TW202242157A - Method for manufacturing iron (Fe)-nickel (Ni) alloy powder - Google Patents

Abstract

Provided is a method for manufacturing an iron-nickel alloy powder that has superior powder characteristics and magnetization characteristics. This method is a method for manufacturing an iron (Fe)-nickel (Ni) alloy powder that includes at least iron (Fe) and nickel (Ni) as magnetic metals. This method comprises the following steps: a preparation step in which a magnetic metal source, a nucleating agent, a complexing agent, a reducing agent, and a pH adjusting agent are prepared as starting materials; a crystallization step in which a reaction liquid that includes the starting materials and water is produced, and a crystallized powder that includes the magnetic metals is made to crystallize in the reaction liquid by a reduction reaction; and a recovery step in which the crystallized powder is recovered from the reaction liquid. The magnetic metal source includes a water-soluble iron salt and a water-soluble nickel salt, the nucleating agent is a water-soluble salt of a metal that is more noble than nickel, and the complexing agent is at least one type of substance selected from the group consisting of a hydroxy carboxylic acid, a salt of a hydroxy carboxylic acid, and a derivative of a hydroxy carboxylic acid. The reducing agent is hydrazine (N2H4), and the pH adjusting agent is an alkali hydroxide.

Description

Method for producing iron (Fe)-nickel (Ni)-based alloy powder, iron (Fe)-nickel (Ni)-based alloy powder, compacted powder or sheet containing said alloy powder, and inductor comprising said compacted powder or sheet Reactor, reactor, choke coil, noise filter, transformer, rotating machine, generator, or radio wave absorber

The present invention relates to a method for producing iron (Fe)-nickel (Ni) alloy powder, iron (Fe)-nickel (Ni) alloy powder, pressed powder body or sheet containing the above alloy powder, and the above-mentioned compressed powder Body or chip inductors, reactors, choke coils, noise filters, transformers, rotating machines, generators, or radio wave absorbers.

Iron-nickel alloys known as permalloys are soft magnetic materials with high magnetic permeability and are used in the cores of magnetic parts such as choke coils and inductors. In particular, iron-nickel alloy powder is used as a material for powder cores for magnetic cores (powder cores) obtained by compression molding the same.

As for the mus alloys, various mus alloys such as 78 mus alloys ( mus alloys A ) and 45 mus alloys are known, and they are used according to their magnetic properties or applications. 78 high magnetic permeability alloy is an iron-nickel alloy with a nickel content of about 78.5% by mass, and has the characteristics of high magnetic permeability. 45 High magnetic permeability alloy is an iron-nickel alloy with a nickel content of 45% by mass. Although the magnetic permeability is slightly lower, it has the characteristics of a higher saturation magnetic flux density.

In recent years, the miniaturization and high performance of mobile devices such as notebook computers and smart phones are rapidly developing. In addition to this, magnetic components such as inductors have been required to cope with higher frequencies in addition to improved magnetic characteristics. Therefore, for the material of the powder core, while requiring a higher magnetic flux density, it is also required to reduce the loss. Regarding loss, there are mainly hysteresis loss and eddy current loss. In order to suppress the hysteresis loss, it is effective to reduce the coercive force of the alloy powder. On the other hand, in order to suppress eddy current loss, it is effective to apply a thinner insulating coating to the particle surface of the alloy powder, thereby reducing the eddy current between the particles; or to make the alloy powder finer and the particle size distribution smaller. The reason for this is that if there are coarse particles, eddy currents tend to flow therein, causing losses due to Joule heat.

Dry methods such as an atomization method, a vapor phase reduction method, and a dry reduction method are conventionally known as methods for producing fine alloy powders. The atomization method is a method of blowing water or gas to the molten metal to rapidly cool and solidify the molten metal. The gas phase reduction method is a method of hydrogen reduction of metal halides in the gas phase state. The dry reduction method is a method of reducing metal oxides using a reducing agent.

For example, according to records in Patent Document 1, Ni-Fe alloy powders used as materials for noise filters, choke coils, inductors, etc. are produced by vapor phase reduction ([0001 of Patent Document 1] ] and [0014]). Also, according to the description in Patent Document ₁ , a mixture _of NiCl and FeCl is heated to obtain vaporized chloride, and the chloride is contacted with hydrogen to cause a reduction reaction, thereby producing a fine powder of Ni-Fe alloy (patent document 1). [0016] of Document 1). Also, according to Patent Document 2, Fe-Ni alloy powder used as a material for electronic components such as choke coils or inductors is produced by reducing oxides of Fe and Ni in a reducing gas ( Claim 1 of Patent Document 2).

On the other hand, the industry has proposed the use of wet methods to produce finer alloy powders. For example, Patent Document 3 discloses a method for producing nickel-iron alloy nanoparticles, which is characterized in that: adding a reducing agent such as hydrazine to an aqueous solution containing nickel salts and iron salts, the nickel ions and iron ions contained in the aqueous solution Simultaneous reduction is performed to generate nickel-iron alloy nanoparticles (claims 1 to 6 of Patent Document 3). Also, it is considered that by this production method, nickel-iron alloy nanoparticles can be efficiently produced on an industrial scale and at low production costs. The nickel-iron alloy nanoparticles are suitable as fillers for imparting magnetic properties, and the average primary particle size is 200. nm or less ([0015] of Patent Document 3). [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-193160 [Patent Document 2] Japanese Unexamined Patent Publication No. 2012-197474 [Patent Document 3] Japanese Patent Laid-Open No. 2008-024961

[Problem to be Solved by the Invention]

Although it is proposed to produce fine alloy powder by dry method or wet method, there is still room for improvement in the prior art in obtaining alloy powder with excellent powder properties. For example, alloy powder produced by the atomization method has a relatively large average particle size of several μm or more, which does not fully meet the requirements for miniaturization. In addition, according to the vapor phase reduction method proposed in Patent Document 1, the obtained alloy powder has a wide particle size distribution. Therefore, the alloy powder contains coarse particles, which are insufficient to reduce the eddy current loss. In addition, there is also a problem that the composition and particle size of the alloy powder are not stable. The dry reduction method proposed in Patent Document 2 requires high-temperature heating, so there is a problem that the obtained alloy powder is easily sintered to form coarse aggregated particles.

The wet method proposed in Patent Document 3 is different from the dry method in that the reduction reaction is carried out at a low temperature, so it has the advantage that coarse aggregated particles are less likely to be formed. Also, even if aggregated particles are formed, the aggregated particles are easily disintegrated because the particles are not firmly bonded to each other. However, in the method proposed in Patent Document 3, a large amount of hydrazine is used as a reducing agent. Therefore, the cost of the reducing agent is greatly increased, so it is not practical. Also, it is difficult to say that the particle size distribution of the obtained alloy powder is sufficiently small.

The inventors of the present invention have conducted diligent research in view of such conventional problems. As a result, it was found that by using specific nucleating agents and complexing agents when producing iron-nickel alloy powders by a wet method, alloy powders excellent in powder properties and magnetic properties can be obtained. In addition, the following insights were also obtained, that is, when the content ratio of iron is relatively large, if a predetermined content ratio of cobalt is added, it can be used with a very small amount of reducing agent due to the reduction reaction acceleration and spheroidization acceleration of cobalt. Spherical alloy powder with less agglomeration, smooth surface and higher saturation magnetic flux density can be obtained.

The present invention was completed based on such knowledge, and an object of the present invention is to provide a method for producing iron-nickel alloy powder having excellent powder properties and magnetic properties. [Technical means to solve the problem]

The present invention includes aspects of the following (1) to (40). Furthermore, in this specification, the expression of "~" includes the numerical values at both ends. That is, "X to Y" is synonymous with "more than X and less than Y".

(1) A method for producing an iron (Fe)-nickel (Ni) alloy powder, the iron (Fe)-nickel (Ni) alloy powder containing at least iron (Fe) and nickel (Ni) as magnetic metals, the method Including the following steps: a preparation step, which prepares a magnetic metal source, a nucleating agent, a complexing agent, a reducing agent, and a pH regulator as starting materials; a crystallization step, which prepares a reaction solution comprising the above starting materials and water, and Crystallization of the crystallization powder containing the above-mentioned magnetic metal by reduction reaction in the above-mentioned reaction liquid; and a recovery step, which recovers the above-mentioned crystallization powder from the above-mentioned reaction liquid; and the above-mentioned magnetic metal source includes a water-soluble iron salt and a water-soluble nickel salt , the above-mentioned nucleating agent is a water-soluble salt of a metal that is biased towards the noble metal side than nickel, and the above-mentioned complexing agent is at least one selected from the group consisting of hydroxycarboxylic acid, a salt of hydroxycarboxylic acid, and a derivative of hydroxycarboxylic acid, The reducing agent is hydrazine (N ₂ H ₄ ), and the pH regulator is an alkali metal hydroxide.

(2) The method of (1) above, wherein the water-soluble iron salt is selected from ferrous chloride (FeCl ₂ ), ferrous sulfate (FeSO ₄ ), and ferrous nitrate (Fe(NO ₃ ) ₂ ) at least one of the group formed.

(3) The method of (1) or (2) above, wherein the above-mentioned water-soluble nickel salt is selected from nickel chloride (NiCl ₂ ), nickel sulfate (NiSO ₄ ), and nickel nitrate (Ni(NO ₃ ) ₂ ) at least one of the group consisting of.

(4) The method according to any one of (1) to (3) above, wherein the nucleating agent is at least one selected from the group consisting of copper salts, palladium salts, and platinum salts.

(5) The method according to any one of the above (1) to (4), wherein the complexing agent is selected from tartaric acid ((CH(OH)COOH) ₂ ) and citric acid (C(OH)(CH ₂ COOH) ) ₂ COOH) at least one hydroxycarboxylic acid.

(6) The method according to any one of (1) to (5) above, wherein the pH adjuster is at least one selected from sodium hydroxide (NaOH) and potassium hydroxide (KOH).

(7) The method according to any one of the above (1) to (6), wherein the magnetic metal further contains cobalt (Co), The aforementioned magnetic metal source further includes a water-soluble cobalt salt.

(8) The method according to (7) above, wherein, in the above-mentioned magnetic metal, the content ratio of iron (Fe) is not less than 60 mol % and not more than 85 mol %, and the content ratio of cobalt (Co) is 10 mol % % above 30 mole%, In the above-mentioned magnetic metal source, the content ratio of the water-soluble iron salt is not less than 60 mol% and not more than 85 mol%, and the content ratio of the water-soluble cobalt salt is not less than 10 mol% and not more than 30 mol%.

(9) The method according to (7) or (8) above, wherein the water-soluble cobalt salt is selected from cobalt chloride (CoCl ₂ ), cobalt sulfate (CoSO ₄ ), and cobalt nitrate (Co(NO ₃ ) ₂ ) at least one of the group consisting of.

(10) The method according to any one of the above (1) to (9), wherein the above-mentioned starting material further includes the following amine compound containing two or more primary amino groups (-NH ₂ ) in the molecule , 1 primary amine group (-NH ₂ ) and 1 or more secondary amine groups (-NH-), or 2 or more secondary amine groups (-NH-).

(11) The method according to (10) above, wherein the amine compound is at least one of alkylene amines and alkylene amine derivatives.

(12) The method according to (11) above, wherein the above-mentioned alkylene amine and/or alkylene amine derivative has at least one nitrogen atom of the amine group in the molecule bonded together via a carbon chain having 2 carbon atoms. The structure represented by (A) below.

(13) The method according to any one of (10) to (12) above, wherein the amine compound is selected from the group consisting of ethylenediamine (H ₂ NC ₂ H ₄ NH ₂ ), diethylenetriamine (H ₂ NC ₂ H ₄ NHC ₂ H ₄ NH ₂ ), triethylenetetramine (H ₂ N(C ₂ H ₄ NH) ₂ C ₂ H ₄ NH ₂ ), tetraethylenepentamine (H ₂ N(C ₂ H ₄ NH) ₃ C ₂ H ₄ NH ₂ ), pentaethylenehexamine (H ₂ N(C ₂ H ₄ NH) ₄ C ₂ H ₄ NH ₂ ), and propylenediamine (CH ₃ CH(NH ₂ ) At least one alkylene amine in the group consisting of CH ₂ NH ₂ ), and/or selected from tris(2-aminoethyl)amine (N(C ₂ H ₄ NH ₂ ) ₃ ), N- (2-aminoethyl)ethanolamine (H ₂ NC ₂ H ₄ NHC ₂ H ₄ OH), N-(2-aminoethyl)propanolamine (H ₂ NC ₂ H ₄ NHC ₃ H ₆ OH), 2,3-diaminopropionic acid (H ₂ NCH ₂ CH(NH)COOH), ethylenediamine-N,N'-diacetic acid (HOOCCH ₂ NHC ₂ H ₄ NHCH ₂ COOH), and 1,2-cyclo At least one alkylene amine derivative from the group consisting of hexanediamine (H ₂ NC ₆ H ₁₀ NH ₂ ).

(14) The method according to any one of (10) to (13) above, wherein the blending amount of the amine compound is not less than 0.01 mol % and not more than 5.00 mol % relative to the total amount of the above-mentioned magnetic metals.

(15) The method according to any one of the above (1) to (14), wherein, when preparing the reaction liquid in the above-mentioned crystallization step, the above-mentioned magnetic metal source, the above-mentioned nucleating agent, and the above-mentioned complexing agent are respectively prepared to dissolve The raw material solution of metal salt in water, the reducing agent solution obtained by dissolving the reducing agent in water, and the pH adjusting solution obtained by dissolving the pH adjusting agent in water, the above metal salt raw material solution and the pH adjusting The solutions are mixed to form a mixed solution, and the mixed solution and the reducing agent solution are mixed.

(16) The method according to (15) above, wherein, when preparing the reaction solution, the pH adjustment solution and the reducing agent solution are sequentially added to the metal salt raw material solution and mixed.

(17) The method according to (15) or (16) above, wherein the time required for mixing the mixed solution and the reducing agent solution is 1 second to 180 seconds.

(18) The method according to any one of the above-mentioned (1) to (14), wherein, when preparing the reaction solution in the above-mentioned crystallization step, the above-mentioned magnetic metal source, the above-mentioned nucleating agent, and the above-mentioned complexing agent are separately prepared to dissolve A metal salt raw material solution in water, and a reducing agent solution obtained by dissolving the reducing agent and the pH adjusting agent in water. The metal salt raw material solution and the reducing agent solution are mixed.

(19) The method according to the above (18), wherein, when preparing the above-mentioned reaction liquid, the above-mentioned reducing agent solution is added to the above-mentioned metal salt raw material solution, or conversely, the above-mentioned metal salt raw material solution is added to the above-mentioned reducing agent solution and mixed .

(20) The method according to (18) or (19) above, wherein the time required for mixing the metal salt raw material solution and the reducing agent solution is from 1 second to 180 seconds.

(21) The method according to any one of the above-mentioned (1) to (20), wherein, in the above-mentioned crystallization step, before the completion of the reduction reaction, the above-mentioned water-soluble nickel salt and the above-mentioned water-soluble nickel salt are further added to the above-mentioned reaction solution. An additional raw material solution obtained by dissolving at least one of the active cobalt salts in water is mixed.

(22) The method according to any one of (15) to (21) above, wherein an amine compound is blended into at least one of the above-mentioned metal salt raw material solution, the above-mentioned reducing agent solution, the above-mentioned pH adjustment solution, and the reaction solution .

(23) The method according to any one of (1) to (22) above, wherein the temperature of the reaction solution (reaction initiation temperature) at the start of crystallization of the crystallization powder is 40°C to 90°C, and The temperature of the reaction liquid held during the crystallization after the start of the crystallization (reaction holding temperature) is 60°C or higher and 99°C or lower.

(24) The method according to any one of the above (1) to (23), which further includes a crushing step, which is to use collision to the crystallization powder after the recovery step or the crystallization powder on the way to the recovery step The disintegration treatment of energy disintegrates the aggregated particles contained in the crystallization powder.

(25) The method of (24) above, wherein the crystallization powder after the recovery step is crushed by dry crushing or wet crushing, or the crystallization powder on the way to the recovery step is crushed by wet crushing Disintegrate.

(26) The method according to (25) above, wherein the dry disintegration is a spiral jet disintegration.

(27) The method according to (25) above, wherein the above-mentioned wet disintegration is high-pressure fluid collision disintegration.

(28) The method according to any one of the above (1) to (27), which further includes a high-temperature heat treatment step. The high-temperature heat treatment step is to treat the crystallization powder after the recovery step or the crystallization powder on the way to the recovery step in a non- Heat treatment over 150°C and below 400°C is carried out in an active environment, a reducing environment, or a vacuum environment, thereby improving the composition uniformity within the particles of the iron (Fe)-nickel (Ni) alloy powder.

(29) The method according to any one of (1) to (28) above, which further includes an insulating coating step. The insulating coating step is to perform insulating coating treatment on the crystallization powder obtained through the recovery step, and The surface of the particles of the crystallized powder forms an insulating coating made of metal oxides, thereby improving the insulation between the particles.

(30) The method according to (29) above, wherein, in the insulating coating step, the crystallized powder is dispersed in a mixed solvent containing water and an organic solvent, and the metal alkoxide is added and mixed into the mixed solvent Prepare a slurry in the above slurry, hydrolyze and dehydrate the metal alkoxide in the above slurry to form an insulating coating made of metal oxide on the particle surface of the crystallization powder, and then recover it from the above slurry to form Crystallization powder with insulating coating.

(31) The method according to (30) above, wherein the metal alkoxide contains silane oxide (alkyl silicate) as a main component, and the metal oxide contains silicon dioxide (SiO ₂ ) as a main component.

(32) The method of (30) or (31) above, wherein the hydrolysis of the metal alkoxide is carried out in the presence of an alkali catalyst (alkali catalyst).

(33) An iron (Fe)-nickel (Ni) alloy powder produced by the method of any one of the above (1) to (32).

(34) An alloy powder which is an iron (Fe)-nickel (Ni) alloy powder containing at least iron (Fe) and nickel (Ni) as a magnetic metal, and has an average particle size of 0.10 μm or more and 0.60 μm or less, according to The coefficient of variation (CV value) obtained from the average particle size and standard deviation in the number particle size distribution according to the following formula (1) shall be 25% or less. CV value (%) = standard deviation of particle size / average particle size × 100 ···(1)

(35) The alloy powder according to (34) above, which further contains cobalt (Co) as the magnetic metal.

(36) The alloy powder of (34) or (35) above, wherein the iron (Fe) content is 10 mol% to 95 mol%, and the nickel (Ni) content is 5 mol% to 90 mol% or less, and the amount of cobalt (Co) is not less than 0 mol % and not more than 40 mol %.

(37) The alloy powder according to (34) or (35) above, which has a crystallite diameter of 30 nm or less.

(38) The alloy powder of (34) or (35) above, which has a saturation magnetic flux density of 1 T (Tesla) or more and a coercive force of 2000 A/m or less.

(39) A compact or sheet comprising the alloy powder according to any one of (33) to (38) above.

(40) An inductor, a reactor, a choke coil, a noise filter, a transformer, a rotary machine, a generator, or a radio wave absorber, comprising the powdered body and/or sheet of (39) above. [Effect of Invention]

According to the present invention, there is provided a method for producing iron-nickel alloy powder having excellent powder properties and magnetic properties.

A specific embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described. In addition, this invention is not limited to the following embodiment, Various changes are possible in the range which does not change the summary of this invention.

<<1. Method for producing iron-nickel alloy powder>> The method for producing iron (Fe)-nickel (Ni) alloy powder in this embodiment includes the following steps: preparation step, which includes magnetic metal source, nucleation The starting material of agent, complexing agent, reducing agent, and pH adjusting agent; crystallization step, it prepares the reaction liquid that comprises this starting material and water, makes the crystal that comprises above-mentioned magnetic metal by reduction reaction in this reaction liquid powder and crystallization; and a recovery step, which recovers the crystallization powder from the obtained reaction liquid. Here, the iron (Fe)-nickel (Ni) alloy powder contains at least iron (Fe) and nickel (Ni) as magnetic metals. Also, the magnetic metal source includes water-soluble iron salts and water-soluble nickel salts. The nucleating agent is a water-soluble salt of a metal that is more precious than nickel. The complexing agent is at least one selected from the group consisting of hydroxycarboxylic acids, salts of hydroxycarboxylic acids, and derivatives of hydroxycarboxylic acids. The reducing agent is hydrazine (N ₂ H ₄ ).

The iron (Fe)-nickel (Ni) alloy powder (hereinafter, may be simply referred to as “alloy powder”) of the present embodiment contains at least iron (Fe) and nickel (Ni). Moreover, the alloy powder may contain cobalt (Co) as needed. That is, the alloy powder may be an iron-nickel alloy powder containing only iron and nickel, or may be an iron-nickel-cobalt alloy powder containing iron, nickel, and cobalt. Iron, nickel and cobalt are all magnetic metals exhibiting ferromagnetism. Therefore, the iron-nickel alloy powder or iron-nickel-cobalt alloy powder has a high saturation magnetic flux density and excellent magnetic properties. In addition, in this specification, a magnetic metal is a general term of iron, nickel, and cobalt. That is, when the alloy does not contain cobalt, the magnetic metal is a general term for iron and nickel, and when the alloy contains cobalt, it is a general term for iron, nickel, and cobalt.

The ratios of iron (Fe), nickel (Ni) and cobalt (Co) contained in the alloy powder of this embodiment are not particularly limited. The amount of iron may be not less than 10 mol% and not more than 95 mol%, may be not less than 25 mol% and not more than 90 mol%, and may be not less than 40 mol% and not more than 80 mol%. Also, the amount of nickel may be 5-90 mol%, 10-75 mol%, or 20-60 mol%. The amount of cobalt may be not less than 0 mol% and not more than 40 mol%, and may be not less than 5 mol% and not more than 20 mol%. However, the total amount of iron, nickel and cobalt is 100 mol% or less.

The alloy powder of this embodiment does not exclude the inclusion of other additive components other than magnetic metals (Fe, Ni, and Co). Copper (Cu) and/or boron (B) etc. are mentioned as such an additive component. However, in terms of maximizing the use of the effect of the magnetic metal, the less the content of the additive components other than the magnetic metal, the better. The content of components other than the magnetic metal may be 10% by mass or less, 5% by mass or less, 1% by mass or less, or 0% by mass. In addition, the alloy powder may contain impurities (unavoidable impurities) that are unavoidably mixed in the production steps. Examples of such unavoidable impurities include oxygen (O), carbon (C), chlorine (Cl), and basic components (Na, K, etc.). Unavoidable impurities may degrade the properties of the alloy powder, so it is preferable to suppress the amount thereof as much as possible. The amount of unavoidable impurities is preferably at most 5% by mass, more preferably at most 3% by mass, as long as it is oxygen (O) contained in the oxide film that is inevitably formed on the surface of the alloy powder. On the other hand, carbon (C), chlorine (Cl), and basic components (Na, K, etc.) are preferably at most 1% by mass, more preferably at most 0.5% by mass, further preferably at most 0.1% by mass. The alloy powder may have a composition containing a magnetic metal, and the balance being made up of unavoidable impurities.

