JPH05304020A - Ferrite core insulating material and its insulating method - Google Patents
Ferrite core insulating material and its insulating methodInfo
- Publication number
- JPH05304020A JPH05304020A JP4107485A JP10748592A JPH05304020A JP H05304020 A JPH05304020 A JP H05304020A JP 4107485 A JP4107485 A JP 4107485A JP 10748592 A JP10748592 A JP 10748592A JP H05304020 A JPH05304020 A JP H05304020A
- Authority
- JP
- Japan
- Prior art keywords
- ferrite core
- insulating
- compound
- iron
- forming
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Soft Magnetic Materials (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Abstract
(57)【要約】
【目的】 磁気特性を劣化させることなしに高周波にお
いてもフェライトの絶縁性を保つことができるフェライ
トコアの絶縁材及びそれを用いたフェライトコアの絶縁
方法を提供すること。
【構成】 フェライトコアの絶縁材は，フェライトコア
表面に絶縁皮膜を形成するための絶縁皮膜形成用組成物
であって，有機酸鉄の化合物とこれを溶解する有機溶剤
とを含む。この有機酸鉄の化合物は，硝酸鉄とジオール
をメトキシエタノール（エチレングリコール）に溶解
し，反応させ蒸留した硝酸鉄とジオールをメトキシエタ
ノール（エチレングリコール）に溶解し，反応させ蒸留
して有機酸鉄の化合物を生成する。フェライトコアは，
有機酸鉄の化合物からなる皮膜をフェライトコア表面に
形成し，加熱して，酸化鉄皮膜を形成することで，前記
フェライトコア表面が絶縁される。この酸化鉄皮膜を形
成させる際の熱処理温度は４００〜７００℃である。(57) [Abstract] [Purpose] To provide an insulating material of a ferrite core capable of maintaining the insulating property of the ferrite even at a high frequency without deteriorating the magnetic characteristics, and an insulating method of the ferrite core using the same. [Structure] The insulating material of the ferrite core is an insulating film forming composition for forming an insulating film on the surface of the ferrite core, and contains a compound of organic acid iron and an organic solvent that dissolves the compound. This organic acid iron compound is prepared by dissolving iron nitrate and diol in methoxyethanol (ethylene glycol) and reacting and distilling them. To produce a compound of. The ferrite core is
By forming a film made of a compound of organic acid iron on the surface of the ferrite core and heating it to form an iron oxide film, the surface of the ferrite core is insulated. The heat treatment temperature for forming this iron oxide film is 400 to 700 ° C.
Description
【０００１】[0001]
【産業上の利用分野】本発明は，高周波で使用するトラ
ンス用フェライトコア表面の絶縁方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of insulating the surface of a ferrite core for a transformer used at high frequencies.
【０００２】[0002]
【従来の技術】近年，電気製品の小型化にともないトラ
ンスコアの小型化が要求されており，巻線を少なくしコ
アの表面で他の部品とをつなぐリード線をコア表面で固
定する形のコアが多くなってきた。2. Description of the Related Art In recent years, miniaturization of transformer cores has been required along with miniaturization of electric products, and the number of windings has been reduced to fix lead wires connecting other components on the surface of the core on the surface of the core. The core is increasing.
【０００３】[0003]
【発明が解決しようとする課題】フェライトは一般に直
流比抵抗は〜３０００Ω-cm であるが，高周波を印加す
ると数１０Ω-cm 程度になってしまいそれ故漏電による
他の電子部品の損傷が問題となっていた。Ferrite generally has a DC specific resistance of up to 3,000 Ω-cm, but when a high frequency is applied, it becomes about several tens Ω-cm, which causes damage to other electronic components due to leakage current. Was becoming.
【０００４】そこで，本発明の技術的課題は，以上の問
題を解決し，磁気特性を劣化させることなしに高周波に
おいてもフェライトの絶縁性を保つことができるフェラ
イトコアの絶縁材及びそれを用いたフェライトコアの絶
縁方法を提供することにある。Therefore, the technical problem of the present invention is to solve the above problems and to use an insulating material of a ferrite core which can maintain the insulating property of ferrite even at a high frequency without deteriorating the magnetic characteristics, and the use thereof. It is to provide a method of insulating a ferrite core.
【０００５】[0005]
【課題を解決するための手段】前述のようにコア表面で
リード線を固定する場合には，フェライトコア表面を絶
縁処理することが必要である。本発明は，前述の課題を
解決するために，有機酸鉄の化合物をフェライトコアに
塗布し酸化鉄（例えばα−Ｆｅ2 Ｏ3 ）の皮膜を形成さ
せ絶縁性を高めるものである。In order to fix the lead wire on the core surface as described above, it is necessary to insulate the ferrite core surface. In order to solve the above-mentioned problems, the present invention is to apply a compound of organic acid iron to a ferrite core to form a film of iron oxide (for example, α-Fe 2 O 3 ) to enhance the insulating property.
