WO2006095656A1 - Electromagnetic wave absorbing body - Google Patents

Electromagnetic wave absorbing body Download PDF

Info

Publication number
WO2006095656A1
WO2006095656A1 PCT/JP2006/304124 JP2006304124W WO2006095656A1 WO 2006095656 A1 WO2006095656 A1 WO 2006095656A1 JP 2006304124 W JP2006304124 W JP 2006304124W WO 2006095656 A1 WO2006095656 A1 WO 2006095656A1
Authority
WO
WIPO (PCT)
Prior art keywords
electromagnetic wave
wave absorber
absorber according
carbon black
soft magnetic
Prior art date
Application number
PCT/JP2006/304124
Other languages
French (fr)
Japanese (ja)
Inventor
Takuya Okada
Itaru Utsugi
Original Assignee
Denki Kagaku Kogyo Kabushiki Kaisha
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Denki Kagaku Kogyo Kabushiki Kaisha filed Critical Denki Kagaku Kogyo Kabushiki Kaisha
Publication of WO2006095656A1 publication Critical patent/WO2006095656A1/en

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • H05K9/0083—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising electro-conductive non-fibrous particles embedded in an electrically insulating supporting structure, e.g. powder, flakes, whiskers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H01F1/28—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder dispersed or suspended in a bonding agent
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/34—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials non-metallic substances, e.g. ferrites
    • H01F1/36—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials non-metallic substances, e.g. ferrites in the form of particles
    • H01F1/37—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials non-metallic substances, e.g. ferrites in the form of particles in a bonding agent

