JP3021567B2 - Manufacturing method of magnetic fluid - Google Patents
Manufacturing method of magnetic fluidInfo
- Publication number
- JP3021567B2 JP3021567B2 JP2197028A JP19702890A JP3021567B2 JP 3021567 B2 JP3021567 B2 JP 3021567B2 JP 2197028 A JP2197028 A JP 2197028A JP 19702890 A JP19702890 A JP 19702890A JP 3021567 B2 JP3021567 B2 JP 3021567B2
- Authority
- JP
- Japan
- Prior art keywords
- oil
- fine particles
- magnetic fluid
- magnetic
- soluble surfactant
- 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.)
- Expired - Lifetime
Links
- 239000011553 magnetic fluid Substances 0.000 title claims description 20
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 239000010419 fine particle Substances 0.000 claims description 31
- 239000004094 surface-active agent Substances 0.000 claims description 21
- 239000002199 base oil Substances 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 15
- 239000003960 organic solvent Substances 0.000 claims description 13
- 239000006185 dispersion Substances 0.000 claims description 12
- 238000003756 stirring Methods 0.000 claims description 11
- 239000000839 emulsion Substances 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 238000000975 co-precipitation Methods 0.000 claims description 8
- 239000006249 magnetic particle Substances 0.000 claims 1
- 239000003921 oil Substances 0.000 description 11
- 239000000243 solution Substances 0.000 description 10
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 7
- 238000001179 sorption measurement Methods 0.000 description 7
- 239000008096 xylene Substances 0.000 description 7
- -1 Linoleic acid, aliphatic carboxylic acids Chemical class 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 230000005415 magnetization Effects 0.000 description 6
- 239000006228 supernatant Substances 0.000 description 6
- 229910000859 α-Fe Inorganic materials 0.000 description 5
- 238000004220 aggregation Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000002270 dispersing agent Substances 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 150000004996 alkyl benzenes Chemical class 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 125000002843 carboxylic acid group Chemical group 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- IPCSVZSSVZVIGE-UHFFFAOYSA-N hexadecanoic acid Chemical compound CCCCCCCCCCCCCCCC(O)=O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 235000021317 phosphate Nutrition 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 125000000542 sulfonic acid group Chemical group 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- WBIQQQGBSDOWNP-UHFFFAOYSA-N 2-dodecylbenzenesulfonic acid Chemical compound CCCCCCCCCCCCC1=CC=CC=C1S(O)(=O)=O WBIQQQGBSDOWNP-UHFFFAOYSA-N 0.000 description 1
- IICNGCFAUYJWHM-UHFFFAOYSA-N 2-dodecylbenzenesulfonic acid toluene Chemical compound C1(=CC=CC=C1)C.C(CCCCCCCCCCC)C1=C(C=CC=C1)S(=O)(=O)O IICNGCFAUYJWHM-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- 235000021314 Palmitic acid Nutrition 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical group OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 1
- BCKXLBQYZLBQEK-KVVVOXFISA-M Sodium oleate Chemical compound [Na+].CCCCCCCC\C=C/CCCCCCCC([O-])=O BCKXLBQYZLBQEK-KVVVOXFISA-M 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- DTOSIQBPPRVQHS-PDBXOOCHSA-N alpha-linolenic acid Chemical compound CC\C=C/C\C=C/C\C=C/CCCCCCCC(O)=O DTOSIQBPPRVQHS-PDBXOOCHSA-N 0.000 description 1
- 235000020661 alpha-linolenic acid Nutrition 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229940060296 dodecylbenzenesulfonic acid Drugs 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- 229960004488 linolenic acid Drugs 0.000 description 1
- KQQKGWQCNNTQJW-UHFFFAOYSA-N linolenic acid Natural products CC=CCCC=CCC=CCCCCCCCC(O)=O KQQKGWQCNNTQJW-UHFFFAOYSA-N 0.000 description 1
- 229940057995 liquid paraffin Drugs 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- WQEPLUUGTLDZJY-UHFFFAOYSA-N n-Pentadecanoic acid Natural products CCCCCCCCCCCCCCC(O)=O WQEPLUUGTLDZJY-UHFFFAOYSA-N 0.000 description 1
- UFWIBTONFRDIAS-UHFFFAOYSA-N naphthalene-acid Natural products C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 235000021313 oleic acid Nutrition 0.000 description 1
- 125000001117 oleyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])/C([H])=C([H])\C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 229920001281 polyalkylene Polymers 0.000 description 1
- 229920001083 polybutene Polymers 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- XYKIUTSFQGXHOW-UHFFFAOYSA-N propan-2-one;toluene Chemical compound CC(C)=O.CC1=CC=CC=C1 XYKIUTSFQGXHOW-UHFFFAOYSA-N 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
Landscapes
- Compounds Of Iron (AREA)
- Colloid Chemistry (AREA)
- Lubricants (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、磁性流体の製造方法に関する。更に詳しく
は、製造工程を簡略化し、しかも高濃度で分散安定性の
よい磁性流体を製造する方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for producing a magnetic fluid. More specifically, the present invention relates to a method for producing a magnetic fluid which simplifies a production process and has a high concentration and a good dispersion stability.