The method for producing alloy powder in this embodiment includes at least a preparation step, a crystallization step, and a recovery step. In addition, a disintegration step and a high-temperature heat treatment step may be included after the recycling step or in the middle of the recycling step, or an insulating coating step may be provided after the recycling step. An example of the manufacturing process in the manufacturing method of this embodiment is schematically shown in FIG. 1. In FIG. 1 , disintegration treatment, high-temperature heat treatment, and insulating coating treatment are shown, but these treatments are not essential as long as they are provided as needed. Also, when performing disintegration treatment, high-temperature heat treatment, and/or insulating coating treatment, the order of performing these treatments is not particularly limited. If it is absolutely necessary, it is preferable to carry out disintegration treatment after high-temperature heat treatment. The reason is that the interconnection (bond) of the alloy grains strengthened by the high-temperature heat treatment can be reduced or eliminated. Also, it is preferable to perform disintegration treatment before insulating coating. The reason for this is that the insulating coating can be uniformly applied to the entire surface of each of the alloy particles whose bonding has been reduced or eliminated. On the other hand, if the alloy particles are connected together, an insulating coating cannot be formed on the connected part. Therefore, it is preferable to reduce or eliminate the connection as much as possible before the insulating coating treatment. The details of each step are described below.

＜Preparation steps＞ In the preparation step, a magnetic metal source, a nucleating agent, a complexing agent, a reducing agent, and a pH adjusting agent are prepared as starting materials. The magnetic metal source is the raw material of iron and nickel, and may also contain cobalt raw material as required. Moreover, an amine compound may be contained in a starting material. Each raw material is demonstrated below.

(a) Magnetic metal source Magnetic metal source is the raw material of magnetic metal, at least including water-soluble iron salt and water-soluble nickel salt. The raw material (iron source) of the iron component contained in the iron salt-based alloy powder is not particularly limited as long as it is an easily water-soluble iron salt. Examples of iron salts include ferric chloride, ferric sulfate, ferric nitrate, or mixtures thereof containing divalent and/or ferric ions. The water-soluble iron salt is preferably at least one selected from the group consisting of ferrous chloride (FeCl ₂ ), ferrous sulfate (FeSO ₄ ), and ferrous nitrate (Fe(NO ₃ ) ₂ ). The raw material (nickel source) of the nickel component contained in the nickel salt-based alloy powder is not particularly limited as long as it is an easily water-soluble nickel salt. As for the water-soluble nickel salt, at least one selected from the group consisting of nickel chloride (NiCl ₂ ), nickel sulfate (NiSO ₄ ), and nickel nitrate (Ni(NO ₃ ) ₂ ) is suitable. Particularly suitable is at least one selected from the group consisting of nickel chloride (NiCl ₂ ) and nickel sulfate (NiSO ₄ ).

If necessary, the magnetic metal may further include cobalt (Co), and the magnetic metal source may further include a water-soluble cobalt salt. Thereby, iron-nickel-cobalt alloy powder can be produced. Iron-nickel-cobalt alloy powder in which part of iron or nickel is substituted with cobalt has a particularly high saturation magnetic flux density.

Water-soluble cobalt salt has the effect of promoting the reduction reaction (reduction promotion effect) during the crystallization of alloy powder, especially when the content ratio of iron (Fe) in the magnetic metal is greater than 60 mol%. The facilitation becomes more pronounced. Furthermore, the water-soluble cobalt salt also has the effect of making the alloy powder into spherical particles with a smooth surface (spheroidization promoting effect). Therefore, in the magnetic metal source, if the content ratio of the water-soluble iron salt is 60 mol% to 85 mol%, the content ratio of the water-soluble cobalt salt is 10 mol% to 30 mol%. , even if the amount of hydrazine used as a reducing agent is very small, spherical iron-nickel-cobalt alloy powder with a very large saturation magnetic flux density (for example, 2 T (Tesla) or more) and a smooth surface can be obtained. Regarding the alloy powder, for example, the content ratio of iron is not less than 60 mol % and not more than 85 mol %, and the content ratio of cobalt is not less than 10 mol % and not more than 30 mol %.

The water-soluble cobalt salt is not particularly limited as long as it is an easily water-soluble cobalt salt. As for the water-soluble cobalt salt, at least one selected from the group consisting of cobalt chloride (CoCl ₂ ), cobalt sulfate (CoSO ₄ ), and cobalt nitrate (Co(NO ₃ ) ₂ ) is suitable, and particularly suitable is At least one selected from the group consisting of cobalt chloride (CoCl ₂ ) and cobalt sulfate (CoSO ₄ ).

(b) Nucleating agent The nucleating agent is a water-soluble salt of a metal that is on the noble metal side compared to nickel. The nucleating agent (a water-soluble salt of a metal that is more precious than nickel) has the following effect, that is, it is preferentially reduced in the reaction solution in the subsequent crystallization step to generate an initial nucleus, which promotes the precipitation of the crystallization powder . Here, the metal on the noble metal side relative to nickel refers to a metal that has a higher potential than nickel in the standard potential series in an aqueous solution. Also, a metal that is closer to the noble metal side than nickel can also be referred to as a metal that has a smaller ionization tendency than nickel. Examples of such metals include tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), copper (Cu), silver (Ag), palladium (Pd), iridium (Ir), platinum ( Pt), and gold (Au).

By using a water-soluble salt of a metal that is more precious than nickel as a nucleating agent, the formation of crystallization powder in the reaction solution can be controlled in the subsequent crystallization step. For example, if the amount of nucleating agent added is increased, fine crystallized powder can be obtained. That is, in the crystallization step, the ions or aluminum ions of the magnetic metal contained in the reaction solution are reduced and precipitated to form a crystallized powder. Among magnetic metals, nickel has the property of being more noble metal than iron or cobalt, and has a smaller ionization tendency. Therefore, if the water-soluble salt (nucleating agent) of the metal on the noble metal side relative to nickel is contained in the reaction solution, the metal on the noble metal side relative to nickel will be reduced and precipitated before all the magnetic metals. The precipitated metal that is biased toward the noble metal side than nickel acts as an initial nucleus, and the initial nucleus undergoes grain growth to form a crystallization powder composed of magnetic metals. Therefore, it can be determined by the amount of nucleating agent added to determine the initial nucleus number. Control the particle size of crystallization powder.

The nucleating agent is not particularly limited as long as it is a water-soluble salt of a metal that is closer to the noble metal than nickel. However, the nucleating agent is preferably at least one selected from the group consisting of copper salts, palladium salts, and platinum salts. Copper (Cu), palladium (Pd), and platinum (Pt) are particularly strong in nature toward the noble metal side, and have a low ionization tendency. Therefore, the effect as a nucleating agent is excellent. Although it does not specifically limit as a water-soluble copper salt, Copper sulfate is mentioned. Moreover, it does not specifically limit as a water-soluble palladium salt, Palladium (II) chloride sodium, palladium (II) chloride ammonium, palladium (II) nitrate, palladium (II) sulfate etc. are mentioned. As nucleating agents, palladium salts are especially suitable. If palladium salt is used, the particle size of the crystallized powder (alloy powder) can be controlled to be finer.

What is necessary is just to prepare the compounding quantity of a nucleating agent so that the particle diameter of the alloy powder finally obtained may become a desired value. For example, the blending amount of the nucleating agent may be not less than 0.001 mol ppm and not more than 5.0 mol ppm, or may be not less than 0.005 mol ppm and not more than 2.0 mol ppm relative to the total amount of the magnetic metal. By setting the blending amount of the nucleating agent within this range, an alloy powder having an average particle diameter of 0.2 μm or more and 0.6 μm or less can be obtained. However, the compounding amount of a nucleating agent is not limited to the said range. For example, when producing a fine alloy powder with an average particle diameter of less than 0.2 μm, it is sufficient to set the compounding amount of the nucleating agent to exceed 5.0 mole ppm.

(c) Complexing Agent The complexing agent is at least one selected from the group consisting of hydroxycarboxylic acids, salts of hydroxycarboxylic acids, and derivatives of hydroxycarboxylic acids. The complexing agent (hydroxycarboxylic acid, etc.) has the effect of achieving homogenization of the reaction in the subsequent crystallization step. That is, the magnetic metal component dissolves in the reaction solution in the form of magnetic metal ions (Fe ²⁺ , Ni ²⁺ , etc.), but the reaction solution is made strongly alkaline by the pH regulator (NaOH, etc.), so the reaction solution contains The amount of dissolved magnetic metal ions is very small. However, if a complexing agent is present, a large amount of magnetic metal components can be dissolved in the form of complex ions (Fe complex ions, Ni complex ions, etc.). The reduction reaction speed is increased by the existence of such an ion, and the local segregation of the magnetic metal component is suppressed, so that the uniformity of the reaction system can be realized. In addition, the complexing agent has the effect of changing the complexation stability balance of the plurality of magnetic metal ions in the reaction solution. Therefore, if a complexing agent exists, the reduction reaction of the magnetic metal changes, and the balance between the nucleation rate and the grain growth rate changes. By using the specific complexing agent (hydroxycarboxylic acid, etc.) in this embodiment, not only the above-mentioned effects are additionally exerted, but also the reaction develops in a better direction. As a result, the powder properties (particle size) of the obtained alloy powder diameter, particle size distribution, sphericity, particle surface properties) are improved. In addition, the alloy powder with improved powder properties has excellent filling properties and is suitable as a raw material for powder cores. From this aspect, it can be said that the complexing agent (hydroxycarboxylic acid, etc.) of the present embodiment functions as a reduction reaction accelerator, a spheroidization accelerator, and a surface smoothing agent. Suitable complexing agents comprise at least one hydroxycarboxylic acid selected from tartaric acid ((CH(OH)COOH) ₂ ) and citric acid (C(OH)(CH ₂ COOH) ₂ COOH).

Relative to the total amount of magnetic metals, the blending amount of complexing agent is preferably from 5 mol % to 100 mol %, more preferably from 10 mol % to 75 mol %, still more preferably 15 mol % More than 50 mole% below. If the blending amount is more than 5 mol%, it can fully exert its functions as a reduction reaction accelerator, a spheroidization accelerator, and a surface smoothing agent. Therefore, the powder characteristics of the alloy powder (particle size, particle size distribution, spherical shape, particle surface properties) become more excellent. Also, if the compounding amount is 100 mol% or less, there will not be a large difference in the degree of expression of the function as a complexing agent, and the usage amount of the complexing agent can be suppressed, thereby reducing the production cost.

(d) Reducing agent The reducing agent is hydrazine (N ₂ H ₄ , molecular weight: 32.05). The reducing agent (hydrazine) has the function of reducing magnetic metal ions and aluminum ions in the reaction solution in the subsequent crystallization step. Hydrazine not only has strong reducing power, but also has the advantage of not generating by-products accompanying the reduction reaction in the reaction solution. Also, it is easy to obtain high-purity hydrazine with less impurities.

Regarding hydrazine, in addition to anhydrous hydrazine, hydrazine hydrate (N ₂ H ₄ ·H ₂ O, molecular weight: 50.06) is known as a hydrazine hydrate. Either can be used. As hydrazine hydrate, for example, commercially available industrial grade 60 mass % hydrazine hydrate can be used.

The blending amount of the reducing agent depends to a large extent on the composition of the iron (Fe)-nickel (Ni) alloy powder. The greater the content of the iron that is not easily reduced, the more it needs to be blended. Moreover, in addition to the composition of the alloy powder, it is also affected by the temperature of the reaction solution, or the blending amount of the complexing agent or the pH adjusting agent, and the like. For example, when the iron content in the iron-nickel alloy powder is 60 mol% or less, relative to the total amount of the magnetic metal, the blending amount of the reducing agent is preferably from 1.8 to 7.0 in terms of molar ratio, more preferably 2.0 to 6.0, and more preferably 2.5 to 5.0. If the iron content of the iron-nickel alloy powder is more than 60 mole % and less than 75 mole %, the amount of the reducing agent added is preferably 2.5 to 9.0 in terms of molar ratio relative to the total amount of magnetic metal. or less, more preferably not less than 3.5 and not more than 8.0. If the iron content of the iron-nickel alloy powder is more than 75 mole % and less than 95 mole %, the amount of reducing agent blended is preferably 3.5 to 10.0 in terms of molar ratio relative to the total amount of magnetic metal or less, more preferably not less than 4.5 and not more than 9.0. On the other hand, when producing iron-nickel-cobalt alloy powder, the addition of reducing agent can be greatly reduced compared with iron-nickel alloy powder by the effect of the above-mentioned water-soluble cobalt salt. Especially in the manufacture of alloy powders with a relatively large iron content, the effect of water-soluble cobalt salts is remarkable. For example, when producing alloy powder with a content ratio of 60 mol% to 85 mol% of iron and a content ratio of cobalt (Co) of 10 mol% to 30 mol%, relative to the magnetic metal The total amount, the blending amount of the reducing agent is preferably from 1.0 to 4.0, more preferably from 1.2 to 2.0, in terms of molar ratio.

In any case, if the blending amount is above the above lower limit, the magnetic metal ions and zirconium ions will be fully reduced, and crystallized powder (alloy powder) that is not mixed with unreduced substances such as iron hydroxide can be obtained . Moreover, since the usage-amount of a reducing agent (hydrazine) can be suppressed when a compounding quantity is below the said upper limit, reduction of manufacturing cost is aimed at.

(e) pH regulator The pH adjuster is an alkali metal hydroxide. The pH adjuster (alkali metal hydroxide) has the effect of intensifying the reduction reaction of hydrazine as a reducing agent. That is, the higher the pH of the reaction solution, the stronger the reducing power of hydrazine. Therefore, by using alkali metal hydroxide as a pH regulator, the reduction reaction of magnetic metal ions and aluminum ions in the reaction solution, and the subsequent precipitation of crystallization powder are promoted. The type of alkali metal hydroxide is not particularly limited. However, considering the ease of acquisition and price, the pH adjuster preferably contains at least one selected from sodium hydroxide (NaOH) and potassium hydroxide (KOH).

What is necessary is just to prepare so that the reducing power of a reducing agent (hydrazine) becomes high enough about the compounding quantity of a pH adjuster (alkali metal hydroxide). Specifically, the pH of the reaction liquid at the reaction temperature is preferably at least 9.5, more preferably at least 10, and still more preferably at least 10.5. Therefore, what is necessary is just to adjust the compounding quantity of the alkali metal hydroxide so that pH may fall in this range.

(f) Amine compound The starting material may further contain an amine compound as needed. The amine compound contains two or more primary amine groups (-NH ₂ ), one primary amine group (-NH ₂ ) and one or more secondary amine groups (-NH-), or two or more secondary amine groups in the molecule group (-NH-).

The amine compound has the effect of promoting the reduction reaction in the subsequent crystallization step. That is, the amine compound has the function as a complexing agent, and has the function of complexing the magnetic metal ions (Fe ²⁺ , Ni ²⁺ , etc.) . It is also believed that the presence of Zn ions in the reaction solution will promote the further reduction reaction.

Also, the amine compound has the effect of inhibiting the self-decomposition of hydrazine as a reducing agent. That is, when the crystallized powder composed of magnetic metal precipitates in the reaction liquid, nickel (Ni) in the magnetic metal acts as a catalyst, and as a result, hydrazine may be decomposed. This is called self-decomposition of hydrazine. This decomposition reaction is a reaction in which hydrazine (N ₂ H ₄ ) is decomposed into nitrogen (N ₂ ) and ammonia (NH ₃ ), as shown in the following formula (1). If such self-decomposition occurs, the function of hydrazine as a reducing agent will be impaired, which is not preferable.

3N ₂ H ₄ →N ₂ ↑＋4NH ₃・・・（1）

The self-decomposition of hydrazine can be suppressed by adding an amine compound to the blended solution in advance. Although the detailed mechanism is not clear, it is presumed that the reason is that the excessive contact between the hydrazine in the reaction solution and the crystallization powder is hindered. That is, the amine group contained in the amine compound molecule, especially the primary amine group (-NH ₂ ) or secondary amine group (-NH-), will be firmly adsorbed on the surface of the crystallization powder in the reaction solution. It is considered that the amine compound molecules cover the crystallization powder to protect it, thereby hindering the excessive contact between the hydrazine molecules and the crystallization powder, thereby inhibiting the self-decomposition of hydrazine. When the content ratio of nickel in the magnetic metal is large, the self-decomposition of hydrazine becomes remarkable, so especially in this case, the amine compound works effectively.

As the amine compound, at least one of alkylene amines and alkylene amine derivatives is suitable. In addition, regarding alkylene amines and/or alkylene amine derivatives, it is suitable to have at least the nitrogen atom of the amino group in the molecule, which is represented by the following (A) through a carbon chain having 2 carbon atoms. the structure.

By using such an alkylene amine or an alkylene amine derivative as an amine compound, the effect of suppressing the self-decomposition of hydrazine (reducing agent) can be exhibited more effectively. The reason for this is considered to be that such alkylene amine or alkylene amine derivatives can effectively inhibit the contact of hydrazine molecules with the crystallization powder due to the short carbon chain contained therein. On the other hand, when the nitrogen atoms of the amine group are bonded together through an excessively long carbon chain, even if the amine group is adsorbed on the crystallization powder, the freedom of movement of the carbon chain is relatively large. Therefore, it is speculated that the contact between the crystallization powder and the hydrazine molecules cannot be effectively prevented.

Specific examples of alkylene amines having the structure represented by the above (A) are selected from ethylenediamine (abbreviation: EDA) (H ₂ NC ₂ H ₄ NH ₂ ), diethylenetriamine (abbreviation: DETA) (H ₂ NC ₂ H ₄ NHC ₂ H ₄ NH ₂ ), triethylenetetramine (abbreviation: TETA) (H ₂ N(C ₂ H ₄ NH) ₂ C ₂ H ₄ NH ₂ ), tetraethylenetetramine Pentamine (abbreviation: TEPA) (H ₂ N(C ₂ H ₄ NH) ₃ C ₂ H ₄ NH ₂ ), pentaethylenehexamine (abbreviation: PEHA) (H ₂ N(C ₂ H ₄ NH) ₄ C ₂ H ₄ NH ₂ ), propylenediamine (alias: 1,2-diaminopropane, 1,2-propylenediamine) (abbreviation: PDA) (CH ₃ CH(NH ₂ )CH ₂ NH ₂ ) More than one of the groups formed. Also, specific examples of alkylene amine derivatives having the structure represented by the above (A) are selected from tris(2-aminoethyl)amine (abbreviation: TAEA) (N(C ₂ H ₄ NH ₂ ) ₃ ), N-(2-aminoethyl)ethanolamine (alias: 2-(2-aminoethylamino)ethanol) (abbreviation: AEEA) (H ₂ NC ₂ H ₄ NHC ₂ H ₄ OH), N -(2-aminoethyl)propanolamine (alias: 2-(2-aminoethylamino)propanol) (abbreviation: AEPA) (H ₂ NC ₂ H ₄ NHC ₃ H ₆ OH), L (or D, DL)-2,3-diaminopropionic acid (alias: 3-amino-L (or D, DL)-alanine) (abbreviation: DAPA) (H ₂ NCH ₂ CH(NH)COOH ), ethylenediamine-N,N'-diacetic acid (alias: N,N'-ethylene diglycine) (abbreviation: EDDA) (HOOCCH ₂ NHC ₂ H ₄ NHCH ₂ COOH), 1,2-cyclohexyl One or more of alkanediamine (alias: 1,2-diaminocyclohexane) (abbreviation: CHDA) (H ₂ NC ₆ H ₁₀ NH ₂ ). These alkylene amines or alkylene amine derivatives are water-soluble. Among them, ethylenediamine and diethylenetriamine are relatively strong in inhibiting the self-decomposition of hydrazine, easy to obtain, and low in price, so they are more preferred. good.

Ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), propanediamine Amine (PDA), tris(2-aminoethyl)amine (TAEA), N-(2-aminoethyl)ethanolamine (AEEA), N-(2-aminoethyl)propanolamine (AEPA) , and the structural formulas of L (or D, DL)-2,3-diaminopropionic acid (DAPA) are shown in (B) to (M) below.

The blending amount of the amine compound is preferably from 0.00 mol % to 5.00 mol %, more preferably from 0.01 mol % to 5.00 mol %, and still more preferably 0.03 mol %, relative to the total amount of magnetic metals. More than 5.00 mol% or less. The blending amount of the amine compound can also be 0.00 mol %, that is, no amine compound is blended. However, by setting the compounding amount to 0.01 mol % or more, the effect of suppressing the self-decomposition of hydrazine and the effect of promoting the reduction reaction by the amine compound can be sufficiently exerted. Moreover, the function as a complexing agent can be exhibited moderately by making a compounding quantity into 5.00 mol % or less. Therefore, the powder properties (particle size, particle size distribution, sphericity, and particle surface properties) of the alloy powder can be made more excellent. When the blending amount of the amine compound is increased and exceeds 5.00 mol %, the function as a complexing agent becomes too strong. There is concern about abnormal particle growth and deterioration of the powder properties of the alloy powder.

＜Crystalization step＞ In the crystallization step, a reaction liquid containing the prepared starting materials and water is prepared, and the crystallization powder containing the above-mentioned magnetic metal is crystallized by a reduction reaction in the reaction liquid. The preparation of the reaction solution and the crystallization of the crystallization powder will be described respectively below. Furthermore, in actual production, although the crystallization reaction is started at the same time as the preparation of the reaction liquid in most cases, the crystallization reaction may also start during the preparation of the reaction liquid, even if the possibility is very small. Furthermore, the crystallization reaction mentioned here refers to the reaction that occurs during the crystallization process. That is, although the reduction reaction by hydrazine (the following (6) formula etc.) is the main thing, the self-decomposition reaction of hydrazine (the above-mentioned (1) formula) etc. are also included. Therefore, the term crystallization reaction is used in a broader sense than reduction reaction.

In the crystallization step, at least any one of a plurality of solutions such as a metal salt raw material solution or a reducing agent solution is heated and then mixed to prepare a reaction solution, and the reaction solution is kept at a specified temperature while heating and stirring in the reaction tank. temperature, the crystallization reaction is carried out in this state. General-purpose methods can be used for heating, for example, a method of installing a reaction vessel (reaction container) in a water bath, or a method of using a reaction vessel with a steam jacket or a reaction vessel with a heater. For the reaction tank (reaction container) or the stirring blade used to stir the reaction liquid, from the viewpoint of not hindering the action of the nucleating agent, it is required that it is as difficult as possible to touch the surface when it comes into contact with the reaction liquid An inactive material that undergoes nucleation, and requires excellent strength or thermal conductivity. To meet these requirements, for example, metal containers (Teflon (registered trademark) coated stainless steel containers, etc.) obtained by coating with fluororesin (PTFE, PFA, etc.) or stirring blades (Teflon (registered trademark) ) coated stainless steel stirring blades, etc.).

(a) Preparation of reaction solution First, a magnetic metal source as a starting material, a nucleating agent, a complexing agent, a reducing agent, a pH regulator, and an amine compound as needed are dissolved in water and mixed as needed to prepare a reaction solution. As the water used in the preparation of the reaction liquid, in order to reduce the amount of impurities in the finally obtained alloy powder, it is preferable to use high-purity water. As high-purity water, pure water with a conductivity of 1 μS/cm or less, or ultrapure water with a conductivity of 0.06 μS/cm or less can be used, and among them, it is preferable to use cheap and easily available pure water.

When the starting materials are solids such as iron salts, nickel salts, cobalt salts, and alkali metal hydroxides, it is preferable to preliminarily mix them with water and dissolve them to form an aqueous solution. The mixing of the starting material and water may be performed by known methods such as stirring and mixing. The order of mixing the starting materials or the aqueous solution is not particularly limited as long as the uniformity of the reaction solution is not impaired. However, from the viewpoint of ensuring the uniformity of the reaction solution, it is preferable to separately prepare aqueous solutions containing each starting material in advance, and to mix the prepared aqueous solutions, especially according to the first aspect or the first described below. 2 to prepare the reaction solution.

