WO2014058067A1 - Sr ferrite powder, method for manufacturing sr ferrite sintered magnet, motor, and generator - Google Patents

Sr ferrite powder, method for manufacturing sr ferrite sintered magnet, motor, and generator Download PDF

Info

Publication number
WO2014058067A1
WO2014058067A1 PCT/JP2013/077837 JP2013077837W WO2014058067A1 WO 2014058067 A1 WO2014058067 A1 WO 2014058067A1 JP 2013077837 W JP2013077837 W JP 2013077837W WO 2014058067 A1 WO2014058067 A1 WO 2014058067A1
Authority
WO
WIPO (PCT)
Prior art keywords
ferrite
powder
magnet
calcined body
sintered
Prior art date
Application number
PCT/JP2013/077837
Other languages
French (fr)
Japanese (ja)
Inventor
田口　仁
Original Assignee
Tdk株式会社
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 Tdk株式会社 filed Critical Tdk株式会社
Priority to CN201380040883.2A priority Critical patent/CN104507889A/en
Priority to JP2014540917A priority patent/JPWO2014058067A1/en
Publication of WO2014058067A1 publication Critical patent/WO2014058067A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/62605—Treating the starting powders individually or as mixtures
    • C04B35/62645—Thermal treatment of powders or mixtures thereof other than sintering
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/0018—Mixed oxides or hydroxides
    • C01G49/0036—Mixed oxides or hydroxides containing one alkaline earth metal, magnesium or lead
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/62605—Treating the starting powders individually or as mixtures
    • C04B35/6261—Milling
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • 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
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3201—Alkali metal oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3201—Alkali metal oxides or oxide-forming salts thereof
    • C04B2235/3203—Lithium oxide or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3213—Strontium oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
    • C04B2235/3227—Lanthanum oxide or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3427—Silicates other than clay, e.g. water glass
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5409—Particle size related information expressed by specific surface values
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
    • C04B2235/605—Making or treating the green body or pre-form in a magnetic field
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/66—Specific sintering techniques, e.g. centrifugal sintering
    • C04B2235/661—Multi-step sintering
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/76—Crystal structural characteristics, e.g. symmetry
    • C04B2235/767—Hexagonal symmetry, e.g. beta-Si3N4, beta-Sialon, alpha-SiC or hexa-ferrites

