JP2010087372A - Noise suppressor, noise suppressing sheet, painted goods, and manufacturing method for these - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noise suppressor, a noise suppressing sheet, a painted goods, and a manufacturing method for these, capable of exerting noise suppression ability from a high frequency using a conductive particle. <P>SOLUTION: The noise suppressor 10 has a conductive particle 11 distributed through an electric insulating layer 12 in a voltage-applicable condition in between the adjoining conductive particles 11 in the thickness direction. The noise-suppressing sheet can be applied as the coated film of the noise-suppressing sheet and the painted goods. Further, the method for manufacturing the noise-suppressing sheet and the painted goods comprises a step for applying coating composition composed of the conductive particle 11, a binder, and solvent onto a release sheet or a painted object; and then for drying the coating composition. The same coating composition is repeatedly applied and dried at least one cycle on the obtained dry coated film, to constitute the structure in a plurality of layers on the release sheet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a noise suppression body, a noise suppression sheet, a coated article, and a method for manufacturing them. More specifically, the present invention relates to a noise suppressor, a noise suppression sheet, a coated article, and a method for manufacturing the same for suppressing noise by pasting or forming a coating film on a noise (unnecessary electromagnetic wave) source or a transmission line.

In recent years, electronic devices using high frequencies such as mobile phones and personal computers have become widespread, and the mounting density of electronic components on circuits has increased dramatically. The problem of the electromagnetic interference that occurs is getting worse. As a countermeasure against such an electromagnetic interference, it is known to use a noise suppressor, which is used by covering a noise generation source or a transmission line.
The noise suppression body is one that absorbs noise and removes it by converting it into thermal energy, and is distinguished from an electromagnetic wave reflector that only reflects electromagnetic waves.
By the way, the characteristics of electromagnetic waves greatly depend on the distance from the radiation source, and the near field (the region where the distance from the radiation source is closer than the wavelength λ / 2π) and the far field (the distance from the radiation source is more than the wavelength λ / 2π). Is far different). A “noise suppressor” is an absorber that targets the near field, and is distinguished from an electromagnetic wave absorber that targets the far field and absorbs electromagnetic waves transmitted through free space.

Noise suppression bodies are generally molded into a sheet, which suppresses interference of unwanted electromagnetic waves generated by various currents in electronic devices such as personal computers and mobile phones, and unwanted electronic waves from electronic devices. In order to suppress the radiation of the light, it is used by being affixed to such electronic devices or parts inside the devices. In the present invention, the sheet-like noise suppression body is referred to as a noise suppression sheet.
The electromagnetic wave is formed by an electric field wave and a magnetic field wave, and if one of the electric field wave or the magnetic field wave is attenuated, the other is also attenuated. Therefore, as the material for the electromagnetic wave absorber for the far field, one or more of a conductor, a dielectric, and a magnetic material are used. It is considered that conductors and dielectrics attenuate electromagnetic waves by attenuating electric field waves, and magnetic substances attenuate electromagnetic waves by attenuating magnetic field waves.

As a technique using conductive particles, for example, an electromagnetic wave shielding composite material using a coiled carbon fiber piece is known (see Patent Document 1). As a technique using both conductive particles and magnetic particles in combination, for example, an electromagnetic wave absorbing material using coiled carbon which is a conductive material and magnetic particles is known (see Patent Document 2).
On the other hand, as a material for the noise suppressor, a conductor is not used, but a magnetic substance is mainly used. This is because, in the near field targeted by the noise suppressor, induction of the electric field due to the magnetic field generated by the currents flowing in the various wirings inside the electronic device is not yet sufficient, and means to attenuate the magnetic field wave instead of the electric field wave may be taken. This is because it was considered necessary. More specifically, unlike conventional magnetic materials, electrical conductors and dielectrics are converted to thermal energy and attenuated by acting on an electric field. This is because the sheet using the body is considered not to exhibit the ability to suppress the magnetic field noise in the near field generated by the current flowing through the various wirings inside the electronic device.