In the first aspect, when preparing the reaction solution in the crystallization step, a metal salt raw material solution prepared by dissolving the magnetic metal source, a nucleating agent, and a complexing agent in water, and a reducing agent dissolved in water are respectively prepared. The reducing agent solution and the pH adjusting solution obtained by dissolving the pH adjusting agent in water, the metal salt raw material solution and the pH adjusting solution are mixed to form a mixed solution, and the obtained mixed solution is mixed with the reducing agent solution. A process chart showing an example of the preparation of the reaction solution and the production of the alloy powder in the first aspect is shown in FIGS. 2 and 3 .

In the first aspect, the metal salt raw material solution, the reducing agent solution and the pH adjustment solution are prepared separately. Metal salt raw material solution is to dissolve magnetic metal source (water-soluble iron salt, water-soluble nickel salt, etc.), nucleating agent (water-soluble salt of metal that is more precious than nickel), and complexing agent (hydroxycarboxylic acid, etc.) in water while preparing. The reducing agent solution was prepared by dissolving the reducing agent (hydrazine) in water. The pH adjusting solution is prepared by dissolving a pH adjusting agent (alkali metal hydroxide) in water. Next, the metal salt raw material solution and the pH adjustment solution are mixed to prepare a mixed solution. At this time, the salt of the magnetic metal (water-soluble iron salt, water-soluble nickel salt, etc.) contained in the metal salt raw material solution reacts with the alkali metal hydroxide contained in the pH adjuster to form a hydroxide of the magnetic metal . The hydroxide is iron hydroxide (Fe(OH) ₂ ), nickel hydroxide (Ni(OH) ₂ ), cobalt hydroxide (Co(OH) ₂ ), iron nickel hydroxide ((Fe, Ni)( OH) ₂ ), iron-nickel-cobalt hydroxide ((Fe, Ni, Co)(OH) ₂ ), etc. Then, the reducing agent solution is mixed with the obtained mixed solution to prepare a reaction liquid.

As a specific preparation sequence of the reaction solution in the first aspect, it is preferable to sequentially add the pH adjustment solution and the reducing agent solution to the metal salt raw material solution and mix them. In the first aspect using the metal salt raw material solution, the reducing agent solution, and the pH adjustment solution, the liquid amount (volume) of the metal salt raw material solution is the largest. Therefore, the reason is that, compared to adding the metal salt raw material solution to other solutions, sequentially adding other solutions to the metal salt raw material solution with a larger liquid volume and mixing can further realize a uniform mixed state, and can be used in the reaction solution. uniform reduction reaction.

When blending an amine compound, what is necessary is just to add an amine compound to at least one of a metal salt raw material solution, a reducing agent solution, and a pH adjuster solution. Moreover, after mixing all these solutions, you may add an amine compound. FIG. 2 shows a state in which an amine compound is added to at least one of a metal salt raw material solution, a reducing agent solution, and a pH adjustment solution. FIG. 3 shows a state in which an amine compound is added to a reaction liquid obtained by mixing all the metal salt raw material solution, the reducing agent solution, and the pH adjustment solution.

In the first aspect, a reducing agent solution is mixed with a mixed solution of a metal salt raw material solution and a pH adjuster to prepare a reaction solution, and the reduction reaction proceeds from the point of addition of the reducing agent solution. When mixing the reducing agent solution, the concentration of the reducing agent (hydrazine) increases rapidly locally in the small area where the reducing agent is added. Also, the mixed solution contains a pH adjuster (alkali metal hydroxide), and the pH of the mixed solution (reaction solution) is still high at the initial stage of mixing the reducing agent solution into the mixed solution. As mentioned above, the higher the pH, the stronger the reducing power of the reducing agent (hydrazine). Therefore, at the initial stage of mixing the reducing agent solution, the concentration and pH of the reducing agent become locally high, and the reduction reaction of nucleation by the nucleating agent and crystallized powder occurs rapidly. On the other hand, as the reducing agent solution is added, the pH of the mixed solution (reaction liquid) gradually decreases. Therefore, in the final stage of the mixed reducing agent solution, the reducing power of the reducing agent is not as strong as that in the initial stage, and the nucleation and reduction reactions proceed slowly. Therefore, the reducing power of the reducing agent differs between the initial stage and the final stage of mixing the reducing solution.

If the difference in reducing power between the initial stage and the final stage is large, the uniformity of the nucleation reaction and reduction reaction will decrease, and the unevenness of the powder properties (particle size, surface smoothness, etc.) of the obtained crystallized powder will become larger. Yu. Therefore, it is desirable to reduce the difference in reducing power as much as possible. Thus, it is desirable to mix the reducing agent solution as quickly as possible. The time required to mix the reducing agent solution into the mixed solution of the metal salt raw material solution and the pH adjuster (mixing time) is preferably 180 seconds or less, more preferably 120 seconds or less, further preferably 60 seconds or less. On the other hand, it may be difficult to make the mixing time too short due to limitations of manufacturing equipment. The mixing time may be longer than 1 second, longer than 3 seconds, or longer than 5 seconds.

Furthermore, when mixing the pH regulator solution in the metal salt raw material solution, similarly if the mixing time is longer, the characteristics of the formed magnetic metal hydroxide will be uneven, which may lead to uneven powder characteristics of the crystallization powder. all. Although this effect is not as great as that of mixing the reducing agent solution, the shorter the mixing time, the better. The time required for mixing the pH adjuster (mixing time) is preferably 180 seconds or less, more preferably 120 seconds or less, further preferably 80 seconds or less. Moreover, mixing time may be 1 second or more, 3 seconds or more, or 5 seconds or more.

It is also effective in suppressing uneven powder properties of the crystallized powder to perform agitation mixing in which the solutions are mixed while stirring the reducing agent solution or the pH adjuster solution. Stirring can suppress the rapid increase of the concentration of the components in the solution, so that the characteristic unevenness of the crystallized powder can be suppressed. Stirring and mixing may be performed using a stirring device such as a stirring blade.

In the second aspect, when the reaction solution is prepared in the crystallization step, the metal salt raw material solution, which is made by dissolving the magnetic metal source, the nucleating agent, and the complexing agent in water, and the reducing agent and the pH adjusting agent are prepared separately. A reducing agent solution dissolved in water is obtained by mixing the metal salt raw material solution and the reducing agent solution. A process chart showing an example of the preparation of the reaction solution and the production of the alloy powder in the second aspect is shown in Fig. 4 and Fig. 5 .

In the second aspect, two kinds of solutions, the metal salt raw material solution and the reducing agent solution, are separately prepared. The metal salt raw material solution is to dissolve the magnetic metal source (water-soluble iron salt, water-soluble nickel salt, etc.), nucleating agent (water-soluble salt of a metal that is more precious than nickel), and complexing agent (hydroxycarboxylic acid, etc.) prepared in water. The reducing agent solution was prepared by dissolving a reducing agent (hydrazine) and a pH adjuster (alkali metal hydroxide) in water. Next, the metal source raw material solution and the reducing agent solution are mixed to prepare a reaction solution. The second aspect differs from the first aspect in that the reducing agent solution contains a pH adjuster.

As the specific preparation sequence of the reaction solution in the second aspect, the following two methods can be used: adding the reducing agent solution to the metal salt raw material solution and mixing; or vice versa, adding the metal salt raw material solution to the reducing agent solution and mixing . Unlike the first aspect, the liquid amount (volume) of the reducing agent solution containing both the reducing agent and the pH adjuster (alkali metal hydroxide) is on the same level as the liquid amount (volume) of the metal salt raw material solution. Therefore, by adding either one to the other and mixing, basically a uniform mixed state can be realized, and a uniform reduction reaction can be performed in the reaction liquid.

However, under crystallization conditions in which the mixing ratio of the reducing agent or pH adjuster (alkali metal hydroxide) to the metal salt raw material is large, it is preferable to add and mix the metal salt raw material solution to the reducing agent solution. This is because, from the viewpoint of ensuring productivity in the crystallization step, it is desirable to maintain the concentration of the metal salt raw material in the reaction solution at a predetermined level or higher (30 to 40 g/L in terms of metal components). That is, under the above-mentioned crystallization conditions, the liquid amount (volume) of the reducing agent solution is much larger than the liquid amount (volume) of the metal salt raw material solution. Therefore, adding and mixing a metal salt raw material solution with a small liquid amount (volume) to a reducing agent solution with a large liquid amount (volume) can achieve a uniform mixed state, and the reduction reaction can be uniformly carried out in the reaction solution.

In the second aspect, for the same reason as in the first aspect, the time required for mixing the reducing agent solution into the metal salt solution (mixing time) is preferably 180 seconds or less, more preferably 120 seconds or less, Furthermore, it is preferably 60 seconds or less. In addition, the mixing time may be longer than 1 second, longer than 3 seconds, or longer than 5 seconds. Moreover, it is also effective to perform stirring and mixing when mixing the reducing agent solution.

In the third aspect, in the crystallization step of the first aspect or the second aspect, an additional raw material liquid is further added to the reaction liquid and mixed before the reduction reaction is completed. Thereby, the surface of the crystallized powder is enriched with nickel or cobalt. Here, the additional raw material solution is obtained by dissolving at least one of the above-mentioned water-soluble nickel salt and water-soluble cobalt salt in water. A process chart showing an example of alloy powder production in the third aspect is shown in FIG. 6 .

In the third aspect, in addition to the solution used in the preparation of the reaction solution of the first aspect or the second aspect, an additional raw material solution is also prepared. This additional raw material liquid is prepared by dissolving at least one of a water-soluble nickel salt and a water-soluble cobalt salt in water. Addition of the additional raw material liquid to the reaction liquid may be performed by methods such as one-time addition, batch addition, and/or dropwise addition. The addition is preferably performed at a point before the completion of the reduction reaction, but not necessarily. When the reduction reaction is completely completed, the crystallized particles start to form aggregates with each other. If an additional raw material solution is added at this point in time, and the metal component is precipitated by a reduction reaction, the bond between the particles contained in the aggregate may be strengthened.

Also, according to the third aspect, there is an advantage that the amount of reducing agent used can be reduced compared with the first aspect or the second aspect. The reason for this is that iron ions (or iron hydroxide) are less easily reduced than nickel ions (or nickel hydroxide) or cobalt ions (or cobalt hydroxide). If an additional raw material solution containing nickel or cobalt is added to the reaction solution, the reduction reaction of iron ions (or iron hydroxide) that is not easily reduced can be promoted in the final stage of crystallization.

The amount of magnetic metals (Ni, Co) in the additional raw material solution may be set according to the degree to which the surface of the crystallized powder is enriched in nickel or cobalt. However, considering the composition uniformity of the entire particle, it is preferably 5 mol% to 50 mol% relative to the total amount of magnetic metals (Ni, Co) other than iron in the alloy powder. If the particle surface is rich in nickel or cobalt components, the iron components that tend to form porous oxide films decrease. In this way, a dense oxide film is formed, and the amount of oxidation on the surface of the particles is suppressed. Therefore, it not only becomes more stable in the atmosphere, but also improves magnetic properties such as saturation magnetic flux density.

(b) Crystallization of crystallization powder When a reaction liquid is prepared, a reduction reaction occurs in the reaction liquid. That is, in the coexistence of a pH regulator (alkali metal hydroxide) and a nucleating agent (a salt of a metal that is more precious than nickel), the reducing agent (hydrazine) is used to reduce the ions or zirconium ions of the magnetic metal source, thereby A crystallized powder containing magnetic metal is formed.

The reduction reaction in the crystallization step will be described using the reaction formula. The reduction reaction of iron (Fe), nickel (Ni) and cobalt (Co) is a two-electron reaction as shown in the following formulas (2) to (4). On the other hand, the reaction of hydrazine (N ₂ H ₄ ) as a reducing agent is a four-electron reaction as shown in the following formula (5).

Fe ²⁺ +2e ^- →Fe↓ (two-electron reaction)・・・(2) Ni ²⁺ +2e- ^→ Ni↓ (two-electron reaction)・・・(3) Co ²⁺ +2e- ^→ Co↓ (two-electron reaction )・・・(4) N ₂ H ₄ →N ₂ ↑＋4H ⁺ ＋4e ^- (four-electron reaction)・・・(5)

When using magnetic metal chlorides (FeCl ₂ , NiCl ₂ , CoCl ₂ ) as the magnetic metal source and sodium hydroxide (NaOH) as the pH regulator, as shown in the following formula (6), first, the magnetic metal Chlorides are neutralized with sodium hydroxide to produce hydroxides ((Fe, Ni, Co)(OH) ₂ , etc.). Then, the hydroxide ((Fe, Ni, Co)(OH) ₂ , etc.) is reduced by the action of the reducing agent (hydrazine) to become crystallized powder. In order to reduce 1 mole of magnetic metal (Fe, Ni, Co), 0.5 mole of reducing agent (hydrazine) is required. Also, observing the above formula (5), it can be seen that the higher the basicity (pH), the higher the reducing power of hydrazine. Therefore, sodium hydroxide used as a pH adjuster also has the effect of promoting the reduction reaction initiated by hydrazine.

(Fe,Ni,Co)Cl ₂ ＋1/2N ₂ H ₄ ＋2NaOH →(Fe,Ni,Co)(OH) ₂ ↓＋1/2N ₂ H ₄ ＋2NaCl→(Fe,Ni,Co)↓＋1/2N ₂ ↑ ＋2NaCl＋2H ₂ O ・・・（6）

In the reduction reaction of the above formula (6), the reduction of the respective element ions (or hydroxides) of the magnetic metals (Fe, Ni, Co) proceeds simultaneously to some extent by co-reduction. Here, the so-called co-reduction refers to a phenomenon in which other reduction reactions occur jointly when a reduction reaction of a certain element occurs. However, as mentioned above, iron ions (or iron hydroxide) are less easily reduced than nickel ions (or nickel hydroxide) or cobalt ions (or cobalt hydroxide). Therefore, in the final stage of the crystallization reaction, nickel ions (or nickel hydroxide) or cobalt ions (or cobalt hydroxide) in the reaction solution are consumed due to the reduction reaction and disappear, while iron ions (or iron hydroxide) tend to remain. This tendency is particularly remarkable when the iron content ratio is relatively high (for example, the iron content of the alloy powder exceeds 60 mol%). If this phenomenon occurs, it will not only take a long time until the crystallization reaction (reduction reaction) is completed, but also easily form a gradient structure with uneven composition in the particles. If a gradient structure is formed, the obtained alloy powder has a composition rich in nickel or cobalt in the center of the particle, and a composition rich in iron as it gets closer to the surface of the particle.

On the other hand, in the above-mentioned third aspect, an additional raw material liquid is added to the reaction liquid during the crystallization reaction, and the reduction reaction of iron ions (or iron hydroxide) which is not easily reduced is promoted in the final stage of crystallization. Therefore, it is possible to improve the prolonged crystallization reaction (reduction reaction) or the non-uniformity of the composition in the obtained alloy powder particles especially when the iron content ratio is large.

The temperature of the reaction solution (reaction initiation temperature) at the start of crystallization of the crystallization powder is preferably from 40°C to 90°C, more preferably from 50°C to 80°C, further preferably from 60°C to 70°C. Here, the reaction liquid at the start of crystallization refers to the reaction liquid containing the starting material and water immediately after preparation. Also, the temperature of the reaction liquid held during the crystallization after the start of the crystallization (reaction holding temperature) is preferably from 60°C to 99°C, more preferably from 70°C to 95°C, still more preferably from 80°C Below 90°C. In order to adjust the reaction initiation temperature within an appropriate range, it is preferable to heat at least any one of a plurality of solutions such as a metal salt raw material solution or a reducing agent solution for preparing the reaction solution in advance. In order to keep the reaction temperature within an appropriate range, it is desirable to continue heating the reaction liquid after preparing the reaction liquid.

From the standpoint of making nucleation more uniform and obtaining a crystallized powder with a sharp particle size distribution, if possible, it is preferable to heat one of a plurality of solutions such as a metal salt raw material solution or a reducing agent solution in advance ( For example, heating to 70°C), adding and mixing the other solution without preheating (for example, maintaining at 25°C) to prepare a reaction solution at a predetermined temperature (for example, 55°C). In contrast, if both of the two solutions (for example, the metal salt raw material solution and the reducing agent solution) are heated in advance (for example, to 70° C.), uneven nucleation tends to occur. That is, when two kinds of solutions are added and mixed, heat generated by mixing of the solutions will occur. Therefore, the solution (reaction liquid) obtained by adding and mixing becomes locally high temperature (for example, about 78° C.) at the beginning of mixing, and nucleation occurs instantaneously. In a state where the two solutions are added and mixed simultaneously with nucleation, this state tends to cause inhomogeneity of nucleation.

Although it is conceivable to improve the uniformity of nucleation by making the addition time of the two solutions extremely short, or vigorously stirring, it is difficult to say that this method is a preferable aspect. If it is the above-mentioned method, that is, only one solution is preheated (for example, heated to 70°C) and then added and mixed to prepare a reaction solution, the solution (reaction solution) obtained by adding and mixing is maintained at a low temperature (e.g. 55°C), it will not locally become high temperature. The time point of nucleation is delayed, so nucleation proceeds after the two solutions are fully mixed. Thus, nucleation occurs easily and uniformly. A more preferable example has been described above, and it does not exclude the case where all of the plurality of solutions such as the metal salt raw material solution or the reducing agent solution are heated in advance. What is necessary is just to set the heating of a solution and its temperature so that a reaction initiation temperature and a reaction maintenance temperature may fall in the said range.

If the reaction initiation temperature is too low, although the nucleation is further homogenized, the progress of the reduction reaction becomes slower, and the heating time required to raise the temperature to the reaction holding temperature that can promote the reduction reaction becomes longer. Similarly, if the reaction temperature is too low, the reduction reaction will be slowed down, and the heating time required for crystallization will be longer. In any case, the cycle time required for the crystallization step becomes longer, and productivity decreases. Furthermore, since hydrazine undergoes self-decomposition, a large amount of hydrazine is required, resulting in an increase in production cost. If the reaction initiation temperature or reaction maintenance temperature is higher, the reduction reaction will be promoted, the cycle time required for the crystallization step will be shortened, and the crystallization powder obtained will tend to be highly crystallized. However, at the same time, the self-decomposition speed of hydrazine becomes larger. Therefore, if the reaction initiation temperature or the reaction maintenance temperature is too high, not only nucleation inhomogeneity will occur, but also excessive high degree of crystallization will lead to poor smoothness of the particle surface, and there is a possibility that the unevenness of the surface may become large. Moreover, if the crystallization is not completed at an appropriate time point, hydrazine may be preferentially consumed due to self-decomposition by the reduction reaction. Therefore, a large amount of hydrazine is required, which may lead to an increase in production cost. By setting the reaction initiation temperature or the reaction maintenance temperature within the above-mentioned appropriate range, high-performance alloy powder can be manufactured at low cost while maintaining high productivity.

＜Recycling procedure＞ In the recovery step, crystallization powder is recovered from the reaction liquid obtained in the crystallization step. The recovery of the crystallized powder may be performed by a known method. For example, a method of solid-liquid separation of the crystallized powder from the reaction liquid using a separation device such as a Denver filter, a filter press, a centrifuge, or a decanter is exemplified. In addition, the crystallized powder may be washed during solid-liquid separation or after solid-liquid separation. Cleaning can only be performed with a cleaning solution. Just use high-purity pure water with a conductivity of 1 μS/cm or less as the cleaning solution. The crystallized powder after washing can be dried. Drying treatment only needs to use general drying equipment such as air dryer, hot air dryer, non-reactive gas environment dryer, reducing gas environment dryer, or vacuum dryer, and the temperature is above 40°C and below 150°C, preferably above 50°C It can be carried out at a temperature below 120°C. However, from the standpoint of preventing the magnetic properties from deteriorating due to excessive oxidation of the crystallized powder during the drying process, using an inert gas environment dryer, a reducing gas environment dryer, or a vacuum dryer is better than using an air dryer or It is better to use an atmospheric hot air dryer.

Furthermore, the surface of the crystallization powder dried in the airtight container of the non-reactive gas environment dryer, the reducing gas environment dryer, or the vacuum dryer is not excessively oxidized. Therefore, when it is taken out from the dryer immediately after drying to the atmosphere, the surface of the particles is rapidly oxidized, and the crystallized powder may burn due to heat generated by the oxidation reaction. This phenomenon is especially likely to occur in fine crystallized powder (eg, particle size below 0.1 μm). Therefore, it is preferable to carry out slow oxidation treatment, that is, form a thinner oxide film in advance on the particle surface of the crystallized powder whose particle surface is not substantially oxidized after drying to stabilize it. As the sequence of specific slow oxidation treatment, the following method is considered: the temperature of the crystallization powder that has been heated and dried in the airtight container of the inert gas atmosphere dryer, the reducing gas atmosphere dryer, or the vacuum dryer is reduced to After room temperature to about 40°C, supply a gas with a low oxygen concentration (such as nitrogen or argon containing 0.1 to 2 vol% oxygen) into the airtight container to slowly oxidize the particle surface of the crystallization powder little by little. Form a thinner oxide film. The crystallized powder that has been subjected to slow oxidation treatment is not easily oxidized and is stable, so even if it is placed in the atmosphere, there is no risk of heat generation or combustion.

＜High temperature heat treatment step＞ A high-temperature heat treatment step of performing high-temperature heat treatment on the crystallization powder may also be provided after the recovery step or during the recovery step. In the case of performing high-temperature heat treatment after the recovery step, it is only necessary to perform high-temperature heat treatment after drying treatment. In addition, when high-temperature heat treatment is performed in the middle of the recovery step, high-temperature heat treatment may be performed instead of drying treatment. The high-temperature heat treatment may be performed at a temperature of more than 150°C and less than 400°C, preferably at least 200°C and less than 350°C, in an inert environment, a reducing environment, or a vacuum environment. By high-temperature heat treatment, it can promote the diffusion of Fe and Ni and other dissimilar elements in the iron (Fe)-nickel (Ni) alloy particles, thereby improving the composition uniformity in the particles, or preparing magnetic properties such as magnetism. Furthermore, the above-mentioned slow oxidation treatment may also be performed after the high-temperature heat treatment as required.

＜Splitting steps＞ The following disintegration steps can be set as needed, that is, disintegrate the crystallization powder recovered in the recovery step, or the crystallization powder before drying treatment during the recovery process. When the alloy particles constituting the crystallization powder are precipitated in the crystallization step, the alloy particles can contact each other and fuse to form aggregated particles. Therefore, the crystallization powder obtained through the crystallization step may contain coarse aggregated particles. As described above, coarse aggregated particles may cause eddy currents to flow therein to increase loss due to Joule heat, or hinder the filling properties of the powder. Aggregated particles can be disintegrated by providing a disintegration step after the recovery step or in the middle of the recovery step. The disintegration may be performed by dry disintegration such as spiral jet disintegration treatment, reverse jet mill disintegration treatment, wet disintegration such as high-pressure fluid collision disintegration treatment, or other common disintegration methods. For the crystallization powder recovered as dry powder in the recovery step, dry crushing can be directly applied. In addition, if the crystallized powder which is a dry powder after the recovery step is made into a slurry, wet disintegration can be applied to it. Furthermore, if it is the slurry-like crystallization powder before drying obtained during the recovery step, wet disintegration can be applied directly. These fragmentation methods use the collision energy of the particles to fragment the aggregated particles into pieces. The collision during the disintegration process also promotes smoothing of the surface, so this effect is also beneficial to improve the filling properties of the powder.