Definitions

  • the present invention relates to a method for producing Sr ferrite powder and a sintered Sr ferrite magnet, and a motor and a generator including the Sr ferrite sintered magnet obtained by the production method.
  • M type Sr ferrite As a magnetic material used for a ferrite sintered magnet, Ba ferrite, Sr ferrite, and Ca ferrite having a hexagonal crystal structure are known. In recent years, among them, magnetoplumbite type (M type) Sr ferrite is mainly used as a magnet material for motors and the like.
  • the M-type ferrite is represented by a general formula of AFe 12 O 19 , for example.
  • Sr ferrite has Sr at the A site of the crystal structure.
  • Patent Document 1 discloses a technique for improving the residual magnetic flux density (Br) and the coercive force (HcJ) by replacing a part of the A site and the B site with a specific amount of rare earth element and Co. .
  • Sr ferrite magnets used in motors and generators are required to be reduced in size and weight, and in order to cope with this, it is required to further increase the magnetic characteristics.
  • Patent Document 1 it is effective to improve the magnetic characteristics by controlling the composition of main crystal grains constituting the Sr ferrite sintered magnet.
  • the composition of main crystal grains constituting the Sr ferrite sintered magnet even if only the composition of the crystal grains is controlled, it is difficult to greatly improve the magnetic characteristics of the conventional Sr ferrite sintered magnet.
  • refine the structure As a means for refining the structure, it can be considered that the calcined body used as a raw material of the sintered Sr ferrite magnet is atomized.
  • a method for atomizing the calcined body a method of mechanically crushing the calcined body and lengthening the crushing time can be mentioned.
  • the mechanically pulverized in this way the particle size distribution becomes wide.
  • the manufacturing cost increases due to increased power consumption, equipment wear, and the like, and the yield decreases.
  • anisotropic Sr ferrite sintered magnets whose crystal orientation is in the c-axis direction are currently mainstream.
  • an anisotropic Sr ferrite sintered magnet is manufactured, it is necessary to advance the ferritization reaction sufficiently in the calcining step in order to increase the orientation of the ferrite particles by the magnetic field at the stage of forming the molded body. .
  • calcination and baking were generally performed at a high temperature of 1250 ° C. or higher.
  • energy costs in the calcination step and the firing step increased, and ferrite particles grew to several ⁇ m to several tens of ⁇ m.
  • This invention is made
  • the present inventors have studied various methods for producing Sr ferrite powder used as a raw material in order to refine the structure of the sintered Sr ferrite magnet. As a result, it has been found that the temperature at which Sr ferrite is generated can be significantly reduced by adding a compound having Li as a constituent element. And it discovered that the Sr ferrite sintered magnet which has high Br can be manufactured by using Sr ferrite powder obtained by calcining at low temperature, and came to complete this invention.
  • a mixture containing an iron compound powder, a strontium compound powder, and a compound powder containing Li as a constituent element is fired at 850 to 1050 ° C. to obtain a hexagonal crystal structure.
  • a Sr ferrite powder including a calcined body or a pulverized powder thereof having a calcined step of obtaining a calcined body containing 0.01 to 0.5% by mass of Li in terms of Li 2 O A manufacturing method is provided.
  • a fine Sr ferrite powder having high saturation magnetization ( ⁇ s ) can be easily obtained.
  • the present inventors presume this reason as follows. That is, in the method for producing Sr ferrite powder of the present invention, a mixture containing a powder of a compound having Li as a constituent element is used as a raw material for producing Sr ferrite powder. It is believed that this Li has the action of promoting the formation of Sr ferrite, and as a result, it is possible to obtain a calcined body having a high saturation magnetization by forming Sr ferrite at a calcining temperature of 800 to 1050 ° C. Yes.
  • the grain growth of Sr ferrite can be sufficiently suppressed. If such a calcined body is pulverized as necessary, a sufficiently fine Sr ferrite powder having high saturation magnetization can be easily obtained.
  • the Sr ferrite powder obtained in this way produces Sr ferrite sintered magnets that are required to have high Br because the particles are fine and have high uniformity and also have high saturation magnetization. It can be particularly suitably used as a raw material for the purpose.
  • the method for producing Sr ferrite powder of the present invention preferably includes a pulverization step of pulverizing the calcined body to obtain a pulverized powder containing Sr ferrite.
  • a pulverization step of pulverizing the calcined body to obtain a pulverized powder containing Sr ferrite.
  • the specific surface area by the BET method of the calcined body obtained in the calcining step is preferably 2 m 2 / g or more and the saturation magnetization is 67 emu / g or more.
  • Such a calcined body is finer and has a high saturation magnetization. For this reason, when the Sr ferrite powder containing this calcined body or its pulverized powder is sintered to produce a Sr ferrite sintered magnet, even if the sintering temperature is lowered, Sr ferrite sintered having a sufficiently high Br is obtained.
  • a magnetized magnet can be manufactured.
  • the mixture used in the calcining step further includes a powder of a compound having Na as a constituent element.
  • a powder of a compound having Na as a constituent element.
  • a mixture containing a powder of an iron compound, a powder of a strontium compound, and a powder of a compound having Li as a constituent element is fired at 850 to 1050 ° C. to form Sr having a hexagonal crystal structure.
  • a calcination step for obtaining a calcined body containing ferrite and containing 0.01 to 0.5% by mass of Li in terms of Li 2 O, and pulverizing to obtain a pulverized powder containing Sr ferrite by crushing the calcined body Sr ferrite sintering comprising: a step, a molding step of forming a pulverized powder in a magnetic field to obtain a molded body, and a sintering step of firing the molded body at 1000 to 1250 ° C. to obtain a Sr ferrite sintered magnet
  • a method for manufacturing a magnet is provided.
  • an Sr ferrite sintered magnet having a high Br can be produced by a simple process.
  • the present inventors infer that this reason is as follows. That is, in the method for producing a sintered Sr ferrite magnet of the present invention, the Sr ferrite sintered magnet is produced using a mixture containing a powder of a compound having Li as a constituent element. This Li has an action of promoting the formation of Sr ferrite, and it is considered that a calcined body having a high saturation magnetization can be obtained at a calcining temperature of 850 to 1050 ° C.
  • the grain growth of Sr ferrite can be sufficiently suppressed. If such a calcined body is pulverized, a sufficiently fine Sr ferrite powder having a high saturation magnetization can be easily obtained.
  • the Sr ferrite powder thus obtained has fine particles, high uniformity, and high saturation magnetization. For this reason, such a sintered Sr ferrite magnet has good sinterability, and an Sr ferrite sintered magnet can be obtained at a low sintering temperature. For this reason, it is considered that during sintering, abnormal grain growth is suppressed, the density is improved while maintaining a sufficiently fine structure, and an Sr ferrite sintered magnet having high Br can be obtained.
  • Li added at the raw material stage is considered to exert an effect of promoting sintering, and this contributes to reduction of the sintering temperature and refinement of the structure of the sintered Sr ferrite magnet. Is also possible.
  • the production method of the present invention is a production method using a mixture obtained by mixing raw material powders, so that Sr ferrite can be produced in a simple process without complicated operations. Sintered magnets can be manufactured. That is, it can be said that the manufacturing method of the Sr ferrite sintered magnet of the present invention is a manufacturing method suitable for mass production of the Sr ferrite sintered magnet.
  • the mixture preferably contains a powder of a compound having Na as a constituent element.
  • the calcination temperature and the sintering temperature can be further lowered, and the structure of the sintered Sr ferrite magnet can be further refined.
  • the present invention provides a motor including a sintered Sr ferrite magnet obtained by the above-described manufacturing method.
  • the motor of the present invention has high efficiency because it includes a sintered Sr ferrite magnet having a high Br.
  • the present invention provides a generator including a sintered Sr ferrite magnet obtained by the above-described manufacturing method. Since the generator of the present invention includes the sintered Sr ferrite magnet having a high Br, the generator has high efficiency.
  • the present invention it is possible to provide a method for producing an Sr ferrite sintered magnet capable of producing an Sr ferrite sintered magnet having a high Br by a simple process. Moreover, the manufacturing method of Sr ferrite powder suitable for manufacturing such a Sr ferrite sintered magnet can be provided. Furthermore, a motor and a generator having high efficiency can be provided by using the Sr ferrite sintered magnet described above.
  • FIG. 3 is an electron micrograph of Sr ferrite powder in Example 1-2. It is sectional drawing which shows typically suitable embodiment of the motor of this invention.
  • FIG. 4 is a sectional view taken along line IV-IV of the motor shown in FIG. 3.
  • the manufacturing method of the Sr ferrite powder of the present embodiment includes an iron compound powder, a strontium compound powder, and a mixing step of preparing a mixture by mixing a compound powder having lithium (Li) as a constituent element, the mixture Is calcined at 850 to 1050 ° C. to obtain a calcined body containing Sr ferrite having a hexagonal crystal structure, and a pulverizing process for crushing the calcined body to obtain Sr ferrite powder.
  • a compound powder having lithium (Li) as a constituent element
  • the mixture Is calcined at 850 to 1050 ° C. to obtain a calcined body containing Sr ferrite having a hexagonal crystal structure
  • a pulverizing process for crushing the calcined body to obtain Sr ferrite powder.
  • the mixing step is a step of preparing a mixture for calcination.
  • the starting materials are weighed and blended at a predetermined ratio, and mixed with a wet attritor or a ball mill for about 1 to 20 hours and pulverized.
  • the starting material include iron compound powder, strontium compound powder, and lithium compound powder having lithium as a constituent element.
  • an oxide or a compound such as carbonate, hydroxide, or nitrate that becomes an oxide by firing can be used.
  • examples of such compounds include SrCO 3 and Fe 2 O 3 .
  • La (OH) 3 and Co 3 O 4 may be added.
  • the lithium compound include oxides, carbonates, silicates, and organic compounds (dispersants) containing lithium.
  • the mixing amount of the lithium compound is such that the lithium content in the mixture obtained in the mixing step is 0.01 to 0.5% by mass, preferably 0.05 to 0.3% by mass in terms of Li 2 O. Mix.
  • the mixing step it is preferable to add a sodium compound having sodium as a constituent element in addition to the above-described lithium compound.
  • a sodium compound having sodium as a constituent element in addition to the above-described lithium compound.
  • the ferrite formation reaction is promoted, and a calcined body containing Sr ferrite can be obtained in a short time even if the calcining temperature in the calcining step is lowered.
  • a calcined body having a higher Sr ferrite content can be obtained.
  • the mixing amount of the sodium compound is such that the sodium content in the mixture obtained in the mixing step is preferably 0.005 to 0.8% by mass, more preferably 0.01 to 0.6% by mass in terms of Na 2 O. Mix to be.
  • Sr ferrite powder having a high saturation magnetization ( ⁇ s ) can be produced in a shorter calcining time.
  • the total content of the lithium compound and sodium compound in the mixture is preferably 0.01 to 1.0% by mass, more preferably 0.02 when the lithium compound and sodium compound are converted to Li 2 O and Na 2 O, respectively. Is 0.5 mass. By setting it as such a range, Sr ferrite powder with high saturation magnetization ((sigma) s ) can be manufactured in a shorter calcination time.
  • the average particle diameter of each starting material is not particularly limited, and is, for example, 0.1 to 2.0 ⁇ m.
  • the specific surface area of each starting material according to the BET method is preferably 2 m 2 / g or more. Thereby, a finer Sr ferrite powder can be obtained.
  • the mixture prepared in the mixing step may be in the form of a powder or may be dispersed in a slurry containing a solvent.
  • the calcining step is a step of calcining the mixture obtained in the mixing step. Calcination can be performed in an oxidizing atmosphere such as air.
  • the firing temperature (calcination temperature) in the calcination step is 850 to 1050 ° C. From the viewpoint of obtaining Sr ferrite powder having high saturation magnetization, the lower limit of the calcining temperature is preferably 900 ° C. On the other hand, from the viewpoint of obtaining sufficiently fine Sr ferrite powder, the upper limit of the calcining temperature is preferably 1000 ° C., more preferably 950 ° C.
  • the calcination time at the calcination temperature is preferably 0.5 to 5 hours, more preferably 1 to 3 hours.
  • the content of Sr ferrite in the calcined body obtained by calcining is preferably 70% by mass or more, and more preferably 90% by mass or more.
  • the mixture used in the calcining step contains a lithium compound, Sr ferrite having a hexagonal crystal structure can be sufficiently generated even at the calcining temperature described above.
  • the saturation magnetization of the calcined body is preferably 67 emu / g or more, more preferably 70 emu / g or more, and further preferably 70.5 emu / g or more.
  • VSM vibrating sample magnetometer
  • the specific surface area of the calcined body by the BET method is preferably 15 m 2 / g or less, more preferably 10 m 2 / g or less, from the viewpoint of improving the moldability when producing a molded body. More preferably, it is 7 m 2 / g or less.
  • the specific surface area in this specification can be measured using a commercially available BET specific surface area measuring apparatus (manufactured by Mountaintech, trade name: HM Model-1210).
  • the calcined body obtained by calcination of the mixture obtained in the mixing step is pulverized to prepare pulverized powder.
  • the pulverization may be performed in one stage, or may be performed in two stages, a coarse pulverization process and a fine pulverization process. Since the calcined body is usually granular or massive, it is preferable to first perform a coarse pulverization step.
  • a coarse pulverized powder is prepared by performing dry pulverization using a vibrating rod mill or the like.
  • the coarsely pulverized powder thus prepared is wet pulverized using a wet attritor, ball mill, jet mill or the like to obtain a finely pulverized powder.
  • the pulverization time is, for example, 30 minutes to 10 hours when using a wet attritor, and 5 to 50 hours when using a ball mill. These times are preferably adjusted appropriately depending on the pulverization method.
  • calcination is performed at a temperature lower than that in the prior art, so the primary particles of Sr ferrite in the calcined body are finer than in the past. Therefore, the pulverization process (particularly the pulverization process) has a strong meaning of dispersing fine primary particles.
  • powders such as SiO 2 , CaCO 3 , SrCO 3, and BaCO 3 that are subcomponents may be added.
  • sinterability can be improved and magnetic properties can be improved.
  • these subcomponents may flow out together with the solvent of the slurry when forming in a wet manner, it is preferable to add more than the target content in the sintered Sr ferrite magnet.
  • polyhydric alcohol in the pulverization step in addition to the above-mentioned subcomponents.
  • the addition amount of the polyhydric alcohol is 0.05 to 5.0% by mass, preferably 0.1 to 3.0% by mass, more preferably 0.3 to 2.0% by mass with respect to the addition target. .
  • the added polyhydric alcohol is thermally decomposed and removed in the sintering process.
  • the specific surface area by the BET method of the pulverized powder obtained in the pulverization step is preferably 6 m 2 / g or more, more preferably 8 m, from the viewpoint of sufficiently finening the structure of the finally obtained Sr ferrite sintered magnet. 2 / g or more.
  • the specific surface area of the pulverized powder by the BET method is preferably 12 m 2 / g or less, more preferably 10 m 2 / g or less, from the viewpoint of improving the moldability when producing a molded body.
  • the structure of the sintered Sr ferrite magnet is further refined while maintaining the simplicity of the process, and the Sr The magnetic properties of the sintered ferrite magnet can be further improved.
  • Sr ferrite powder can be obtained through the above steps. Since the Sr ferrite powder thus obtained is fired using a mixture containing lithium, it is sufficiently fine, has high particle uniformity, and has a high ⁇ s .
  • the content of Sr ferrite having a hexagonal crystal structure in the Sr ferrite powder is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more.
  • the Sr ferrite powder may contain unreacted raw materials such as an iron compound and a strontium compound, a lithium compound, a sodium compound, and other components as components other than the Sr ferrite.
  • Other components include oxides and composite oxides having at least one selected from K (potassium), Si (silicon), Ca (calcium), Sr (strontium) and Ba (barium). Examples of the oxide include K 2 O, SiO 2 , CaO, SrO, and BaO.
  • the saturation magnetization of the Sr ferrite powder is preferably 67 emu / g or more, more preferably 70 emu / g or more, and further preferably 70.5 emu / g or more.
  • the method for producing a sintered Sr ferrite magnet of this embodiment includes a mixing step of preparing a mixture by mixing an iron compound powder, a strontium compound powder, and a compound powder having lithium as a constituent element; Calcining at 850 to 1050 ° C. to obtain a calcined body containing Sr ferrite having a hexagonal crystal structure, crushing process to crush the calcined body to obtain Sr ferrite powder, and Sr ferrite powder in a magnetic field
  • the mixing step, calcination step, and pulverization step are the same as the above-described method for producing Sr ferrite powder.
  • the overlapping process will not be described, and the forming process and the sintering process will be described.
  • the pulverized powder obtained in the pulverization process is molded in a magnetic field to form a molded body.
  • the molding in the magnetic field may be performed by either dry molding or wet molding, and is preferably wet molding from the viewpoint of increasing the degree of magnetic orientation.
  • a slurry can be prepared by blending a pulverized powder and a dispersion medium and pulverizing to prepare a slurry, and a molded product can be produced using the slurry. Concentration of the slurry can be performed by centrifugation, filter press, or the like.
  • the solid content in the slurry is preferably 30 to 85% by mass.
  • water or a non-aqueous solvent can be used as the dispersion medium of the slurry.
  • a surfactant such as gluconic acid, gluconate, or sorbitol may be added to the slurry.
  • molding is performed in a magnetic field to produce a molded body.
  • the molding pressure is, for example, 0.1 to 0.5 ton / cm 2
  • the applied magnetic field is, for example, 5 to 15 kOe.
  • the compact is fired to produce a sintered body.
  • Firing is usually performed in an oxidizing atmosphere such as air.
  • the firing temperature is 1000 to 1250 ° C., preferably 1100 to 1200 ° C.
  • the firing time at the firing temperature is preferably 0.5 to 3 hours.
  • FIG. 1 is a perspective view schematically showing a Sr ferrite sintered magnet obtained by the manufacturing method of the present embodiment.
  • the anisotropic Sr ferrite sintered magnet 10 has a curved shape so that the end surface is arcuate, and generally has a shape called an arc segment shape, a C shape, a tile shape, or an arc shape. is doing.
  • the Sr ferrite sintered magnet 10 is suitably used as a magnet for a motor or a generator, for example.
  • Sr ferrite sintered magnet 10 contains crystal grains of M-type Sr ferrite having a hexagonal crystal structure as a main component.
  • Sr ferrite is represented by the following formula (1), for example. SrFe 12 O 19 (1)
  • Sr at the A site and Fe at the B site may be partially substituted by impurities or intentionally added elements. Further, the ratio between the A site and the B site may be slightly shifted.
  • the Sr ferrite can be expressed by, for example, the following general formula (2).
  • x and y are, for example, 0.1 to 0.5
  • z is 0.7 to 1.2.
  • M in the general formula (2) is, for example, one or more selected from the group consisting of Co (cobalt), Zn (zinc), Ni (nickel), Mn (manganese), Al (aluminum), and Cr (chromium). It is an element.
  • R in the general formula (3) is, for example, one or more elements selected from the group consisting of La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), and Sm (samarium). .
  • the ratio of the Sr ferrite phase in the sintered Sr ferrite magnet 10 is preferably 95% or more, more preferably 97% or more, and further preferably 99% or more.
  • the ratio of Sr ferrite phase in Sr ferrite sintered magnet 10 (%) is the theoretical value of the saturation magnetization of the Sr ferrite sigma t, when the actually measured values ⁇ s, ( ⁇ s / ⁇ t) ⁇ 100 formula Can be obtained.
  • the Sr ferrite sintered magnet 10 contains a component different from Sr ferrite as a subcomponent.
  • the subcomponent include alkali metal compounds having Li (lithium) and / or Na (sodium) as constituent elements.
  • the alkali metal compound include oxides such as Li 2 O and Na 2 O and silicate glass.
  • the Li content in the sintered Sr ferrite magnet 10 is 0.01 to 0.5% by mass, preferably 0.01 to 0.3% by mass in terms of Li 2 O.
  • the content of Na in the sintered Sr ferrite magnet 10 is 0.01 to 0.2% by mass in terms of Na 2 O.
  • the total content of Li and Na in the Sr ferrite sintered magnet 10 is 0.02 to 0.5 mass% when Li and Na are converted to Li 2 O and Na 2 O, respectively.
  • the content of Li and / or Na in the Sr ferrite sintered magnet 10 becomes excessive, white powder tends to be generated on the surface.
  • the content of Li and / or Na in the Sr ferrite sintered magnet 10 becomes too small, the time required for sintering tends to become longer.
  • the Sr ferrite sintered magnet 10 may contain an arbitrary component in addition to the above-described alkali metal compound as a subcomponent.
  • examples of such components include oxides and composite oxides having at least one selected from K (potassium), Si (silicon), Ca (calcium), Sr (strontium), and Ba (barium).
  • examples of the oxide include K 2 O, SiO 2 , CaO, SrO, and BaO.
  • the Si content in the sintered Sr ferrite magnet 10 is, for example, 0.1 to 1.0 mass% in terms of SiO 2 .
  • the Sr content in the sintered Sr ferrite magnet 10 is, for example, 10 to 13% by mass in terms of SrO.
  • the Sr ferrite sintered magnet 10 may contain Ba.
  • the Ba content in the sintered Sr ferrite magnet 10 is, for example, 0.01 to 2.0 mass% in terms of BaO.
  • the Ca content in the sintered Sr ferrite magnet 10 is, for example, 0.05 to 2% by mass in terms of CaO.
  • the Sr ferrite sintered magnet 10 may contain impurities contained in the raw materials and inevitable components derived from the manufacturing equipment. Examples of such components include Ti (titanium), Cr (chromium), Mn (manganese), Mo (molybdenum), V (vanadium), and Al (aluminum) oxides.
  • the subcomponents are mainly contained in the grain boundaries of the Sr ferrite crystal grains in the Sr ferrite sintered magnet 10.
  • the content of each component of the sintered Sr ferrite magnet 10 can be measured by fluorescent X-ray analysis and inductively coupled plasma emission spectroscopic analysis (ICP analysis).
  • Sr ferrite sintered magnet 10 is, for example, for fuel pump, power window, ABS (anti-lock brake system), fan, wiper, power steering, active suspension, starter, door lock, It can be used as a magnet for an automobile motor such as an electric mirror. Also for FDD spindle, VTR capstan, VTR rotary head, VTR reel, VTR loading, VTR camera capstan, VTR camera rotary head, VTR camera zoom, VTR camera focus, radio cassette etc. It can be used as a magnet for motors for OA / AV devices such as CD / DVD / MD spindle, CD / DVD / MD loading, and CD / DVD optical pickup.
  • OA / AV devices such as CD / DVD / MD spindle, CD / DVD / MD loading, and CD / DVD optical pickup.
  • a magnet for a motor for home appliances such as an air conditioner compressor, a freezer compressor, an electric tool drive, a dryer fan, a shaver drive, an electric toothbrush and the like.
  • a magnet for a motor for FA equipment such as a robot shaft, joint drive, robot main drive, machine tool table drive, machine tool belt drive and the like.
  • the Sr ferrite sintered magnet 10 is attached to the above-mentioned motor member and installed in the motor. Since the Sr ferrite sintered magnet 10 has high Br, various motors including the Sr ferrite sintered magnet 10 have high efficiency.
  • FIG. 3 is a cross-sectional view schematically showing an embodiment of the motor 30 including the Sr ferrite sintered magnet 10.
  • the motor 30 of the present embodiment is a DC motor with a brush, and includes a bottomed cylindrical housing 31 (stator) and a rotatable rotor 32 disposed concentrically on the inner peripheral side of the housing 31.
  • the rotor 32 includes a rotor shaft 36 and a rotor core 37 fixed on the rotor shaft 36.
  • a bracket 33 is fitted in the opening of the housing 31, and the rotor core is accommodated in a space formed by the housing 31 and the bracket 33.
  • the rotor shaft 36 is rotatably supported by bearings 34 and 35 provided at the center portion of the housing 31 and the center portion of the bracket 33 so as to face each other.
  • Two C-type Sr ferrite sintered magnets 10 are fixed to the inner peripheral surface of the cylindrical portion of the housing 31 so as to face each other.
  • FIG. 4 is a cross-sectional view taken along line IV-IV of the motor 30 in FIG.
  • the Sr ferrite sintered magnet 10 that is a motor magnet is bonded to the inner peripheral surface of the housing 31 with an adhesive, with the outer peripheral surface serving as an adhesive surface. Since the Sr ferrite sintered magnet 10 has sufficiently suppressed the precipitation of foreign substances such as powder on the surface, the adhesion between the housing 31 and the Sr ferrite sintered magnet 10 is good. Therefore, the motor 30 has excellent reliability as well as excellent characteristics.
  • sintered Sr ferrite magnet 10 are not limited to motors and generators.
  • the shape of the Sr ferrite sintered magnet is not limited to the shape shown in FIG. 1 and can be appropriately changed to a shape suitable for each application described above.
  • the calcined body is pulverized to obtain Sr ferrite powder.
  • the Sr ferrite powder obtained by the production method of the present invention may be a calcined body that has not been pulverized.
  • the above-mentioned Fe 2 O 3 powder and SrCO 3 powder were mixed while being pulverized for 16 hours using a wet ball mill to obtain a slurry.
  • a slurry was added lithium carbonate powder.
  • the addition amount at this time was set to 0.19% by mass in terms of Li 2 O with respect to the total mass of the Fe 2 O 3 powder and the SrCO 3 powder.
  • the slurry was spray-dried to obtain a granular mixture having a particle size of about 10 ⁇ m.
  • the mixture was fired in the air at a calcining temperature T 1 (800 to 1100 ° C.) shown in Table 1 for 1 hour to obtain a granular calcined body containing Sr ferrite having a hexagonal crystal structure.
  • the magnetic properties (saturation magnetization and coercive force) of the obtained calcined body were measured using a commercially available vibrating sample magnetometer (VSM).
  • VSM vibrating sample magnetometer
  • the measurement method was as follows. Magnetization ( ⁇ ) in a magnetic field (Hex) of 16 kOe to 19 kOe was measured by VSM (manufactured by Toei Kogyo Co., Ltd., trade name: VSM-3 type). Then, the value of ⁇ ( ⁇ s ) when Hex is infinite was calculated by the saturation asymptotic rule. That is, ⁇ was plotted against 1 / Hex 2 and linear approximation was performed, and a value obtained by extrapolating 1 / Hex 2 ⁇ 0 was obtained. The correlation coefficient at this time was 99% or more. Moreover, the specific surface area by BET method of the obtained calcined body was measured. These measurement results are summarized in Table 1.
  • the Li 2 O equivalent content of Li in the obtained calcined body was measured using a commercially available ICP analyzer. As a result, the Li content in terms of Li 2 O in Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-2 was 0.19% by mass.
  • FIG. 2 is an electron micrograph of pulverized powder (Sr ferrite powder) obtained by wet pulverizing the calcined body of Example 1-2 with a ball mill. This pulverized powder did not contain coarse particles having a particle size of 1 ⁇ m or more.
  • Example 2-1 to Example 2-3 A granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained in the same manner as in Example 1-2 (T 1 : 900 ° C.). The content of Li in terms of Li 2 O in the obtained calcined body was measured in the same manner as in Examples 1-1 to 1-5. As a result, the Li content in terms of Li 2 O was 0.18% by mass.
  • Sorbitol, SiO 2 powder and CaCO 3 powder were added to 130 g of this calcined body.
  • the amount of each additive was 1% by mass of sorbitol, 0.6% by mass of SiO 2 powder, and 1.4% by mass of CaCO 3 powder based on the calcined body.
  • the calcined body was wet-ground for 22 hours using a ball mill to obtain a slurry.
  • the specific surface area of the Sr ferrite powder by the BET method of the pulverized powder after the wet pulverization was 12 m 2 / g.
  • the magnetic properties were measured using a BH tracer with a maximum applied magnetic field of 25 kOe.
  • HcJ, Br, and 4PI max were obtained, and the degree of orientation (Br / 4PI max ) was calculated.
  • the density of the sintered Sr ferrite magnet and the content of Li in terms of Li 2 O were measured by Archimedes method and fluorescent X-ray analysis, respectively. These results are shown in Table 5.
  • the method for measuring the Li content in the sintered Sr ferrite magnet is the same as in Example 1-1, and the numerical values in Table 5 are the contents in terms of Li 2 O.
  • Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used.
  • the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g.
  • Sintering temperature T 2 of each of the comparative examples are as shown in Table 5.
  • the magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. Table 5 shows the measurement results.
  • Comparative Example 2-4 to Comparative Example 2-6 In the same manner as in Comparative Example 1-12 (T 1 : 900 ° C.), a granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 2-1 to 2-3. As a result, ⁇ : 55.9 emu / g and HcJ: 1985 Oe.
  • Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used.
  • the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g.
  • Sintering temperature T 2 of each of the comparative examples are as shown in Table 5.
  • the magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. These results are shown in Table 5.
  • Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used.
  • the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g.
  • Sintering temperature T 2 of each of the comparative examples are as shown in Table 5.
  • the magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. These results are shown in Table 5.
  • the sintered Sr ferrite magnets of Examples 2-1 to 2-3 had higher density, higher Br, and higher degree of orientation than those of the comparative examples without extremely decreasing HcJ. This is because the Sr ferrite powder having a fine and high ⁇ s obtained by adding Li in advance before calcination is used, so that the sintering is promoted to have such a high density and a high Br. It shows that an Sr ferrite sintered magnet was obtained.
  • the above-mentioned Fe 2 O 3 powder and SrCO 3 powder were mixed while being pulverized for 16 hours using a wet ball mill to obtain a slurry.
  • sodium silicate powder and lithium carbonate powder were added.
  • the addition amount of the sodium silicate powder and the lithium carbonate powder at this time is 0.38% by mass in terms of Na 2 O and Li 2 O, respectively, with respect to the total mass of the Fe 2 O 3 powder and the SrCO 3 powder. It was set to 0.09 mass%.
  • the slurry was spray-dried to obtain a granular mixture having a particle size of about 10 ⁇ m.
  • the mixture was fired in the air at a calcining temperature T 1 (800 to 950 ° C.) shown in Table 6 for 1 hour to obtain a granular calcined body containing Sr ferrite having a hexagonal crystal structure.
  • Example 4-1 to Example 4-6 [Production and Evaluation of Sr Ferrite Sintered Magnet 2] (Example 4-1 to Example 4-6) In the same manner as in Example 3-1 (T 1 : 850 ° C.), a granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained. Sorbitol, SiO 2 powder and CaCO 3 powder were added to 130 g of this calcined body. The amount of each additive was 1% by mass of sorbitol, 0.4% by mass of SiO 2 powder, and 0.9% by mass of CaCO 3 powder based on the calcined body. After adding these additives, the calcined body was wet-ground using a ball mill to obtain a slurry. Table 8 shows the wet pulverization time and the specific surface area of the Sr ferrite powder by the BET method after the wet pulverization.
  • the present invention it is possible to provide a method for producing an Sr ferrite sintered magnet capable of producing an Sr ferrite sintered magnet having a high Br by a simple process.
  • a sintered Sr ferrite magnet having high magnetic properties and high reliability can be provided.
  • a motor and a generator having high efficiency and high reliability can be provided.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Magnetic Ceramics (AREA)
  • Hard Magnetic Materials (AREA)
  • Manufacturing Cores, Coils, And Magnets (AREA)
  • Compounds Of Iron (AREA)

Abstract

Provided is a method for manufacturing an Sr ferrite sintered magnet, the method having: a quasi-sintering step for sintering a mixture that contains a powdered iron compound, a powdered strontium compound, and a powdered compound having Li as a constituent element at 850-1050°C to obtain a quasi-sintered body containing Sr ferrite having a hexagonal crystal structure, and containing 0.01-0.5 mass% of Li in terms of Li2O; a pulverizing step for pulverizing the quasi-sintered body to obtain a pulverized powder containing Sr ferrite; and a sintering step for sintering a molded body, obtained by molding the pulverized powder in a magnetic field, at 1000-1250°C to obtain the Sr ferrite sintered magnet.