磁性流体は、磁性微粒子を界面活性剤を用いて水や油
などの溶媒中に安定に分散せしめたものである。The magnetic fluid is obtained by stably dispersing magnetic fine particles in a solvent such as water or oil using a surfactant.
磁性微粒子の調製法としては、コスト、量産性、品質
などの面から、一般に水溶液からの共沈法が望ましい方
法とされている。しかしながら、共沈法で調製した磁性
微粒子は、微粒子表面が親水性であり、このままの状態
では油中へ安定に分散しないので、界面活性剤を磁性微
粒子表面に吸着させ、微粒子表面を疎水性にしてやる必
要がある。As a method for preparing magnetic fine particles, a coprecipitation method from an aqueous solution is generally considered to be a desirable method from the viewpoints of cost, mass productivity, quality, and the like. However, the magnetic fine particles prepared by the coprecipitation method have a hydrophilic fine particle surface, and do not stably disperse in oil in this state, so that a surfactant is adsorbed on the magnetic fine particle surface to make the fine particle surface hydrophobic. I need to do it.
このような疎水化処理の際、オレイン酸ナトリウムの
ような水溶性界面活性剤は、水溶液中で吸着反応を行わ
せることが可能であるが、水溶性界面活性剤で処理した
磁性微粒子は、炭化水素によって代表されるような無極
性乃至低極性の有機溶媒には分散しないかあるいは分散
しても分散濃度が高くならない。In such a hydrophobizing treatment, a water-soluble surfactant such as sodium oleate can cause an adsorption reaction in an aqueous solution, but the magnetic fine particles treated with the water-soluble surfactant are carbonized. It does not disperse in a nonpolar or low-polarity organic solvent typified by hydrogen, or the dispersion concentration does not increase even if it is dispersed.
そこで、本発明者らは先に、水溶性界面活性剤被覆磁
性微粒子に更に油溶性界面活性剤を吸着させることによ
り、分散安定性の向上および高濃度化を実現させている
（特開平１−228,536号公報）。このような方法は、所
期の目的は十分に達成させるものの、工程上および収率
の点で問題がみられ、特に工程が長い割に収率が高くな
いという点で実用上に問題がみられた。Therefore, the present inventors have previously realized an improvement in dispersion stability and an increase in concentration by adsorbing an oil-soluble surfactant on water-soluble surfactant-coated magnetic fine particles. 228,536). Although such a method achieves the intended purpose sufficiently, it has problems in terms of the process and the yield, and in particular, there is no practical problem in that the yield is not high despite the long process. Was done.
