WO2012147833A1 - 強磁性粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 - Google Patents
強磁性粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 Download PDFInfo
- Publication number
- WO2012147833A1 WO2012147833A1 PCT/JP2012/061176 JP2012061176W WO2012147833A1 WO 2012147833 A1 WO2012147833 A1 WO 2012147833A1 JP 2012061176 W JP2012061176 W JP 2012061176W WO 2012147833 A1 WO2012147833 A1 WO 2012147833A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- particle powder
- ferromagnetic
- magnet
- powder
- axis length
- Prior art date
Links
Classifications
-
- 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
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
- C01B21/0615—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with transition metals other than titanium, zirconium or hafnium
- C01B21/0622—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with transition metals other than titanium, zirconium or hafnium with iron, cobalt or nickel
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- H01F1/04—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 metals or alloys
- H01F1/06—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 metals or alloys in the form of particles, e.g. powder
- H01F1/065—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 metals or alloys in the form of particles, e.g. powder obtained by a reduction
-
- 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
- H01F1/04—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 metals or alloys
- H01F1/06—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 metals or alloys in the form of particles, e.g. powder
- H01F1/08—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 metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
- H01F1/083—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 metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together 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
- H01F1/14—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
- H01F1/22—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 pressed, sintered, or bound together
- H01F1/24—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 pressed, sintered, or bound together the particles being insulated
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/20—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds
- B22F9/22—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from solid metal compounds using gaseous reductors
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/54—Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/42—Magnetic properties
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C2202/00—Physical properties
- C22C2202/02—Magnetic
Definitions
- the present invention relates to a method for producing high-purity ferromagnetic particle powder in which a particle core is Fe 16 N 2 and an outer shell is covered with an oxide film made of very thin FeO.
- a anisotropic magnet, a bond magnet, and a dust magnet using the ferromagnetic particle powder are provided.
- Nd—Fe—B based magnetic powders and compacts are used as magnets for motors that require power and torque, such as hybrid vehicles, electric vehicles, home appliances such as air conditioners and washing machines.
- the theoretical limit as a magnet as an Nd—Fe—B magnet material is imminent.
- ⁇ ′′ -Fe 16 N 2 is known as a metastable compound that crystallizes when martensite or ferrite that dissolves nitrogen is annealed for a long time.
- This ⁇ ′′ -Fe 16 The crystal of N 2 has a bct structure and is expected as a giant magnetic substance having a large saturation magnetization.
- metastable compound there are very few reports of chemically synthesizing this compound as an isolated powder, so-called metastable compound.
- JP 11-340023 A JP 2000-277311 A JP 2009-84115 A JP 2008-108943 A JP 2008-103510 A JP 2007-335592 A JP 2007-258427 A JP 2007-134614 A JP 2007-36027 A JP 2009-249682 A
- Patent Documents 1 to 11 and Non-Patent Documents 1 and 2 are still not sufficient.
- Patent Document 1 describes that iron particles having a surface oxide film are reduced and then nitrided to obtain Fe 16 N 2. However, increasing the maximum energy product is considered. Not. Further, the nitriding reaction takes a long time, and it is difficult to say that it is industrial.
- Patent Document 2 describes that iron oxide powder is reduced to produce metallic iron powder, and the obtained metallic iron powder is nitrided to obtain Fe 16 N 2. It is used as a magnetic particle powder for a medium, and is hardly suitable as a hard magnetic material so as to have a high maximum energy product BH max .
- Patent Documents 3 to 9 although described as a maximal magnetic substance for a magnetic recording material instead of ferrite, an ⁇ ′′ -Fe 16 N 2 single phase has not been obtained, and a more stable ⁇ ′-Fe 4 N, ⁇ -Fe 2 to 3 N, martensite ( ⁇ ′-Fe), and ferrite ( ⁇ -Fe) -like metals are generated as mixed phases.
- Patent Document 10 although the additive element is essential, the necessity thereof is not discussed in detail, and the magnetic properties of the product obtained are hard magnetic materials so as to have a high maximum energy product BH max. It is difficult to say that it is preferable.
- Non-Patent Documents 1 and 2 have succeeded in obtaining an ⁇ ′′ -Fe 16 N 2 single phase in a thin film, but the thin film has limited application and is not suitable for wider application development. In addition, there are problems in productivity and economy when using a general-purpose magnetic material.
- a method for producing Fe 16 N 2 ferromagnetic particle powder covered with high purity and very thin FeO, an anisotropic magnet, a bond magnet, and a dust magnet using the obtained ferromagnetic particle powder The purpose is to provide.
- the present invention provides a method for producing a ferromagnetic particle powder in which an iron compound particle powder is reduced at 160 to 420 ° C. and then nitrided at 130 to 170 ° C.
- the major axis length is 40 to 5000 nm
- the aspect ratio (major axis diameter / minor axis diameter) is 1 to 200
- (average deviation of particle major axis length) / (average grain major axis length) is 50% or less.
- uniformity coefficient (U C) is 1.55 or less
- the curvature coefficient (C g) is 0.95 or more
- the iron compound particles extensive curvature coefficient (C g 2) is 0.40 or more Is a method for producing a ferromagnetic particle powder (Invention 1).
- the present invention is a method for producing a ferromagnetic particle powder according to the first aspect of the present invention, wherein the iron compound particle powder is at least one selected from magnetite, hematite and goethite (Invention 2).
- the present invention is the method for producing a ferromagnetic particle powder according to the present invention 1 or 2, wherein the obtained ferromagnetic particles have FeO in the particle outer shell and the film thickness of FeO is 5 nm or less (the present invention). 3).
- the present invention provides the method for producing a ferromagnetic particle powder according to any one of the present inventions 1 to 3, wherein the obtained ferromagnetic particle powder has a FeO volume fraction of 25% or less in terms of FeO volume / total particle volume. (Invention 4).
- the present invention provides the ferromagnetic particles according to any one of the present inventions 1 to 4, wherein the obtained ferromagnetic particle powder has a coercive force H C of 1.5 kOe or more and a saturation magnetization ⁇ S at 5 K of 150 emu / g or more.
- This is a method for producing particle powder (Invention 5).
- the present invention is the method for producing a ferromagnetic particle powder according to any one of the present inventions 1 to 5, wherein the nitriding rate calculated from the lattice constant of the obtained ferromagnetic particle powder is 8.0 to 13 mol%. (Invention 6).
- the present invention is a method for producing an anisotropic magnet comprising a step of obtaining a ferromagnetic particle powder by the production method according to any one of the present inventions 1 to 6 and a step of performing magnetic orientation (the present invention). 7).
- the present invention also includes a step of obtaining a ferromagnetic particle powder by the production method according to any one of the present inventions 1 to 6, a step of dispersing the obtained ferromagnetic particle powder in a binder resin to obtain a mixture, A method of manufacturing a bonded magnet comprising a step of forming a mixture (Invention 8).
- the present invention also provides a dust magnet comprising a step of obtaining a ferromagnetic particle powder by the production method according to any one of the present inventions 1 to 6, and a step of compression-molding the obtained ferromagnetic particle powder in a magnetic field. (Invention 9).
- the method for producing ferromagnetic particle powder according to the present invention is suitable as a method for producing ferromagnetic particle powder because a highly pure and stable Fe 16 N 2 particle powder can be easily obtained.
- a uniformity coefficient (U C) is 1.55 or less
- Curvature coefficient (C g ) is 0.95 or more
- wide range curvature coefficient (C g 2) is 0.40 or more
- average particle major axis length is 40 to 5000 nm
- aspect ratio (major axis diameter / minor axis diameter) ) Is used as a starting material, and the iron compound particle powder is reduced at 160 to 420 ° C. and nitrided at 130 to 170 ° C. Can be obtained.
- the iron compound particle powder as a starting material is iron oxide or iron oxyhydroxide, and is not particularly limited, but magnetite (Fe 3 O 4 ), ⁇ -Fe 2 O 3 , hematite ( ⁇ -Fe 2 O 3 ), Examples include goethite ( ⁇ -FeOOH), ⁇ -FeOOH, ⁇ -FeOOH, and FeO.
- the starting material may be a single phase or may contain impurities, and the impurities may contain iron oxide or iron oxyhydroxide other than the main phase.
- the starting material for obtaining the ferromagnetic particle powder according to the present invention has (average particle major axis length deviation) / (average particle major axis length) of 50% or less.
- (average particle long axis length deviation) / (average particle long axis length) exceeds 50%, the volume fraction of the Fe 16 N 2 compound phase is less than 80% based on Mossbauer spectrum data.
- (average particle long axis length deviation) / (average particle long axis length) is 45% or less, more preferably (particle long axis length deviation average) / (average particle long axis length) is 40% or less.
- the particle major axis length represents the length of the longest particle among various shaped particles.
