JPH061728B2 - Magnetic fluid manufacturing method - Google Patents
Magnetic fluid manufacturing methodInfo
- Publication number
- JPH061728B2 JPH061728B2 JP61039597A JP3959786A JPH061728B2 JP H061728 B2 JPH061728 B2 JP H061728B2 JP 61039597 A JP61039597 A JP 61039597A JP 3959786 A JP3959786 A JP 3959786A JP H061728 B2 JPH061728 B2 JP H061728B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- ultrafine particles
- organic solvent
- magnetic fluid
- hydrogel
- 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 24
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 239000011882 ultra-fine particle Substances 0.000 claims description 44
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 34
- 239000000017 hydrogel Substances 0.000 claims description 23
- 239000003960 organic solvent Substances 0.000 claims description 22
- 239000002245 particle Substances 0.000 claims description 19
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims description 14
- 239000007788 liquid Substances 0.000 claims description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 9
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 8
- 150000003839 salts Chemical class 0.000 claims description 6
- 239000004094 surface-active agent Substances 0.000 claims description 6
- 229910001289 Manganese-zinc ferrite Inorganic materials 0.000 claims description 5
- JIYIUPFAJUGHNL-UHFFFAOYSA-N [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[Mn++].[Mn++].[Mn++].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Zn++].[Zn++] Chemical compound [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[Mn++].[Mn++].[Mn++].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Fe+3].[Zn++].[Zn++] JIYIUPFAJUGHNL-UHFFFAOYSA-N 0.000 claims description 5
- 239000010419 fine particle Substances 0.000 claims description 5
- 238000005406 washing Methods 0.000 claims description 4
- 238000009826 distribution Methods 0.000 claims description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 18
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 14
- 239000000499 gel Substances 0.000 description 9
- 239000013078 crystal Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 150000004679 hydroxides Chemical class 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- 150000004706 metal oxides Chemical class 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 238000004220 aggregation Methods 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 3
- 230000005389 magnetism Effects 0.000 description 3
- 229910000000 metal hydroxide Inorganic materials 0.000 description 3
- 229910044991 metal oxide Inorganic materials 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 150000004692 metal hydroxides Chemical class 0.000 description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- 229910021380 Manganese Chloride Inorganic materials 0.000 description 1
- GLFNIEUTAYBVOC-UHFFFAOYSA-L Manganese chloride Chemical compound Cl[Mn]Cl GLFNIEUTAYBVOC-UHFFFAOYSA-L 0.000 description 1
- AMQJEAYHLZJPGS-UHFFFAOYSA-N N-Pentanol Chemical compound CCCCCO AMQJEAYHLZJPGS-UHFFFAOYSA-N 0.000 description 1
- 125000003158 alcohol group Chemical group 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- WPUJEWVVTKLMQI-UHFFFAOYSA-N benzene;ethoxyethane Chemical compound CCOCC.C1=CC=CC=C1 WPUJEWVVTKLMQI-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 235000002867 manganese chloride Nutrition 0.000 description 1
- 239000011565 manganese chloride Substances 0.000 description 1
- 229940099607 manganese chloride Drugs 0.000 description 1
- 229910001510 metal chloride Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- -1 propanol or butanol Chemical compound 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/44—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids
- H01F1/445—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of magnetic liquids, e.g. ferrofluids the magnetic component being a compound, e.g. Fe3O4
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Colloid Chemistry (AREA)
- Soft Magnetic Materials (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は磁性を帯びた超微粒子を利用する磁性流体の製
造方法に係り、詳しくは酸化鉄等の磁性を帯びた超微粒
子を界面活性剤に入れた液体に混ぜた磁性流体の製造方
法に関する。Description: TECHNICAL FIELD The present invention relates to a method for producing a magnetic fluid using magnetic ultrafine particles, and more specifically, to magnetic ultrafine particles such as iron oxide as a surfactant. The present invention relates to a method for producing a magnetic fluid mixed with a liquid put in a container.