Definitions

  • the present invention relates to an electromagnetic wave absorber having both magnetic loss characteristics and dielectric loss characteristics.
  • carbon black is lightweight, it does not have ferromagnetism that contributes to the light weight of the sheet! /, So it has no effect on electromagnetic noise with a dominant magnetic field component.
  • Patent Document 2 JP-A-11-8489
  • Patent Document 3 Japanese Unexamined Patent Application Publication No. 2004-336028
  • the present invention has been made in view of the above problems.
  • the present inventor has improved the absorption characteristics while maintaining the workability and moldability required for manufacturing without a significant increase in weight by using specific carbon black and soft magnetic material, and is thin and thick. It was discovered and completed that an electromagnetic wave absorber with excellent accuracy could be obtained.
  • the gist of the present invention is as follows.
  • An electromagnetic wave absorber characterized by comprising an organic binder, and boron solid solution carbon black and a soft magnetic material contained in the organic binder.
  • the inorganic hydroxide is an aluminum hydroxide and the phosphorus compound is red phosphorus
  • the electromagnetic wave absorber as described.
  • the electromagnetic wave absorber of the present invention has excellent electromagnetic wave absorption characteristics, is light and thin, and has excellent productivity.
  • the electromagnetic wave absorber of the present invention contains a specific carbon black and a soft magnetic material in an organic binder, and further includes a flame retardant and other various additives as required.
  • the organic binder used in the present invention is not particularly limited.
  • the organic binder used in the present invention is not particularly limited.
  • Acrylic resin polyethylene resin, polypropylene resin, epoxy resin, polybenzimidazole resin, polybenzoxazole resin, polybenzthiazole resin, polypyrazole resin, polyquinoxaline resin, polyquinazoline Dione resin, polybensoxagen resin, polyindolone resin, polyquinazolone resin, polyindoxyl resin, silicon resin, silicon-epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester Resin, polyamino bismaleimide resin, diallyl phthalate resin, fluorine resin, TPX resin (methyl pentene polymer “trade name of Mitsui Petrochemical Co., Ltd.”), polyimide resin, polyamide imide resin, polyetherimide Oil, Polyamide oil (66—Nylon, MXD—Nylon, Amorphous nylon Etc.), polyester resin (polybutylene terephthalate, polyethylene terephthalate, etc.), polyphenylene sulfide resin, modified polypheny
  • the organic binder may include a curing agent, a curing accelerator, a catalyst, a vulcanizing agent, a lubricant, a release agent, a stabilizer, a light stabilizer, a colorant, a coupling agent, and the like. It may be added.
  • the organic binders include acrylic resins such as acrylic resins, acrylonitrile 'acrylic rubber' styrene resins, acrylonitrile ethylene propylene gene rubber polystyrene resins, and acrylic rubber.
  • Fat or rubber is inexpensive, has high heat resistance, and is relatively easy to handle, and conventionally known molding methods and processes such as doctor blade method, roll molding method, extrusion molding method, injection molding method, press molding method, etc. It is preferable because the methods can be used in appropriate combinations.
  • the carbon black used in the present invention is preferably boron solid solution carbon black.
  • the boron solid solution amount in carbon black is preferably 0.5 to 2.0%, particularly preferably 0.6 to 1.3%.
  • Carbon black having an electrical resistivity measured according to JIS K 1469 is preferably 0.1 ⁇ cm or less, particularly preferably 0.09 ⁇ cm or less.
  • boron solid solution acetylene black having an electrical resistivity measured in accordance with JIS K 1469 of 0.1 ⁇ cm or less is preferable.
  • boron solid solution acetylene black can be produced by the presence of a boron source at the time of thermal decomposition reaction of hydrocarbon and Z or combustion reaction. .
  • This boron solid solution acetylene black is superior to ordinary acetylene black and other carbon blacks in dispersibility in slurries, especially in dispersibility of water alcohol (such as isopropyl alcohol (IPA)) in polar solvents. This means that the mixing process can be remarkably simplified in the manufacturing process.
  • IPA isopropyl alcohol
  • the raw powder may be blended as it is into Noinda rosin, but from the viewpoint of uniform dispersibility in rosin, it is granulated to an average particle size of preferably about 0.1 to 2 mm. You may mix.
  • For granulation of carbon powder it is desirable to use ion-exchanged water as a wetting agent (Japanese Patent Publication No. 1-58227).
  • the granulated product is easily decalcified in the mixing process.
  • appropriate electrical conductivity can be obtained by using boron solid solution acetylene black having an electrical resistivity according to JIS K 1469 of preferably 0.1 ⁇ cm or less, particularly preferably 0.09 ⁇ cm or less. When applied, it exhibits good electromagnetic wave absorption ability. If the resistivity exceeds 0.1 ⁇ cm, the conductivity imparting effect may be inferior and it may be difficult to further improve the electromagnetic wave absorption ability.
  • the boron solid solution carbon black is effective even when added in a small amount, but the absorption characteristics improve as the content increases.
  • the amount of components contained in these organic binders combined with soft magnetic materials and flame retardants increases, it is generally difficult to ensure the formability and thickness accuracy of thin sheets, and the mechanical strength. Also decreases.
  • the upper limit of the boron solid solution carbon black filling amount depends on the amount and properties of other components added at the same time, and thus is not unconditionally defined. Can be secured.
  • the soft magnetic material used in the present invention may be any material such as various soft magnetic metal powders such as Sendust, Permalloy, and electromagnetic stainless steel, or ferrite materials.
  • Fe Ni (Permalloy) alloy Fe Co alloy, Fe Cr alloy, Fe Si alloy, Fe—Al alloy, 6—0: -31 alloy (electromagnetic stainless steel), 6—0: —Eight alloy , Fe-A1 Si alloy (Sendust) and other iron alloys, Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite and Ni-Zn ferrite It is at least one selected from powders having electromagnetic wave absorption characteristics such as.
  • the soft magnetic material in particular, it has a flat shape, and the average aspect ratio represented by “average particle diameter (long diameter) Z average particle diameter (short diameter)” is preferably 2 to 60, particularly preferably 10
  • the soft magnetic material having an average particle size (major axis) of preferably 10 / zm: Lmm, particularly preferably 20-200 m has a filling property when combined with boron solid solution carbon black. Preferable because it shows good electromagnetic wave absorption.
  • the greater the average aspect ratio the greater the synergistic effect of combining and combining with boron solid solution carbon black.
  • the average aspect ratio is greater than 60, the viscosity of the paint is significantly higher. Thus, the filling property tends to decrease.
  • the average aspect ratio is less than 2, the influence of the demagnetizing field increases, and the electromagnetic wave absorption characteristics tend to decrease. Furthermore, when the average particle diameter (major axis) is smaller than 10 ⁇ m, the average aspect ratio is larger than 60, and as in the case, the viscosity becomes remarkably high and the filling property tends to decrease. If the average particle diameter exceeds lmm, it becomes difficult to form a thin sheet even if the aspect ratio is large.
  • the major axis and minor axis of the average particle diameter of the soft magnetic material can be determined by, for example, observing the cut surface of the cured body with a scanning electron microscope at a magnification of 200 to 2000 times, and looking at an arbitrary 100 particles on the cross section.
  • the major axis length and the minor axis length of the obtained particles can be measured by using an image analyzer (for example, “SPICCA-11” manufactured by Nippon Avivos Co., Ltd.) and averaged.
  • boron-soluble carbon black is preferably contained in an amount of 0.5 to 110 parts by volume, particularly preferably 4 to 40 parts by volume with respect to 100 parts by volume of the organic binder.
  • the soft magnetic material is preferably contained in an amount of 60 to 200 parts by volume, particularly preferably 80 to 150 parts by volume.
  • the mixing ratio of boron solid solution carbon black and soft magnetic material is preferably 1 to L000 volume part of boron solid solution carbon black with respect to 100 parts of soft magnetic material, particularly preferably 10 to L00. It is preferable to contain by volume. If it is less than 1 volume part of boron solid solution carbon black, the effect of improving electromagnetic wave absorption characteristics is not observed, and if it exceeds 1000 volume parts, filling properties and molding may be difficult.
  • the electromagnetic wave absorber of the present invention uses an organic binder, which is a combustible material, or boron solid solution carbon black, and some soft magnetic materials are combustible. Therefore, it is necessary to add a flame retardant when flame retardancy is required. However, it is not preferable to use a halogen-based flame retardant because of environmental problems.
  • the flame retardant used as the flame retardant layer used in the present invention is preferably an inorganic hydroxide or phosphorus compound containing no halogen. These flame retardants are preferably contained in an amount of 2 to 300 parts by mass, particularly preferably 5 to 200 parts by mass with respect to 100 parts by mass of the organic binder.
  • the inorganic hydroxide used in the present invention is not particularly limited, and examples thereof include hydroxide-aluminum and hydroxide-magnesium.
  • Inorganic hydroxide is heated Sometimes heat is absorbed due to a dehydration reaction, and the temperature rise is reduced, thus improving heat resistance. Furthermore, after the heat dehydration, acid oxides remain, which is preferable in that the strength is improved.
  • aluminum hydroxide is more preferable because it is inexpensive and has a large effect of imparting flame retardancy.
  • Inorganic hydroxides generally require a larger amount of addition than halogen-based flame retardants in order to impart flame retardancy, and there is concern about the impact on moldability and mechanical properties.
  • Force In the electromagnetic wave absorber of the present invention the influence can be suppressed small by using boron solid solution carbon black.
  • the phosphorus compound used in the present invention is not particularly limited, but includes red phosphorus; -Various phosphate esters such as diphenyl phosphate; metal phosphates such as sodium phosphate, potassium phosphate and magnesium phosphate; polyphosphate ammonia. Of these, red phosphorus is preferred. A small amount of red phosphorus improves the flame retardancy, but in terms of moisture resistance and safety against ignition, the amount of red phosphorus is small.
  • flame retardance can be improved with a small amount of addition by using a phosphorus compound in combination with an inorganic hydroxide compound.
  • Mixing of organic binder, soft magnetic material, boron solid solution carbon powder, flame retardant, etc. is a force that can be manually mixed in small amounts Planetary mixer, hybrid mixer, Henschel mixer, kneader, ball mill In addition, a general mixer such as a mixing roll can be used.
  • the shape of the electromagnetic wave absorber of the present invention is not particularly limited, but is mainly a thin molded body such as a sheet shape, and the processing method thereof is a conventionally known method such as a doctor-blade method.
  • Various molding methods such as extrusion molding, roll molding, injection molding and press molding can be used.
  • the sheet-shaped electromagnetic wave absorber in the present invention is a composite system with a soft magnetic material by using boron solid solution carbon black, the strength decrease is relatively small. Thus, it is possible to obtain strength even with a single layer.
  • polyethylene terephthalate is used to improve workability when mounting sheets on electronic equipment. More preferably, it is combined with a thin film sheet of a high-strength substrate such as PET (polyester) or polyimide.
  • the thickness of the high-strength base material is too thin, the strength reinforcing effect is too small. If the thickness is too thick, the total thickness of the electromagnetic wave absorber is undesirably large.
  • the thickness is preferably in the range of 1-50 / ⁇ ⁇
  • a coating in which an organic binder, a soft magnetic material, boron solid solution carbon black, and a flame retardant are dissolved in a solvent on a thin film sheet of a high-strength substrate is used. It is possible to form a film by applying it with a doctor blade and evaporating the solvent.
  • an organic binder and soft magnetic material prepared in advance, boron solid solution carbon black, and a sheet-shaped electromagnetic wave absorber such as a flame retardant are attached to a thin film sheet of a high-strength substrate via an adhesive layer. It is possible to laminate.
  • the sheet-shaped electromagnetic wave absorber may be provided with an adhesive layer on one surface thereof in consideration of mounting on an electronic device.
  • the pressure-sensitive adhesive layer is composed of only a pressure-sensitive adhesive and has a base material.
  • any known method such as a laminating method is used for laminating the sheet-shaped electromagnetic wave absorbing layer and the thin film sheet or adhesive layer of the high-strength substrate.
  • An acrylic rubber solution was prepared by dissolving acrylic rubber (Nipol AR53L, manufactured by Nippon Zeon Co., Ltd.) in the amount of toluene shown in Table 1.
  • acetylene black manufactured by Denki Kagaku Kogyo
  • boron solid solution acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd., boron content 0.82%, electrical resistivity according to JIS K 1469 0.08 ⁇ cm)
  • metal soft magnetic powder Mitsubishi Materials, JEM powder, average particle aspect ratio a: 20, b: l .5, c: 7, d: 47, average particle diameter (major axis) a: 24 m, 1>: 18 / ⁇ ⁇ , c: 20 ⁇ m, ⁇ : 120 ⁇ m
  • aluminum hydroxide Showa Denko Hygielite H 32, average particle size 8 m
  • an acrylic rubber solution was prepared by dissolving acrylic rubber (Nipol AR 53L, manufactured by Nippon Zeon Co., Ltd.) in the amount of toluene described in Table 1.
  • Acrylic rubber Nipol AR 53L, manufactured by Nippon Zeon Co., Ltd.
  • Ketchen Black manufactured by Mitsubishi Chemical Co., Ltd., Ketjen Black EC
  • graphite powder SGC Corporation, SGP100
  • soft magnetic material manufactured by Mitsubishi Materials Corporation, JEM powder
  • Each of the slurries of Examples 1 to 10 and Comparative Examples 1 to 7 was coated by a doctor blade method on a 10 m-thick PET substrate (manufactured by Mitsubishi Oil Co., Ltd.) via an adhesive layer.
  • the sheet was formed and heated to 70 ° C. to evaporate the solvent, thereby obtaining a sheet-like molded body having a thickness of 100 / zm.
  • an adhesive solution (1717, manufactured by Soken Chemical Co., Ltd.) was prepared on one side of the PET substrate by the doctor blade method, and the coating film was heated to 70 ° C to volatilize the solvent.
  • An adhesive layer with a thickness of 20 m was formed to produce a PET substrate with an adhesive.
  • the boron solid solution amount of the boron solid solution acetylene black used was measured according to the following, and the total boron amount was also determined by subtracting the soluble boron amount.
  • the total amount of boron is 0.5g boron solid solution acetylene black in a platinum dish, add 20ml of 1.5% calcium hydroxide aqueous solution and 5ml acetone, and ultrasonically disperse for 1 hour. It was measured by ashing at 800 ° C for 3 hours in an oxygen stream, then heating and eluting in hydrochloric acid, and quantifying fluorine with ICP-AES.
  • the specific surface area was measured by the BET one-point method using nitrogen gas adsorption.
  • the sheet has a smooth surface and almost no thickness spots.
  • Thickness spots on the sheet are severely cracked, causing problems in use. Or the power of a sheet that has poor fluidity.
  • Example 8-: LO is a comparison of the absorption characteristics and the like of sheets prepared by changing the type of magnetic powder.
  • the composite system of boron solid solution acetylene black and magnetic powder including Example 1 very high absorption characteristics are obtained compared to the magnetic powder alone system (Comparative Examples 1 to 4). It can be seen that in the case of using a magnetic powder having a large size (Example 10), the synergistic effect becomes remarkable.
  • Comparative Example 5 uses ordinary acetylene black in which boron is not dissolved in solid, and compares the performance. As shown in Table 1, the same number of parts as in Example 4 were filled and painted, but the state of the produced sheet was poor and the measured electromagnetic wave absorption characteristics were also lower than in Example 4.
  • Comparative Example 6 uses a ketjen black having a large specific surface area and compares the performance. As shown in Table 1, the same amount of parts as in Example 1 was tried to add a large amount of toluene to fill the paint. Mixing into the slurry was insufficient and uniform coating was possible. Natsuki.
  • Comparative Example 7 uses graphite powder having a small specific surface area and compares the performance. As shown in Table 1, the force of filling the same number of parts as in Example 1 and applying the paint was as follows. The thickness unevenness of the produced sheet was large and the condition was poor, and the measured electromagnetic wave absorption characteristics were also low.
  • a slurry prepared with the same composition as Example 1 was applied onto a PET film treated with a release agent, dried at 70 ° C., and peeled off from PET to obtain a sheet-like molded product.
  • Example 1 Each of the sheets of Example 1 and Example 11 was cut to a width of 10 mm to produce a strip sample, and the tensile strength was measured.
  • the tensile strength of the sheet of Example 1 was 16 MPa, and the sheet from which the PET film of Example 11 was peeled was 0.6 MPa.
  • a slurry prepared with the same composition as in Example 1 was applied on a PET base material having a thickness of 10 m without using an adhesive layer to prepare a coating film having a predetermined thickness.
  • the coating film was heated to 70 ° C. to evaporate the solvent, thereby obtaining a sheet-like molded body.
  • Each of the sheets of Example 1 and Example 12 was cut to a width of 10 mm to produce a strip sample, and an attempt was made to peel off the PET substrate and the electromagnetic wave absorbing sheet.
  • the electromagnetic wave absorber of the present invention is excellent in electromagnetic wave absorption characteristics, is thin and light and has excellent productivity, and is widely used in small portable devices such as digital cameras. be able to.
  • the entire contents of the specification, claims and abstract of Japanese Patent Application No. 2005-062284 filed on March 7, 2005 are cited herein as the disclosure of the specification of the present invention. Incorporated.

Abstract

Disclosed is a light-weight electromagnetic wave absorbing body with excellent productivity which has excellent electromagnetic wave absorption characteristics. Specifically disclosed is an electromagnetic wave absorbing body which contains a boron solid-solubilized carbon black and a soft magnetic material in an organic binder. The electrical resistivity of the boron solid-solubilized carbon black in accordance with JIS K 1469 is not more than 0.1 Ωcm. The soft magnetic material has an average particle aspect ration of 2-60 and an average particle diameter (mean particle length) of from 10 μm to 1 mm. Also disclosed is such an electromagnetic wave absorbing body containing an inorganic hydroxide and/or a phosphorus compound as flame retardant. Further disclosed is such an electromagnetic wave absorbing body combined with a high-strength base or one having an adhesive layer interposed between a high-strength base and the electromagnetic wave absorbing body.