- the shape with high symmetry such as a sphere or a cube, it is set to one of the lengths.
- the lower limit of (average particle long axis length deviation) / (average particle long axis length) is usually 1%.
- uniformity coefficient (U C) is 1.55 or less. If the U C exceeds 1.55, Fe 16 N 2 compound phase Mössbauer spectrum data is less than 80%. Preferably, U C is 1.50 or less. Uniformity coefficient (U C) is more preferably 1.40 or less. The lower limit of the uniformity coefficient (U C) is usually 1.
- the starting material for obtaining the ferromagnetic particle powder according to the present invention has a curvature coefficient (C g ) of 0.95 or more. If C g is less than 0.95, the volume fraction of the of the Fe 16 N 2 compound phase Mössbauer spectrum data is less than 80%. Preferably, it is C g is 0.96 or more.
- the upper limit of the curvature coefficient (C g ) is usually about 2.
- the starting material for obtaining the ferromagnetic particle powder according to the present invention has a wide range of curvature coefficient (C g 2) of 0.40 or more.
- C g 2 is less than 0.40, the volume fraction of the Fe 16 N 2 compound phase is less than 80% based on Mossbauer spectrum data.
- C g 2 is 0.50 or more, more preferably 0.70 or more.
- the upper limit of the wide range of curvature coefficient (C g 2) is usually about 2.
- uniformity coefficient of the (U C), for the method of determining the curvature coefficient (C g) and a wide range of curvature coefficient (C g 2), are described in the examples below.
- iron oxide or iron oxyhydroxide having an average particle major axis length of 40 to 5000 nm and an aspect ratio (major axis diameter / minor axis diameter) of 1 to 200 is used as a starting material. More preferably, the average particle major axis length is 45 to 4000 nm, and still more preferably 45 to 3000 nm.
- the particle shape of iron oxide or iron oxyhydroxide as a starting material is not particularly limited, but may be any of acicular, granular, spindle, rectangular parallelepiped, spherical, and the like.
- the aspect ratio (major axis diameter / minor axis diameter) of the iron compound particle powder in the present invention is 1.0 to 200. If it exceeds this range, it will be difficult to obtain a ferromagnetic particle powder comprising Fe 16 N 2 compound phase of 80% or more from the intended Mossbauer spectrum.
- a more preferred aspect ratio is 1.0 to 190, even more preferably 1.0 to 180.
- the BET specific surface area of the starting iron compound particle powder is preferably 20 to 250 m 2 / g.
- the BET specific surface area is less than 20 m 2 / g, nitriding is difficult to proceed, and it becomes difficult to obtain a ferromagnetic particle powder composed of 80% or more of the Fe 16 N 2 compound phase in the target Mossbauer spectrum.
- the BET specific surface area exceeds 250 m 2 / g, nitridation occurs excessively, so that it is difficult to obtain a ferromagnetic particle powder composed of 80% or more of the Fe 16 N 2 compound phase in the Mossbauer spectrum data.
- a more preferred BET specific surface area is 30 to 200 m 2 / g, and even more preferably 35 to 180 m 2 / g.
- the acicular goethite particles and spindle-shaped goethite particles in the present invention are ferrous hydroxide colloids obtained by reacting a ferrous salt aqueous solution with an alkali hydroxide, an alkali carbonate or an alkali hydroxide / alkali carbonate, iron carbonate, and It is obtained by a so-called wet method in which an oxygen-containing gas is passed through a suspension containing any of the iron-containing precipitates and oxidized.
- the acicular magnetite particles and spindle-shaped magnetite particles in the present invention can be obtained by heating and reducing the goethite particles at 250 to 500 ° C. in a reducing atmosphere.
- the magnetite particles in the present invention are oxidized by passing an oxygen-containing gas through a suspension containing ferrous hydroxide colloid obtained by reacting an aqueous ferrous salt solution with an alkali hydroxide. Is obtained.
- the magnetite particles in the present invention are obtained by a so-called wet method in which a ferrous salt aqueous solution, a ferric salt aqueous solution and an alkali hydroxide are reacted.
- the hematite particles in the present invention can be obtained by heating the magnetite particles produced by the wet method at 500 to 1000 ° C. in air.
- the hematite particles in the present invention can be obtained by heating the goethite particles produced by the wet method at 80 ° C. or higher in the air.
- an additive that controls the order of addition of raw materials and adjusts the reaction rate is allowed to coexist in the goethite formation reaction and magnetite formation reaction. It can be obtained by means such as adjusting the oxidation rate or adjusting the raw material concentration.
- the aggregate particle diameter of iron oxide or iron oxyhydroxide as a starting material is preferably controlled so that D50 is 40 ⁇ m or less and D90 is 150 ⁇ m or less. Since the starting material uses powder, the aggregated particle diameter is generally quite large.
- the method for reducing the aggregated particle size is not particularly limited. For example, ball mills, planetary ball mills, wet atomization, jet mills in the presence of alcohol compounds, ketone compounds, organic solvents such as toluene, hexane, carbon tetrachloride, and cyclohexane. It can be crushed. More preferably, D50 is 35 ⁇ m or less, D90 is 125 ⁇ m or less, and even more preferably, D50 is 30 ⁇ m or less, and D90 is 100 ⁇ m or less.
- the iron compound particle powder in the present invention is preferably passed through a mesh of 250 ⁇ m or less in advance before heat treatment.
- the mesh size exceeds 250 ⁇ m, it is difficult to obtain a ferromagnetic particle powder exhibiting desired magnetic properties. More preferably, it is 236 micrometers or less.
- the temperature of the dehydration treatment is preferably 80 to 350 ° C. Dehydration hardly proceeds below 80 ° C. When it exceeds 350 degreeC, it becomes difficult to obtain an iron metal particle powder at low temperature in the following reduction process. A more preferable dehydration temperature is 85 to 300 ° C.
- a pulverization process using a jet mill or a ball mill may be performed.
- an inert gas such as helium, argon, or nitrogen is preferably used.
- Dehydration is preferably performed in an air or nitrogen atmosphere.
- the reduction treatment temperature is 160-420 ° C.
- the reduction treatment temperature is less than 160 ° C.
- the iron compound particle powder is not sufficiently reduced to metallic iron.
- the reduction treatment temperature exceeds 420 ° C. the iron compound particle powder is reduced, but the nitriding rate decreases because sintering between particles proceeds.
- a preferable reduction treatment temperature is 165 to 380 ° C., more preferably 170 to 350 ° C.
- the reduction method is not particularly limited, a reduction method using hydrogen gas circulation or various hydride compounds may be used.
- the time for the reduction treatment is not particularly limited, but is preferably 1 to 24 hours. If it exceeds 24 h, depending on the reduction temperature, the sintering proceeds and the subsequent nitriding process becomes difficult to proceed. If it is less than 1 h, sufficient reduction is often not possible. More preferably, it is 1.5 to 15 hours.
- a pulverization treatment with a jet mill or a ball mill may be performed.
- an inert gas such as helium, argon, or nitrogen is preferably used.
- nitriding treatment is performed.
- the temperature of the nitriding treatment is 130 to 170 ° C.
- the nitriding temperature is less than 130 ° C.
- the nitriding does not proceed sufficiently.
- the temperature of the nitriding process exceeds 170 ° C.
- ⁇ ′-Fe 4 N and ⁇ -Fe 2 to 3 N are formed. Therefore, the Fe 16 N 2 compound phase is 80% or more from the target Mossbauer spectrum. Ferromagnetic particle powder constituted cannot be obtained.
- a more preferred reduction temperature is 135 to 165 ° C.
- the nitriding time is preferably within 50 hours. By completing the process in as short a time as possible for industrial production, the yield per hour is increased and the industrial productivity is excellent. More preferably, it is within 36 hours.
- the atmosphere of the nitriding treatment is preferably an NH 3 atmosphere, and in addition to NH 3 , a hydrocarbon gas such as N 2 , H 2, or CH 4 , and superheated steam may be mixed therewith.
- the ferromagnetic particle powder according to the present invention will be described.
- the ferromagnetic particle powder according to the present invention is composed of a Fe 16 N 2 compound phase of 80% or more from Mossbauer spectrum data.
- Mössbauer when Fe 16 N 2 is generated, a peak of an iron site having an internal magnetic field of 330 kOe or more is confirmed, and a particularly characteristic is that a peak near 395 kOe appears.
- the present invention can exhibit sufficient characteristics as a ferromagnetic hard magnet material.
- the ferromagnetic particle powder has a particle core of Fe 16 N 2 and FeO in the outer shell of the particle, and has a simple structure of Fe 16 N 2 / FeO from the core of the particle toward the outer shell.
- Fe 16 N 2 and FeO are joined topologically and are preferably crystallographically continuous.