磁性流体は磁性を帯びた超微粒子を界面活性剤を入れた
液体に混ぜたものである。ここで、界面活性剤とは液体
に溶けると溶液の表面張力を著しく減少させるような物
質である。これによって磁性を帯びた超微粒子が液体中
に均一に散ることになり液体すべてに磁性があるように
ふるまう。元来、磁性流体は宇宙服やヘルメットなどの
継目部分のシール材として開発されたものであり、ヘル
メットの枠に磁石を付け、もう一方に磁性流体のシール
をはると、液体が磁石に付くと同時に完全密閉すること
ができる。その他、フライホイール，磁気インク，比重
選別などに利用される。A magnetic fluid is a mixture of magnetic ultrafine particles and a liquid containing a surfactant. Here, the surfactant is a substance that, when dissolved in a liquid, significantly reduces the surface tension of the solution. As a result, the ultrafine particles having magnetism are uniformly dispersed in the liquid, and the liquid behaves as if it were magnetic. Originally, magnetic fluid was developed as a sealing material for seams such as space suits and helmets. When a magnet is attached to the frame of the helmet and a magnetic fluid seal is attached to the other, the liquid attaches to the magnet. At the same time, it can be completely sealed. In addition, it is used for flywheels, magnetic ink, and specific gravity sorting.
従来、磁性流体に使用する磁性を帯びた超微粒子として
液相法により製造したものがあった。Conventionally, there have been manufactured by a liquid phase method as magnetic ultrafine particles used for a magnetic fluid.
通常、水溶性金属塩化溶液とアルカリ（NH4OH,NaOH,KO
H）水溶液との中和反応又は共沈反応によって生成する
非水溶性又は難水溶性の金属、非金属酸化物又は水酸化
物のヒドロゲルは第５図に示すようにほとんど無定形な
微粒子又は超微粒子である。Usually, water-soluble metal chloride solution and alkali (NH 4 OH, NaOH, KO
H) Hydrogels of water-insoluble or sparingly water-soluble metals, non-metal oxides or hydroxides formed by neutralization reaction or coprecipitation reaction with aqueous solution are almost amorphous fine particles or ultrafine particles as shown in FIG. It is a fine particle.
この反応は次の如くである。This reaction is as follows.
酸化鉄ヒドロゲル Fe2(SO4)3aq.solu+excess NH4OH→Fe(OH)Xゲ ル+NH4Cl+excess NH4OH この反応で生成したヒドロゲルは超微細な粒子からな
り、共存する塩類を純水にて洗浄除去すれば高純度の金
属酸化物又は金属水酸化物のヒドロゲルの水ペーストが
得られ、これをこのまま乾燥して得られた磁性を帯びた
超微粒子を磁性流体に利用するものがあった。Iron oxide hydrogel Fe 2 (SO 4 ) 3 aq.solu + excess NH 4 OH → Fe (OH) X gel + NH 4 Cl + excess NH 4 OH The hydrogel produced by this reaction consists of ultrafine particles and coexists. If the salt is washed and removed with pure water, a high-purity metal oxide or metal hydroxide hydrogel water paste is obtained, and the ultrafine particles with magnetism obtained by drying this as it is are converted into a magnetic fluid. There was something to use.
ところで、従来の液相法で製造した超微粒子を乾燥する
ことにより乾燥超微粒子を得ると、水の蒸発に伴う強い
表面張力が働くため、単分散した乾燥超微粒子は得られ
ないで、指頭に強く感じる２次凝集塊となる。又、水を
アルコールやその他表面張力の小さい非水溶媒でおきか
えて乾燥しても、水の場合よりやや凝集力の小さい塊状
粒子が得られるにすぎない。そのため当該粒子を磁性流
体として利用すると２次凝集により粒子径が不揃いにな
り、均質な磁性流体を得ることができないおそれがある
という問題点を有していた。By the way, when the ultrafine particles produced by the conventional liquid phase method are dried to obtain the dried ultrafine particles, a strong surface tension due to the evaporation of water works, and thus monodispersed dry ultrafine particles cannot be obtained. It becomes a strong secondary aggregate. Further, even if water is replaced with alcohol or other non-aqueous solvent having a small surface tension and dried, agglomerated particles having a slightly smaller cohesive force than that of water can be obtained. Therefore, when the particles are used as a magnetic fluid, there is a problem that the particle diameters become uneven due to secondary aggregation, and a homogeneous magnetic fluid may not be obtained.
そこで、本発明は、この問題点を解決するためになされ
たものであり、液相法において再度の粉砕化等を必要と
せずに均質な磁性流体を提供することを目的としてなさ
れたものである。Therefore, the present invention has been made to solve this problem, and has been made for the purpose of providing a homogeneous magnetic fluid without the need for re-pulverization in the liquid phase method. .