Description

Ｓｒフェライト粉末及びＳｒフェライト焼結磁石の製造方法、並びにモータ及び発電機Method for producing Sr ferrite powder and sintered Sr ferrite magnet, motor and generator
　本発明は、Ｓｒフェライト粉末及びＳｒフェライト焼結磁石の製造方法、並びに、当該製造方法によって得られるＳｒフェライト焼結磁石を備えるモータ及び発電機に関する。 The present invention relates to a method for producing Sr ferrite powder and a sintered Sr ferrite magnet, and a motor and a generator including the Sr ferrite sintered magnet obtained by the production method.
　フェライト焼結磁石に用いられる磁性材料として、六方晶系の結晶構造を有するＢａフェライト、Ｓｒフェライト及びＣａフェライトが知られている。近年、これらの中でも、モータ用等の磁石材料として、主にマグネトプランバイト型（Ｍ型）のＳｒフェライトが採用されている。Ｍ型フェライトは例えばＡＦｅ１２Ｏ１９の一般式で表される。Ｓｒフェライトは、結晶構造のＡサイトにＳｒを有する。 As a magnetic material used for a ferrite sintered magnet, Ba ferrite, Sr ferrite, and Ca ferrite having a hexagonal crystal structure are known. In recent years, among them, magnetoplumbite type (M type) Sr ferrite is mainly used as a magnet material for motors and the like. The M-type ferrite is represented by a general formula of AFe 12 O 19 , for example. Sr ferrite has Sr at the A site of the crystal structure.
　Ｓｒフェライト焼結磁石の磁気特性を改善するために、Ａサイトの元素及びＢサイトの元素の一部を、それぞれＬａ等の希土類元素及びＣｏで置換することによって、磁気特性を改善することが試みられている。例えば、特許文献１では、Ａサイト及びＢサイトの一部を特定量の希土類元素及びＣｏで置換することによって、残留磁束密度（Ｂｒ）及び保磁力（ＨｃＪ）を向上する技術が開示されている。 In order to improve the magnetic properties of sintered Sr ferrite magnets, attempts were made to improve the magnetic properties by substituting some elements of the A site and B site with rare earth elements such as La and Co, respectively. It has been. For example, Patent Document 1 discloses a technique for improving the residual magnetic flux density (Br) and the coercive force (HcJ) by replacing a part of the A site and the B site with a specific amount of rare earth element and Co. .
　Ｓｒフェライト焼結磁石の代表的な用途としては、モータ及び発電機が挙げられる。モータや発電機に用いられるＳｒフェライト磁石は、小型化及び軽量化することが求められており、これに対応するために、一層磁気特性を高くすることが要請されている。 Typical applications of sintered Sr ferrite magnets include motors and generators. Sr ferrite magnets used in motors and generators are required to be reduced in size and weight, and in order to cope with this, it is required to further increase the magnetic characteristics.
特開平１１－１５４６０４号公報Japanese Patent Laid-Open No. 11-154604
　上記特許文献１に示されるように、Ｓｒフェライト焼結磁石を構成する主な結晶粒の組成を制御して磁気特性を改善することは有効である。しかしながら、結晶粒の組成のみを制御しても、従来のＳｒフェライト焼結磁石の磁気特性を大きく改善することは難しい。Ｓｒフェライト焼結磁石の磁気特性を向上する別の手段としては、組織を微細化することが考えられる。組織を微細化する手段としては、Ｓｒフェライト焼結磁石の原料として用いられる仮焼体を微粒化することが考えられる。仮焼体を微粒化する方法としては、仮焼体を機械的に微細に粉砕する方法や粉砕時間を長くすることが挙げられるものの、このように機械的に細かく粉砕すると、粒度分布が広くなること、消費電力の増大や設備の摩耗などにより製造コストが増大すること、及び歩留まりが低下すること等が懸念される。 As shown in the above-mentioned Patent Document 1, it is effective to improve the magnetic characteristics by controlling the composition of main crystal grains constituting the Sr ferrite sintered magnet. However, even if only the composition of the crystal grains is controlled, it is difficult to greatly improve the magnetic characteristics of the conventional Sr ferrite sintered magnet. As another means for improving the magnetic characteristics of the Sr ferrite sintered magnet, it is conceivable to refine the structure. As a means for refining the structure, it can be considered that the calcined body used as a raw material of the sintered Sr ferrite magnet is atomized. As a method for atomizing the calcined body, a method of mechanically crushing the calcined body and lengthening the crushing time can be mentioned. However, when the mechanically pulverized in this way, the particle size distribution becomes wide. In addition, there are concerns that the manufacturing cost increases due to increased power consumption, equipment wear, and the like, and the yield decreases.
　Ｓｒフェライト焼結磁石は、ｃ軸方向に結晶配向させた、異方性のＳｒフェライト焼結磁石が現在主流となっている。異方性のＳｒフェライト焼結磁石を製造する場合、成形体を作製する段階でフェライト粒子の磁場による配向性を高めるために、仮焼工程で十分にフェライト化反応を進行させておく必要がある。このため、一般的には１２５０℃以上の高い温度で仮焼及び焼成が行われていた。その結果、仮焼工程及び焼成工程におけるエネルギーコストが増大するとともに、フェライト粒子も数μｍ～数十μｍに粒成長していた。Ｓｒフェライト焼結磁石の磁気特性を向上させるために、このように粒成長したフェライト粒子を１μｍ以下に均一に微細化することは困難である。また、仮焼体を粉砕するためのコストも増大することが懸念される。 As for Sr ferrite sintered magnets, anisotropic Sr ferrite sintered magnets whose crystal orientation is in the c-axis direction are currently mainstream. When an anisotropic Sr ferrite sintered magnet is manufactured, it is necessary to advance the ferritization reaction sufficiently in the calcining step in order to increase the orientation of the ferrite particles by the magnetic field at the stage of forming the molded body. . For this reason, calcination and baking were generally performed at a high temperature of 1250 ° C. or higher. As a result, energy costs in the calcination step and the firing step increased, and ferrite particles grew to several μm to several tens of μm. In order to improve the magnetic properties of the Sr ferrite sintered magnet, it is difficult to uniformly refine the ferrite particles thus grown to 1 μm or less. Moreover, there is a concern that the cost for pulverizing the calcined body also increases.
　微細なＳｒフェライト粉末を得る方法としては、共沈法や融剤を添加するフラックス法などがあるが、これらの方法でＳｒフェライト粉末を製造する場合、フラックスを洗浄する工程又は溶液を調製する等の面倒な操作が必要となり、工程が複雑になり製造コストが増大する。このような状況の下、高い磁気特性を有するＳｒフェライト焼結磁石を簡便な工程で、低い製造コストで作製することが可能な製造方法を確立することが求められている。 As a method for obtaining a fine Sr ferrite powder, there are a coprecipitation method and a flux method in which a flux is added. When producing Sr ferrite powder by these methods, a step of cleaning the flux or preparing a solution, etc. This requires complicated operations, which complicates the process and increases the manufacturing cost. Under such circumstances, it is required to establish a production method capable of producing an Sr ferrite sintered magnet having high magnetic properties by a simple process at a low production cost.
　一方で、Ｓｒフェライト焼結磁石をモータや発電機に使用する場合、モータのトルクや発電機の効率を向上させるためには、Ｓｒフェライト焼結磁石の磁束密度を高める必要がある。このため、高いＢｒ（飽和磁束密度）を有するＳｒフェライト焼結磁石が求められている。 On the other hand, when the Sr ferrite sintered magnet is used for a motor or a generator, it is necessary to increase the magnetic flux density of the Sr ferrite sintered magnet in order to improve the torque of the motor or the efficiency of the generator. For this reason, a sintered Sr ferrite magnet having a high Br (saturation magnetic flux density) is required.
　本発明は上記事情に鑑みてなされたものであり、高いＢｒを有するＳｒフェライト焼結磁石を、簡便な工程で製造することが可能なＳｒフェライト焼結磁石の製造方法を提供することを目的とする。また、このようなＳｒフェライト焼結磁石の製造方法に適したＳｒフェライト粉末の製造方法を提供することを目的とする。さらに、上述のＳｒフェライト焼結磁石を用いることによって、高い効率を有するモータ及び発電機を提供することを目的とする。 This invention is made | formed in view of the said situation, and it aims at providing the manufacturing method of the Sr ferrite sintered magnet which can manufacture the Sr ferrite sintered magnet which has high Br by a simple process. To do. Moreover, it aims at providing the manufacturing method of Sr ferrite powder suitable for the manufacturing method of such a Sr ferrite sintered magnet. Furthermore, it aims at providing the motor and generator which have high efficiency by using the above-mentioned Sr ferrite sintered magnet.
　本発明者らは、Ｓｒフェライト焼結磁石の組織を微細化するため、原料として用いるＳｒフェライト粉末の製造方法を種々検討した。その結果、構成元素としてＬｉを有する化合物を添加することによって、Ｓｒフェライトが生成する温度を大幅に低減できることを見出した。そして、低い温度で仮焼して得られたＳｒフェライト粉末を用いることによって、高いＢｒを有するＳｒフェライト焼結磁石を製造できることを見出し、本発明を完成するに至った。 The present inventors have studied various methods for producing Sr ferrite powder used as a raw material in order to refine the structure of the sintered Sr ferrite magnet. As a result, it has been found that the temperature at which Sr ferrite is generated can be significantly reduced by adding a compound having Li as a constituent element. And it discovered that the Sr ferrite sintered magnet which has high Br can be manufactured by using Sr ferrite powder obtained by calcining at low temperature, and came to complete this invention.
　すなわち、本発明は、一つの側面において、鉄化合物の粉末、ストロンチウム化合物の粉末、及び、構成元素としてＬｉを有する化合物の粉末を含む混合物を、８５０～１０５０℃で焼成して、六方晶構造を有するＳｒフェライトを含み、ＬｉをＬｉ２Ｏに換算して０．０１～０．５質量％含有する仮焼体を得る仮焼工程を有する、仮焼体又はその粉砕粉を含むＳｒフェライト粉末の製造方法を提供する。 That is, according to one aspect of the present invention, a mixture containing an iron compound powder, a strontium compound powder, and a compound powder containing Li as a constituent element is fired at 850 to 1050 ° C. to obtain a hexagonal crystal structure. Of a Sr ferrite powder including a calcined body or a pulverized powder thereof having a calcined step of obtaining a calcined body containing 0.01 to 0.5% by mass of Li in terms of Li 2 O A manufacturing method is provided.
　上述のＳｒフェライト粉末の製造方法によれば、高い飽和磁化（σｓ）を有する微細なＳｒフェライト粉末を簡便に得ることができる。本発明者らは、この理由は次のとおり推察している。すなわち、本発明のＳｒフェライト粉末の製造方法では、Ｓｒフェライト粉末を製造するための原料として、構成元素としてＬｉを有する化合物の粉末を含む混合物を用いている。このＬｉがＳｒフェライトの生成を促進する作用を有しており、これによって、８００～１０５０℃の仮焼温度でＳｒフェライトが生成して飽和磁化が高い仮焼体を得ることができると考えている。上述の仮焼温度は、従来の一般的な仮焼温度よりも低いことから、Ｓｒフェライトの粒成長を十分に抑制することができる。このような仮焼体を必要に応じて粉砕すれば、十分に微細で高い飽和磁化を有するＳｒフェライト粉末を簡便に得ることができる。このようにして得られるＳｒフェライト粉末は、粒子が微細で且つ均一性が高いうえに、高い飽和磁化を有していることから、高いＢｒを有することが求められるＳｒフェライト焼結磁石を製造するための原料として特に好適に用いることができる。 According to the method for producing Sr ferrite powder described above, a fine Sr ferrite powder having high saturation magnetization (σ s ) can be easily obtained. The present inventors presume this reason as follows. That is, in the method for producing Sr ferrite powder of the present invention, a mixture containing a powder of a compound having Li as a constituent element is used as a raw material for producing Sr ferrite powder. It is believed that this Li has the action of promoting the formation of Sr ferrite, and as a result, it is possible to obtain a calcined body having a high saturation magnetization by forming Sr ferrite at a calcining temperature of 800 to 1050 ° C. Yes. Since the above calcination temperature is lower than the conventional general calcination temperature, the grain growth of Sr ferrite can be sufficiently suppressed. If such a calcined body is pulverized as necessary, a sufficiently fine Sr ferrite powder having high saturation magnetization can be easily obtained. The Sr ferrite powder obtained in this way produces Sr ferrite sintered magnets that are required to have high Br because the particles are fine and have high uniformity and also have high saturation magnetization. It can be particularly suitably used as a raw material for the purpose.
　上記本発明のＳｒフェライト粉末の製造方法は、仮焼体を粉砕してＳｒフェライトを含む粉砕粉を得る粉砕工程を有することが好ましい。これによって、焼結性に優れるＳｒフェライト粉末を一層簡便な方法で製造することができる。 The method for producing Sr ferrite powder of the present invention preferably includes a pulverization step of pulverizing the calcined body to obtain a pulverized powder containing Sr ferrite. Thereby, the Sr ferrite powder excellent in sinterability can be produced by a simpler method.
　仮焼工程で得られる仮焼体のＢＥＴ法による比表面積は、２ｍ２／ｇ以上であり、飽和磁化が６７ｅｍｕ／ｇ以上であることが好ましい。このような仮焼体は、一層微細であるうえに高い飽和磁化を有する。このため、この仮焼体又はその粉砕粉を含むＳｒフェライト粉末を焼結してＳｒフェライト焼結磁石を製造する際に、焼結温度を低くしても、十分に高いＢｒを有するＳｒフェライト焼結磁石を製造することができる。 The specific surface area by the BET method of the calcined body obtained in the calcining step is preferably 2 m 2 / g or more and the saturation magnetization is 67 emu / g or more. Such a calcined body is finer and has a high saturation magnetization. For this reason, when the Sr ferrite powder containing this calcined body or its pulverized powder is sintered to produce a Sr ferrite sintered magnet, even if the sintering temperature is lowered, Sr ferrite sintered having a sufficiently high Br is obtained. A magnetized magnet can be manufactured.
　仮焼工程で用いられる混合物は、さらに、構成元素としてＮａを有する化合物の粉末を含むことが好ましい。このように、混合物において、ＬｉとＮａとを共存させることによって、フェライト化反応を一層促進することが可能となる。このため、仮焼温度を一層低くすることができる。 It is preferable that the mixture used in the calcining step further includes a powder of a compound having Na as a constituent element. Thus, it becomes possible to further promote the ferritization reaction by allowing Li and Na to coexist in the mixture. For this reason, the calcination temperature can be further lowered.
　本発明は、別の側面において、鉄化合物の粉末、ストロンチウム化合物の粉末、及び、構成元素としてＬｉを有する化合物の粉末を含む混合物を、８５０～１０５０℃で焼成して、六方晶構造を有するＳｒフェライトを含み、ＬｉをＬｉ２Ｏに換算して０．０１～０．５質量％含有する仮焼体を得る仮焼工程と、仮焼体を粉砕してＳｒフェライトを含む粉砕粉を得る粉砕工程と、粉砕粉を磁場中成形して成形体を得る成形工程と、成形体を１０００～１２５０℃で焼成して、Ｓｒフェライト焼結磁石を得る焼結工程と、を有する、Ｓｒフェライト焼結磁石の製造方法を提供する。 In another aspect of the present invention, a mixture containing a powder of an iron compound, a powder of a strontium compound, and a powder of a compound having Li as a constituent element is fired at 850 to 1050 ° C. to form Sr having a hexagonal crystal structure. A calcination step for obtaining a calcined body containing ferrite and containing 0.01 to 0.5% by mass of Li in terms of Li 2 O, and pulverizing to obtain a pulverized powder containing Sr ferrite by crushing the calcined body Sr ferrite sintering comprising: a step, a molding step of forming a pulverized powder in a magnetic field to obtain a molded body, and a sintering step of firing the molded body at 1000 to 1250 ° C. to obtain a Sr ferrite sintered magnet A method for manufacturing a magnet is provided.
　上述のＳｒフェライト焼結磁石の製造方法によれば、高いＢｒを有するＳｒフェライト焼結磁石を簡便な工程で製造することができる。本発明者らは、この理由は次のとおりと推察している。すなわち、本発明のＳｒフェライト焼結磁石の製造方法では、構成元素としてＬｉを有する化合物の粉末を含む混合物を用いて製造している。このＬｉがＳｒフェライトの生成を促進する作用を有しており、これによって、８５０～１０５０℃の仮焼温度で飽和磁化が高い仮焼体を得ることができると考えている。上述の仮焼温度は、従来の一般的な仮焼温度よりも低いことから、Ｓｒフェライトの粒成長を十分に抑制することができる。このような仮焼体を粉砕すれば、十分に微細で飽和磁化が高いＳｒフェライト粉末を簡便に得ることができる。 According to the method for producing a sintered Sr ferrite magnet described above, an Sr ferrite sintered magnet having a high Br can be produced by a simple process. The present inventors infer that this reason is as follows. That is, in the method for producing a sintered Sr ferrite magnet of the present invention, the Sr ferrite sintered magnet is produced using a mixture containing a powder of a compound having Li as a constituent element. This Li has an action of promoting the formation of Sr ferrite, and it is considered that a calcined body having a high saturation magnetization can be obtained at a calcining temperature of 850 to 1050 ° C. Since the above calcination temperature is lower than the conventional general calcination temperature, the grain growth of Sr ferrite can be sufficiently suppressed. If such a calcined body is pulverized, a sufficiently fine Sr ferrite powder having a high saturation magnetization can be easily obtained.
　このようにして得られるＳｒフェライト粉末は、粒子が微細で且つ均一性が高いうえに、高い飽和磁化を有している。このため、このようなＳｒフェライト焼結磁石は焼結性がよく、Ｓｒフェライト焼結磁石を低い焼結温度で得ることができる。このため、焼結時において、異常粒成長が抑制され、十分に微細な組織を維持しつつ密度が向上して、高いＢｒを有するＳｒフェライト焼結磁石が得られると考えられる。なお、原料段階で添加されているＬｉは、焼結促進の作用を発揮していることも考えられ、これが焼結温度の低減及びＳｒフェライト焼結磁石の組織の微細化に寄与していることも考えられる。 The Sr ferrite powder thus obtained has fine particles, high uniformity, and high saturation magnetization. For this reason, such a sintered Sr ferrite magnet has good sinterability, and an Sr ferrite sintered magnet can be obtained at a low sintering temperature. For this reason, it is considered that during sintering, abnormal grain growth is suppressed, the density is improved while maintaining a sufficiently fine structure, and an Sr ferrite sintered magnet having high Br can be obtained. In addition, Li added at the raw material stage is considered to exert an effect of promoting sintering, and this contributes to reduction of the sintering temperature and refinement of the structure of the sintered Sr ferrite magnet. Is also possible.
　本発明の製造方法では、共沈法やフラックス法とは異なり、原料粉末を混合して得られる混合物を用いた製造方法であることから、煩雑な操作を行ことなく、簡便な工程でＳｒフェライト焼結磁石を製造することができる。すなわち、本発明のＳｒフェライト焼結磁石の製造方法は、Ｓｒフェライト焼結磁石の量産に適した製造方法であるといえる。 Unlike the coprecipitation method and the flux method, the production method of the present invention is a production method using a mixture obtained by mixing raw material powders, so that Sr ferrite can be produced in a simple process without complicated operations. Sintered magnets can be manufactured. That is, it can be said that the manufacturing method of the Sr ferrite sintered magnet of the present invention is a manufacturing method suitable for mass production of the Sr ferrite sintered magnet.
　本発明の製造方法では、混合物が、構成元素としてＮａを有する化合物の粉末を含むことが好ましい。このように、混合物において、ＬｉとＮａとを共存させることによって、フェライト化反応を一層促進することが可能となる。これによって、仮焼温度及び焼結温度を一層低くすることが可能となり、Ｓｒフェライト焼結磁石の組織の一層の微細化を図ることができる。 In the production method of the present invention, the mixture preferably contains a powder of a compound having Na as a constituent element. Thus, it becomes possible to further promote the ferritization reaction by allowing Li and Na to coexist in the mixture. As a result, the calcination temperature and the sintering temperature can be further lowered, and the structure of the sintered Sr ferrite magnet can be further refined.
　本発明は、さらに別の側面において、上述の製造方法によって得られるＳｒフェライト焼結磁石を備えるモータを提供する。本発明のモータは、高いＢｒを有するＳｒフェライト焼結磁石を備えることから高い効率を有する。 In still another aspect, the present invention provides a motor including a sintered Sr ferrite magnet obtained by the above-described manufacturing method. The motor of the present invention has high efficiency because it includes a sintered Sr ferrite magnet having a high Br.
　本発明は、さらに別の側面において、上述の製造方法によって得られるＳｒフェライト焼結磁石を備える発電機を提供する。本発明の発電機は、高いＢｒを有するＳｒフェライト焼結磁石を備えることから、高い効率を有する。 In still another aspect, the present invention provides a generator including a sintered Sr ferrite magnet obtained by the above-described manufacturing method. Since the generator of the present invention includes the sintered Sr ferrite magnet having a high Br, the generator has high efficiency.
