JPS62128103A - Manufacture of magnetic fluid - Google Patents

Abstract

PURPOSE:To obtain high magnetizing force at high concentration together with effective formation, by performing reactions of concurrent or arbitrarily ordered addition of ferrous salt and ferric salt to a mixture of alkali hydroxide or ammonium hydroxide and organic acid and/or its salt in existence of an organic solvent. CONSTITUTION:Colloid of ferromagnetic iron oxide is produced and dispersed in an organic solvent. Solvents of natural or synthetic hydrocarbon such as aliphatic group hydrocarbon and aromatic group one are cited as organic solvents. And, (A) either alkali hydroxide or ammonium hydroxide or both, (B) organic acid such as organic carboxylic acid or organic sulfonic acid or its salt, and (C) ferrous salt and ferric salt are mixed for reaction in the solvent. Ferrous salt and ferric salt of sulfate, nitrate, hydrochloride, ammonium sulfate, and their hydrate are cited as the abovementioned ferrous salt and ferric salt.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、有機溶媒中に強磁性酸化鉄コロイド粒子を高
濃度で分散させた磁性流体の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a magnetic fluid in which ferromagnetic iron oxide colloidal particles are dispersed at a high concentration in an organic solvent.

磁性流体は、フェライト等の含鉄酸化物、あるいハ鉄、
コバルト、鉄−コバルト合金等の金属のコロイドサイズ
の強磁性粒子を界面活性剤で吸着処理して液体中に分散
させた懸濁液である。通常の懸濁液とは異なり、極めて
分散性が良いために磁力、遠心力、重力などの作用に対
して固液分離を起さず、常に均一な磁化の機能を有し、
しかも液体としての挙動を示すという特性を有する。The magnetic fluid is made of iron-containing oxides such as ferrite, or
This is a suspension in which colloid-sized ferromagnetic particles of metal such as cobalt or iron-cobalt alloy are adsorbed with a surfactant and dispersed in a liquid. Unlike ordinary suspensions, it has extremely good dispersibility, so it does not undergo solid-liquid separation under the effects of magnetic force, centrifugal force, gravity, etc., and always has a uniform magnetization function.
Moreover, it has the characteristic of exhibiting behavior as a liquid.

この特異な性質を利用して、シーリング剤、ダンピング
剤、磁気インク、比重差選別装置等多岐にわたり用いら
れている。また最近では、ディスプレイ、偏光子、元フ
ァイバー接続装置等の光応用技術、めるいを１他の広範
囲な用途開発が進められつつあり、非常に注目されてい
る。Utilizing this unique property, it is used in a wide variety of applications, including sealing agents, damping agents, magnetic inks, and specific gravity separation devices. Recently, the development of optical application technologies such as displays, polarizers, fiber connection devices, and a wide range of other uses has been progressing, and has attracted much attention.

〔従来の技術〕[Conventional technology]

従来の磁性流体の製法は、水系で先ず強磁性酸化物を製
し、その微粉末を分離（乾燥）した後、こｔを水系又は
有機溶媒系に分散化させる方法でめった。その分散化法
は、化学的反応を用いる方法と物理的方法で微粒子化し
て分散化する方法がとられていた。これら公知の方法と
しては、 特開昭５１−　２２６８８号公報 ＩＩ　　５１−　４４５７９　　ｔｔ Ｉ／　　　５１−　　４４５８０　　　　＃／／　　５
２−　　７８２　　ｇ ｌｌ　　　　５３−　　１３４３７　　　　ｐｔｔ　　
　　５２−　　４２４８２　　　　／／／／　５２−１
２５４７９　　ｓ ｔｔ　　５４−　６５１８２　　ＩＩ ／ｌ　　　　５６−１１８４９６　　　　ｔｔ／／　　
５６−１５２８８ｏ　　ｚ ｌ　　　　５７−１３２３０３　　　　ｔｔ１／　　　
　５８−１７４４９５　　　　ｔｔ／／　　　　５８−
１８０５９６　　　　ｇ＃　　　　５９−１０５（Ｊ９
３　　　　Ｎ１　５９−１６８０９７　　ｔｔ 特開昭６０−　５８４９７号公報 米国特許第３２１５５７２号公報 等に記載され友ものが挙げられる。The conventional method for producing magnetic fluids is to first produce a ferromagnetic oxide in an aqueous system, separate (dry) its fine powder, and then disperse it in an aqueous or organic solvent system. The dispersion methods used include a method using a chemical reaction and a method of forming fine particles and dispersing them using a physical method. These known methods include JP-A No. 51-22688 II 51-44579 tt I/ 51-44580 #// 5
2- 782 g ll 53- 13437 ptt
52- 42482 //// 52-1
25479 s tt 54- 65182 II /l 56-118496 tt//
56-15288oz l 57-132303 tt1/
58-174495 tt // 58-
180596 g# 59-105 (J9
3 N1 59-168097 tt JP-A-60-58497 Publication U.S. Pat.

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

これらの方法の欠点として、物理的微粉砕法による場合
は長時間を要すること、化学的微粉化法でも、従来法で
はマグネタイトコロイド生成工程、界面活性剤による吸
着工程、−調整・凝集沈降工程、洗浄工程、脱水・乾燥
工程、油中分散工程、遠心分離工程と非常に多くの工程
を経て製するため全体として長時間を要し、極めて効率
が悪く工業的製法とはいえなかった。The disadvantages of these methods are that physical pulverization requires a long time, and even with chemical pulverization, conventional methods require a magnetite colloid generation step, an adsorption step using a surfactant, a conditioning/coagulation sedimentation step, The process involved a large number of steps, including a washing process, a dehydration/drying process, a dispersion process in oil, and a centrifugation process, so it took a long time overall, and was extremely inefficient and could not be called an industrial process.

