JPH04170325A - Production of granular magnetite - Google Patents
Production of granular magnetiteInfo
- Publication number
- JPH04170325A JPH04170325A JP29683390A JP29683390A JPH04170325A JP H04170325 A JPH04170325 A JP H04170325A JP 29683390 A JP29683390 A JP 29683390A JP 29683390 A JP29683390 A JP 29683390A JP H04170325 A JPH04170325 A JP H04170325A
- Authority
- JP
- Japan
- Prior art keywords
- granular
- particles
- maghemite
- hematite
- granular magnetite
- 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
Links
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 title claims abstract description 75
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 229910052595 hematite Inorganic materials 0.000 claims abstract description 47
- 239000011019 hematite Substances 0.000 claims abstract description 47
- 238000010438 heat treatment Methods 0.000 claims abstract description 17
- 230000001590 oxidative effect Effects 0.000 claims abstract description 12
- 239000002245 particle Substances 0.000 claims description 143
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 claims description 38
- 150000001875 compounds Chemical class 0.000 claims description 35
- 239000011246 composite particle Substances 0.000 claims description 30
- 239000000843 powder Substances 0.000 claims description 28
- 239000007864 aqueous solution Substances 0.000 claims description 26
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 26
- 229910052782 aluminium Inorganic materials 0.000 claims description 23
- 229910052710 silicon Inorganic materials 0.000 claims description 23
- 238000007254 oxidation reaction Methods 0.000 claims description 10
- 230000003647 oxidation Effects 0.000 claims description 9
- 230000005415 magnetization Effects 0.000 abstract description 30
- 238000000034 method Methods 0.000 abstract description 16
- 239000011248 coating agent Substances 0.000 abstract description 5
- 238000000576 coating method Methods 0.000 abstract description 5
- 239000002131 composite material Substances 0.000 abstract 2
- 230000005291 magnetic effect Effects 0.000 description 22
- 239000000463 material Substances 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 238000006722 reduction reaction Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 239000007858 starting material Substances 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 235000019353 potassium silicate Nutrition 0.000 description 4
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 229910052737 gold Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 2
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- BYFGZMCJNACEKR-UHFFFAOYSA-N aluminium(i) oxide Chemical compound [Al]O[Al] BYFGZMCJNACEKR-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000000975 co-precipitation Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000001493 electron microscopy Methods 0.000 description 2
- 239000011790 ferrous sulphate Substances 0.000 description 2
- 235000003891 ferrous sulphate Nutrition 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 2
- 239000003973 paint Substances 0.000 description 2
- 239000000049 pigment Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- 239000004111 Potassium silicate Substances 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 239000001034 iron oxide pigment Substances 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
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 239000006247 magnetic powder Substances 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- NNHHDJVEYQHLHG-UHFFFAOYSA-N potassium silicate Chemical compound [K+].[K+].[O-][Si]([O-])=O NNHHDJVEYQHLHG-UHFFFAOYSA-N 0.000 description 1
- 229910052913 potassium silicate Inorganic materials 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910001388 sodium aluminate Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 235000019794 sodium silicate Nutrition 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Compounds Of Iron (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、高い保磁力と大きな残留磁化とを有し、しか
も、これら両特性を所望の値に制御することが出来る粒
状マグネタイト粒子粉末の製造法に関するものである。Detailed Description of the Invention [Field of Industrial Application] The present invention provides a granular magnetite particle powder that has a high coercive force and a large residual magnetization, and can control both of these properties to desired values. It concerns the manufacturing method.
本発明に係る粒状マグネタイト粒子粉末の主な用途は、
磁性トナー用、磁気記録媒体用、磁性インク文字認識Ｍ
ａｇｎｅｔｉｃ Ｉｎｋ Ｃｈａｒａｃｔｅｒ Ｒｅｃ
ｏｒｇｎｉｔｉｏｎ （以下、旧ＣＲという。）用材料
粒子粉末である。The main uses of the granular magnetite particle powder according to the present invention are:
For magnetic toner, for magnetic recording media, for magnetic ink character recognition M
agnetic ink character rec
This is a material particle powder for organization (hereinafter referred to as former CR).