　本発明によれば、高いＢｒを有するＳｒフェライト焼結磁石を、簡便な工程で製造することが可能なＳｒフェライト焼結磁石の製造方法を提供することができる。また、このようなＳｒフェライト焼結磁石を製造するのに適したＳｒフェライト粉末の製造方法を提供することができる。さらに、上述のＳｒフェライト焼結磁石を用いることによって、高い効率を有するモータ及び発電機を提供することができる。 According to the present invention, it is possible to provide a method for producing an Sr ferrite sintered magnet capable of producing an Sr ferrite sintered magnet having a high Br by a simple process. Moreover, the manufacturing method of Sr ferrite powder suitable for manufacturing such a Sr ferrite sintered magnet can be provided. Furthermore, a motor and a generator having high efficiency can be provided by using the Sr ferrite sintered magnet described above.
本発明の製造方法の一実施形態で得られるＳｒフェライト焼結磁石を模式的に示す斜視図である。It is a perspective view which shows typically the Sr ferrite sintered magnet obtained by one Embodiment of the manufacturing method of this invention. 実施例１－２におけるＳｒフェライト粉末の電子顕微鏡写真である。3 is an electron micrograph of Sr ferrite powder in Example 1-2. 本発明のモータの好適な実施形態を模式的に示す断面図である。It is sectional drawing which shows typically suitable embodiment of the motor of this invention. 図３に示すモータのＩＶ－ＩＶ線断面図である。FIG. 4 is a sectional view taken along line IV-IV of the motor shown in FIG. 3.
　以下、必要に応じて図面を参照しつつ、本発明の好適な実施形態について詳細に説明する。 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary.
　本発明のＳｒフェライト粉末の製造方法の好適な実施形態を説明する。本実施形態のＳｒフェライト粉末の製造方法は、鉄化合物の粉末、ストロンチウム化合物の粉末、並びに、構成元素としてリチウム（Ｌｉ）を有する化合物の粉末を混合して混合物を調製する混合工程と、該混合物を８５０～１０５０℃で焼成して、六方晶構造を有するＳｒフェライトを含む仮焼体を得る仮焼工程と、仮焼体を粉砕してＳｒフェライト粉末を得る粉砕工程と、を有する。以下、各工程の詳細を説明する。 A preferred embodiment of the method for producing Sr ferrite powder of the present invention will be described. The manufacturing method of the Sr ferrite powder of the present embodiment includes an iron compound powder, a strontium compound powder, and a mixing step of preparing a mixture by mixing a compound powder having lithium (Li) as a constituent element, the mixture Is calcined at 850 to 1050 ° C. to obtain a calcined body containing Sr ferrite having a hexagonal crystal structure, and a pulverizing process for crushing the calcined body to obtain Sr ferrite powder. Hereinafter, details of each process will be described.
　混合工程は、仮焼用の混合物を調製する工程である。混合工程では、まず、出発原料を秤量して所定の割合で配合し、湿式アトライタ、又はボールミル等で１～２０時間程度混合するとともに粉砕処理を行う。出発原料としては、鉄化合物の粉末、ストロンチウム化合物の粉末、並びに、構成元素としてリチウムを有するリチウム化合物の粉末が挙げられる。鉄化合物及びストロンチウム化合物としては、酸化物又は焼成により酸化物となる、炭酸塩、水酸化物又は硝酸塩等の化合物を用いることができる。このような化合物としては、例えば、ＳｒＣＯ３、Ｆｅ２Ｏ３等が挙げられる。また、これらの成分の他にＬａ（ＯＨ）３、及びＣｏ３Ｏ４などを添加してもよい。リチウム化合物としては、酸化物、炭酸塩、珪酸塩、リチウム含む有機化合物（分散剤）が挙げられる。 The mixing step is a step of preparing a mixture for calcination. In the mixing step, first, the starting materials are weighed and blended at a predetermined ratio, and mixed with a wet attritor or a ball mill for about 1 to 20 hours and pulverized. Examples of the starting material include iron compound powder, strontium compound powder, and lithium compound powder having lithium as a constituent element. As the iron compound and the strontium compound, an oxide or a compound such as carbonate, hydroxide, or nitrate that becomes an oxide by firing can be used. Examples of such compounds include SrCO 3 and Fe 2 O 3 . In addition to these components, La (OH) 3 and Co 3 O 4 may be added. Examples of the lithium compound include oxides, carbonates, silicates, and organic compounds (dispersants) containing lithium.
　リチウム化合物の混合量は、混合工程で得られる混合物におけるリチウムの含有量が、Ｌｉ２Ｏ換算で０．０１～０．５質量％、好ましくは０．０５～０．３質量％となるように混合する。 The mixing amount of the lithium compound is such that the lithium content in the mixture obtained in the mixing step is 0.01 to 0.5% by mass, preferably 0.05 to 0.3% by mass in terms of Li 2 O. Mix.
　混合工程では、上述のリチウム化合物に加えて、構成元素としてナトリウムを有するナトリウム化合物を添加することが好ましい。リチウム化合物とともにナトリウム化合物を添加することによって、フェライトの生成反応が促進されて、仮焼工程における仮焼温度を低くしても、短時間でＳｒフェライトを含む仮焼体を得ることができる。また、Ｓｒフェライトの含有率が一層高い仮焼体を得ることができる。 In the mixing step, it is preferable to add a sodium compound having sodium as a constituent element in addition to the above-described lithium compound. By adding a sodium compound together with the lithium compound, the ferrite formation reaction is promoted, and a calcined body containing Sr ferrite can be obtained in a short time even if the calcining temperature in the calcining step is lowered. In addition, a calcined body having a higher Sr ferrite content can be obtained.
　ナトリウム化合物の混合量は、混合工程で得られる混合物におけるナトリウムの含有量が、Ｎａ２Ｏ換算で好ましくは０．００５～０．８質量％、より好ましくは０．０１～０．６質量％となるように混合する。ナトリウム化合物の混合量をこのような範囲とすることによって、飽和磁化（σｓ）の高いＳｒフェライト粉末を一層短い仮焼時間で製造することができる。 The mixing amount of the sodium compound is such that the sodium content in the mixture obtained in the mixing step is preferably 0.005 to 0.8% by mass, more preferably 0.01 to 0.6% by mass in terms of Na 2 O. Mix to be. By setting the mixing amount of the sodium compound in such a range, Sr ferrite powder having a high saturation magnetization (σ s ) can be produced in a shorter calcining time.
　混合物におけるリチウム化合物及びナトリウム化合物の合計含有量は、リチウム化合物及びナトリウム化合物をそれぞれＬｉ２Ｏ及びＮａ２Ｏに換算して、好ましくは０．０１～１．０質量％、より好ましくは０．０２～０．５質量である。このよう範囲とすることによって、飽和磁化（σｓ）の高いＳｒフェライト粉末を一層短い仮焼時間で製造することができる。 The total content of the lithium compound and sodium compound in the mixture is preferably 0.01 to 1.0% by mass, more preferably 0.02 when the lithium compound and sodium compound are converted to Li 2 O and Na 2 O, respectively. Is 0.5 mass. By setting it as such a range, Sr ferrite powder with high saturation magnetization ((sigma) s ) can be manufactured in a shorter calcination time.
　リチウム化合物及びナトリウム化合物の他に、他の副成分を添加してもよい。そのような副成分としては、ＳｉＯ２及びＣａＣＯ３等が挙げられる。各出発原料の平均粒径は特に限定されず、例えば０．１～２．０μｍである。各出発原料のＢＥＴ法による比表面積は、２ｍ２／ｇ以上であることが好ましい。これによって、一層微細なＳｒフェライト粉末を得ることができる。混合工程で調製する混合物は、粉末状であってもよく、溶媒を含むスラリー中に分散されていてもよい。 Other subcomponents may be added in addition to the lithium compound and the sodium compound. Examples of such subcomponents include SiO 2 and CaCO 3 . The average particle diameter of each starting material is not particularly limited, and is, for example, 0.1 to 2.0 μm. The specific surface area of each starting material according to the BET method is preferably 2 m 2 / g or more. Thereby, a finer Sr ferrite powder can be obtained. The mixture prepared in the mixing step may be in the form of a powder or may be dispersed in a slurry containing a solvent.
　仮焼工程は、混合工程で得られた混合物を仮焼する工程である。仮焼は、空気中等の酸化性雰囲気中で行うことができる。仮焼工程における焼成温度（仮焼温度）は、８５０～１０５０℃である。高い飽和磁化を有するＳｒフェライト粉末を得る観点から、仮焼温度の下限は、好ましくは９００℃である。一方、十分に微細なＳｒフェライト粉末を得る観点から、仮焼温度の上限は、好ましくは１０００℃であり、より好ましくは９５０℃である。 The calcining step is a step of calcining the mixture obtained in the mixing step. Calcination can be performed in an oxidizing atmosphere such as air. The firing temperature (calcination temperature) in the calcination step is 850 to 1050 ° C. From the viewpoint of obtaining Sr ferrite powder having high saturation magnetization, the lower limit of the calcining temperature is preferably 900 ° C. On the other hand, from the viewpoint of obtaining sufficiently fine Sr ferrite powder, the upper limit of the calcining temperature is preferably 1000 ° C., more preferably 950 ° C.
　仮焼温度における仮焼時間は、好ましくは０．５～５時間、より好ましくは１～３時間である。仮焼して得られる仮焼体におけるＳｒフェライトの含有量は、好ましくは７０質量％以上であり、より好ましくは９０質量％以上である。本実施形態の製造方法では、仮焼工程で用いる混合物がリチウム化合物を含有することから、上述の仮焼温度でも六方晶構造を有するＳｒフェライトを十分に生成させることができる。 The calcination time at the calcination temperature is preferably 0.5 to 5 hours, more preferably 1 to 3 hours. The content of Sr ferrite in the calcined body obtained by calcining is preferably 70% by mass or more, and more preferably 90% by mass or more. In the manufacturing method of the present embodiment, since the mixture used in the calcining step contains a lithium compound, Sr ferrite having a hexagonal crystal structure can be sufficiently generated even at the calcining temperature described above.
　仮焼体の飽和磁化は、好ましくは６７ｅｍｕ／ｇ以上であり、より好ましくは７０ｅｍｕ／ｇ以上であり、さらに好ましくは７０．５ｅｍｕ／ｇ以上である。このように高い飽和磁化を有する仮焼体を生成させることによって、一層高い磁気特性を有するＳｒフェライト焼結磁石が得られる。本明細書における飽和磁化は、市販の振動試料型磁力計（ＶＳＭ）を用いて測定することができる。 The saturation magnetization of the calcined body is preferably 67 emu / g or more, more preferably 70 emu / g or more, and further preferably 70.5 emu / g or more. By producing a calcined body having high saturation magnetization in this way, a sintered Sr ferrite magnet having higher magnetic properties can be obtained. The saturation magnetization in this specification can be measured using a commercially available vibrating sample magnetometer (VSM).
　仮焼体のＢＥＴ法による比表面積は、最終的に得られるＳｒフェライト焼結磁石の組織を十分に微細にする観点から、好ましくは２ｍ２／ｇ以上であり、より好ましくは２．５ｍ２／ｇ以上である。また、仮焼体のＢＥＴ法による比表面積は、成形体を作製する際の成形性を良好にする観点から、好ましくは１５ｍ２／ｇ以下であり、より好ましくは１０ｍ２／ｇ以下であり、さらに好ましくは７ｍ２／ｇ以下である。なお、本明細書における比表面積は、市販のＢＥＴ比表面積測定装置（Ｍｏｕｎｔｅｃｈ製、商品名：ＨＭ　Ｍｏｄｅｌ－１２１０）を用いて測定することができる。 BET specific surface area of the calcined body, the finally obtained Sr ferrite sintered magnet tissue from the viewpoint of sufficiently fine, preferably 2m 2 / g or more, more preferably 2.5 m 2 / g or more. Further, the specific surface area of the calcined body by the BET method is preferably 15 m 2 / g or less, more preferably 10 m 2 / g or less, from the viewpoint of improving the moldability when producing a molded body. More preferably, it is 7 m 2 / g or less. In addition, the specific surface area in this specification can be measured using a commercially available BET specific surface area measuring apparatus (manufactured by Mountaintech, trade name: HM Model-1210).
　粉砕工程では、混合工程で得られた混合物を仮焼して得られる仮焼体の粉砕を行い、粉砕粉を調製する。粉砕は、一段階で行ってもよく、粗粉砕工程と微粉砕工程の二段階に分けて行ってもよい。仮焼体は、通常顆粒状又は塊状であるため、まずは粗粉砕工程を行うことが好ましい。粗粉砕工程では、振動ロッドミル等を使用して乾式で粉砕を行って、粗粉砕粉を調製する。このようにして調製した粗粉砕粉を、湿式アトライタ、ボールミル、又はジェットミル等を用いて湿式で粉砕して微粉砕粉を得る。粉砕時間は、例えば湿式アトライタを用いる場合、３０分間～１０時間であり、ボールミルを用いる場合、５～５０時間である。これらの時間は、粉砕方法によって適宜調整することが好ましい。本実施形態の製造方法では、従来よりも低い温度で仮焼を行っているため、仮焼体におけるＳｒフェライトの一次粒子は従来よりも微細である。したがって、粉砕工程（特に微粉砕工程）は、微細な一次粒子が分散される意味合いが強くなる。 In the pulverization step, the calcined body obtained by calcination of the mixture obtained in the mixing step is pulverized to prepare pulverized powder. The pulverization may be performed in one stage, or may be performed in two stages, a coarse pulverization process and a fine pulverization process. Since the calcined body is usually granular or massive, it is preferable to first perform a coarse pulverization step. In the coarse pulverization step, a coarse pulverized powder is prepared by performing dry pulverization using a vibrating rod mill or the like. The coarsely pulverized powder thus prepared is wet pulverized using a wet attritor, ball mill, jet mill or the like to obtain a finely pulverized powder. The pulverization time is, for example, 30 minutes to 10 hours when using a wet attritor, and 5 to 50 hours when using a ball mill. These times are preferably adjusted appropriately depending on the pulverization method. In the manufacturing method of the present embodiment, calcination is performed at a temperature lower than that in the prior art, so the primary particles of Sr ferrite in the calcined body are finer than in the past. Therefore, the pulverization process (particularly the pulverization process) has a strong meaning of dispersing fine primary particles.
　粉砕工程では、副成分であるＳｉＯ２，ＣａＣＯ３，ＳｒＣＯ３及びＢａＣＯ３等の粉末を添加してもよい。このような副成分を添加することによって、焼結性を向上すること、及び磁気特性を向上することができる。なお、これらの副成分は、湿式で成形を行う場合にスラリーの溶媒とともに流出することがあるため、Ｓｒフェライト焼結磁石における目標の含有量よりも多めに配合することが好ましい。 In the pulverization step, powders such as SiO 2 , CaCO 3 , SrCO 3, and BaCO 3 that are subcomponents may be added. By adding such a subcomponent, sinterability can be improved and magnetic properties can be improved. In addition, since these subcomponents may flow out together with the solvent of the slurry when forming in a wet manner, it is preferable to add more than the target content in the sintered Sr ferrite magnet.
　Ｓｒフェライト焼結磁石の磁気的配向度を高めるために、上述の副成分に加えて、多価アルコールを微粉砕工程で添加することが好ましい。多価アルコールの添加量は、添加対象物に対して０．０５～５．０質量％、好ましくは０．１～３．０質量％、より好ましくは０．３～２．０質量％である。なお、添加した多価アルコールは、焼結工程で熱分解して除去される。 In order to increase the degree of magnetic orientation of the sintered Sr ferrite magnet, it is preferable to add polyhydric alcohol in the pulverization step in addition to the above-mentioned subcomponents. The addition amount of the polyhydric alcohol is 0.05 to 5.0% by mass, preferably 0.1 to 3.0% by mass, more preferably 0.3 to 2.0% by mass with respect to the addition target. . The added polyhydric alcohol is thermally decomposed and removed in the sintering process.
　粉砕工程で得られる粉砕粉のＢＥＴ法による比表面積は、最終的に得られるＳｒフェライト焼結磁石の組織を十分に微細にする観点から、好ましくは６ｍ２／ｇ以上であり、より好ましくは８ｍ２／ｇ以上である。また、粉砕粉のＢＥＴ法による比表面積は、成形体を作製する際の成形性を良好にする観点から、好ましくは１２ｍ２／ｇ以下であり、より好ましくは１０ｍ２／ｇ以下である。このような比表面積を有する粉砕粉は、十分に微細で、且つ取扱い性及び成形性に優れることから、工程の簡便性を維持しつつ、Ｓｒフェライト焼結磁石の組織を一層微細化して、Ｓｒフェライト焼結磁石の磁気特性を一層向上することができる。 The specific surface area by the BET method of the pulverized powder obtained in the pulverization step is preferably 6 m 2 / g or more, more preferably 8 m, from the viewpoint of sufficiently finening the structure of the finally obtained Sr ferrite sintered magnet. 2 / g or more. In addition, the specific surface area of the pulverized powder by the BET method is preferably 12 m 2 / g or less, more preferably 10 m 2 / g or less, from the viewpoint of improving the moldability when producing a molded body. Since the pulverized powder having such a specific surface area is sufficiently fine and excellent in handleability and formability, the structure of the sintered Sr ferrite magnet is further refined while maintaining the simplicity of the process, and the Sr The magnetic properties of the sintered ferrite magnet can be further improved.
　以上の工程によって、Ｓｒフェライト粉末を得ることができる。このようして得られるＳｒフェライト粉末は、リチウムを含有する混合物を用いて焼成されたものであることから、十分に微細であるうえに粒子の均一性が高く、且つ高いσｓを有する。Ｓｒフェライト粉末における六方晶構造を有するＳｒフェライトの含有量は、好ましくは５０質量％以上であり、より好ましくは７０質量％以上であり、さらに好ましくは８０質量％以上である。 Sr ferrite powder can be obtained through the above steps. Since the Sr ferrite powder thus obtained is fired using a mixture containing lithium, it is sufficiently fine, has high particle uniformity, and has a high σ s . The content of Sr ferrite having a hexagonal crystal structure in the Sr ferrite powder is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more.
　Ｓｒフェライト粉末は、Ｓｒフェライト以外の成分として、鉄化合物及びストロンチウム化合物などの未反応の原料、リチウム化合物、ナトリウム化合物、並びにその他の成分を含有していてもよい。その他の成分としては、Ｋ（カリウム）、Ｓｉ（ケイ素），Ｃａ（カルシウム），Ｓｒ（ストロンチウム）及びＢａ（バリウム）から選ばれる少なくとも一種を有する酸化物並びに複合酸化物が挙げられる。酸化物としては、例えばＫ２Ｏ，ＳｉＯ２、ＣａＯ、ＳｒＯ、及びＢａＯが挙げられる。 The Sr ferrite powder may contain unreacted raw materials such as an iron compound and a strontium compound, a lithium compound, a sodium compound, and other components as components other than the Sr ferrite. Other components include oxides and composite oxides having at least one selected from K (potassium), Si (silicon), Ca (calcium), Sr (strontium) and Ba (barium). Examples of the oxide include K 2 O, SiO 2 , CaO, SrO, and BaO.
　Ｓｒフェライト粉末の飽和磁化は、好ましくは６７ｅｍｕ／ｇ以上であり、より好ましくは７０ｅｍｕ／ｇ以上であり、さらに好ましくは７０．５ｅｍｕ／ｇ以上である。このように高い飽和磁化を有する仮焼体を生成させることによって、一層高い磁気特性を有するＳｒフェライト焼結磁石が得られる。 The saturation magnetization of the Sr ferrite powder is preferably 67 emu / g or more, more preferably 70 emu / g or more, and further preferably 70.5 emu / g or more. By producing a calcined body having high saturation magnetization in this way, a sintered Sr ferrite magnet having higher magnetic properties can be obtained.
　次に、本発明のＳｒフェライト焼結磁石の製造方法の好適な実施形態を説明する。本実施形態のＳｒフェライト焼結磁石の製造方法は、鉄化合物の粉末、ストロンチウム化合物の粉末、並びに、構成元素としてリチウムを有する化合物の粉末を混合して混合物を調製する混合工程と、該混合物を８５０～１０５０℃で焼成して、六方晶構造を有するＳｒフェライトを含む仮焼体を得る仮焼工程と、仮焼体を粉砕してＳｒフェライト粉末を得る粉砕工程と、Ｓｒフェライト粉末を磁場中成形して成形体を得る成形工程と、成形体を１０００～１２５０℃で焼成してＳｒフェライト焼結磁石を得る焼結工程と、を有する。混合工程、仮焼工程及び粉砕工程は、上述のＳｒフェライト粉末の製造方法と同様である。ここでは、重複する説明は行わず、成形工程及び焼結工程について説明する。 Next, a preferred embodiment of the method for producing a sintered Sr ferrite magnet of the present invention will be described. The method for producing a sintered Sr ferrite magnet of this embodiment includes a mixing step of preparing a mixture by mixing an iron compound powder, a strontium compound powder, and a compound powder having lithium as a constituent element; Calcining at 850 to 1050 ° C. to obtain a calcined body containing Sr ferrite having a hexagonal crystal structure, crushing process to crush the calcined body to obtain Sr ferrite powder, and Sr ferrite powder in a magnetic field A molding step of molding to obtain a molded body, and a sintering step of firing the molded body at 1000 to 1250 ° C. to obtain a Sr ferrite sintered magnet. The mixing step, calcination step, and pulverization step are the same as the above-described method for producing Sr ferrite powder. Here, the overlapping process will not be described, and the forming process and the sintering process will be described.
　成形工程では、まず、粉砕工程で得られた粉砕粉を磁場中で成形して成形体を作製する磁場中成形を行う。磁場中成形は、乾式成形、又は湿式成形のどちらの方法でも行ってもよく、磁気的配向度を高くする観点から、好ましくは湿式成形である。湿式成形を行う場合、粉砕粉と分散媒とを配合して粉砕する湿式粉砕を行ってスラリーを調製し、これを用いて成形体を作製することもできる。スラリーの濃縮は、遠心分離やフィルタープレス等によって行うことができる。 In the molding process, first, the pulverized powder obtained in the pulverization process is molded in a magnetic field to form a molded body. The molding in the magnetic field may be performed by either dry molding or wet molding, and is preferably wet molding from the viewpoint of increasing the degree of magnetic orientation. In the case of performing wet molding, a slurry can be prepared by blending a pulverized powder and a dispersion medium and pulverizing to prepare a slurry, and a molded product can be produced using the slurry. Concentration of the slurry can be performed by centrifugation, filter press, or the like.