このような点を改善させるために、油溶性界面活性剤
を直接磁性微粒子に吸着させる方法が考えられる。従来
法に従えば、磁性微粒子は親水性であるためそれを乾燥
後、ボールミルなどによる粉砕工程と油溶性界面活性剤
の吸着工程とを同時に行わせる方法が採用されるが、こ
の方法では粉砕工程に長い時間がかかり、また乾燥工程
での粒子の凝集のため収率が悪くなるという欠点がみら
れ、上記問題点の解決とはならない。In order to improve such a point, a method of directly adsorbing the oil-soluble surfactant to the magnetic fine particles can be considered. According to the conventional method, since the magnetic fine particles are hydrophilic, a method of drying the magnetic fine particles and then simultaneously performing a pulverizing step using a ball mill or the like and an adsorption step of the oil-soluble surfactant is adopted. However, it takes a long time, and the yield is deteriorated due to the aggregation of particles in the drying step, so that the above problem cannot be solved.
本発明の目的は、共沈法で調製された磁性微粒子から
磁性流体を製造するに際し、製造工程を簡略化し、しか
も高濃度で分散安定性のよい磁性流体を製造する方法を
提供することにある。An object of the present invention is to provide a method for producing a magnetic fluid which simplifies the production process when producing a magnetic fluid from magnetic fine particles prepared by a coprecipitation method and has a high concentration and good dispersion stability. .
かかる本発明の目的は、共沈法で調製された磁性微粒
子の水生ゾルと油溶性界面活性剤を溶解させた水不溶性
有機溶媒溶液とからエマルジョンを強攪拌条件下で形成
させ、磁性微粒子に界面活性剤を吸着させた後、基油へ
の分散前または分散時に水および有機溶媒を除去し、油
溶性界面活性剤吸着磁石微粒子を基油中に分散させ、磁
性流体を製造することによって達成される。The object of the present invention is to form an emulsion from an aqueous sol of magnetic fine particles prepared by a coprecipitation method and a water-insoluble organic solvent solution in which an oil-soluble surfactant is dissolved, under strong stirring conditions, This is achieved by removing the water and the organic solvent before or during dispersion in the base oil after adsorbing the surfactant, dispersing the oil-soluble surfactant-adsorbed magnet fine particles in the base oil, and producing a magnetic fluid. You.
共沈法で調製された磁性微粒子としては、マグネタイ
ト、γ−フェライト、Co−フェライト、Mn−Zn−フェラ
イトなどのフェライト類が水性ゾルの形で用いられる。
水性ゾル中の磁性微粒子の濃度は、次工程におけるエマ
ルジョン形成の容易性、吸着反応の効率的な進行などを
考慮すると、約0.1〜50重量％、好ましくは約１〜30重
量％であることが望ましいが、この範囲外でも吸着反応
が全く不可能となる訳ではない。As the magnetic fine particles prepared by the coprecipitation method, ferrites such as magnetite, γ-ferrite, Co-ferrite, and Mn-Zn-ferrite are used in the form of an aqueous sol.
The concentration of the magnetic fine particles in the aqueous sol may be about 0.1 to 50% by weight, preferably about 1 to 30% by weight in consideration of the ease of emulsion formation in the next step, the efficient progress of the adsorption reaction, and the like. Desirably, outside this range, the adsorption reaction is not at all impossible.
このような磁性微粒子の水性ゾルは、油溶性界面活性
剤を溶解させた水不溶性有機溶媒溶液と強攪拌条件下で
混合され、エマルジョンを形成させる。The aqueous sol of such magnetic fine particles is mixed with a water-insoluble organic solvent solution in which an oil-soluble surfactant is dissolved under a strong stirring condition to form an emulsion.
油溶性界面活性剤としては、カルボン酸基、スルホン
酸基、リン酸基あるいはこれらの塩基を有するもの、好
ましくは磁性微粒子との吸着性からみてカルボン酸基ま
たはスルホン酸基を有するものが用いられる。具体的に
は、例えばオレイン酸、ステアリン酸、パルミチン酸、
リノール酸、リノレン酸などの脂肪族カルボン酸、ある
いはC12〜C24の脂肪族スルホン酸または硫酸エステル、
C6〜C20またはそれ以上の炭素数のアルキル基を有する
アルキルベンゼンスルホン酸などが挙げられる。これら
の界面活性剤の選択は、用いられる磁性流体用基油との
なじみ性などによって行われ、一般的には低極性の基油
程長鎖界面活性剤が用いられ、磁性流体が製造される。As the oil-soluble surfactant, those having a carboxylic acid group, a sulfonic acid group, a phosphoric acid group or a base thereof, preferably those having a carboxylic acid group or a sulfonic acid group in view of their adsorptivity to magnetic fine particles are used. . Specifically, for example, oleic acid, stearic acid, palmitic acid,
Linoleic acid, aliphatic carboxylic acids such as linolenic acid, or C 12 to C 24 aliphatic sulfonic acids or sulfates,
Such as alkylbenzene sulfonic acid having a C 6 -C 20 or more alkyl groups of carbon number like. The selection of these surfactants is made depending on the compatibility with the magnetic fluid base oil to be used and the like. Generally, a longer-chain surfactant is used for a lower polarity base oil, and a magnetic fluid is produced.
