Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G49/00—Compounds of iron
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/04—Ingredients treated with organic substances
  • C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
  • C08L101/12—Compositions of unspecified macromolecular compounds characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity
• • 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
  • H01F1/032—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 hard-magnetic materials
  • H01F1/10—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 hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure
  • H01F1/11—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 hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles
  • H01F1/113—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 hard-magnetic materials non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles 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
• • 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

Definitions

• the vinyl resin can be one or more resins selected from the group consisting of acrylic resins and styrene resins.
• Al salt aluminum hexahydrate [AlCl 3 ⁇ 6H 2 O] chloride, aluminum nitrate nonahydrate [Al (NO 3) 3 ⁇ 9H 2 O ] and the like.
• the salt of the A atom can be one or more selected from the group consisting of Sr salt, Ba salt, Ca salt and Pb salt.
• Sr salt strontium chloride hexahydrate [SrCl 2 ⁇ 6H 2 O], strontium nitrate [Sr (NO 3) 2], strontium acetate hemihydrate [Sr (CH 3 COO) 2 -0.5H 2 O] and the like.
• the raw material aqueous solution and the alkaline aqueous solution may be simply mixed.
• the total amount of the raw material aqueous solution and the alkaline aqueous solution may be mixed at once, or the raw material aqueous solution and the alkaline aqueous solution may be gradually mixed. Further, it may be mixed while gradually adding the other to either the raw material aqueous solution or the alkaline aqueous solution.
• the method of mixing the raw material aqueous solution and the alkaline aqueous solution is not particularly limited, and examples thereof include a method of mixing by stirring.
• the stirring means is not particularly limited, and general stirring means can be used.
• m is 1 and X can represent a (meth) acryloyl group, an acrylamide group or an epoxy group.
• m is 2 or 3 and a plurality of Xs contained in the general formula 2 can independently represent a (meth) acryloyl group, an acrylamide group, or an epoxy group.
• the radio wave absorbing composition and the radio wave absorber include, as magnetic powder, a powder of a substituted hexagonal ferrite surface-treated with the surface treatment agent described above.
• the filling rate of the powder of the substituted hexagonal ferrite surface-treated with the surface treatment agent is not particularly limited.
• the filling rate can be 35% by volume or less as the volume filling rate, and can also be in the range of 15 to 35% by volume.
• the volume filling rate can be 35% by volume or more.
• the volume filling factor can be, for example, in the range of 35 to 60% by volume, preferably in the range of 35 to 50% by volume.
• (anhydrous) indicates an ⁇ , ⁇ -unsaturated dicarboxylic acid anhydride or an ⁇ , ⁇ -unsaturated dicarboxylic acid.
• ⁇ , ⁇ -unsaturated dicarboxylic acid anhydride or ⁇ , ⁇ -unsaturated dicarboxylic acid is preferable, and ⁇ , ⁇ -unsaturated dicarboxylic acid anhydride is more preferable.
• These ⁇ , ⁇ -unsaturated dicarboxylic acid components may be used alone or in combination of two or more in any combination and in any ratio.
• the method for producing the radio wave absorber a method of molding the radio wave absorbing composition into a desired shape by a known molding method as exemplified above can be mentioned. Further, as another form of the method for manufacturing the radio wave absorber, a method of applying the radio wave absorbing composition to the support and manufacturing the radio wave absorber as the radio wave absorbing layer can be mentioned.
• the support used here may be removed before the radio wave absorber is incorporated into the article to which the radio wave absorber should be imparted, or may be incorporated into the article together with the radio wave absorber without being removed.
• the in-vehicle radar which has been attracting attention in recent years, is a radar that uses radio waves in the millimeter wave frequency band.
• Millimeter waves are electromagnetic waves with a frequency of 30 GHz to 300 GHz.
• the radio wave absorber preferably exhibits a transmission attenuation amount and a reflection attenuation amount in the above range with respect to the frequency of the radio wave, that is, one or more frequencies in the frequency band of 3 terahertz (THz) or less.
• the radio wave absorber a metal layer may be laminated on a surface (so-called back surface) opposite to the surface on which the radio wave is incident on the radio wave absorber.
• a radio wave absorber is called a matched radio wave absorber.
• the reflection attenuation characteristic can be enhanced by providing a metal layer and utilizing the phase difference absorption.
• the radio wave absorber itself can have excellent reflection attenuation characteristics. Specifically, in one form, the radio wave absorber can exhibit a high amount of reflection attenuation regardless of the metal layer.
• composition of the magnetic material constituting each of the above magnetic powders was confirmed by high-frequency inductively coupled plasma emission spectroscopy. Specifically, it was confirmed by the following method.
• a container beaker containing 12 mg of magnetic powder and 10 mL of a hydrochloric acid aqueous solution having a concentration of 4 mol / L was held on a hot plate at a set temperature of 120 ° C. for 3 hours to obtain a solution. After adding 30 mL of pure water to the obtained solution, the mixture was filtered using a membrane filter having a filter pore size of 0.1 ⁇ m.
• the prepared composition was applied onto a glass plate (support) using an applicator to form a coating film of the above composition.
• the formed coating film was dried in an oven having an internal atmospheric temperature of 80 ° C. for 2 hours, and then the sheet sample (thickness: 0.3 mm) was peeled off from the glass plate.
• a vector network analyzer product name: N5225B
• a horn antenna product name: RH12S23
• the incident angle was set to 0 ° by the free space method.
• the S parameter was measured with the sweep frequency set to 60 GHz to 90 GHz.
• the peak frequency of the magnetic permeability ⁇ ′′ of the imaginary part was calculated from this S parameter using the Nicholson loss model method, and this peak frequency was used as the resonance frequency. The results are shown in Table 1.
• the obtained lumpy kneaded product was press-molded using a heating press machine (heating temperature: 210 ° C., press time: 1 minute, pressure: 20 MPa), length 10.0 cm ⁇ width 10.0 cm ⁇ thickness 2.0 mm.
• a radio wave absorber (radio wave absorption sheet) was prepared.
• the retention rate of the transmission attenuation is 95% or more
• One aspect of the present invention is useful in the technical field of performing various automatic driving controls such as automatic driving control of automobiles.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Medicinal Chemistry (AREA)
• Power Engineering (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Polymers & Plastics (AREA)
• Inorganic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Hard Magnetic Materials (AREA)
• Magnetic Record Carriers (AREA)

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Cited By (1)

Citations (4)

• 2020
  • 2020-08-03 WO PCT/JP2020/029624 patent/WO2021029247A1/ja not_active Ceased
  • 2020-08-03 JP JP2021539212A patent/JPWO2021029247A1/ja active Pending

Patent Citations (4)

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