本発明は、微粒子又は超微粒子として、非水溶性及び難
水溶性の含水酸化物、含水酸化物のヒドロゲルを生成
し、生成したヒドロゲルから共存する水溶性塩類を純水
で洗浄除去し、水溶性有機溶媒、又は混合有機溶媒によ
り、ヒドロゲル中の水を置換し、該有機溶媒又は該水を
高温高圧容器中で臨界温度の前後、又は超臨界温度、圧
力の範囲で保持した後に該有機溶媒または該水を除くこ
とにより得られた、粒子径が０．１μｍ以下で粒度分布
が０．１μｍから０．０１μｍまでの範囲に単分散した
磁性を帯びた超微粒子を界面活性剤を入れた液体に混ぜ
ることにより磁性流体を得るものである。INDUSTRIAL APPLICABILITY The present invention produces, as fine particles or ultrafine particles, hydrogels of water-insoluble and sparingly water-soluble oxides and hydroxides, and removes coexisting water-soluble salts from the produced hydrogel with pure water to remove water-soluble salts. Water in the hydrogel is replaced by an organic solvent or a mixed organic solvent, and the organic solvent or the water is held in the high-temperature high-pressure container before or after the critical temperature, or in the supercritical temperature or pressure range, and then the organic solvent or The magnetic ultrafine particles obtained by removing the water and having a particle diameter of 0.1 μm or less and a particle size distribution of 0.1 μm to 0.01 μm are dispersed in a liquid containing a surfactant. The magnetic fluid is obtained by mixing.
本発明において、粒子径が０．１μｍ以下で粒度分布が
０．１μｍから０．０１μｍまでの範囲に単分散した超
微粒子を液相法により得るには、まず、微粒子又は超微
粒子として生成した非水溶性及び難水溶性の含水酸化
物、含水水酸化物のヒドロゲルから共存する水溶性塩類
を除去する。すなわち、例えばFe2(SO4)3・１７H2O等の
水溶液にNH4OH等のアルカリ水溶液を加えて中性又は微
アルカリ性にしたときに非水溶性又は難水溶性の金属酸
化物又は金属水酸化物はヒドロゲルの状態で生成する。
このヒドロゲルから共存する水溶性塩類を純水にて洗浄
除去すれば高純度の金属酸化物又は金属水酸化物のヒド
ロゲルの水ペーストが得られる。この段階でできたもの
を乾燥しても単分散した乾燥超微粒子は得られず、利用
上再び粉砕を必要とするゴリゴリの粉体、塊体となるだ
けである。In the present invention, in order to obtain ultrafine particles having a particle size of 0.1 μm or less and a monodispersed particle size distribution in the range of 0.1 μm to 0.01 μm by the liquid phase method, first, fine particles or ultrafine particles produced Coexisting water-soluble salts are removed from hydrogels of water-soluble and slightly water-soluble hydroxides and hydroxides. That is, for example, a water-insoluble or slightly water-soluble metal oxide or metal when an alkaline aqueous solution such as NH 4 OH is added to an aqueous solution such as Fe 2 (SO 4 ) 3 · 17H 2 O to make it neutral or slightly alkaline Hydroxide is produced in the hydrogel state.
If water-soluble salts that coexist from this hydrogel are removed by washing with pure water, a high-purity hydrogel water paste of metal oxide or metal hydroxide can be obtained. Even if the product formed at this stage is dried, monodispersed dry ultrafine particles cannot be obtained, and it only becomes a rugged powder or lump that needs to be pulverized again for use.