油溶性界面活性剤は、それを溶解させる水不溶性有機
溶媒の溶液として用いられる。水不溶性有機溶媒として
は、無極性乃至低極性の基油との相溶性の点から、炭化
水素系の有機溶媒が好ましく、界面活性剤は一般に約0.
01〜５モル濃度程度の溶液として用いられる。The oil-soluble surfactant is used as a solution in a water-insoluble organic solvent in which it is dissolved. As the water-insoluble organic solvent, a hydrocarbon-based organic solvent is preferred from the viewpoint of compatibility with a nonpolar to low-polarity base oil, and a surfactant is generally used in an amount of about 0.
It is used as a solution of about 01 to 5 molar concentration.
エマルジョンの形成は、磁性微粒子の水性ゾルと油溶
性界面活性剤を溶解させた水不溶性有機溶媒溶液とを、
室温乃至約100℃の温度で約0.5〜３時間程度ホモジナイ
ザなどを用いて攪拌することによって行われ、粒径の細
かいエマルジョンを形成させるために、強攪拌条件下で
攪拌することが行われる。The formation of the emulsion is performed by combining an aqueous sol of magnetic fine particles and a water-insoluble organic solvent solution in which an oil-soluble surfactant is dissolved,
The stirring is performed by using a homogenizer or the like at a temperature of room temperature to about 100 ° C. for about 0.5 to 3 hours. In order to form an emulsion having a small particle diameter, stirring is performed under strong stirring conditions.
このようなエマルジョンの形成により、油溶性界面活
性剤は磁性微粒子の表面に吸着される。その後、基油中
への分散が行われるが、その際水および有機溶媒の除去
が行われる。水および有機溶媒の除去は、基油中への分
散前あるいは分散時に行われる。分散前に除去する場合
には、エバポレータなどを用いて行われ、残渣をトルエ
ン−アセトン等量混合液で１回乃至数回洗浄後乾燥し、
所望の基油および必要に応じて分散剤を添加し、ホモジ
ナイザや超音波で処理することにより、磁性流体が得ら
れる。また、分散時に行われる場合には、吸着反応させ
て形成された油層、水層の２層の内、油層のみを取り出
し、これに基油および必要に応じて分散剤を添加した
後、エバポレータなどを用いて水および有機溶媒を除去
することにより、磁性流体が得られる。By forming such an emulsion, the oil-soluble surfactant is adsorbed on the surface of the magnetic fine particles. Thereafter, dispersion in the base oil is carried out, while removing water and the organic solvent. The removal of water and the organic solvent is performed before or during dispersion in the base oil. In the case of removing before dispersion, the removal is performed using an evaporator or the like, and the residue is washed once or several times with a mixed solution of an equal amount of toluene-acetone and dried,
A magnetic fluid can be obtained by adding a desired base oil and, if necessary, a dispersant and treating with a homogenizer or ultrasonic waves. In addition, when the dispersion is performed, only the oil layer is taken out of the two oil layers formed by the adsorption reaction and the aqueous layer, and the base oil and the dispersant are added thereto, and then the evaporator is used. The magnetic fluid is obtained by removing water and the organic solvent using.