Description

明 細 書  Specification
電磁波吸収体  Electromagnetic wave absorber
技術分野  Technical field
[0001] 本発明は、磁性損失特性と誘電損失特性を併せ持つ電磁波吸収体に関する。  [0001] The present invention relates to an electromagnetic wave absorber having both magnetic loss characteristics and dielectric loss characteristics.
背景技術  Background art
[0002] 近年の電子回路の高集積化および回路を伝送する電気信号の高周波数化に伴い デジタルカメラなどの小型携帯機器の制御基盤内の不要電磁波および筐体外部へ の電磁波漏洩の問題が深刻となっている。この問題を抑制するため磁性損失型およ び誘電損失型の電磁波抑制体をノイズ発生源に添付する方法および筐体の内壁面 に添付する手段が採用されて ヽる (特許文献 1参照)。  [0002] With the recent high integration of electronic circuits and higher frequency of electric signals transmitted through the circuits, the problem of unnecessary electromagnetic waves in the control base of small portable devices such as digital cameras and leakage of electromagnetic waves to the outside of the case is serious. It has become. In order to suppress this problem, a method of attaching a magnetic loss type and dielectric loss type electromagnetic wave suppressor to a noise generation source and a means of attaching to an inner wall surface of a housing have been adopted (see Patent Document 1).
[0003] 近年、携帯機器の小型化、薄層化の流れは著しぐそれに伴って電磁波吸収体に おいても薄型化、軽量ィ匕の要求が厳しくなつている。  [0003] In recent years, the trend toward miniaturization and thinning of portable devices has been remarkable, and the demand for thinner and lighter electromagnetic wave absorbers has become stricter.
一般に、磁性損失型の電磁波吸収体については、磁性損失の増大がノイズ吸収特 性向上のためには重要であり、そのため磁性粉を高充填あるいは厚膜ィ匕することに より吸収効果を得ている。その結果、ノイズ吸収体の重量が増加し、軽量ィ匕が必須の 携帯型電子機器の重量増加を引き起こしている。  In general, for magnetic loss type electromagnetic wave absorbers, an increase in magnetic loss is important for improving noise absorption characteristics. Therefore, an absorption effect can be obtained by high-filling or thick-filming magnetic powder. Yes. As a result, the weight of the noise absorber is increased, and the weight of portable electronic devices in which light weight is essential is increasing.
一方、誘電損失型の電磁波吸収体については、誘電率の向上のため膨張黒鉛、 ケッチェンブラックなどの高比表面積のカーボンブラックをゴム ·榭脂 ·塗料と混合しシ ート状に成形し電磁波吸収体とすることが提案されて ヽる（特許文献 2参照)。  On the other hand, for dielectric loss type electromagnetic wave absorbers, carbon black with a high specific surface area such as expanded graphite and ketjen black is mixed with rubber, resin and paint to improve the dielectric constant, and then molded into a sheet shape. It has been proposed to use an absorber (see Patent Document 2).
この場合、カーボンブラックは軽量のためシートの軽量ィ匕には寄与する力 磁性を 有しな!/、ため、磁界成分が優位な電磁波ノイズに対しては効果が無 、。  In this case, since carbon black is lightweight, it does not have ferromagnetism that contributes to the light weight of the sheet! /, So it has no effect on electromagnetic noise with a dominant magnetic field component.
[0004] そこで、軟磁性材料とカーボン系材料の両者を配合させることが考えられるが、通 常のカーボンブラックでは、混合量の増大に伴って粘度が著しく上昇する。十分な吸 収特性を発現するためには多量に添加する必要があるが、この場合、混練時の作業 性や取り扱い性が低下し、シートの厚さ精度の確保も困難になる他、シートの機械的 強度の低下にもつながる。この欠点は、シートに難燃性が要求され、難燃剤を添加さ せる必要がある場合には、さらに問題となる (特許文献 3参照)。 特許文献 1 :特開平 7— 212079号公報 [0004] Thus, it is conceivable to mix both a soft magnetic material and a carbon-based material. However, in ordinary carbon black, the viscosity increases remarkably as the mixing amount increases. In order to exhibit sufficient absorption characteristics, it is necessary to add a large amount, but in this case, workability and handling at the time of kneading are reduced, and it is difficult to ensure the sheet thickness accuracy. It also leads to a decrease in mechanical strength. This disadvantage becomes a further problem when flame retardancy is required for the sheet and it is necessary to add a flame retardant (see Patent Document 3). Patent Document 1: Japanese Patent Laid-Open No. 7-212079
特許文献 2：特開平 11― 8489号公報  Patent Document 2: JP-A-11-8489
特許文献 3：特開 2004 - 336028号公報  Patent Document 3: Japanese Unexamined Patent Application Publication No. 2004-336028
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0005] 本発明は、上記の問題に鑑みてなされたものである。本発明者は、特定のカーボン ブラックと軟磁性材料を使用することで大きな重量増加を伴うことなぐ製造に必要な 作業性、成形性を維持しつつ吸収特性が向上し、かつ、薄型で厚さ精度に優れた電 磁波吸収体が得られることを知見し完成したものである。 [0005] The present invention has been made in view of the above problems. The present inventor has improved the absorption characteristics while maintaining the workability and moldability required for manufacturing without a significant increase in weight by using specific carbon black and soft magnetic material, and is thin and thick. It was discovered and completed that an electromagnetic wave absorber with excellent accuracy could be obtained.
課題を解決するための手段  Means for solving the problem
[0006] 本発明の要旨は以下のとおりである。 [0006] The gist of the present invention is as follows.
(1)有機系結合材と、該有機系結合材中にホウ素固溶カーボンブラックと軟磁性材 料とが含有されることを特徴とする電磁波吸収体。  (1) An electromagnetic wave absorber characterized by comprising an organic binder, and boron solid solution carbon black and a soft magnetic material contained in the organic binder.
(2)前記ホウ素固溶カーボンブラック力JIS K 1469による電気抵抗率が 0. l Q cm 以下である前記（1)に記載の電磁波吸収体。  (2) The electromagnetic wave absorber according to (1), wherein the boron solid solution carbon black force has an electrical resistivity of 0.1 l Q cm or less according to JIS K 1469.
(3)前記軟磁性材料の平均アスペクト比が 2〜60、平均粒子径 (長径）が m〜l mmである前記（1)又は（2)に記載の電磁波吸収体。  (3) The electromagnetic wave absorber according to (1) or (2), wherein the soft magnetic material has an average aspect ratio of 2 to 60 and an average particle diameter (major axis) of m to l mm.
(4)前記有機系結合材が、アクリル榭脂又はアクリルゴムである前記（1)〜（3)の ヽ ずれかに記載の電磁波吸収体。  (4) The electromagnetic wave absorber according to any one of (1) to (3), wherein the organic binder is acrylic resin or acrylic rubber.
(5)前記有機系結合材 100体積部に対して、ホウ素固溶カーボンブラックが 0. 5〜1 10体積部、軟磁性材料が 60〜200体積部含有される前記（1)〜 (4)の 、ずれかに 記載の電磁波吸収体。  (5) The above-mentioned (1) to (4), wherein 0.5 to 10 parts by volume of boron solid solution carbon black and 60 to 200 parts by volume of soft magnetic material are contained with respect to 100 parts by volume of the organic binder. The electromagnetic wave absorber according to any one of the above.
(6)軟磁性材料 100体積部に対しホウ素固溶カーボンブラック 1〜： LOOO体積部含有 する前記（1)〜（5)の 、ずれかに記載の電磁波吸収体。  (6) Soft magnetic material The electromagnetic wave absorber according to any one of (1) to (5) above, containing boron solid solution carbon black 1 to: LOOO volume part with respect to 100 parts by volume.
(7)さら〖こ、難燃剤を含有する前記（1)〜（6)の 、ずれかに記載の電磁波吸収体。 (7) The electromagnetic wave absorber according to any one of (1) to (6), further comprising Sarasako and a flame retardant.
(8)前記難燃剤が無機水酸化物及び Z又はリン化合物である前記 (7)に記載の電 磁波吸収体。 (8) The electromagnetic wave absorber according to (7), wherein the flame retardant is an inorganic hydroxide and Z or a phosphorus compound.
(9)前記無機水酸ィ匕物が水酸ィ匕アルミニウム、リン化合物が赤リンである前記（8)に 記載の電磁波吸収体。 (9) In the above (8), the inorganic hydroxide is an aluminum hydroxide and the phosphorus compound is red phosphorus The electromagnetic wave absorber as described.
( 10)高強度基材と複合化した前記（1)〜（9)の ヽずれかに記載の電磁波吸収体。 (10) The electromagnetic wave absorber according to any one of (1) to (9), which is combined with a high-strength substrate.
( 11)電磁波吸収体と高強度基材の中間に粘着層を有する前記（10)に記載の電磁 波吸収体。 (11) The electromagnetic wave absorber according to (10), wherein an adhesive layer is provided between the electromagnetic wave absorber and the high-strength substrate.
( 12)前記（1)〜（11)のいずれかに記載の電磁波吸収体を使用した電子機器。 発明の効果  (12) An electronic device using the electromagnetic wave absorber according to any one of (1) to (11). The invention's effect
