JP4433800B2 - Oxidation-resistant rare earth magnet powder and method for producing the same - Google Patents

Oxidation-resistant rare earth magnet powder and method for producing the same Download PDF

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JP4433800B2
JP4433800B2 JP2004003883A JP2004003883A JP4433800B2 JP 4433800 B2 JP4433800 B2 JP 4433800B2 JP 2004003883 A JP2004003883 A JP 2004003883A JP 2004003883 A JP2004003883 A JP 2004003883A JP 4433800 B2 JP4433800 B2 JP 4433800B2
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吉村  公志
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Proterial Ltd
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Description

本発明は、耐酸化性に優れるとともに高い磁気特性を示す希土類系ボンド磁石を製造するために有用な、耐酸化性希土類系磁石粉末およびその製造方法に関する。   The present invention relates to an oxidation-resistant rare earth magnet powder useful for producing a rare earth-based bonded magnet having excellent oxidation resistance and high magnetic properties, and a method for producing the same.

Nd−Fe−B系磁石粉末に代表されるR−Fe−B系磁石粉末などの希土類系磁石粉末を、バインダとして熱可塑性樹脂や熱硬化性樹脂などを用いて所定形状に成形することで製造される希土類系ボンド磁石は、樹脂バインダを含有しているために希土類系焼結磁石に比較すれば磁気特性が低くなるものの、フェライト磁石などに比べればなお十分に高い磁気特性を有しており、また、複雑形状や薄肉形状の磁石やラジアル異方性磁石を容易に得ることができるといった希土類系焼結磁石にはない特徴を持っている。従って、希土類系ボンド磁石は、特にスピンドルモータやステッピングモータなどの小型モータに多く用いられ、近年、その需要が増加している。
希土類系磁石粉末は高い磁気特性を有するが、RやFeが組成の大半を占めることから腐食や酸化を起しやすいという問題がある。そのため、希土類系ボンド磁石の製造においては、まず、希土類系磁石粉末を、溶解もしくは溶融(軟化)させた樹脂バインダと混合して磁石粉末の表面が樹脂バインダで被覆されたコンパウンドと呼ばれる粉末顆粒状原料を調製した後、このコンパウンドを射出成形や圧縮成形や押出成形し、用いる樹脂バインダが熱硬化性樹脂である場合にはさらに加熱して樹脂バインダを硬化させることで所定形状に成形して製品化される。しかしながら、このようにして製品化された希土類系ボンド磁石であっても、その表面に希土類系磁石粉末が露出していると、わずかな酸やアルカリや水分などの存在によって磁石粉末が腐食して錆が発生したり、100℃程度の大気中でも酸化が進行したりするので、例えば部品組み込み後に磁気特性の劣化やばらつきを招くことがある。また、樹脂バインダとして汎用されているエポキシ樹脂やナイロン樹脂などは水分や酸素の透過性を有する。従って、これらの樹脂を樹脂バインダに用いた希土類系ボンド磁石においては、樹脂を透過した水分や酸素で希土類系磁石粉末が腐食したり酸化したりする可能性があることを否定できない。さらに、希土類系磁石粉末が腐食や酸化を起しやすいことに鑑みれば、射出成形を行う場合には混練成形時の温度条件に配慮する必要があるし、圧縮成形を行う場合には成形後の硬化処理を不活性ガス雰囲気中や真空中で行う必要がある。
Manufactured by molding rare earth magnet powder such as R-Fe-B magnet powder represented by Nd-Fe-B magnet powder into a predetermined shape using thermoplastic resin or thermosetting resin as binder The rare-earth bonded magnets contain a resin binder and thus have lower magnetic properties than rare-earth sintered magnets, but still have sufficiently high magnetic properties compared to ferrite magnets. In addition, it has characteristics not found in rare-earth sintered magnets, such as the ability to easily obtain complex or thin-walled magnets and radial anisotropic magnets. Therefore, rare earth-based bonded magnets are often used particularly for small motors such as spindle motors and stepping motors, and the demand for them is increasing in recent years.
Rare earth magnet powders have high magnetic properties, but R and Fe occupy most of the composition, so that there is a problem that corrosion and oxidation are likely to occur. Therefore, in the production of rare-earth bonded magnets, first, a rare-earth magnet powder is mixed with a melted or melted (softened) resin binder, and the surface of the magnet powder is a powder granule called a compound coated with a resin binder. After preparing the raw material, this compound is injection-molded, compression-molded or extruded, and if the resin binder used is a thermosetting resin, it is further heated to cure the resin binder and molded into a predetermined shape. It becomes. However, even in the rare-earth bonded magnets manufactured in this way, if the rare-earth magnet powder is exposed on the surface, the magnet powder corrodes due to the presence of slight acid, alkali, moisture, etc. Since rust is generated or oxidation proceeds even in the atmosphere of about 100 ° C., for example, deterioration or variation in magnetic characteristics may be caused after assembly of the parts. In addition, epoxy resins and nylon resins that are widely used as resin binders have moisture and oxygen permeability. Therefore, in rare earth bond magnets using these resins as resin binders, it cannot be denied that the rare earth magnet powder may be corroded or oxidized by moisture or oxygen permeated through the resin. Furthermore, in view of the fact that rare earth magnet powders are susceptible to corrosion and oxidation, it is necessary to consider the temperature conditions during kneading when performing injection molding, and after molding when performing compression molding. It is necessary to perform the curing process in an inert gas atmosphere or in a vacuum.

以上のような問題を解消すべく、例えば、下記の特許文献1において、希土類系磁石粉末の表面に、リン酸塩の被覆処理を施し、リン酸塩被膜で表面被覆された希土類系磁石粉末を用いて所定形状に成形することによる酸化劣化を防止した希土類系ボンド磁石の製造方法が提案されている。
特開昭64−11304号公報
In order to solve the above problems, for example, in Patent Document 1 below, the surface of a rare earth magnet powder is subjected to a phosphate coating treatment, and a rare earth magnet powder surface-coated with a phosphate coating is obtained. There has been proposed a method for manufacturing a rare earth-based bonded magnet that prevents oxidation deterioration due to use and molding into a predetermined shape.
JP-A 64-11304