【０００６】即ち，本発明によれば，フェライトコア表
面に絶縁皮膜を形成するための絶縁皮膜形成用組成物で
あって，有機酸鉄の化合物とこれを溶解する有機溶剤と
を含むことを特徴とするフェライトコアの絶縁材が得ら
れる。That is, according to the present invention, there is provided an insulating film forming composition for forming an insulating film on the surface of a ferrite core, which comprises an organic acid iron compound and an organic solvent which dissolves the compound. Insulating material for ferrite core is obtained.
【０００７】本発明の酸化鉄の皮膜を得る方法では，硝
酸鉄とジオールをメトキシエタノール（エチレングリコ
ール）に溶解し反応させ蒸留後，有機酸鉄を生成させ有
機溶媒に溶解しそれをフェライトコアに塗布した後，熱
処理し，Ｆｅ2 Ｏ3 の膜を形成することを特徴としてい
る。In the method for obtaining a film of iron oxide of the present invention, iron nitrate and diol are dissolved in methoxyethanol (ethylene glycol) and reacted to be distilled, and then organic acid iron is produced and dissolved in an organic solvent to form a ferrite core. After coating, heat treatment is performed to form a Fe 2 O 3 film.
【０００８】また，本発明では，前記酸化鉄皮膜を形成
させる際の熱処理は４００〜７００℃の温度であること
を特徴としている。Further, the present invention is characterized in that the heat treatment for forming the iron oxide film is performed at a temperature of 400 to 700 ° C.
【０００９】ここで，本発明において，皮膜形成のため
の熱処理温度を４００〜７００℃の温度範囲内に限定し
たのは，熱処理温度が４００℃より低いと膜がコア表面
に形成されないためにフェライトコアそのものに影響を
与えるため磁気特性は劣化し，一方，熱処理温度が７０
０℃より高いとフェライトコアの磁気特性が劣化してし
まうからである。この磁気特性の劣化原因は，今のとこ
ろ不明であるが，フェライトコアの粒界近傍にγ−Ｆｅ
2 Ｏ3 が現れ歪みを与えるためと考えられる。In the present invention, the heat treatment temperature for forming the film is limited within the temperature range of 400 to 700 ° C. because the film is not formed on the core surface when the heat treatment temperature is lower than 400 ° C. The magnetic properties are deteriorated because it affects the core itself, while the heat treatment temperature is 70
This is because the magnetic characteristics of the ferrite core deteriorate if the temperature is higher than 0 ° C. The cause of this deterioration of the magnetic properties is unknown at this point, but γ-Fe is present near the grain boundaries of the ferrite core.
It is considered that 2 O 3 appears and gives strain.
【００１０】また，本発明によれば，フェライトコア表
面に絶縁皮膜を形成するための絶縁材用原料を製造する
方法において，硝酸鉄とジオールをメトキシエタノール
（エチレングリコール）に溶解し，反応させ蒸留した硝
酸鉄とジオールをメトキシエタノール（エチレングリコ
ール）に溶解し，反応させ蒸留して有機酸鉄の化合物を
生成することを特徴とする絶縁材用原料の製造方法が得
られる。Further, according to the present invention, in a method for producing a raw material for an insulating material for forming an insulating film on the surface of a ferrite core, iron nitrate and diol are dissolved in methoxyethanol (ethylene glycol), reacted and distilled. A method for producing a raw material for an insulating material is obtained, which comprises dissolving the iron nitrate and the diol thus prepared in methoxyethanol (ethylene glycol), reacting them and distilling to produce a compound of organic acid iron.
【００１１】本発明のように，絶縁材用原料を製造する
ための鉄塩としては硝酸鉄以外でも同様の効果は得られ
ると思われるが，一般に鉄塩から酸化鉄を得る様なこの
種の反応には，硝酸鉄が用いられ手にいれ易いために，
本発明では，硝酸鉄を採用した。As in the present invention, it is considered that the same effect can be obtained as the iron salt for producing the raw material for the insulating material other than iron nitrate, but in general, this type of iron oxide from the iron salt is used. Because iron nitrate is used in the reaction and is easy to get,
In the present invention, iron nitrate is used.
【００１２】[0012]
【実施例】以下，本発明の実施例の説明をする。EXAMPLES Examples of the present invention will be described below.