基油としては、前記特許公開公報にも記載される如
く、25℃において0.1mmHg以下、好ましくは0.01mmHg以
下の蒸気圧を有する液体、例えば天然油であるホワイト
オイル（流動パラフィン）、鉱油、スピンドル油など、
あるいは合成油である高級アルキルベンゼン、高級アル
キルナフタレン、ポリブテン（分子量約300〜2000）、
ジカルボン酸ジエステルなどが、最終的に得られる磁性
流体中の磁性微粒子の分散濃度が約10〜50重量％となる
ような割合で用いられる。Examples of the base oil include liquids having a vapor pressure of 0.1 mmHg or less at 25 ° C., preferably 0.01 mmHg or less, such as white oil (liquid paraffin), mineral oil, spindle oil, and the like, as described in the above-mentioned Patent Publication. Such as oil,
Alternatively, synthetic oils such as higher alkyl benzene, higher alkyl naphthalene, polybutene (molecular weight of about 300 to 2,000),
A dicarboxylic acid diester or the like is used in such a ratio that the dispersion concentration of the magnetic fine particles in the finally obtained magnetic fluid is about 10 to 50% by weight.
また、必要に応じて基油と共に用いられる分散剤とし
ては、やはり前期特許公開公報にも記載されているＮ−
ポリアルキレンポリアミン置換アルケニルコハク酸イミ
ド、モノ−またはジ−オキシアルキレン基含有リン酸エ
ステル、非イオン界面活性剤などが用いられる。The dispersant used together with the base oil, if necessary, includes N-
Polyalkylene polyamine-substituted alkenyl succinimides, mono- or di-oxyalkylene group-containing phosphates, nonionic surfactants and the like are used.
本発明方法によれば、共沈法で調製された親水性の磁
性微粒子を、凝集、乾燥、粉砕などの工程を経ることな
く、油溶性の界面活性剤を直接磁性微粒子に吸着させる
ことが可能となり、また磁性微粒子の凝集を招くおそれ
もないので、その結果無極性乃至低極性の基油中に高濃
度で分散安定性のよい磁性流体が、短時間で効率よく製
造することが可能となる。According to the method of the present invention, it is possible to adsorb an oil-soluble surfactant directly to magnetic fine particles without going through steps such as aggregation, drying and pulverization of hydrophilic magnetic fine particles prepared by a coprecipitation method. In addition, since there is no possibility of causing aggregation of the magnetic fine particles, a magnetic fluid having high concentration and good dispersion stability in a non-polar or low-polar base oil can be efficiently produced in a short time. .
これは、強攪拌下におけるエマルジョンを利用するこ
とにより、油水界面に油溶性界面活性剤をきれいに配向
させ、しかもその界面の面積を増大させることによっ
て、磁性微粒子に効率よく吸着させたことによる効果と
考えられる。This is because the emulsion under strong stirring is used to orient the oil-soluble surfactant at the oil-water interface neatly, and the effect of efficiently adsorbing the magnetic fine particles by increasing the area of the interface is increased. Conceivable.
次に、実施例について本発明を説明する。 Next, the present invention will be described with reference to examples.
実施例１ FeCl2・4H2O 100gおよびFeCl3・6H2O 270gをそれぞれ
100mlのイオン交換水に完全に溶解した後両者を混合
し、攪拌下に12％アンモニア水750mlをそこに２時間か
けて滴下し、Fe3O4微粒子を形成させた。Example 1 100 g of FeCl 2 .4H 2 O and 270 g of FeCl 3 .6H 2 O
After completely dissolving in 100 ml of ion-exchanged water, the two were mixed, and 750 ml of 12% aqueous ammonia was added dropwise thereto over 2 hours with stirring to form Fe 3 O 4 fine particles.
80℃で30分間攪拌下で熟成した後磁石下に静置し、沈
降したFe3O4微粒子の上澄液を除去後、再び等量のイオ
ン交換水を加えてFe3O4の洗浄を行い、このような操作
を４回くり返した。最後に上澄液を除去し、Fe3O4の水
性ゾルを得た。このときのFe3O4微粒子の濃度は、30重
量％とされた。After aging under stirring at 80 ° C. for 30 minutes, the mixture was allowed to stand under a magnet, the supernatant of the precipitated Fe 3 O 4 fine particles was removed, and an equal amount of ion-exchanged water was added again to wash the Fe 3 O 4 . This operation was repeated four times. Finally, the supernatant was removed to obtain an aqueous sol of Fe 3 O 4 . At this time, the concentration of the Fe 3 O 4 fine particles was 30% by weight.