上記の特許文献1に記載された方法は、比較的低コストで高効率に希土類系磁石粉末に耐酸化性を付与することができることから、耐酸化性に優れた希土類系ボンド磁石を製造することができる方法として注目に値するものである。しかしながら、リン酸塩被膜は、リン酸塩被膜処理液成分と磁石粉末成分とが磁石粉末表面において化学反応することにより形成されるものであるため、その反応過程において、処理液中に磁石粉末の構成成分であるRやFeが溶出してしまうことで磁石粉末の表面付近(表面から深さ0.1μm程度)が変質して磁石粉末の磁気特性が劣化するという問題がある。また、このような磁石粉末を用いて所定形状に成形した希土類系ボンド磁石は、酸化による磁気特性の経時変化が大きいという問題がある。この現象は、ボンド磁石の成形時、磁石粉末の流れ性不足に起因して成形圧力により磁石粉末が割れたりし、酸化しやすい粒子破面が露出することなどによると推察される。これらの問題は、昨今における希土類系ボンド磁石に要求される高性能化の観点からは無視できない問題であり、早期に解決すべきものである。
そこで本発明は、耐酸化性に優れるとともに高い磁気特性を示す希土類系ボンド磁石を製造するために有用な、耐酸化性希土類系磁石粉末およびその製造方法を提供することを目的とする。
Since the method described in Patent Document 1 can impart oxidation resistance to a rare earth magnet powder at a relatively low cost and high efficiency, a rare earth bond magnet having excellent oxidation resistance can be produced. It is worth noting as a method that can. However, the phosphate coating is formed by a chemical reaction between the phosphate coating treatment liquid component and the magnet powder component on the surface of the magnet powder. As a result of the dissolution of the constituent components R and Fe, there is a problem in that the vicinity of the surface of the magnet powder (depth of about 0.1 μm from the surface) is altered to deteriorate the magnetic properties of the magnet powder. Moreover, the rare earth-based bonded magnet formed into a predetermined shape using such magnet powder has a problem that a change with time in magnetic characteristics due to oxidation is large. This phenomenon is presumed to be due to the fact that when the bonded magnet is molded, the magnet powder is cracked by the molding pressure due to the insufficient flowability of the magnet powder, and a particle fracture surface that is easily oxidized is exposed. These problems cannot be ignored from the viewpoint of high performance required for rare earth bonded magnets in recent years, and should be solved at an early stage.
Accordingly, an object of the present invention is to provide an oxidation-resistant rare earth magnet powder and a method for producing the same, which are useful for producing a rare earth bonded magnet having excellent oxidation resistance and high magnetic properties.

上記の技術背景に基づいてなされた本発明の耐酸化性希土類系磁石粉末は、請求項1記載の通り、平均粒径(長径)が0.01μm〜0.5μmである有機顔料を主たる構成成分とする被着層を表面に有してなることを特徴とする
た、請求項記載の耐酸化性希土類系磁石粉末は、請求項記載の耐酸化性希土類系磁石粉末において、有機顔料がインダンスレン系顔料またはフタロシアニン系顔料であることを特徴とする
た、請求項記載の耐酸化性希土類系磁石粉末は、請求項1または2記載の耐酸化性希土類系磁石粉末において、希土類系磁石粉末の平均粒径(長径)が200μm以下であることを特徴とする。
また、請求項記載の耐酸化性希土類系磁石粉末は、請求項記載の耐酸化性希土類系磁石粉末において、希土類系磁石粉末がHDDR磁石粉末であることを特徴とする。
また、本発明の平均粒径(長径)が0.01μm〜0.5μmである有機顔料を主たる構成成分とする被着層を表面に有してなる耐酸化性希土類系磁石粉末の製造方法は、請求項記載の通り、希土類系磁石粉末と平均粒径(長径)が0.01μm〜0.5μmである有機顔料含有処理液を混合した後、顔料含有処理液が表面に付着した希土類系磁石粉末を乾燥することを特徴とする。
また、請求項記載の製造方法は、請求項記載の製造方法において、希土類系磁石粉末と顔料含有処理液を混合した後、濾過を行って顔料含有処理液が表面に付着した希土類系磁石粉末を取得することを特徴とする。
また、請求項記載の製造方法は、請求項または記載の製造方法において、顔料含有処理液中における顔料の含有量が5重量%〜33重量%であることを特徴とする。
また、請求項記載の製造方法は、請求項乃至のいずれかに記載の製造方法において、顔料含有処理液が有機分散媒を含有してなることを特徴とする。
また、本発明の希土類系ボンド磁石用コンパウンドは、請求項記載の通り、請求項1記載の耐酸化性希土類系磁石粉末と樹脂バインダとからなることを特徴とする。
また、本発明の希土類系ボンド磁石は、請求項10記載の通り、請求項記載の希土類系ボンド磁石用コンパウンドを用いて所定形状に成形されてなることを特徴とする。


The oxidation-resistant rare earth magnet powder of the present invention made on the basis of the above technical background is mainly composed of an organic pigment having an average particle diameter (major axis) of 0.01 μm to 0.5 μm as described in claim 1. It is characterized by having on the surface an adhesion layer .
Also, oxidation resistant rare earth magnet powder of claim 2, in oxidation resistance rare earth magnet powder according to claim 1, wherein the organic pigment is a indanthrene pigments or phthalocyanine pigments .
Also, oxidation resistant rare earth magnet powder according to claim 3, wherein, in the oxidation resistance rare earth magnet powder according to claim 1 or 2, wherein, the average particle size of the rare earth-based magnet powder (major axis) is 200μm or less It is characterized by.
The oxidation-resistant rare earth magnet powder according to claim 4 is characterized in that in the oxidation-resistant rare earth magnet powder according to claim 3 , the rare earth magnet powder is HDDR magnet powder.
In addition, a method for producing an oxidation-resistant rare earth magnet powder having an adherent layer mainly comprising an organic pigment having an average particle diameter (major axis) of 0.01 μm to 0.5 μm according to the present invention is provided. As described in claim 5 , after mixing the rare earth-based magnet powder and the organic pigment- containing treatment liquid having an average particle diameter (major axis) of 0.01 μm to 0.5 μm , the rare earth-based material in which the pigment-containing treatment liquid is adhered to the surface The magnet powder is dried.
Further, the manufacturing method according to claim 6 is the manufacturing method according to claim 5 , wherein the rare earth-based magnet in which the rare earth-based magnet powder and the pigment-containing processing liquid are mixed and then filtered to adhere the pigment-containing processing liquid to the surface. It is characterized by obtaining powder.
The process according to claim 7, wherein, in the manufacturing method according to claim 5, wherein the content of the pigment in the pigment-containing treating solution is 5 wt% to 33 wt%.
The manufacturing method according to claim 8 is characterized in that, in the manufacturing method according to any of claims 5 to 7 , the pigment-containing treatment liquid contains an organic dispersion medium.
Moreover, the compound for rare earth based bonded magnets of the present invention comprises the oxidation resistant rare earth based magnetic powder according to claim 1 and a resin binder as described in claim 9 .
Moreover, the rare earth-based bonded magnet of the present invention is characterized in that, as described in claim 10 , the rare-earth bonded magnet compound according to claim 9 is molded into a predetermined shape.


本発明によれば、耐酸化性に優れるとともに高い磁気特性を示す希土類系ボンド磁石を製造するために有用な、耐酸化性希土類系磁石粉末およびその製造方法が提供される。   According to the present invention, there are provided an oxidation-resistant rare earth-based magnet powder and a method for producing the same, which are useful for producing a rare-earth bonded magnet having excellent oxidation resistance and high magnetic properties.

