JPS638488A - Production of magnetic fluid - Google Patents

Production of magnetic fluid

Info

Publication number
JPS638488A
JPS638488A JP61152151A JP15215186A JPS638488A JP S638488 A JPS638488 A JP S638488A JP 61152151 A JP61152151 A JP 61152151A JP 15215186 A JP15215186 A JP 15215186A JP S638488 A JPS638488 A JP S638488A
Authority
JP
Japan
Prior art keywords
base oil
low
boiling
boiling point
magnetic fluid
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.)
Granted
Application number
JP61152151A
Other languages
Japanese (ja)
Other versions
JPH0765063B2 (en
Inventor
Yasuki Karita
刈田 保樹
Takao Sugano
隆夫 菅野
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nok Corp
Original Assignee
Nok Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nok Corp filed Critical Nok Corp
Priority to JP61152151A priority Critical patent/JPH0765063B2/en
Publication of JPS638488A publication Critical patent/JPS638488A/en
Publication of JPH0765063B2 publication Critical patent/JPH0765063B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/44Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Lubricants (AREA)
  • Soft Magnetic Materials (AREA)

Abstract

PURPOSE:To obtain a magnetic fluid dispersed in a high-boiling base oil reading, by dripping a dispersion of ultrafine particles of ferrite having adsorbed a surface active agent in a low-boiling base oil into a hot high-boiling base oil and evaporating the low-boiling base oil to carry out replacement of the base oil. CONSTITUTION:(A) A dispersion of ultrafine particles of ferrite having adsorbed a surface active agent in a low-boiling base oil is dipped into (B) high-boiling base oil having compatibility with the low-boiling base oil and heated at >=150 deg.C, and low-boiling base oil is evaporated and replacement of the base oil is carried out to give the aimed magnetic fluid. A hydrocarbon solvent having 30-110 deg.C boiling point is preferable as the low-boiling base oil and a higher alkyl- substituted naphthalene of dicarboxylic acid di-higher-alkyl ester, etc., is preferable as the high-boiling base oil.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、磁性流体の製造法に関する。更に詳しくは、
界面活性剤を吸着させたフェライト類超微粒子を所望の
高沸点基油中に分散させる磁性流体の製造法に関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing magnetic fluids. For more details,
The present invention relates to a method for producing a magnetic fluid in which ultrafine ferrite particles adsorbed with a surfactant are dispersed in a desired high-boiling base oil.

〔従来の技術〕[Conventional technology]

強アルカリによる共沈法で得られたフェライト類(マグ
ネタイト、 Mn−フェライ1−1Ni−フェライト、
Mn−Ni−フェライト、Ni−Zn−フェライトなど
)の超微粒子の水性けん濁に、オレイン酸ナトリウム、
ソジウムジオクチルスルホンサクシネート(商品名磁性
Aerosol OT)などによって代表される各種の
界面活性剤を加え、これを例えば90℃、30分間加熱
することにより、フェライト類超微粒子に界面活性剤を
吸着させ、この界面活性剤吸着フェライト類超微粒子を
減圧vi:M!シた後、エイコシルナフタリンによって
代表される高級アルキル置換ナフタリン、セバシン酸ジ
オクチル、アジピン酸ジオクチルによって代表されるジ
カルボン酸ジ高級アルキルエステルなどの沸点約150
℃以上の高沸点基油中に、超音波を照射しながら分散せ
しめることが従来から行われている。これは、磁性流体
が濃縮されると超微粒子の分散安定生が悪化するために
、低蒸気圧、高沸点の基油を用いて、基油の蒸発による
濃縮を防止せんとしているのである。しかしながら、こ
のような分散方法よったのでは、凝集粉にこれらの基油
が浸透しないため、全く分散が行われないことが多い。
Ferrites (magnetite, Mn-ferrite 1-1Ni-ferrite,
Sodium oleate,
By adding various surfactants such as sodium dioctyl sulfone succinate (trade name: Magnetic Aerosol OT) and heating this at 90°C for 30 minutes, the surfactant is adsorbed onto the ferrite ultrafine particles. , this surfactant-adsorbed ferrite ultrafine particles are depressurized vi:M! After oxidation, higher alkyl-substituted naphthalenes such as eicosylnaphthalene, dicarboxylic acid di-higher alkyl esters such as dioctyl sebacate and dioctyl adipate have a boiling point of about 150.
Conventionally, dispersion has been carried out in a high boiling point base oil at a temperature of 0.degree. C. or higher while irradiating ultrasonic waves. This is because when the magnetic fluid is concentrated, the dispersion stability of the ultrafine particles deteriorates, so a base oil with a low vapor pressure and a high boiling point is used to prevent concentration due to evaporation of the base oil. However, if such a dispersion method is used, these base oils do not penetrate into the agglomerated powder, so dispersion is often not performed at all.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

そこで、本発明者らは、界面活性剤吸着フェライト類超
微粒子を所望の高沸点基油中に分散させる方法について
検討した結果、低沸点基油に一旦分散させたフェライト
類超微粒子を溶剤基油の置換法により高沸点基油に分散
させる方法がきわめて有効であることを見出した。
Therefore, the present inventors investigated a method of dispersing surfactant-adsorbed ultrafine ferrite particles into a desired high-boiling point base oil, and found that the ultrafine ferrite particles, which were once dispersed in a low-boiling point base oil, were dispersed in a solvent base oil. We have found that the method of dispersing in high-boiling base oil using the substitution method described above is extremely effective.