- the outer oxide film may contain Fe 3 O 4 , Fe 2 O 3 , or ⁇ -Fe. If the Fe 16 N 2 particles have a low purity, these impurities may be contained, but due to the high purity, only FeO is obtained.
- the FeO film thickness is 5 nm or less, preferably 4 nm or less. As the purity of Fe 16 N 2 increases, this FeO film thickness decreases.
- the FeO film thickness is not particularly limited, but the thinner, the better, since the Fe 16 N 2 volume fraction contained in the particles is improved.
- the lower limit of the FeO film thickness is not particularly limited, but is about 0.5 nm.
- the volume fraction of FeO on the surface of the ferromagnetic particle powder according to the present invention is preferably 25% or less in terms of FeO volume / total particle volume. By increasing the purity of Fe 16 N 2 , the volume fraction of FeO decreases.
- the volume fraction of FeO is more preferably 23% or less, and further preferably 3 to 20%.
- the ferromagnetic particle powder according to the present invention preferably has a coercive force H C of 1.5 kOe or more and a saturation magnetization ⁇ S at 5 K of 150 emu / g or more.
- H C coercive force
- ⁇ S saturation magnetization ⁇ S at 5 K of 150 emu / g or more.
- the saturation magnetization value ⁇ s and the coercive force H c are less than the above ranges, it is difficult to say that the magnetic properties are sufficient as a hard magnetic material.
- the coercivity H c is more 1.6KOe
- saturation magnetization sigma s is 180 emu / g or more.
- the ferromagnetic particle powder according to the present invention preferably has a nitriding rate determined from a lattice constant of 8 to 13 mol%. 11.1 mol% obtained from the chemical composition formula of Fe 16 N 2 is optimal. A more preferable nitriding rate is 8.5 to 12.5 mol%, and even more preferably 9.0 to 12 mol%.
- the ferromagnetic particle powder according to the present invention preferably has a BET specific surface area of 5.0 to 40 m 2 / g.
- the BET specific surface area is less than 5 m 2 / g, the nitriding rate decreases, and as a result, the production rate of Fe 16 N 2 decreases, and the desired coercive force and saturation magnetization cannot be obtained. If it exceeds 40 m 2 / g, a desired saturation magnetization value cannot be obtained.
- a more preferable BET specific surface area is 5.5 to 38 m 2 / g, and even more preferably 6.0 to 35 m 2 / g.
- the magnetic properties of the anisotropic magnet according to the present invention may be adjusted so as to have desired magnetic properties (coercive force, residual magnetic flux density, maximum energy product) according to the intended application.
- a method for magnetic orientation is not particularly limited.
- a ferromagnetic particle powder composed of 80% or more of Fe 16 N 2 compound phase by Messbauer spectrum is kneaded with EVA (ethylene-vinyl acetate copolymer) resin together with a dispersant.
- the magnetic orientation may be promoted by applying a desired external magnetic field at a temperature near the glass transition temperature.
- a resin such as urethane, an organic solvent, and the ferromagnetic particle powder mixed and pulverized with a paint shaker or the like are applied and printed on a resin film by a blade or a Roll-to-Roll method. What is necessary is just to make it an orientation.
- RIP Resins Isostatic Pressing
- the ferromagnetic particle powder may be preliminarily coated with an insulating coating such as silica, alumina, zirconia, tin oxide, or antimony oxide.
- the method of insulating coating is not particularly limited, and vapor deposition may be performed by a method of adsorbing by controlling the particle surface potential in a solution, CVD or the like.
- the resin composition for bonded magnets in the present invention is obtained by dispersing the ferromagnetic particle powder according to the present invention in a binder resin, containing 85 to 99% by weight of the ferromagnetic particle powder, with the balance being It consists of a binder resin and other additives.
- the ferromagnetic particle powder may be preliminarily coated with an insulating coating such as silica, alumina, zirconia, tin oxide or antimony oxide.
- an insulating coating such as silica, alumina, zirconia, tin oxide or antimony oxide.
- the method of insulating coating is not particularly limited, and vapor deposition may be performed by a method of adsorbing by controlling the particle surface potential in a solution, CVD or the like.
- the binder resin can be variously selected depending on the molding method.
- a thermoplastic resin can be used, and in the case of compression molding, a thermosetting resin can be used.
- the thermoplastic resin include nylon (PA), polypropylene (PP), ethylene vinyl acetate (EVA), polyphenylene sulfide (PPS), liquid crystal resin (LCP), elastomer, and rubber.
- Resin can be used, and as the thermosetting resin, for example, epoxy resin, phenol resin or the like can be used.
- a resin composition for a bonded magnet when manufacturing a resin composition for a bonded magnet, a known plasticizer, lubricant, coupling agent, etc., in addition to a binder resin, may be used in order to facilitate molding or sufficiently draw out magnetic properties. Additives may be used. Also, other types of magnet powder such as ferrite magnet powder can be mixed.
- additives may be selected appropriately according to the purpose, and as the plasticizer, commercially available products corresponding to the respective resins used can be used, and the total amount depends on the binder resin used. On the other hand, about 0.01 to 5.0% by weight can be used.
- lubricant stearic acid and its derivatives, inorganic lubricants, oils and the like can be used, and about 0.01 to 1.0% by weight based on the whole bonded magnet can be used.
- the coupling agent a commercial product corresponding to the resin and filler used can be used, and about 0.01 to 3.0% by weight can be used with respect to the binder resin used.
- the resin composition for bonded magnets in the present invention is obtained by mixing and kneading ferromagnetic particle powder with a binder resin to obtain a bonded magnet resin composition.
- the mixing can be performed with a mixer such as a Henschel mixer, a V-shaped mixer, or Nauta, and the kneading can be performed with a uniaxial kneader, a biaxial kneader, a mortar-type kneader, an extrusion kneader, or the like.
- a mixer such as a Henschel mixer, a V-shaped mixer, or Nauta
- the kneading can be performed with a uniaxial kneader, a biaxial kneader, a mortar-type kneader, an extrusion kneader, or the like.
- the magnetic properties of the bond magnet may be adjusted so as to have desired magnetic properties (coercivity, residual magnetic flux density, maximum energy product) according to the intended application.
- the bonded magnet in the present invention is molded by a known molding method such as injection molding, extrusion molding, compression molding or calender molding using the resin composition for bonded magnet, and then electromagnetization or pulse magnetization according to a conventional method. By magnetizing, a bonded magnet can be obtained.
- the sintered magnet in the present invention may be formed by compression molding and heat treatment of ferromagnetic particle powder.
- the conditions of the magnetic field and compression molding are not particularly limited, and may be adjusted so as to be the required value of the dust magnet to be produced.
- the magnetic field is 1 to 15 T
- the compression molding pressure is 1.5 to 15 ton / cm 2 .
- molding apparatus is not specifically limited, CIP and RIP may be used. What is necessary is just to select the shape and magnitude
- the ferromagnetic particle powder may be preliminarily coated with an insulating coating such as silica, alumina, zirconia, tin oxide or antimony oxide.
- an insulating coating such as silica, alumina, zirconia, tin oxide or antimony oxide.
- the method of insulating coating is not particularly limited, and vapor deposition may be performed by a method of adsorbing by controlling the particle surface potential in a solution, CVD or the like.
- lubricant stearic acid and its derivatives, inorganic lubricants, oils and the like can be used, and about 0.01 to 1.0% by weight with respect to the entire bonded magnet may be used.
- Binders include polyolefins such as polyethylene and polypropylene, polyvinyl alcohol, polyethylene oxide, PPS, liquid crystal polymer, PEEK, polyimide, polyetherimide, polyacetal, polyethersulfone, polysulfone, polycarbonate, polyethylene terephthalate, and polybutylene terephthalate.
- a thermoplastic resin such as polyphenylene oxide, polyphthalamide, polyamide, or a mixture thereof may be used with respect to the entire bonded magnet.
- the heat treatment may be appropriately selected such as a continuous furnace or an RF high-frequency furnace.
- the heat treatment conditions are not particularly limited.
- the dust magnet according to the present invention may be obtained by compression-molding the obtained ferromagnetic particle powder in a magnetic field.
- the conditions of the magnetic field and compression molding are not particularly limited, and may be adjusted so as to be the required value of the dust magnet to be produced.
- the magnetic field is 1.0 to 15 T
- the compression molding pressure is 1.5 to 15 ton / cm 2 .
- molding apparatus is not specifically limited, CIP and RIP may be used. What is necessary is just to select the shape and magnitude
- the ferromagnetic particle powder may be preliminarily coated with an insulating coating such as silica, alumina, zirconia, tin oxide or antimony oxide.
- an insulating coating such as silica, alumina, zirconia, tin oxide or antimony oxide.
- the method of insulating coating is not particularly limited, and vapor deposition may be performed by a method of adsorbing by controlling the particle surface potential in a solution, CVD or the like.