　スラリー中における固形分の含有量は、好ましくは３０～８５質量％である。スラリーの分散媒としては水又は非水系溶媒を用いることができる。スラリーには、水に加えて、グルコン酸、グルコン酸塩、又はソルビトール等の界面活性剤を添加してもよい。このようなスラリーを用いて磁場中成形を行って、成形体を作製する。成形圧力は例えば０．１～０．５トン／ｃｍ２であり、印加磁場は例えば５～１５ｋＯｅである。 The solid content in the slurry is preferably 30 to 85% by mass. As the dispersion medium of the slurry, water or a non-aqueous solvent can be used. In addition to water, a surfactant such as gluconic acid, gluconate, or sorbitol may be added to the slurry. Using such a slurry, molding is performed in a magnetic field to produce a molded body. The molding pressure is, for example, 0.1 to 0.5 ton / cm 2 , and the applied magnetic field is, for example, 5 to 15 kOe.
　続いて、焼成工程において、成形体を焼成して焼結体を作製する。焼成は、通常、大気中等の酸化性雰囲気中で行う。焼成温度は、１０００～１２５０℃であり、好ましくは１１００～１２００℃である。焼成温度における焼成時間は、好ましくは０．５～３時間である。以上の工程によって、焼結体、すなわちＳｒフェライト焼結磁石を得ることができる。 Subsequently, in the firing step, the compact is fired to produce a sintered body. Firing is usually performed in an oxidizing atmosphere such as air. The firing temperature is 1000 to 1250 ° C., preferably 1100 to 1200 ° C. The firing time at the firing temperature is preferably 0.5 to 3 hours. Through the above steps, a sintered body, that is, a Sr ferrite sintered magnet can be obtained.
　本実施形態のＳｒフェライト焼結磁石の製造方法では、比表面積の大きい微細な仮焼体を用いていることから、組織が微細で組織の均一性の高いＳｒフェライト焼結磁石を得ることができる。このようなＳｒフェライト焼結磁石は、高いＢｒを有するため、モータ用又は発電機用の磁石として好適に用いられる。 In the method for producing a sintered Sr ferrite magnet of the present embodiment, since a fine calcined body having a large specific surface area is used, it is possible to obtain an Sr ferrite sintered magnet having a fine structure and high structure uniformity. . Since such Sr ferrite sintered magnet has high Br, it is suitably used as a magnet for a motor or a generator.
　図１は、本実施形態の製造方法で得られるＳｒフェライト焼結磁石を模式的に示す斜視図である。異方性のＳｒフェライト焼結磁石１０は、端面が円弧状となるように湾曲した形状を有しており、一般にアークセグメント形状、Ｃ形形状、瓦型形状、又は弓形形状と呼ばれる形状を有している。Ｓｒフェライト焼結磁石１０は、例えばモータ用又は発電機用の磁石として好適に用いられる。 FIG. 1 is a perspective view schematically showing a Sr ferrite sintered magnet obtained by the manufacturing method of the present embodiment. The anisotropic Sr ferrite sintered magnet 10 has a curved shape so that the end surface is arcuate, and generally has a shape called an arc segment shape, a C shape, a tile shape, or an arc shape. is doing. The Sr ferrite sintered magnet 10 is suitably used as a magnet for a motor or a generator, for example.
　Ｓｒフェライト焼結磁石１０は、主成分として、六方晶構造を有するＭ型のＳｒフェライトの結晶粒を含有する。Ｓｒフェライトは、例えば以下の式（１）で表わされる。
　　ＳｒＦｅ１２Ｏ１９　　　　　　（１） Sr ferrite sintered magnet 10 contains crystal grains of M-type Sr ferrite having a hexagonal crystal structure as a main component. Sr ferrite is represented by the following formula (1), for example.
SrFe 12 O 19 (1)
　上式（１）のＳｒフェライトにおけるＡサイトのＳｒ及びＢサイトのＦｅは、不純物又は意図的に添加された元素によって、その一部が置換されていてもよい。また、ＡサイトとＢサイトの比率が若干ずれていてもよい。この場合、Ｓｒフェライトは、例えば以下の一般式（２）で表わすことができる。
　　ＲｘＳｒ１－ｘ（Ｆｅ１２－ｙＭｙ）ｚＯ１９　　　　（２）
　上式（２）中、ｘ及びｙは、例えば０．１～０．５であり、ｚは０．７～１．２である。 In the Sr ferrite of the above formula (1), Sr at the A site and Fe at the B site may be partially substituted by impurities or intentionally added elements. Further, the ratio between the A site and the B site may be slightly shifted. In this case, the Sr ferrite can be expressed by, for example, the following general formula (2).
R x Sr 1-x (Fe 12-y M y ) z O 19 (2)
In the above formula (2), x and y are, for example, 0.1 to 0.5, and z is 0.7 to 1.2.
　一般式（２）におけるＭは、例えば、Ｃｏ（コバルト）、Ｚｎ（亜鉛）、Ｎｉ（ニッケル）、Ｍｎ（マンガン）、Ａｌ（アルミニウム）及びＣｒ（クロム）からなる群より選ばれる１種以上の元素である。また、一般式（３）におけるＲは、例えば、Ｌａ（ランタン）、Ｃｅ（セリウム）、Ｐｒ（プラセオジム）、Ｎｄ（ネオジム）及びＳｍ（サマリウム）からなる群より選ばれる１種以上の元素である。 M in the general formula (2) is, for example, one or more selected from the group consisting of Co (cobalt), Zn (zinc), Ni (nickel), Mn (manganese), Al (aluminum), and Cr (chromium). It is an element. R in the general formula (3) is, for example, one or more elements selected from the group consisting of La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), and Sm (samarium). .
　Ｓｒフェライト焼結磁石１０におけるＳｒフェライト相の比率は、好ましくは９５％以上であり、より好ましくは９７％以上であり、さらに好ましくは９９％以上である。このように、Ｓｒフェライト相とは異なる結晶相の比率を低減することによって、磁気特性を一層高くすることができる。Ｓｒフェライト焼結磁石１０におけるＳｒフェライト相の比率（％）は、Ｓｒフェライトの飽和磁化の理論値をσｔ、実測値をσｓとしたとき、（σｓ／σｔ）×１００の計算式で求めることができる。 The ratio of the Sr ferrite phase in the sintered Sr ferrite magnet 10 is preferably 95% or more, more preferably 97% or more, and further preferably 99% or more. Thus, by reducing the ratio of the crystal phase different from the Sr ferrite phase, the magnetic properties can be further enhanced. The ratio of Sr ferrite phase in Sr ferrite sintered magnet 10 (%) is the theoretical value of the saturation magnetization of the Sr ferrite sigma t, when the actually measured values σ s, (σ s / σ t) × 100 formula Can be obtained.
　Ｓｒフェライト焼結磁石１０は、副成分として、Ｓｒフェライトとは異なる成分を含有する。副成分としては、構成元素として、Ｌｉ（リチウム）及び／又はＮａ（ナトリウム）を有するアルカリ金属化合物が挙げられる。アルカリ金属化合物としては、例えばＬｉ２Ｏ及びＮａ２Ｏなどの酸化物やケイ酸ガラスが挙げられる。Ｓｒフェライト焼結磁石１０におけるＬｉの含有量は、Ｌｉ２Ｏに換算して０．０１～０．５質量％であり、好ましくは０．０１～０．３質量％である。 The Sr ferrite sintered magnet 10 contains a component different from Sr ferrite as a subcomponent. Examples of the subcomponent include alkali metal compounds having Li (lithium) and / or Na (sodium) as constituent elements. Examples of the alkali metal compound include oxides such as Li 2 O and Na 2 O and silicate glass. The Li content in the sintered Sr ferrite magnet 10 is 0.01 to 0.5% by mass, preferably 0.01 to 0.3% by mass in terms of Li 2 O.
　Ｓｒフェライト焼結磁石１０におけるＮａの含有量は、Ｎａ２Ｏに換算して０．０１～０．２質量％である。Ｓｒフェライト焼結磁石１０におけるＬｉ及びＮａの合計含有量は、Ｌｉ及びＮａをそれぞれＬｉ２Ｏ及びＮａ２Ｏに換算して、０．０２～０．５質量％である。Ｓｒフェライト焼結磁石１０におけるＬｉ及び／又はＮａの含有量が過剰になると、表面に白粉が発生しやすくなる傾向にある。一方、Ｓｒフェライト焼結磁石１０におけるＬｉ及び／又はＮａの含有量が過少になると、焼結に要する時間が長くなる傾向にある。 The content of Na in the sintered Sr ferrite magnet 10 is 0.01 to 0.2% by mass in terms of Na 2 O. The total content of Li and Na in the Sr ferrite sintered magnet 10 is 0.02 to 0.5 mass% when Li and Na are converted to Li 2 O and Na 2 O, respectively. When the content of Li and / or Na in the Sr ferrite sintered magnet 10 becomes excessive, white powder tends to be generated on the surface. On the other hand, when the content of Li and / or Na in the Sr ferrite sintered magnet 10 becomes too small, the time required for sintering tends to become longer.
　Ｓｒフェライト焼結磁石１０は、副成分として、上述のアルカリ金属化合物の他に、任意の成分を含有していてもよい。そのような成分としては、Ｋ（カリウム）、Ｓｉ（ケイ素），Ｃａ（カルシウム），Ｓｒ（ストロンチウム）及びＢａ（バリウム）から選ばれる少なくとも一種を有する酸化物並びに複合酸化物が挙げられる。酸化物としては、例えばＫ２Ｏ，ＳｉＯ２、ＣａＯ、ＳｒＯ、及びＢａＯが挙げられる。 The Sr ferrite sintered magnet 10 may contain an arbitrary component in addition to the above-described alkali metal compound as a subcomponent. Examples of such components include oxides and composite oxides having at least one selected from K (potassium), Si (silicon), Ca (calcium), Sr (strontium), and Ba (barium). Examples of the oxide include K 2 O, SiO 2 , CaO, SrO, and BaO.
　Ｓｒフェライト焼結磁石１０におけるＳｉの含有量は、例えば、ＳｉＯ２換算で０．１～１．０質量％である。Ｓｒフェライト焼結磁石１０におけるＳｒの含有量は、例えば、ＳｒＯ換算で１０～１３質量％である。Ｓｒフェライト焼結磁石１０は、Ｂａを含有していてもよい。Ｓｒフェライト焼結磁石１０におけるＢａの含有量は、例えば、ＢａＯ換算で０．０１～２．０質量％である。Ｓｒフェライト焼結磁石１０におけるＣａの含有量は、例えば、ＣａＯ換算で０．０５～２質量％である。Ｓｒフェライト焼結磁石１０には、これらの成分の他に、原料に含まれる不純物や製造設備に由来する不可避的な成分が含まれていてもよい。このような成分としては、例えば、Ｔｉ（チタン），Ｃｒ（クロム），Ｍｎ（マンガン），Ｍｏ（モリブデン），Ｖ（バナジウム）及びＡｌ（アルミニウム）等の各酸化物が挙げられる。 The Si content in the sintered Sr ferrite magnet 10 is, for example, 0.1 to 1.0 mass% in terms of SiO 2 . The Sr content in the sintered Sr ferrite magnet 10 is, for example, 10 to 13% by mass in terms of SrO. The Sr ferrite sintered magnet 10 may contain Ba. The Ba content in the sintered Sr ferrite magnet 10 is, for example, 0.01 to 2.0 mass% in terms of BaO. The Ca content in the sintered Sr ferrite magnet 10 is, for example, 0.05 to 2% by mass in terms of CaO. In addition to these components, the Sr ferrite sintered magnet 10 may contain impurities contained in the raw materials and inevitable components derived from the manufacturing equipment. Examples of such components include Ti (titanium), Cr (chromium), Mn (manganese), Mo (molybdenum), V (vanadium), and Al (aluminum) oxides.
　副成分は、主に、Ｓｒフェライト焼結磁石１０におけるＳｒフェライトの結晶粒の粒界に含まれる。Ｓｒフェライト焼結磁石１０の各成分の含有量は、蛍光Ｘ線分析及び誘導結合プラズマ発光分光分析（ＩＣＰ分析）によって測定することができる。 The subcomponents are mainly contained in the grain boundaries of the Sr ferrite crystal grains in the Sr ferrite sintered magnet 10. The content of each component of the sintered Sr ferrite magnet 10 can be measured by fluorescent X-ray analysis and inductively coupled plasma emission spectroscopic analysis (ICP analysis).
　Ｓｒフェライト焼結磁石１０は、例えば、フューエルポンプ用、パワーウィンドウ用、ＡＢＳ（アンチロック・ブレーキ・システム）用、ファン用、ワイパ用、パワーステアリング用、アクティブサスペンション用、スタータ用、ドアロック用、電動ミラー用等の自動車用モータの磁石として使用することができる。また、ＦＤＤスピンドル用、ＶＴＲキャプスタン用、ＶＴＲ回転ヘッド用、ＶＴＲリール用、ＶＴＲローディング用、ＶＴＲカメラキャプスタン用、ＶＴＲカメラ回転ヘッド用、ＶＴＲカメラズーム用、ＶＴＲカメラフォーカス用、ラジカセ等キャプスタン用、ＣＤ／ＤＶＤ／ＭＤスピンドル用、ＣＤ／ＤＶＤ／ＭＤローディング用、ＣＤ／ＤＶＤ光ピックアップ用等のＯＡ／ＡＶ機器用モータの磁石として使用することができる。さらに、エアコンコンプレッサー用、冷凍庫コンプレッサー用、電動工具駆動用、ドライヤーファン用、シェーバー駆動用、電動歯ブラシ用等の家電機器用モータの磁石としても使用することができる。さらにまた、ロボット軸、関節駆動用、ロボット主駆動用、工作機器テーブル駆動用、工作機器ベルト駆動用等のＦＡ機器用モータの磁石としても使用することが可能である。 Sr ferrite sintered magnet 10 is, for example, for fuel pump, power window, ABS (anti-lock brake system), fan, wiper, power steering, active suspension, starter, door lock, It can be used as a magnet for an automobile motor such as an electric mirror. Also for FDD spindle, VTR capstan, VTR rotary head, VTR reel, VTR loading, VTR camera capstan, VTR camera rotary head, VTR camera zoom, VTR camera focus, radio cassette etc. It can be used as a magnet for motors for OA / AV devices such as CD / DVD / MD spindle, CD / DVD / MD loading, and CD / DVD optical pickup. Furthermore, it can also be used as a magnet for a motor for home appliances such as an air conditioner compressor, a freezer compressor, an electric tool drive, a dryer fan, a shaver drive, an electric toothbrush and the like. Furthermore, it can also be used as a magnet for a motor for FA equipment such as a robot shaft, joint drive, robot main drive, machine tool table drive, machine tool belt drive and the like.
　Ｓｒフェライト焼結磁石１０は、上述のモータの部材に接着してモータ内に設置される。Ｓｒフェライト焼結磁石１０は高いＢｒを有することから、Ｓｒフェライト焼結磁石１０を備える各種モータは、高い効率を有する。 The Sr ferrite sintered magnet 10 is attached to the above-mentioned motor member and installed in the motor. Since the Sr ferrite sintered magnet 10 has high Br, various motors including the Sr ferrite sintered magnet 10 have high efficiency.
　図３は、Ｓｒフェライト焼結磁石１０を備えるモータ３０の実施形態を模式的に示す断面図である。本実施形態のモータ３０は、ブラシ付き直流モータであり、有底筒状のハウジング３１（ステータ）と、ハウジング３１の内周側に同心に配置された回転可能なロータ３２と、を備える。ロータ３２は、ロータ軸３６とロータ軸３６上に固定されたロータコア３７とを備える。 FIG. 3 is a cross-sectional view schematically showing an embodiment of the motor 30 including the Sr ferrite sintered magnet 10. The motor 30 of the present embodiment is a DC motor with a brush, and includes a bottomed cylindrical housing 31 (stator) and a rotatable rotor 32 disposed concentrically on the inner peripheral side of the housing 31. The rotor 32 includes a rotor shaft 36 and a rotor core 37 fixed on the rotor shaft 36.
　ハウジング３１の開口部にはブラケット３３が嵌め込まれており、ロータコアは、ハウジング３１とブラケット３３とで形成される空間内に収容されている。ロータ軸３６は、互いに対向するように、ハウジング３１の中心部とブラケット３３の中心部にそれぞれ設けられた軸受３４，３５によって回転可能に支持されている。ハウジング３１の筒部分の内周面には、２個のＣ型のＳｒフェライト焼結磁石１０が互いに対向するように固定されている。 A bracket 33 is fitted in the opening of the housing 31, and the rotor core is accommodated in a space formed by the housing 31 and the bracket 33. The rotor shaft 36 is rotatably supported by bearings 34 and 35 provided at the center portion of the housing 31 and the center portion of the bracket 33 so as to face each other. Two C-type Sr ferrite sintered magnets 10 are fixed to the inner peripheral surface of the cylindrical portion of the housing 31 so as to face each other.
　図４は、図３のモータ３０のＩＶ－ＩＶ線断面図である。モータ用磁石であるＳｒフェライト焼結磁石１０は、その外周面を接着面として、ハウジング３１の内周面上に接着剤で接着されている。Ｓｒフェライト焼結磁石１０は、表面において粉体等の異物の析出が十分に抑制されていることから、ハウジング３１とＳｒフェライト焼結磁石１０との接着性は良好である。したがって、モータ３０は優れた特性とともに優れた信頼性を有する。 FIG. 4 is a cross-sectional view taken along line IV-IV of the motor 30 in FIG. The Sr ferrite sintered magnet 10 that is a motor magnet is bonded to the inner peripheral surface of the housing 31 with an adhesive, with the outer peripheral surface serving as an adhesive surface. Since the Sr ferrite sintered magnet 10 has sufficiently suppressed the precipitation of foreign substances such as powder on the surface, the adhesion between the housing 31 and the Sr ferrite sintered magnet 10 is good. Therefore, the motor 30 has excellent reliability as well as excellent characteristics.
　Ｓｒフェライト焼結磁石１０の用途は、モータ及び発電機に限定されるものではなく、例えば、スピーカ・ヘッドホン用マグネット、マグネトロン管、ＭＲＩ用磁場発生装置、ＣＤ－ＲＯＭ用クランパ、ディストリビュータ用センサ、ＡＢＳ用センサ、燃料・オイルレベルセンサ、マグネトラッチ、又はアイソレータ等の部材として用いることもできる。また、磁気記録媒体の磁性層を蒸着法又はスパッタ法等で形成する際のターゲット（ペレット）として用いることもできる。 Applications of the sintered Sr ferrite magnet 10 are not limited to motors and generators. For example, magnets for speakers and headphones, magnetron tubes, magnetic field generators for MRI, CD-ROM clampers, distributor sensors, ABS It can also be used as a member such as an engine sensor, a fuel / oil level sensor, a magnet latch, or an isolator. It can also be used as a target (pellet) when forming the magnetic layer of the magnetic recording medium by vapor deposition or sputtering.
　以上、本発明の好適な実施形態を説明したが、本発明は上述の実施形態に限定されるものではない。例えば、Ｓｒフェライト焼結磁石の形状は、図１の形状に限定されず、上述の各用途に適した形状に適宜変更することができる。また、上述の実施形態では、仮焼体を粉砕してＳｒフェライト粉末を得ているが、本発明の製造方法によって得られるＳｒフェライト粉末は、粉砕していない仮焼体であってもよい。 The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments. For example, the shape of the Sr ferrite sintered magnet is not limited to the shape shown in FIG. 1 and can be appropriately changed to a shape suitable for each application described above. In the above-described embodiment, the calcined body is pulverized to obtain Sr ferrite powder. However, the Sr ferrite powder obtained by the production method of the present invention may be a calcined body that has not been pulverized.
　本発明の内容を実施例及び比較例を参照してさらに詳細に説明するが、本発明は以下の実施例に限定されるものではない。 The contents of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.
［Ｓｒフェライト粉末の作製１］
（実施例１－１～１－５、比較例１－１～１－２）
　以下の出発原料を準備した。なお、比表面積はＢＥＴ法によって測定された値である。
・Ｆｅ２Ｏ３粉末（比表面積：４．４ｍ２／ｇ）２２０ｇ
・ＳｒＣＯ３粉末（比表面積：５．０ｍ２／ｇ）３５．２３ｇ [Preparation of Sr ferrite powder 1]
(Examples 1-1 to 1-5, Comparative Examples 1-1 to 1-2)
The following starting materials were prepared: The specific surface area is a value measured by the BET method.
・ Fe 2 O 3 powder (specific surface area: 4.4 m 2 / g) 220 g
・ SrCO 3 powder (specific surface area: 5.0 m 2 / g) 35.23 g
　上述のＦｅ２Ｏ３粉末及びＳｒＣＯ３粉末を、湿式ボールミルを用いて１６時間粉砕しながら混合してスラリーを得た。このスラリーに、炭酸リチウム粉末を添加した。このときの添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対して、Ｌｉ２Ｏ換算で０．１９質量％とした。その後、スラリーのスプレー乾燥を行って粒径が約１０μmの顆粒状の混合物を得た。当該混合物を大気中、表１に示す仮焼温度Ｔ１（８００～１１００℃）で１時間焼成して、六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。 The above-mentioned Fe 2 O 3 powder and SrCO 3 powder were mixed while being pulverized for 16 hours using a wet ball mill to obtain a slurry. To this slurry was added lithium carbonate powder. The addition amount at this time was set to 0.19% by mass in terms of Li 2 O with respect to the total mass of the Fe 2 O 3 powder and the SrCO 3 powder. Thereafter, the slurry was spray-dried to obtain a granular mixture having a particle size of about 10 μm. The mixture was fired in the air at a calcining temperature T 1 (800 to 1100 ° C.) shown in Table 1 for 1 hour to obtain a granular calcined body containing Sr ferrite having a hexagonal crystal structure.
　得られた仮焼体の磁気特性（飽和磁化及び保磁力）を、市販の振動試料型磁力計（ＶＳＭ）を用いて測定した。測定方法は次のとおりとした。ＶＳＭ（東英工業株式会社製、商品名：ＶＳＭ－３型）によって、１６ｋＯｅから１９ｋＯｅの磁場（Ｈｅｘ）における磁化（σ）を測定した。そして、飽和漸近則によってＨｅｘが無限大におけるσの値（σｓ）を計算した。すなわち、σを１／Ｈｅｘ２に対してプロットして直線近似し、１／Ｈｅｘ２→０に外挿したときの値を求めた。この時の相関係数は９９％以上であった。また、得られた仮焼体のＢＥＴ法による比表面積を測定した。これらの測定結果を表１に纏めて示す。 The magnetic properties (saturation magnetization and coercive force) of the obtained calcined body were measured using a commercially available vibrating sample magnetometer (VSM). The measurement method was as follows. Magnetization (σ) in a magnetic field (Hex) of 16 kOe to 19 kOe was measured by VSM (manufactured by Toei Kogyo Co., Ltd., trade name: VSM-3 type). Then, the value of σ (σ s ) when Hex is infinite was calculated by the saturation asymptotic rule. That is, σ was plotted against 1 / Hex 2 and linear approximation was performed, and a value obtained by extrapolating 1 / Hex 2 → 0 was obtained. The correlation coefficient at this time was 99% or more. Moreover, the specific surface area by BET method of the obtained calcined body was measured. These measurement results are summarized in Table 1.
　得られた仮焼体におけるＬｉのＬｉ２Ｏ換算の含有量を、市販のＩＣＰ分析装置を用いて測定した。その結果、実施例１－１～１－５及び比較例１－１～１－２におけるＬｉ２Ｏ換算のＬｉ含有量は０．１９質量％であった。 The Li 2 O equivalent content of Li in the obtained calcined body was measured using a commercially available ICP analyzer. As a result, the Li content in terms of Li 2 O in Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-2 was 0.19% by mass.
（比較例１－３～１－９）
　炭酸リチウム粉末の代わりに炭酸カリウム粉末を用いたこと以外は、実施例１－１～１－５と同様にして顆粒状の混合物を得た。炭酸カリウム粉末の添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対して、Ｋ２Ｏ換算で０．４６質量％とした。当該混合物を大気中、表２に示す仮焼温度Ｔ１（８００～１１００℃）で１時間焼成して、顆粒状の仮焼体を得た。得られた仮焼体の磁気特性を実施例１－１～１－５と同様にして測定した。測定結果を纏めて表２に示す。 (Comparative Examples 1-3 to 1-9)
A granular mixture was obtained in the same manner as in Examples 1-1 to 1-5 except that potassium carbonate powder was used instead of lithium carbonate powder. The addition amount of the potassium carbonate powder was 0.46% by mass in terms of K 2 O with respect to the total mass of the Fe 2 O 3 powder and the SrCO 3 powder. The mixture was calcined in the air at a calcining temperature T 1 (800 to 1100 ° C.) shown in Table 2 for 1 hour to obtain a granular calcined body. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 1-1 to 1-5. The measurement results are summarized in Table 2.