[0007] 本発明の電磁波吸収体は、電磁波吸収特性に優れ、しかも厚みが薄ぐ軽ぐかつ 、生産性に優れている。  [0007] The electromagnetic wave absorber of the present invention has excellent electromagnetic wave absorption characteristics, is light and thin, and has excellent productivity.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0008] 以下、本発明についてさらに詳しく説明する。 [0008] Hereinafter, the present invention will be described in more detail.
なお、本発明における「部」や「％」は特に規定しない限り質量基準で示す。  In the present invention, “parts” and “%” are based on mass unless otherwise specified.
[0009] 本発明の電磁波吸収体は、有機系結合材中に特定のカーボンブラックと軟磁性材 料とを含有し、さらに、必要に応じて難燃剤その他の各種添加剤を含むものである。 [0009] The electromagnetic wave absorber of the present invention contains a specific carbon black and a soft magnetic material in an organic binder, and further includes a flame retardant and other various additives as required.
[0010] 本発明で使用される有機系結合材としては、特に限定されるものではない。例えば[0010] The organic binder used in the present invention is not particularly limited. For example
、アクリル榭脂、ポリエチレン榭脂、ポリプロピレン榭脂、エポキシ榭脂、ポリべンズイミ ダゾール榭脂、ポリべンズォキサゾール榭脂、ポリべンズチアゾール榭脂、ポリピラゾ ール榭脂、ポリキノキサリン榭脂、ポリキナゾリンジオン榭脂、ポリべンズォキサジェン 榭脂、ポリインドロン榭脂、ポリキナゾロン榭脂、ポリインドキシル榭脂、シリコン榭脂、 シリコン一エポキシ榭脂、フエノール榭脂、メラミン榭脂、ユリア榭脂、不飽和ポリエス テル榭脂、ポリアミノビスマレイミド榭脂、ジァリルフタレート榭脂、フッ素榭脂、 TPX榭 脂 (メチルペンテンポリマー「三井石油化学社製商品名」）、ポリイミド榭脂、ポリアミド イミド榭脂、ポリエーテルイミド榭脂、ポリアミド榭脂（66—ナイロン、 MXD—ナイロン 、アモルファスナイロンなど）、ポリエステル榭脂（ポリブチレンテレフタラート、ポリェチ レンテレフタラートなど）、ポリフエ-レンスルフイド榭脂、変性ポリフエ-レンエーテル 榭脂、ポリアリレート榭脂、全芳香族ポリエステル榭脂、ポリスルホン樹脂、液晶ポリマ ー榭脂、ポリエーテルケトン樹脂、ポリエーテルスルホン榭脂、ポリカーボネート榭脂 、マレイミド変性樹脂、 ABS榭脂、アクリロニトリル 'アクリルゴム'スチレン榭脂、アタリ 口-トリル一エチレン.プロピレン.ジェンゴム一スチレン榭脂、ブチルゴム、アクリルゴ ム、エチレンプロピレンゴム、シリコーンゴム、ポリエステルエラストマ一、ポリブタジェ ン、クロ口プレン、天然ゴム、ポリイソプレンなどのエラストマ一類、又はこれらを適宜に 組み合わせたものである。さらに、必要に応じて、上記有機系結合材には、硬化剤、 硬化促進剤、触媒、加硫剤、滑剤、離型剤、安定剤、光安定剤、着色剤、カップリン グ剤などを添加してもよい。 , Acrylic resin, polyethylene resin, polypropylene resin, epoxy resin, polybenzimidazole resin, polybenzoxazole resin, polybenzthiazole resin, polypyrazole resin, polyquinoxaline resin, polyquinazoline Dione resin, polybensoxagen resin, polyindolone resin, polyquinazolone resin, polyindoxyl resin, silicon resin, silicon-epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester Resin, polyamino bismaleimide resin, diallyl phthalate resin, fluorine resin, TPX resin (methyl pentene polymer “trade name of Mitsui Petrochemical Co., Ltd.”), polyimide resin, polyamide imide resin, polyetherimide Oil, Polyamide oil (66—Nylon, MXD—Nylon, Amorphous nylon Etc.), polyester resin (polybutylene terephthalate, polyethylene terephthalate, etc.), polyphenylene sulfide resin, modified polyphenylene ether resin, polyarylate resin, wholly aromatic polyester resin, polysulfone resin, liquid crystal Polymer resin, polyether ketone resin, polyethersulfone resin, polycarbonate resin, maleimide modified resin, ABS resin, acrylonitrile 'acrylic rubber' styrene resin, tali-tolyl ethylene, propylene, gen rubber, styrene resin Fat, butyl rubber, acrylic rubber Elastomers such as rubber, ethylene propylene rubber, silicone rubber, polyester elastomer, polybutadiene, black mouth plain, natural rubber, polyisoprene, etc., or a combination thereof. Further, if necessary, the organic binder may include a curing agent, a curing accelerator, a catalyst, a vulcanizing agent, a lubricant, a release agent, a stabilizer, a light stabilizer, a colorant, a coupling agent, and the like. It may be added.
[0011] 上記有機系結合材としては、上記の例の中でも、アクリル榭脂、アクリロニトリル'ァ クリルゴム'スチレン榭脂、アクリロニトリル エチレン.プロピレン.ジェンゴムースチレ ン榭脂、アクリルゴムなどのアクリル系榭脂又はゴムは、安価で耐熱性が高ぐし力も 取り扱いが比較的容易であり、ドクターブレード法、ロール成形法、押出成形法、射 出成形法、プレス成形法など、従来公知の成形方法や加工方法を適宜組み合わせ て使用することができるため好ましい。  [0011] Among the above examples, the organic binders include acrylic resins such as acrylic resins, acrylonitrile 'acrylic rubber' styrene resins, acrylonitrile ethylene propylene gene rubber polystyrene resins, and acrylic rubber. Fat or rubber is inexpensive, has high heat resistance, and is relatively easy to handle, and conventionally known molding methods and processes such as doctor blade method, roll molding method, extrusion molding method, injection molding method, press molding method, etc. It is preferable because the methods can be used in appropriate combinations.
[0012] 本発明において使用されるカーボンブラックとしては、ホウ素固溶カーボンブラック が好ましい。カーボンブラック中のホウ素固溶量は、好ましくは 0. 5〜2. 0%であり、 特に好ましくは 0. 6〜1. 3%である。また、カーボンブラックは、 JIS K 1469に従つ て測定された電気抵抗率が好ましくは 0. 1 Ω cm以下、特に好ましくは 0. 09 Ω cm以 下であるものが好適である。なかでも、 JIS K 1469に従って測定された電気抵抗 率が 0. 1 Ω cm以下であるホウ素固溶アセチレンブラックが好ましい。  [0012] The carbon black used in the present invention is preferably boron solid solution carbon black. The boron solid solution amount in carbon black is preferably 0.5 to 2.0%, particularly preferably 0.6 to 1.3%. Carbon black having an electrical resistivity measured according to JIS K 1469 is preferably 0.1 Ωcm or less, particularly preferably 0.09 Ωcm or less. Of these, boron solid solution acetylene black having an electrical resistivity measured in accordance with JIS K 1469 of 0.1 Ωcm or less is preferable.
[0013] ホウ素固溶アセチレンブラックは、特開 2000— 281933号公報に記載されている ように、炭化水素の熱分解反応時および Z又は燃焼反応時にホウ素源を存在させる ことにより製造することができる。このホウ素固溶アセチレンブラックは、通常のァセチ レンブラックや他の各種カーボンブラックに比べてスラリーへの分散性、特に水ゃァ ルコール (イソプロピルアルコール（IPA)など）の極性溶剤への分散性も優れて!/、る という特徴を有し、製造工程の中で、混合する工程を著しく簡略ィ匕できるものである。 さらに、その原粉をそのままノインダー榭脂に配合してもよいが、榭脂への均一分 散性の点から、それを平均粒径が好ましくは 0. l〜2mm程度に造粒して力 配合し てもよい。カーボン粉末の造粒には、イオン交換水を湿潤剤として用いることが望まし い（特公平 1— 58227号公報)。このように造粒されたものは、混合工程で容易に解 石辛される。 [0014] 本発明において、 JIS K 1469による電気抵抗率が好ましくは 0. 1 Ω cm以下、特 に好ましくは 0. 09 Ω cm以下のホウ素固溶アセチレンブラックを用いることにより、適 切な導電性が付与されて、良好な電磁波吸収能力を示すようになる。抵抗率が 0. 1 Ω cmを超えると導電性付与効果が劣り、電磁波吸収能力のさらなる向上が困難とな る場合がある。 [0013] As described in JP-A-2000-281933, boron solid solution acetylene black can be produced by the presence of a boron source at the time of thermal decomposition reaction of hydrocarbon and Z or combustion reaction. . This boron solid solution acetylene black is superior to ordinary acetylene black and other carbon blacks in dispersibility in slurries, especially in dispersibility of water alcohol (such as isopropyl alcohol (IPA)) in polar solvents. This means that the mixing process can be remarkably simplified in the manufacturing process. Furthermore, the raw powder may be blended as it is into Noinda rosin, but from the viewpoint of uniform dispersibility in rosin, it is granulated to an average particle size of preferably about 0.1 to 2 mm. You may mix. For granulation of carbon powder, it is desirable to use ion-exchanged water as a wetting agent (Japanese Patent Publication No. 1-58227). The granulated product is easily decalcified in the mixing process. [0014] In the present invention, appropriate electrical conductivity can be obtained by using boron solid solution acetylene black having an electrical resistivity according to JIS K 1469 of preferably 0.1 Ωcm or less, particularly preferably 0.09 Ωcm or less. When applied, it exhibits good electromagnetic wave absorption ability. If the resistivity exceeds 0.1 Ωcm, the conductivity imparting effect may be inferior and it may be difficult to further improve the electromagnetic wave absorption ability.
[0015] ホウ素固溶カーボンブラックは、少量の添加でも効果があるが、含有量を大きくする につれて吸収特性は向上する。しかしながら、軟磁性材料や難燃剤と合わせたこれ ら有機系結合材中に含有される成分の量が多くなると、一般に薄型シートの成形性、 厚さ精度の確保が困難になるほか、機械的強度も低下する。ホウ素固溶カーボンブ ラックの充填量の上限は、同時に添加する他の含有成分の量や性質によって左右さ れるため一概には規定されないが、通常のカーボンブラックと比較して高充填しても 成形性を確保することが可能である。  [0015] The boron solid solution carbon black is effective even when added in a small amount, but the absorption characteristics improve as the content increases. However, as the amount of components contained in these organic binders combined with soft magnetic materials and flame retardants increases, it is generally difficult to ensure the formability and thickness accuracy of thin sheets, and the mechanical strength. Also decreases. The upper limit of the boron solid solution carbon black filling amount depends on the amount and properties of other components added at the same time, and thus is not unconditionally defined. Can be secured.