〔問題全解決する友めの手段〕[Friendly means to solve all problems]

本発明者らは、このような従来法の欠点に鑑み、効率の
艮い、又高濃度で高磁化力を有する工業的な磁性流体の
製法について鋭意研究を重ね、本発明を完成した。In view of the shortcomings of the conventional methods, the present inventors have completed the present invention by conducting intensive research on methods for producing industrial magnetic fluids that are highly efficient and have high concentration and high magnetizing power.

即ち、本発明は、有機溶媒中で、強磁性酸化鉄コロイド
を生成せしめ分散化する方法でろって、有機溶媒の存在
下１次の４要素の全てを適宜選択された順で混合し反応
させることを特徴とする磁性流体の製造方法である。That is, the present invention is a method in which a ferromagnetic iron oxide colloid is produced and dispersed in an organic solvent, and all four primary elements are mixed and reacted in an appropriately selected order in the presence of an organic solvent. This is a method for producing a magnetic fluid characterized by the following.

（１）　　水酸化アルカリ及び／又は水酸化アンモニウ
ム （２）有機酸及び／又はその塩 （３ン　第一鉄塩 （４）第二鉄塩 更に好適な実施方法としては、有機溶媒の存在下で、水
酸化アルカリ又は水酸化アンモニウムと有機酸及び／又
はその塩との混合物に第−鉄塩及び第二鉄塩を同時に又
は任意の順で加えて反応させる方法でおる。(1) Alkali hydroxide and/or ammonium hydroxide (2) Organic acid and/or its salt (3) Ferrous salt (4) Ferric salt As a more preferred method of implementation, in the presence of an organic solvent , a method in which a ferric salt and a ferric salt are added simultaneously or in any order to a mixture of alkali hydroxide or ammonium hydroxide and an organic acid and/or its salt and reacted.

本発明で用いられる有・融溶媒は、特に限定されるもの
ではなく、一般に用いられる有機溶媒を用いることがで
きるが、天然又を工合成の炭化水素系溶媒がよく用いら
れる。例えば、脂肪族系及び芳香族系炭化水素、軽油、
灯油、鉱油、オレフィン重合油等が革げられる。The organic or molten solvent used in the present invention is not particularly limited, and commonly used organic solvents can be used, but natural or synthetic hydrocarbon solvents are often used. For example, aliphatic and aromatic hydrocarbons, light oil,
Kerosene, mineral oil, olefin polymerized oil, etc. can be extracted.

本発明で用いられる水酸化アルカリは、例えは、水酸化
ナトリウム、水酸化カリウム等を挙げることができる。Examples of the alkali hydroxide used in the present invention include sodium hydroxide and potassium hydroxide.

ま九本発明では、水酸化アルカリ及び水酸化アンモニウ
ムのどちらか又は両者を用いることができ、好適には水
酸化アンモニウムである。(9) In the present invention, either or both of alkali hydroxide and ammonium hydroxide can be used, and ammonium hydroxide is preferred.

本発明で用いられる有機酸は、有機カルボン酸、有機ス
ルホン酸を特に限定なく挙げることができ、有機カルボ
ン酸は好ましくは、アルケニルカルメン酸、ナフテン酸
等を挙げることが出来、アルケニルカルボン酸としては
、炭素数１１〜２２個のアルケニルカルメン酸を挙げる
ことができその例としては、オレイン酸、リノール酸、
リルン酸、リシノール酸、エルカ酸、ドデセニルコＩ・
り酸を挙げることができる。有機スルホン酸は、例えば
、石油スルホン酸、モノ又はジアルキルベンゼンスルホ
ン酸ヲ挙げることができ、石油スルホン酸（工市販の物
を使用でき、モノ又はジアルキルベンゼンスルホ／酸Ｇ
’！、　例、ｔｔｄ’、　　）’デシルベンゼンスルホ
ン酸、シドデシルペンゼ／スルホン酸等を挙げることが
できる。The organic acids used in the present invention can include organic carboxylic acids and organic sulfonic acids without particular limitation, and the organic carboxylic acids can preferably include alkenylcarmenic acids, naphthenic acids, etc., and the alkenylcarboxylic acids include , alkenylcarmenic acids having 11 to 22 carbon atoms, examples of which include oleic acid, linoleic acid,
Rilunic acid, ricinoleic acid, erucic acid, dodecenyl co-I.
Examples include phosphoric acid. Examples of the organic sulfonic acid include petroleum sulfonic acid, mono- or dialkylbenzene sulfonic acid, petroleum sulfonic acid (commercially available products can be used,
'! Examples include ttd', )'decylbenzenesulfonic acid, cydecylpenze/sulfonic acid, and the like.

本発明で用いられる有機酸塩は、上述の有機酸の金属塩
であり、その金属としては、周期律表第１族、第■族、
第■族、第■族及び第１族の金属を挙げることができ、
好ましくは、Ｌｌ。The organic acid salt used in the present invention is a metal salt of the above-mentioned organic acid.
Mention may be made of metals of Groups ■, Groups ■ and Groups 1;
Preferably Ll.