（比較例１－１０～１－１６）
　炭酸リチウム粉末の代わりにケイ酸カリウム粉末を用いたこと以外は、実施例１－１～１－５と同様にして顆粒状の混合物を得た。ケイ酸カリウム粉末の添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対して、Ｋ２Ｏ換算で０．４６質量％とした。当該混合物を大気中、表３に示す仮焼温度Ｔ１（８００～１１００℃）で１時間焼成して、顆粒状の仮焼体を得た。得られた仮焼体の磁気特性を実施例１－１～１－５と同様にして測定した。測定結果を纏めて表３に示す。 (Comparative Examples 1-10 to 1-16)
A granular mixture was obtained in the same manner as in Examples 1-1 to 1-5, except that potassium silicate powder was used instead of lithium carbonate powder. The addition amount of the potassium silicate powder was 0.46% by mass in terms of K 2 O with respect to the total mass of the Fe 2 O 3 powder and the SrCO 3 powder. The mixture was calcined in the air at a calcining temperature T 1 (800 to 1100 ° C.) shown in Table 3 for 1 hour to obtain a granular calcined body. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 1-1 to 1-5. The measurement results are summarized in Table 3.
（比較例１－１７～１－２３）
　炭酸リチウム粉末を添加しなかったこと以外は、実施例１－１～１－５と同様にして顆粒状の混合物を得た。当該混合物を大気中、表４に示す仮焼温度Ｔ１（８００～１１００℃）で１時間焼成して、顆粒状の仮焼体を得た。得られた仮焼体の磁気特性を実施例１－１～１－５と同様にして測定した。測定結果を纏めて表４に示す。 (Comparative Examples 1-17 to 1-23)
A granular mixture was obtained in the same manner as in Examples 1-1 to 1-5 except that the lithium carbonate powder was not added. The mixture was fired in the air at a calcining temperature T 1 (800 to 1100 ° C.) shown in Table 4 for 1 hour to obtain a granular calcined body. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 1-1 to 1-5. The measurement results are summarized in Table 4.
　各実施例及び比較例の仮焼体をボールミルで２２時間粉砕して、粉砕粉（フェライト粉末）を調製した。比較例１－２０の粉砕粉の比表面積をＢＥＴ法によって測定した。測定結果を表４に併せて示す。なお、表１～４中、「－」は未測定を示す。 The calcined bodies of each Example and Comparative Example were pulverized with a ball mill for 22 hours to prepare pulverized powder (ferrite powder). The specific surface area of the pulverized powder of Comparative Example 1-20 was measured by the BET method. The measurement results are also shown in Table 4. In Tables 1 to 4, “-” indicates unmeasured.
　図２は、実施例１－２の仮焼体をボールミルで湿式粉砕した粉砕粉（Ｓｒフェライト粉末）の電子顕微鏡写真である。この粉砕粉は、粒径が１μｍ以上の粗粒子を含んでいなかった。 FIG. 2 is an electron micrograph of pulverized powder (Sr ferrite powder) obtained by wet pulverizing the calcined body of Example 1-2 with a ball mill. This pulverized powder did not contain coarse particles having a particle size of 1 μm or more.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
［Ｓｒフェライト焼結磁石の作製と評価１］
（実施例２－１～実施例２－３）
　実施例１－２（Ｔ１：９００℃）と同様にして六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。得られた仮焼体におけるＬｉのＬｉ２Ｏ換算の含有量を実施例１－１～１－５と同様にして測定した。その結果、Ｌｉ２Ｏ換算のＬｉ含有量は０．１８質量％であった。 [Production and Evaluation of Sr Ferrite Sintered Magnet 1]
(Example 2-1 to Example 2-3)
A granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained in the same manner as in Example 1-2 (T 1 : 900 ° C.). The content of Li in terms of Li 2 O in the obtained calcined body was measured in the same manner as in Examples 1-1 to 1-5. As a result, the Li content in terms of Li 2 O was 0.18% by mass.
　この仮焼体１３０ｇに対して、ソルビトール、ＳｉＯ２粉末及びＣａＣＯ３粉末を添加した。各添加物の添加量は、仮焼体を基準として、ソルビトールを１質量％、ＳｉＯ２粉末を０．６質量％及びＣａＣＯ３粉末を１．４質量％とした。これらの添加物を添加した後、ボールミルを用いて仮焼体の湿式粉砕を２２時間行ってスラリーを得た。湿式粉砕後の粉砕粉のＢＥＴ法によるＳｒフェライト粉末の比表面積は１２ｍ２／ｇであった。得られたスラリーの固形分（Ｓｒフェライト粉末）の濃度を調整した後、湿式磁場成形機を用いて、１２ｋＯｅの印加磁場中で成形して円柱形状の成形体を得た。この成形体を、大気中、焼結温度Ｔ２（１１６０～１２００℃）で１時間焼成して、実施例２－１～２－３のＳｒフェライト焼結磁石を得た。各実施例の焼結温度Ｔ２は、表５に示すとおりである。 Sorbitol, SiO 2 powder and CaCO 3 powder were added to 130 g of this calcined body. The amount of each additive was 1% by mass of sorbitol, 0.6% by mass of SiO 2 powder, and 1.4% by mass of CaCO 3 powder based on the calcined body. After these additives were added, the calcined body was wet-ground for 22 hours using a ball mill to obtain a slurry. The specific surface area of the Sr ferrite powder by the BET method of the pulverized powder after the wet pulverization was 12 m 2 / g. After adjusting the concentration of the solid content (Sr ferrite powder) of the obtained slurry, it was molded in an applied magnetic field of 12 kOe using a wet magnetic field molding machine to obtain a cylindrical molded body. This molded body was fired in the atmosphere at a sintering temperature T 2 (1160 to 1200 ° C.) for 1 hour to obtain Sr ferrite sintered magnets of Examples 2-1 to 2-3. Sintering temperature T 2 of each example is as shown in Table 5.
　各実施例のＳｒフェライト焼結磁石の上下面を加工した後、最大印加磁場２５ｋＯｅのＢ－Ｈトレーサを用いて磁気特性を測定した。測定では、ＨｃＪ、Ｂｒと４ＰＩｍａｘを求めて、配向度（Ｂｒ／４ＰＩｍａｘ）を算出した。また、Ｓｒフェライト焼結磁石の密度及びＬｉのＬｉ２Ｏ換算の含有量を、それぞれアルキメデス法及び蛍光Ｘ線分析によって測定した。これらの結果を表５に示す。Ｓｒフェライト焼結磁石におけるＬｉの含有量の測定方法は、実施例１－１と同様であり、表５の数値はＬｉ２Ｏ換算の含有量である。 After processing the upper and lower surfaces of the Sr ferrite sintered magnet of each example, the magnetic properties were measured using a BH tracer with a maximum applied magnetic field of 25 kOe. In the measurement, HcJ, Br, and 4PI max were obtained, and the degree of orientation (Br / 4PI max ) was calculated. Further, the density of the sintered Sr ferrite magnet and the content of Li in terms of Li 2 O were measured by Archimedes method and fluorescent X-ray analysis, respectively. These results are shown in Table 5. The method for measuring the Li content in the sintered Sr ferrite magnet is the same as in Example 1-1, and the numerical values in Table 5 are the contents in terms of Li 2 O.
（比較例２－１～比較例２－３）
　比較例１－５（Ｔ１：９００℃）と同様にして六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。得られた仮焼体の磁気特性を実施例２－１～２－３と同様にして測定した。その結果、σｓ：６７．２ｅｍｕ／ｇ、ＨｃＪ：１９８５Ｏｅであった。 (Comparative Examples 2-1 to 2-3)
In the same manner as in Comparative Example 1-5 (T 1 : 900 ° C.), a granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 2-1 to 2-3. As a result, σ s : 67.2 emu / g, HcJ: 1985 Oe.
　このようにして得られた仮焼体を用いたこと以外は、実施例２－１～２－３と同様にして、Ｓｒフェライト焼結磁石を作製した。なお、湿式粉砕後の粉砕粉のＢＥＴ法による比表面積は１２ｍ２／ｇであった。各比較例の焼結温度Ｔ２は、表５に示すとおりである。得られたＳｒフェライト焼結磁石の磁気特性を、実施例２－１～２－３と同様にして測定した。測定結果を表５に示す。 Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used. In addition, the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g. Sintering temperature T 2 of each of the comparative examples are as shown in Table 5. The magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. Table 5 shows the measurement results.
（比較例２－４～比較例２－６）
　比較例１－１２（Ｔ１：９００℃）と同様にして六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。得られた仮焼体の磁気特性を実施例２－１～２－３と同様にして測定した。その結果、σ：５５．９ｅｍｕ／ｇ、ＨｃＪ：１９８５Ｏｅであった。 (Comparative Example 2-4 to Comparative Example 2-6)
In the same manner as in Comparative Example 1-12 (T 1 : 900 ° C.), a granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 2-1 to 2-3. As a result, σ: 55.9 emu / g and HcJ: 1985 Oe.
　このようにして得られた仮焼体を用いたこと以外は、実施例２－１～２－３と同様にして、Ｓｒフェライト焼結磁石を作製した。なお、湿式粉砕後の粉砕粉のＢＥＴ法による比表面積は１２ｍ２／ｇであった。各比較例の焼結温度Ｔ２は、表５に示すとおりである。得られたＳｒフェライト焼結磁石の磁気特性を、実施例２－１～２－３と同様にして測定した。これらの結果を表５に示す。 Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used. In addition, the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g. Sintering temperature T 2 of each of the comparative examples are as shown in Table 5. The magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. These results are shown in Table 5.
（比較例２－７～比較例２－９）
　炭酸リチウム粉末の代わりに炭酸ナトリウム粉末を用いたこと以外は、実施例１－１～１－５と同様にして顆粒状の顆粒状の混合物を得た。炭酸ナトリウム粉末の添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対して、Ｎａ２Ｏ換算で０．４６質量％とした。当該混合物を大気中、仮焼温度Ｔ１（９００℃）で１時間焼成して、顆粒状の仮焼体を得た。得られた仮焼体の磁気特性を実施例２－１～２－３と同様にして測定した。その結果、σ：６７．９ｅｍｕ／ｇであった。 (Comparative Example 2-7 to Comparative Example 2-9)
A granular mixture was obtained in the same manner as in Examples 1-1 to 1-5 except that sodium carbonate powder was used instead of lithium carbonate powder. The amount of sodium carbonate powder added was 0.46% by mass in terms of Na 2 O with respect to the total mass of the Fe 2 O 3 powder and SrCO 3 powder. The mixture was fired in the air at a calcining temperature T 1 (900 ° C.) for 1 hour to obtain a granular calcined body. The magnetic properties of the obtained calcined body were measured in the same manner as in Examples 2-1 to 2-3. As a result, σ was 67.9 emu / g.
　このようにして得られた仮焼体を用いたこと以外は、実施例２－１～２－３と同様にして、Ｓｒフェライト焼結磁石を作製した。なお、湿式粉砕後の粉砕粉のＢＥＴ法による比表面積は１２ｍ２／ｇであった。各比較例の焼結温度Ｔ２は、表５に示すとおりである。得られたＳｒフェライト焼結磁石の磁気特性を、実施例２－１～２－３と同様にして測定した。これらの結果を表５に示す。 Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used. In addition, the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g. Sintering temperature T 2 of each of the comparative examples are as shown in Table 5. The magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. These results are shown in Table 5.
（比較例２－１０～比較例２－１２）
　比較例１－２０（Ｔ１：９５０℃）と同様にして六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。このようにして得られた仮焼体を用いたこと以外は、実施例２－１～２－３と同様にして、Ｓｒフェライト焼結磁石を作製した。なお、湿式粉砕後の粉砕粉のＢＥＴ法による比表面積は１２ｍ２／ｇであった。各比較例の焼結温度Ｔ２は、表５に示すとおりである。得られたＳｒフェライト焼結磁石の磁気特性を、実施例２－１～２－３と同様にして測定した。これらの結果を表５に示す。 (Comparative Example 2-10 to Comparative Example 2-12)
A granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained in the same manner as in Comparative Example 1-20 (T 1 : 950 ° C.). Sr ferrite sintered magnets were produced in the same manner as in Examples 2-1 to 2-3 except that the calcined body thus obtained was used. In addition, the specific surface area by BET method of the pulverized powder after wet pulverization was 12 m 2 / g. Sintering temperature T 2 of each of the comparative examples are as shown in Table 5. The magnetic properties of the obtained Sr ferrite sintered magnet were measured in the same manner as in Examples 2-1 to 2-3. These results are shown in Table 5.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　実施例２－１～２－３のＳｒフェライト焼結磁石は、ＨｃＪが極端に低下することなく、各比較例よりも高い密度、高いＢｒ及び高い配向度を有することが確認された。これは、仮焼前にＬｉを予め添加することによって得られた、微細で高いσｓを有するＳｒフェライト粉末を用いているため、焼結が促進されてこのような高い密度且つ高いＢｒを有するＳｒフェライト焼結磁石が得られたことを示している。 It was confirmed that the sintered Sr ferrite magnets of Examples 2-1 to 2-3 had higher density, higher Br, and higher degree of orientation than those of the comparative examples without extremely decreasing HcJ. This is because the Sr ferrite powder having a fine and high σ s obtained by adding Li in advance before calcination is used, so that the sintering is promoted to have such a high density and a high Br. It shows that an Sr ferrite sintered magnet was obtained.
［Ｓｒフェライト粉末の作製２］
（実施例３－１～３－３，比較例３－１）
　以下の出発原料を準備した。なお、比表面積はＢＥＴ法によって測定された値である。
・Ｆｅ２Ｏ３粉末（比表面積：４．４ｍ２／ｇ）２２０ｇ
・ＳｒＣＯ３粉末（比表面積：５．０ｍ２／ｇ）３５．２３ｇ [Preparation of Sr ferrite powder 2]
(Examples 3-1 to 3-3, Comparative Example 3-1)
The following starting materials were prepared: The specific surface area is a value measured by the BET method.
・ Fe 2 O 3 powder (specific surface area: 4.4 m 2 / g) 220 g
・ SrCO 3 powder (specific surface area: 5.0 m 2 / g) 35.23 g
　上述のＦｅ２Ｏ３粉末及びＳｒＣＯ３粉末を、湿式ボールミルを用いて１６時間粉砕しながら混合してスラリーを得た。このスラリーに、珪酸ナトリウム粉末及び炭酸リチウム粉末を添加した。このときの珪酸ナトリウム粉末及び炭酸リチウム粉末の添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対し、それぞれをＮａ２Ｏ及びＬｉ２Ｏに換算して、０．３８質量％及び０．０９質量％とした。その後、スラリーのスプレー乾燥を行って粒径が約１０μmの顆粒状の混合物を得た。当該混合物を大気中、表６に示す仮焼温度Ｔ１（８００～９５０℃）で１時間焼成して、六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。 The above-mentioned Fe 2 O 3 powder and SrCO 3 powder were mixed while being pulverized for 16 hours using a wet ball mill to obtain a slurry. To this slurry, sodium silicate powder and lithium carbonate powder were added. The addition amount of the sodium silicate powder and the lithium carbonate powder at this time is 0.38% by mass in terms of Na 2 O and Li 2 O, respectively, with respect to the total mass of the Fe 2 O 3 powder and the SrCO 3 powder. It was set to 0.09 mass%. Thereafter, the slurry was spray-dried to obtain a granular mixture having a particle size of about 10 μm. The mixture was fired in the air at a calcining temperature T 1 (800 to 950 ° C.) shown in Table 6 for 1 hour to obtain a granular calcined body containing Sr ferrite having a hexagonal crystal structure.
　得られた仮焼体の磁気特性（飽和磁化及び保磁力）を、実施例１－１と同様にして測定した。その結果を纏めて表６に示す。 The magnetic properties (saturation magnetization and coercive force) of the obtained calcined body were measured in the same manner as in Example 1-1. The results are summarized in Table 6.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
（比較例３－２～３－５）
　炭酸リチウム粉末を添加しなかったこと以外は、比較例３－１及び実施例３－１～３－３と同様にして、Ｓｒフェライト粉末及びＳｒフェライト焼結磁石を作製して評価を行った。珪酸ナトリウム粉末の添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対し、Ｎａ２Ｏに換算して、０．３８質量％とした。評価結果を表７に示す。 (Comparative Examples 3-2 to 3-5)
An Sr ferrite powder and an Sr ferrite sintered magnet were produced and evaluated in the same manner as in Comparative Example 3-1 and Examples 3-1 to 3-3, except that no lithium carbonate powder was added. The amount of sodium silicate powder added was 0.38% by mass in terms of Na 2 O with respect to the total mass of Fe 2 O 3 powder and SrCO 3 powder. Table 7 shows the evaluation results.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　表６及び表７に示す結果から、リチウム化合物とナトリウム化合物の両方を添加した場合の方が、ナトリウム化合物のみを添加した場合よりも、低い仮焼温度で高いσｓを有する仮焼体が得られることが確認された。 From the results shown in Table 6 and Table 7, a calcined body having a higher σ s at a lower calcining temperature is obtained when both the lithium compound and the sodium compound are added than when only the sodium compound is added. It was confirmed that
［Ｓｒフェライト焼結磁石の作製と評価２］
（実施例４－１～実施例４－６）
　実施例３－１（Ｔ１：８５０℃）と同様にして六方晶構造を有するＳｒフェライトを含む顆粒状の仮焼体を得た。この仮焼体１３０ｇに対して、ソルビトール、ＳｉＯ２粉末及びＣａＣＯ３粉末を添加した。各添加物の添加量は、仮焼体を基準として、ソルビトールを１質量％、ＳｉＯ２粉末を０．４質量％及びＣａＣＯ３粉末を０．９質量％とした。これらの添加物を添加した後、ボールミルを用いて仮焼体の湿式粉砕を行ってスラリーを得た。湿式粉砕の時間及び湿式粉砕後のＢＥＴ法によるＳｒフェライト粉末の比表面積は表８に示すとおりである。 [Production and Evaluation of Sr Ferrite Sintered Magnet 2]
(Example 4-1 to Example 4-6)
In the same manner as in Example 3-1 (T 1 : 850 ° C.), a granular calcined body containing Sr ferrite having a hexagonal crystal structure was obtained. Sorbitol, SiO 2 powder and CaCO 3 powder were added to 130 g of this calcined body. The amount of each additive was 1% by mass of sorbitol, 0.4% by mass of SiO 2 powder, and 0.9% by mass of CaCO 3 powder based on the calcined body. After adding these additives, the calcined body was wet-ground using a ball mill to obtain a slurry. Table 8 shows the wet pulverization time and the specific surface area of the Sr ferrite powder by the BET method after the wet pulverization.
　得られたスラリーの固形分（Ｓｒフェライト粉末）の濃度を調整した後、湿式磁場成形機を用いて、１２ｋＯｅの印加磁場中で成形して円柱形状の成形体を得た。この成形体を、大気中、焼結温度Ｔ２（１１４０～１１８０℃）で１時間焼成して、実施例４－１～４－６のＳｒフェライト焼結磁石を得た。各実施例の焼結温度Ｔ２は、表８に示すとおりである。各実施例のＳｒフェライト焼結磁石の磁気特性及び密度を実施例２－１～２－３と同様にして測定した。これらの結果を表８に示す。 After adjusting the concentration of the solid content (Sr ferrite powder) of the obtained slurry, it was molded in an applied magnetic field of 12 kOe using a wet magnetic field molding machine to obtain a cylindrical molded body. This molded body was fired in the atmosphere at a sintering temperature T 2 (1140 to 1180 ° C.) for 1 hour to obtain Sr ferrite sintered magnets of Examples 4-1 to 4-6. Sintering temperature T 2 of each example is as shown in Table 8. The magnetic properties and density of the Sr ferrite sintered magnet of each example were measured in the same manner as in Examples 2-1 to 2-3. These results are shown in Table 8.
（比較例４－１～４－６）
　炭酸リチウム粉末を添加しなかったこと以外は、実施例４－１～４－６と同様にして、Ｓｒフェライト粉末及びＳｒフェライト焼結磁石を作製して評価を行った。珪酸ナトリウム粉末の添加量は、Ｆｅ２Ｏ３粉末及びＳｒＣＯ３粉末の合計質量に対し、Ｎａ２Ｏに換算して、０．３８質量％とした。評価結果を表８に纏めて示す。 (Comparative Examples 4-1 to 4-6)
Sr ferrite powders and Sr ferrite sintered magnets were produced and evaluated in the same manner as in Examples 4-1 to 4-6 except that the lithium carbonate powder was not added. The amount of sodium silicate powder added was 0.38% by mass in terms of Na 2 O with respect to the total mass of Fe 2 O 3 powder and SrCO 3 powder. The evaluation results are summarized in Table 8.
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
　焼結温度Ｔ２が１１６０℃の場合で比較すると、炭酸リチウム粉末を添加した実施例４－１～４－６のＳｒフェライト焼結磁石は、ＨｃＪが極端に低下することなく、各比較例のＳｒフェライト焼結磁石よりも、高いＢｒ及び高い配向度を有していた。実施例４－１～４－６の方が、各比較例よりも密度が高いことから、リチウムの添加によって、焼結性が向上していることが確認された。また、実施例４－１及び４－４では、焼結温度Ｔ２を１１４０℃と低くしても、焼結が十分に進行して、高いＢｒ及び高い配向度を有するＳｒフェライト焼結磁石が得られることが確認された。 Comparing when the sintering temperature T 2 is 1160 ° C., the Sr ferrite sintered magnets of Examples 4-1 to 4-6 to which lithium carbonate powder was added had no HcJ drastically reduced. It had higher Br and higher degree of orientation than Sr ferrite sintered magnet. In Examples 4-1 to 4-6, the density was higher than that of each of the comparative examples. Therefore, it was confirmed that the sinterability was improved by the addition of lithium. Further, in Examples 4-1 and 4-4, even when the sintering temperature T 2 was lowered to 1140 ° C., the sintering proceeded sufficiently, and the Sr ferrite sintered magnet having a high Br and a high degree of orientation was obtained. It was confirmed that it was obtained.
　本発明によれば、高いＢｒを有するＳｒフェライト焼結磁石を、簡便な工程で製造することが可能なＳｒフェライト焼結磁石の製造方法を提供することができる。また、高い磁気特性と高い信頼性を有するＳｒフェライト焼結磁石を提供することができる。さらに、高い効率と高い信頼性を有するモータ及び発電機を提供することができる。 According to the present invention, it is possible to provide a method for producing an Sr ferrite sintered magnet capable of producing an Sr ferrite sintered magnet having a high Br by a simple process. In addition, a sintered Sr ferrite magnet having high magnetic properties and high reliability can be provided. Furthermore, it is possible to provide a motor and a generator having high efficiency and high reliability.
　１０…フェライト焼結磁石、３０…モータ、３１…ハウジング、３２…ロータ、３３…ブラケット、３４，３５…軸受、３６…ロータ軸、３７…ロータコア。
  DESCRIPTION OF SYMBOLS 10 ... Ferrite sintered magnet, 30 ... Motor, 31 ... Housing, 32 ... Rotor, 33 ... Bracket, 34, 35 ... Bearing, 36 ... Rotor shaft, 37 ... Rotor core.