[0016] 本発明で使用される軟磁性材料としては、例えば、センダスト、パーマロイ、電磁ス テンレスなど各種軟磁性金属粉、又はフェライト系材料など、任意の材料を使用する ことができる。  [0016] The soft magnetic material used in the present invention may be any material such as various soft magnetic metal powders such as Sendust, Permalloy, and electromagnetic stainless steel, or ferrite materials.
具体的には、 Fe Ni (パーマロイ）合金、 Fe Co合金、 Fe Cr合金、 Fe Si合 金、 Fe—Al合金、 6— 0:—31合金（電磁ステンレス）、 6— 0:—八1合金、 Fe— A1 Si合金（センダスト）などの鉄合金、 Mg—Znフェライト、 Mn—Znフェライト、 Mn— Mgフェライト、 Cu— Znフェライト、 Mg— Mn— Srフェライト、 Ni— Znフェライトなどの フェライト系物質などの電磁波吸収特性を有する粉末から選ばれた少なくとも 1種で ある。  Specifically, Fe Ni (Permalloy) alloy, Fe Co alloy, Fe Cr alloy, Fe Si alloy, Fe—Al alloy, 6—0: -31 alloy (electromagnetic stainless steel), 6—0: —Eight alloy , Fe-A1 Si alloy (Sendust) and other iron alloys, Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite and Ni-Zn ferrite It is at least one selected from powders having electromagnetic wave absorption characteristics such as.
軟磁性材料としては、なかでも、扁平形状を有し、その「平均粒子径 (長径) Z平均 粒子径 (短径)」で表される平均アスペクト比が好ましくは 2〜60、特に好ましくは 10 〜50であり、平均粒子径 (長径）が好ましくは 10 /z m〜： Lmm、特に好ましくは 20〜2 00 mである軟磁性材料は、ホウ素固溶カーボンブラックと組み合わせた場合に、 充填性が良好で大きな電磁波吸収性を示すので好ま 、。平均アスペクト比が大き いほど、ホウ素固溶カーボンブラックとの組み合わせ、複合化による相乗効果は大き くなる傾向を示すが、平均アスペクト比が 60よりも大きくなると、塗料粘度が著しく高く なり、充填性が低下する傾向になる。また、平均アスペクト比が 2より小さくなると、反 磁界の影響が大きくなるため、電磁波吸収特性が小さくなる傾向となる。さらに、平均 粒子径 (長径）が 10 μ mよりも小さ 、場合、平均アスペクト比が 60よりも大き 、場合と 同様に粘度が著しく高くなり充填性が低下する傾向になる。平均粒子径が lmmを超 えるとアスペクト比が大きくても、薄層のシートィ匕が難しくなる。 As the soft magnetic material, in particular, it has a flat shape, and the average aspect ratio represented by “average particle diameter (long diameter) Z average particle diameter (short diameter)” is preferably 2 to 60, particularly preferably 10 The soft magnetic material having an average particle size (major axis) of preferably 10 / zm: Lmm, particularly preferably 20-200 m has a filling property when combined with boron solid solution carbon black. Preferable because it shows good electromagnetic wave absorption. The greater the average aspect ratio, the greater the synergistic effect of combining and combining with boron solid solution carbon black. However, when the average aspect ratio is greater than 60, the viscosity of the paint is significantly higher. Thus, the filling property tends to decrease. On the other hand, when the average aspect ratio is less than 2, the influence of the demagnetizing field increases, and the electromagnetic wave absorption characteristics tend to decrease. Furthermore, when the average particle diameter (major axis) is smaller than 10 μm, the average aspect ratio is larger than 60, and as in the case, the viscosity becomes remarkably high and the filling property tends to decrease. If the average particle diameter exceeds lmm, it becomes difficult to form a thin sheet even if the aspect ratio is large.
軟磁性材料の平均粒子径の長径及び短径は、例えば、硬化体の切断面を走査型 電子顕微鏡で 200倍〜 2000倍の倍率で観察し、任意 100個の粒子につき、その切 断面に見られる粒子の長軸長さ及び短軸長さを画像解析装置 (例えば、日本アビォ -クス社製「SPICCA— 11」）を用いて測定し、それを平均することによってそれぞれ 求めることができる。  The major axis and minor axis of the average particle diameter of the soft magnetic material can be determined by, for example, observing the cut surface of the cured body with a scanning electron microscope at a magnification of 200 to 2000 times, and looking at an arbitrary 100 particles on the cross section. The major axis length and the minor axis length of the obtained particles can be measured by using an image analyzer (for example, “SPICCA-11” manufactured by Nippon Avivos Co., Ltd.) and averaged.
[0017] 本発明の電磁波吸収体では、前記有機系結合材 100体積部に対して、ホウ素固 溶カーボンブラックが好ましくは 0. 5〜 110体積部、特に好ましくは 4〜40体積部含 有され、また、軟磁性材料が好ましくは 60〜200体積部、特に好ましくは 80〜 150 体積部含有されるのが好適である。  In the electromagnetic wave absorber of the present invention, boron-soluble carbon black is preferably contained in an amount of 0.5 to 110 parts by volume, particularly preferably 4 to 40 parts by volume with respect to 100 parts by volume of the organic binder. The soft magnetic material is preferably contained in an amount of 60 to 200 parts by volume, particularly preferably 80 to 150 parts by volume.
また、ホウ素固溶カーボンブラックと軟磁性材料の配合割合は、軟磁性材料 100体 積部に対してホウ素固溶カーボンブラックが好ましくは 1〜： L000体積部、特に好まし くは 10〜： L00体積部含有することが好ましい。ホウ素固溶カーボンブラック 1体積部 未満では電磁波吸収特性の向上効果がみられず、 1000体積部を超えると充填性や 成形が難しくなる場合がある。  The mixing ratio of boron solid solution carbon black and soft magnetic material is preferably 1 to L000 volume part of boron solid solution carbon black with respect to 100 parts of soft magnetic material, particularly preferably 10 to L00. It is preferable to contain by volume. If it is less than 1 volume part of boron solid solution carbon black, the effect of improving electromagnetic wave absorption characteristics is not observed, and if it exceeds 1000 volume parts, filling properties and molding may be difficult.
[0018] 本発明の電磁波吸収体は、可燃性材料である有機系結合材ゃホウ素固溶カーボ ンブラックを使用しており、軟磁性材料にも可燃性のものがある。したがって、難燃性 が要求される場合には難燃剤を添加する必要がある。しかし、環境問題からハロゲン 系難燃剤の使用は好ましくなぐ本発明に使用する難燃層として用いられる難燃剤は 、ハロゲンを含まない、無機水酸ィ匕物やリンィ匕合物などが好ましい。これらの難燃剤 は、前記有機系結合材 100質量部に対して、好ましくは 2〜300質量部、特に好まし くは 5〜200質量部含有されるのが好適である。  The electromagnetic wave absorber of the present invention uses an organic binder, which is a combustible material, or boron solid solution carbon black, and some soft magnetic materials are combustible. Therefore, it is necessary to add a flame retardant when flame retardancy is required. However, it is not preferable to use a halogen-based flame retardant because of environmental problems. The flame retardant used as the flame retardant layer used in the present invention is preferably an inorganic hydroxide or phosphorus compound containing no halogen. These flame retardants are preferably contained in an amount of 2 to 300 parts by mass, particularly preferably 5 to 200 parts by mass with respect to 100 parts by mass of the organic binder.
[0019] 本発明に使用する上記無機水酸ィ匕物としては、特に限定されるものではないが、 水酸ィ匕アルミニウム、水酸ィ匕マグネシウムなどが挙げられる。無機水酸ィ匕物は、加熱 時に脱水反応による吸熱が生じ温度上昇が低減するため耐熱性が向上する。さらに 、加熱脱水後、酸ィ匕物が残りこれによつて強度が向上する点で好ましい。中でも水酸 化アルミニウムは、安価であり、難燃性付与効果が大きくさらに好ましい。 [0019] The inorganic hydroxide used in the present invention is not particularly limited, and examples thereof include hydroxide-aluminum and hydroxide-magnesium. Inorganic hydroxide is heated Sometimes heat is absorbed due to a dehydration reaction, and the temperature rise is reduced, thus improving heat resistance. Furthermore, after the heat dehydration, acid oxides remain, which is preferable in that the strength is improved. Among these, aluminum hydroxide is more preferable because it is inexpensive and has a large effect of imparting flame retardancy.
無機水酸ィ匕物は、難燃性を付与するために一般にハロゲン系難燃剤などに比べて 多くの添加量を必要とすることから、成形性や機械的物性などへの影響が懸念される 力 本発明の電磁波吸収体では、ホウ素固溶カーボンブラックを用いることでその影 響を小さく抑えることができる。  Inorganic hydroxides generally require a larger amount of addition than halogen-based flame retardants in order to impart flame retardancy, and there is concern about the impact on moldability and mechanical properties. Force In the electromagnetic wave absorber of the present invention, the influence can be suppressed small by using boron solid solution carbon black.