そこで、次の段階として、エタノール又はメタノールな
どの水溶性有機溶媒でヒドロゲル中の水を置換するか又
はエタノール若しくはメタノールの一部をプロパノー
ル，ブタノールなどの難水溶性高級アルコールやグリセ
リンなどの多価アルコール又はアセトン，エーテル，ベ
ンゼン，ヘキサンなどの非水溶性有機溶媒で置換した嵌
合有機溶媒でヒドロゲル中の水を置換する。これによっ
て粒子径を０．０１μｍ前後又はこれ以下に迄粒子径を
抑えることができる。これは、水分が粒子径の成長に関
連し、その水分が少なくなるほど粒子径が抑制されるか
らである。すなわち、水分があると超々微粒子であるヒ
ドロゲルが溶解再結晶で成長したり、水中で合体成長す
るからである。ここで、ブチルアルコール，アミルアル
コール等の高級アルコールやアセトン，エーテルベンゼ
ン等の非水溶性、難水溶性有機溶媒はエタノールやメタ
ノールと混和し、そのとき一部水相に入りうるため、水
相における水酸化物ヒドロゲルや酸化物ヒドロゲルの水
相に対する溶解度は一層減少するので一層粒子径を小さ
くすることができる。Therefore, as the next step, the water in the hydrogel is replaced with a water-soluble organic solvent such as ethanol or methanol, or a part of ethanol or methanol is poorly water-soluble higher alcohol such as propanol or butanol, or a polyhydric alcohol such as glycerin. Alternatively, the water in the hydrogel is replaced with a fitting organic solvent replaced with a non-water-soluble organic solvent such as acetone, ether, benzene, or hexane. As a result, the particle size can be suppressed to about 0.01 μm or less. This is because the water content is associated with the growth of the particle size, and the smaller the water content, the more the particle size is suppressed. That is, when water is present, the hydrogel, which is ultra-fine particles, grows by dissolution and recrystallization, or coalesces and grows in water. Here, higher alcohols such as butyl alcohol and amyl alcohol, and water-insoluble and sparingly water-soluble organic solvents such as acetone and etherbenzene are miscible with ethanol and methanol, and at that time, some of them may enter the water phase. Since the solubility of the hydroxide hydrogel or the oxide hydrogel in the aqueous phase is further reduced, the particle diameter can be further reduced.
続いて、次の段階で、高温高圧容器中で使用した単一の
有機溶媒や混合有機溶媒のそれぞれの特有の臨界温度の
前後又は超臨界温度、圧力の範囲で保持した後に、有機
溶媒と固体とを分離して単分散で成熟した超微粒子を得
る。すなわち、超微粒子と有機溶媒とを分離するには有
機溶媒の蒸発除去が必要である。一般に超臨界状態の温
度圧力では、有機溶媒（又は水も同じ）は気体と液体と
の中間状態となり、極めて表面張力は減少する。この状
態で有機溶媒（又は水）を除くことによって粒子の凝集
を避け単分散した乾燥超微粒子が得られる。ここで、有
機溶媒は水への酸化物ヒドロゲル超々微粒子や水酸化物
ヒドロゲル超々微粒子の溶解を妨害し、合体成長を防
ぐ。さらに高温状態は超微粒子の結晶格子形成を防ぐ。
すなわち、高温ほど超微粒子の形成に都合がよいが、高
温になるに従い圧力も大となるため、材料に限界が生
じ、約４００℃、約４００気圧が最高となる。ただし、
超臨界での圧力は内容物の体積に左右されるので、温度
を上げても内容物の量を減ずれば圧力は大きくならない
が、得られる超微粒子の量は少なくなる。Then, in the next step, before and after the critical temperature peculiar to each of the single organic solvent and the mixed organic solvent used in the high-temperature high-pressure container or the supercritical temperature, after being maintained in the range of pressure, the organic solvent and the solid And are separated to obtain monodisperse and mature ultrafine particles. That is, it is necessary to remove the organic solvent by evaporation in order to separate the ultrafine particles and the organic solvent. Generally, at the temperature and pressure of the supercritical state, the organic solvent (or water is the same) is in an intermediate state between gas and liquid, and the surface tension is extremely reduced. By removing the organic solvent (or water) in this state, monodispersed dry ultrafine particles are obtained while avoiding particle aggregation. Here, the organic solvent hinders the dissolution of the oxide hydrogel ultrafine particles and the hydroxide hydrogel ultrafine particles in water, and prevents coalescence growth. Furthermore, the high temperature state prevents the formation of crystal lattice of ultrafine particles.
That is, the higher the temperature, the more convenient the formation of ultrafine particles, but the higher the temperature, the higher the pressure. Therefore, the material is limited, and the maximum temperature is about 400 ° C. and about 400 atm. However,
Since the pressure at the supercritical level depends on the volume of the contents, the pressure does not increase even if the temperature is increased and the amount of the contents is decreased, but the amount of ultrafine particles obtained is small.
本発明は、このようにして得られた単分散した磁性を帯
びた超微粒子を磁性流体として利用する。すなわち、当
該超微粒子を界面活性剤を入れた水若しくは有機溶媒等
の液体に混ぜて磁性流体を得る。The present invention utilizes the monodisperse magnetic ultrafine particles thus obtained as a magnetic fluid. That is, the ultrafine particles are mixed with a liquid such as water or an organic solvent containing a surfactant to obtain a magnetic fluid.