本発明の耐酸化性希土類系磁石粉末は、例えば、希土類系磁石粉末と顔料含有処理液を混合した後、顔料含有処理液が表面に付着した希土類系磁石粉末を乾燥することにより製造することができる。   The oxidation-resistant rare earth magnet powder of the present invention can be produced, for example, by mixing a rare earth magnet powder and a pigment-containing treatment liquid, and then drying the rare earth magnet powder having the pigment-containing treatment liquid attached to the surface. it can.

顔料含有処理液の調製方法としては、例えば、アンモニアなどでpHを6.5〜9.0に調整した弱アルカリ性水に顔料を分散させる方法が挙げられる。処理液のpHを6.5〜9.0に調整するのは、処理液による希土類系磁石粉末の腐食を防止するためである。処理液の粘度は、良好な取扱性を確保するといった観点から、2cP〜50cPが望ましい。なお、顔料含有処理液は、エチルアルコールやイソプロピルアルコールなどの有機溶媒に顔料を分散させたものであってもよい。   Examples of the method for preparing the pigment-containing treatment liquid include a method of dispersing the pigment in weakly alkaline water whose pH is adjusted to 6.5 to 9.0 with ammonia or the like. The reason why the pH of the treatment liquid is adjusted to 6.5 to 9.0 is to prevent corrosion of the rare earth magnet powder by the treatment liquid. The viscosity of the treatment liquid is preferably 2 cP to 50 cP from the viewpoint of ensuring good handleability. Note that the pigment-containing treatment liquid may be obtained by dispersing a pigment in an organic solvent such as ethyl alcohol or isopropyl alcohol.

顔料としては、有機顔料と無機顔料のいずれの顔料も用いることができる。有機顔料としては、インダンスレン系顔料やフタロシアニン系顔料の他、アゾ系、キナクリドン系、アントラキノン系、ジオキサンジン系、インジゴ系、チオインジゴ系、ペリノン系、ペリレン系、イソインドレン系、アゾメチンアゾ系、ジケトピロロピロール系の顔料などが挙げられる。顔料として有機顔料を用いた場合、有機顔料を主たる構成成分とする被着層を表面に有してなる希土類系磁石粉末は、樹脂バインダとからなる希土類系ボンド磁石用コンパウンドに適度の粘弾性と優れた流動性を付与するとともに、被着層を構成する有機顔料が圧縮成形時に受ける応力を吸収して緩和するので磁石粉末の破砕が起こって新生破面が生成するといったことが起きにくくなる点において都合がよい。また、有機顔料の種類によっては、ボンド磁石に高抵抗性を付与することができることが期待される。中でも、インダンスレン系顔料やフタロシアニン系顔料は、耐食性や耐熱性に優れるので、これらは好適な有機顔料であるといえる。
無機顔料としては、カーボンブラック、二酸化チタン、酸化鉄、酸化クロム、酸化亜鉛、アルミナ、硫化亜鉛、タルク、マイカ、炭酸カルシウムなどが挙げられる。顔料として無機顔料を用いた場合、希土類系磁石粉末の表面に形成された無機顔料を主たる構成成分とする被着層は、酸素や水蒸気などの非透過性に優れることから、磁石粉末にとりわけ優れた耐酸化性を付与することができる点において都合がよい。好適な無機顔料としては、カーボンブラックが挙げられる。
As the pigment, any of an organic pigment and an inorganic pigment can be used. Organic pigments include indanthrene pigments and phthalocyanine pigments, as well as azo, quinacridone, anthraquinone, dioxazine, indigo, thioindigo, perinone, perylene, isoindylene, azomethine azo, and diketo Examples include pyrrolopyrrole pigments. When an organic pigment is used as the pigment, the rare earth magnet powder having an adhesion layer containing the organic pigment as a main component on the surface is suitable for a rare earth bond magnet compound composed of a resin binder. In addition to providing excellent fluidity, the organic pigment constituting the adherent layer absorbs and relaxes the stress received during compression molding, so that it is difficult for the magnetic powder to break up and generate a new fracture surface Is convenient. In addition, depending on the type of organic pigment, it is expected that high resistance can be imparted to the bonded magnet. Among them, indanthrene pigments and phthalocyanine pigments are excellent organic pigments because they are excellent in corrosion resistance and heat resistance.
Examples of inorganic pigments include carbon black, titanium dioxide, iron oxide, chromium oxide, zinc oxide, alumina, zinc sulfide, talc, mica and calcium carbonate. When an inorganic pigment is used as the pigment, the adherent layer mainly composed of the inorganic pigment formed on the surface of the rare earth magnet powder is particularly excellent in magnet powder because it is excellent in impermeability of oxygen, water vapor, and the like. This is advantageous in that it can provide oxidation resistance. A suitable inorganic pigment includes carbon black.

顔料の平均粒径(長径)は、顔料含有処理液中における顔料の均一分散性を確保するといった観点から、0.01μm〜0.5μmが望ましい。平均粒径が0.01μm未満であると、その製造が困難であるとともに処理液中で凝集しやすくなって取扱性に劣る一方、平均粒径が0.5μmを超えると、処理液中における比重が大きくなってしまって沈降してしまったりする恐れがある。   The average particle diameter (major diameter) of the pigment is preferably 0.01 μm to 0.5 μm from the viewpoint of ensuring uniform dispersibility of the pigment in the pigment-containing treatment liquid. If the average particle size is less than 0.01 μm, it is difficult to produce and is easy to agglomerate in the treatment liquid, resulting in poor handling. On the other hand, if the average particle size exceeds 0.5 μm, the specific gravity in the treatment liquid May become large and sink.

処理液中における顔料の含有量は、5重量%〜33重量%が望ましい。含有量が5重量%未満であると、十分量の顔料からなる被着層が希土類系磁石粉末の表面に形成されず、優れた耐酸化性を磁石粉末に付与することができなくなる恐れがある一方、含有量が33重量%を超えると、処理液中で顔料が凝集や沈降してしまい、その分散性が悪化する恐れがあるからである。なお、処理液中における顔料の含有量は、より望ましくは10重量%〜30重量%である。   The content of the pigment in the treatment liquid is desirably 5% by weight to 33% by weight. If the content is less than 5% by weight, a sufficient amount of a coating layer made of pigment may not be formed on the surface of the rare earth magnet powder, and it may not be possible to impart excellent oxidation resistance to the magnet powder. On the other hand, if the content exceeds 33% by weight, the pigment aggregates or settles in the treatment liquid, and the dispersibility may be deteriorated. In addition, content of the pigment in a process liquid is 10 to 30 weight% more desirably.