[0020] 本発明に使用する上記リンィ匕合物としては、特に限定されるものではないが、赤リン ；トリフエ二ノレホスフェート、トリクレジノレホスフェート、トリキシレニノレホスフェート、クレジ ルジフエ-ルホスフェート、キシレ -ルジフエ-ルホスフェートなどの各種リン酸エステ ル；リン酸ナトリウム、リン酸カリウム、リン酸マグネシウムなどのリン酸金属塩;ポリリン 酸アンモ-ゥム類などが挙げられる。中でも赤リンが好ましい。赤リンは少量の添加で 難燃性が向上するが、耐湿性、発火しない安全性の点で添加量は少なぐ赤リン粒 子の表面を榭脂でコーティングしたものが好ましい。  [0020] The phosphorus compound used in the present invention is not particularly limited, but includes red phosphorus; -Various phosphate esters such as diphenyl phosphate; metal phosphates such as sodium phosphate, potassium phosphate and magnesium phosphate; polyphosphate ammonia. Of these, red phosphorus is preferred. A small amount of red phosphorus improves the flame retardancy, but in terms of moisture resistance and safety against ignition, the amount of red phosphorus is small.
[0021] さらに、本発明では、無機水酸ィ匕物にリンィ匕合物を併用することにより、少量の添加 量で難燃性を向上させることができる。  [0021] Furthermore, in the present invention, flame retardance can be improved with a small amount of addition by using a phosphorus compound in combination with an inorganic hydroxide compound.
[0022] 有機系結合材、軟磁性材料、ホウ素固溶カーボン粉末、及び難燃剤などの混合は 、少量の場合は手混合も可能である力 プラネタリーミキサー、ハイブリッドミキサー、 ヘンシェルミキサー、ニーダー、ボールミル、ミキシングロールなどの一般的な混合機 を使用することができる。  [0022] Mixing of organic binder, soft magnetic material, boron solid solution carbon powder, flame retardant, etc. is a force that can be manually mixed in small amounts Planetary mixer, hybrid mixer, Henschel mixer, kneader, ball mill In addition, a general mixer such as a mixing roll can be used.
[0023] 本発明の電磁波吸収体の形状は、特に限定されるものではないが、シート形状な どの薄型成形体が主であり、その加工方法としては従来公知の方法、例えば、ドクタ 一ブレード法、押出成形法、ロール成形法、射出成形法、プレス成形法などの各種 成形法を使用することができる。  [0023] The shape of the electromagnetic wave absorber of the present invention is not particularly limited, but is mainly a thin molded body such as a sheet shape, and the processing method thereof is a conventionally known method such as a doctor-blade method. Various molding methods such as extrusion molding, roll molding, injection molding and press molding can be used.
[0024] 本発明におけるシート形状の電磁波吸収体は、ホウ素固溶カーボンブラックを用い ることで軟磁性材料との複合系でありながら強度低下が比較的小さいため、適当な ノインダー榭脂を用いることにより単層でも強度を得ることは可能である。さらに、シ ートの電子機器への実装時における作業性を改善するためポリエチレンテレフタレ ート (PET)やポリイミドなどの高強度基材の薄膜シートと複合ィ匕することがより好まし い。 [0024] Since the sheet-shaped electromagnetic wave absorber in the present invention is a composite system with a soft magnetic material by using boron solid solution carbon black, the strength decrease is relatively small. Thus, it is possible to obtain strength even with a single layer. In addition, polyethylene terephthalate is used to improve workability when mounting sheets on electronic equipment. More preferably, it is combined with a thin film sheet of a high-strength substrate such as PET (polyester) or polyimide.
[0025] 高強度基材の厚さは、薄すぎると強度補強効果が少なぐ厚すぎると電磁波吸収体 のトータルの厚みが大きくなつて好ましくない。厚さは、 1〜50 /ζ πιの範囲が好ましい  [0025] If the thickness of the high-strength base material is too thin, the strength reinforcing effect is too small. If the thickness is too thick, the total thickness of the electromagnetic wave absorber is undesirably large. The thickness is preferably in the range of 1-50 / ζ πι
[0026] 複合化の方法としては、例えば、高強度基材の薄膜シート上に有機系結合材と軟 磁性材料、ホウ素固溶カーボンブラック、さらに難燃剤などを溶媒中に溶解させた塗 料をドクターブレードなどにて塗布し、溶媒を揮発させることにより製膜することが可 能である。 [0026] As a method for compounding, for example, a coating in which an organic binder, a soft magnetic material, boron solid solution carbon black, and a flame retardant are dissolved in a solvent on a thin film sheet of a high-strength substrate is used. It is possible to form a film by applying it with a doctor blade and evaporating the solvent.
また、予め作製した有機系結合材と軟磁性材料、ホウ素固溶カーボンブラック、さら に、難燃剤などカゝらなるシート形状の電磁波吸収体に粘着層を介して高強度基材の 薄膜シートを積層することが可能である。  In addition, an organic binder and soft magnetic material prepared in advance, boron solid solution carbon black, and a sheet-shaped electromagnetic wave absorber such as a flame retardant are attached to a thin film sheet of a high-strength substrate via an adhesive layer. It is possible to laminate.
[0027] シート形状の電磁波吸収体は、電子機器への実装を考慮しそのいずれか一方の 面に粘着層を設けてもよい。また、高強度基材の薄膜シートと複合ィ匕したものについ ても同様である。粘着層は粘着剤のみカゝらなるもの、及び基材を有するものであって ちょい。 [0027] The sheet-shaped electromagnetic wave absorber may be provided with an adhesive layer on one surface thereof in consideration of mounting on an electronic device. The same applies to a composite sheet of a high-strength base material thin film sheet. The pressure-sensitive adhesive layer is composed of only a pressure-sensitive adhesive and has a base material.
[0028] 本発明におけるシート形状の電磁波吸収層と高強度基材の薄膜シートや粘着層と の積層には、ラミネート法など任意の公知手法が用いられる。  In the present invention, any known method such as a laminating method is used for laminating the sheet-shaped electromagnetic wave absorbing layer and the thin film sheet or adhesive layer of the high-strength substrate.
[0029] 以下、実施例により、本発明を詳細に説明する。 [0029] Hereinafter, the present invention will be described in detail by way of examples.
実施例  Example
[0030] 表 1に示した量のトルエンにアクリルゴム（日本ゼオン社製、 Nipol AR53L)を溶 解させアクリルゴム溶液を作製した。  [0030] An acrylic rubber solution was prepared by dissolving acrylic rubber (Nipol AR53L, manufactured by Nippon Zeon Co., Ltd.) in the amount of toluene shown in Table 1.
該アクリルゴム溶液に対して、アセチレンブラック（電気化学工業社製)あるいはホウ 素固溶アセチレンブラック (電気化学工業社製、ホウ素量 0. 82%、 JIS K 1469に よる電気抵抗率 0. 08 Ω cm)、金属軟磁性粉 (三菱マテリアル社製、 JEM粉、平均粒 子アスペクト比 a : 20、 b : l . 5、 c : 7、 d : 47、平均粒子径（長径） a : 24 m、 1> : 18 /ζ πι 、 c:20 ^ m, ά: 120 μ mの 4種類）、水酸化アルミニウム（昭和電工社製ハイジライト H 32、平均粒径 8 m)及び Z又は赤リン（日本化学工業社製ヒシガード)を、表 1に 示す所定の割合となるように添加し、ハイブリッドミキサー（キーエンス社製、 HM- 5 00)を用いて混合し、スラリーを作製した (実施例 1〜10、比較例 1〜5)。 For the acrylic rubber solution, acetylene black (manufactured by Denki Kagaku Kogyo) or boron solid solution acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd., boron content 0.82%, electrical resistivity according to JIS K 1469 0.08 Ω cm), metal soft magnetic powder (Mitsubishi Materials, JEM powder, average particle aspect ratio a: 20, b: l .5, c: 7, d: 47, average particle diameter (major axis) a: 24 m, 1>: 18 / ζ πι, c: 20 ^ m, ά: 120 μm, aluminum hydroxide (Showa Denko Hygielite H 32, average particle size 8 m) and Z or red phosphorus (Japan) Chemical industry Hishiguard) is shown in Table 1. It added so that it might become the predetermined | prescribed ratio shown, and it mixed using the hybrid mixer (the Keyence company make, HM-500), and produced the slurry (Examples 1-10, Comparative Examples 1-5).
[0031] 同様に、表 1に記載した量のトルエンにアクリルゴム（日本ゼオン社製、 Nipol AR 53L)を溶解させアクリルゴム溶液を作製した。該アクリルゴム溶液に対して、ケッチェ ンブラック (三菱ィ匕学社製、ケッチェンブラック EC)、あるいは黒鉛粉 (エス'ィー 'シー 社製、 SGP100)、軟磁性材料 (三菱マテリアル社製、 JEM粉)を、表 1に示す所定の 割合となるように添加し、テーブルミキサーを用いて混合し、スラリーを作製した (比較 例 6、 7)。 Similarly, an acrylic rubber solution was prepared by dissolving acrylic rubber (Nipol AR 53L, manufactured by Nippon Zeon Co., Ltd.) in the amount of toluene described in Table 1. For this acrylic rubber solution, Ketchen Black (manufactured by Mitsubishi Chemical Co., Ltd., Ketjen Black EC), or graphite powder (SGC Corporation, SGP100), soft magnetic material (manufactured by Mitsubishi Materials Corporation, JEM powder) was added so as to have a predetermined ratio shown in Table 1, and mixed using a table mixer to prepare a slurry (Comparative Examples 6 and 7).
[0032] 実施例 1〜10及び比較例 1〜7、の各スラリーをドクターブレード法にて、厚さ 10 mの PET基材 (三菱榭脂社製)上に粘着層を介して塗膜を作製し、前記塗膜を 70°C に加熱し溶媒を揮発させることで、厚さ 100 /z mのシート状成形体を得た。なお、 PE T基材の片面に粘着剤溶液 (綜研化学社製 1717)をドクターブレード法により、所 定の厚さの塗膜を作製し、該塗膜を 70°Cに加熱し溶媒を揮発させ、厚さ 20 mの粘 着層を形成し、粘着剤付き PET基材を作製した。  [0032] Each of the slurries of Examples 1 to 10 and Comparative Examples 1 to 7 was coated by a doctor blade method on a 10 m-thick PET substrate (manufactured by Mitsubishi Oil Co., Ltd.) via an adhesive layer. The sheet was formed and heated to 70 ° C. to evaporate the solvent, thereby obtaining a sheet-like molded body having a thickness of 100 / zm. In addition, an adhesive solution (1717, manufactured by Soken Chemical Co., Ltd.) was prepared on one side of the PET substrate by the doctor blade method, and the coating film was heated to 70 ° C to volatilize the solvent. An adhesive layer with a thickness of 20 m was formed to produce a PET substrate with an adhesive.