As the noise suppressor using the magnetic material, for example, a spinel ferrite sintered body, a spherical particle of a hexagonal ferrite sintered body, a flat particle of a metal magnetic body, etc. are mixed in a resin (see Patent Document 3). And those using soft magnetic particles such as iron, iron aluminum silicon alloy, iron nickel alloy, amorphous alloy, and iron oxide (see Patent Document 4).
JP-A-5-21984 JP 2000-232295 A Japanese Patent No. 3401650 JP 2008-98392 A

As described above, suppression of noise in the near field has been conventionally used using magnetic particles, but the applicant of the present application is able to suppress the surface resistance even if conductive particles are used. Has been found to be able to suppress near-field noise by adjusting the current to 10 to 500Ω / □, and a patent application has already been completed for this technique (Japanese Patent Application No. 2007-086054). The applicant of the present application, when applying for a patent for this technology, has a surface resistance value of about 5000Ω / □ of an electromagnetic wave absorber using a conventional conductive material, and the surface resistance value found by the present inventor in the above technology. It has been confirmed that it is far above the optimal range.
The noise suppression body using magnetic particles exhibits noise suppression characteristics from about 1 GHz, while the noise suppression body based on the technology previously filed by the applicant of the present application exhibits noise suppression characteristics from several hundred MHz.

The noise suppressor based on the technology previously filed by the applicant of the present application is superior in that it can suppress noise in a low frequency range than a noise suppressor using conventional magnetic particles, and is used for low frequencies. However, in the case of a high frequency application, the frequency of the main signal is included in the frequency range where the noise suppression characteristic is exhibited, and there is a possibility that not only the noise but also the main signal is suppressed. Therefore, it is necessary to properly use a noise suppressor using conductive particles previously filed by the applicant of the present application for low frequency applications, and a noise suppressor using conventionally known magnetic particles for high frequency applications.
However, in general, magnetic particles are more expensive than conductive particles, and alloys that are widely used as magnetic particles may change in composition due to the effect of shearing during kneading with a binder and are difficult to handle. .

  Therefore, the problem to be solved by the present invention is to use conductive particles that are cheaper and easier to handle than magnetic particles, and have the same noise suppression characteristics as a noise suppression sheet using magnetic particles, that is, from a high frequency. An object of the present invention is to provide a noise suppressing body, a noise suppressing sheet, a coated article, and a manufacturing method thereof that exhibit noise suppressing ability.

The present inventor has intensively studied to solve the above problems.
As a result, in order to solve the above-described problem, the conductive particles made of non-magnetic conductive powder are interposed between the conductive particles adjacent to each other in the thickness direction with an electric insulating layer interposed therebetween. And found that a large number of them should be dispersed. As shown in FIG. 1, this noise suppressor is presumed to have a structure in which resistors and capacitors are alternately arranged. In such a structure, since the current is more likely to flow as the frequency increases, the noise suppressor is specifically high frequency. It is presumed that the noise suppression characteristics on the side will be excellent.
Moreover, the noise suppression sheet | seat which consists of the said noise suppression body, the coating article whose coating film is the said noise suppression body, and these suitable manufacturing methods were also discovered.

That is, the noise suppressor according to the present invention is a noise suppressor in which a large number of conductive particles made of non-magnetic conductive powder are dispersed therein to suppress noise in the near field, and the conductive particles Is characterized in that it is dispersed through an electrically insulating layer in a state where voltage can be applied between conductive particles adjacent in the thickness direction.
The noise suppression sheet | seat concerning this invention consists of the said noise suppression body, It is characterized by the above-mentioned.
The method for producing a noise suppression sheet according to the present invention is a method for producing the noise suppression sheet, wherein a coating composition comprising nonmagnetic conductive particles, a binder, and a solvent is applied onto a release sheet and dried. The multilayer coating film is formed on the releasable sheet by performing the operation of applying and drying the same coating composition as described above on the dried coating film, and then forming the multilayer coating film on the release sheet. Is peeled from the releasable sheet.