次に本発明に係る実施例を説明する。第１の実施例はマ
グネタイト（Fe3O4）を磁性流体に利用したものであ
る。単分散のマグネタイト（Fe2O3）の超微粒子を得る
には、まず硫酸第一鉄結晶（FeSO4 ７H2O）３３３．６
ｇと硫酸第二鉄結晶（Fe2 SO4 317H2O）３４８ｇを熱純水
（７０〜９０℃）２．４に溶解する。これに苛性ソー
ダ７２０ｇを純水３に溶解した溶液をよく撹拌しつつ
添加し、マグネタイト（FeO・Fe2O3）の超々微粒子を含
むゲル（第５図（１）に示す）を作る。これを濾過し熱
純水（７０〜９０℃）４０でNa+,SO4 =イオンの殆んど
なくなる迄洗浄する。洗浄後えられるケーキの含水量は
２５％位となる。このケーキにエタノール７を加え、
ミキサーでよく混合しマグネタイトゲル超々微粒子をエ
タノール中に均一に分散させる。ここで８のアルコー
ルスラリーがえられる。Next, examples according to the present invention will be described. The first embodiment uses magnetite (Fe 3 O 4 ) as a magnetic fluid. To obtain ultrafine particles of monodisperse magnetite (Fe 2 O 3 ), first, ferrous sulfate crystal (FeSO 4 7H 2 O) 333.6 is used.
g and 348 g of ferric sulfate crystals (Fe 2 SO 4 3 17H 2 O) are dissolved in 2.4 of hot pure water (70 to 90 ° C.). A solution prepared by dissolving 720 g of caustic soda in pure water 3 is added to the mixture with good stirring to form a gel containing ultrafine particles of magnetite (FeO.Fe 2 O 3 ) (shown in FIG. 5 (1)). This is filtered and washed with hot pure water (70 to 90 ° C.) 40 until almost no Na + , SO 4 = ions are present. The water content of the cake obtained after washing is about 25%. Add ethanol 7 to this cake,
Mix well with a mixer to evenly disperse the ultrafine particles of magnetite gel in ethanol. Here an alcohol slurry of 8 is obtained.
このアルコールスラリー３をとり、５の内容積をも
つオートクレーブに入れ、２８０℃に加熱する。圧力は
１５０気圧になる。１時間保持迄エタノールを除去して
単分散したマグネタイトの超微粒子を含む乾燥超微粉末
１７０ｇがえられる。このマグネタイト超微粒子の磁気
的性質は 飽和磁化 ５８．６emu／ｇ 残留磁化 ６．４１emu／ｇ 保持力 ３３．１rsted マグネタイトゲル及びオートクレーブ処理后のマグネタ
イト結晶のＸ線回折図は第１図及びマグネタイト結晶は
第４図の（１）に示す。This alcohol slurry 3 is taken and placed in an autoclave having an internal volume of 5, and heated to 280 ° C. The pressure becomes 150 atm. 170 g of dry ultrafine powder containing ultrafine particles of magnetite monodispersed by removing ethanol until 1 hour is obtained. The magnetic properties of these ultrafine magnetite particles are: saturation magnetization 58.6emu / g remanent magnetization 6.41emu / g coercive force 33.1rsted X-ray diffraction diagram of magnetite crystal after magnetite gel and autoclave treatment is shown in Fig. 1 and magnetite crystal is It is shown in (1) of FIG.
本実施例に係るマグネタイトの超微粒子の粒形は球状で
粒子径は約０．０３μｍから０．１μｍまでの範囲にあ
る。The ultrafine particles of magnetite according to this example have a spherical particle shape and a particle diameter in the range of about 0.03 μm to 0.1 μm.