＜Insulation coating process＞ An insulating coating step may be provided after the recovery step as required. In the insulating coating step, the crystallization powder obtained through the recovery step is subjected to insulating coating treatment, and an insulating coating composed of a high-resistance metal oxide is formed on the particle surface of the crystallization powder, thereby improving the interparticle distance. The insulation. Similar to the loss increase caused by the eddy current in the coarse aggregated particles, the powder core obtained by compression molding the iron-nickel alloy powder has eddies flowing between the particles due to the contact of the alloy particles. There is a danger that the current will increase. By forming an insulating coating, it is possible to suppress generation of eddy current due to contact between alloy particles.

In the insulating coating process, the crystallized powder is dispersed in a mixed solvent containing water and an organic solvent, and then the metal alkoxide is added and mixed into the mixed solvent to prepare a slurry, and the obtained slurry is used Metal alkoxides are hydrolyzed and dehydrated to form an insulating coating on the particle surface of the crystallization powder. Then, the solid-liquid separation of the bulk crystallization powder formed with the insulating coating is carried out from the slurry, and the separated crystallization powder The powder is dried, and the crystallized powder formed with an insulating coating composed of a high-resistance metal oxide is recovered. The separated and dried crystallized powder may also be subjected to heat treatment if necessary. Regarding the hydrolysis reaction of metal alkoxides in a mixed solvent containing water and organic solvents, if they are kept as they are, they will only proceed very slowly. Therefore, a small amount of hydrolysis catalysts such as acids or alkalis (alkali) are generally added to promote the reaction. . It is also preferable to add an alkali catalyst (alkali catalyst) in this embodiment.

As the high _- resistance _{metal oxide} , _{preferably at} least More than one kind is used as the main component. In particular, silicon dioxide (SiO ₂ ) is particularly preferable because it is inexpensive and has excellent insulating properties.

In order to obtain such a metal oxide, as the metal alkoxide used in the slurry in the insulating coating process, an alkoxide that can finally form a metal oxide through hydrolysis and dehydration polycondensation is selected. Specifically, it is preferred to be selected from the group consisting of silane oxides (alkyl silicates), aluminum alkoxides (alkyl aluminates), zirconium alkoxides (alkyl zirconates), and titanium alkoxides. (Alkyl titanate) is at least one kind as the main component, and among them, one having silane oxide (alkyl silicate) as the main component is particularly preferable. Furthermore, if necessary, when the metal alkoxide is hydrolyzed and dehydrated and polycondensed to form an insulating coating, components (such as borax oxides, etc.) that will be absorbed into the insulating coating by hydrolysis, etc., may be added to the Among the above-mentioned metal alkoxides.

The surface of the alloy powder subjected to insulating coating treatment is covered with a high-resistance metal oxide which is an inorganic substance. Organic functional groups can also be introduced into the surface of the inorganic substance as needed. Specifically, for example, a small amount of silicon-based, titanium-based, zirconium-based, and aluminum-based coupling agents are added to the metal alkoxide used in the insulating coating process, and the metal alkoxide is hydrolyzed and dehydrated during polycondensation. A method for taking an organic functional group into a metal oxide. In addition, as another method, the method of surface-treating the alloy powder subjected to insulation coating treatment with the above-mentioned coupling agent and modifying the surface of the metal oxide with an organic functional group can also be mentioned. Regardless of the method, the introduction of an organic functional group improves the affinity with the resin. Therefore, when the insulating-coated alloy powder is mixed with a resin binder and molded, it can be expected to improve the molded product. of strength.

As specific examples of silane oxides (alkyl silicates), for example, tetramethoxysilane (alias: tetramethyl orthosilicate, silicon tetramethoxide) (abbreviation: TMOS) (Si(OCH ₃ ) ₄ ), tetraethoxysilane (alias: tetraethyl orthosilicate, silicon tetraethoxide) (abbreviation: TEOS) (Si(OC ₂ H ₅ ) ₄ ), tetrapropoxysilane (alias: Tetrapropyl orthosilicate, silicon tetrapropoxide) (Si(OC ₃ H ₇ ) ₄ ), tetrabutoxysilane (alias: tetrabutyl orthosilicate, and silicon tetrabutoxide) (Si(OC ₄ H ₉ ) ₄ ) and more than one. In addition, it can also be an alkoxide obtained by substituting the alkoxy group of these alkoxides with other alkoxy groups, or it can also be a silicate oligomer that has been polymerized into 4-5 polymers. Alkyl silicate (for example, Ethyl Silicate 40 (trade name), Ethyl Silicate 48 (trade name), Methyl Silicate 51 (trade name) manufactured by COLCOAT Co., Ltd.). Among them, tetraethoxysilane (TEOS) is less harmful, easy to obtain and cheap, so it is preferable.

Specific examples of aluminum alkoxides (alkyl aluminates) include aluminum trimethoxide (Al(OCH ₃ ) ₃ ), aluminum triethoxide (Al(OC ₂ H ₅ ) ₃ ), Aluminum triisopropoxide (Al(O-iso-C ₃ H ₇ ) ₃ ), Aluminum tri-n-butoxide (Al(OnC ₄ H ₉ ) ₃ ), Aluminum tri-butoxide (Al(OsC ₄ One or more of H ₉ ) ₃ ), aluminum tri-tertiary butoxide (Al(OtC ₄ H ₉ ) ₃ ), etc.

Specific examples of zirconium alkoxides (alkyl zirconates) include zirconium tetraethoxide (Zr(OC ₂ H ₅ ) ₄ ), zirconium tetra-n-propoxide (Zr(OnC ₃ H ₇ ) ) ₄ ), zirconium tetraisopropoxide (Zr(O-iso-C ₃ H ₇ ) ₄ ), zirconium tetra-n-butoxide (Zr(OnC ₄ H ₉ ) ₄ ), zirconium tetra-tert-butoxide ( One or more of Zr(OtC ₄ H ₉ ) ₄ ), zirconium tetraisobutoxide (Zr(O-iso-C ₄ H ₉ ) ₄ ), and the like.

Specific examples of titanium alkoxides (alkyl titanates) include titanium tetramethoxide (Ti(OCH ₃ ) ₄ ), titanium tetraethoxide (Ti(OC ₂ H ₅ ) ₄ ) , Titanium tetraisopropoxide (Ti(O-iso-C ₃ H ₇ ) ₄ ), titanium tetraisobutoxide (Ti(O-iso-C ₄ H ₉ ) ₄ ), titanium tetra-n-butoxide ( One or more of Ti(OnC ₄ H ₉ ) ₄ ), titanium tetra-tertiary butoxide (Ti(OtC ₄ H ₉ ) ₄ ), titanium tetra-second butoxide (Ti(OsC ₄ H ₉ ) ₄ ), etc. .

As other metal alkoxides, boron alkoxides (alkyl borates), such as boron trimethoxide (B(OCH ₃ ) ₃ ), boron triethoxide (B(OC ₂ H ₅ ) ₃ ), boron tri-tertiary butoxide (B(OtC ₄ H ₉ ) ₃ ) and more.

The organic solvent used for the slurry in the insulation coating process is preferably one that forms a mixed solvent with water and that is easy to perform moderate drying. That is, those with high compatibility with water and relatively low boiling point (about 60°C to 90°C) are preferred. In addition, those with high safety, easy handling, easy acquisition, and low price are preferable. In view of the above, the modified alcohol with ethanol as the main component is preferred.

In the case of using silane oxide (Si(OR) ₄ , R: alkyl) as the metal alkoxide, the hydrolysis reaction and dehydration polycondensation reaction of the metal alkoxide in the insulation coating process will be described using the reaction formula.

In the hydrolysis reaction, under the coexistence of ammonia (NH ₃ ) and other alkali catalysts (alkali catalyst), as shown in the following formula (7), silicon atoms (Si) are directly attacked by nucleophilic hydroxyl ions (OH ^- ) , so that one alkoxy group (-OR) is hydrolyzed first. In this way, the charge on the silicon atom decreases and becomes more and more vulnerable to the attack of nucleophilic hydroxyl ions (OH ^- ). As a result, as shown in the following formula (8), the four alkoxy groups (—OR) were completely hydrolyzed to form silanol groups (Si—OH). In this way, if an alkali catalyst (alkali catalyst) is used, all the alkoxy groups (-OR) of the hydrolyzed silane oxide molecules will be hydrolyzed, so completely hydrolyzed molecules (Si(OH) ₄ ) and The state where completely unhydrolyzed molecules (Si(OR) ₄ ) coexist.

Si(OR) ₄ +H ₂ O[+OH ^- ] →Si(OH)(OR) ₃ +ROH[+OH ^- ]・・・(7) Si(OR) ₄ +4H ₂ O[+OH ^- ] →Si(OH) ₄ ＋4ROH[＋OH ^- ]・・・（8）

On the other hand, in the presence of an acid catalyst such as nitric acid (HNO ₃ ), as shown in the following formula (9) ^, the silicon atom (Si ) are vulnerable to water (H ₂ O) attack. Therefore, first an alkoxy group (-OR) undergoes hydrolysis to become a silanol group (Si-OH). In this way, the charge on the silicon atom and the charge on the oxygen atom (O) are reduced, so it is not easy to be attacked by the proton (H ⁺ ), and the detailed description is omitted. Therefore, the next hydrolysis will not occur immediately, but the alkoxy group (-OR) of other unhydrolyzed silane oxide molecules is easily hydrolyzed. In this way, when an acid catalyst is used, as shown in the following formula (10), the alkoxy groups (—OR) in all silane oxide molecules are hydrolyzed equally. Therefore, the following state is produced in the slurry, that is, there are no completely hydrolyzed molecules or completely unhydrolyzed molecules, but there are equally hydrolyzed molecules (Si(OH) _X (OR) _4-X ; 0<x<4 ).

Si(OR) ₄ +H ₂ O[+H ⁺ ] →Si(OH)(OR) ₃ +ROH[+H ⁺ ]・・・（9） Si(OR) ₄ +xH ₂ O[+H ⁺ ]→Si(OH) _X (OR) _4-X ＋xROH[＋H ⁺ ]・・・（10）（0＜x＜4）

As shown in the following formula (11), the dehydration polycondensation reaction is a reaction in which siloxane bonds (Si-O-Si) are formed through the dehydration polycondensation reaction of the silanol groups (Si-OH) between the hydrolyzed silane oxide molecules. , when the dehydration polycondensation reaction proceeds and ends, silicon dioxide (SiO ₂ ) is produced as shown in the following formula (12).

Si(OH) ₄ ＋Si(OH) ₄ →(OH) ₃ Si-O-Si(OH) ₃ ＋H ₂ O・・・（11） Si(OH) ₄ →SiO ₂ ＋2H ₂ O・・・（12）

Summarizing the above, when the hydrolysis and dehydration polycondensation of silane oxides are completed, silicon dioxide (SiO ₂ ) and alcohol are produced as shown in the following formula (13). For example, when tetraethoxysilane (TEOS: Si(OR) ₄ , R: C ₂ H ₅ ) is used, silicon dioxide (SiO ₂ ) and ethanol (C ₂ H ₅ OH) are produced.

Si(OR) ₄ ＋2H ₂ O→SiO ₂ ＋4ROH・・・（13）

As long as the silane oxide is hydrolyzed, regardless of the alkali catalyst (alkali catalyst) or acid catalyst, the above formula (13) is valid, and the form of silicon dioxide (SiO ₂ ) produced during the dehydration polycondensation is determined by the above The state of hydrolysis produced by the catalyst for hydrolysis has a great influence.

Regarding silane oxide molecules (Si(OH) _X (OR) _4-X ; 0<x<4) which are hydrolyzed equally by an acid catalyst, there are unhydrolyzed alkoxy groups (-OR) in the molecule. Therefore, if the silanol group (Si-OH) undergoes dehydration polycondensation between molecules, a hydrolyzed polymer formed by linear or branched linear polymers will be produced. If it is generated in the slurry in the insulating coating process, a hydrolyzed polymer of silane oxide is formed on the surface of the particles composed of iron oxide (FeO) or nickel oxide (NiO) in the crystallization powder. However, since they are polymerized in a linear or branched form, they are not easily densified in the solvent of the slurry, so it is not easy to form a dense insulating coating.

On the other hand, in the case of using an alkali catalyst (alkali catalyst), there are completely hydrolyzed molecules (Si(OH) ₄ ). Therefore, if the silanol group (Si-OH) undergoes dehydration polycondensation between molecules, a dense hydrolyzed polymer formed by polymerizing in a block shape will be produced. Therefore, even in the solvent of the slurry in the insulating coating process, a dense hydrolyzed polymer of silane oxide is formed on the surface of the particles composed of iron oxide (FeO) or nickel oxide (NiO) in the crystallization powder, The result is a dense insulating coating. Furthermore, in the case of using an alkali catalyst (alkali catalyst), there may be completely unhydrolyzed molecules (Si(OR) ₄ ). However, as described below, completely unhydrolyzed molecules or very small molecular weight particulate hydrolyzed polymers of silane oxides (silicon Sol), which will be removed out of the system together with the filtrate during the filtration and cleaning of the insulation coating step. Therefore, there is no influence on the insulating coating process.

Based on the above reasons, it is better to use an alkali catalyst (alkali catalyst) than an acid catalyst for the hydrolysis of the metal alkoxide in the insulating coating process. In this respect, a preferred catalyst is different from the case of applying a solvent to a base material. That is, when it is used as a binder for a coating solution that is applied to a substrate and dried in a solvent, instead of coating the particle surface in a solvent, it is preferable to use the above-mentioned acid catalyst to form a linear or branched Made of linear polymers.

Regarding the hydrolysis timing of the metal alkoxide in the insulating coating process, the following was explained before, that is, the hydrolysis is performed in a state where the crystallized powder and the metal alkoxide are uniformly mixed in the slurry. Hydrolysis with a catalyst. However, this embodiment is not limited to the aspect which hydrolyzes at this point. For example, it is also possible to prepare a metal oxide sol (silica sol in the case of a silane oxide) obtained by hydrolyzing a metal alkoxide with a hydrolysis catalyst in advance, and mix the metal oxide sol with crystallization powder And make slurry. The smaller the average molecular weight of the metal oxide sol is, about 500 to 5000, the less it will affect the hydrolysis time point of the metal alkoxide. The reason is that the bond between the iron oxide (FeO) or nickel oxide (NiO) on the surface of the crystallization powder and the hydrolyzed group of the metal oxide sol (silanol group (Si-OH) in the case of silane oxide) The result is that the particle surface of the crystallization powder is covered by smaller metal oxide sol particles, and then the sol particles are aggregated with each other.

From the viewpoint of uniformly forming an insulating coating in the insulating coating process, it is preferable to perform the process using a mixer for a slurry containing crystallization powder, water, an organic solvent, a metal alkoxide, and a catalyst for hydrolysis. Stirring based on stirring blades, or stirring based on container rotation using special rollers, etc. The treatment time or treatment temperature of the insulating coating treatment varies depending on the type of metal alkoxide applied or the thickness of the insulating coating required. For example, in general, the rate of hydrolysis of metal methoxides is greater than that of metal ethoxides. Therefore, the treatment time and treatment temperature are not particularly limited as long as they are appropriately set. For example, what is necessary is just to set the processing time at several hours to about one week, and to set the processing temperature at room temperature to 60°C. If the processing temperature is as high as about 40°C to 60°C, the processing speed can be increased to several times that at room temperature.

The thickness of the insulating coating also depends on the degree of insulation required, so it is not a one-size-fits-all. If it has to be said, it is preferably 1 nm to 30 nm, more preferably 2 nm to 25 nm, and still more preferably 3 nm to 20 nm. Even if it is too thick, it will only lead to insulation saturation, and on the other hand, the content ratio of the soft magnetic component will decrease, and magnetic properties such as saturation magnetic flux density will deteriorate. If the thickness is within the above range, the insulating function of the insulating coating can be exhibited without degrading the characteristics such as magnetic properties so much.

For the crystallized powder with insulating coating formed by the hydrolysis and dehydration polycondensation of metal alkoxides, use known separation devices such as Denver filter, filter press, centrifuge, or decanter, from slurry to Solid-liquid separation in the form of massive crystallization powder. The crystallized powder may also be cleaned during solid-liquid separation, etc., if necessary. When cleaning, only water, organic solvents such as alcohols with a relatively low boiling point, or mixed solvents thereof can be used as the cleaning liquid. As mentioned above, when there are metal alkoxides or their hydrolyzed polymers (non-hydrolyzed molecules or metal oxide sols with small molecular weights) remaining in the slurry that are not consumed by the insulating coating, they are equivalent to It is removed out of the system together with filtrate or cleaning waste during solid-liquid separation or cleaning.

Dry the bulk crystallized powder after solid-liquid separation and heat treatment if necessary, and recover the crystallized powder formed with an insulating coating made of high-resistance metal oxide. Regarding drying, there is no particular limitation as long as excessive oxidation during drying can be suppressed. However, it is suitable to use a drying device such as an inert gas environment dryer, a reducing gas environment dryer, or a vacuum dryer, as long as the temperature is 40°C to 150°C. The higher the drying temperature, the more the metal alkoxide hydrolyzed polymer constituting the insulating coating can be dehydrated and polycondensed to become a harder, denser and more insulating metal oxide. If further improvement is desired, heat treatment at a temperature exceeding 150° C. and below 450° C. may be performed in an inert gas atmosphere, a reducing gas atmosphere, or a vacuum. Furthermore, since the insulating coating has been formed, there is basically no need for slow oxidation treatment after drying.

Insulation coating treatment greatly improves the insulation of crystallization powder (alloy powder). For example, the powder resistivity (applied pressure: 64 MPa) of iron-nickel alloy powder without insulation coating treatment is generally 0.1 Ω・cm or less. Cloth treatment to form an insulating coating made of silicon dioxide (SiO ₂ ) with a thickness of about 0.015 μm (15 nm), the resistivity of the green powder is improved to above 10 ⁶ Ω·cm.

Thereby, the iron (Fe)-nickel (Ni) alloy powder of this embodiment can be manufactured. The manufacturing method of this embodiment is characterized by the use of a specific nucleating agent (a water-soluble salt of a metal that is more precious than nickel) that has the effect of miniaturizing the alloy powder, and has a reduction reaction promotion effect, a spheroidization promotion effect, and a surface Specific complexing agent (hydroxycarboxylic acid, etc.) for smoothing effect, so as to maintain the magnetic properties of the alloy powder after manufacture and improve the powder properties at the same time. Specifically, the average particle diameter of the alloy powder after manufacture can be freely controlled, and fine alloy powder can be obtained. Also, the obtained alloy powder has a narrow particle size distribution and uniform particle size. Furthermore, this alloy powder is spherical and has a smooth surface. Therefore, it is excellent in filling property. Also, the amount of hydrazine used can be suppressed by using an amine compound that functions as a self-decomposition inhibitor of hydrazine and a reduction reaction accelerator, but it is not limited. Therefore, reduction of manufacturing cost can be achieved, and the powder properties of the alloy powder can be made more excellent.

＜＜2. Iron-nickel alloy powder＞＞ The iron (Fe)-nickel (Ni) alloy powder of this embodiment contains at least iron (Fe) and nickel (Ni) as magnetic metals. In addition, the average particle size of the alloy powder is 0.10 μm to 0.60 μm, and the coefficient of variation (CV value) obtained from the average particle size and standard deviation in the number particle size distribution according to the following formula (14) is 25 %the following.

CV value (%) = standard deviation of particle size / average particle size × 100 ・・・（14）

The particle size distribution of the iron (Fe)-nickel (Ni) alloy powder in this embodiment is relatively small. Also, the average particle diameter of the alloy powder can be freely controlled. Therefore, miniaturization can be easily performed, and the particle size distribution can be made small. In addition, the alloy powder has a spherical shape, high surface smoothness, and excellent filling properties. The alloy powder of this embodiment having such advantages can be used for various electronic components such as noise filters, choke coils, inductors, and radio wave absorbers, and is especially suitable as a material for powder cores for choke coils or inductors .

The average particle size of the alloy powder is preferably from 0.10 μm to 0.60 μm, more preferably from 0.10 μm to 0.50 μm. By appropriately increasing the average particle size, deterioration of magnetic properties or reduction in filling properties due to surface oxidation can be suppressed. In addition, eddy current loss can be suppressed by appropriately reducing the average particle diameter.

The alloy powder preferably has a coefficient of variation (CV value) in particle size distribution of 25% or less, more preferably 20% or less, and still more preferably 15% or less. Here, the coefficient of variation is an index of uneven particle size, and the smaller the coefficient of variation, the narrower the particle size distribution. By keeping the coefficient of variation small, the number of coarse particles or excessively fine particles with large surface oxidation is reduced, so that excellent magnetic properties can be maintained and eddy current loss can be prevented from increasing. In addition, the coefficient of variation (CV value) was obtained by obtaining the average particle diameter and standard deviation in the number particle size distribution of the alloy powder, and using them, it was calculated according to the following formula (14).

CV value (%) = standard deviation of particle size / average particle size × 100 ・・・（14）

The alloy powder may also contain cobalt (Co) as needed. That is, the alloy powder may be an iron-nickel alloy powder containing only iron and nickel, or may be an iron-nickel-cobalt alloy powder containing iron, nickel, and cobalt. Iron, nickel and cobalt are all magnetic metals exhibiting ferromagnetism. Therefore, the iron-nickel alloy powder or iron-nickel-cobalt alloy powder has a high saturation magnetic flux density and excellent magnetic properties.

The ratios of iron (Fe), nickel (Ni) and cobalt (Co) contained in the alloy powder are not particularly limited. For example, the amount of iron (Fe) in the alloy powder is 10 mol% to 95 mol%, the amount of nickel (Ni) is 5 mol% to 90 mol%, and the amount of cobalt (Co) is 0 mol% or more Below 40 mol%. The amount of iron may be not less than 25 mol % and not more than 90 mol %, and may be not less than 40 mol % and not more than 80 mol %. In addition, the amount of nickel may be not less than 10 mol % and not more than 75 mol %, and may be not less than 20 mol % and not more than 60 mol %. The amount of cobalt may be not less than 5 mol % and not more than 20 mol %. However, the total amount of iron, nickel and cobalt is 100 mol% or less.

The powder density of the alloy powder depends on the composition or particle size of the alloy powder. If the iron content ratio is large, the specific gravity of the alloy becomes smaller, so the powder density of the alloy powder decreases. Also, if the particle size is small, Then the particles become difficult to fill with each other, and similarly the density of the compacted powder of the alloy powder tends to decrease. Therefore, for an iron-nickel alloy powder having an average particle size of 0.3 μm to 0.5 μm and a specific gravity of 8.2 to 8.3, the iron-nickel alloy powder having an iron content ratio of 45 mol% to 60 mol% of iron (Fe) has a green compact density ( Applied pressure: 100 MPa) is preferably 3.60 g/cm ³ or more, more preferably 3.70 g/cm ³ or more. In addition, if the iron-nickel alloy powder with an average particle size of 0.3 μm to 0.5 μm and a specific gravity of 7.9 to 8.0 has an iron content ratio of 10 mol% to 20 mol% of iron (Fe), the compacted powder density ( Applied pressure: 100 MPa) is preferably at least 3.45 g/cm ³ , more preferably at least 3.55 g/cm ³ . Regarding the particle size of the alloy powder, if the average particle size is refined from 0.3 μm to 0.5 μm to about 0.2 μm to 0.25 μm, the density of the compacted powder (applied pressure: 100 MPa) tends to decrease to about 0.1 g/cm ³ . By increasing the density of the powder compact, it is possible to produce a powder core having excellent magnetic properties (magnetic flux density).