The coated article according to the present invention is characterized in that the coating film is composed of the noise suppressing body.
The method for producing a coated article according to the present invention is a method for producing the coated article, wherein a coating composition comprising conductive particles, a binder, and a solvent is applied onto an object to be coated and dried, and then the dry coating obtained is obtained. A multilayer coating film is formed on an object to be coated by performing at least one operation of applying the same coating composition on the film and drying it.

  According to the noise suppressor, the noise suppression sheet, and the coated article according to the present invention, the conductive particles that are cheaper and easier to handle than the magnetic particles are used, and similarly to the noise suppressor using the magnetic particles, the high frequency Therefore, the noise suppression ability can be exhibited. Moreover, according to the manufacturing method of the noise suppression sheet | seat or coated article concerning this invention, the noise suppression sheet | seat or coated article which exhibits the said noise suppression capability can be manufactured.

Hereinafter, although the noise suppression body, noise suppression sheet | seat, coated article, and these manufacturing methods concerning this invention are demonstrated in detail, the scope of the present invention is not restrained by these description, Modifications can be made as appropriate without departing from the spirit of the invention.
[Noise suppressor]
The noise suppressor according to the present invention is a noise suppressor in which a large number of conductive particles made of nonmagnetic conductive powder are dispersed therein, and suppresses noise in the near field, wherein the conductive particles are: Dispersed through the electrically insulating layer in a state where voltage can be applied between the conductive particles adjacent in the thickness direction.

<Noise suppression sheet>
The noise suppression sheet | seat concerning this invention consists of the said noise suppression body.
The thickness of the noise suppression sheet is preferably 30 to 3,000 μm, and more preferably 100 to 1,000 μm. The thinner the thickness, the smaller and lighter it can be, and the electronic component can be used in a circuit with a high mounting density. However, if the thickness is too thin, the noise suppression capability may not be sufficiently developed.
The surface resistance value of the noise suppression sheet is preferably 100,000Ω / □ or more. More preferably, it is 1,000,000 Ω / □ or more. If the surface resistance value of the noise suppression sheet is 100,000 Ω / □ or more, low frequency noise is not suppressed, and therefore, the main signal on the low frequency side is not suppressed. In addition, since it has a high resistance value, there is no fear of short-circuiting even if it is directly attached to the circuit.

The noise suppression sheet preferably has a smooth surface in that it can be easily reduced in size and weight.
<Coated article>
As for the coated article concerning this invention, a coating film consists of the said noise suppression body.
The surface resistance value of the coated article is preferably 100,000 Ω / □ or more, like the noise suppression sheet. More preferably, it is 1,000,000 Ω / □ or more.
Moreover, it is preferable that the coating-film surface of a coated article is smooth similarly to the said noise suppression sheet | seat.

[Conductive particles]
In the noise suppressor according to the present invention, a large number of conductive particles dispersed therein are made of nonmagnetic conductive powder.
Here, non-magnetic means that it has no magnetization characteristic, specifically, that the magnetic permeability is 1.
Although it does not necessarily limit as said electroconductive particle, For example, a metal, an electroconductive metal oxide, a carbon material, a whisker etc. are mentioned, These can be used 1 type or in combination of 2 or more types.

Although it does not necessarily limit as said metal, For example, gold | metal | money, silver, copper, aluminum etc. are mentioned.
The conductive metal oxide is not particularly limited, and examples thereof include zinc oxide, tin oxide, and indium oxide.
The carbon material is not particularly limited, and examples thereof include carbon black, carbon fiber, carbon nanotube, and carbon nanocoil.
Although it does not necessarily limit as said whisker, For example, a potassium titanate whisker etc. are mentioned.