Ｎａ　ｌ　Ｋ　Ｉ　Ｍｇ　ｌ　ｃａ　＃　Ｓｒ　、　Ｂ
ａ　、　Ｚｎ　、　Ｍｏ　、　Ｍｎ　＃　Ｆｅ。Na l KI Mg l ca # Sr, B
a, Zn, Mo, Mn#Fe.

Ｃｏ　＋　Ｎｉ等を挙けることができる。Examples include Co+Ni.

本発明で用いられる第−鉄塩及び第二鉄塩は一般に市販
されているものを使用でき、特に限定はないが、例えば
、第−鉄及び第二鉄の硫酸塩、硝酸塩、塩酸塩及び硫酸
アンモニウム塩並びにこれらの水和物を挙げることがで
きる。それらの具体例として、硫酸第一鉄、硝酸第一鉄
、塩化第一鉄、硫酸第一鉄アンモニウム、硫酸第二鉄、
硝酸第二鉄、塩化第二鉄、硫酸第二鉄アンモニウム、あ
るいはこれらの水和物等でらる。Generally commercially available ferrous salts and ferric salts used in the present invention can be used, and there are no particular limitations, such as ferric and ferric sulfates, nitrates, hydrochlorides and ammonium sulfates. Mention may be made of salts as well as hydrates thereof. Specific examples thereof include ferrous sulfate, ferrous nitrate, ferrous chloride, ferrous ammonium sulfate, ferric sulfate,
Ferric nitrate, ferric chloride, ferric ammonium sulfate, or their hydrates.

本発明で用いられる水酸化アルカリ又は水酸化アンモニ
ウムの添加量を工、第−鉄塩及び第二鉄塩の酸化物化に
要する理論量よりも若干過剰ニ加工、ｐＨは８以上にな
ることが好ましい。−８未満では高磁化力を有する磁性
流体を得ることが難しい。It is preferable that the amount of alkali hydroxide or ammonium hydroxide used in the present invention be slightly excessive than the theoretical amount required for converting the ferrous salt and ferric salt into oxides, and the pH will be 8 or higher. . If it is less than -8, it is difficult to obtain a magnetic fluid with high magnetizing force.

本発明で用いられる有機酸及びその塩の添加量は、生成
するべき酸化鉄１００！量部に対して５〜８０重量部が
好ましく、２０〜５０重量部が特に好ましい。５重ｉｋ
部禾満では高濃度の酸化鉄の分散性が悪くなり、８０重
量部を超えると、製品の粘度が高くなったり、鉄含有量
が少なくなるので好ましくない。The amount of the organic acid and its salt used in the present invention is 100% of the iron oxide to be produced! It is preferably 5 to 80 parts by weight, particularly preferably 20 to 50 parts by weight. quintuple ik
If the content is less than 80 parts by weight, the dispersibility of high-concentration iron oxide will deteriorate, and if it exceeds 80 parts by weight, the viscosity of the product will increase and the iron content will decrease, which is not preferable.

本発明で用いられる第一鉄塩と、第二鉄塩の併用割合は
、特に限定されるものではないが、それら鉄塩に含まれ
る第一鉄イオンと第二鉄イオンのモル比が１＝４〜２二
１の範囲が優れた磁化力を示し好適である。The combined ratio of the ferrous salt and ferric salt used in the present invention is not particularly limited, but the molar ratio of ferrous ions to ferric ions contained in these iron salts is 1 = The range of 4 to 221 shows excellent magnetizing power and is suitable.

又、第−鉄塩及び第二鉄塩の添加方法は、第一鉄塩を入
れて反応させ几後、第二鉄塩を入れて反応させる方法、
あるいは第一鉄塩と第二鉄塩を逆の順序とする方法、又
は両者を同時に添加して反応させる方法のいずれの方法
もとることができる。Further, the method for adding ferrous salts and ferric salts is to add ferrous salt and react, then add ferric salt and react;
Alternatively, it is possible to use either a method in which the ferrous salt and ferric salt are added in the reverse order, or a method in which they are added simultaneously and reacted.

但し、水酸化アルカリ又は水酸化アンモニウムを第−鉄
塩及び第二鉄塩に添加する方法では生成する磁性流体に
ついて、磁化力の低いものが得られる傾向にある。However, the method of adding alkali hydroxide or ammonium hydroxide to ferrous salt and ferric salt tends to produce a magnetic fluid with low magnetizing power.

第一鉄塩と第二鉄塩の添加速度は、特に限定はないが、
一度に大量に添加すると、液の温度、粘度が上昇し制御
しにくくなることがあるので徐々に添加する方が好まし
い。There is no particular limitation on the addition rate of ferrous salt and ferric salt, but
If a large amount is added at once, the temperature and viscosity of the liquid may rise and become difficult to control, so it is preferable to add it gradually.

第一鉄塩と第二鉄基金添加するときの温度は、特に限定
はないが、使用する有機溶媒及び水酸化アルカリの穐類
に応じて適宜変災される。例えば、ｎ−ヘキサン（ｂ、
ｐ、６８７℃）の工うな低沸点有機溶媒を用い友時は、
６０℃程度以下で添加することが好ましく、また水酸化
アンモニウムのようなアルカリを用いた時は、揮発し易
いため、５０℃以下で添加する方が好ましい。The temperature at which the ferrous salt and ferric salt are added is not particularly limited, but may be varied as appropriate depending on the organic solvent and alkali hydroxide used. For example, n-hexane (b,
p, 687°C) using a low boiling point organic solvent,
It is preferable to add at about 60° C. or lower, and when an alkali such as ammonium hydroxide is used, it is preferably added at 50° C. or lower because it easily volatizes.