【００１３】（実施例１）５３．０Ｆｅ2 Ｏ3 −３５．
０ＭｎＯ−１２．０ＺｎＯ（モル％）のフェライトコア
を通常の粉末冶金法で作製した後，絶縁皮膜を施した。
この絶縁皮膜は硝酸鉄と１．２−ドデカンジオールをメ
トキシエタノールに溶解し反応させ有機酸鉄を作製し有
機溶媒に溶解後，コア表面に塗布し温度３００〜８００
℃で熱処理することで形成した。次の表１に本発明の実
施例１により絶縁を施した試料の磁気特性及び周波数１
MHz の比抵抗と熱処理温度との関係を示す。比較のため
に絶縁皮膜を施す前のコアの磁気特性及び１MHz の比抵
抗もあわせて示す。ここで表１において，μは周波数１
０kHz の時の透磁率，Ｂ15，およびＨｃは直流印加磁場
１５Ｏｅの時の最大磁束密度および保磁力である。ま
た，表１においてＰB は周波数１MHz ，最大駆動磁束密
度５００Ｇのときのコアロス，ρは周波数１MHzの時の
比抵抗である。尚，３００℃では絶縁皮膜が形成されな
かった。(Example 1) 53.0Fe 2 O 3 -35.
A ferrite core of 0MnO-12.0ZnO (mol%) was produced by a usual powder metallurgy method, and then an insulating film was applied.
This insulating film is prepared by dissolving iron nitrate and 1.2-dodecanediol in methoxyethanol and reacting them to produce organic acid iron, dissolving it in an organic solvent, and coating it on the core surface at a temperature of 300-800.
It was formed by heat treatment at ℃. The following Table 1 shows the magnetic characteristics and frequency 1 of the sample insulated according to Example 1 of the present invention.
The relationship between the resistivity of MHz and the heat treatment temperature is shown. For comparison, the magnetic characteristics of the core before applying the insulating film and the specific resistance of 1 MHz are also shown. Here, in Table 1, μ is frequency 1
The magnetic permeability, B15, and Hc at 0 kHz are the maximum magnetic flux density and the coercive force when the direct current applied magnetic field is 15 Oe. Further, in Table 1, P B is the core loss when the frequency is 1 MHz and the maximum driving magnetic flux density is 500 G, and ρ is the specific resistance when the frequency is 1 MHz. An insulating film was not formed at 300 ° C.
【００１４】[0014]
【表１】 [Table 1]
【００１５】表１より明らかなように４００〜７００℃
の温度であれば磁気特性を劣化させずにフェライトコア
に絶縁皮膜を施すことができることがわかる。As is clear from Table 1, 400 to 700 ° C.
It is understood that at the temperature of, the insulating coating can be applied to the ferrite core without deteriorating the magnetic characteristics.
【００１６】（実施例２）５３．０Ｆｅ2 Ｏ3 −３５．
０ＭｎＯ−１２．０ＺｎＯ（モル％）のフェライトコア
を通常の粉末冶金法で作製した後，絶縁皮膜を施した。
絶縁皮膜は硝酸鉄および１，２−ドデカンジオール，
１，２−ペンタンジオール，１，２−ヘキサンジオール
の各種ジオールをそれぞれメトキシエタノールに溶解し
反応させて有機酸鉄を作製しベンゼンに溶解後，コア表
面に塗布し温度５００℃で熱処理することで形成した。
表２に本発明の実施例２により各種ジオールを用いて有
機酸鉄を作製し絶縁皮膜を施した試料の磁気特性及び周
波数１MHz の比抵抗と熱処理温度を示す。比較のために
絶縁皮膜を施す前のコアの磁気特性及び１MHz の比抵抗
もあわせて表２に示した。ここで表２においてμは周波
数１０kHz の時の透磁率，Ｂ15，およびＨｃは直流印加
磁場１５Ｏｅの時の最大磁束密度および保磁力である。
また，表２においてＰB は周波数１MHz ，最大駆動密度
５００Ｇのときのコアロス，ρは周波数１MHz の時の比
抵抗である。(Example 2) 53.0Fe 2 O 3 -35.
A ferrite core of 0MnO-12.0ZnO (mol%) was produced by a usual powder metallurgy method, and then an insulating film was applied.
The insulating film is iron nitrate and 1,2-dodecanediol,
Various diols such as 1,2-pentanediol and 1,2-hexanediol are dissolved in methoxyethanol and reacted to produce organic acid iron, which is dissolved in benzene and then applied on the core surface and heat-treated at a temperature of 500 ° C. Formed.
Table 2 shows the magnetic characteristics, the specific resistance at a frequency of 1 MHz, and the heat treatment temperature of a sample in which an organic acid iron was prepared using various diols and an insulating film was applied according to Example 2 of the present invention. For comparison, Table 2 also shows the magnetic characteristics of the core before applying the insulating film and the specific resistance of 1 MHz. In Table 2, μ is the magnetic permeability when the frequency is 10 kHz, B 15 and Hc are the maximum magnetic flux density and the coercive force when the DC applied magnetic field is 15 Oe.