The shape of the conductive particles is not particularly limited, and examples thereof include various shapes such as flakes, short fibers, and spheres. In particular, if it is flakes and / or short fibers, the conductive particles can be oriented so that their length direction is along the surface direction of the noise suppressor, and high frequency noise can be stabilized. Since it can suppress, it is preferable.
Specifically, the conductive particles may be in a dispersed state shown in FIGS. 2 (a) to (c), for example. It can be seen that a large number of thin conductive particles 11 are dispersed through the insulating layer 12 in FIG. 2 (a), thin fibers in FIG. 2 (b), and spherical fibers in FIG. 2 (c).
Although it does not necessarily limit as a particle diameter of the said electroconductive particle, For example, it is preferable that it is 1-500 micrometers. More preferably, it is 10-300 micrometers. If it is less than 1 μm, uniform dispersion in the binder may be difficult, and since the particles are too small, orientation may not contribute as a capacitor function, and noise suppression ability may not be sufficiently exhibited. On the other hand, if it exceeds 500 μm, irregularities are formed on the surface of the noise suppression body, and voids are likely to be generated inside, which may make it difficult to form a sheet.

[Insulation layer]
The insulating layer can be formed, for example, by using an insulating material as a binder for bonding the conductive particles to each other, or by insulatingly coating each conductive particle.
Although it does not necessarily limit as said binder, For example, resin, a pulp, ceramics, etc. are mentioned, What is necessary is just to select the 1 type (s) or 2 or more types suitably according to the use and the objective.
Examples of the resin include, but are not limited to, various elastomers such as chloroprene rubber, acrylonitrile / butadiene rubber, styrene / butadiene rubber, natural rubber, polyisoprene rubber, polyolefin resin, vinylidene chloride resin, polyamide resin, phenol Examples thereof include resins, epoxy resins, acrylic resins, urethane resins, silicone resins, cellulose resins, vinyl acetate resins, and polycarbonate resins.

Examples of the pulp include, but are not limited to, wood pulp, bamboo pulp, esparto pulp, bagasse pulp, boro pulp, and linter pulp.
Examples of the ceramic include, but are not limited to, titanium oxide, magnesium oxide, aluminum oxide, glass and boron nitride, sericite, silicon oxide, and silicon nitride.
In addition, when the conductive coating is applied to each conductive particle, examples of the material include the resin, pulp, and ceramic. For example, as a relatively simple method, a metal is used as the conductive particle, and the surface is oxidized. And an insulating oxide film is formed on the metal surface.

[Blend ratio of conductive particles and insulating material]
The blending ratio of the conductive particles and the insulating material varies depending on the type of the material and cannot be generally specified. For example, when the conductive particles are a metal or a conductive metal oxide, the blending ratio is determined as the insulating material. It is preferable to set it as 50-2,000 weight part with respect to 100 weight part. More preferably, it is 100-1500 weight part.
In the case where the conductive particles are a carbon material, although not limited, for example, the blending ratio is preferably 10 to 1,000 parts by weight with respect to 100 parts by weight of the insulating material. More preferably, it is 20-500 weight part.

In the case where the conductive particles are whiskers, although not limited, for example, the blending ratio is preferably 50 to 2,000 parts by weight with respect to 100 parts by weight of the insulating material. More preferably, it is 100-1500 weight part.
[Other materials]
Other materials may be used for the noise suppressor according to the present invention as long as the effects of the present invention are not impaired. Specifically, for example, magnetic particles can be used.
Examples of the magnetic particles include, but are not limited to, magnetic alloy metals (Sendust, Permalloy) and ferrite. Ferrite is a group of iron oxides having a composition of MO · Fe ₂ O ₃ , where M is a divalent metal ion, such as Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ^2+, etc. It is. It can be obtained by mixing metal oxide particles and iron oxide particles, compression molding, and firing. M is not limited to one kind, and various magnetization characteristics can be generated by mixing two or more kinds in combination to form a solid solution. For example, it can be used as particles having an average particle size of 100 μm or less. For example, the blending ratio of the magnetic particles is preferably 0 to 400 parts by weight with respect to 100 parts by weight of the insulating material. More preferably, it is 20-200 weight part. Although it does not necessarily limit as a particle diameter of the said magnetic particle, For example, it is preferable that it is 1-300 micrometers. More preferably, it is 10-200 micrometers.