最も好ましくは２５〜４５℃位である。The temperature is most preferably about 25 to 45°C.

本発明で用いられる有機酸及び／又はその基金添加し、
熟成するときの温度は、特に限定はないが、使用する溶
媒に応じて適宜法められ、２５〜４５℃位の場合は充分
熟成時間をとる方がよく、あるいはそれより熟成温度を
上げて短時間の熟成を行なうことも工く、後者の場合、
６０〜８５℃位が好ましい。Adding the organic acid and/or its base used in the present invention,
The temperature for ripening is not particularly limited, but it is determined as appropriate depending on the solvent used. If the temperature is around 25 to 45 degrees Celsius, it is better to allow sufficient ripening time, or to shorten the temperature by raising the temperature. In the latter case, it is also possible to ripen over time.
The temperature is preferably about 60 to 85°C.

本発明で用いられる有機溶媒は、必要に応じて低沸点有
機溶媒を高沸点有機溶媒に、工程の途中で置換すること
ができる。In the organic solvent used in the present invention, a low boiling point organic solvent can be replaced with a high boiling point organic solvent during the process, if necessary.

反応系中に、水を存在させてもさせなくてもよいが、水
酸化アルカリ又は第−鉄塩及び／又は第二鉄塩を均一な
水：ｍ′ｌｅｉ、とじて存在さぞる方が、より微粒子の
酸化鉄を得ることができるので、好ましく　ｈｉ水を所
望量使用する方がよい。Water may or may not be present in the reaction system, but it is better to mix the alkali hydroxide or ferric salt and/or ferric salt with homogeneous water (m'lei). It is preferable to use the desired amount of hi water, since finer particles of iron oxide can be obtained.

水を使用して反応を進行させ几場合、副生ずる無機塩類
は水層に溶解するがこれを除去する方法としては、分液
により水層を除く方法が一般的であり、分液不良の場合
は遠心分離にＬり分液し易くして水層を除去する方法等
がおり、爽に十分に脱水する場合、低沸点有機溶媒を用
いて共沸脱水する方法が工く行なわれ、これらの方法に
よって十分に脱水を行なうことが好ましい。When the reaction is carried out using water, the by-product inorganic salts dissolve in the aqueous layer, but the common method for removing this is to remove the aqueous layer by liquid separation. There are methods to remove the aqueous layer by centrifugation to make it easier to separate the liquid, and for sufficient dehydration, azeotropic dehydration using a low-boiling organic solvent is used. It is preferable to perform sufficient dehydration by this method.

また、製品中に無機塩類や酸化鉄コロイド粒子の太きい
ものが存在すると分散安定性が不光分で、沈降する原因
ともなるので、濾過や遠心分離等の方法により十分それ
らを除去しておくことが好ましい。Additionally, if there are large inorganic salts or iron oxide colloid particles in the product, the dispersion stability will be poor and may cause sedimentation, so these should be thoroughly removed by methods such as filtration or centrifugation. is preferred.

〔実施例及び効果〕[Examples and effects]

以下、実施例によって本発明を更に具体的に説明するが
、本発明はこれらによって限定されるものではない。EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

実施例１ 第−鉄塩及び第二鉄塩の併用割合を第一鉄イオンと第二
鉄イオンのモル比で１＝２となるように調製し、有機溶
媒にトルエン、有機酸塩にオレイン酸ナトリウムを用い
た磁性流体の作製。Example 1 The combined ratio of ferrous salts and ferric salts was adjusted so that the molar ratio of ferrous ions to ferric ions was 1=2, and toluene was used as the organic solvent and oleic acid was used as the organic acid salt. Preparation of magnetic fluid using sodium.

５！の四日フラスコを用い、水４Ｏｒ、）ルエン１６０
０ｒ、水酸化ナトリウム１４．Ｏｆ　（０，３４９モル
）を順次加え、攪拌しながらオレイン酸９６ｒ（０，３
４９モル）を添加し、液温を７５〜ｓｏ℃に保ちながら
３０分間攪拌するとオレイン酸ナトリウムを含むエマル
ションとなった。次に、液温を３５℃に下げ、２８％ア
ンモニア水５３４．３ｔ（８，８モル）を加えて攪拌混
合し、均一なエマルションを得友。5! Using a four-day flask, add 4 Or of water,) 160 of luene.
0r, sodium hydroxide 14. Of (0,349 mol) was added sequentially and oleic acid 96r (0,3 mol) was added with stirring.
49 mol) was added thereto and stirred for 30 minutes while maintaining the liquid temperature at 75-so° C., resulting in an emulsion containing sodium oleate. Next, the liquid temperature was lowered to 35°C, and 534.3 t (8.8 mol) of 28% aqueous ammonia was added and mixed with stirring to obtain a uniform emulsion.