顔料含有処理液には有機分散媒を添加することが望ましい。有機分散媒は、処理液中での顔料の凝集や沈降を抑制する目的で使用されるものである。有機分散媒としては、アニオン性分散媒(脂肪族系多価カルボン酸、ポリエーテルポリエステルカルボン酸塩、高分子ポリエステル酸ポリアミン塩、高分子量ポリカルボン酸長鎖アミン塩など)、非イオン性分散媒(ポリオキシエチレンアルキルエーテルやソルビタンエステルなどのカルボン酸塩やスルフォン酸塩やアンモニウム塩など)、高分子分散媒(水溶性エポキシのカルボン酸塩やスルフォン酸塩やアンモニウム塩など、スチレン−アクリル酸共重合物、ニカワなど)が、上記の目的の観点から、また、顔料との親和性やコストの観点などから好適に用いられる。   It is desirable to add an organic dispersion medium to the pigment-containing treatment liquid. The organic dispersion medium is used for the purpose of suppressing aggregation and sedimentation of the pigment in the treatment liquid. Examples of organic dispersion media include anionic dispersion media (aliphatic polycarboxylic acids, polyether polyester carboxylates, polymer polyester acid polyamine salts, high molecular weight polycarboxylic acid long chain amine salts, etc.), nonionic dispersion media (Carboxylic acid salts such as polyoxyethylene alkyl ethers and sorbitan esters, sulfonic acid salts and ammonium salts), polymer dispersion media (such as water-soluble epoxy carboxylates, sulfonic acid salts and ammonium salts). Polymers, glues, etc.) are preferably used from the viewpoints of the above-mentioned purpose and from the viewpoints of affinity with the pigment and cost.

処理液中への有機分散媒の添加量は、9重量%〜24重量%が望ましい。添加量が9重量%未満であると、顔料の分散性が低下する恐れがある一方、24重量%を超えると、処理液の粘性が高くなりすぎて取扱性に劣る恐れがあるからである。   The amount of the organic dispersion medium added to the treatment liquid is desirably 9% by weight to 24% by weight. If the added amount is less than 9% by weight, the dispersibility of the pigment may be lowered. On the other hand, if the added amount exceeds 24% by weight, the viscosity of the treatment liquid becomes too high and the handleability may be deteriorated.

耐酸化性希土類系磁石粉末は、例えば、以上のようにして調製された顔料含有処理液に、希土類系磁石粉末を浸漬して混合攪拌した後、顔料含有処理液が表面に付着した希土類系磁石粉末を濾取してからこれを乾燥して製造することができる。顔料含有処理液に希土類系磁石粉末を浸漬して混合攪拌する時間は、希土類系磁石粉末量などにも依存するが、概ね1分〜20分である。顔料含有処理液が表面に付着した希土類系磁石粉末を濾取する際、減圧濾過や加圧濾過を行えば、磁石粉末の表面に顔料をより強固に吸着せしめることができる。磁気特性の劣化を招くことなく希土類系磁石粉末に耐酸化性を付与するためには、乾燥は、自然乾燥または不活性ガス(窒素ガスやアルゴンガスなど)雰囲気中や真空中80℃〜120℃加熱乾燥が望ましい。加熱乾燥を採用する場合の乾燥時間は、希土類系磁石粉末量などにも依存するが、概ね20分〜2時間である。濾取した顔料含有処理液が表面に付着した希土類系磁石粉末が凝集塊となっている場合には予め解砕してから乾燥することが望ましい。なお、顔料含有処理液が表面に付着した希土類系磁石粉末の取得は、希土類系磁石粉末に顔料含有処理液を噴霧することで行ってもよい。   The oxidation-resistant rare earth magnet powder is, for example, a rare earth magnet in which the rare earth magnet powder is immersed in the pigment-containing treatment liquid prepared as described above, mixed and stirred, and then the pigment-containing treatment liquid adheres to the surface. It can be produced by filtering the powder and then drying it. The time for which the rare earth magnet powder is immersed in the pigment-containing treatment liquid and mixed and stirred is approximately 1 to 20 minutes, although it depends on the amount of the rare earth magnet powder. When the rare earth magnet powder with the pigment-containing treatment liquid attached to the surface is filtered, the pigment can be more firmly adsorbed to the surface of the magnet powder by performing vacuum filtration or pressure filtration. In order to impart oxidation resistance to the rare earth magnet powder without deteriorating the magnetic properties, the drying is performed in a natural dry or inert gas (nitrogen gas, argon gas, etc.) atmosphere or in a vacuum of 80 ° C. to 120 ° C. Heat drying is desirable. The drying time in the case of employing heat drying is generally 20 minutes to 2 hours, although it depends on the amount of rare earth magnet powder. When the rare earth-based magnet powder having the pigment-containing treatment liquid collected by filtration attached to the surface is agglomerated, it is desirable to disintegrate and dry in advance. The rare earth magnet powder having the pigment containing treatment liquid adhered to the surface may be obtained by spraying the pigment containing treatment liquid onto the rare earth magnet powder.