- lubricant stearic acid and its derivatives, inorganic lubricants, oils and the like can be used, and about 0.01 to 1.0% by weight with respect to the entire bonded magnet may be used.
- Binders include polyolefins such as polyethylene and polypropylene, polyvinyl alcohol, polyethylene oxide, PPS, liquid crystal polymer, PEEK, polyimide, polyetherimide, polyacetal, polyethersulfone, polysulfone, polycarbonate, polyethylene terephthalate, and polybutylene terephthalate.
- a thermoplastic resin such as polyphenylene oxide, polyphthalamide, polyamide, or a mixture thereof may be used with respect to the entire bonded magnet.
- the heat treatment may be appropriately selected such as a continuous furnace or an RF high-frequency furnace.
- the heat treatment conditions are not particularly limited.
- a typical embodiment of the present invention is as follows.
- the specific surface area of the starting material, iron oxide or iron oxyhydroxide, and the resulting ferromagnetic particle powder is B. E. T. T. et al. Measured by the method.
- the primary particle size of the starting material iron oxide or iron oxyhydroxide and the obtained ferromagnetic particle powder was measured using a transmission electron microscope (JEOL Ltd., JEM-1200EXII). The particle size was measured by randomly selecting 120 or more particles. From the obtained data, the number average particle long axis length and deviation average, D10, D30, D60, U C , C g , and C g 2 were determined.
- (average deviation of particle long axis length) / (average particle long axis length) represents the degree of variation in primary particle long axis length.
- U C is sought than D60 / D10, represents the slope of the curvature, have as primary particles major axis length aligned close to 1, the variation of the higher number increases the primary particle major axis length increases conversely.
- C g is obtained from (D30) 2 / (D60 ⁇ D10) and represents the smoothness of the integrated distribution curve. A smaller value indicates a wider particle size distribution.
- Cg2 is calculated
- the particle size distribution of the aggregated particles of the starting material was measured with a master sizer 2000E manufactured by Malvern using pure water as a solvent. From the obtained data, values of volume converted D50 (median diameter) and D90 were obtained. Measurement data was measured by putting a predetermined amount of sample into pure water stirred at 1500 rpm with an output of 50% ultrasonic waves, and started measurement after 5 seconds. If the time until the measurement is long, the aggregated particles are dispersed and dispersed due to the ultrasonic wave and stirring, and the essence is not reflected.
- composition analysis of the iron oxide or iron oxyhydroxide as a starting material and the obtained ferromagnetic particle powder sample is performed by dissolving the heated sample with an acid, and using a plasma emission spectroscopic analyzer (Seiko Electronics Co., Ltd., SPS4000). It was determined by analysis using
- the constituent phases of the starting material and the obtained ferromagnetic particle powder were identified by a powder X-ray diffractometer (XRD, manufactured by Rigaku Corporation, RINT-2500), a transmission electron microscope (TEM, JEOL Ltd., JEM-2000EX), electron beam diffraction (ED), electron energy loss spectroscopy (EELS), and energy dispersive X-ray spectroscopy (HREM, Hitachi High-Tech, HF-2000) EDS) and scanning transmission electron microscope (STEM) analysis and evaluation were performed.
- XRD powder X-ray diffractometer
- TEM transmission electron microscope
- ED electron beam diffraction
- EELS electron energy loss spectroscopy
- HREM Hitachi High-Tech, HF-2000 EDS
- STEM scanning transmission electron microscope
- the volume fraction of FeO was evaluated as follows. First, it was confirmed that FeO was present on the particle surface using EELS for the ferromagnetic particle powder. Next, the energy state of the O (oxygen) site was analyzed at several locations about 10 nm from the vicinity of the particle surface to confirm the location of FeO. Separately, in the TEM or HREM observation of the ferromagnetic particle powder, the part where the contrast is different from the center part of the particle is confirmed, the existence position of FeO is confirmed compared with the result of the EELS, and the part where the contrast is different is FeO. Clarified that there is. The thickness of FeO was measured, and the volume fraction of FeO was calculated from the thickness of FeO and the particle shape.
- the lattice constant of the obtained ferromagnetic particle powder was determined using XRD. Based on this lattice constant, the amount of nitrogen was determined with reference to the following document.
- the magnetic properties of the obtained ferromagnetic particle powder were measured in a magnetic field of 0 to 9 T at room temperature (300 K) using a physical property measurement system (PPMS + VSM, Nippon Quantum Design Co., Ltd.). Separately, the temperature dependence of the magnetic susceptibility from 5K to 300K was also evaluated.
- Mossbauer measurement of the obtained ferromagnetic particle powder was performed by mixing the ferromagnetic particle powder with silicon grease in an argon glove box and wrapping it in an aluminum wheel, and taking 3-4 days in the range of liquid helium temperature to room temperature. Then, by analyzing the data, the production ratio of Fe 16 N 2 of the obtained ferromagnetic particle powder was determined. As an impurity phase at the time of analysis, ⁇ -Fe, Fe 4 N, Fe 3-x N, and para components such as iron oxide were examined.
- Example 1 ⁇ Adjustment of starting materials> 3.8 L of an aqueous solution in which 424 g of sodium carbonate was dissolved was set to 58 ° C., and nitrogen gas was circulated at 4 L / min. To this was added 1.2 L of an aqueous solution in which 556 g of ferrous sulfate heptahydrate was dissolved, over 30 seconds. Thereafter, 150 ml of an aqueous solution in which 15.36 g of sodium propionate was dissolved was added in 5 seconds. The solution temperature was lowered to 48 ° C. and held there for 3.5 h. Next, the flow gas was switched to oxygen and flowed at 4 L / min.
- the temperature of the aqueous solution was maintained for 3.5 hours, taking care not to exceed 50 ° C. This was separated and separated by Nutsche and washed thoroughly with 5 ml of pure water equivalent to 250 ml of pure water. Subsequently, it was dried overnight with a 125 ° C. ventilation dryer.
- the obtained sample was spindle-shaped goethite particles having an average particle major axis length of 670 nm, an aspect ratio of 12.2, and a specific surface area of 65.0 m 2 / g.
- the average particle long axis length deviation / average particle long axis length of this particle was 11.0%, U C was 1.24, C g was 0.99, and C g 2 was 0.97. .
- ⁇ Reduction treatment and nitriding treatment of starting material 50 g of the sample powder from which only aggregated particles of 250 ⁇ m or less were extracted with a vibration sieve was placed in an alumina armor (125 mm ⁇ 125 mm ⁇ depth 30 mm) and allowed to stand in a heat treatment furnace. After vacuuming the inside of the furnace, the operation of filling with argon gas and evacuating again was repeated three times. Thereafter, while flowing hydrogen gas at a flow rate of 5 L / min, the temperature was increased to 282 ° C. at a temperature increase rate of 5 ° C./min, and the reduction treatment was performed by holding for 2 hours. Thereafter, the temperature was lowered to 148 ° C. and the supply of hydrogen gas was stopped.
- the sample taken out in this state was an ⁇ -Fe single phase, and the specific surface area was 9.3 m 2 / g.
- nitriding treatment was performed at 148 ° C. for 9 h while flowing a mixed gas of ammonia gas, nitrogen gas, and hydrogen gas at a ratio of 9.5: 0.45: 0.05 in a total amount of 10 L / min.
- argon gas was circulated, the temperature was lowered to room temperature, supply of argon gas was stopped, and nitrogen substitution was performed for 3 hours. Subsequently, the sample was taken out into the glove box directly connected.
- the obtained particle powder was Fe 16 N 2 from XRD and ED, and the Fe 16 N 2 compound phase was 100% by Mossbauer spectrum measurement.
- the average particle major axis length was 631 nm, the specific surface area was 9.3 m 2 / g, and the FeO film thickness was less than 1 nm and could not be confirmed. Therefore, the volume fraction of FeO was 0%.
- the nitriding rate was 10.8%.
- Example 2 Spindle-shaped goethite was obtained in the same manner as in Example 1. However, sodium carbonate 424g (3.8L), ferrous sulfate heptahydrate 556g (1.2L), sodium propionate 15.36g (180mL), nitrogen gas amount 3.5L / min, oxygen gas amount was 4 L / min. The temperature of the sodium carbonate aqueous solution into which the ferrous sulfate aqueous solution was charged was 50 ° C., and the holding temperature during circulation of nitrogen gas and oxygen gas was 41 ° C. This was separated and separated by Nutsche and thoroughly washed with 5 ml of pure water equivalent to 180 ml of pure water.
- the obtained sample was spindle-shaped goethite particles having an average particle major axis length of 282 nm, an aspect ratio of 6.8, and a specific surface area of 112 m 2 / g.
- the average particle long axis length deviation / average particle long axis length of this particle was 9.6%, U C was 1.21, C g was 0.97, and C g 2 was 0.94. .