別にあらかじめ硫酸第１鉄７水塩２７８ｒ（１モル）、
硫酸第２鉄６水塩５０８ｆ（１モル）、水１１２５ｆの
混合水溶液を調製しておき、この鉄塩水溶液を前記のエ
マルジョン中に滴下し、マグネタイトコロイドの生成及
び吸着処理全行つｔ、鉄塩水溶液の滴下は２時間を要し
、液温は滴下直前の３０℃から終了時４０℃に上昇し友
０滴下終了時点で反応液は、黒色の分散液となった九め
、液温を７５〜８０℃により、３０分間攪拌・熟成し念
、この後、５Ｊの分液ロートに移し、静置し九。約５分
経過すると、上層にマグネタイトコロイドが分散し几ト
ルエン層が、下層に無機塩を含んだ水層が明瞭に分離し
たので、下層を排出除去し友。この廃水ｔｚｐＨ９であ
った。Separately, ferrous sulfate heptahydrate 278r (1 mol),
A mixed aqueous solution of 508f (1 mol) of ferric sulfate hexahydrate and 1125f of water is prepared in advance, and this iron salt aqueous solution is dropped into the above emulsion to perform all the magnetite colloid generation and adsorption treatments. Dropping of the salt aqueous solution took 2 hours, and the temperature of the solution rose from 30°C just before the dropping to 40°C at the end.At the end of the dropping, the reaction liquid became a black dispersion. Stir and ripen at 75-80°C for 30 minutes, then transfer to a 5J separatory funnel and let stand. After about 5 minutes, the magnetite colloid was dispersed in the upper layer and a toluene layer was clearly separated, and the lower layer was clearly separated into an aqueous layer containing inorganic salts, so the lower layer was drained and removed. This wastewater tz pH was 9.

とのマグネタイトコロイドが分散したトルエン層は、再
び５！の四日フラスコに移され、わずかに含まれる水分
を完全に除去する几めに、トルエンとの共沸脱水を行つ
九。The toluene layer in which the magnetite colloid is dispersed is 5 again! After four days, the mixture was transferred to a flask and subjected to azeotropic dehydration with toluene to completely remove the small amount of water present.

次に、このトルエンのマグネタイトコロイド分散液は、
高速遠心機を用い、８０００ｘａの遠心力下で２０分間
遠心分離を行つ九。この操作により非分散固形物は取り
除かれ、トルエンを分散媒とし友極めて安定なマグネタ
イトコロイド分散液１８３０Ｐが得られた。この分散液
は、加熱されながら減圧濃縮され、濃ｍｇ、が５００？
となつ友時点で濃縮を終了し几。Next, this toluene magnetite colloid dispersion is
Using a high-speed centrifuge, perform centrifugation for 20 minutes under a centrifugal force of 8,000 x a. By this operation, undispersed solid matter was removed, and an extremely stable magnetite colloid dispersion liquid 1830P was obtained using toluene as a dispersion medium. This dispersion was concentrated under reduced pressure while being heated to a concentration of 500 mg.
Finished concentrating at the time of Tonatsutomo.

この濃縮分散液は、更に８０００Ｘ（）の遠ルカ下で３
０分間遠心分離を行つ九が、はとんど沈殿物を生じない
安定な母性流体であつ几。この磁性流体は、得量４９５
？、鉄含有量２５．５チで、磁化の強さ３８０　Ｇａｕ
ｓｓ　（＠場５００００ｅ）全有していた。This concentrated dispersion was further heated at 8000X () for 3
Centrifuging for 0 minutes is a stable mother fluid that rarely produces precipitates. This magnetic fluid has a yield of 495
? , the iron content is 25.5 cm, and the magnetization strength is 380 Gau.
ss (@Ba50000e) had all of them.

実施例２ 第−鉄塩及び第二鉄塩の併用割合を第一鉄イオンと第二
鉄イオンのモル比で１：２となるように調製し、有機溶
媒に灯油、有機酸塩にオレイン酸す）　ＩＪウムを用い
良磁性流体の作製。Example 2 The combination ratio of ferrous salt and ferric salt was adjusted so that the molar ratio of ferrous ion to ferric ion was 1:2, and kerosene was used as the organic solvent and oleic acid was used as the organic acid salt. ) Preparation of good magnetic fluid using IJum.

５！の四日フラスコを用い、水４０？、灯油１０００？
、水酸化ナトリウム１４．０　ｆ　（０，３４９モル）
を順次加え、攪拌しながらオレイン酸９６ＰＣ０，３４
９モル）を添加し、液温を７５〜８０℃に保ちながら３
０分間攪拌するとオレイン酸ナトリウムを含むエマルジ
ョンとなつｔ６次に、液温を３５℃に下げ、１４．５　
％アンモニア水１０３４．３？　（８，８モル）を加え
て攪拌混合し、均一ナエマルジョンヲ得九。5! Using a four-day flask, add 40 ml of water. , Kerosene 1000?
, sodium hydroxide 14.0 f (0,349 mol)
Sequentially add oleic acid 96PC0.34 while stirring.
9 mol) was added, and while keeping the liquid temperature at 75-80℃,
After stirring for 0 minutes, an emulsion containing sodium oleate is formed.Next, the liquid temperature is lowered to 35°C, and 14.5
%Ammonia water 1034.3? (8.8 mol) was added and stirred to obtain a homogeneous emulsion.