The crystallite diameter of the alloy powder is preferably less than 30 nm, more preferably less than 10 nm. By appropriately suppressing the crystallite diameter to be smaller, it has the effect of easily obtaining a smaller coercive force like amorphous soft magnetic materials.

Preferably, the saturation magnetic flux density of the alloy powder is above 1 T (Tesla), and the coercive force is below 2000 A/m. By increasing the saturation magnetic flux density of the alloy powder, the magnetic properties (magnetic flux density) of the dust core can be improved. Also, by suppressing the coercive force of the alloy powder, an increase in hysteresis loss can be prevented. The saturation magnetic flux density is more preferably at least 1.2 T, further preferably at least 1.5 T (Tesla). The coercive force is more preferably at most 1600 A/m, further preferably at most 1200 A/m.

The method for producing the alloy powder of this embodiment is not limited as long as it satisfies the above requirements. However, one produced by the above-mentioned method is preferred.

As mentioned above, compared with nickel ions (or nickel hydroxide) or cobalt ions (or cobalt hydroxide), iron ions (or iron hydroxide) are less likely to be reduced. Fe)-nickel (Ni) alloy powder (for example, the iron content of the alloy powder exceeds 60 mole%), it is easy to form the following gradient structure (or core-shell structure) in the particle, that is, the center of the particle is rich in nickel Or the composition of cobalt, the closer to the particle surface, the more iron-rich composition. The composition in the particle tends to become non-uniform.

Regarding how the uneven composition in the particles affects the properties of the alloy powder, it will not have a significant impact on the magnetic properties (saturation magnetic flux density, coercive force, etc.). The reason is that, for example, the saturation magnetic flux density is positively correlated with the content ratio of iron (the higher the content ratio of iron, the saturation magnetic flux density also increases), so even if the composition becomes uneven in the particle and iron is formed The area where the content ratio is greater than the average value and the area less than the average value, and the saturation magnetic flux density also forms a region higher than the average value and an area smaller than the average value. From the perspective of the overall average value of the alloy powder, it is related to the uneven composition There is almost no change in the situation. Also, regarding the retention force, the composition dependence in the iron-nickel (-cobalt) system is not so great originally, and the degree of compositional non-uniformity generated in the particles does not change much.

On the other hand, the uneven composition in the above-mentioned particles may affect chemical and physical properties such as oxidation resistance and thermal expansion rate. As an example of this, if the surface of the particles becomes a composition richer in iron due to the gradient structure, oxidation will easily proceed and the oxidation resistance may deteriorate. However, by the above-mentioned In the case of modifying the particle surface to a nickel-rich composition, it may be possible to improve the oxidation resistance. Secondly, regarding the thermal expansion rate, the thermal expansion rate of the iron-nickel alloy is different from the saturation magnetic flux density, and there is no positive or negative correlation with the iron content ratio. ) near the characteristic that the thermal expansion rate becomes very small, and the low thermal expansion rate alloy of this composition is called an invar alloy (65 mol% of iron and 35 mol% of nickel as the main components). In the case of this composition, if the composition is not uniform in the particles, the thermal expansion rate will not be small no matter in the region where the iron content is greater than 65 mol% or the region where the iron content is less than 65 mol%. When the (Fe)-nickel (Ni) alloy powder is used as the constant alloy powder, it is necessary to make the composition uniform by the above-mentioned high-temperature heat treatment or the like.

As far as the inventors of the present invention know, there is no method for producing such iron-nickel alloy powder with excellent properties easily and cheaply. For example, although Patent Document 3 proposes a method for producing nickel-iron alloy nanoparticles by a wet method, this method does not use a nucleating agent composed of a water-soluble salt of a metal that is biased towards the noble metal side compared to nickel. , or complexing agents composed of hydroxycarboxylic acids, etc. Therefore, it is estimated that the powder properties (particle size, particle size distribution, sphericity, and particle surface properties) of the alloy powder produced by this method are not good. In fact, Patent Document 3 shows a transmission electron micrograph of a fine powder as an example sample (Fig. 1 of Patent Document 3), and it is estimated from the photograph that the coefficient of variation (CV value) in the particle size distribution of the fine powder is lower than that of Large, about 35%.

In addition, in the method of Patent Document 3 that does not use a nucleating agent or complexing agent, it is necessary to use a large amount of reducing agent (hydrazine) in order to obtain fine alloy powder. In fact, in the example of Patent Document 3, alloy nanoparticles were produced using 16.6 g of nickel chloride hexahydrate, 4.0 g of ferrous chloride tetrahydrate, and 135 g of hydrazine monohydrate as raw materials. In conversion from this blending amount, a large amount of hydrazine was blended in a molar ratio of about 30 times with respect to the total amount of iron and nickel. Such a method requiring a large amount of hydrazine is not practical since the cost of the reducing agent will increase significantly.

As long as the alloy powder of this embodiment satisfies the above-mentioned requirements, its usage is not limited. The alloy powder may be used alone or mixed with other inorganic materials and/or organic materials. For example, a powder compact containing alloy powder alone can be produced. Alternatively, alloy powder and ferrite powder can also be mixed to form a metal-ferrite composite material. In this case, the higher saturation magnetic flux density of the alloy powder and the higher electrical resistance of the ferrite can be used in a complementary manner. In addition, alloy powder and organic resin may be mixed and kneaded to produce a metal-organic resin composite material. By using this composite material, it is possible to obtain a composite body having excellent magnetic properties and a high degree of freedom in shape and high dimensional accuracy.

It is preferable to apply the alloy powder to a compact or tablet. The powder compact or sheet contains the alloy powder described above. Pressed powder system is produced by pressing alloy powder, or a mixture of alloy powder and other components, such as compression molding. Examples of other components include inorganic materials other than alloy powder, organic materials, and additives such as lubricants. In addition, heat treatment may be performed on the powder compact after press molding to remove the strain received during the molding. The sheet can be produced by adding a solvent and, if necessary, additives such as a binder to the alloy powder to form a paste, and forming or coating the obtained paste on a substrate. , thus making slices.

The alloy powder of this embodiment is suitable for magnetic devices because of its excellent magnetic properties. As such a magnetic device, an inductor, a reactor, a choke coil, a noise filter, a transformer, a rotating machine, a generator, or a radio wave absorber, etc. are mentioned. Inductors, reactors, choke coils, noise filters, transformers, rotary machines, generators, or radio wave absorbers include the above-mentioned compressed powder and/or sheet. In addition, the magnetic device may be a chip component such as a chip inductor.

FIG. 7 shows an example in which a powder compact containing alloy powder is applied to an inductor (loop coil). The inductor (10) is composed of a ring-shaped powder core body (12) and a coil (14) arranged to surround the powder core body (12). Also, input and output terminals (16a, 16b) are provided at both ends of the coil (14). The pressed powder core (12) can be produced by pressing alloy powder and, if necessary, additives such as a lubricant. The coil (14) can be wound around the powder compact core (12) by using a wire. In order to prevent conduction between the compressed powder core (12) and the coil (14), it is ideal to use a coated wire to make the coil (14), or to interpose an insulating sheet between the compressed powder core (12) and the coil (14) BETWEEN.

An example of applying the powder compact to a chip inductor is shown in FIG. 8 . A chip inductor (20) is composed of a powder core body (22) and a coil (24) embedded in the powder core body (22). The chip inductor (20) can be produced by prefabricating the coil (24), and pressurizing the coil (24) together with the alloy powder to integrally form it.

An example of applying the compact to a reactor is shown in FIG. 9 . The reactor (30) is provided with: a compressed powder core (32), a first coil (34) arranged as a sheet surrounding one side of the compressed powder core (32), a The second coil (36) arranged in the form of a piece on the other side of (32), and the connection part (38) electrically connecting the first coil (34) and the second coil (36).

FIG. 10 shows an example of applying the powder compact to a stator of a rotating machine (motor) or a generator. In addition, the direction of the magnetic flux at the time of operation is shown by the arrow in a figure. The stator (40) has a powder compact core (42) and windings (44). The winding (44) is arranged to surround each of the plurality of protrusions of the core (42), and the plurality of protrusions are arranged inside the compact core (42).

FIG. 11 shows an example of applying the powder compact to a rotor of a rotating machine (motor) or a generator. The rotor (50) has a powder compact core (52), windings (54) and an output shaft (56). The winding (54) is arranged to surround each of the plurality of protrusions of the core (52), and the plurality of protrusions are arranged on the outer side of the compact core (52). Also, the output shaft (56) is fixed at the center of the powder compact core (52). [Example]

The present invention will be described in more detail using the following examples and comparative examples. However, the present invention is not limited to the following examples.

(1) Production of iron-nickel alloy powder [Example 1] In Example 1, iron-nickel alloy powder (iron-nickel alloy powder) containing 50 mol % of iron (Fe) and 50 mol % of nickel (Ni) was produced according to the procedure shown in FIG. 5 . In Example 1, when preparing a reaction liquid, the reducing solution of normal temperature was added to the metal salt raw material solution heated using the water bath, and it mixed.

<Preparation procedure> Prepare ferrous chloride tetrahydrate (FeCl ₂ 4H ₂ O, molecular weight: 198.81, reagent manufactured by Wako Pure Chemical Industries, Ltd.) as a water-soluble iron salt, and prepare nickel chloride hexahydrate (NiCl ₂・6H ₂ O, molecular weight: 237.69, reagent manufactured by Wako Pure Chemical Industries, Ltd.) as a water-soluble nickel salt. Also, ammonium palladium(II) chloride (another name: ammonium tetrachloropalladate(II)) ((NH ₄ ) ₂ PdCl ₄ , molecular weight: 284.31, reagent manufactured by Wako Pure Chemical Industries, Ltd.) was prepared as a nucleating agent, Prepare trisodium citrate dihydrate (Na ₃ (C ₃ H ₅ O(COO) ₃ )・2H ₂ O, molecular weight: 294.1, reagent manufactured by Wako Pure Chemical Industries, Ltd.) as a complexing agent, and prepare commercially available industrial grade 60% by mass of hydrazine hydrate (manufactured by MGC Otsuka Chemical Co., Ltd.) was used as a reducing agent, and sodium hydroxide (NaOH, molecular weight: 40.0, reagent manufactured by Wako Pure Chemical Industries, Ltd.) was prepared as a pH regulator. 60% by mass of hydrazine hydrate is obtained by diluting hydrazine hydrate (N ₂ H ₄ ·H ₂ O, molecular weight: 50.06) to 1.67 times with pure water. Furthermore, ethylenediamine (EDA; H ₂ NC ₂ H ₄ NH ₂ , molecular weight: 60.1, reagent manufactured by Wako Pure Chemical Industries, Ltd.) was prepared as an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution A preparation containing ferrous chloride tetrahydrate (water-soluble iron salt), nickel chloride hexahydrate (water-soluble nickel salt), palladium (II) ammonium chloride (nucleating agent), trisodium citrate dihydrate ( Complexing agent) and metal salt raw material solution of water. At this time, weighing was performed so that the amount of palladium (Pd) relative to the total amount of magnetic metals (Fe and Ni) in the obtained metal salt raw material solution became 0.037 mass ppm (0.02 mol ppm). Moreover, it weighed so that the amount of trisodium citrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.362 (36.2 mol%) by molar ratio. Specifically, ferrous chloride tetrahydrate: 173.60 g, nickel chloride hexahydrate: 207.55 g, palladium (II) ammonium chloride: 9.93 μg, and trisodium citrate dihydrate: 185.9 g were dissolved in Pure water: Prepare metal salt stock solution in 1200 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) in the reaction liquid prepared in the subsequent crystallization step would be 4.85 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe and Ni) might become 4.96 in molar ratio. Specifically, sodium hydroxide: 346 g was dissolved in pure water: 850 mL to prepare a sodium hydroxide solution, and 60% by mass of hydrazine hydrate: 707 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that in the reaction solution prepared in the subsequent crystallization step, the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) becomes 0.01 (1.0 molar ratio) in terms of molar ratio. ear%) trace amount. Specifically, ethylenediamine: 1.05 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of reaction solution and precipitation of crystallization powder Put the prepared metal salt raw material solution into a Teflon (registered trademark) coated stainless steel container (reaction tank) with stirring wings installed in a water bath to It heated while stirring so that liquid temperature might become 70 degreeC. Then, to the heated metal salt raw material solution in the water bath, add and mix the reducing agent solution at a liquid temperature of 25° C. for 10 seconds to obtain a reaction liquid at a liquid temperature of 55° C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 32.3 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 55 degreeC). As shown in Fig. 12, the temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 70°C 10 minutes after the start of the reaction (reaction holding temperature of 70°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction solution. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 20 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.41 μm.

[Example 2] In Example 2, according to the sequence shown in Figure 3, the iron-nickel alloy powder (Fe - nickel-cobalt alloy powder). In Example 2, when preparing the reaction solution, first add the normal temperature pH adjustment solution (alkali metal hydroxide solution) to the metal salt raw material solution heated in a water bath, then add the normal temperature reducing agent solution and mix .

<Preparation steps> The same raw materials as in Example 1 were prepared as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a complexing agent, a reducing agent, a pH regulator, and an amine compound. In addition, cobalt chloride hexahydrate (CoCl ₂ ·6H ₂ O, molecular weight: 237.93, reagent manufactured by Wako Pure Chemical Industries, Ltd.) was also prepared as a water-soluble cobalt salt.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Prepare ferrous chloride tetrahydrate (water-soluble iron salt), nickel chloride hexahydrate (water-soluble nickel salt), cobalt chloride hexahydrate (water-soluble cobalt salt), palladium(II) ammonium chloride ( Nucleating agent), trisodium citrate dihydrate (complexing agent) and metal salt raw material solution of water. At this time, weighing is performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution becomes 0.037 mass ppm (0.02 mole ppm) relative to the total amount of magnetic metals (Fe, Ni, and Co). . Moreover, it weighed so that the amount of trisodium citrate with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 0.362 (36.2 mol%) in molar ratio. Specifically, ferrous chloride tetrahydrate: 173.60 g, nickel chloride hexahydrate: 166.04 g, cobalt chloride hexahydrate: 41.55 g, palladium (II) ammonium chloride: 9.93 μg, and citric acid Trisodium dihydrate: 185.9 g was dissolved in pure water: 1200 mL to prepare a metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising hydrazine (reducing agent) and water was prepared. At this time, the amount of hydrazine blended was set so that the molar ratio to the total amount of magnetic metals (Fe, Ni, and Co) in the reaction solution prepared in the subsequent crystallization step became 4.85. Specifically, 60% by mass hydrazine hydrate: 707 g was weighed to prepare a reducing agent solution.

(c) Preparation of pH adjustment solution (alkali metal hydroxide solution) A pH adjusting solution (alkali metal hydroxide solution) comprising sodium hydroxide (pH adjusting agent) and water is prepared. At this time, weighing was performed so that the amount of sodium hydroxide relative to the total amount of magnetic metals (Fe, Ni, and Co) in the reaction solution prepared in the subsequent crystallization step became 4.96 in molar ratio. Specifically, sodium hydroxide: 346 g was dissolved in pure water: 850 mL to prepare a pH adjustment solution.

(d) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that in the reaction solution prepared in the subsequent crystallization step, the blending amount of ethylenediamine relative to the total amount of magnetic metals (Fe, Ni, and Co) becomes A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.05 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. It heated while stirring so that liquid temperature might become 70 degreeC. Then, add and mix the pH adjustment solution (alkali metal hydroxide solution) with a liquid temperature of 25°C for 10 seconds to the heated metal salt raw material solution in the water bath, and then continue to mix for 10 seconds A reducing agent solution with a liquid temperature of 25°C was added and mixed to obtain a reaction liquid with a liquid temperature of 55°C. The concentration of magnetic metals (Fe, Ni and Co) in the reaction solution was 32.3 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 55 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 70°C 10 minutes after the start of the reaction (reaction holding temperature of 70°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is considered to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) and co-precipitates of cobalt hydroxide (Co(OH) ₂ ). Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, iron-nickel-cobalt crystallization powder is precipitated into the reaction liquid. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 20 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron component, nickel component and cobalt component in the reaction solution are all reduced to metallic iron, metallic nickel and metallic cobalt. The reaction liquid after the reaction is a slurry containing iron-nickel-cobalt crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and blocky iron-nickel-cobalt crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel-cobalt alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.33 μm.

[Example 3] In Example 3, iron-nickel alloy powder (iron-nickel alloy powder) containing 50 mol % of iron (Fe) and 50 mol % of nickel (Ni) was produced according to the procedure shown in FIG. 5 . In Example 3, when preparing a reaction liquid, the reduction solution of normal temperature was added to the metal salt raw material solution heated using the water bath, and it mixed.

<Preparation procedure> The same raw materials as in Example 1 were prepared as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a reducing agent, a pH regulator, and an amine compound. Also, tartaric acid ((CH(OH)COOH) ₂ , molecular weight: 150.09, reagent manufactured by Wako Pure Chemical Industries, Ltd.) was prepared instead of trisodium citrate dihydrate as a complexing agent.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Prepare ferrous chloride tetrahydrate (water-soluble iron salt), nickel chloride hexahydrate (water-soluble nickel salt), palladium (II) ammonium chloride (nucleating agent), tartaric acid (complexing agent) and water Metal salt raw material solution. At this time, weighing was performed such that the amount of palladium (Pd) in the obtained metal salt raw material solution was 0.037 mass ppm (0.02 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the amount of tartaric acid with respect to the total amount of magnetic metal (Fe and Ni) might become 0.200 (20.0 mol%) by molar ratio. Specifically, ferrous chloride tetrahydrate: 173.60 g, nickel chloride hexahydrate: 207.55 g, palladium (II) ammonium chloride: 9.93 μg, and tartaric acid: 52.4 g were dissolved in pure water: 1200 mL And prepare metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) in the reaction liquid prepared in the subsequent crystallization step would be 4.85 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe and Ni) might become 4.96 in molar ratio. Specifically, sodium hydroxide: 346 g was dissolved in pure water: 850 mL to prepare a sodium hydroxide solution, and 60% by mass of hydrazine hydrate: 707 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution An amine compound solution was prepared in the same manner as in Example 1.

(d) Preparation of reaction solution and precipitation of crystallization powder Using the above-mentioned metal salt raw material solution, reducing agent solution, and amine compound solution, the preparation of the reaction solution and the precipitation of the crystallization powder were carried out in the same manner as in Example 1. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 33.0 g/L.

＜Recycling procedure＞ In the same manner as in Example 1, iron-nickel alloy powder (iron-nickel alloy powder) was produced from the slurry reaction solution obtained in the crystallization step. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.40 μm.

[Example 4] In Example 4, iron-nickel alloy powder (iron-nickel alloy powder) containing 56 mol% of iron (Fe) and 44 mol% of nickel (Ni) was prepared according to the procedure shown in FIG. 5 . In Example 4, when preparing a reaction liquid, the metal salt raw material solution of normal temperature was added to the reducing solution heated using the water bath, and it mixed.

<Preparation steps> The same raw materials as in Example 1 were prepared as a nucleating agent, a reducing agent, a pH regulator, a complexing agent, and an amine compound. Also, prepare ferrous sulfate heptahydrate (FeSO ₄ 7H ₂ O, molecular weight: 278.05, reagent manufactured by Wako Pure Chemical Industries, Ltd.) instead of ferrous chloride tetrahydrate as a water-soluble iron salt, and prepare nickel sulfate hexahydrate (NiSO ₄ ·6H ₂ O, molecular weight: 262.85, reagent manufactured by Wako Pure Chemical Industries, Ltd.) instead of nickel chloride hexahydrate as the water-soluble nickel salt.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution was 0.37 mass ppm (0.2 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the amount of the trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.318 (31.8 mol%) by molar ratio. Specifically, ferrous sulfate heptahydrate: 272.0 g, nickel sulfate hexahydrate: 202.0 g, palladium (II) ammonium chloride: 99.3 μg, and trisodium citrate dihydrate: 163.5 g were dissolved in pure water : Prepare metal salt raw material solution in 950 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) in the reaction solution prepared in the subsequent crystallization step would be 6.41 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe and Ni) might become 4.67 in molar ratio. Specifically, sodium hydroxide: 326 g was dissolved in pure water: 800 mL to prepare a sodium hydroxide solution, and 60% by mass of hydrazine hydrate: 934 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution An amine compound solution was prepared in the same manner as in Example 1.

(d) Preparation of reaction solution and precipitation of crystallization powder. Stir and heat so that the temperature becomes 70°C. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 59°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 32.6 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 59 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 70°C 10 minutes after the start of the reaction (reaction holding temperature of 70°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction solution. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 30 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.38 μm.

[Example 5] In Example 5, an iron-nickel alloy powder (iron-nickel alloy powder (iron- nickel alloy powder). At this time, an additional raw material liquid is added and mixed at the final stage of the crystallization step. Specifically, first, except that the blending amount of hydrazine as a reducing agent was different, the iron- Crystallization of nickel-based alloy powder (iron-nickel alloy powder), and adding and mixing a water-soluble nickel salt aqueous solution as an additional raw material solution to the reaction liquid during the crystallization.

＜Preparation steps＞ Prepare the same raw materials as in Example 4 as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a reducing agent, a pH regulator, a complexing agent, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution was 0.37 mass ppm (0.2 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.318 (31.8 mol%) by molar ratio. Specifically, ferrous sulfate heptahydrate: 272.0 g, nickel sulfate hexahydrate: 202.0 g, palladium (II) ammonium chloride: 99.3 μg, and trisodium citrate dihydrate: 163.5 g were dissolved in pure water : Prepare metal salt raw material solution in 950 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing is carried out in such a manner that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) at the start of the reaction in the reaction solution prepared in the subsequent crystallization step becomes 4.85 ( With respect to the total amount of magnetic metals (Fe and Ni) at the time of adding the additional raw material liquid, it becomes 4.41 in molar ratio). Also, the amount of sodium hydroxide relative to the total amount of magnetic metals (Fe and Ni) at the beginning of the reaction was 4.67 in molar ratio (relative to the total amount of magnetic metals (Fe and Ni) when adding additional raw material liquid, by Mole ratio meter becomes 4.24) to weigh. Specifically, sodium hydroxide: 326 g was dissolved in pure water: 800 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 707 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) after adding the additional raw material solution in the reaction solution in the subsequent crystallization step becomes, in molar ratio, A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.16 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of additional raw material solution An additional raw material solution containing nickel sulfate hexahydrate (water-soluble nickel salt) and water was prepared. At this time, weighing is carried out in such a manner that the amount of magnetic metal (Ni) in the additional raw material solution obtained is 0.175 mol, which is 1.747 mol of the total amount of magnetic metal (Fe and Ni) in the metal salt raw material solution. Ear is 0.10 times. Specifically, nickel sulfate hexahydrate: 46.0 g was dissolved in pure water: 200 mL to prepare an additional raw material solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. Stir and heat so that the temperature becomes 70°C. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 57°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 35.2 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 57 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 70°C 10 minutes after the start of the reaction (reaction holding temperature of 70°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction solution. From 11 minutes to 16 minutes after the start of the reaction, add the additional raw material solution little by little while adding and mixing, so as to promote the reduction of iron ions (or iron hydroxide) that are not easily reduced, and at the same time promote the reduction reaction so that The surface of the precipitated iron-nickel crystallization powder becomes a composition richer in nickel. The concentration of magnetic metals (Fe and Ni) in the reaction solution after adding the additional raw material solution was 32.8 g/L. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 30 minutes from the start of the reaction. It is considered that the reduction reaction is completely completed, and the iron components and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.40 μm.