- it was dried overnight with a 130 ° C. ventilation dryer. Further, only aggregated particles of 90 ⁇ m or less were extracted with an atomizer pulverizer and a vibrating sieve. When the particle size distribution of this powder was measured, it was found that D50 was 21.6 ⁇ m and D90 was 64.4 ⁇ m.
- Example 2 reduction treatment and nitriding treatment were performed in the same manner as in Example 1.
- the reduction treatment was performed at 292 ° C. for 3 hours.
- the sample taken out in this state was an ⁇ -Fe single phase, and the specific surface area was 16.9 m 2 / g.
- the nitriding treatment was performed at 152 ° C. for 7 hours while flowing ammonia gas at 10 L / min.
- the obtained particle powder was Fe 16 N 2 from XRD and ED, and the Fe 16 N 2 compound phase was 93% from Mössbauer measurement.
- the average particle major axis length was 269 nm
- the specific surface area was 16.8 m 2 / g
- the FeO film thickness was 2.8 nm
- the volume fraction of FeO was 21.5%.
- the nitriding rate was 9.0%.
- the coercive force H c was 2.8 kOe.
- Example 3 180 g of ferrous chloride tetrahydrate was dissolved in 2 L of pure water to a temperature of 22 ° C. 10 minutes after flowing air at 10 L / min, 209 ml of an aqueous solution in which 11.16 g of caustic soda was dissolved was slowly added over 20 minutes, and the pH was 7.0. After 1 hour, 100 ml of the reaction solution having a pH of 6.7 was transferred to a 300 ml glass beaker, and the stirring bar was rotated at 300 rpm at room temperature for 24 hours. This was separated and separated by Nutsche and thoroughly washed with 5 ml of pure water equivalent to 200 ml of pure water.
- the obtained sample was acicular reidocrocite particles having an average particle major axis length of 2700 nm, an aspect ratio of 45.0, and a specific surface area of 83.2 m 2 / g.
- the average particle long axis length deviation / average particle long axis length was 12.2%, U C was 1.13, C g was 1.02, and C g 2 was 0.99. .
- the film was dried at 120 ° C. overnight, followed by heat treatment at 350 ° C. for 1 h. It grind
- Example 2 only aggregated particles of 180 ⁇ m or less were extracted with a vibrating sieve. Further, reduction treatment and nitriding treatment were performed in the same manner as in Example 2. The reduction was performed in a hydrogen stream at 260 ° C. for 3 hours, and the nitriding treatment was performed in an ammonia gas stream at 145 ° C. for 8 hours. The sample taken out after the reduction treatment was an ⁇ -Fe single phase, and the specific surface area was 8.3 m 2 / g.
- the obtained particle powder was Fe 16 N 2 from XRD and ED, and the Fe 16 N 2 compound phase was 88% from Mössbauer measurement.
- the average particle major axis length was 2630 nm, the specific surface area was 8.3 m 2 / g, the FeO film thickness was 2.3 nm, the volume fraction of FeO was 8.5%, and the nitriding rate was 10.6%.
- Example 4 A 500 ml aqueous solution of 32.36 g of ferric sulfate nonahydrate was used. Pure water was added to a 18.6 mol / L caustic soda solution to 1.5 L, and the temperature was raised to 65 ° C. while stirring at 280 rpm with a fluororesin anchor type stirring blade. To this caustic soda solution, the aforementioned ferric sulfate aqueous solution was added in 30 seconds, and the temperature was further raised to 95 ° C. and held for 6 hours. This was separated and separated by Nutsche and thoroughly washed with 5 ml of pure water equivalent to 200 ml of pure water.
- the obtained sample was a cubic magnetite particle having an average particle major axis length of 48 nm, an aspect ratio of 1.0, and a specific surface area of 91.0 m 2 / g.
- the average particle long axis length deviation / average particle long axis length of the particles was 15.3%, U C was 1.30, C g was 0.91, and C g 2 was 0.84. .
- Example 2 only aggregated particles of 180 ⁇ m or less were extracted with a vibrating sieve. Further, reduction treatment and nitriding treatment were performed in the same manner as in Example 2. The sample taken out after the reduction treatment was an ⁇ -Fe single phase, and the specific surface area was 38.0 m 2 / g.
- the obtained particle powder was Fe 16 N 2 from XRD and ED, and the Fe 16 N 2 compound phase was 85% from Mössbauer measurement.
- the average particle major axis length was 42 nm
- the specific surface area was 37.8 m 2 / g
- the FeO film thickness was 1.5 nm
- the volume fraction of FeO was 13.8%
- the nitriding rate was 11.8%.
- Example 5 27.05 g of ferric chloride hexahydrate was weighed into a beaker and made up to 500 ml with pure water. To this, 2.12 g of urea was added and stirred at room temperature for 30 min. Next, this solution was transferred to a closed pressure-resistant container and reacted at 85 ° C. for 3.5 hours while stirring with a stirring blade at 200 rpm. This was separated and separated by Nutsche, and washed thoroughly with pure water equivalent to 30 ml of pure water for 1 g of the sample. The obtained sample was acicular akaganite having an average particle major axis length of 130 nm, an aspect ratio of 2.6, and a specific surface area of 96.0 m 2 / g.
- the average particle long axis length deviation / average particle long axis length of this particle was 8.7%, U C was 1.09, C g was 0.99, and C g 2 was 0.98. . Then, it was dried at 40 ° C. overnight.
- pulverization was performed in a wet bead mill in the same manner as in Example 4.
- D50 was 5.6 ⁇ m and D90 was 10.7 ⁇ m.
- only aggregated particles of 180 ⁇ m or less were extracted with a vibrating sieve.
- reduction treatment and nitriding treatment were performed in the same manner as in Example 2. The reduction treatment was performed in a hydrogen stream at 292 ° C.
- the sample taken out after the reduction treatment was an ⁇ -Fe single phase, and the specific surface area was 20.0 m 2 / g.
- the obtained particle powder was Fe 16 N 2 from XRD and ED, and the Fe 16 N 2 compound phase was 84% from Mossbauer measurement.
- the average particle major axis length was 122 nm, the specific surface area was 19.9 m 2 / g, the FeO film thickness was 1.9 nm, the volume fraction of FeO was 19.5%, and the nitriding rate was 11.6%.
- Comparative Example 1 In the same manner as in Example 2, a sample in which a spindle-shaped goethite particle main phase having an average particle major axis length of 143 nm, an aspect ratio of 4.9, and a specific surface area of 130 m 2 / g and a cubic magnetite of only about 20 to 50 nm are mixed. Obtained. The amount of each raw material used was the same, but the ferrous sulfate aqueous solution was not added in 30 seconds, but was dropped over 10 minutes, the flow rate of nitrogen gas was 2 L / min, and the flow rate of air gas was 18 L / The reaction temperature was 55 ° C. during circulation of air gas.
- the average particle long axis length deviation / average particle long axis length of this particle was 66.0%, U C was 1.58, C g was 0.95, and C g 2 was 0.34. . Subsequently, the film was dried overnight in a ventilation dryer at 130 ° C. Next, pulverization was performed in an alumina mortar for 0.5 h to obtain a powder sample having D50 of 14.5 ⁇ m and D90 of 39.9 ⁇ m.
- Example 2 reduction treatment and nitriding treatment were performed in the same manner as in Example 1.
- the reduction treatment was performed at 290 ° C. for 4.5 hours.
- the sample taken out in this state was an ⁇ -Fe single phase, and the specific surface area was 19.4 m 2 / g.
- the nitriding treatment was performed at 155 ° C. for 8 hours while flowing ammonia gas at 10 L / min. After the nitriding treatment, the inside of the furnace was purged with nitrogen at room temperature and taken out of the furnace as it was.
- the obtained particle powder contained Fe 16 N 2 , Fe 4 N, and ⁇ -Fe from XRD and ED, and the Fe 16 N 2 compound phase was 68% from Mössbauer measurement.
- the average particle major axis length was 122 nm
- the specific surface area was 19.4 m 2 / g
- the FeO film thickness was 8.8 nm
- the volume fraction of FeO was 55.7%.
- the nitriding rate was 7.3%.