以上のようにして希土類系磁石粉末の表面に形成された顔料を主たる構成成分とする被着層は、優れた耐酸化性を磁石粉末に付与するものであるが、リン酸塩被膜のように、磁石粉末成分が関与する化学反応に基づいて形成されたものではなく、ナノメートルオーダーの顔料微粒子が分子間力で磁石粉末の表面に吸着して形成されたものであるので、その形成過程において、処理液中に磁石粉末の構成成分であるRやFeが溶出してしまうことで磁石粉末の表面付近が変質して磁石粉末の磁気特性が劣化するといった問題などがない。従って、本発明の耐酸化性希土類系磁石粉末を用いれば、耐酸化性に優れるとともに高い磁気特性を示す希土類系ボンド磁石を製造することができる。
さらに、本発明の耐酸化性希土類系磁石粉末を用いて製造された希土類系ボンド磁石が耐酸化性に優れるのは、磁石粉末が耐酸化性に優れることによるだけでなく、通常、ボンド磁石の成形時においては、磁石粉末の流れ性不足に起因して成形圧力により磁石粉末が割れて酸化しやすい粒子破面が生じたりすることがあるが、本発明の耐酸化性希土類系磁石粉末を用いた場合には、磁石粉末の表面に形成された被着層を構成する顔料粒子が、ボンド磁石の成形時における磁石粉末の流れ性を改善する潤滑作用を発揮することで、成形圧力により磁石粉末が割れて酸化しやすい粒子破面が生じたりすることが抑制されていることにもよると推測される。
また、希土類系ボンド磁石の成形方法として、圧縮成形方法や、圧縮成形と圧延成形を組み合わせた成形方法(例えば、F.Yamashita, Applications of Rare-Earth Magnets to the Small motor industry, pp.100-111, Proceedings of the seventeenth international workshop, Rare Earth Magnets and Their Applications, August 18-22, 2002, Newark, Delaware, USA, Edited by G.C. Hadjipanayis and M.J.Bonder, Rinton Pressを参照)などを採用した場合、通常、製造されたボンド磁石の表面には無数の空孔部が存在するが、本発明の耐酸化性希土類系磁石粉末を用いて製造された希土類系ボンド磁石においては、そのような空孔部を、磁石粉末の表面に形成された被着層を構成する顔料粒子が封孔するという効果があり、このことも本発明の耐酸化性希土類系磁石粉末を用いて製造された希土類系ボンド磁石が耐酸化性に優れることに寄与していると考えられる。
As described above, the adherent layer mainly composed of the pigment formed on the surface of the rare earth-based magnet powder imparts excellent oxidation resistance to the magnet powder. It is not formed based on a chemical reaction involving the magnet powder component, but is formed by adsorbing nanometer-order pigment fine particles on the surface of the magnet powder with intermolecular force. In addition, there is no problem that the vicinity of the surface of the magnet powder is altered and the magnetic properties of the magnet powder are deteriorated due to elution of R and Fe, which are constituents of the magnet powder, in the treatment liquid. Therefore, if the oxidation-resistant rare earth magnet powder of the present invention is used, a rare earth bond magnet having excellent oxidation resistance and high magnetic properties can be produced.
Furthermore, the reason why the rare earth-based bonded magnet manufactured using the oxidation-resistant rare earth magnet powder of the present invention is excellent in oxidation resistance is not only due to the fact that the magnet powder is excellent in oxidation resistance. At the time of molding, the magnet powder may be cracked by the molding pressure due to insufficient flowability of the magnet powder, resulting in a particle fracture surface that is likely to be oxidized. The oxidation-resistant rare earth magnet powder of the present invention is used. In this case, the pigment particles constituting the adherent layer formed on the surface of the magnet powder exhibit a lubricating action that improves the flowability of the magnet powder during the molding of the bonded magnet, so that the magnet powder is produced by the molding pressure. It is presumed that this is also due to the suppression of the occurrence of particle fracture surfaces that are susceptible to cracking and oxidation.
In addition, as a method for forming a rare earth-based bonded magnet, a compression molding method or a molding method combining compression molding and rolling molding (for example, F. Yamashita, Applications of Rare-Earth Magnets to the Small motor industry, pp. 100-111). , Proceedings of the seventeenth international workshop, Rare Earth Magnets and Their Applications, August 18-22, 2002, Newark, Delaware, USA, Edited by GC Hadjipanayis and MJBonder, Rinton Press) There are innumerable voids on the surface of the bonded magnet, but in the rare earth bond magnet manufactured using the oxidation-resistant rare earth magnet powder of the present invention, such voids are formed in the magnet powder. There is an effect that the pigment particles constituting the adherent layer formed on the surface of the material are sealed, and this is also the effect of the rare earth bond magnet manufactured by using the oxidation resistant rare earth magnet powder of the present invention. To be superior to It is considered to be given.

上記の特許文献1に記載されているリン酸塩被膜処理液を用いた場合に起る、希土類系磁石粉末の表面付近が変質するといった現象は、とりわけ、平均粒径(長径)が小さい(例えば200μm以下)磁石粉末に対して磁気特性の劣化を顕著に引き起すことになる。しかしながら、本発明によれば、平均粒径(長径)が小さい希土類系磁石粉末、例えば、平均粒径が80μm〜100μm程度の、希土類系磁石合金を水素中で加熱して水素を吸蔵させた後、脱水素処理し、次いで冷却することによって得られる磁気的異方性のHDDR(Hydrogenation-Disproportionation-Desorption-Recombination)磁石粉末(特公平6−82575号公報参照)などに対しても、磁気特性の劣化を引き起すことなく優れた耐酸化性を付与することができる。なお、希土類系磁石粉末は、予め、自体公知の方法によって酸洗や脱脂や洗浄などの前処理が施されたものであってもよい。   The phenomenon that occurs when the phosphate coating treatment liquid described in Patent Document 1 described above is altered near the surface of the rare earth magnet powder has a particularly small average particle diameter (major diameter) (for example, (200 μm or less) The magnetic properties of the magnetic powder are significantly deteriorated. However, according to the present invention, after a rare earth magnet powder having a small average particle diameter (major axis), for example, a rare earth magnet alloy having an average particle diameter of about 80 μm to 100 μm is heated in hydrogen and occluded by hydrogen. , Magnetic anisotropy HDDR (Hydrogenation-Disproportionation-Desorption-Recombination) magnetic powder (see Japanese Patent Publication No. 6-82575) obtained by dehydrogenation and then cooling. Excellent oxidation resistance can be imparted without causing deterioration. The rare earth magnet powder may have been subjected to pretreatment such as pickling, degreasing and washing in advance by a method known per se.

以下、本発明を実施例によってさらに詳細に説明するが、本発明はこれに限定して解釈されるものではない。なお、以下の実施例は、高周波溶解によって組成:Nd12.8原子%,Dy1.0原子%,B6.3原子%,Co14.8原子%,Ga0.5原子%,Zr0.09原子%,残部Feの鋳隗を作製し、アルゴンガス雰囲気中で1100℃×24時間焼鈍したものを酸素濃度0.5%以下のアルゴンガス雰囲気中で粉砕して平均粒径100μmの粉砕粉としてからこれを0.15MPaの水素ガス加圧雰囲気中で870℃×3時間の水素化熱処理を行い、その後、減圧(1kPa)アルゴンガス流気中で850℃×1時間の脱水素処理を行ってから冷却して製造したHDDR磁石粉末(平均結晶粒径0.4μm)を用いて行った。   EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is limited to this and is not interpreted. In the following examples, the composition was obtained by high-frequency melting: Nd 12.8 atomic%, Dy 1.0 atomic%, B 6.3 atomic%, Co 14.8 atomic%, Ga 0.5 atomic%, Zr 0.09 atomic%, the balance An iron cast iron was prepared and annealed at 1100 ° C. for 24 hours in an argon gas atmosphere and pulverized in an argon gas atmosphere with an oxygen concentration of 0.5% or less to obtain a pulverized powder having an average particle size of 100 μm. The hydrogenation heat treatment is performed at 870 ° C. for 3 hours in a hydrogen gas pressurized atmosphere of 15 MPa, and then the dehydrogenation treatment is performed at 850 ° C. for 1 hour in a reduced pressure (1 kPa) argon gas stream, followed by cooling. This was carried out using the produced HDDR magnet powder (average crystal grain size 0.4 μm).