In Table 2, P B is the core loss when the frequency is 1 MHz and the maximum driving density is 500 G, and ρ is the specific resistance when the frequency is 1 MHz.
【００１７】[0017]
【表２】 [Table 2]
【００１８】表２より明らかなように如何なるジオール
であっても磁気特性を劣化させずにフェライトコアに絶
縁皮膜を施すことができることがわかる。As is clear from Table 2, any diol can be used to form an insulating film on the ferrite core without deteriorating the magnetic properties.
【００１９】以上，本発明の実施例１及び２では一部の
ジオールについてのみ述べたが他のジオールを用いても
同様な効果が期待できる。Although only some diols have been described in Examples 1 and 2 of the present invention, similar effects can be expected by using other diols.
【００２０】[0020]
【発明の効果】以上述べたごとく，本発明によれば，フ
ェライトコア表面に磁気特性を劣化させることなしに絶
縁皮膜を施すことができるフェライトコアの絶縁材及び
それを用いたフェライトコアの絶縁方法を提供すること
ができる。As described above, according to the present invention, an insulating material for a ferrite core, which can form an insulating film on the surface of the ferrite core without deteriorating the magnetic characteristics, and a method for insulating a ferrite core using the same. Can be provided.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 山下 隆司 東京都千代田区内幸町一丁目１番６号 日 本電信電話株式会社内 (72)発明者 遠藤 久仁 東京都千代田区内幸町一丁目１番６号 日 本電信電話株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Yamashita 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Inhito Hisahi 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation
Claims (4)
るための絶縁皮膜形成用組成物であって，有機酸鉄の化
合物とこれを溶解する有機溶剤とを含むことを特徴とす
るフェライトコアの絶縁材。1. An insulating film-forming composition for forming an insulating film on the surface of a ferrite core, comprising the compound of organic acid iron and an organic solvent for dissolving the same, and insulating the ferrite core. Material.
るための絶縁材用原料を製造する方法において，硝酸鉄
とジオールをメトキシエタノール（エチレングリコー
ル）に溶解し，反応させ蒸留した硝酸鉄とジオールをメ
トキシエタノール（エチレングリコール）に溶解し，反
応させ蒸留して有機酸鉄の化合物を生成することを特徴
とする絶縁材用原料の製造方法。2. A method for producing a raw material for an insulating material for forming an insulating film on a surface of a ferrite core, wherein iron nitrate and diol are dissolved in methoxyethanol (ethylene glycol) and reacted to distill iron nitrate and diol. 1. A method for producing a raw material for an insulating material, which comprises dissolving in methoxyethanol (ethylene glycol), reacting it, and distilling to produce a compound of organic acid iron.
イトコア表面に形成し，加熱して，酸化鉄皮膜を形成し
て前記フェライトコア表面を絶縁することを特徴とする
フェライトコアの絶縁方法。3. A method for insulating a ferrite core, which comprises forming a film made of a compound of organic acid iron on the surface of the ferrite core and heating it to form an iron oxide film to insulate the surface of the ferrite core.
法において，前記酸化鉄皮膜を形成させる際の熱処理温
度は４００〜７００℃であることを特徴とするフェライ
トコアの絶縁方法。4. The method for insulating a ferrite core according to claim 3, wherein the heat treatment temperature for forming the iron oxide film is 400 to 700 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4107485A JPH05304020A (en) | 1992-04-27 | 1992-04-27 | Ferrite core insulating material and its insulating method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4107485A JPH05304020A (en) | 1992-04-27 | 1992-04-27 | Ferrite core insulating material and its insulating method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05304020A true JPH05304020A (en) | 1993-11-16 |
Family
ID=14460415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4107485A Withdrawn JPH05304020A (en) | 1992-04-27 | 1992-04-27 | Ferrite core insulating material and its insulating method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05304020A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101745637A (en) * | 2010-02-11 | 2010-06-23 | 柴秀兰 | Insulating coating method and metal powder core prepared with same |
| CN115003633A (en) * | 2020-01-27 | 2022-09-02 | 保德科技股份有限公司 | Ferrite powder and method for producing same |
-
1992
- 1992-04-27 JP JP4107485A patent/JPH05304020A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101745637A (en) * | 2010-02-11 | 2010-06-23 | 柴秀兰 | Insulating coating method and metal powder core prepared with same |
| CN115003633A (en) * | 2020-01-27 | 2022-09-02 | 保德科技股份有限公司 | Ferrite powder and method for producing same |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19990706 |