- the coercive force H c was 1.2 kOe.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Crystallography & Structural Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Hard Magnetic Materials (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
まず、強磁性粒子粉末についてEELSを用いてFeOが粒子表面上に存在することを確認した。次いで、粒子表面近傍から10nm程度の何カ所かにおいてO(酸素)サイトのエネルギー状態を分析してFeOの存在位置を確認した。また別に強磁性粒子粉末のTEMあるいはHREM観察において、粒子の中心部とコントラストが異なる部分を確認し、前記EELSの結果と比較しFeOの存在位置を確認して、このコントラストが異なる部分がFeOであることを明らかにした。FeOの厚さを測定し、FeOの厚さと粒子形状からFeOの体積分率を算出した。
・高橋有紀子
東北大学大学院 工学研究科 電子工学専攻 2001年博士学位論文
題目:「(C,N)添加Fe基合金薄膜における非平衡α’、α"、γ相の合成と磁性に関する研究」
・K.H.Jack,
Proc. Roy. Soc., A208, 216(1951)
“The iron-nitrogen system: the preparation and the crystal structures of nitrogen-austenite(γ) and nitrogen-martensite(α’)”
<出発原料の調整>
炭酸ソーダ424gを溶かした水溶液3.8Lを58℃として窒素ガスを4L/min流通させた。これに硫酸第一鉄7水塩を556g溶解した水溶液1.2Lを30秒間で投入した。その後、プロピオン酸ナトリウム15.36gを溶解させた150mlの水溶液を5秒で投入した。溶液温度は48℃まで下がり、そのまま3.5h保持させた。次に流通ガスを酸素に切り替えて4L/minにて流通させた。水溶液の温度は50℃を超えないように注意しながら、3.5h保持した。これをヌッチェで濾別分離して、試料5gに対して純水250ml相当の純水でよく洗浄した。続いて、125℃の通風乾燥機にて1晩乾燥させた。得られた試料は、平均粒子長軸長670nm、アスペクト比12.2、比表面積65.0m2/gの紡錘状ゲータイト粒子であった。この粒子の(粒子長軸長の偏差平均)/(平均粒子長軸長)は11.0%、UCは1.24、Cgは0.99、Cg2は0.97であった。
次に、ヘキサン溶媒40mlに乾燥粉末試料3gを加え、3mmφの窒化ケイ素ビーズとともに、窒素ガス置換を行った遊星ボールミルにて室温で0.5hの粉砕を行い、再び粉末を取り出した。この粉末の粒度分布測定を行ったところ、D50が15.9μm、D90が48.0μmであった。
振動篩で250μm以下の凝集粒子のみを抽出した上記試料粉末50gをアルミナ製甲鉢(125mm×125mm×深さ30mm)に入れ、熱処理炉に静置させた。炉内を真空引きした後、アルゴンガスを充填し、再び真空引きする操作を3回繰り返した。その後、水素ガスを5L/minの流量で流しながら、5℃/minの昇温速度で282℃まで昇温し、2h保持して還元処理を行った。その後、148℃まで降温して水素ガスの供給を止めた。なお、この状態で取り出した試料は、α-Fe単相で、比表面積は9.3m2/gであった。続いて、アンモニアガスと窒素ガスと水素ガスの混合比が9.5:0.45:0.05の混合ガスを全量で10L/min流しながら、148℃で9h窒化処理を行った。その後、アルゴンガスを流通させて室温まで降温し、アルゴンガス供給を止めて、窒素置換を3hかけて行った。次いで、直結しているグローブボックスに試料を取り出た。
得られた粒子粉末はXRD、EDよりFe16N2であり、メスバウアースペクトル測定により、Fe16N2化合物相は100%であった。平均粒子長軸長631nm、比表面積は9.3m2/g、FeO膜厚は1nm未満で確認できなかった。従ってFeOの体積分率は0%であった。また、窒化率は10.8%であった。磁気特性を測定したところ、5Kでの飽和磁化値σs=235emu/g、保磁力Hc=2.6kOeであった。
実施例1と同様にして、紡錘状ゲータイトを得た。ただし、炭酸ソーダは424g(3.8L)、硫酸第一鉄7水塩は556g(1.2L)、プロピオン酸ナトリウム15.36g(180mL)、窒素ガス量は3.5L/min、酸素ガス量は4L/minとした。また、硫酸第一鉄水溶液を投入する炭酸ソーダ水溶液温度は50℃、窒素ガス及び酸素ガス流通中の保持温度は41℃とした。これをヌッチェで濾別分離し、試料5gに対して純水180ml相当の純水でよく洗浄した。得られた試料は、平均粒子長軸長282nm、アスペクト比6.8、比表面積112m2/gの紡錘状ゲータイト粒子であった。この粒子の(粒子長軸長の偏差平均)/(平均粒子長軸長)は9.6%、UCは1.21、Cgは0.97、Cg2は0.94であった。続いて、130℃の通風乾燥機にて1晩乾燥させた。さらにアトマイザー粉砕機と振動篩で90μm以下の凝集粒子のみを抽出した。この粉末の粒度分布測定を行ったところ、D50が21.6μm、D90が64.4μmであった。
塩化第一鉄4水塩180gを2Lの純水に溶解させて22℃とした。空気を10L/min流通させて10分後に11.16gの苛性ソーダを溶かした209mlの水溶液を20分かけてゆっくりと加え、pHは7.0であった。1時間後、pH6.7となった反応溶液の100mlを300mlガラスビーカーに移し、室温にて、撹拌子を300rpmで回転させ24h反応した。これをヌッチェで濾別分離し、試料5gに対して純水200ml相当の純水でよく洗浄した。得られた試料は、平均粒子長軸長2700nm、アスペクト比45.0、比表面積83.2m2/gの針状レピドクロサイト粒子であった。この粒子の(粒子長軸長の偏差平均)/(平均粒子長軸長)は12.2%、UCは1.13、Cgは1.02、Cg2は0.99であった。120℃で1晩乾燥させ、続けて350℃で1hの熱処理を行った。瑪瑙乳鉢を用いたライカイ機で1h粉砕した。この粉末の粒度分布測定を行ったところ、D50が5.3μm、D90が13.8μmであった。さらに振動篩で180μm以下の凝集粒子のみを抽出した。さらに、還元処理と窒化処理を実施例2同様に行った。還元は水素気流中で260℃にて3h、窒化処理はアンモニアガス気流中で145℃にて8hそれぞれ行った。なお、還元処理後の状態で取り出した試料は、α-Fe単相で、比表面積は8.3m2/gであった。
硫酸第二鉄9水塩32.36gを500ml水溶液とした。18.6mol/Lの苛性ソーダ溶液に純水を加えて1.5Lとして、フッ素樹脂製アンカー型撹拌翼で280rpmにて撹拌しながら65℃に昇温した。この苛性ソーダ溶液に、上記した硫酸第二鉄水溶液を30秒間で投入し、さらに95℃に昇温して、6h保持した。これをヌッチェで濾別分離し、試料5gに対して純水200ml相当の純水でよく洗浄した。得られた試料は、平均粒子長軸長48nm、アスペクト比1.0、比表面積91.0m2/gの立方体状マグネタイト粒子であった。この粒子の(粒子長軸長の偏差平均)/(平均粒子長軸長)は15.3%、UCは1.30、Cgは0.91、Cg2は0.84であった。これをトルエン溶媒中15wt%固形分濃度で500μmの窒化ケイ素製ビーズを用いて湿式ビーズミル粉砕した。この粉末の粒度分布測定を行ったところ、D50が9.6μm、D90が15.3μmであった。さらに振動篩で180μm以下の凝集粒子のみを抽出した。さらに、還元処理と窒化処理を実施例2同様に行った。なお、還元処理後の状態で取り出した試料は、α-Fe単相で、比表面積は38.0m2/gであった。
塩化第二鉄6水塩27.05gをビーカーに秤取り純水で500mlとした。これに尿素2.12gを加えて、室温で30min撹拌した。次にこの溶液を閉鎖系の圧力耐性容器に移して撹拌翼にて200rpmで撹拌子ながら85℃にて3.5h反応した。これをヌッチェで濾別分離し、試料1gに対して純水30ml相当の純水でよく洗浄した。得られた試料は、平均粒子長軸長130nm、アスペクト比2.6、比表面積96.0m2/gの針状アカガナイトであった。この粒子の(粒子長軸長の偏差平均)/(平均粒子長軸長)は8.7%、UCは1.09、Cgは0.99、Cg2は0.98であった。次いで、40℃で1晩乾燥させた。アトマイザー粉砕機後、実施例4同様に湿式ビーズミルにて粉砕処理を行った。この粉末の粒度分布測定を行ったところ、D50が5.6μm、D90が10.7μmであった。さらに振動篩で180μm以下の凝集粒子のみを抽出した。さらに、還元処理と窒化処理を実施例2同様に行った。還元処理は水素気流中で292℃にて2h、窒化処理はアンモニアガス気流中で150℃にて8hそれぞれ行った。なお、還元処理後の状態で取り出した試料は、α-Fe単相で、比表面積は20.0m2/gであった。
実施例2と同様にして、平均粒子長軸長143nm、アスペクト比4.9、比表面積130m2/gの紡錘状ゲータイト粒子主相、わずかに20~50nm程度の立方体状マグネタイトが混在した試料を得た。各原料の使用量は同じであったが、硫酸第一鉄水溶液を30秒間での投入とせず、10minかけて滴下し、窒素ガスの流通量を2L/min、空気ガスの流通量を18L/minとし、さらに空気ガス流通時の反応温度を55℃とした。この粒子の(粒子長軸長の偏差平均)/(平均粒子長軸長)は66.0%、UCは1.58、Cgは0.95、Cg2は0.34であった。続いて、130℃の通風乾燥機にて1晩乾燥させた。次に、アルミナ乳鉢にて粉砕を0.5h行い、D50が14.5μm、D90が39.9μmの粉末試料を得た。
Claims (9)
- 鉄化合物粒子粉末を160~420℃にて還元処理し、次いで、130~170℃にて窒化処理する強磁性粒子粉末の製造方法において、前記鉄化合物粒子粉末として、平均粒子長軸長が40~5000nmであり、アスペクト比(長軸径/短軸径)が1~200であり、(粒子長軸長の偏差平均)/(平均粒子長軸長)が50%以下であり、均等係数(UC)が1.55以下であり、曲率係数(Cg)が0.95以上であり、広範囲の曲率係数(Cg2)が0.40以上である鉄化合物粒子粉末を用いることを特徴とする強磁性粒子粉末の製造方法。
- 鉄化合物粒子粉末が、マグネタイト、ヘマタイト及びゲータイトから選ばれる一種以上である請求項1記載の強磁性粒子粉末の製造方法。
- 得られる強磁性粒子が粒子外殻にFeOが存在するとともにFeOの膜厚が5nm以下である請求項1又は2に記載の強磁性粒子粉末の製造方法。
- 得られる強磁性粒子粉末のFeOの体積分率が、FeO体積/粒子全体体積において25%以下である請求項1~3のいずれかに記載の強磁性粒子粉末の製造方法。
- 得られる強磁性粒子粉末の保磁力HCが1.5kOe以上、5Kでの飽和磁化σSが150emu/g以上である請求項1~4のいずれかに記載の強磁性粒子粉末の製造方法。
- 得られる強磁性粒子粉末の格子定数から算出される窒化率が8.0~13mol%である請求項1~5のいずれかに記載の強磁性粒子粉末の製造方法。
- 請求項1~6のいずれかに記載の製造方法によって強磁性粒子粉末を得る工程と、磁気的配向を行う工程とから成る異方性磁石の製造方法。
- 請求項1~6のいずれかに記載の製造方法によって強磁性粒子粉末を得る工程と、得られた強磁性粒子粉末を結合剤樹脂に分散させて混合物を得る工程と、混合物を成形する工程とから成るボンド磁石の製造方法。