次に、この水性ゾルに0.5モル濃度のエルカ酸キシレ
ン溶液1200mlを加え、強攪拌下でエマルジョンを形成さ
せた。温度を上昇させ、80〜90℃で40分間吸着反応させ
た後、静置、放冷した。油層と水層とに分かれた２層の
内の油層だけを分離し、基油としてのアルキルナフタレ
ン200gを加え、ロ−タリエバポレータでキシレンを除去
した後、遠心分離（15000G、30分間）して、上澄液を回
収すると、そこに飽和磁化210Gの磁性流体が得られた。Next, 1200 ml of a 0.5 molar xylene erucate solution was added to the aqueous sol, and an emulsion was formed under strong stirring. After raising the temperature and causing an adsorption reaction at 80 to 90 ° C. for 40 minutes, the mixture was allowed to stand and cooled. Separate only the oil layer of the two layers separated into an oil layer and an aqueous layer, add 200 g of alkylnaphthalene as a base oil, remove xylene with a rotary evaporator, and centrifuge (15000 G, 30 minutes) When the supernatant was recovered, a magnetic fluid having a saturation magnetization of 210 G was obtained.
実施例２ 実施例１と同様にして調製したFe3O4の水性ゾル（濃
度20重量％）300mlに、0.5モル濃度のドデシルベンゼン
スルホン酸トルエン溶液1000mlを加え、強攪拌下でエマ
ルジョンを形成させた。昇温後80℃で60分間吸着反応さ
せた後、イオン交換水およびトルエンのすべてをロータ
リエバポレータを用いて除去した。Example 2 To 300 ml of an aqueous sol of Fe 3 O 4 (concentration: 20% by weight) prepared in the same manner as in Example 1, 1000 ml of a 0.5 molar dodecylbenzenesulfonic acid toluene solution was added, and an emulsion was formed under strong stirring. Was. After the temperature was raised and the adsorption reaction was performed at 80 ° C. for 60 minutes, all of the ion-exchanged water and toluene were removed using a rotary evaporator.
残渣をトルエン−アセトン等量混合液で洗浄後、ポリ
オキシエチレンノニルフェニルリン酸エステル5gおよび
拡散ポンプオイル（松村石油製品SX）45gを加え、ホモ
ジナイザ処理（10000rpm、30分間）後、超音波処理を２
日間行った。その後、遠心分離（15000G、30分間）して
上澄液を回収すると、飽和磁化450Gの磁性流体が得られ
た。The residue was washed with a mixture of equal volumes of toluene and acetone, 5 g of polyoxyethylene nonylphenyl phosphate and 45 g of diffusion pump oil (Matsumura Petroleum Products SX) were added, homogenized (10000 rpm, 30 minutes), and then sonicated. 2
Went for days. Thereafter, the supernatant was collected by centrifugation (15000 G, 30 minutes), and a magnetic fluid having a saturation magnetization of 450 G was obtained.
実施例３ 実施例２において、ドデシルベンゼンスルホン酸の代
わりに、同量のオレイルアシッドホスフェートを用いる
と、飽和磁化350Gの磁性流体が得られた。Example 3 In Example 2, when the same amount of oleyl acid phosphate was used instead of dodecylbenzene sulfonic acid, a magnetic fluid having a saturation magnetization of 350 G was obtained.
実施例４ 実施例２において、Fe3O4水性ゾルの代わりに、CoCl2
とFeCl3とから共沈法で調製されたCo−フェライト微粒
子の水性ゾルを用い、また基油としてアルキルナフタレ
ンを用いると、飽和磁化300Gの磁性流体が得られた。Example 4 In Example 2, CoCl 2 was used instead of the aqueous Fe 3 O 4 sol.