別にあらかじめ硫酸第１鉄７水塩２７８ｙ（１モＡ／）
、硫酸第２鉄６水塩５０８ｆ（１モル）、水１１２５ｒ
の混合水溶液金調裂しておき、この鉄塩水鹸液を前記の
エマルション中に滴下し、マグネタイトコロイドの生成
及び吸着処理全行つ几。鉄塩水浴液の滴下は２．５時間
を要し、液温は滴下直前の３０℃から終了時３９℃に上
昇し几。滴下終了時点で反応液は、黒色の分散液となつ
几ｔめ、液温を７５〜８０℃に上げ％３０分間攪拌・熟
成し友。この後、液温全３０℃に下げ、高速遠心機音用
い、３０００ＸＧの遠心力下で５分間遠心分離を行った
。この油水分離に工つ、灯油中にマグネタイトコロイド
が分散し＊Ｗが得られた。Separately, ferrous sulfate heptahydrate 278y (1 moA/)
, ferric sulfate hexahydrate 508f (1 mol), water 1125r
A mixed aqueous solution of the above-mentioned iron salt solution is added dropwise to the above-mentioned emulsion to complete the production and adsorption treatment of magnetite colloid. Dropping of the iron salt bath solution took 2.5 hours, and the temperature of the liquid rose from 30°C just before dropping to 39°C at the end. At the end of the dropwise addition, the reaction solution turned into a black dispersion, and the temperature was raised to 75-80°C and stirred and aged for 30 minutes. Thereafter, the liquid temperature was lowered to 30° C., and centrifugation was performed for 5 minutes under a centrifugal force of 3000×G using high-speed centrifuge sound. In this oil-water separation, magnetite colloid was dispersed in kerosene to obtain *W.

この分散液は、実施例１と同様に灯油との共沸脱水によ
り、わずかに残存する水を系外に除去し几後、８０００
８Ｇの遠心力下で２０分間遠心分離を行つ友。この操作
により非分散固形物は取り除かれ、灯油を分散媒としｔ
極めて安定なマグネタイトコロイド分散液１２２０ｆが
得られた。この分散液は加熱されながら減圧濃縮され、
濃縮液が５　（ｌ　Ｏｆとなった時点で濃縮を終了した
。This dispersion liquid was subjected to azeotropic dehydration with kerosene in the same manner as in Example 1 to remove a small amount of remaining water from the system, and after cooling, it was heated to 8000
Centrifuge for 20 minutes under 8G centrifugal force. This operation removes non-dispersed solids and uses kerosene as a dispersion medium.
An extremely stable magnetite colloid dispersion 1220f was obtained. This dispersion is concentrated under reduced pressure while being heated.
Concentration was terminated when the concentration reached 5 (l Of).

この濃縮分散液は、実施例１と同様に８０００ＸＧの遠
心力下で３０分間遠心分離を行ったが、はとんど沈殿物
を生じない極めて安定な磁性流体でめった。この磁性流
体は、得１４９５ｆ。This concentrated dispersion was centrifuged for 30 minutes under a centrifugal force of 8,000×G in the same manner as in Example 1, but was diluted with an extremely stable magnetic fluid that hardly produced any precipitates. This magnetic fluid has a yield of 1495f.

鉄含有量２５．４　％で、磁化の強さ３８０　Ｇａｕｓ
ｓ（磁場５００００ｅ）を有していた。Iron content 25.4%, magnetization strength 380 Gauss
s (magnetic field 50,000e).

実施例３ 実施例１において、２種の鉄塩の併用割合が鉄イオンの
モル比で１：１となるようにモル比を変えた。すなわち
、硫酸第１鉄７水塩４２４．５ｒ（１，５２８モル）、
硫酸第２鉄６水塩３８７．８ｒ（０，７６４モル）、対
応する２８チアンモニア水５１０．２ｆ（８，４０４モ
ル）を用いて実施例１と同様の方法で作製し、４９０９
の磁性流体を得た。Example 3 In Example 1, the molar ratio of the two types of iron salts was changed so that the molar ratio of iron ions was 1:1. That is, ferrous sulfate heptahydrate 424.5r (1,528 mol),
Produced in the same manner as in Example 1 using 387.8r (0,764 mol) of ferric sulfate hexahydrate and 510.2f (8,404 mol) of the corresponding 28 thiammonium aqueous solution, 4909
ferrofluid was obtained.

この磁性流体は、実施例１と同様の磁化能力及び分散安
定性を有しており、鉄含有量２５．０　％、磁化の強さ
３７０　Ｇａｕｓｓ　（磁場５００００ｅ）であつ友。This magnetic fluid has the same magnetization ability and dispersion stability as Example 1, has an iron content of 25.0%, and a magnetization strength of 370 Gauss (magnetic field of 50,000 e).

実施例４ 実施例１において、２廊の鉄塩全混合せずに、順次添加
する方法を試みた。すなわち、硫酸第２鉄６水塩５０８
　ｔ、水５７０ｔの混合水浴液を添加し１次に硫酸第１
鉄７水塩２７８ｆ、水５５５ｆの混合水溶ｆｉ’に添加
し友。この分割添加以外は、実施例１と同様の方法で作
製し、４９２ｇの磁性流体を得友。この磁性流体は、実
施例１と同様の磁化能力及び分散安定性を有しており、
鉄含有量２５．２９６　、磁化の強さ３７０Ｇａｕｓｓ
　（磁場５００００ｅ）であった。Example 4 In Example 1, a method was tried in which the two iron salts were added sequentially without being completely mixed. That is, ferric sulfate hexahydrate 508
t, a mixed water bath solution of 570 t of water was added, and then sulfuric acid
It is added to a mixed aqueous solution of 278f of iron heptahydrate salt and 555f of water. The magnetic fluid was prepared in the same manner as in Example 1 except for this divided addition, and 492 g of magnetic fluid was obtained. This magnetic fluid has the same magnetization ability and dispersion stability as in Example 1,
Iron content 25.296, magnetization strength 370 Gauss
(magnetic field 50,000e).