- 請求項1~6のいずれかに記載の製造方法によって強磁性粒子粉末を得る工程と、得られた強磁性粒子粉末を磁場中で圧縮成形する工程とから成る圧粉磁石の製造方法。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/113,711 US20140085023A1 (en) | 2011-04-27 | 2012-04-26 | Process for producing ferromagnetic particles, anisotropic magnet, bonded magnet and compacted magnet |
EP12776047.8A EP2704159A4 (en) | 2011-04-27 | 2012-04-26 | FERROMAGNETIC PARTICLE POWDER PRODUCTION PROCESS, AND ANISOTROPIC MAGNET, BONDED MAGNET, AND COMPACT MAGNET |
KR1020137027502A KR20140031220A (ko) | 2011-04-27 | 2012-04-26 | 강자성 입자 분말의 제조 방법, 이방성 자석, 본드 자석 및 압분 자석 |
CN201280020148.0A CN103493154A (zh) | 2011-04-27 | 2012-04-26 | 强磁性颗粒粉末的制造方法、各向异性磁体、粘结磁体和压粉磁体 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011100177A JP5858419B2 (ja) | 2011-04-27 | 2011-04-27 | 強磁性粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 |
JP2011-100177 | 2011-04-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2012147833A1 true WO2012147833A1 (ja) | 2012-11-01 |
Family
ID=47072348
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/061176 WO2012147833A1 (ja) | 2011-04-27 | 2012-04-26 | 強磁性粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 |
Country Status (7)
Country | Link |
---|---|
US (1) | US20140085023A1 (ja) |
EP (1) | EP2704159A4 (ja) |
JP (1) | JP5858419B2 (ja) |
KR (1) | KR20140031220A (ja) |
CN (1) | CN103493154A (ja) |
TW (1) | TW201310480A (ja) |
WO (1) | WO2012147833A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015003850A1 (de) * | 2013-07-12 | 2015-01-15 | Siemens Aktiengesellschaft | Hochgefüllte matrixgebundene anisotrope hochleistungspermanentmagnete und verfahren zu deren herstellung |
WO2015003848A1 (de) * | 2013-07-12 | 2015-01-15 | Siemens Aktiengesellschaft | Anisotroper seltenerdfreier matrixgebundener hochperformanter permanentmagnet mit nanokristalliner struktur und verfahren zu dessen herstellung |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5831866B2 (ja) * | 2011-01-21 | 2015-12-09 | 戸田工業株式会社 | 強磁性粒子粉末及びその製造方法、並びに異方性磁石、ボンド磁石及び圧粉磁石 |
JP5846540B2 (ja) * | 2011-07-06 | 2016-01-20 | 住友電気工業株式会社 | 窒化鉄粉末の製造方法 |
JP6380736B2 (ja) * | 2013-06-12 | 2018-08-29 | Tdk株式会社 | 窒化鉄系磁性粉及びそれを用いた磁石 |
US9994949B2 (en) * | 2014-06-30 | 2018-06-12 | Regents Of The University Of Minnesota | Applied magnetic field synthesis and processing of iron nitride magnetic materials |
KR20170039303A (ko) * | 2014-08-08 | 2017-04-10 | 리전츠 오브 더 유니버시티 오브 미네소타 | 화학 증착 또는 액상 에피택시를 사용하여 질화철 경자성 재료를 형성하는 방법 |
AU2016211751A1 (en) * | 2015-01-26 | 2017-08-17 | Regents Of The University Of Minnesota | Iron nitride powder with anisotropic shape |
JP2016207710A (ja) * | 2015-04-16 | 2016-12-08 | 株式会社ジェイテクト | 磁石の製造方法及び磁石 |
EP3528253B1 (en) * | 2016-10-17 | 2021-08-25 | Sony Group Corporation | Method for producing a magnetic powder |
US11521649B2 (en) | 2016-11-11 | 2022-12-06 | Sony Corporation | Method of producing a magnetic powder and method of producing a magnetic recording medium |
JP6778653B2 (ja) * | 2017-05-24 | 2020-11-04 | Tdk株式会社 | 窒化鉄系磁石 |
CN107564643B (zh) * | 2017-09-25 | 2018-10-16 | 北京航空航天大学 | 一种纳米颗粒基各向异性双相复合磁体及制备方法 |
CN111073573B (zh) * | 2018-10-19 | 2022-09-23 | 北京航天试验技术研究所 | 一种空间站用复合堵漏剂 |
CN109599240B (zh) * | 2018-11-21 | 2020-09-18 | 湖南金泓电子科技有限责任公司 | 一种铁氧体类软磁粉芯及其制备方法 |
CN111370217B (zh) * | 2020-03-19 | 2021-07-13 | 中国科学院宁波材料技术与工程研究所 | 一种光固化辅助直写3d打印制备永磁体的方法 |
JP2023012279A (ja) * | 2021-07-13 | 2023-01-25 | Jx金属株式会社 | 磁性粒子粉末及び磁性粒子分散液 |
US20230241255A1 (en) * | 2022-01-31 | 2023-08-03 | The Texas A&M University System | Magnetic resonance contrast agents and methods thereof |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11340023A (ja) | 1998-05-22 | 1999-12-10 | Dowa Mining Co Ltd | 磁性材料およびその製法 |
JP2000277311A (ja) | 1999-03-25 | 2000-10-06 | Toyota Central Res & Dev Lab Inc | 窒化鉄系磁性粉末材料及びその製造方法並びに磁気記録媒体 |
JP2007036027A (ja) | 2005-07-28 | 2007-02-08 | Dowa Holdings Co Ltd | 低ノイズ媒体に適した磁性粉末 |
JP2007134614A (ja) | 2005-11-14 | 2007-05-31 | Dowa Electronics Materials Co Ltd | 高保磁力鉄系磁性粉末及び磁気記録媒体 |
JP2007258427A (ja) | 2006-03-23 | 2007-10-04 | Tdk Corp | 磁性粒子及びその製造方法 |
JP2007335592A (ja) | 2006-06-14 | 2007-12-27 | Dowa Electronics Materials Co Ltd | 窒化鉄系磁性粉末およびその製造法並びに磁気記録媒体 |
JP2008103510A (ja) | 2006-10-18 | 2008-05-01 | Dowa Electronics Materials Co Ltd | 窒化鉄系磁性粉末およびその製造法 |
JP2008108943A (ja) | 2006-10-26 | 2008-05-08 | Hitachi Maxell Ltd | 磁性粉末およびそれを用いた磁気記録媒体 |
JP2009084115A (ja) | 2007-09-28 | 2009-04-23 | Fujifilm Corp | 窒化鉄粉末の製造方法、窒化鉄粉末および磁気記録媒体 |
JP2009249682A (ja) | 2008-04-04 | 2009-10-29 | Nec Tokin Corp | 硬磁性合金およびその製造方法 |
JP2010147079A (ja) * | 2008-12-16 | 2010-07-01 | Hitachi Maxell Ltd | 窒化鉄系磁性粉末の製造方法と窒化鉄系磁性粉末。 |
JP2012069811A (ja) * | 2010-09-24 | 2012-04-05 | Toda Kogyo Corp | 強磁性粒子粉末及びその製造法、異方性磁石及びボンド磁石 |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2403587B (en) * | 2002-03-18 | 2005-08-03 | Hitachi Maxell | Magnetic recording medium and magnetic recording cartridge |
EP1548760A3 (en) * | 2003-11-27 | 2007-12-26 | DOWA Electronics Materials Co., Ltd. | Iron nitride magnetic powder and method of producing the powder |
JP2005228377A (ja) * | 2004-02-10 | 2005-08-25 | Hitachi Maxell Ltd | 磁気テープ |
JP4534059B2 (ja) * | 2004-03-17 | 2010-09-01 | Dowaエレクトロニクス株式会社 | 窒化鉄系磁性粉末およびその製造法 |