〔問題点を解決するための手段〕[Means for solving problems]

従って、本発明は磁性流体の製造法に係り、磁性流体の
製造法は、界面活性剤を吸着させたフェライト超微粒子
の低沸点基油分散物を、該低沸点基油と相溶性を有しか
つ約150℃以上に加熱された高沸点基油中へ滴下する
ことにより低沸点基油を蒸発させる溶剤基油の置換法に
よって行われる。
Therefore, the present invention relates to a method for producing a magnetic fluid, which includes dispersing a low-boiling point base oil dispersion of ultrafine ferrite particles adsorbed with a surfactant into a low-boiling point base oil having compatibility with the low-boiling point base oil. It is also carried out by a solvent base oil displacement method in which low boiling point base oil is evaporated by dropping it into high boiling point base oil heated to about 150° C. or higher.

界面活性剤を吸着させたフェライト類超微粒子としては
、従来公知のものが乾燥した上でそのまま用いられ、こ
れを低沸点基油、好ましくはシクロヘキサン、トルエン
などの沸点が約3(1−150℃。
As ultrafine ferrite particles adsorbed with a surfactant, conventionally known ones can be used as they are after drying, and these can be used as they are with a low boiling point base oil, preferably a base oil with a boiling point of about 3 (1-150°C) such as cyclohexane or toluene. .

好ましくは約30〜110℃の炭化水素溶剤中に一旦分
散させる。ここでは、一般に超微粒子濃度が約0゜1〜
1.3g/m12になるように低沸点基油が用いられる
。これ以上の濃度に調製されると、フェライト類超微粒
子はゲル化してしまい、磁性液体をもはや形成しない。
Preferably, it is once dispersed in a hydrocarbon solvent at about 30 to 110°C. Here, the ultrafine particle concentration is generally about 0°1~
A low boiling point base oil is used to give 1.3 g/m12. If the concentration is higher than this, the ultrafine ferrite particles will gel and will no longer form a magnetic liquid.

次いで、この低沸点基油分散物(磁性流体)を。Next, this low boiling point base oil dispersion (magnetic fluid).

最終的に求められる磁性流体の超微粒子濃度に応じた量
の、低沸点基油と相溶性を有する高沸点基油であって、
約150℃以上に加熱されたもの、例えば270℃に加
熱されたエイコシルナフタリン、200℃に加熱された
セバシン酸ジオクチル、180℃に加熱されたアジピン
酸ジオクチル中などへ滴下すると、この加熱温度よりか
なり低い沸点を有する低沸点基油は滴下と同時に蒸発除
去され、かかる溶剤基油の置換によって高沸点基油分散
磁性流体が得られる。
A high boiling point base oil that is compatible with the low boiling point base oil in an amount corresponding to the ultimately required ultrafine particle concentration of the magnetic fluid,
When dropped into something heated to about 150°C or higher, such as eicosylnaphthalene heated to 270°C, dioctyl sebacate heated to 200°C, or dioctyl adipate heated to 180°C, the reaction temperature will exceed this heating temperature. Low-boiling base oils with fairly low boiling points are evaporated off simultaneously with the dropwise addition, and replacement of such solvent base oils yields high-boiling base oil-dispersed magnetic fluids.

〔発明の効果〕〔Effect of the invention〕

本発明方法によれば、界面活性剤吸着フェライト類超微
粒子を一旦低沸点基油に分散させ、これを溶剤基油の置
換法により高沸点基油と置換することにより、低沸点基
油分散磁性流体の良好な分散性および飽和磁化を保持し
たまま、フェライト類超微粒子を高沸点基油に分散させ
た磁性流体を得ることができる。
According to the method of the present invention, ultrafine particles of surfactant-adsorbed ferrites are once dispersed in a low-boiling point base oil, and this is replaced with a high-boiling point base oil by a solvent base oil substitution method, thereby creating a low-boiling point base oil-dispersed magnetic material. It is possible to obtain a magnetic fluid in which ultrafine ferrite particles are dispersed in a high-boiling base oil while maintaining good dispersibility and saturation magnetization of the fluid.

〔実施例〕〔Example〕

次に、実施例について本発明を説明する。 Next, the present invention will be explained with reference to examples.

実施例 FaCl、・nH,020gおよびFeC1,・6H,
050gをそれぞれ水Loom Qに溶解させた後混合
し、そこに6N NaOH水溶液をpl−111になる
迄、10m07分の滴下速度で攪拌下に滴下する。滴下
終了後、100°Cで30分間加熱還流させた後冷却し
、水で洗浄する。洗浄された水性けん濁液の全量を50
0m Qとした後、そこにオレイン酸ナチリウム6gを
加え、90℃で30分間加熱してから水で洗浄し、乾燥
する。
Examples FaCl, .nH, 020 g and FeCl, .6H,
After dissolving 050 g of each in water Loom Q, they are mixed, and a 6N NaOH aqueous solution is added dropwise thereto while stirring at a dropping rate of 10 m07 min until the pl-111. After the dropwise addition is completed, the mixture is heated under reflux at 100°C for 30 minutes, cooled, and washed with water. The total volume of washed aqueous suspension was
After setting the temperature to 0 mQ, 6 g of sodium oleate was added thereto, heated at 90° C. for 30 minutes, washed with water, and dried.