実施例５ 実施例１において、アンモニア水の代わりに水酸化ナト
リウムを、鉄の無機酸塩として硝酸塩音用いて行った。Example 5 In Example 1, sodium hydroxide was used instead of aqueous ammonia, and nitrate salt was used as the inorganic acid salt of iron.

すなわち、あらかじめオレイン酸ナトリウム生成及びマ
グネタイト生成に各々必要な水酸化す）　ＩＪウムの合
計量３５０．７ｆ（８，７６８モル）を、水４００を及
びトルエン１６００ｆに共存させておく。また鉄塩水溶
液としては、硝酸第１鉄６水塩２８７．９ｆ（１モル）
、硝酸第２鉄６水塩６９９．８ｔ（２モル）、水１２０
０２の混合水浴液を用いた。前記のアルカリ及び無機酸
塩以外は、実施例１と同様の方法で作製し、４４５ｔの
磁性流体を得た。この磁性流体は、実施例１と同様の磁
化力及び分散安定性を有しており、鉄含有量２８．２％
、磁化の強さ３７０　Ｇａｕｓｓ　（磁場５００００ｅ
）であった。That is, a total amount of 350.7 f (8,768 mol) of IJium hydroxide, which is necessary for the production of sodium oleate and the production of magnetite, is made to coexist in advance with 400 f of water and 1600 f of toluene. In addition, as an iron salt aqueous solution, ferrous nitrate hexahydrate 287.9f (1 mol)
, ferric nitrate hexahydrate 699.8t (2 mol), water 120
A mixed water bath solution of No. 02 was used. Except for the alkali and inorganic acid salt mentioned above, it was produced in the same manner as in Example 1 to obtain 445 t of magnetic fluid. This magnetic fluid has the same magnetizing force and dispersion stability as Example 1, and has an iron content of 28.2%.
, magnetization strength 370 Gauss (magnetic field 50000e
)Met.

実施例６ 実施例１と同様に作製された遠心分離処理済みのトルエ
ン希釈マグネタイトコロイド分散液について、各種の高
沸点有機溶媒への置換全滅み友、すなわち、前記の分散
液１８３（ｌに、高沸点有機溶媒２８０〜３００１を加
え、加熱しながら減圧濃縮を行い、トルエンを完全に留
去することにより高沸点有機溶媒で置換された分散液が
得られた。Example 6 A centrifuged toluene-diluted magnetite colloid dispersion prepared in the same manner as in Example 1 was replaced with various high-boiling point organic solvents. A boiling point organic solvent of 280 to 3001 was added and concentrated under reduced pressure while heating, and toluene was completely distilled off to obtain a dispersion liquid substituted with a high boiling point organic solvent.

この高沸点有機溶媒置換分散液は、更に８０００×Ｇの
遠心力下で３０分間遠心分離を行ったが、はとんど沈殿
物を生じない極めて安定な磁性流体であった。This high-boiling organic solvent-substituted dispersion was further centrifuged for 30 minutes under a centrifugal force of 8,000×G, but was found to be an extremely stable magnetic fluid that hardly produced any precipitates.

各種高沸点有機溶媒で置換した結果を表−１実施例７ 第一鉄イオンと第二鉄イオンとのモル比で１：２となる
ように調製し、有＠溶媒にトルエンを用い、有機酸塩（
分散剤）全各々代えた時の磁性流体の作製。Table 1 shows the results of substitution with various high-boiling organic solvents. salt(
Dispersant) Preparation of magnetic fluid when changing each one.

７−１）　　分散剤にオレイン酸アンモニウムに用いｔ
時。7-1) Used for ammonium oleate as a dispersant
Time.

５！の四ロフラスコを用い、水４０ｒ、）ルエン１６０
（１，２８慢アンモニア水５５５．５？（オレイン酸ア
ンモニウム生成及びマグネタイト生成に必要な合計量、
９．１４９モル）を順次加え、攪拌しながらオレイン＠
９６　ｒ　（０，３４９モル）を添加し友。次いで４０
℃で３０分間熟成し、オレイン酸アンモニウム及び水酸
化アンモニウムを含む均一なエマルションを得た。5! Using a four-hole flask, 40 r of water, 160 r of toluene
(1,28 Chronic ammonia water 555.5? (Total amount required for ammonium oleate production and magnetite production,
9.149 mol) were added one after another, and while stirring, olein@
96 r (0,349 mol) was added. then 40
A uniform emulsion containing ammonium oleate and ammonium hydroxide was obtained by aging at ℃ for 30 minutes.

この後の操作は、実施例１と同様に行い、４９４？の磁
性流体を得友。この磁性流体を工、実施例１と同様の磁
化能力及び分散安定性含有しており、鉄含有量２５．５
％、磁化の強さ３８０ＧａｕＳ５　（磁場５００００ｅ
）でおり友。The subsequent operations were performed in the same manner as in Example 1, and 494? Friendly magnetic fluid. This magnetic fluid has the same magnetization ability and dispersion stability as Example 1, and has an iron content of 25.5
%, magnetization strength 380 GauS5 (magnetic field 50000e
) deori tomo.

７−２）　　分散剤にナフテン酸ナトリウムを用いた時
。7-2) When sodium naphthenate is used as a dispersant.

