

[0150] From Table 2 above, it can be seen that the sheets of Examples B1 and B2, which satisfy the requirements of each of the above embodiments, exhibited a significant electromagnetic wave shielding effect in the high frequency band above 100 GHz, while the sheets of Comparative Examples B1 and B2, which do not satisfy the requirements, did not exhibit such an effect. Both Examples B1 and B2 exhibited an electromagnetic wave shielding effect in the very high frequency band of 500 GHz or more, and are therefore fully applicable not only to applications requiring electromagnetic wave shielding in such frequency bands, but also to next-generation mobile phones and smartphones that are expected to be used in very high frequency bands. It is also clear that the sheet of Example B2, in which the double coil is arranged horizontally, has superior electromagnetic wave shielding properties compared to the sheet of Example B1, in which the double coil is arranged vertically.

[0151] <Reference Experiment B1: Simulation Evaluation (Double Coil)> A simulation experiment was conducted to evaluate the electromagnetic wave shielding effectiveness of a seat containing a double coil using ANSYS HFSS (registered trademark), a full-wave 3D electromagnetic field software manufactured by Cybernet Systems Co., Ltd. Note that the results of "Experiment A1: Simulation Evaluation" above can be used to evaluate the electromagnetic wave shielding effectiveness of a seat containing a single coil.

[0152] [Vertical experiment] As shown in FIG. 25, a simulation experiment was carried out in which a double coil was placed in a sheet so that the angle formed by the sheet plane direction and the central axis of the large spiral of the double coil was perpendicular. The experiment was carried out under the following conditions and those shown in Table 3 below. The propagation direction of the electromagnetic wave was from top to bottom (-Z direction) relative to the thickness direction of the sheet. The polarization direction of the electric field of the incident electromagnetic wave was the X-axis direction, and the polarization direction of the magnetic field was the Y-axis direction. A to C in Table 3 are parameters shown in FIG. 26. Specifically, when the central axis direction side of the large spiral is the inside, the coil winding pitch width on the inside of the small spiral is A, and outsideThe coil winding pitch width at the end is C, and the coil winding pitch width at the midpoint between these is B. The average winding pitch width q of the small spiral described above corresponds to C above. Substrate material: Epoxy resin (the real part of the dielectric constant is 3.65, and the imaginary part of the dielectric constant is 0.05) Tungsten coil plasma angular frequency (ω ρ ):9.71×10 15 rad / s Tungsten coil damping angular frequency (ω τ ): 9.15×10 15 rad / s Initial mesh resolution: Coarse Average length of the double coil in the direction of the central axis of the large spiral: 2 mm (same as the thickness of the resin)

[0153] As in Experiment 1 above, the shielding properties in Table 3 were evaluated using the electromagnetic shielding performance L calculated using the aforementioned formulas (A) and (B), and the frequencies shown in parentheses are the frequencies used to evaluate that performance. The frequency selected was one that was relatively high and showed a larger peak than other parts in the evaluation of the electromagnetic shielding performance L. Fig. 27 shows a graph showing the change in electromagnetic shielding performance L versus the electromagnetic wave frequency for Level 1.

[0154] [Table 3]

[0155] [Horizontal experiment] As shown in FIG. 28, a simulation experiment was carried out in which the double coil was placed in the sheet so that the angle formed by the sheet plane direction and the central axis of the large spiral of the double coil was horizontal. The experiment was carried out under the following conditions and those shown in Table 4 below. The propagation direction of the electromagnetic wave was from top to bottom (-Z direction) relative to the thickness direction of the sheet. The polarization direction of the electric field of the incident electromagnetic wave was the X-axis direction, and the polarization direction of the magnetic field was the Y-axis direction. A to C in Table 4 are the same as A to C in the vertical direction experiment. X is the angle formed by the central axis of the double-coil large helix and the X axis, as shown in FIG. Substrate material: Epoxy resin (the real part of the dielectric constant is 3.65, and the imaginary part of the dielectric constant is 0.05) Tungsten coil plasma angular frequency (ω ρ ):9.71×10 15 rad / s Tungsten coil damping angular frequency (ω τ ): 9.15×10 15 rad / s Initial mesh resolution: Coarse Average length of the double coil in the direction of the central axis of the large spiral: 2 mm (same as the thickness of the resin)

[0156] As in Experiment 1 above, the shielding properties in Table 4 were evaluated using the electromagnetic shielding performance L calculated using the aforementioned formulas (A) and (B), and the frequencies shown in parentheses are the frequencies used to evaluate that performance. The frequency selected was one that was relatively high and showed a larger peak than other parts in the evaluation of the electromagnetic shielding performance L. Fig. 30 shows a graph showing the change in electromagnetic shielding performance L versus the electromagnetic wave frequency for Level 5.

[0157] [Table 4]

[0158] From Tables 3 and 4 above, it can be seen that the electromagnetic wave shielding effect in the high frequency band can be obtained whether the angle of the central axis of the large spiral of the double coil relative to the planar direction of the sheet is vertical or horizontal.