次に第２の実施例はマンガン亜鉛フェライトの超微粒子
を磁性流体に利用したものである。単分散のマンガン亜
鉛フェライトの超微粒子を得るには、塩化亜鉛（ZnC
l2）２１７ｇ，塩化マンガン（MnCl2）２０２ｇ及び三
塩化鉄（FeCl3）５２４ｇを純水１０に溶解する。こ
の溶液を撹拌しつつ、アンモニアガス（NH3）２７３ｇ
を加える。アンモニアガスの吹込みの終ったあと、生成
したマンガン亜鉛フェライトのヒドロゲルは第５図の
（２）に示すように数十Å以下の判別し難いほどの超々
微粒子である。このスラリーを濾過し、熱純水８０で
洗滌する。洗滌によって完全にNH4 +，Cl-イオンを除去
したのち、ケーキ中の水分をできるだけ吸引、濾過した
のち、７のメチルアルコールを加え、ミキサーでゲル
をメチルアルコール中に均一に分散させたのちこのスラ
リー３を採取して内容積５のオートクレーブに入れ
て３００℃に加熱する。圧力は２００気圧に達する。６
時間保持したのちメチルアルコールを除去する。えられ
たマンガン亜鉛フェライトの超微粒子は第４図（２）に
示すように１００Å以下の超微粒子で乾燥超微粉末とし
て１８８ｇがえられる。第２図及び第３図は非品質のヒ
ドロゲルと処理后の結晶のＸ線回折図を示す。尚、以上
の実施例において、生成された磁性流体中にインク組成
物を加えることにより、磁性インクとして利用すること
もできる。磁性インクは、一種の磁性流体であり自動改
札器用切符、銀行預金通帳やカード等の自動読み取り器
用に使用される。前述したように、本実施例により生成
された単分散の磁性を帯びた超微粒子を用いると、均質
な磁気インクが製造できるため、膜厚を均一にすること
ができて平滑性のある磁気インクを提供することができ
る。Next, the second embodiment uses ultrafine particles of manganese zinc ferrite as a magnetic fluid. To obtain ultrafine particles of monodisperse manganese zinc ferrite, zinc chloride (ZnC
l 2 ) 217 g, manganese chloride (MnCl 2 ) 202 g and iron trichloride (FeCl 3 ) 524 g are dissolved in pure water 10. While stirring this solution, 273 g of ammonia gas (NH 3 )
Add. After the blowing of the ammonia gas was completed, the hydrogel of the manganese-zinc ferrite produced was ultra-fine particles of tens of liters or less, which were hard to distinguish, as shown in (2) of FIG. The slurry is filtered and washed with hot pure water 80. After completely removing NH 4 + , Cl − ions by washing, suction the water in the cake as much as possible, filter, then add methyl alcohol 7 and disperse the gel evenly in methyl alcohol with a mixer. The slurry 3 is sampled, placed in an autoclave having an internal volume of 5 and heated to 300 ° C. The pressure reaches 200 atm. 6
After holding for a time, methyl alcohol is removed. The obtained ultrafine particles of manganese zinc ferrite are ultrafine particles of 100 Å or less as shown in Fig. 4 (2), and 188 g of dry ultrafine powder is obtained. 2 and 3 show the X-ray diffractograms of the inferior hydrogel and the treated crystals. In addition, in the above examples, the ink composition may be added to the produced magnetic fluid to be used as a magnetic ink. Magnetic ink is a kind of magnetic fluid and is used for automatic ticket gates, automatic readers for bank passbooks and cards. As described above, when the monodisperse magnetic ultrafine particles produced according to the present embodiment are used, a homogeneous magnetic ink can be produced, so that the magnetic ink having a uniform film thickness and smoothness can be produced. Can be provided.
本発明では磁性流体の材料に単分散した磁性を帯びた超
微粒子を利用している。そのため、当該超微粒子は２次
凝集することがないので、均質な磁性流体を得ることが
できる。In the present invention, ultrafine particles having magnetism monodispersed in the material of the magnetic fluid are used. Therefore, since the ultrafine particles do not secondarily aggregate, a homogeneous magnetic fluid can be obtained.
また、本発明では、臨界温度の前後、又は超臨界温度、
圧力で有機溶媒又は水を除くことにより凝集のない磁性
流体を得るようにしているので、煩雑な分散工程を経由
することなく、かつ、超微粒子の結晶格子の形成を防止
することができる。Further, in the present invention, before and after the critical temperature, or supercritical temperature,
Since the magnetic fluid without aggregation is obtained by removing the organic solvent or water under pressure, it is possible to prevent the formation of the crystal lattice of the ultrafine particles without going through a complicated dispersion process.