実施例A:
実験1:耐酸化性HDDR磁石粉末の製造
顔料として無機顔料であるカーボンブラック(平均粒径0.08μm)を17重量%と有機分散媒として水溶性エポキシのカルボン酸塩を15重量%含み、アンモニアでpHを7.2に調整して水性処理液(粘度10cP)を調製した。
50mlの処理液にHDDR磁石粉末50gを室温で3分間浸漬して混合攪拌した後、処理済磁石粉末を水流アスピレータを用いて30秒間減圧濾過を行って濾取し、その後、真空中100℃で1時間加熱乾燥した。得られた凝集塊を乳鉢で解砕することで、カーボンブラックを主たる構成成分とする被着層を表面に有してなる黒色の耐酸化性HDDR磁石粉末を製造した。
このようにして製造された耐酸化性HDDR磁石粉末1gに対し、大気中150℃で100時間加熱する加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。結果を表1に示す。
Example A:
Experiment 1: Production of oxidation-resistant HDDR magnet powder 17% by weight of carbon black (average particle size 0.08 μm) as an inorganic pigment and 15% by weight of water-soluble epoxy carboxylate as an organic dispersion medium, ammonia The pH was adjusted to 7.2 to prepare an aqueous treatment liquid (viscosity 10 cP).
After 50 g of HDDR magnetic powder was immersed in 50 ml of processing liquid at room temperature for 3 minutes and mixed and stirred, the processed magnetic powder was filtered under reduced pressure for 30 seconds using a water aspirator, and then filtered at 100 ° C. in vacuum. Heat-dried for 1 hour. The obtained agglomerates were crushed with a mortar to produce a black oxidation-resistant HDDR magnet powder having an adherent layer containing carbon black as a main component on the surface.
A heating test of heating at 150 ° C. in the atmosphere for 100 hours was performed on 1 g of the oxidation-resistant HDDR magnet powder thus produced, and the weight increase rate due to oxidation after the test before the test was measured. The results are shown in Table 1.

実験2:ボンド磁石の製造とその特性
エポキシ樹脂とフェノール系硬化剤を重量比率で100:3の割合でメチルエチルケトンに溶解して樹脂液を調製した。実験1で製造した耐酸化性HDDR磁石粉末と樹脂液を、耐酸化性HDDR磁石粉末と樹脂液の合計重量に対する樹脂液の重量の比率が3%となるように均一混合した後、メチルエチルケトンを常温で蒸発させて粉末顆粒状の希土類系ボンド磁石用コンパウンドを得た。得られた希土類系ボンド磁石用コンパウンドを、圧縮成形(100℃温間磁場中成形、Hex=0.96MA/m、0.6GPa)し、得られた成形体を150℃のアルゴンガス雰囲気中で1時間加熱してエポキシ樹脂を硬化させて、寸法が縦12.0mm×横7.6mm×高さ7.4mmで密度が5.9g/cm3のボンド磁石を製造した。
こうして製造されたボンド磁石に対し、大気中150℃で100時間加熱する加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。また、ボンド磁石に対して着磁を行った後、大気中100℃で500時間加熱する加熱試験と大気中150℃で100時間加熱する加熱試験を行い、それぞれの加熱試験について、試験前に対する試験後における磁束劣化率(不可逆減磁率)を測定した。さらに、大気中150℃で100時間加熱する加熱試験を行ったボンド磁石については再着磁を行い、加熱試験前に対する再着磁後における磁束劣化率(永久減磁率)を測定した。これらの結果を図1と図2と表2に示す。
Experiment 2: Production of bonded magnet and its characteristics An epoxy resin and a phenolic curing agent were dissolved in methyl ethyl ketone at a weight ratio of 100: 3 to prepare a resin solution. After uniformly mixing the oxidation-resistant HDDR magnet powder and the resin liquid produced in Experiment 1 so that the ratio of the weight of the resin liquid to the total weight of the oxidation-resistant HDDR magnet powder and the resin liquid is 3%, methyl ethyl ketone is added at room temperature. To obtain a powdery granule-based compound for rare earth bonded magnets. The obtained compound for rare earth-based bonded magnet was compression-molded (molded in a warm magnetic field at 100 ° C., Hex = 0.96 MA / m, 0.6 GPa), and the resulting molded product was placed in an argon gas atmosphere at 150 ° C. The epoxy resin was cured by heating for 1 hour to produce a bonded magnet having dimensions of 12.0 mm in length, 7.6 mm in width, 7.4 mm in height, and a density of 5.9 g / cm 3 .
The thus-produced bonded magnet was subjected to a heating test in which it was heated at 150 ° C. in the atmosphere for 100 hours, and the weight increase rate due to oxidation after the test before the test was measured. In addition, after magnetizing the bonded magnet, a heating test in which heating is performed at 100 ° C. in air for 500 hours and a heating test in which heating is performed at 150 ° C. in air for 100 hours are performed. The magnetic flux deterioration rate (irreversible demagnetization factor) was measured later. Furthermore, rebonding was performed on the bonded magnet that was subjected to a heating test at 150 ° C. for 100 hours in the atmosphere, and the magnetic flux deterioration rate (permanent demagnetization factor) after remagnetization before the heating test was measured. These results are shown in FIGS.

実施例B:
実験1:耐酸化性HDDR磁石粉末の製造
顔料として有機顔料であるインダンスレン(平均粒径0.06μm)を17重量%と有機分散媒として水溶性エポキシのカルボン酸塩を15重量%含み、アンモニアでpHを7.2に調整して水性処理液(粘度15cP)を調製した。
この処理液を用いて実施例Aの実験1と同様にしてインダンスレンを主たる構成成分とする被着層を表面に有してなる藍色の耐酸化性HDDR磁石粉末を製造した。こうして製造された耐酸化性HDDR磁石粉末に対し、実施例Aの実験1と同様の加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。結果を表1に示す。
Example B:
Experiment 1: Production of oxidation-resistant HDDR magnet powder 17% by weight of indanthrene (average particle size 0.06 μm) as an organic pigment as a pigment and 15% by weight of a water-soluble epoxy carboxylate as an organic dispersion medium, An aqueous treatment liquid (viscosity 15 cP) was prepared by adjusting the pH to 7.2 with ammonia.
Using this treatment solution, an indigo-colored oxidation-resistant HDDR magnet powder having an adherent layer containing indanthrene as a main constituent was produced in the same manner as in Experiment 1 of Example A. The oxidation resistance HDDR magnet powder thus produced was subjected to the same heating test as in Experiment 1 of Example A, and the weight increase rate due to oxidation after the test before the test was measured. The results are shown in Table 1.

実験2:ボンド磁石の製造とその特性
実験1で製造した耐酸化性HDDR磁石粉末を用いて実施例Aの実験2と同様にしてボンド磁石を製造した。こうして製造されたボンド磁石に対し、実施例Aの実験2と同様の各種試験を行った。これらの結果を図1と図2と表2に示す。
Experiment 2: Manufacture of Bond Magnet and Its Characteristics A bond magnet was manufactured in the same manner as in Experiment 2 of Example A using the oxidation-resistant HDDR magnet powder manufactured in Experiment 1. Various tests similar to Experiment 2 of Example A were performed on the manufactured bonded magnet. These results are shown in FIGS.