Furthermore, you may add 1 type (s) or 2 or more types as needed, a solvent, a dispersing agent, a plasticizer, a crosslinking agent, anti-aging agent, a crosslinking accelerator, a pigment. Examples of the crosslinking agent include 2,5-dimethyl-2,5-bis (tertiary butyl peroxy) hexane, benzoyl peroxide, dicumyl peroxide, ditertiary butyl peroxide, tertiary butyl cumyl peroxide, para Methyl benzoyl peroxide and the like can be used.
[Manufacture and use of noise suppression sheets]
The noise suppression sheet according to the present invention is the same as described above on the dried coating film obtained after applying a coating composition comprising non-magnetic conductive particles, a binder and a solvent on the release sheet and drying. It can be produced by forming a multilayer coating film on a releasable sheet by performing the operation of applying and drying the coating composition one or more times, and peeling the multilayer coating film from the release sheet. it can.

For example, it can be manufactured through steps (a) to (d) shown in FIG. FIG. 3 is a schematic diagram, and the dimensional ratio is different from the actual one. Moreover, process (a)-(d) is only an example of this invention, for example, even if it does not perform process (d), the noise suppression sheet | seat of this invention can be obtained.
In the step (a), nonmagnetic conductive particles, a binder and a solvent are mixed by the mixing means 20 to obtain a raw material mixture 13. At this time, raw materials other than nonmagnetic conductive particles, a binder, and a solvent may be added.
In the step (b), the coating composition 14 obtained by mixing in the step (a) is applied onto the release sheet 40 by the coating means 30. As the coating means 30, what can apply | coat a coating composition thinly is preferable, for example, a doctor blade etc. are used.

In the step (c), after the coating film obtained in the step (b) is dried to obtain the dried coating film 15, the coating composition 14 is further laminated once or more by the coating means 30. Although the drying temperature and drying time for obtaining a dry coating film are not specifically limited, For example, what is necessary is just to dry for 2 to 60 minutes at normal temperature-50 degreeC. Although not particularly limited, the coating composition 14 is laminated, for example, from 1 to 50 times from the viewpoint of sufficiently obtaining the noise suppression characteristics of the present invention, and from the viewpoint of miniaturization and weight reduction. Is preferred.
Although the thickness per layer in the said process (b) and (c) is not specifically limited by the frequency | count of lamination | stacking, For example, it can be set to 1-500 micrometers.

In the step (d), the multilayer coating film 16 obtained in the step (c) is pressurized by the pressing means 50. When pressurizing, in order to avoid adhesion between the multilayer coating film 16 and the pressurizing means 50, the release sheet 40 is placed on the multilayer coating film. By performing this step (d), further thinning can be achieved. Moreover, if the crosslinking agent is used as a raw material, it can bridge | crosslink with pressurization by applying a heat | fever in this process (d). By performing the crosslinking, the strength of the obtained noise suppression sheet is increased. The applied pressure can be, for example, 1 to 200 MPa, and when heating is also performed, the temperature can be 60 to 250 ° C.
After performing said process (a)-(d), a noise suppression sheet | seat can be obtained by peeling a release sheet.

As the nonmagnetic conductive particles and binder, for example, those exemplified above can be used.
The solvent is not particularly limited as long as it can disperse or dissolve nonmagnetic conductive particles and a binder well.
The preferred ranges of the thickness and the surface resistance value of the noise suppression sheet are as described above.
A clear coating layer or a colored coating layer may be formed on the noise suppression sheet for the purpose of protecting or decorating the sheet.
The noise suppression sheet manufactured as described above is suitable for a usage method of effectively suppressing generation and propagation of noise by covering a noise generation source or a transmission line. Examples of the covering object include a mobile phone and a circuit board.