A magnetic fluid having a saturation magnetization of 300 G was obtained by using an aqueous sol of Co-ferrite fine particles prepared by coprecipitation with FeCl 3 and alkylnaphthalene as a base oil.
比較例１ 実施例１と同様にして調製されたFe3O4水性ゾルを一
旦乾燥させた後、0.5モル濃度のエルカ酸キシレン溶液1
200mlおよびアルキルナフタレン200gを加え、１週間ボ
ールミルによる粉砕・分散処理を行った。Comparative Example 1 After the aqueous Fe 3 O 4 sol prepared in the same manner as in Example 1 was once dried, a 0.5 molar xylene erucate solution 1 was prepared.
200 ml and 200 g of alkylnaphthalene were added, and pulverized and dispersed by a ball mill for 1 week.
ボールミルから取り出した液から、ロータリエバポレ
ータでキシレンを除去した後、遠心分離（15000G、30分
間）して上澄液を回収すると、飽和磁化が40Gの磁性流
体しか得られなかった。The xylene was removed from the liquid taken out of the ball mill with a rotary evaporator, and then centrifuged (15,000 G, 30 minutes) to recover the supernatant. As a result, only a magnetic fluid having a saturation magnetization of 40 G was obtained.
比較例２ 比較例１と同様に調製されたFe3O4水性ゾルの乾燥物
に、0.5モル濃度のエルカ酸キシレン溶液200mlを加え、
ホモジナイザ処理（10000rpm、60分間）した後、再び同
濃度のエルカ酸キシレン溶液1000mlおよびアルキルナフ
タレン200gを加え、ボールミル処理を１週間行った。Comparative Example 2 To a dried product of the aqueous Fe 3 O 4 sol prepared in the same manner as in Comparative Example 1, 200 ml of a 0.5 molar xylene erucate solution was added.
After homogenizer treatment (10000 rpm, 60 minutes), 1000 ml of the same concentration of xylene erucate solution and 200 g of alkylnaphthalene were added again, and ball mill treatment was performed for one week.
ボールミルから取り出した液から、ロータリエバポレ
ータでキシレンを除去した後、遠心分離（15000G、30分
間）して上澄液を回収すると、飽和磁化が65Gの磁性流
体しか得られなかった。The xylene was removed from the liquid taken out from the ball mill using a rotary evaporator, and then centrifuged (15000 G, 30 minutes) to recover the supernatant, yielding only a magnetic fluid with a saturation magnetization of 65 G.
Claims (1)
と油溶性界面活性剤を溶解させた水不溶性有機溶媒溶液
とからエマルジョンを強攪拌条件下で形成させ、磁性微
粒子に界面活性剤を吸着させた後、基油への分散前また
は分散時に水および有機溶媒を除去し、油溶性界面活性
剤吸着磁石微粒子を基油中に分散させることを特徴とす
る磁性流体の製造方法。An emulsion is formed from an aqueous sol of magnetic fine particles prepared by a coprecipitation method and a water-insoluble organic solvent solution in which an oil-soluble surfactant is dissolved, under strong stirring conditions. A method for producing a magnetic fluid, comprising removing water and an organic solvent before or at the time of dispersion in a base oil after adsorbing magnetic particles, and dispersing oil-soluble surfactant-adsorbed magnet fine particles in the base oil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2197028A JP3021567B2 (en) | 1990-07-25 | 1990-07-25 | Manufacturing method of magnetic fluid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2197028A JP3021567B2 (en) | 1990-07-25 | 1990-07-25 | Manufacturing method of magnetic fluid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0481498A JPH0481498A (en) | 1992-03-16 |
| JP3021567B2 true JP3021567B2 (en) | 2000-03-15 |
Family
ID=16367547
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2197028A Expired - Lifetime JP3021567B2 (en) | 1990-07-25 | 1990-07-25 | Manufacturing method of magnetic fluid |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3021567B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4581619B2 (en) * | 2004-10-15 | 2010-11-17 | 戸田工業株式会社 | Magnetic fluid and manufacturing method thereof |
-
1990
- 1990-07-25 JP JP2197028A patent/JP3021567B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0481498A (en) | 1992-03-16 |
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