JP4734599B2 (ja) * | 2004-08-02 | 2011-07-27 | Dowaエレクトロニクス株式会社 | 耐候性の良い窒化鉄系磁性粉末およびその製造法 |
JP2007036183A (ja) * | 2005-06-21 | 2007-02-08 | Fujifilm Holdings Corp | 磁性粒子の製造方法、磁性粒子、磁気記録媒体 |
JP2007254267A (ja) * | 2006-02-23 | 2007-10-04 | Tdk Corp | オキシ水酸化鉄粒子の製造方法 |
WO2008062757A1 (fr) * | 2006-11-21 | 2008-05-29 | Ulvac, Inc. | Procédé de production d'un objet orienté, d'un objet moulé, et d'un objet fritté et procédé de production d'un aimant permanent |
-
2011
- 2011-04-27 JP JP2011100177A patent/JP5858419B2/ja not_active Expired - Fee Related
-
2012
- 2012-04-26 WO PCT/JP2012/061176 patent/WO2012147833A1/ja active Application Filing
- 2012-04-26 EP EP12776047.8A patent/EP2704159A4/en not_active Withdrawn
- 2012-04-26 CN CN201280020148.0A patent/CN103493154A/zh active Pending
- 2012-04-26 KR KR1020137027502A patent/KR20140031220A/ko not_active Application Discontinuation
- 2012-04-26 US US14/113,711 patent/US20140085023A1/en not_active Abandoned
- 2012-04-27 TW TW101115151A patent/TW201310480A/zh unknown
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11340023A (ja) | 1998-05-22 | 1999-12-10 | Dowa Mining Co Ltd | 磁性材料およびその製法 |
JP2000277311A (ja) | 1999-03-25 | 2000-10-06 | Toyota Central Res & Dev Lab Inc | 窒化鉄系磁性粉末材料及びその製造方法並びに磁気記録媒体 |
JP2007036027A (ja) | 2005-07-28 | 2007-02-08 | Dowa Holdings Co Ltd | 低ノイズ媒体に適した磁性粉末 |
JP2007134614A (ja) | 2005-11-14 | 2007-05-31 | Dowa Electronics Materials Co Ltd | 高保磁力鉄系磁性粉末及び磁気記録媒体 |
JP2007258427A (ja) | 2006-03-23 | 2007-10-04 | Tdk Corp | 磁性粒子及びその製造方法 |
JP2007335592A (ja) | 2006-06-14 | 2007-12-27 | Dowa Electronics Materials Co Ltd | 窒化鉄系磁性粉末およびその製造法並びに磁気記録媒体 |
JP2008103510A (ja) | 2006-10-18 | 2008-05-01 | Dowa Electronics Materials Co Ltd | 窒化鉄系磁性粉末およびその製造法 |
JP2008108943A (ja) | 2006-10-26 | 2008-05-08 | Hitachi Maxell Ltd | 磁性粉末およびそれを用いた磁気記録媒体 |
JP2009084115A (ja) | 2007-09-28 | 2009-04-23 | Fujifilm Corp | 窒化鉄粉末の製造方法、窒化鉄粉末および磁気記録媒体 |
JP2009249682A (ja) | 2008-04-04 | 2009-10-29 | Nec Tokin Corp | 硬磁性合金およびその製造方法 |
JP2010147079A (ja) * | 2008-12-16 | 2010-07-01 | Hitachi Maxell Ltd | 窒化鉄系磁性粉末の製造方法と窒化鉄系磁性粉末。 |
JP2012069811A (ja) * | 2010-09-24 | 2012-04-05 | Toda Kogyo Corp | 強磁性粒子粉末及びその製造法、異方性磁石及びボンド磁石 |
Non-Patent Citations (6)
Title |
---|
"Study on synthesis and magnetism of non-equilibrium a',a'',y phases in (C, N)-added Fe-based alloy thin layer", DOCTORIAL THESIS OF GRADUATE SCHOOL OF TOHOKU UNIVERSITY, SCHOOL OF ENGINEERING, ELECTRICAL ENGINEERING, 2001 |
K. H. JACK: "The iron-nitrogen system: the preparation and the crystal structures of nitrogen-austenite (y) and nitrogen-martensite (a", PROC. ROY. SOC., vol. A208, 1951, pages 216 |
M. TAKAHASHI; H. SHOJI; H. TAKAHASHI; H. NASHI; T. WAKIYAMA; M. DOI; M. MATSUI, J. APPL. PHYS., vol. 76, 1994, pages 6642 - 6647 |
TAKESHI HATTORI ET AL.: "Magnetic Properties of Fe16N2 Fine Particles", JOURNAL OF MAGNETICS SOCIETY OF JAPAN, vol. 25, no. 4-2, 2001, pages 927 - 930, XP009114659 * |
Y. TAKAHASHI; M. KATOU; H. SHOJI; M. TAKAHASHI, J. MAGN. MAGN. MATER., vol. 232, 2001, pages 18 - 26 |
YUKI ONUMA ET AL.: "Humidity effects in Fe16N2 fine powder preparation by low-temperature nitridation", ABSTRACTS OF MEETING OF JAPAN SOCIETY OF POWDER AND POWDER METALLURGY, vol. 2006, 5 December 2006 (2006-12-05), pages 123, XP055106705 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015003850A1 (de) * | 2013-07-12 | 2015-01-15 | Siemens Aktiengesellschaft | Hochgefüllte matrixgebundene anisotrope hochleistungspermanentmagnete und verfahren zu deren herstellung |
WO2015003848A1 (de) * | 2013-07-12 | 2015-01-15 | Siemens Aktiengesellschaft | Anisotroper seltenerdfreier matrixgebundener hochperformanter permanentmagnet mit nanokristalliner struktur und verfahren zu dessen herstellung |
Also Published As
Publication number | Publication date |
---|---|
JP2012231098A (ja) | 2012-11-22 |
EP2704159A1 (en) | 2014-03-05 |
JP5858419B2 (ja) | 2016-02-10 |
CN103493154A (zh) | 2014-01-01 |
EP2704159A4 (en) | 2014-12-03 |
KR20140031220A (ko) | 2014-03-12 |
TW201310480A (zh) | 2013-03-01 |
US20140085023A1 (en) | 2014-03-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5858419B2 (ja) | 強磁性粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 | |
JP5831866B2 (ja) | 強磁性粒子粉末及びその製造方法、並びに異方性磁石、ボンド磁石及び圧粉磁石 | |
JP5924657B2 (ja) | 強磁性窒化鉄粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 | |
JP5822188B2 (ja) | 強磁性粒子粉末及びその製造法、異方性磁石及びボンド磁石 | |
JP6155440B2 (ja) | 強磁性窒化鉄粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石の製造方法 | |
WO2013042721A1 (ja) | 強磁性窒化鉄粒子粉末の製造方法、異方性磁石、ボンド磁石及び圧粉磁石 | |
TWI498926B (zh) | A ferromagnetic particle powder and a method for producing the same, an isotropic magnet, and a bond magnet, | |
US9607740B2 (en) | Hard-soft magnetic MnBi/SiO2/FeCo nanoparticles | |
US9427805B2 (en) | Method to prepare hard-soft magnetic FeCo/ SiO2/MnBi nanoparticles with magnetically induced morphology |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12776047 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20137027502 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012776047 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14113711 Country of ref document: US |