Claims (8)

  1. 　鉄化合物の粉末、ストロンチウム化合物の粉末、及び、構成元素としてＬｉを有する化合物の粉末を含む混合物を、８５０～１０５０℃で焼成して、六方晶構造を有するＳｒフェライトを含み、ＬｉをＬｉ２Ｏに換算して０．０１～０．５質量％含有する仮焼体を得る仮焼工程を有する、仮焼体又はその粉砕粉を含むＳｒフェライト粉末の製造方法。 A mixture containing an iron compound powder, a strontium compound powder, and a compound powder containing Li as a constituent element is fired at 850 to 1050 ° C. to contain Sr ferrite having a hexagonal crystal structure, and Li is added to Li 2 O. A method for producing a Sr ferrite powder containing a calcined body or a pulverized powder thereof, comprising a calcining step for obtaining a calcined body containing 0.01 to 0.5% by mass in terms of
  2. 　前記仮焼体を粉砕してＳｒフェライトを含む粉砕粉を得る粉砕工程を有する、請求項１に記載のＳｒフェライト粉末の製造方法。 The method for producing Sr ferrite powder according to claim 1, further comprising a pulverizing step of pulverizing the calcined body to obtain a pulverized powder containing Sr ferrite.
  3. 　前記仮焼体のＢＥＴ法による比表面積が２ｍ２／ｇ以上であり、飽和磁化が６７ｅｍｕ／ｇ以上である、請求項１又は２に記載のＳｒフェライト粉末の製造方法。 The method for producing Sr ferrite powder according to claim 1 or 2, wherein the calcined body has a specific surface area by BET method of 2 m 2 / g or more and a saturation magnetization of 67 emu / g or more.
  4. 　前記混合物が、構成元素としてＮａを有する化合物の粉末を含む、請求項１～３のいずれか一項に記載のＳｒフェライト粉末の製造方法。 The method for producing Sr ferrite powder according to any one of claims 1 to 3, wherein the mixture contains a powder of a compound having Na as a constituent element.
  5. 　鉄化合物の粉末、ストロンチウム化合物の粉末、及び、構成元素としてＬｉを有する化合物の粉末を含む混合物を、８５０～１０５０℃で焼成して、六方晶構造を有するＳｒフェライトを含み、ＬｉをＬｉ２Ｏに換算して０．０１～０．５質量％含有する仮焼体を得る仮焼工程と、
    　前記仮焼体を粉砕してＳｒフェライトを含む粉砕粉を得る粉砕工程と、
    　前記粉砕粉を磁場中成形して成形体を得る成形工程と、
    　前記成形体を１０００～１２５０℃で焼成して、Ｓｒフェライト焼結磁石を得る焼結工程と、を有する、Ｓｒフェライト焼結磁石の製造方法。     A mixture containing an iron compound powder, a strontium compound powder, and a compound powder containing Li as a constituent element is fired at 850 to 1050 ° C. to contain Sr ferrite having a hexagonal crystal structure, and Li is added to Li 2 O. A calcining step of obtaining a calcined body containing 0.01 to 0.5% by mass in terms of
    Crushing the calcined body to obtain a pulverized powder containing Sr ferrite;
    A molding step of molding the pulverized powder in a magnetic field to obtain a molded body;
    And sintering the molded body at 1000 to 1250 ° C. to obtain a Sr ferrite sintered magnet.
  6. 　前記混合物が、構成元素としてＮａを有する化合物の粉末を含む、請求項５に記載のＳｒフェライト焼結磁石の製造方法。 The method for producing a sintered Sr ferrite magnet according to claim 5, wherein the mixture includes a powder of a compound having Na as a constituent element.
  7. 　請求項５又は６に記載の製造方法で得られるＳｒフェライト焼結磁石を備えるモータ。 A motor comprising an Sr ferrite sintered magnet obtained by the manufacturing method according to claim 5 or 6.
  8. 　請求項５又は６に記載の製造方法で得られるＳｒフェライト焼結磁石を備える発電機。
          A generator provided with the sintered Sr ferrite magnet obtained by the manufacturing method according to claim 5 or 6.
PCT/JP2013/077837 2012-10-11 2013-10-11 Sr ferrite powder, method for manufacturing sr ferrite sintered magnet, motor, and generator WO2014058067A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201380040883.2A CN104507889A (en) 2012-10-11 2013-10-11 Sr ferrite powder, method for manufacturing Sr ferrite sintered magnet, motor, and generator
JP2014540917A JPWO2014058067A1 (en) 2012-10-11 2013-10-11 Method for producing Sr ferrite powder and sintered Sr ferrite magnet, motor and generator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012-226222 2012-10-11
JP2012226222 2012-10-11