[Example 6] In Example 6, for the crystallized powder obtained in Example 1, an ultra-small jet mill (Nippon Pneumatic Co., Ltd., JKE-30) was used as a spiral of dry crushing at a crushing gas pressure of 0.5 MPa. Jet crushing treatment to produce iron-nickel alloy powder (iron-nickel alloy powder) containing 50 mol% of iron (Fe) and 50 mol% of nickel (Ni). The obtained alloy powder had a steep particle size distribution as in Example 1, and the average particle size was 0.41 μm. In addition, the aggregated particles are reduced by the spiral jet disintegration treatment, the filling property is improved (the green compact density is increased), and the unevenness of the surface is reduced, and the surface is composed of spherical particles with a very smooth surface.

[Example 7] In Example 7, as follows, after the crystallization step, the slurry-like crystallization powder before drying is implemented as wet crushing as high-pressure fluid collision crushing treatment in the middle of the recovery step, thereby producing iron (Fe ) 50 mol% and nickel (Ni) 50 mol% iron-nickel alloy powder (iron-nickel alloy powder).

＜Recovery procedure (including disintegration procedure)＞ After filtering and cleaning the slurry reaction solution containing iron-nickel crystallization powder obtained in the same crystallization step as in Example 1, iron-nickel crystallization powder was prepared using pure water with a conductivity of 1 μS/cm The cleaning crystallization powder slurry with a concentration of 20% by mass. The above filtration and cleaning were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The above-mentioned cleaned crystallization powder slurry is passed through a high-pressure fluid collision crushing device (manufactured by SUGINO MACHINE; pressure: 200 MPa) in two paths to perform crushing treatment, and then perform solid-liquid separation treatment to recover massive iron-nickel crystallization pink. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, after cooling the dried crystallized powder to 35°C in a vacuum, nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallized powder to obtain iron-nickel alloy powder. The obtained alloy powder had a steep particle size distribution as in Example 1, and the average particle size was 0.41 μm. In addition, the aggregated particles are reduced by the high-pressure fluid collision crushing treatment, the filling property is improved (the green compact density is increased), and the unevenness of the surface is reduced, and the surface is composed of spherical particles with a very smooth surface.

[Example 8] In Example 8, high-temperature heat treatment was carried out on the crystallization powder obtained according to the procedure shown in FIG. Powder (iron-nickel alloy powder). In Example 8, when preparing the reaction liquid, the normal temperature metal salt raw material solution was added to the reduction solution heated using a water bath, and mixed.

＜Preparation steps＞ Prepare the same raw materials as in Example 4 as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a reducing agent, a pH regulator, a complexing agent, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution was 2.81 mass ppm (1.50 mol ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.724 (72.4 mol%) by molar ratio. Specifically, ferrous sulfate heptahydrate: 318.1 g, nickel sulfate hexahydrate: 161.9 g, palladium (II) ammonium chloride: 750.5 μg, and trisodium citrate dihydrate: 374.7 g were dissolved in pure water : Prepare metal salt raw material solution in 950 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) at the start of the reaction in the reaction solution prepared in the subsequent crystallization step became 8.98 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe and Ni) at the time of reaction start may become 7.07 in molar ratio. Specifically, sodium hydroxide: 497.5 g was dissolved in pure water: 1218 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 1318 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) after adding the additional raw material solution in the reaction solution in the subsequent crystallization step becomes, in molar ratio, A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.06 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of reaction solution and precipitation of crystallization powder. Heat it so that the temperature becomes 80°C while stirring. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 71°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 25.0 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 71 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 80°C 10 minutes after the start of the reaction (reaction holding temperature of 80°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction solution. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 40 minutes from the start of the reaction. It is considered that the reduction reaction is completely completed, and the iron components and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder.

＜High temperature heat treatment step＞ The crystallization powder thus obtained was subjected to a high-temperature heat treatment at 350°C for 60 minutes in a nitrogen atmosphere to produce an iron-nickel system containing 65 mol% of iron (Fe) and 35 mol% of nickel (Ni). Alloy powder (iron-nickel alloy powder). The obtained alloy powder had a steep particle size distribution as in Example 1, and the average particle size was 0.27 μm. In addition, the above-mentioned high-temperature heat treatment promotes the diffusion of Fe and Ni in the iron (Fe)-nickel (Ni) alloy particles, improves the composition uniformity in the particles, and reduces the characteristic unevenness in the particles.

[Example 9] In Example 9, an iron-nickel alloy powder (iron-nickel alloy powder (iron- nickel alloy powder). At this time, an additional raw material liquid is added and mixed in the middle of the crystallization step. Specifically, a metal salt raw material solution at room temperature was added and mixed to a reducing solution heated in a water bath to prepare a reaction solution. First, iron containing 67.4 mol% of iron (Fe) and 32.6 mol% of nickel (Ni) was advanced. - Crystallization of nickel-based alloy powder (iron-nickel alloy powder). And, in the middle of the crystallization, a water-soluble nickel salt aqueous solution was added to the reaction liquid and mixed as an additional raw material liquid.

＜Preparation steps＞ Prepare the same raw materials as in Example 4 as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a reducing agent, a pH regulator, a complexing agent, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution was 0.97 mass ppm (0.52 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.750 (75.0 mol%) by molar ratio. Specifically, ferrous sulfate heptahydrate: 318.1 g, nickel sulfate hexahydrate: 145.7 g, palladium (II) ammonium chloride: 250.0 μg, and trisodium citrate dihydrate: 374.7 g were dissolved in pure water : Prepare the metal salt raw material solution in 500 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing is carried out in such a manner that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) at the beginning of the reaction in the reaction solution prepared in the subsequent crystallization step becomes 7.62 ( With respect to the total amount of magnetic metals (Fe and Ni) at the time of adding the additional raw material liquid, it becomes 7.36 in molar ratio). Also, the amount of sodium hydroxide relative to the total amount of magnetic metals (Fe and Ni) at the start of the reaction was 7.33 in molar ratio (relative to the total amount of magnetic metals (Fe and Ni) when adding additional raw material liquid, by Mole ratio meter becomes 7.07) to weigh. Specifically, sodium hydroxide: 497.5 g was dissolved in pure water: 1218 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 1080 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) after adding the additional raw material solution in the reaction solution in the subsequent crystallization step becomes, in molar ratio, A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.06 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of additional raw material solution An additional raw material solution containing nickel sulfate hexahydrate (water-soluble nickel salt) and water was prepared. At this time, weighing is carried out in such a manner that the amount of magnetic metal (Ni) in the additional raw material solution obtained is 0.0616 mol, which is 1.760 mol of the total amount of magnetic metal (Fe and Ni) in the metal salt raw material solution. The ear is 0.035 times. Specifically, nickel sulfate hexahydrate: 16.2 g was dissolved in pure water: 200 mL to prepare an additional raw material solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. Heat it so that the temperature becomes 80°C while stirring. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 75°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 29.1 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 75 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 80°C 10 minutes after the start of the reaction (reaction holding temperature of 80°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction liquid. From 25 minutes to 35 minutes after the start of the reaction, add the additional raw material solution little by little while adding and mixing, so as to promote the reduction of iron ions (or iron hydroxide) that are not easily reduced, and at the same time promote the reduction reaction so that The surface of the precipitated iron-nickel crystallization powder becomes a composition richer in nickel. The concentration of magnetic metals (Fe and Ni) in the reaction solution after adding the additional raw material solution was 28.4 g/L. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 40 minutes from the start of the reaction. It is considered that the reduction reaction is completely completed, and the iron components and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.39 μm.

[Example 10] In Example 10, an iron-nickel alloy powder (iron-nickel alloy powder (iron- nickel alloy powder). At this time, an additional raw material liquid is added and mixed in the middle of the crystallization step. Specifically, a metal salt raw material solution at room temperature was added and mixed to a reducing solution heated in a water bath to prepare a reaction solution. First, iron containing 83.3 mol% of iron (Fe) and 16.7 mol% of nickel (Ni) was advanced. - Crystallization of nickel-based alloy powder (iron-nickel alloy powder). And, in the middle of the crystallization, a water-soluble nickel salt aqueous solution was added to the reaction liquid and mixed as an additional raw material liquid.

＜Preparation steps＞ Prepare the same raw materials as in Example 4 as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a reducing agent, a pH regulator, a complexing agent, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution became 0.79 mass ppm (0.42 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.754 (75.4 mol%) by molar ratio. Specifically, ferrous sulfate heptahydrate: 394.3 g, nickel sulfate hexahydrate: 74.6 g, palladium (II) ammonium chloride: 201.6 μg, and trisodium citrate dihydrate: 377.5 g were dissolved in pure water : 836 mL to prepare the metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing is carried out in such a manner that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) at the start of the reaction in the reaction solution prepared in the subsequent crystallization step becomes 9.40 ( With respect to the total amount of magnetic metals (Fe and Ni) at the time of adding the additional raw material liquid, it becomes 9.02 in molar ratio). Also, the amount of sodium hydroxide relative to the total amount of magnetic metals (Fe and Ni) at the start of the reaction was 7.37 in molar ratio (relative to the total amount of magnetic metals (Fe and Ni) when adding additional raw material liquid, by Mole ratio meter becomes 7.07) to weigh. Specifically, sodium hydroxide: 501.3 g was dissolved in pure water: 1228 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 1334 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) after adding the additional raw material solution in the reaction solution in the subsequent crystallization step becomes, in molar ratio, A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.07 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of additional raw material solution An additional raw material solution containing nickel sulfate hexahydrate (water-soluble nickel salt) and water was prepared. At this time, weighing is carried out in such a manner that the amount of magnetic metal (Ni) in the additional raw material solution obtained is 0.0709 mol, which is 1.773 mol of the total amount of magnetic metal (Fe and Ni) in the metal salt raw material solution. Ear is 0.04 times. Specifically, nickel sulfate hexahydrate: 18.64 g was dissolved in pure water: 200 mL to prepare an additional raw material solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. Heat it so that the temperature becomes 80°C while stirring. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 71°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 24.5 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 71 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 80°C 10 minutes after the start of the reaction (reaction holding temperature of 80°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction liquid. From 8 minutes after the start of the reaction to 18 minutes after the start of the reaction, add the additional raw material solution little by little while adding and mixing, so as to promote the reduction of iron ions (or iron hydroxide) that are not easily reduced, and at the same time promote the reduction reaction so that The surface of the precipitated iron-nickel crystallization powder becomes a composition richer in nickel. The concentration of magnetic metals (Fe and Ni) in the reaction solution after adding the additional raw material solution was 24.2 g/L. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 60 minutes from the start of the reaction. It is considered that the reduction reaction is completely completed, and the iron components and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.48 μm.

[Example 11] In Example 11, an iron-nickel alloy powder (iron-nickel alloy powder (iron- nickel alloy powder). At this time, an additional raw material liquid is added and mixed in the middle of the crystallization step. Specifically, a metal salt raw material solution at room temperature was added and mixed to a reducing solution heated in a water bath to prepare a reaction solution, and iron containing 91.8 mol% of iron (Fe) and 8.2 mol% of nickel (Ni) was first introduced. - Crystallization of nickel-based alloy powder (iron-nickel alloy powder). And, in the middle of the crystallization, a water-soluble nickel salt aqueous solution was added to the reaction liquid and mixed as an additional raw material liquid.

＜Preparation steps＞ Prepare the same raw materials as in Example 4 as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a reducing agent, a pH regulator, a complexing agent, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution was 0.77 mass ppm (0.41 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.369 (36.9 mol%) by molar ratio. Specifically, ferrous sulfate heptahydrate: 446.0 g, nickel sulfate hexahydrate: 37.5 g, palladium (II) ammonium chloride: 202.6 μg, and trisodium citrate dihydrate: 189.7 g were dissolved in pure water : Prepare the metal salt raw material solution in 720 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing is carried out in such a manner that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) at the beginning of the reaction in the reaction solution prepared in the subsequent crystallization step becomes 9.15 ( With respect to the total amount of magnetic metals (Fe and Ni) at the time of adding the additional raw material liquid, it becomes 8.97 in molar ratio). Also, the amount of sodium hydroxide relative to the total amount of magnetic metals (Fe and Ni) at the beginning of the reaction was 8.29 in molar ratio (relative to the total amount of magnetic metals (Fe and Ni) when adding additional raw material liquid, by The molar ratio meter becomes 8.13) for weighing. Specifically, sodium hydroxide: 579 g was dissolved in pure water: 1418 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 1334 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) after adding the additional raw material solution in the reaction solution in the subsequent crystallization step becomes, in molar ratio, A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.07 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of additional raw material solution An additional raw material solution containing nickel sulfate hexahydrate (water-soluble nickel salt) and water was prepared. At this time, weighing is carried out in such a manner that the amount of magnetic metal (Ni) in the additional raw material solution obtained is 0.0356 mol, which is 1.747 mol of the total amount of magnetic metal (Fe and Ni) in the metal salt raw material solution. Ear is 0.02 times. Specifically, nickel sulfate hexahydrate: 9.37 g was dissolved in pure water: 100 mL to prepare an additional raw material solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. Heat while stirring so that the temperature becomes 85°C. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 78°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 25.0 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 78 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 85°C 10 minutes after the start of the reaction (reaction holding temperature of 85°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction liquid. From 8 minutes after the start of the reaction to 18 minutes after the start of the reaction, add the additional raw material solution little by little while adding and mixing, so as to promote the reduction of iron ions (or iron hydroxide) that are not easily reduced, and at the same time promote the reduction reaction so that The surface of the precipitated iron-nickel crystallization powder becomes a composition richer in nickel. The concentration of magnetic metals (Fe and Ni) in the reaction solution after adding the additional raw material solution was 24.8 g/L. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 50 minutes from the start of the reaction. It is considered that the reduction reaction is completely completed, and the iron components and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.38 μm.

[Example 12] In Example ₁₂ , insulating coating treatment was performed on the crystallization powder obtained according to the procedure shown in FIG. Iron-nickel alloy powder (iron-nickel alloy powder) containing 55 mol% of iron (Fe) and 45 mol% of nickel (Ni). In Example 12, when preparing a reaction liquid, the metal salt raw material solution of normal temperature was added to the reducing solution heated using the water bath, and it mixed.

＜Preparation steps＞ The same raw materials as in Example 4 were prepared as water-soluble iron salt, water-soluble nickel salt, nucleating agent, reducing agent, pH regulator, complexing agent, and amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), palladium(II) ammonium chloride (nucleating agent), trisodium citrate dihydrate (complexing agent) ) and water metal salt raw material solution. At this time, weighing was performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution became 0.56 mass ppm (0.3 mole ppm) relative to the total amount of magnetic metals (Fe and Ni). Moreover, it weighed so that the amount of trisodium citrate dihydrate with respect to the total amount of magnetic metal (Fe and Ni) might become 0.543 (54.3 mol%) in molar ratio. Specifically, ferrous sulfate heptahydrate: 267.7 g, nickel sulfate hexahydrate: 207.1 g, palladium (II) ammonium chloride: 149.3 μg, and trisodium citrate dihydrate: 279.6 g were dissolved in pure water : Prepare metal salt raw material solution in 950 mL.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) in the reaction liquid prepared in the subsequent crystallization step would be 4.85 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe and Ni) might become 4.95 by molar ratio. Specifically, sodium hydroxide: 346 g was dissolved in pure water: 848 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 709 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(c) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that the amount of ethylenediamine relative to the total amount of magnetic metals (Fe and Ni) after adding the additional raw material solution in the reaction solution in the subsequent crystallization step becomes, in molar ratio, A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.05 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(d) Preparation of reaction solution and precipitation of crystallization powder. Stir and heat so that the temperature becomes 70°C. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 59°C. The concentration of magnetic metals (Fe and Ni) in the reaction solution was 33.9 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 59 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 70°C 10 minutes after the start of the reaction (reaction holding temperature of 70°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is believed to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) Co-precipitates. Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, the iron-nickel crystallization powder is precipitated into the reaction liquid. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 30 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron and nickel components in the reaction solution are all reduced to metallic iron and metallic nickel. The reaction solution after the reaction is a slurry containing iron-nickel crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and massive iron-nickel crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, a crystallized powder (iron-nickel alloy powder) was obtained as a dry powder. The obtained crystallization powder (alloy powder) is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.39 μm.

<Insulation coating step> Put 50.0 g of the crystallization powder (alloy powder) obtained in the recovery step above into a closed container made of polypropylene, and then add 7.0 g of pure water, ethanol (C ₂ H ₅ OH, molecular weight: 46.07 , Wako Pure Chemical Industries Co., Ltd.) 50.0 g, after dispersing the above crystallized powder (alloy powder) in a mixed solvent of water and ethanol, add tetraethoxysilane (another name: primary silicon) as a silane oxide Tetraethyl silicate, tetraethyl silicate) (abbreviation: TEOS) (Si(OC ₂ H ₅ ) ₄ , molecular weight: 208.33, reagent manufactured by Wako Pure Chemical Industries, Ltd.) 9.8 g was mixed thoroughly, and then 2.4 g of 1% by mass ammonia water as an alkali catalyst (alkali catalyst) for hydrolyzing silane oxide was added in a state of stirring to prepare a uniform slurry. Furthermore, the above-mentioned 1 mass % ammonia water is obtained by diluting 28-30 mass % ammonia water (NH ₃ , molecular weight: 17.03, reagent manufactured by Wako Pure Chemical Industries, Ltd.) of the reagent with pure water, crystallized powder (alloy powder ), water, ethanol, tetraethoxysilane, and 1% by mass ammonia water are all used at room temperature, and all addition and mixing are also performed at room temperature.

The above-mentioned slurry containing crystallization powder (alloy powder), water, ethanol, tetraethoxysilane, and ammonia was stored at 40°C for 2 days in a rotating polypropylene airtight container, and the slurry was pushed forward while stirring the slurry. The hydrolysis and dehydration polycondensation of ethoxysilane, and the hydrolysis polymer of tetraethoxysilane (although it contains a small amount of silanol group (Si-OH) but basically two Composition of silicon oxide (SiO ₂ )) as the main component of the insulating coating. Then, the slurry is subjected to filtration cleaning and solid-liquid separation treatment, and the massive crystallized powder (alloy powder) is recovered. Filtration washing was first performed using ethanol containing 50% by mass of pure water, and then using ethanol. Furthermore, the hydrolyzed polymer of tetraethoxysilane that is not consumed by the insulating coating on the particle surface of the crystallization powder (alloy powder) and remains in the slurry is a particle (silica sol) with a very small molecular weight. When it is removed as a filtrate, it does not remain in the recovered massive crystallization powder (alloy powder).

The recovered massive crystallized powder (alloy powder) was dried in a vacuum dryer at 50°C, and then heat-treated in vacuum at 150°C for 2 hours. Through this heat treatment, the hydrolyzed polymer of tetraethoxysilane that constitutes the insulating coating undergoes further dehydration and polycondensation to become harder and denser silicon dioxide (SiO ₂ ), and the insulating properties of the insulating coating are improved. further improvement. Through this insulating coating treatment, iron-nickel alloy powder having an insulating coating made of high-resistance silicon dioxide (SiO ₂ ) formed on the particle surface is obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep, with an average particle size of 0.42 μm, and the thickness of the insulating coating is estimated to be about 0.015 μm (about 15 nm). In addition, the electrical resistivity (applied pressure: 64 MPa) of the powder compact significantly increased from 0.04 Ω·cm before the insulating coating treatment to exceed the measurement range (>10 ⁷ Ω･cm) by the insulating coating treatment.

[Example 13] In Example 13, according to the order shown in Figure 5, the iron-nickel alloy powder (Fe - nickel-cobalt alloy powder). In Example 13, when preparing a reaction liquid, the metal salt raw material solution of normal temperature was added to the reducing solution heated using the water bath, and it mixed.

<Preparation steps> The same raw materials as in Example 4 were prepared as a water-soluble iron salt, a water-soluble nickel salt, a nucleating agent, a complexing agent, a reducing agent, a pH regulator, and an amine compound. In addition, cobalt sulfate heptahydrate (CoSO ₄ ·7H ₂ O, molecular weight: 281.103, reagent manufactured by Wako Pure Chemical Industries, Ltd.) was also prepared as a water-soluble cobalt salt.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), cobalt sulfate heptahydrate (water-soluble cobalt salt), palladium (II) ammonium chloride (nucleating agent ), trisodium citrate dihydrate (complexing agent) and metal salt raw material solution of water. At this time, weighing is performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution becomes 0.38 mass ppm (0.2 mole ppm) relative to the total amount of magnetic metals (Fe, Ni, and Co). . Moreover, it weighed so that the amount of trisodium citrate with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 0.362 (36.2 mol%) in molar ratio. Specifically, ferrous sulfate heptahydrate: 394.1 g, nickel sulfate hexahydrate: 46.6 g, cobalt sulfate heptahydrate: 49.8 g, palladium (II) ammonium chloride: 100.8 μg, and trisodium citrate di Hydrate: 188.7 g was dissolved in pure water: 1000 mL to prepare a metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe, Ni, and Co) in the reaction solution prepared in the subsequent crystallization step became 3.65 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 7.07 by molar ratio. Specifically, sodium hydroxide: 501 g was dissolved in pure water: 1227 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 540 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(d) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that in the reaction solution prepared in the subsequent crystallization step, the blending amount of ethylenediamine relative to the total amount of magnetic metals (Fe, Ni, and Co) becomes A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.07 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. It heated while stirring so that the liquid temperature might become 85 degreeC. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 70°C. The concentration of magnetic metals (Fe, Ni and Co) in the reaction solution was 31.2 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 70 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 85°C 10 minutes after the start of the reaction (reaction holding temperature of 85°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is considered to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) and co-precipitates of cobalt hydroxide (Co(OH) ₂ ). Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, iron-nickel-cobalt crystallization powder is precipitated into the reaction liquid. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 40 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron component, nickel component and cobalt component in the reaction solution are all reduced to metallic iron, metallic nickel and metallic cobalt. The reaction liquid after the reaction is a slurry containing iron-nickel-cobalt crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and blocky iron-nickel-cobalt crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel-cobalt alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.42 μm.

[Example 14] In Example 14, according to the order shown in Figure 5, the iron-nickel alloy powder (Fe - nickel-cobalt alloy powder). In Example 14, when preparing the reaction liquid, the normal temperature metal salt raw material solution was added to the reduction solution heated using a water bath, and mixed.