５！の四ロフラスコを用い、水４０ｆ、）ルエン１６０
（１、水酸化ナトリウム１２．８Ｐ（０，３２モル）全
順次加え、攪拌しながらナフテン酸１１２．２５’　（
０，３２モル）を添加し、液温７５〜８０℃に保ちなが
ら３０分間攪拌するとナフテン酸ナトリウムを含むエマ
ルジョンとなつ几。次に、液温を３５℃に下げ、２８チ
アンモニア水５３４．３９　（８，８モル）を加えて攪
拌混合し、均一なエマルションヲ得た。5! Using a four-hole flask, 40 f water,) 160 ml of toluene
(1. Sodium hydroxide 12.8P (0.32 mol) was added in sequence, and while stirring, naphthenic acid 112.25' (
0.32 mol) and stirred for 30 minutes while keeping the liquid temperature at 75-80°C, an emulsion containing sodium naphthenate was formed. Next, the liquid temperature was lowered to 35°C, and 534.39 (8.8 mol) of 28 thiammonium water was added and mixed with stirring to obtain a uniform emulsion.

この後の操作は、実施例１と同様に行い、４９６？の磁
性流体金得比ゆこの磁性流体は、実施例１と同様の磁化
能力及び分散安定性を有しており、鉄含有量２５．３％
、磁化の強さ３８０Ｇａｕｓｓ　（磁場５ｏ０００ｅ）
であった。The subsequent operations were performed in the same manner as in Example 1, and 496? This magnetic fluid has the same magnetization ability and dispersion stability as Example 1, and has an iron content of 25.3%.
, magnetization strength 380 Gauss (magnetic field 5o000e)
Met.

７−３）　　分散剤にす７テン酸鉄を用いた時。7-3) When using iron 7thenate as a dispersant.

実施例７−２）と同様にしてナフテン酸ナトリウムを生
成させ、硫酸第１鉄７水塩４４．５　Ｐ（０，１−モル
）との塩交換反応によりナフテン酸鉄とし友後、液温３
５℃で２８％アンモニア水５３４．３？（８，８モル）
を加えて攪拌混合し、均一なエマルションを得ｔ０ この後の操作は、実施例１と同様に行い、４９６ｔの磁
性流体と得九。この磁性流体は、実施例１と同様の磁化
能力及び分散安定性含有しており、鉄含有量２６．５　
％、ａ化の強さ３８０Ｇａｕｓｓ　（磁場５００００ｅ
）であつ友。Sodium naphthenate was produced in the same manner as in Example 7-2), and made into iron naphthenate by a salt exchange reaction with 44.5 P (0.1-mol) of ferrous sulfate heptahydrate. 3
28% ammonia water at 5℃ 534.3? (8.8 moles)
was added and stirred to obtain a uniform emulsion.The subsequent operations were carried out in the same manner as in Example 1, and 496 tons of magnetic fluid was added. This magnetic fluid has the same magnetizing ability and dispersion stability as Example 1, and has an iron content of 26.5
%, strength of a 380 Gauss (magnetic field 50000e
) De Atsutomo.

７−４）　　分散剤にシアルギルベンゼンスルホン酸マ
グネシウム（平均分子量９２０、純度５０チ、松材石油
■社裂、モレスコアンパ−８Ｍ−５ＯＮ）を用いた時。7-4) When magnesium sialylbenzene sulfonate (average molecular weight 920, purity 50%, Matsuzai Sekiyu ■Shari, Moresco Amper 8M-5ON) was used as a dispersant.

５ｊの四ロフラスコを用い、トルエン１６００ｔ、モレ
スコアンパ−８Ｍ−５ＯＮ　２５６　？、２８チアンモ
ニア水５３４．：ｌ（８，８モル）を順次加えて攪拌混
合し、均一なエマル・ゾヨ／を得た。Using a 5J four-hole flask, 1600 tons of toluene, Moresco Amper 8M-5ON 256? , 28 thiammonia water 534. :1 (8.8 mol) was sequentially added and mixed with stirring to obtain a homogeneous Emul Zoyo/.

この後の操作は、実施例１と同様に行い、４９０ｔの磁
性流体を得友。この磁性流体は、実施例１と同様の磁化
能力及び分散安定性含有しており、鉄含有ｆＬ２４．９
％、磁化の強さ３６５Ｇａｕｓｓ　（磁場５００００ｅ
）であった。The subsequent operations were performed in the same manner as in Example 1, and 490 t of magnetic fluid was obtained. This magnetic fluid has the same magnetization ability and dispersion stability as in Example 1, and contains iron fL24.9.
%, magnetization strength 365 Gauss (magnetic field 50000e
)Met.

Claims (1)

【特許請求の範囲】 １、有機溶媒の存在下、次の４要素の全てを適宜選択さ
れた順で混合し反応させることを特徴とする磁性流体の
製造方法。 （１）水酸化アルカリ及び／又は水酸化アンモニウム （２）有機酸及び／又はその塩 （３）第一鉄塩 （４）第二鉄塩 ２、水酸化アルカリ又は水酸化アンモニウムと有機酸及
び／又はその塩との混合物に第一鉄塩と第２鉄塩とを同
時に又は任意の順で加えることを特徴とする特許請求の
範囲第１項記載の方法。[Claims] 1. A method for producing a magnetic fluid, which comprises mixing and reacting all of the following four elements in an appropriately selected order in the presence of an organic solvent. (1) Alkali hydroxide and/or ammonium hydroxide (2) Organic acid and/or its salt (3) Ferrous salt (4) Ferric salt 2, alkali hydroxide or ammonium hydroxide and organic acid and/or The method according to claim 1, characterized in that the ferrous salt and the ferric salt are added simultaneously or in any order to the mixture with the ferrous salt or the salt thereof.