Publications (1)

Publication Number Publication Date
WO2014058067A1 true WO2014058067A1 (en) 2014-04-17

Family

ID=50477528

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/077837 WO2014058067A1 (en) 2012-10-11 2013-10-11 Sr ferrite powder, method for manufacturing sr ferrite sintered magnet, motor, and generator

Country Status (3)

Country Link
JP (1) JPWO2014058067A1 (en)
CN (1) CN104507889A (en)
WO (1) WO2014058067A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2017170427A1 (en) * 2016-03-31 2019-02-07 パウダーテック株式会社 Ferrite powder, resin composition and molded body
TWI706151B (en) * 2019-08-14 2020-10-01 中國鋼鐵股份有限公司 Magnetic evaluation method of permanent magnetic ferrite magnet

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107473724A (en) * 2017-07-27 2017-12-15 中钢天源(马鞍山)通力磁材有限公司 A kind of preparation method and product of high-performance M types calcium strontium ferrite
CN107721405B (en) * 2017-11-16 2020-08-11 安徽鑫磁源磁业有限公司 Preparation of M-type strontium ferrite SrFe through low-temperature calcination12O19Method for pre-firing materials
CN110323025B (en) * 2018-03-28 2021-12-10 Tdk株式会社 Ferrite sintered magnet

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5217694A (en) * 1975-07-31 1977-02-09 Daido Steel Co Ltd Magnet made of sintered oxide
JPS52126795A (en) * 1976-04-17 1977-10-24 Daido Steel Co Ltd Method of manufacturing oxide sintered permanent magnet

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5217694A (en) * 1975-07-31 1977-02-09 Daido Steel Co Ltd Magnet made of sintered oxide
JPS52126795A (en) * 1976-04-17 1977-10-24 Daido Steel Co Ltd Method of manufacturing oxide sintered permanent magnet

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2017170427A1 (en) * 2016-03-31 2019-02-07 パウダーテック株式会社 Ferrite powder, resin composition and molded body
EP3438055A4 (en) * 2016-03-31 2019-12-04 Powdertech Co., Ltd. Ferrite powder, resin composition, and molded article
TWI706151B (en) * 2019-08-14 2020-10-01 中國鋼鐵股份有限公司 Magnetic evaluation method of permanent magnetic ferrite magnet

Also Published As

Publication number Publication date
JPWO2014058067A1 (en) 2016-09-05
CN104507889A (en) 2015-04-08

Similar Documents

Publication Publication Date Title
JP6156372B2 (en) Method for producing Sr ferrite particles for sintered magnet, method for using Sr ferrite particles, Sr ferrite sintered magnet and method for producing the same, motor and generator
JP6596828B2 (en) Ferrite sintered magnet and motor including the same
JP5733463B2 (en) Ferrite sintered magnet and motor including the same
JP6769482B2 (en) Ferrite magnet
JP5733464B2 (en) Ferrite sintered magnet and motor including the same
WO2014058067A1 (en) Sr ferrite powder, method for manufacturing sr ferrite sintered magnet, motor, and generator
WO2014017637A2 (en) MANUFACTURING METHOD FOR Sr FERRITE PARTICLES FOR SINTERED MAGNET, AND MANUFACTURING METHOD FOR Sr FERRITE SINTERED MAGNET
WO2014087932A1 (en) METHOD FOR PRODUCING Sr FERRITE SINTERED MAGNET
JP6596829B2 (en) Ferrite sintered magnet and motor including the same
JP6488892B2 (en) Sr ferrite sintered magnet, motor and generator
US20070023970A1 (en) Method for producing ferrite sintered magnet
KR100737330B1 (en) Ferrite magnetic material and ferrite sintered magnet
WO2014017551A1 (en) METHOD FOR PRODUCING Sr FERRITE SINTERED MAGNET, MOTOR AND POWER GENERATOR
JP4720994B2 (en) Ferrite magnetic material manufacturing method
JP4709338B2 (en) Method for producing hexagonal ferrite magnet powder and hexagonal ferrite sintered magnet
WO2014174876A1 (en) Manufacturing method for sr-ferrite sintered magnet, as well as motor and electrical power generator provided with sr-ferrite sintered magnet
JP4591684B2 (en) Ferrite magnetic material and manufacturing method thereof
JP6863374B2 (en) Ferrite magnet
JP6488675B2 (en) Sr ferrite sintered magnet, motor and generator
JP2007031203A (en) Method for manufacturing w-type ferrite magnet

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: 13845647

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2014540917

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13845647

Country of ref document: EP

Kind code of ref document: A1