＜Preparation steps＞ The same raw materials as in Example 13 were prepared as a water-soluble iron salt, a water-soluble nickel salt, a water-soluble cobalt salt, a nucleating agent, a complexing agent, a reducing agent, a pH regulator, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), cobalt sulfate heptahydrate (water-soluble cobalt salt), palladium (II) ammonium chloride (nucleating agent ), trisodium citrate dihydrate (complexing agent) and metal salt raw material solution of water. At this time, weighing is performed so that the amount of palladium (Pd) in the obtained metal salt raw material solution becomes 0.38 mass ppm (0.2 mole ppm) relative to the total amount of magnetic metals (Fe, Ni, and Co). . Moreover, it weighed so that the amount of trisodium citrate with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 0.362 (36.2 mol%) in molar ratio. Specifically, ferrous sulfate heptahydrate: 343.0 g, nickel sulfate hexahydrate: 46.3 g, cobalt sulfate heptahydrate: 99.1 g, palladium (II) ammonium chloride: 100.2 μg, and trisodium citrate di Hydrate: 187.6 g was dissolved in pure water: 1100 mL to prepare a metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe, Ni, and Co) in the reaction solution prepared in the subsequent crystallization step became 1.46 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 7.07 by molar ratio. Specifically, sodium hydroxide: 499 g was dissolved in pure water: 1221 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 215 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(d) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that in the reaction solution prepared in the subsequent crystallization step, the blending amount of ethylenediamine relative to the total amount of magnetic metals (Fe, Ni, and Co) becomes in molar ratio A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.06 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. It heated while stirring so that the liquid temperature might become 85 degreeC. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 67°C. The concentration of magnetic metals (Fe, Ni and Co) in the reaction solution was 33.7 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 67 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 85°C 10 minutes after the start of the reaction (reaction holding temperature of 85°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is considered to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) and co-precipitates of cobalt hydroxide (Co(OH) ₂ ). Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, iron-nickel-cobalt crystallization powder is precipitated into the reaction liquid. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 40 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron component, nickel component and cobalt component in the reaction solution are all reduced to metallic iron, metallic nickel and metallic cobalt. The reaction liquid after the reaction is a slurry containing iron-nickel-cobalt crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and blocky iron-nickel-cobalt crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel-cobalt alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.40 μm.

[Example 15] In Example 15, according to the order shown in Figure 5, the iron-nickel alloy powder (Fe - nickel-cobalt alloy powder). In Example 15, when preparing the reaction liquid, the normal temperature metal salt raw material solution was added to the reduction solution heated using a water bath, and mixed.

＜Preparation steps＞ The same raw materials as in Example 13 were prepared as a water-soluble iron salt, a water-soluble nickel salt, a water-soluble cobalt salt, a nucleating agent, a complexing agent, a reducing agent, a pH regulator, and an amine compound.

＜Crystalization step＞ (a) Preparation of metal salt raw material solution Preparation of ferrous sulfate heptahydrate (water-soluble iron salt), nickel sulfate hexahydrate (water-soluble nickel salt), cobalt sulfate heptahydrate (water-soluble cobalt salt), palladium (II) ammonium chloride (nucleating agent ), trisodium citrate dihydrate (complexing agent) and metal salt raw material solution of water. At this time, weighing is carried out so that the amount of palladium (Pd) becomes 0.37 mass ppm (0.2 mole ppm) relative to the total amount of magnetic metals (Fe, Ni, and Co) in the obtained metal salt raw material solution. . Moreover, it weighed so that the amount of trisodium citrate with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 0.362 (36.2 mol%) in molar ratio. Specifically, ferrous sulfate heptahydrate: 317.6 g, nickel sulfate hexahydrate: 46.2 g, cobalt sulfate heptahydrate: 123.5 g, palladium (II) ammonium chloride: 100.0 μg, and trisodium citrate di Hydrate: 187.1 g was dissolved in pure water: 1100 mL to prepare a metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe, Ni, and Co) in the reaction solution prepared in the subsequent crystallization step became 1.47 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the total amount of magnetic metal (Fe, Ni, and Co) might become 7.07 by molar ratio. Specifically, sodium hydroxide: 497 g was dissolved in pure water: 1216 mL to prepare a sodium hydroxide solution, and 60 mass % hydrazine hydrate: 215 g was added to the sodium hydroxide solution to prepare a reducing agent solution.

(d) Preparation of amine compound solution Prepare an amine compound solution containing ethylenediamine (amine compound) and water. At this time, weighing is carried out in such a manner that in the reaction solution prepared in the subsequent crystallization step, the blending amount of ethylenediamine relative to the total amount of magnetic metals (Fe, Ni, and Co) becomes A trace amount of 0.01 (1.0 mole %). Specifically, ethylenediamine: 1.06 g was dissolved in pure water: 18 mL to prepare an amine compound solution.

(e) Preparation of reaction solution and precipitation of crystallization powder. It heated while stirring so that the liquid temperature might become 85 degreeC. Then, to the reducing agent solution heated in the water bath, the metal salt raw material solution with a liquid temperature of 25°C was added and mixed with a mixing time of 10 seconds to obtain a reaction liquid with a liquid temperature of 67°C. The concentration of magnetic metals (Fe, Ni and Co) in the reaction solution was 33.7 g/L. Thereby, reduction reaction (crystallization reaction) was started (reaction initiation temperature 67 degreeC). The temperature of the reaction liquid continued to rise by heating the water bath after the start of the reaction, and was maintained at a liquid temperature of 85°C 10 minutes after the start of the reaction (reaction holding temperature of 85°C). The hue of the reaction solution was dark green immediately after the reaction (preparation of the reaction solution), but turned dark gray after a few minutes. The reason why the color tone becomes dark green immediately after the reaction starts is considered to be that iron hydroxide (Fe(OH) ₂ ) and nickel hydroxide (Ni(OH) ) ₂ ) and co-precipitates of cobalt hydroxide (Co(OH) ₂ ). Also, the reason why the color tone changed to dark gray several minutes after the start of the reaction is considered to be due to nucleation by the action of the nucleating agent (palladium salt).

Within 10 minutes from 3 minutes to 13 minutes after the start of the reaction when the color tone of the reaction solution changed to dark gray, the amine compound solution was added dropwise to the reaction solution and mixed to advance the reduction reaction. Thereby, iron-nickel-cobalt crystallization powder is precipitated into the reaction liquid. The color tone of the reaction solution at this time was black, but the supernatant of the reaction solution became transparent within 30 minutes from the start of the reaction. It is considered that the reduction reaction of the above formula (6) is completed, and the iron component, nickel component and cobalt component in the reaction solution are all reduced to metallic iron, metallic nickel and metallic cobalt. The reaction liquid after the reaction is a slurry containing iron-nickel-cobalt crystallization powder.

＜Recycling procedure＞ The slurry-like reaction liquid obtained in the crystallization step is subjected to filtration cleaning and solid-liquid separation treatment, and blocky iron-nickel-cobalt crystallization powder is recovered. Filtration and washing were performed using pure water with a conductivity of 1 μS/cm until the conductivity of the filtrate obtained by filtering the slurry became 10 μS/cm or less. The recovered bulk crystallization powder was dried in a vacuum dryer set at 50°C. Then, the dried crystallization powder was cooled to 35° C. in a vacuum, and nitrogen gas containing 1.0% by volume of oxygen was supplied to slowly oxidize the crystallization powder. Thereby, iron-nickel-cobalt alloy powder was obtained. The obtained alloy powder is composed of spherical particles with smooth surface. The particle size distribution is steep with an average particle size of 0.42 μm.

[Comparative example 1] In Comparative Example 1, ammonium palladium(II) chloride (nucleating agent) was not mixed when preparing the metal salt raw material solution. In addition, by preparing the reaction solution and the precipitation of the crystallization powder in the same manner as in Example 1, an iron-nickel alloy containing 50 mol% of iron (Fe) and 50 mol% of nickel (Ni) was produced. Powder (iron-nickel alloy powder). The concentration of magnetic metals (Fe and Ni) in the reaction solution was 32.3 g/L. The obtained alloy powder is composed of spherical particles, and the surface of the particles is uneven. The particle size distribution is steep with an average particle size of 0.65 μm.

[Comparative example 2] In Comparative Example 2, trisodium citrate dihydrate (complexing agent) was not blended when preparing the metal salt raw material solution. In addition, the preparation of the reaction solution and the precipitation of the crystallization powder were carried out in the same manner as in Example 1 to prepare an iron-nickel alloy containing 50 mol% of iron (Fe) and 50 mol% of nickel (Ni). Powder (iron-nickel alloy powder). The concentration of magnetic metals (Fe and Ni) in the reaction solution was 33.3 g/L. The obtained alloy powder is composed of particles with distorted shape, and the surface of the particles is uneven. The particle size distribution is wide, with an average particle size of 0.26 μm.

[Comparative example 3] In Comparative Example 3, palladium(II) ammonium chloride (nucleating agent) and trisodium citrate dihydrate (complexing agent) were not mixed when preparing the metal salt raw material solution. Also, when preparing the reducing agent solution, a large amount of hydrazine (reducing agent) was blended. Except for this, iron-nickel alloy powder (iron-nickel alloy powder) was produced in the same manner as in Example 1. The preparation of the metal salt raw material solution and the reducing agent solution is carried out as follows.

(a) Preparation of metal salt raw material solution A metal salt raw material solution comprising ferrous chloride tetrahydrate (water-soluble iron salt), nickel chloride hexahydrate (water-soluble nickel salt), and water is prepared. Specifically, ferrous chloride tetrahydrate: 173.60 g and nickel chloride hexahydrate: 207.55 g were dissolved in pure water: 1200 mL to prepare a metal salt raw material solution.

(b) Preparation of reducing agent solution A reducing agent solution comprising sodium hydroxide (pH adjusting agent), hydrazine (reducing agent) and water was prepared. At this time, weighing was performed so that the amount of hydrazine relative to the total amount of magnetic metals (Fe and Ni) in the reaction solution prepared in the subsequent crystallization step became 19.4 in molar ratio. Moreover, it weighed so that the amount of sodium hydroxide with respect to the amount of magnetic metal (Fe and Ni) might become 4.96 in molar ratio. Specifically, sodium hydroxide: 346 g was dissolved in pure water: 850 mL to prepare a sodium hydroxide solution, and 60% by mass of hydrazine hydrate: 2828 g was added to the sodium hydroxide solution to prepare a reducing agent solution. In addition, when adding and mixing the reducing agent solution to the metal salt raw material solution, the reducing agent solution was used after being heated to a liquid temperature of 37°C so that the reaction initiation temperature was 55°C.

The obtained alloy powder is composed of spherical particles with relatively smooth surface. The particle size distribution is wide, with an average particle size of 0.22 μm.

Table 1 summarizes the production conditions of the alloy powders of Examples 1-15 and Comparative Examples 1-3 above.

[Table 1] Table 1 Production conditions of iron-nickel alloy powder Metal salt raw material solution Reducing agent solution (reducing agent + pH adjusting agent), or reducing agent solution (reducing agent) and pH adjusting solution (pH adjusting agent) Amine compound solution The reaction solution magnetic metal source Nucleating agent complexing agent Type of solution reducing agent pH regulator Amine compound Reaction initiation temperature (°C) Reaction holding temperature (°C) Fe salt/Ni salt/Co salt (molar ratio) metal species Blending amount (mole ppm) substance Blending amount (mole%) substance Blending amount (mol ratio) substance Blending amount (mol ratio) substance Blending amount (mole%) Example 1 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 PD 0.02 Sodium citrate 36.2 reducing agent solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Example 2 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/40/10 PD 0.02 Sodium citrate 36.2 Reducing agent solution & pH adjuster solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Example 3 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 PD 0.02 tartaric acid 20.0 reducing agent solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Example 4 FeSO ₄ /NiSO ₄ /CoSO ₄ =56/44/0 PD 0.20 Sodium citrate 31.8 reducing agent solution Hydrazine 6.41 NaOH 4.67 EDA 1.0 60 70 Example 5 [Before adding additional raw material solution] FeSO ₄ /NiSO ₄ /CoSO ₄ =56/44/0 [After adding additional raw material solution] FeSO ₄ /NiSO ₄ /CoSO ₄ =51/49/0 PD 0.20 (Note 2) Sodium citrate 31.8 (Note 2) reducing agent solution Hydrazine 4.41 (Note 3) NaOH 4.24 (Note 3) EDA 1.0 (Note 3) 59 70 Example 6 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 PD 0.02 Sodium citrate 36.2 reducing agent solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Example 7 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 PD 0.02 Sodium citrate 36.2 reducing agent solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Example 8 FeSO ₄ /NiSO ₄ /CoSO ₄ ＝65/35/0 PD 1.50 Sodium citrate 72.4 reducing agent solution Hydrazine 8.98 NaOH 7.07 EDA 1.0 71 80 Example 9 [Before adding additional raw material solution] FeSO ₄ /NiSO ₄ /CoSO ₄ =67.4/32.6/0 [After adding additional raw material solution] FeSO ₄ /NiSO ₄ /CoSO ₄ =65/35/0 PD 0.52 (Note 2) Sodium citrate 75.0 (Note 2) reducing agent solution Hydrazine 7.36 (Note 3) NaOH 7.07 (Note 3) EDA 1.0 (Note 3) 75 80 Example 10 [Before adding additional raw material liquid] FeSO ₄ /NiSO ₄ /CoSO ₄ =83.3/16.7/0 [After adding additional raw material liquid] FeSO ₄ /NiSO ₄ /CoSO ₄ =80/20/0 PD 0.42 (Note 2) Sodium citrate 75.4 (Note 2) reducing agent solution Hydrazine 9.02 (Note 3) NaOH 7.07 (Note 3) EDA 1.0 (Note 3) 71 80 Example 11 [Before adding additional raw material solution] FeSO ₄ /NiSO ₄ /CoSO ₄ =91.8/8.2/0 [After adding additional raw material solution] FeSO ₄ /NiSO ₄ /CoSO ₄ =90/10/0 PD 0.41 (Note 2) Sodium citrate 36.9 (Note 2) reducing agent solution Hydrazine 8.97 (Note 3) NaOH 8.13 (Note 3) EDA 1.0 (Note 3) 78 85 Example 12 FeSO ₄ /NiSO ₄ /CoSO ₄ =55/45/0 PD 0.30 Sodium citrate 54.3 reducing agent solution Hydrazine 4.85 NaOH 4.95 EDA 1.0 59 70 Example 13 FeSO ₄ /NiSO ₄ /CoSO ₄ = 80/10/10 PD 0.20 Sodium citrate 36.2 reducing agent solution Hydrazine 3.65 NaOH 7.07 EDA 1.0 70 85 Example 14 FeSO ₄ /NiSO ₄ /CoSO ₄ =70/10/20 PD 0.20 Sodium citrate 36.2 reducing agent solution Hydrazine 1.46 NaOH 7.07 EDA 1.0 67 85 Example 15 FeSO ₄ /NiSO ₄ /CoSO ₄ = 65/10/25 PD 0.20 Sodium citrate 36.2 reducing agent solution Hydrazine 1.47 NaOH 7.07 EDA 1.0 67 85 Comparative example 1 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 none none Sodium citrate 36.2 reducing agent solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Comparative example 2 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 PD 0.02 none none reducing agent solution Hydrazine 4.85 NaOH 4.96 EDA 1.0 55 70 Comparative example 3 FeCl ₂ /NiCl ₂ /CoCl ₂ = 50/50/0 none none none none reducing agent solution Hydrazine 19.4 NaOH 4.96 none - 55 70 Note 1) The blending amount of nucleating agent, complexing agent, pH adjuster, and amine compound (mole ppm, mole%, mole ratio) is the ratio to the total amount of magnetic metals (Fe, Ni, and Co) . Note 2) For the compounding amount of the crystallization reaction before adding the additional raw material solution. Note 3) For the compounding amount of crystallization reaction including addition of additional raw material solution.

(2) Evaluation of iron-nickel alloy powder For the iron-nickel alloy powders obtained in Examples 1 to 15 and Comparative Examples 1 to 3, various characteristics were evaluated as follows.

＜Composition Analysis＞ X-ray diffraction (XRD) measurement was performed using an X-ray diffraction device, and the presence or absence of alloy powder was confirmed from the obtained XRD data.

＜Analysis of metal impurities＞ Analyze the content of impurities. The amount of oxygen was measured by an inert gas melting method using an oxygen analyzer (manufactured by LECO Corporation, TC436), and the amount of carbon and sulfur was measured by a combustion method using a carbon-sulfur analyzer (manufactured by LECO Corporation, CS600). In addition, the amount of chlorine was measured using a fluorescent X-ray analyzer (manufactured by Spectris, Inc., Magix), and the amount of silicon and sodium was measured using an ICP emission spectrometer (manufactured by Agilent Technologies, Inc., 5100).

<Particle size (average particle size, coefficient of variation)> The alloy powder was observed with a scanning electron microscope (SEM; manufactured by JEOL Ltd., JSM-7100F) (magnification: 5000 to 80000 times). Image analysis is performed on the observation image (SEM image), and the average particle diameter and the standard deviation of the particle diameter obtained from the number average are calculated based on the result. Furthermore, the coefficient of variation (CV value) was calculated according to the following formula (14), and the particle size (average particle diameter, coefficient of variation) of the alloy powder was obtained.

CV value (%) = standard deviation of particle size / average particle size × 100 ・・・（14）

＜Particle composition analysis＞ Using a focused ion beam (FIB: Focused Ion Beam) device, the alloy powder embedded in resin was processed into a thin film with a thickness of about 100 nm. For the processed sample, a scanning transmission electron microscope (STEM; Hitachi High-Tech Co., Ltd. Manufacture, HD-2300A) to observe the profile of alloy particles. Observation was carried out under the condition of magnification: 100000-200000 times. Then, the composition distribution in the alloy particles was obtained by line analysis of an energy dispersive x-ray spectroscopy (EDS: Energy dispersive x-ray spectroscopy) device. At this time, the composition is calculated from the detection count value of characteristic X-rays (K-rays) of the measured elements.

＜Crystalline diameter＞ The alloy powder was analyzed by the X-ray diffraction (XRD) method, and the crystallite diameter was evaluated based on the Scherrer formula from the half maximum width of the X-ray diffraction peak of the (111) plane. The XRD measurement was carried out under the same conditions as the composition analysis. The crystallite diameter indicates the degree of crystallization, and the larger the crystallite diameter, the higher the crystallinity.

＜Powder Density＞ The powder compact density of the alloy powder was evaluated. Specifically, about 0.3 g of alloy powder was filled into a cylindrical hole (inner diameter: 5 mm) of the mold. Then, it was formed into a pellet shape with a diameter of 5 mm and a height of 3 to 4 mm by using a pressing machine at a pressure of 100 MPa. The mass and height of the obtained granules were measured at room temperature, and the compacted powder density was calculated.

＜Compact powder resistivity＞ The pressed powder resistivity of the alloy powder was measured using a powder resistance measuring system (manufactured by Mitsubishi Chemical Analytech, MCP-PD51), and electrical conductivity (insulation) was evaluated. Specifically, about 4 g of alloy powder was filled into the cylindrical sample chamber of the device, and a pressure of 64 MPa was applied using a press attached to the device to obtain the resistivity (unit: Ω·cm) of the compacted powder.

＜Magnetic properties (saturation magnetic flux density, coercive force)＞ The magnetic characteristics (saturation magnetic flux density (T: Tesla), coercive force (A/m)) of the alloy powder were evaluated by measuring with a vibrating sample magnetometer (VSM). Calculate the values of saturation magnetic flux density and coercive force from the B-H curve (hysteresis curve) obtained in the measurement. Furthermore, the alloy powder obtained in Comparative Example 2 cannot be applied to elements such as inductors due to its distorted shape, so the magnetic properties were not measured.

(3) Evaluation results Table 2 summarizes the evaluation results obtained about Examples 1-15 and Comparative Examples 1-3. In addition, the SEM images of the alloy powders obtained in Examples 1, 2, 10, 13, and 14 are shown in Figures 13, 14, 18, 20, and 21, and the alloy powders obtained in Example 6 The SEM images of the alloy powder are shown in Figure 15(a) and (b). Here, Fig. 15(a) is the SEM image of the alloy powder before the spiral jet crushing treatment, and Fig. 15(b) is the SEM image of the alloy powder after the spiral jet crushing treatment. Also, the STEM images and EDS line analysis results of the particle cross sections of the alloy powders obtained in Examples 8 and 9 are shown in Fig. 16(a), (b) and Fig. 17, respectively. Here, Figure 16(a) is the STEM image and EDS line analysis results of the particle profile of the alloy powder before high-temperature heat treatment, and Figure 16(b) is the STEM image and EDS line analysis of the particle profile of the alloy powder after high-temperature heat treatment Analyze the results. SEM images of the alloy powder obtained in Example 12 are shown in FIGS. 19( a ) and ( b ). Here, FIG. 19( a ) is an SEM image of the alloy powder before the insulating coating treatment, and FIG. 19( b ) is an SEM image of the alloy powder after the insulating coating treatment. Furthermore, SEM images of the respective alloy powders obtained in Comparative Examples 1 to 3 are shown in FIGS. 22 to 24 .

Example 1, Example 3, and Comparative Examples 1 to 3 are examples in which the reaction initiation temperature in the crystallization step is set at 55° C., and the reaction holding temperature is set at 70° C. to produce iron-nickel alloy powder. In Example 1 and Example 3 where very small amounts of specific nucleating agents and complexing agents were used, although the amount of hydrazine used as a reducing agent was small, the obtained alloy powders were also fine in average particle size, ranging from 0.40 to 0.41 μm, and the CV value is small, the particle size distribution is steep. Also, this alloy powder is spherical and has a smooth surface.

On the other hand, in Comparative Example 1 in which no nucleating agent was used, compared with Example 1 or Example 3, the average particle size of the obtained alloy powder was larger at 0.65 μm, making it difficult to miniaturize. Moreover, although it is spherical, it has large surface irregularities. In Comparative Example 2 where no complexing agent was used, although the average particle size of the obtained alloy powder was as fine as 0.26 μm, the CV value was larger and the particle size distribution was wider. In addition, the surface of the alloy powder has large unevenness and distorted shape. In Comparative Example 3, in which no nucleating agent and complexing agent were used but a large amount of reducing agent (hydrazine) was blended, the obtained alloy powder was spherical powder with a relatively smooth surface. The reason for this is considered to be that the reduction reaction proceeds strongly by blending a large amount of hydrazine. Also, the average particle size of the obtained alloy powder was as fine as 0.22 μm. However, the larger the CV value, the wider the particle size distribution.

Example 2 is an example of using a specific nucleating agent and complexing agent, setting the reaction initiation temperature in the crystallization step to 55° C., and setting the reaction holding temperature to 70° C. to produce iron-nickel-cobalt alloy powder. Although the amount of hydrazine used as a reducing agent is small, the average particle size of the obtained alloy powder is fine, about 0.3 μm, and the particle size distribution is steep. Also, the alloy powder has a spherical shape with a smooth surface. In addition, the saturation magnetization of the alloy powder is high.

Example 5 is to add and mix an additional raw material solution containing a water-soluble nickel salt to the reaction solution during the crystallization process to produce a nickel-rich surface composition containing 51 mol% of iron (Fe) and 49 mol% of nickel (Ni). An example of mole% iron-nickel alloy powder. Due to the nickel-rich surface composition, a dense oxide film is formed, thereby inhibiting the amount of oxidation on the particle surface. Therefore, the alloy powder not only becomes more stable in the air, but also has excellent magnetic properties such as saturation magnetic flux density.

Example 6 is an example of producing a spherical iron-nickel alloy powder with a very smooth surface by subjecting the crystallization powder obtained as a dry powder through the crystallization step and the recovery step to the spiral jet crushing treatment. In addition, Example 7 is an example of producing spherical iron-nickel alloy powder with a very smooth surface by performing high-pressure fluid collision crushing treatment on the slurry-like crystallization powder in the recovery step after the crystallization step. These alloy powders not only show smoothness, but also reduce aggregated particles. Therefore, the filling property is improved (the green compact density is increased). In addition, by reducing the aggregated particles, it is also expected to improve the eddy current loss generated through the particles.