実施例C:
実験1:耐酸化性HDDR磁石粉末の製造
顔料として有機顔料である銅フタロシアニン(平均粒径0.06μm)を17重量%と有機分散媒として水溶性エポキシのカルボン酸塩を15重量%含み、アンモニアでpHを7.2に調整して水性処理液(粘度17cP)を調製した。
この処理液を用いて実施例Aの実験1と同様にして銅フタロシアニンを主たる構成成分とする被着層を表面に有してなる藍色の耐酸化性HDDR磁石粉末を製造した。こうして製造された耐酸化性HDDR磁石粉末に対し、実施例Aの実験1と同様の加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。結果を表1に示す。
Example C:
Experiment 1: Production of oxidation resistant HDDR magnet powder 17% by weight of copper phthalocyanine (average particle size 0.06 μm) as an organic pigment and 15% by weight of a water-soluble epoxy carboxylate as an organic dispersion medium, ammonia The pH was adjusted to 7.2 to prepare an aqueous treatment liquid (viscosity 17 cP).
Using this treatment solution, an indigo-colored oxidation-resistant HDDR magnet powder having an adhesion layer containing copper phthalocyanine as a main constituent on the surface was produced in the same manner as in Experiment 1 of Example A. The oxidation resistance HDDR magnet powder thus produced was subjected to the same heating test as in Experiment 1 of Example A, and the weight increase rate due to oxidation after the test before the test was measured. The results are shown in Table 1.

実験2:ボンド磁石の製造とその特性
実験1で製造した耐酸化性HDDR磁石粉末を用いて実施例Aの実験2と同様にしてボンド磁石を製造した。こうして製造されたボンド磁石に対し、実施例Aの実験2と同様の各種試験を行った。これらの結果を図1と図2と表2に示す。
Experiment 2: Manufacture of Bond Magnet and Its Characteristics A bond magnet was manufactured in the same manner as in Experiment 2 of Example A using the oxidation-resistant HDDR magnet powder manufactured in Experiment 1. Various tests similar to Experiment 2 of Example A were performed on the manufactured bonded magnet. These results are shown in FIGS.

実施例D:
実験1:耐酸化性HDDR磁石粉末の製造
顔料として有機顔料であるインダンスレン(平均粒径0.06μm)を17重量%と有機分散媒としてアクリル重合物系高分子分散媒を15重量%含んだエチルアルコール処理液(粘度30cP)を調製した。
この処理液を用いて実施例Aの実験1と同様にしてインダンスレンを主たる構成成分とする被着層を表面に有してなる藍色の耐酸化性HDDR磁石粉末を製造した。こうして製造された耐酸化性HDDR磁石粉末に対し、実施例Aの実験1と同様の加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。結果を表1に示す。
Example D:
Experiment 1: Production of oxidation-resistant HDDR magnet powder 17% by weight of indanthrene (average particle size 0.06 μm) as an organic pigment as a pigment and 15% by weight of an acrylic polymer polymer dispersion medium as an organic dispersion medium An ethyl alcohol treatment solution (viscosity 30 cP) was prepared.
Using this treatment solution, an indigo-colored oxidation-resistant HDDR magnet powder having an adherent layer containing indanthrene as a main constituent was produced in the same manner as in Experiment 1 of Example A. The oxidation resistance HDDR magnet powder thus produced was subjected to the same heating test as in Experiment 1 of Example A, and the weight increase rate due to oxidation after the test before the test was measured. The results are shown in Table 1.

実験2:ボンド磁石の製造とその特性
実験1で製造した耐酸化性HDDR磁石粉末を用いて実施例Aの実験2と同様にしてボンド磁石を製造した。こうして製造されたボンド磁石に対し、実施例Aの実験2と同様の各種試験を行った。これらの結果を図1と図2と表2に示す。
Experiment 2: Manufacture of Bond Magnet and Its Characteristics A bond magnet was manufactured in the same manner as in Experiment 2 of Example A using the oxidation-resistant HDDR magnet powder manufactured in Experiment 1. Various tests similar to Experiment 2 of Example A were performed on the manufactured bonded magnet. These results are shown in FIGS.

実施例E:
実験1:耐酸化性HDDR磁石粉末の製造
顔料として無機顔料であるカーボンブラック(平均粒径0.08μm)を17重量%と有機分散媒としてアクリル重合物系高分子分散媒を15重量%含んだエチルアルコール処理液(粘度28cP)を調製した。
この処理液を用いて実施例Aの実験1と同様にしてカーボンブラックを主たる構成成分とする被着層を表面に有してなる黒色の耐酸化性HDDR磁石粉末を製造した。こうして製造された耐酸化性HDDR磁石粉末に対し、実施例Aの実験1と同様の加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。結果を表1に示す。
Example E:
Experiment 1: Production of oxidation-resistant HDDR magnet powder 17% by weight of an inorganic pigment, carbon black (average particle size 0.08 μm), and 15% by weight of an acrylic polymer-based polymer dispersion medium as an organic dispersion medium An ethyl alcohol treatment liquid (viscosity 28 cP) was prepared.
Using this treatment liquid, a black oxidation-resistant HDDR magnet powder having an adherent layer containing carbon black as a main component on the surface was produced in the same manner as in Experiment 1 of Example A. The oxidation resistance HDDR magnet powder thus produced was subjected to the same heating test as in Experiment 1 of Example A, and the weight increase rate due to oxidation after the test before the test was measured. The results are shown in Table 1.

実験2:ボンド磁石の製造とその特性
実験1で製造した耐酸化性HDDR磁石粉末を用いて実施例Aの実験2と同様にしてボンド磁石を製造した。こうして製造されたボンド磁石に対し、実施例Aの実験2と同様の各種試験を行った。これらの結果を図1と図2と表2に示す。
Experiment 2: Manufacture of Bond Magnet and Its Characteristics A bond magnet was manufactured in the same manner as in Experiment 2 of Example A using the oxidation-resistant HDDR magnet powder manufactured in Experiment 1. Various tests similar to Experiment 2 of Example A were performed on the manufactured bonded magnet. These results are shown in FIGS.

比較例:
何らの表面処理も行っていないHDDR磁石粉末に対し、実施例Aの実験1と同様の加熱試験を行い、試験前に対する試験後における酸化による重量増加率を測定した。結果を表1に示す。また、何らの表面処理も行っていないHDDR磁石粉末を用いて実施例Aの実験2と同様にしてボンド磁石を製造した。こうして製造されたボンド磁石に対し、実施例Aの実験2と同様の各種試験を行った。これらの結果を図1と図2と表2に示す。
Comparative example:
A heating test similar to Experiment 1 of Example A was performed on the HDDR magnet powder that had not been subjected to any surface treatment, and the rate of weight increase due to oxidation after the test before the test was measured. The results are shown in Table 1. Moreover, the bonded magnet was manufactured like the experiment 2 of Example A using the HDDR magnet powder which has not performed any surface treatment. Various tests similar to Experiment 2 of Example A were performed on the manufactured bonded magnet. These results are shown in FIGS.