[0159] As described above, the present disclosure can provide an electromagnetic wave shield capable of blocking electromagnetic waves in the high frequency band, and a method for manufacturing the same. [Explanation of symbols]

[0160] 1. Air 2 boards 3 copper coils 10 pocket resin sheet 11 Resin 12 Conductive material 13 pockets 20 C-shaped resin sheet containing conductive material 21 Resin 22 C-shaped conductive material 23 Pillar-shaped conductive material 31 Support A 32 Conductive materials 33 Support B 34 Cured product of resin composition S 35 Cured product of resin composition T 36 Mold 37 Conductive coil (double coil) 38 Silicon Plate 39 Resin 41 Aluminum Plate 42 Metal Coil 43 Wedge Tool G Central axis of the Great Spiral H: Central axis of the small spiral

Claims

1. A resin molded body including a resin and a conductive member having a coil shape with a central axis, and having a flat surface on at least a portion thereof, The number of the conductive members in the resin molded body is 5 pieces / cm ２ That's all, The average angle formed by the plane and the central axis is 50° or more.

2. The resin molded article according to claim 1 , wherein the coil shape is a spiral shape.

3. The resin molded article according to claim 2 , wherein the conductive member is a metal coil.

4. 2. The resin molded body according to claim 1, wherein the conductive member is composed of a plurality of C-shaped conductive materials and a columnar conductive material connecting the ends of the plurality of C-shaped conductive materials in the central axis direction.

5. The content of the conductive member in the resin molded body is 0.00040 g / cm ３ Above, 5.50g / cm ３ The resin molded article according to any one of claims 1 to 4, wherein:

6. The resin molded article according to any one of claims 1 to 5, which is in the form of a sheet.

7. The resin molding according to claim 6, which is an electromagnetic wave shielding sheet.

8. A method for producing a resin molded product, the resin molded product including a resin and a conductive member having a coil shape with a central axis, and at least a flat surface, the method comprising: The number of the conductive members in the resin molded body is 5 pieces / cm ２ That's all, a pocket resin member fabrication step of fabricating a resin member having a pocket and at least a flat surface on a portion thereof; a conductive member placement step of orienting and placing the conductive member in the pocket; and a pocket resin curing step of pouring a resin-containing composition into the pocket in which the conductive member is disposed and then curing the composition; and The method for producing a resin molded article, wherein the average angle formed between the plane and the central axis is 50° or more.

9. A method for producing a resin molded product, the resin molded product including a resin and a conductive member having a coil shape with a central axis, and at least a flat surface, the method comprising: The number of the conductive members in the resin molded body is 5 pieces / cm ２ That's all, a C-shaped conductive material-containing resin sheet manufacturing step of manufacturing a plurality of resin sheets each having the resin, a C-shaped conductive material, and a columnar conductive material connected to an end of the C-shaped conductive material; and a lamination step of laminating a plurality of resin sheets so that an end of the C-shaped conductive material on one sheet and a column-shaped conductive material on the other sheet are in contact with each other in the central axis direction; A method for producing a resin molded product, comprising:

10. A method for producing a resin molded product, the resin molded product including a resin and a conductive member having a coil shape with a central axis, and at least a flat surface, the method comprising: The number of the conductive members in the resin molded body is 5 pieces / cm ２ That's all, a conductive member-containing resin composition preparation step of preparing a resin composition containing the resin and a composition containing the conductive member; an orientation step of orienting the conductive member so that the average angle between the planar direction of the resin molded body and the central axis is 50° or more; a curing step of curing a resin composition containing the resin and a composition containing the conductive member while maintaining the orientation of the conductive member; A method for producing a resin molded product, comprising:

11. The method for producing a resin molded article according to any one of claims 8 to 10, wherein the resin molded article is in the form of a sheet.

12. The method for producing a resin molded article according to claim 11, wherein the resin molded article is an electromagnetic wave shielding sheet.

13. The conductive member includes a resin and a conductive coil, and the conductive member constituting the conductive coil is spiral-shaped; The resin molded product is formed so that the central axis of the conductive coil forms a spiral shape.

14. The content of the conductive coil in the resin molded body is 0.02 g / cm ３ Above, 5.00g / cm ３ The resin molded article according to claim 13, wherein the molecular weight is less than 10 ....

15. The resin molded article according to claim 13 or 14, which is in the form of a sheet.

16. The resin molding according to claim 15, which is an electromagnetic wave shielding sheet.

17. A method for producing a resin molded product including a resin and a conductive coil, a conductive coil-containing resin composition curing step of preparing a resin composition containing the resin and a composition containing the conductive coil, and then curing the composition; and the conductive member constituting the conductive coil is spiral-shaped, The central axis of the conductive coil is formed to form a spiral shape. A method for manufacturing a resin molded product.

18. The method for producing a resin molded article according to claim 17, wherein the resin molded article is in the form of a sheet.

19. The method for producing a resin molded article according to claim 18, wherein the resin molded article is an electromagnetic wave shielding sheet.

20. The conductive member includes a resin and a conductive coil, and the conductive member constituting the conductive coil is spiral-shaped; The conductive coil is formed so that the central axis thereof forms a spiral shape.

21. The composition for a resin molded body according to claim 20, which is a composition for an electromagnetic wave shielding sheet.

22. A telecommunications device comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

23. A consumer electronic device comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

24. An automotive device comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

25. A medical device comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

26. An aerospace device comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

27. A defense device comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

28. A system comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

29. A digital weapon comprising the resin molded article according to any one of claims 1 to 7 and 13 to 16.

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