第１図はマグネタイトのＸ線回折図、第２図はMn−Zn−
フェライトゲル状態のＸ線回折図、第３図はMn−Zn−フ
ェライトゲルの本実施例処理後の状態を示すＸ線回折
図、第４図はマグネタイト及びMn−Zn−フェライトの粒
子構造を示す電子顕微鏡拡大写真、第５図はマグネタイ
トゲル及びMn−Zn−フェライトゲルの粒子構造を示す電
子顕微鏡拡大写真である。Figure 1 is an X-ray diffraction diagram of magnetite, and Figure 2 is Mn-Zn-
X-ray diffraction diagram of ferrite gel state, FIG. 3 is an X-ray diffraction diagram showing the state of Mn-Zn-ferrite gel after the treatment of this example, and FIG. 4 shows the particle structure of magnetite and Mn-Zn-ferrite. An electron microscope enlarged photograph, FIG. 5 is an electron microscope enlarged photograph showing the particle structures of magnetite gel and Mn-Zn-ferrite gel.
Claims (2)
難水溶性の含水酸化物、含水酸化物のヒドロゲルを生成
し、生成したヒドロゲルから共存する水溶性塩類を純水
で洗浄除去し、水溶性有機溶媒、又は混合有機溶媒によ
り、ヒドロゲル中の水を置換し、該有機溶媒又は該水を
高温高圧容器中で臨界温度の前後、又は超臨界温度、圧
力の範囲で保持した後に該有機溶媒または該水を除くこ
とにより得られた、粒子径が０．１μｍ以下で粒度分布
が０．１μｍから０．０１μｍまでの範囲に単分散した
磁性を帯びた超微粒子を界面活性剤を入れた液体に混ぜ
ることを特徴とする磁性流体の製造方法。1. A water-soluble or slightly water-soluble hydrogel of hydrous oxide or hydrous oxide is produced as fine particles or ultrafine particles, and water-soluble salts coexisting from the produced hydrogel are removed by washing with pure water. Water in the hydrogel is replaced by a water-soluble organic solvent or a mixed organic solvent, and the organic solvent or the water is held in the high-temperature high-pressure container before or after the critical temperature, or in the supercritical temperature or pressure range, and then the organic solvent. Alternatively, a liquid containing a surfactant containing magnetic ultrafine particles obtained by removing the water and having a particle size of 0.1 μm or less and a particle size distribution monodispersed in the range of 0.1 μm to 0.01 μm. A method for producing a magnetic fluid, characterized in that the magnetic fluid is mixed with.
０．１μｍから０．０１μｍまでの範囲に単分散した磁
性を帯びた超微粒子として、マグネタイト（Fe3O4）等
の酸化鉄、及びマンガン亜鉛フェライト（MnO-ZnO-Fe2O
3）を用いたことを特徴とする特許請求の範囲第１項記
載の磁性流体の製造方法。2. Iron oxide such as magnetite (Fe 3 O 4 ) as magnetic ultrafine particles monodispersed in the range of 0.1 μm to 0.01 μm with a particle size of 0.1 μm or less. , And manganese zinc ferrite (MnO-ZnO-Fe 2 O
3 ) The method for producing a magnetic fluid according to claim 1, characterized in that
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61039597A JPH061728B2 (en) | 1986-02-25 | 1986-02-25 | Magnetic fluid manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61039597A JPH061728B2 (en) | 1986-02-25 | 1986-02-25 | Magnetic fluid manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62198104A JPS62198104A (en) | 1987-09-01 |
| JPH061728B2 true JPH061728B2 (en) | 1994-01-05 |
Family
ID=12557518
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61039597A Expired - Lifetime JPH061728B2 (en) | 1986-02-25 | 1986-02-25 | Magnetic fluid manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH061728B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108101527A (en) * | 2017-12-07 | 2018-06-01 | 天长市昭田磁电科技有限公司 | A kind of high frequency fine grain soft magnetic ferrite and preparation method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5440069B2 (en) * | 1975-03-27 | 1979-12-01 | ||
| JPS5868906A (en) * | 1981-10-21 | 1983-04-25 | Matsushita Electric Ind Co Ltd | Magnetic fluid |
| JPS59105093A (en) * | 1982-12-08 | 1984-06-18 | Nippon Seiko Kk | Magnetic fluid composition and its preparation |
-
1986
- 1986-02-25 JP JP61039597A patent/JPH061728B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108101527A (en) * | 2017-12-07 | 2018-06-01 | 天长市昭田磁电科技有限公司 | A kind of high frequency fine grain soft magnetic ferrite and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62198104A (en) | 1987-09-01 |
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