[0033] なお、使用したホウ素固溶アセチレンブラックのホウ素固溶量については、以下に 従って測定し、全ホウ素量力も可溶ホウ素量を差し引くことによって求めた。全ホウ素 量は、ホウ素固溶アセチレンブラック 0. 5gを白金皿に採り、 1. 5%の水酸化カルシ ゥム水溶液 20ml、アセトン 5mlを加え、 1時間超音波分散させた後、乾固し、酸素気 流中 800°Cで 3時間かけて灰化し、その後塩酸中に加熱溶出させ、 ICP—AESでホ ゥ素を定量することにより測定した。  [0033] The boron solid solution amount of the boron solid solution acetylene black used was measured according to the following, and the total boron amount was also determined by subtracting the soluble boron amount. The total amount of boron is 0.5g boron solid solution acetylene black in a platinum dish, add 20ml of 1.5% calcium hydroxide aqueous solution and 5ml acetone, and ultrasonically disperse for 1 hour. It was measured by ashing at 800 ° C for 3 hours in an oxygen stream, then heating and eluting in hydrochloric acid, and quantifying fluorine with ICP-AES.
また、比表面積は窒素ガス吸着による BET式 1点法にて測定した。  The specific surface area was measured by the BET one-point method using nitrogen gas adsorption.
[0034] 得られたシート状成形体の表面状態を下記の基準にて 3段階に評価した。  [0034] The surface state of the obtained sheet-like molded product was evaluated in three stages according to the following criteria.
〇：シートの表面が平滑であり厚さ斑がほとんどな 、もの。  ◯: The sheet has a smooth surface and almost no thickness spots.
X：シートの厚さ斑が激しく割れがあり、使用上の問題があるもの。あるいは塗料の 流動性が悪ぐシートィ匕できな力つたもの。  X: Thickness spots on the sheet are severely cracked, causing problems in use. Or the power of a sheet that has poor fluidity.
[0035] (電磁波吸収特性） [0035] (Electromagnetic wave absorption characteristics)
得られたシート状成形体に対し、ネットワークアナライザ (8517D、アジレントテクノ ロジ一社製)を使用して、 0. l〜3GHzの周波数に対し電磁波吸収特性を測定した。 吸収特性は、マイクロストリップライン法を用いて、ライン上の電磁波の吸収測定結果 より評価した。 2GHzにおける伝送損失 (S21)の結果を表 1に示した。 Using the network analyzer (8517D, manufactured by Agilent Technologies, Inc.), electromagnetic wave absorption characteristics were measured for the obtained sheet-like molded product at frequencies of 0.1 to 3 GHz. Absorption characteristics were evaluated from the results of absorption measurements of electromagnetic waves on the line using the microstrip line method. Table 1 shows the results of transmission loss (S21) at 2 GHz.
[0036] 一般に、伝送損失 (S21)が小さい (絶対値が大きい)ほど、吸収特性が良いとされる 。表 1に示したように、実施例 1〜4は、ホウ素固溶アセチレンブラック非添加の比較 例 1と比較して吸収特性が良好であった。また、表 1から、ホウ素固溶アセチレンブラ ックの含有量が多 、ほど、伝送損失 (S21)の絶対値が大きくなつて 、ることが判る。 さらに、難燃剤を添加した実施例 5〜7は、難燃性が高いことが判る。 [0036] Generally, the smaller the transmission loss (S21) (the larger the absolute value), the better the absorption characteristics. As shown in Table 1, Examples 1 to 4 had better absorption characteristics than Comparative Example 1 in which no boron solid solution acetylene black was added. Table 1 also shows that the absolute value of the transmission loss (S21) increases as the content of boron solid solution acetylene black increases. Furthermore, it turns out that Examples 5-7 which added the flame retardant have high flame retardance.
[0037] 実施例 8〜： LOは、磁性粉の種類を変えて作製したシートの吸収特性などを比較し たものである。実施例 1も含め、ホウ素固溶アセチレンブラックと磁性粉の複合系では 、磁性粉単独系（比較例 1〜4)と比較して、非常に高い吸収特性が得られているが、 特にアスペクト比の大きい磁性粉を用いた場合 (実施例 10)において、その相乗効 果が顕著になって 、ることが判る。 [0037] Example 8-: LO is a comparison of the absorption characteristics and the like of sheets prepared by changing the type of magnetic powder. In the composite system of boron solid solution acetylene black and magnetic powder including Example 1, very high absorption characteristics are obtained compared to the magnetic powder alone system (Comparative Examples 1 to 4). It can be seen that in the case of using a magnetic powder having a large size (Example 10), the synergistic effect becomes remarkable.
[0038] 比較例 5は、ホウ素を固溶していない通常のアセチレンブラックを使用し、性能を比 較したものである。表 1に示したように、実施例 4と同一の部数を充填し塗料ィ匕したが 、作製したシートの状態は不良であり、測定した電磁波吸収特性も実施例 4に比べて 低い。 [0038] Comparative Example 5 uses ordinary acetylene black in which boron is not dissolved in solid, and compares the performance. As shown in Table 1, the same number of parts as in Example 4 were filled and painted, but the state of the produced sheet was poor and the measured electromagnetic wave absorption characteristics were also lower than in Example 4.
[0039] 比較例 6は、比表面積が大き 、ケッチェンブラックを使用し、性能を比較したもので ある。表 1に示したように、実施例 1と同一の部数を充填し塗料ィ匕するために多量のト ルェンを添加して試みた力 スラリーへの混合が不十分で、均一な塗工ができなかつ た。  [0039] Comparative Example 6 uses a ketjen black having a large specific surface area and compares the performance. As shown in Table 1, the same amount of parts as in Example 1 was tried to add a large amount of toluene to fill the paint. Mixing into the slurry was insufficient and uniform coating was possible. Natsuki.
[0040] 比較例 7は、比表面積が小さい黒鉛粉を使用し、性能を比較したものである。表 1 に示したように、実施例 1と同一の部数を充填し塗料ィ匕した力 作製したシートの厚 みむらが大きく状態不良であり、測定した電磁波吸収特性も低い。  [0040] Comparative Example 7 uses graphite powder having a small specific surface area and compares the performance. As shown in Table 1, the force of filling the same number of parts as in Example 1 and applying the paint was as follows. The thickness unevenness of the produced sheet was large and the condition was poor, and the measured electromagnetic wave absorption characteristics were also low.
[0041] [表 1] 表 1 [0041] [Table 1] table 1
Figure imgf000012_0001
Figure imgf000012_0001
[0042] (実施例 11) [Example 11]
実施例 1と同じ配合で作製したスラリーを、離型剤処理した PETフィルム上に塗布 した後に 70°Cで乾燥し、 PETから引き剥がしてシート状成形体とした。  A slurry prepared with the same composition as Example 1 was applied onto a PET film treated with a release agent, dried at 70 ° C., and peeled off from PET to obtain a sheet-like molded product.
[0043] (引張り強度） [0043] (Tensile strength)
実施例 1及び実施例 11のシートから、それぞれ 10mm幅にカットして短冊状サンプ ルを作製し、引張り強度を測定した。  Each of the sheets of Example 1 and Example 11 was cut to a width of 10 mm to produce a strip sample, and the tensile strength was measured.
その結果、実施例 1のシートの引張り強度は 16MPa、実施例 11の PETフィルムを 引き剥がしたシートは 0. 6MPaであった。  As a result, the tensile strength of the sheet of Example 1 was 16 MPa, and the sheet from which the PET film of Example 11 was peeled was 0.6 MPa.
[0044] (実施例 12) [0044] (Example 12)
実施例 1と同じ配合で作製したスラリーを、粘着層を介さずに厚さ 10 mの PET基 材上に塗布し、所定の厚さの塗膜を作製した。前記塗膜を 70°Cに加熱し溶媒を揮発 させ、シート状成形体とした。  A slurry prepared with the same composition as in Example 1 was applied on a PET base material having a thickness of 10 m without using an adhesive layer to prepare a coating film having a predetermined thickness. The coating film was heated to 70 ° C. to evaporate the solvent, thereby obtaining a sheet-like molded body.
[0045] (シート剥離性） [0045] (Sheet peelability)
実施例 1及び実施例 12のシートから、それぞれ 10mm幅にカットして短冊状サンプ ルを作製し、 PET基材と電磁波吸収シートの剥離を試みた。  Each of the sheets of Example 1 and Example 12 was cut to a width of 10 mm to produce a strip sample, and an attempt was made to peel off the PET substrate and the electromagnetic wave absorbing sheet.
その結果、粘着層の無い実施例 12のシートは剥離した。  As a result, the sheet of Example 12 without the adhesive layer was peeled off.
産業上の利用可能性  Industrial applicability
[0046] 本発明の電磁波吸収体は、電磁波吸収特性に優れ、しかも厚みが薄ぐ軽ぐかつ 、生産性に優れているなどの効果を奏し、デジタルカメラなどの小型携帯機器などに 幅広く使用することができる。 なお、 2005年 3月 7日に出願された日本特許出願 2005— 062284号の明細書、 特許請求の範囲、及び要約書の全内容をここに引用し、本発明の明細書の開示とし て、取り入れるものである。 [0046] The electromagnetic wave absorber of the present invention is excellent in electromagnetic wave absorption characteristics, is thin and light and has excellent productivity, and is widely used in small portable devices such as digital cameras. be able to. The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2005-062284 filed on March 7, 2005 are cited herein as the disclosure of the specification of the present invention. Incorporated.