In Example 8, the crystallization powder obtained by setting the reaction initiation temperature at 71°C and the reaction holding temperature at 80°C in the crystallization step was subjected to high-temperature heat treatment, and the composition uniformity in the produced particles was improved. An example of iron-nickel alloy powder with 65 mol% of iron (Fe) and 35 mol% of nickel (Ni). It can be seen from Figure 16(b) that the alloy powder has a uniform composition (65 mol% iron and 35 mol% nickel) in the particles, and it can be expected to be used not only as a soft magnetic material, but also as a low Thermal expansion material (Constant Fan Alloy).

Example 9 is to add and mix an additional raw material solution containing a water-soluble nickel salt to the reaction solution during crystallization to produce a nickel-rich surface composition containing 65 mol% of iron (Fe) and 35% of nickel (Ni). An example of mole% iron-nickel alloy powder. As can be seen from Fig. 17, a nickel-rich layer with a thickness of about 10 to 15 nm is formed on the particle surface, and a dense oxide film is formed due to the nickel-rich surface composition, thereby suppressing the amount of oxidation on the particle surface. Therefore, the alloy powder not only becomes more stable in the air, but also has excellent magnetic properties such as saturation magnetic flux density.

Example 10 and Example 11 were to add and mix the additional raw material solution containing water-soluble nickel salt to the reaction solution during the crystallization process, and to manufacture while promoting the reduction of iron ions (or iron hydroxide) that are not easily reduced. , to make the surface of the particles more nickel-rich, iron-nickel alloy powder containing 80 mol% of iron (Fe) and 20 mol% of nickel (Ni) and containing 90 mol% of iron (Fe) An example of iron-nickel alloy powder with mole% and nickel (Ni) 10 mole%. Even if the content of iron is as large as 80 mol% to 90 mol%, which is close to the composition of pure iron, and the amount of hydrazine used as a reducing agent is relatively small, the average particle size of 0.4 can be obtained without poor reduction. ~0.5 μm spherical alloy powder with a smooth surface and a steep particle size distribution. Also, the saturation magnetization of alloy powder is as high as that of pure iron powder (1.95 T ~ 2.0 T).

Compared with Examples 1-7, the compact density of the iron-nickel alloy powder obtained in Examples 8-11 is smaller. However, the iron-nickel alloy powders of Examples 1-7 (iron-nickel alloy powder comprising Fe56-50 mol% and Ni44-50 mol%, containing Fe50 mol%, Ni40 mol% and Co10 mol% % of iron-nickel-cobalt alloy powder) has a true specific gravity of 8.2 to 8.25. In contrast, the iron-nickel alloy powders of Example 8 and Example 9 (containing Fe65 mol% and Ni35 mol% iron- The true specific gravity of nickel alloy powder) is 8.1, and the true specific gravity of the iron-nickel alloy powder of embodiment 10 (comprising the iron-nickel alloy powder of Fe80 mol% and Ni20 mol%) is 8.0, and the iron-nickel alloy powder of embodiment 11- The true specific gravity of the nickel-based alloy powder (iron-nickel alloy powder containing 90 mol% Fe and 10 mol% Ni) is 7.9. Considering that the greater the content of iron, the smaller the true specific gravity of the iron-nickel alloy powder, it can be known The compressed powder density of each example is good.

Example 12 is to apply insulation coating treatment to the crystallization powder obtained through the crystallization step and recovery step as a dry powder, and to manufacture the iron-nickel alloy powder obtained by coating the particle surface with high-resistance silicon dioxide (SiO ₂ ). example. This alloy powder is expected to improve the eddy current loss generated between the particles because the insulation between the particles is greatly improved (the electrical resistivity of the powder compact is greatly increased).

Examples 13 to 15 contain water-soluble cobalt salts in addition to water-soluble iron salts and water-soluble nickel salts in the magnetic metal source to promote the reduction of iron ions (or iron hydroxide) that are not easily reduced, and produce cobalt containing An example of iron-nickel alloy powder with a ratio of 10 mol % to 25 mol % and a relatively high iron content of 65 mol % to 80 mol %. Specifically, iron-nickel-cobalt alloy powder containing Fe80 mol%, Ni10 mol% and Co10 mol%, iron-nickel-cobalt alloy powder containing Fe70 mol%, Ni10 mol% and Co20 mol%, are manufactured. Examples of cobalt alloy powder and iron-nickel-cobalt alloy powder containing Fe65 mol%, Ni10 mol%, and Co25 mol%. Even if the content of iron is as large as 65 mol% to 80 mol%, and thanks to the reduction reaction acceleration effect obtained by adding cobalt, the amount of hydrazine used as a reducing agent is very small, and it can be obtained without causing poor reduction. Spherical alloy powder. The average particle size of the alloy powder is fine, about 0.4 μm, and the particle size distribution is steep and the surface is smooth. Also, the saturation magnetization of alloy powder is as high as or higher than that of pure iron powder (1.95 T ~ 2.0 T).

Furthermore, although the true specific gravity of the iron-nickel alloy powders (iron-nickel-cobalt alloy powders) obtained in Examples 13 to 15 is estimated to be about 8.0 to 8.1, all compacted powders have good densities. The reason for this is considered to be that the reduction reaction acceleration effect obtained by adding cobalt completes the reduction reaction before the particles aggregate, and as a result, the aggregation of the particles during crystallization is suppressed. Also, it is considered to be related to the fact that another effect obtained by the addition of cobalt, that is, the promotion of spheroidization, improves the filling property of the particles.

[Table 2] Table 2 Properties of Iron-Nickel Alloy Powder Alloy composition Particle traits particle size Impurities (mass%) Crystallite diameter (nm) magnetic properties Compressed powder density (g/cm ³ ) shape Surface properties Average particle size (μm) CV value (%) Oxygen (O) Carbon (C) Chlorine (Cl) Sulfur (S) Sodium (Na) Silicon (Si) Saturation flux density (T) Coercive force (A/m) Example 1 Fe50-Ni50 spherical smooth 0.41 9.0 1.9 0.05 0.003 <0.01 0.13 <0.1 6.4 1.22 1194 3.70 Example 2 Fe50-Ni40-Co10 spherical smooth 0.33 19.9 1.6 0.04 0.002 <0.01 0.09 <0.1 9.2 1.42 1194 3.94 Example 3 Fe50-Ni50 spherical smooth 0.40 15.1 1.8 0.04 0.003 <0.01 0.13 <0.1 8.4 1.23 1194 3.75 Example 4 Fe56-Ni44 spherical smooth 0.38 11.7 2.0 0.04 <0.001 <0.01 0.20 <0.1 5.5 1.40 1600 3.70 Example 5 Fe51-Ni49 spherical smooth 0.40 13.5 1.2 0.04 <0.001 <0.01 0.19 <0.1 5.7 1.36 1660 3.73 Example 6 Fe50-Ni50 spherical very smooth 0.41 9.0 2.2 0.05 0.003 <0.01 0.13 <0.1 5.2 1.22 1194 4.05 Example 7 Fe50-Ni50 spherical very smooth 0.41 9.0 2.1 0.05 0.003 <0.01 0.13 <0.1 5.5 1.22 1194 3.96 Example 8 Fe65-Ni35 spherical smooth 0.27 14.1 1.9 0.05 <0.001 <0.01 0.16 <0.1 10.3 1.55 2590 3.49 Example 9 Fe65-Ni35 spherical smooth 0.39 11.5 1.3 0.04 <0.001 <0.01 0.15 <0.1 11.4 1.55 1790 3.64 Example 10 Fe80-Ni20 spherical smooth 0.48 10.4 1.2 0.02 <0.001 <0.01 0.09 <0.1 20.6 1.80 1220 3.61 Example 11 Fe90-Ni10 spherical smooth 0.38 9.9 0.9 0.01 <0.001 <0.01 0.02 <0.1 26.1 1.91 2662 3.55 Example 12 Fe55-Ni45 (insulation coating) spherical smooth 0.43 (0.39) 8.2 (8.1) - (2.0) - (0.05) <0.001 (<0.001) <0.01 (<0.01) 0.20 (0.20) 1.0 (<0.1) 4.8 (4.6) 1.33 (1.38) 1230 (1530) 3.52 (3.69) Example 13 Fe80-Ni10-Co10 spherical smooth 0.42 13.7 1.0 0.02 <0.001 <0.01 0.03 <0.1 19.6 2.00 1100 3.84 Example 14 Fe70-Ni10-Co20 spherical smooth 0.40 6.8 0.9 0.02 <0.001 <0.01 0.03 <0.1 18.3 2.06 1090 4.07 Example 15 Fe65-Ni10-Co25 spherical smooth 0.42 12.5 0.8 0.02 <0.001 <0.01 0.03 <0.1 16.4 2.10 1280 4.02 Comparative example 1 Fe50-Ni50 spherical Large bump 0.65 14.8 1.6 0.05 0.003 <0.01 0.13 <0.1 10.3 1.18 1353 3.72 Comparative example 2 Fe50-Ni50 distortion Large bump 0.26 40.5 2.3 0.02 0.002 <0.01 0.05 <0.1 11.7 - - 3.42 Comparative example 3 Fe50-Ni50 spherical relatively smooth 0.22 42.4 2.1 0.01 0.002 <0.01 0.06 <0.1 11.3 1.19 1194 3.58 Note 1) "-" means not measured. Note 2) The values in parentheses ( ) represent the values before insulation coating treatment.

10: Inductor 12,22,32,42,52: compressed powder core 14,24: Coil 16a, 16b: input and output terminals 20:Chip inductor 30: Reactor 34: 1st coil 36: Second coil 38: Connecting part 40: Stator 44,54: winding 50: rotor 56: output shaft

[FIG. 1] It is a process chart for demonstrating the manufacturing method of the alloy powder of this embodiment. [Fig. 2] is a process diagram for explaining the preparation of the reaction solution and the production of the alloy powder in the first embodiment. [ Fig. 3 ] is a process diagram for explaining the preparation of the reaction solution and the production of the alloy powder in the first embodiment. [ Fig. 4 ] is a process chart for explaining the preparation of the reaction solution and the production of the alloy powder in the second embodiment. [ Fig. 5 ] is a process chart for explaining the preparation of the reaction solution and the production of the alloy powder in the second embodiment. [ Fig. 6 ] is a process chart for explaining the preparation of the reaction solution and the production of the alloy powder in the third embodiment. [Fig. 7] shows an example of applying a powder compact containing alloy powder to an inductor (loop coil). [ Fig. 8 ] shows an example of applying a powder compact containing alloy powder to a chip inductor. [ Fig. 9 ] shows an example of applying a powder compact containing alloy powder to a reactor. [ Fig. 10 ] shows an example of applying a powder compact containing alloy powder to a stator of a rotating machine (motor) or a generator. [ Fig. 11 ] shows an example of applying a powder compact containing alloy powder to a rotor of a rotating machine (motor) or a generator. [ Fig. 12 ] is a graph showing the transition of the liquid temperature in the reaction tank in the crystallization step of Example 1. [ Fig. 13 ] is an SEM image of the alloy powder obtained in Example 1. [ Fig. 14 ] is an SEM image of the alloy powder obtained in Example 2. [ Fig. 15 ] is an SEM image of the alloy powder obtained in Example 6 (before and after spiral jet crushing treatment). [Fig. 16] STEM images and EDS line analysis results of the alloy powder (before and after high temperature heat treatment) obtained in Example 8. [ Fig. 17 ] is a STEM image of a particle section of the alloy powder obtained in Example 9, and an EDS line analysis result. [ Fig. 18 ] is an SEM image of the alloy powder obtained in Example 10. [ Fig. 19 ] is an SEM image of the alloy powder obtained in Example 12 (before and after insulation coating treatment). [ Fig. 20 ] is an SEM image of the alloy powder obtained in Example 13. [ Fig. 21 ] is an SEM image of the alloy powder obtained in Example 14. [ Fig. 22 ] is an SEM image of the alloy powder obtained in Comparative Example 1. [ Fig. 23 ] is an SEM image of the alloy powder obtained in Comparative Example 2. [ Fig. 24 ] is an SEM image of the alloy powder obtained in Comparative Example 3.

Claims (40)

A method for producing iron (Fe)-nickel (Ni) alloy powder, the iron (Fe)-nickel (Ni) alloy powder at least contains iron (Fe) and nickel (Ni) as magnetic metals, the method includes the following steps : preparation step, which prepares a magnetic metal source, a nucleating agent, a complexing agent, a reducing agent, and a pH regulator as starting materials; In the process, the crystallization powder comprising the above-mentioned magnetic metal is crystallized by a reduction reaction; and the recovery step recovers the above-mentioned crystallization powder from the above-mentioned reaction solution; and the above-mentioned magnetic metal source includes a water-soluble iron salt and a water-soluble nickel salt, the above-mentioned composition The nucleating agent is a water-soluble salt of a metal that is biased towards the noble metal side compared to nickel. The above-mentioned complexing agent is at least one selected from the group consisting of hydroxycarboxylic acid, salt of hydroxycarboxylic acid, and derivatives of hydroxycarboxylic acid. The above-mentioned reducing agent is hydrazine (N ₂ H ₄ ), and the aforementioned pH regulator is alkali metal hydroxide. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 1, wherein the above-mentioned water-soluble iron salt is selected from ferrous chloride (FeCl ₂ ), ferrous sulfate (FeSO ₄ ), and nitric acid At least one of the group consisting of ferrous iron (Fe(NO ₃ ) ₂ ). The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 1 or 2, wherein the above-mentioned water-soluble nickel salt is selected from nickel chloride (NiCl ₂ ), nickel sulfate (NiSO ₄ ), and nitric acid At least one of the group consisting of nickel (Ni(NO ₃ ) ₂ ). The method for producing iron (Fe)-nickel (Ni) alloy powder according to Claim 1 or 2, wherein the nucleating agent is at least one selected from the group consisting of copper salts, palladium salts, and platinum salts. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 1 or 2, wherein the complexing agent is selected from tartaric acid ((CH(OH)COOH) ₂ ) and citric acid (C(OH) (CH ₂ COOH) ₂ COOH) at least one hydroxycarboxylic acid. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 1 or 2, wherein the pH regulator is at least one selected from sodium hydroxide (NaOH) and potassium hydroxide (KOH). The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 1 or 2, wherein the magnetic metal further contains cobalt (Co), The aforementioned magnetic metal source further includes a water-soluble cobalt salt. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 7, wherein, in the above-mentioned magnetic metal, the content ratio of iron (Fe) is not less than 60 mol % and not more than 85 mol %, and cobalt The content ratio of (Co) is not less than 10 mol % and not more than 30 mol %, In the above-mentioned magnetic metal source, the content ratio of the water-soluble iron salt is not less than 60 mol% and not more than 85 mol%, and the content ratio of the water-soluble cobalt salt is not less than 10 mol% and not more than 30 mol%. Such as the production method of iron (Fe)-nickel (Ni) alloy powder according to claim 7, wherein the above-mentioned water-soluble cobalt salt is selected from cobalt chloride (CoCl ₂ ), cobalt sulfate (CoSO ₄ ), and cobalt nitrate ( At least one of the group consisting of Co(NO ₃ ) ₂ ). The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 1 or 2, wherein the above-mentioned starting material further includes the following amine compound, and the amine compound contains two or more primary amine groups in the molecule ( -NH ₂ ), one primary amino group (-NH ₂ ) and one or more secondary amino groups (-NH-), or two or more secondary amino groups (-NH-). The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 10, wherein the amine compound is at least one of alkylene amines and alkylene amine derivatives. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 11, wherein the above-mentioned alkylene amine and/or alkylene amine derivatives have at least the nitrogen atom of the amine group in the molecule through the carbon number The structure represented by the following (A) that is bonded together by a carbon chain of 2,

. Such as the production method of iron (Fe)-nickel (Ni) alloy powder according to claim 10, wherein the above-mentioned amine compound is selected from ethylenediamine (H ₂ NC ₂ H ₄ NH ₂ ), diethylenetriamine ( H ₂ NC ₂ H ₄ NHC ₂ H ₄ NH ₂ ), triethylenetetramine (H ₂ N(C ₂ H ₄ NH) ₂ C ₂ H ₄ NH ₂ ), tetraethylenepentamine (H ₂ N (C ₂ H ₄ NH) ₃ C ₂ H ₄ NH ₂ ), pentaethylenehexamine (H ₂ N(C ₂ H ₄ NH) ₄ C ₂ H ₄ NH ₂ ), and propylenediamine (CH ₃ CH (NH ₂ )CH ₂ NH ₂ ), at least one alkylene amine from the group consisting of, and/or tris(2-aminoethyl)amine (N(C ₂ H ₄ NH ₂ ) ₃ ), N-(2-aminoethyl)ethanolamine (H ₂ NC ₂ H ₄ NHC ₂ H ₄ OH), N-(2-aminoethyl)propanolamine (H ₂ NC ₂ H ₄ NHC ₃ H ₆ OH ), 2,3-diaminopropionic acid (H ₂ NCH ₂ CH(NH)COOH), ethylenediamine-N,N'-diacetic acid (HOOCCH ₂ NHC ₂ H ₄ NHCH ₂ COOH), and 1,2 - at least one alkylene amine derivative from the group consisting of cyclohexanediamine (H ₂ NC ₆ H ₁₀ NH ₂ ). The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 10, wherein the blending amount of the amine compound is not less than 0.01 mol % and not more than 5.00 mol % relative to the total amount of the above-mentioned magnetic metals. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 1 or 2, wherein, when preparing the reaction solution in the above-mentioned crystallization step, prepare a metal salt raw material solution obtained by dissolving the above-mentioned magnetic metal source, the above-mentioned nucleating agent, and the above-mentioned complexing agent in water, A reducing agent solution obtained by dissolving the above reducing agent in water, and A pH adjusting solution obtained by dissolving the above pH adjusting agent in water, The metal salt raw material solution and the pH adjustment solution are mixed to form a mixed solution, and the mixed solution is mixed with the reducing agent solution. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 15, wherein, when preparing the above-mentioned reaction solution, the above-mentioned pH adjustment solution and the above-mentioned reducing agent solution are sequentially added to the above-mentioned metal salt raw material solution to mix. The method for producing iron (Fe)-nickel (Ni) alloy powder according to Claim 15, wherein the time required for mixing the above-mentioned mixed solution and the above-mentioned reducing agent solution is set to 1 second to 180 seconds. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 1 or 2, wherein, when preparing the reaction solution in the above-mentioned crystallization step, prepare a metal salt raw material solution obtained by dissolving the above-mentioned magnetic metal source, the above-mentioned nucleating agent, and the above-mentioned complexing agent in water, and A reducing agent solution obtained by dissolving the above reducing agent and the above pH adjusting agent in water, The above metal salt raw material solution is mixed with the above reducing agent solution. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 18, wherein, when preparing the above-mentioned reaction solution, the above-mentioned reducing agent solution is added to the above-mentioned metal salt raw material solution, or vice versa Add the above-mentioned metal salt raw material solution to and mix. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 18, wherein the time required for mixing the metal salt raw material solution and the reducing agent solution is set to 1 second to 180 seconds. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 1 or 2, wherein, in the above-mentioned crystallization step, before the completion of the reduction reaction, the above-mentioned water-soluble nickel is further added to the above-mentioned reaction solution An additional raw material solution obtained by dissolving at least one of the salt and the above-mentioned water-soluble cobalt salt in water is mixed. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 15, which is blended into at least one of the above-mentioned metal salt raw material solution, the above-mentioned reducing agent solution, the above-mentioned pH adjustment solution, and the reaction solution Amine compounds. The method for producing iron (Fe)-nickel (Ni) alloy powder according to Claim 1 or 2, wherein the temperature of the reaction solution (reaction initiation temperature) at the start of crystallization of the crystallization powder is 40°C or higher and 90°C Below, and the temperature (reaction holding temperature) of the reaction solution held during the crystallization after the start of the crystallization is 60°C or more and 99°C or less. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 1 or 2, which further includes a crushing step, which is for the crystallization powder after the recovery step or the crystallization during the recovery step The powder is subjected to crushing treatment using collision energy, and the aggregated particles contained in the crystallized powder are crushed. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 24, which uses dry disintegration or wet disintegration to disintegrate the crystallization powder after the recovery step, or wet disintegration Disintegration Disintegrate the crystallization powder in the recovery step. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 25, wherein the above-mentioned dry disintegration is spiral jet disintegration. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 25, wherein the wet crushing is high-pressure fluid collision crushing. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in item 1 or 2, which further includes a high temperature heat treatment step, the high temperature heat treatment step is for the crystallization powder after the recovery step or the crystallization during the recovery step Powder, heat treatment over 150°C and below 400°C in an inactive environment, reducing environment, or vacuum environment, thereby improving the composition uniformity of iron (Fe)-nickel (Ni) alloy powder particles . The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 1 or 2, which further includes an insulating coating step, the insulating coating step is to apply insulating coating to the crystallization powder obtained through the recovery step Cloth treatment forms an insulating coating made of metal oxides on the particle surface of the crystallization powder, thereby improving the insulation between the particles. The method for producing iron (Fe)-nickel (Ni) alloy powder according to claim 29, wherein, in the above insulating coating step, the crystallized powder is dispersed in a mixed solvent containing water and an organic solvent, and then the metal The alkoxide is added and mixed into the above mixed solvent to prepare a slurry. In the above slurry, the metal alkoxide is hydrolyzed and dehydration polycondensed to form an insulating coating composed of metal oxide on the particle surface of the crystallization powder. , and then recover the crystallized powder with the insulating coating formed from the slurry. The method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in item 30, wherein the above-mentioned metal alkoxide is made of silane oxide (alkyl silicate) as the main component, and the above-mentioned metal oxide is made of dioxide Silicon (SiO ₂ ) is used as a main component. A method for producing iron (Fe)-nickel (Ni) alloy powder as claimed in claim 30, wherein the above-mentioned metal alkoxide is hydrolyzed in the presence of an alkali catalyst (alkali catalyst). An iron (Fe)-nickel (Ni) alloy powder produced by the method for producing iron (Fe)-nickel (Ni) alloy powder in any one of Claims 1 to 32. An alloy powder, which is an iron (Fe)-nickel (Ni) alloy powder containing at least iron (Fe) and nickel (Ni) as a magnetic metal, and has an average particle size of 0.10 μm or more and 0.60 μm or less, depending on the particle size The coefficient of variation (CV value) obtained from the average particle size and standard deviation in the distribution according to the following formula (1) is 25% or less, CV value (%) = standard deviation of particle size / average particle size × 100 ···(1). The alloy powder according to claim 34, further comprising cobalt (Co) as the magnetic metal. Such as the alloy powder of claim 34 or 35, wherein the amount of iron (Fe) is not less than 10 mol% and not more than 95 mol%, the amount of nickel (Ni) is not less than 5 mol% and not more than 90 mol%, and cobalt (Co ) amount is not less than 0 mol% and not more than 40 mol%. As the alloy powder of claim 34 or 35, the crystallite diameter is 30 nm or less. For example, the alloy powder of claim 34 or 35 has a saturation magnetic flux density of 1 T (Tesla) or more, and a coercive force of 2000 A/m or less. A compressed powder body or sheet comprising the alloy powder according to any one of claims 33 to 38. An inductor, a reactor, a choke coil, a noise filter, a transformer, a rotating machine, a generator, or a radio wave absorber, which includes the pressed powder and/or sheet of claim 39.

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