[Manufacture and use of painted articles]
In the coated article according to the present invention, a coating composition comprising conductive particles, a binder, and a solvent is applied onto a target object and dried, and then the same coating composition as described above is applied onto the obtained dried coating film. And it can manufacture by forming a multilayer coating film on a to-be-coated article by performing operation to dry once or more.
Basically, a manufacturing method that is common to the manufacturing method of the noise suppression sheet can be employed. That is, in FIG. 3, the multilayer coating film 16 may be formed not on the release sheet 40 but on the object to be coated 40.

About electroconductive particle, a binder, a solvent, etc., the thing similar to manufacture of a noise suppression sheet should just be used.
Examples of the object to be coated include a housing of an electronic device.
The preferred ranges of the film thickness and the surface resistance value of the coating film are as described above.
Similarly to the noise suppression sheet, a clear coating layer or a colored coating layer may be further formed for the purpose of protecting or decorating the coating film formed on the coated article.
The coated article thus manufactured can be suitably used for an article that suppresses radiation of unnecessary electromagnetic waves from an electronic device, specifically, for example, a casing such as a mobile phone or a laptop computer.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples. Hereinafter, for convenience, “parts by weight” may be simply referred to as “parts”.
In Examples and Comparative Examples to be described later, the surface resistance value and the transmission attenuation rate R _tp are shown. The measurement method of these values is as follows.
<Measurement of surface resistance value>
The surface resistance value was measured by a four-probe method using a resistivity meter (LorestaAP MCP-T400) manufactured by Mitsubishi Oil Corporation.
Here, the four-probe method measures a potential difference V generated between two inner probes when four probes are arranged on a straight line and a current is passed between the two outer probes. This is a method for measuring the resistivity of the material.

<Measurement of transmission attenuation factor _Rtp >
The measurement was performed in accordance with IEC62333-1 and IEC62333-2. Here, the transmission attenuation rate R _tp is expressed by the following expression (1), and the larger the value, the higher the noise suppression capability. In the formula, S ₁₁ is a reflection attenuation rate, and S ₂₁ is a transmission attenuation rate.

〔Example〕
100 parts of silicone rubber as a binder, 400 parts of flat copper powder as conductive particles, 655 parts of hexane as a solvent, 1 of 2,5-dimethyl-2,5-bis (tertiary butyl peroxy) hexane as a crosslinking agent These materials were stirred with a stirrer to obtain a coating composition.
Using a doctor blade, the coating composition was applied on a release sheet made of a fluororesin so as to have a thickness of 25 μm, and dried under reduced pressure at 30 ° C. for 20 minutes using a fan.

On the obtained dried coating film, the coating composition was applied to a thickness of 25 μm in the same manner as described above, and dried under reduced pressure at 30 ° C. for 20 minutes. This operation was repeated 20 times.
After placing a release sheet made of a fluororesin on the obtained multilayer coating film, heat-pressing under conditions of a temperature of 170 ° C. and a pressure of 40 MPa, the multilayer coating film is compressed and at the same time the rubber component is crosslinked, Thereafter, the release sheet was peeled off to obtain a noise suppressing sheet having a thickness of 674 μm.
The surface resistance value of the obtained noise suppression sheet was 5 × 10 ⁵ Ω / □.
[Comparative Example 1]
Comparative Example 1 is a noise suppression sheet based on the technology previously filed by the applicant of the present application (corresponding to Example 2 described in Japanese Patent Application No. 2007-086054).

Specifically, 100 parts of chlorinated polyethylene as a binder, 20 parts of carbon fiber particles having an average fiber length of 8 μm as conductive particles, and 867 parts of toluene as a solvent were used to knead each material to obtain a conductive paste. The paste was applied to a substrate made of aluminum. Next, after drying under reduced pressure at 30 ° C. for 120 minutes using a fan, a noise suppressing sheet having a smooth surface was obtained by peeling from the substrate.
The thickness of the obtained sheet was 35 μm, and the surface resistance value was 65Ω / □.
[Comparative Example 2]
A commercially available noise suppression sheet “R4N” (trade name, manufactured by NEC Tokin Co., Ltd.) obtained by filling magnetic particles in a binder and having a thickness of 500 μm was used as Comparative Example 2.