Claims

請求の範囲  The scope of the claims
[I] 有機系結合材中にホウ素固溶カーボンブラックと軟磁性材料とを含有することを特 徴とする電磁波吸収体。  [I] An electromagnetic wave absorber characterized by containing a boron solid solution carbon black and a soft magnetic material in an organic binder.
[2] ホウ素固溶カーボンブラック力JIS K 1469による電気抵抗率が 0. l Q cm以下で ある請求項 1に記載の電磁波吸収体。  [2] The electromagnetic wave absorber according to claim 1, wherein the boron solid solution carbon black force has an electrical resistivity of 0.1 lQ cm or less according to JIS K 1469.
[3] 軟磁性材料の平均粒子アスペクト比が 2〜60、平均粒子径 (長径）が 10 μ m〜lm mである請求項 1又は 2に記載の電磁波吸収体。 [3] The electromagnetic wave absorber according to claim 1 or 2, wherein the soft magnetic material has an average particle aspect ratio of 2 to 60 and an average particle diameter (major axis) of 10 μm to lmm.
[4] 前記有機系結合材が、アクリル榭脂又はアクリルゴムである請求項 1〜3のいずれ かに記載の電磁波吸収体。 [4] The electromagnetic wave absorber according to any one of claims 1 to 3, wherein the organic binder is acrylic resin or acrylic rubber.
[5] 前記有機系結合材 100体積部に対して、ホウ素固溶カーボンブラックが 0. 5〜11[5] Boron solid solution carbon black is 0.5 to 11 per 100 parts by volume of the organic binder.
0体積部、軟磁性材料が 60〜200体積部含有される請求項 1〜4の 、ずれかに記載 の電磁波吸収体。 The electromagnetic wave absorber according to claim 1, wherein 0 part by volume and 60 to 200 parts by volume of a soft magnetic material are contained.
[6] 軟磁性材料 100体積部に対しホウ素固溶カーボンブラック 1〜： L000体積部含有す る請求項 1〜5のいずれかに記載の電磁波吸収体。  [6] The electromagnetic wave absorber according to any one of [1] to [5], which is contained in a volume of boron solid solution carbon black 1 to L000 with respect to 100 parts by volume of the soft magnetic material.
[7] さらに、難燃剤を含有する請求項 1〜6のいずれかに記載の電磁波吸収体。 7. The electromagnetic wave absorber according to any one of claims 1 to 6, further comprising a flame retardant.
[8] 前記難燃剤が無機水酸ィ匕物及び Z又はリンィ匕合物である請求項 7に記載の電磁 波吸収体。 8. The electromagnetic wave absorber according to claim 7, wherein the flame retardant is an inorganic hydroxide and a Z or phosphorus compound.
[9] 前記無機水酸ィ匕物が水酸ィ匕アルミニウム、リンィ匕合物が赤リンである請求項 8に記 載の電磁波吸収体。  9. The electromagnetic wave absorber according to claim 8, wherein the inorganic hydroxide is an aluminum hydroxide and the phosphorus compound is red phosphorus.
[10] 高強度基材と複合化した請求項 1〜9のいずれかに記載の電磁波吸収体。  [10] The electromagnetic wave absorber according to any one of claims 1 to 9, which is combined with a high-strength substrate.
[I I] 電磁波吸収体と高強度基材の中間に粘着層を有する請求項 10に記載の電磁波 吸収体。  [I I] The electromagnetic wave absorber according to claim 10, further comprising an adhesive layer between the electromagnetic wave absorber and the high-strength substrate.
[12] 請求項 1〜： L 1のいずれかに記載の電磁波吸収体を使用した電子機器。  [12] Claims 1 to: An electronic device using the electromagnetic wave absorber according to any one of L1.
PCT/JP2006/304124 2005-03-07 2006-03-03 Electromagnetic wave absorbing body WO2006095656A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2005062284A JP2006245472A (en) 2005-03-07 2005-03-07 Electromagnetic wave absorber
JP2005-062284 2005-03-07

Publications (1)

Publication Number Publication Date
WO2006095656A1 true WO2006095656A1 (en) 2006-09-14

Family

ID=36953255

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/304124 WO2006095656A1 (en) 2005-03-07 2006-03-03 Electromagnetic wave absorbing body

Country Status (2)

Country Link
JP (1) JP2006245472A (en)
WO (1) WO2006095656A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4849220B2 (en) * 2005-10-03 2012-01-11 戸田工業株式会社 Electromagnetic interference suppression sheet and manufacturing method thereof, flat cable for high-frequency signal, and flexible printed circuit board
WO2008087688A1 (en) * 2007-01-18 2008-07-24 Toda Kogyo Corporation Electroconductive and magnetic filler, resin composition comprising the electroconductive and magnetic filler, electromagnetic wave interference suppression sheet using the resin composition, use of the electromagnetic wave interference suppression sheet, and process for producing the electromagnetic wave interference suppr
JP4995596B2 (en) * 2007-02-21 2012-08-08 株式会社住化分析センター Quantitative determination of boron in graphite
CN101683020B (en) * 2007-04-11 2012-04-18 户田工业株式会社 Sheet for prevention of electromagnetic wave interference and method for production thereof
JP4824621B2 (en) * 2007-05-08 2011-11-30 興国インテック株式会社 Radio wave absorber composition, radio wave absorber, and method for producing radio wave absorber
JP5705460B2 (en) * 2010-05-26 2015-04-22 小松精練株式会社 Electromagnetic wave absorber, method for producing electromagnetic wave absorber, and electronic device
JP5879026B2 (en) * 2010-07-23 2016-03-08 Ｎｅｃトーキン株式会社 Flame retardant noise suppression sheet

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60249392A (en) * 1984-05-24 1985-12-10 ティーディーケイ株式会社 Electromagnetic shielding material
JP2000281933A (en) * 1999-03-29 2000-10-10 Denki Kagaku Kogyo Kk Carbon black and its preparation and electrically- conductive composition
JP2001244684A (en) * 2000-03-01 2001-09-07 Toyo Chem Co Ltd Magnetic body sheet
JP2004336028A (en) * 2003-04-18 2004-11-25 Nitta Ind Corp Electromagnetic wave absorbing material

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60249392A (en) * 1984-05-24 1985-12-10 ティーディーケイ株式会社 Electromagnetic shielding material
JP2000281933A (en) * 1999-03-29 2000-10-10 Denki Kagaku Kogyo Kk Carbon black and its preparation and electrically- conductive composition
JP2001244684A (en) * 2000-03-01 2001-09-07 Toyo Chem Co Ltd Magnetic body sheet
JP2004336028A (en) * 2003-04-18 2004-11-25 Nitta Ind Corp Electromagnetic wave absorbing material

Also Published As

Publication number Publication date
JP2006245472A (en) 2006-09-14

Similar Documents

Publication Publication Date Title
CN109155183B (en) Wireless power transmission device for vehicle
WO2006095656A1 (en) Electromagnetic wave absorbing body
WO2017145869A1 (en) Hexagonal boron nitride powder, production method therefor, resin composition and resin sheet
WO2005101941A1 (en) Electromagnetic wave absorber
JP4849220B2 (en) Electromagnetic interference suppression sheet and manufacturing method thereof, flat cable for high-frequency signal, and flexible printed circuit board
US9380736B2 (en) Electromagnetic interference suppressor
US20090114440A1 (en) Conductive Magnetic Filler, Resin Composition Containing the Filler, Electromagnetic Interference Suppressing Sheet Using the Resin Composition and Applications Thereof, and Process for Producing the Electromagnetic Interference Suppressing Sheet
WO2004086837A1 (en) Electromagnetic noise suppressor, article with electromagnetic noise suppression function, and their manufacturing methods
JP2006032929A5 (en)
JP2006307209A (en) Sheet product, laminated product, product equipped with sheet and method for manufacturing sheet
JP2006032929A (en) Electromagnetic interference inhibitor, method of reducing electromagnetic interference empolying it, and rf-id device
JPWO2005081609A1 (en) Electromagnetic wave noise suppression body, electromagnetic wave noise suppression function-equipped structure, and manufacturing method thereof
JP2006128649A (en) Electromagnetic compatibility suppressor and method of manufacturing the same
TWI651262B (en) Hexagonal boron nitride powder, a method for producing the same, a resin composition, and a resin sheet
JP2009088237A (en) Electromagnetic interference suppressor and electromagnetic interference suppressing method using the same
WO2014098065A1 (en) Electromagnetic interference suppression body
JP2006037078A (en) Flame-retardant magnetic sheet
WO2016088826A1 (en) Composite-type electromagnetic wave suppression body
JP2004336028A (en) Electromagnetic wave absorbing material
JP2009155554A (en) Resin composition
WO2012081369A1 (en) Electromagnetic noise suppressing body, use of same, and electronic device
JP4611700B2 (en) Electromagnetic wave noise suppression sheet and method of using the same
JP2000244167A (en) Electromagnetic-wave-disturbance preventive material
JP4611699B2 (en) Conductive noise suppressor and conductive noise countermeasure method
JP2006060013A (en) Electromagnetic wave absorber

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

NENP Non-entry into the national phase

Ref country code: RU

122 Ep: pct application non-entry in european phase

Ref document number: 06715207

Country of ref document: EP

Kind code of ref document: A1