得られた界面活性剤吸着マグネタイト超微粒子23gを
シクロヘキサンLoom Qに分散させ、飽和磁化3.
4 X 10−’T(1,3にA/m印加時)の磁性流
体を得た。
23 g of the obtained surfactant-adsorbed magnetite ultrafine particles were dispersed in cyclohexane Loom Q to obtain a saturation magnetization of 3.
A magnetic fluid of 4×10-'T (when A/m was applied to 1 and 3) was obtained.

この磁性流体100u+ Qを、270℃のエイコシル
ナフタリン中に毎分10m Qの滴下速度で滴下すると
、滴下と同時にシクロヘキサンが蒸発し、速やかに溶剤
基油の置換が行われ、飽和磁化3.4 X 1O−3T
(1゜3KA/m印加時)の高沸点基油分散磁性流体が
得られた。
When 100 u+ Q of this magnetic fluid is dropped into eicosylnaphthalene at 270°C at a dropping rate of 10 m/min, cyclohexane evaporates at the same time as the dropping, and the solvent base oil is quickly replaced, resulting in a saturation magnetization of 3.4 X 1O-3T
A high boiling point base oil-dispersed magnetic fluid was obtained (at the time of application of 1°3 KA/m).

比較例 実施例で用いられた界面活性剤吸着マグネタイト超微粒
子23gをエイコシルナフタリン100mQ中に加え、
超音波照射を行なったが、殆んど分散は生じなかった。
Comparative Example 23g of surfactant-adsorbed magnetite ultrafine particles used in the example were added to 100mQ of eicosylnaphthalene,
Ultrasonic irradiation was performed, but almost no dispersion occurred.

Claims (1)

【特許請求の範囲】 1、界面活性剤を吸着させたフェライト類微粒子の低沸
点基油分散物を、該低沸点基油と相溶性を有しかつ約1
50℃以上に加熱された高沸点基油中へ滴下することに
より低沸点基油を蒸発させ、溶剤基油の置換を行なうこ
とを特徴とする磁性流体の製造法。 2、低沸点基油が沸点約30〜110℃の炭化水素溶剤
である特許請求の範囲第1項記載の磁性流体の製造法。 3、高沸点基油が高級アルキル置換ナフタリンである特
許請求の第1項記載の磁性流体の製造法。 4、高沸点基油がジカルボン酸ジ高級アルキルエステル
である特許請求の範囲第1項記載の磁性流体の製造法。
[Claims] 1. A low-boiling point base oil dispersion of ferrite fine particles adsorbed with a surfactant, which has compatibility with the low-boiling point base oil and about 1.
A method for producing a magnetic fluid, which comprises evaporating a low boiling point base oil by dropping it into a high boiling point base oil heated to 50° C. or higher to replace the solvent base oil. 2. The method for producing a magnetic fluid according to claim 1, wherein the low boiling point base oil is a hydrocarbon solvent having a boiling point of about 30 to 110°C. 3. The method for producing a magnetic fluid according to claim 1, wherein the high-boiling base oil is a higher alkyl-substituted naphthalene. 4. The method for producing a magnetic fluid according to claim 1, wherein the high-boiling base oil is a dihigher alkyl dicarboxylic acid ester.
JP61152151A 1986-06-27 1986-06-27 Magnetic fluid manufacturing method Expired - Lifetime JPH0765063B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61152151A JPH0765063B2 (en) 1986-06-27 1986-06-27 Magnetic fluid manufacturing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP61152151A JPH0765063B2 (en) 1986-06-27 1986-06-27 Magnetic fluid manufacturing method

Publications (2)

Publication Number Publication Date
JPS638488A true JPS638488A (en) 1988-01-14
JPH0765063B2 JPH0765063B2 (en) 1995-07-12

Family

ID=15534141

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61152151A Expired - Lifetime JPH0765063B2 (en) 1986-06-27 1986-06-27 Magnetic fluid manufacturing method

Country Status (1)

Country Link
JP (1) JPH0765063B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010266007A (en) * 2009-05-15 2010-11-25 Burest Kogyo Kenkyusho Co Ltd Holder for dew condensation preventing plate

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58174495A (en) * 1982-04-07 1983-10-13 Nippon Seiko Kk Preparation of magnetic fluid

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58174495A (en) * 1982-04-07 1983-10-13 Nippon Seiko Kk Preparation of magnetic fluid

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010266007A (en) * 2009-05-15 2010-11-25 Burest Kogyo Kenkyusho Co Ltd Holder for dew condensation preventing plate

Also Published As

Publication number Publication date
JPH0765063B2 (en) 1995-07-12

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