[Evaluation]
About the noise suppression sheet | seat concerning an Example and Comparative Examples 1 and 2, the graph which shows the change of the transmission attenuation factor _Rtp for every frequency was shown in FIG.
From these results, it is confirmed that the noise suppression sheet of the example exhibits the same noise suppression characteristics as the noise suppression sheet using the magnetic material of Comparative Example 2, that is, the noise suppression characteristics from the high frequency range. did it.
The noise suppression sheet of Comparative Example 1 expresses excellent noise suppression characteristics from the low frequency range, but when used in high frequency applications, the main signal may be suppressed. The noise suppression sheet was not suitable as an equivalent product.

  The noise suppressor, noise suppression sheet, coated article, and manufacturing method thereof according to the present invention cover a mobile phone or a circuit board, and in particular, noise for preventing generation or leakage of high frequency noise and malfunction due to mutual interference. It can utilize suitably as a suppression body, a noise suppression sheet | seat, a coated article, and these manufacturing methods.

It is a schematic diagram showing the electrical state of the noise suppression body concerning this invention. It is a schematic diagram showing the example of the dispersion state of the electroconductive particle in the noise suppression body concerning this invention. It is process drawing showing the example of the manufacturing method of the noise suppression body concerning this invention. It is a graph which shows the transmission attenuation factor _Rtp of the noise suppression sheet _| seat _concerning an Example and Comparative Examples 1 and 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Noise suppression body 11 Conductive particle | grains 12 Insulating layer 13 Raw material mixture 14 Coating composition 15 Dry coating film 20 Mixing means 30 Coating means 40 Release sheet or to-be-coated object 50 Pressurizing means

Claims (11)

  A plurality of conductive particles made of non-magnetic conductive powder are dispersed therein, and a noise suppressor that suppresses noise in the near field, wherein the conductive particles include conductive particles adjacent to each other in the thickness direction. A noise suppressor, wherein the noise suppressor is dispersed through an electrical insulating layer in a state in which a voltage can be applied between the two.   A noise suppression sheet comprising the noise suppression body according to claim 1.   The noise suppression sheet according to claim 2, wherein the surface resistance value is 100,000 Ω / □ or more.   The noise suppression sheet according to claim 2 or 3, wherein the conductive particles are flakes and / or are short fibers, and the length direction is oriented along the surface direction of the sheet.   A method for producing a noise suppression sheet according to any one of claims 2 to 4, wherein the coating composition comprising conductive particles, a binder and a solvent is applied onto a release sheet and dried. The multilayer coating film is formed on the releasable sheet by performing the operation of applying the same coating composition on the dried coating film and drying it once or more, and releasing the multilayer coating film. A method for producing a noise suppression sheet, wherein the sheet is peeled off from the conductive sheet.   The manufacturing method of the noise suppression sheet | seat of Claim 5 including the process of pressurizing a multilayer coating film.   A coated article, wherein the coating film comprises the noise suppressor according to claim 1.   The coated article according to claim 7, wherein the surface resistance value is 100,000 Ω / □ or more.   The coated article according to claim 7 or 8, wherein the conductive particles are flakes and / or short fibers, and the length direction is oriented along the surface direction of the coating film.   A method for producing a coated article according to any one of claims 7 to 9, wherein a coating composition comprising conductive particles, a binder, and a solvent is applied onto an object to be coated and dried, and then obtained. A method for producing a coated article, characterized in that a multilayer coating film is formed on an object to be coated by performing the operation of applying the same coating composition on the coating film and drying it at least once. .   The manufacturing method of the coated article of Claim 10 including the process of pressurizing a multilayer coating film.

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