Figure 0004433800
Figure 0004433800

Figure 0004433800
Figure 0004433800

表1から明らかなように、実施例A〜実施例Eにおいて製造された耐酸化性HDDR磁石粉末は、何らの表面処理も行っていないHDDR磁石粉末よりも酸化による重量増加率が遥かに少なく、これらの磁石粉末は耐酸化性に優れることがわかった。
また、図1と図2と表2から明らかなように、実施例A〜実施例Eにおけるボンド磁石は、比較例におけるボンド磁石よりも酸化による重量増加率も磁束劣化率も少なかった。実施例A〜実施例Eにおけるボンド磁石がこのような優れた特性を示すのは、優れた耐酸化性が付与されたHDDR磁石粉末を用いて所定形状に成形されていることに基づくものであるとともに、コンパウンド作製時や所定形状に成形する際の圧縮成形時や成形後においても、磁石粉末の割れなどによる表面損傷が抑制されていることで酸化が効果的に阻止されていることに基づくものである。また、これらのボンド磁石の表面を走査型電子顕微鏡にて観察すれば、その空孔部がボンド磁石の樹脂バインダで固着した顔料粒子で封孔されていることを確認することができる。このような効果もこれらのボンド磁石が耐酸化性に優れることに寄与していると考えられる。
As is apparent from Table 1, the oxidation-resistant HDDR magnet powder produced in Examples A to E has a much smaller weight increase rate due to oxidation than the HDDR magnet powder that has not been subjected to any surface treatment. These magnet powders were found to be excellent in oxidation resistance.
As is clear from FIGS. 1, 2, and Table 2, the bonded magnets in Examples A to E had a smaller weight increase rate due to oxidation and a magnetic flux deterioration rate than the bonded magnets in the comparative example. The reason why the bonded magnets in Examples A to E exhibit such excellent characteristics is based on being formed into a predetermined shape using HDDR magnet powder with excellent oxidation resistance. In addition, it is based on the fact that oxidation is effectively prevented by suppressing surface damage caused by cracking of the magnet powder, even during compression molding when molding a compound, molding into a predetermined shape, and after molding It is. Moreover, if the surface of these bonded magnets is observed with a scanning electron microscope, it can be confirmed that the pores are sealed with pigment particles fixed with a resin binder of the bonded magnet. It is considered that such an effect also contributes to the excellent resistance of these bonded magnets to oxidation.

本発明は、耐酸化性に優れるとともに高い磁気特性を示す希土類系ボンド磁石を製造するために有用な、耐酸化性希土類系磁石粉末およびその製造方法を提供することができる点において産業上の利用可能性を有する。   INDUSTRIAL APPLICABILITY The present invention is industrially applicable in that it can provide an oxidation-resistant rare earth magnet powder and a method for producing the same, which are useful for producing a rare earth bonded magnet having excellent oxidation resistance and high magnetic properties. Have potential.

実施例における、大気中100℃で500時間加熱する加熱試験による磁束劣化率(不可逆減磁率)の測定結果を示すグラフ。The graph which shows the measurement result of the magnetic flux deterioration rate (irreversible demagnetization factor) by the heating test heated at 100 degreeC in air | atmosphere for 500 hours in an Example. 同、大気中150℃で100時間加熱する加熱試験における測定結果を示すグラフ。The graph which shows the measurement result in the heating test which heats at 150 degreeC in air | atmosphere for 100 hours.

Claims (10)

平均粒径(長径)が0.01μm〜0.5μmである有機顔料を主たる構成成分とする被着層を表面に有してなることを特徴とする耐酸化性希土類系磁石粉末 An oxidation-resistant rare earth magnet powder characterized in that it has on its surface an adherent layer containing an organic pigment having an average particle diameter (major axis) of 0.01 μm to 0.5 μm as a main component . 有機顔料がインダンスレン系顔料またはフタロシアニン系顔料であることを特徴とする請求項記載の耐酸化性希土類系磁石粉末 Oxidation resistance rare earth magnet powder according to claim 1, wherein the organic pigment is a indanthrene pigments or phthalocyanine pigments. 希土類系磁石粉末の平均粒径(長径)が200μm以下であることを特徴とする請求項1または2記載の耐酸化性希土類系磁石粉末。 The oxidation-resistant rare earth magnet powder according to claim 1 or 2 , wherein the rare earth magnet powder has an average particle size (major axis) of 200 µm or less. 希土類系磁石粉末がHDDR磁石粉末であることを特徴とする請求項記載の耐酸化性希土類系磁石粉末。 4. The oxidation-resistant rare earth magnet powder according to claim 3 , wherein the rare earth magnet powder is an HDDR magnet powder. 希土類系磁石粉末と平均粒径(長径)が0.01μm〜0.5μmである有機顔料含有処理液を混合した後、顔料含有処理液が表面に付着した希土類系磁石粉末を乾燥することを特徴とする平均粒径(長径)が0.01μm〜0.5μmである有機顔料を主たる構成成分とする被着層を表面に有してなる耐酸化性希土類系磁石粉末の製造方法。 A rare earth magnet powder having an average particle size (major axis) of 0.01 μm to 0.5 μm mixed with an organic pigment- containing treatment liquid and then the rare earth magnet powder adhered to the surface is dried. A method for producing an oxidation-resistant rare earth magnet powder having an adherent layer having an organic pigment having an average particle diameter (major axis) of 0.01 μm to 0.5 μm as a main constituent. 希土類系磁石粉末と顔料含有処理液を混合した後、濾過を行って顔料含有処理液が表面に付着した希土類系磁石粉末を取得することを特徴とする請求項記載の製造方法。 6. The method according to claim 5 , wherein the rare earth magnet powder and the pigment-containing treatment liquid are mixed and then filtered to obtain the rare earth magnet powder having the pigment-containing treatment liquid attached to the surface. 顔料含有処理液中における顔料の含有量が5重量%〜33重量%であることを特徴とする請求項または記載の製造方法。 The production method according to claim 5 or 6 , wherein the pigment content in the pigment-containing treatment liquid is 5 wt% to 33 wt%. 顔料含有処理液が有機分散媒を含有してなることを特徴とする請求項乃至のいずれかに記載の製造方法。 The process according to any one of claims 5 to 7 pigment-containing treatment liquid is characterized by containing an organic dispersion medium. 請求項1記載の耐酸化性希土類系磁石粉末と樹脂バインダとからなることを特徴とする希土類系ボンド磁石用コンパウンド。   A compound for a rare earth-based bonded magnet comprising the oxidation-resistant rare earth based magnet powder according to claim 1 and a resin binder. 請求項記載の希土類系ボンド磁石用コンパウンドを用いて所定形状に成形されてなることを特徴とする希土類系ボンド磁石。 A rare earth-based bonded magnet, which is formed into a predetermined shape using the rare-earth bonded magnet compound according to claim 9 .
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