粒状マグネタイト粒子粉末は、黒色で優れた分散性を有
する強磁性粒子であることから、樹脂中に混合分散させ
て５〜２５μ−の複合体粒子とすることにより静ｉｔ？
ｊ［写の為の磁性トナー用材料粒子粉末として使用され
ている。Since the granular magnetite particles are black and ferromagnetic particles with excellent dispersibility, they can be mixed and dispersed in a resin to form composite particles of 5 to 25 μ-.
j [Used as a material particle powder for magnetic toner for copying.
また、粒状マグネタイト粒子粉末は、磁気的に等方性で
ある粒子形態を備えていることから、ビヒクル中に混合
分散させて磁性塗料とし、該磁性塗料をソノシート状の
ポリエステルヘースの片面或いは両面に塗布して、磁気
記録媒体、特にフロッピーディスク用材料粒子粉末とし
て使用されている。In addition, since the granular magnetite particle powder has a magnetically isotropic particle form, it can be mixed and dispersed in a vehicle to make a magnetic paint, and the magnetic paint can be coated on one or both sides of a sonosheet-like polyester haze. It is used as material particles for magnetic recording media, especially floppy disks.
更に、近時、小切手等に通常の文字による記載事項と同
時に暗号化した情報を高速レーザープリンタを用いて印
刷することが試みられているが、この印刷システムにお
いて粒状マグネタイト粒子を樹脂中に分散混合させて得
られる複合体粒子を印刷用磁性トナーとして用いる等−
ＩＣＲ用材用材子粒子粉末ての使用が期待されている。Furthermore, in recent years, attempts have been made to use high-speed laser printers to print encrypted information on checks, etc. at the same time as information written in regular letters, but in this printing system, granular magnetite particles are dispersed and mixed in resin. The resulting composite particles are used as magnetic toner for printing, etc.
It is expected to be used as material particle powder for ICR materials.
上記いずれの分野においても高性能化、高品質化の為の
要求はとどまるところがなく、材料粒子粉末である粒状
マグネタイト粒子粉末についても保磁力及び残留磁化の
向上が重要視されているが、周辺機器や他材料、他特性
との兼ね合いからの制約が伴い、高い保磁力と大きな残
留磁化を有するとともに、用途目的に応してこれらを適
当な値に制御できることが強く要求されている。In all of the above fields, there is an unstoppable demand for higher performance and higher quality, and it is important to improve the coercive force and residual magnetization of granular magnetite particles, which are material particles, but peripheral equipment There is a strong demand for high coercive force and large residual magnetization, as well as the ability to control these to appropriate values depending on the purpose of use.
この事実は、磁性トナー用材料粒子粉末としての粒状マ
グネタイト粒子粉末に関して言えば、特開昭６１−６３
５３２号公報の「組成ＰｅＯｘ （ここで１．３３≦Ｘ
≦１．５）の磁性酸化鉄顔料は静電写真複写方法のため
・・・・・・の磁性トナーの製造に対して使用される。This fact is true in JP-A-61-63 regarding granular magnetite particles as material particles for magnetic toner.
No. 532, “Composition PeOx (where 1.33≦X
Magnetic iron oxide pigments of ≦1.5) are used for the production of magnetic toners for electrostatographic reproduction processes.
約８０−１３００ｅの保磁力（Ｃｏｅｒｃｒｖｅ Ｆｌ
ｅＩｄ Ｓｉｒｅｎｇｔｈｓ） （＋Ｈｃ）を有する等
動磁性顔料が、その目的に対する通常の方法において広
く用いられている。しかしながら、最近の１成分トナー
においては、これらの顔料に対してさらに大きな要求が
なされている。それ故、その保磁力は１８０〜２５００
ｅ又はそれ以上の範囲内でなければならない。」なる記
載の通りである。Coercive force of about 80-1300e (Coercrve Fl
Isodynamic pigments with eId Sirengths) (+Hc) are widely used in conventional methods for that purpose. However, in modern one-component toners, even greater demands are placed on these pigments. Therefore, its coercive force is 180-2500
Must be within the range of e or above. ” as stated.
また、磁気記録媒体、特にフロッピーディスク用材料粒
子粉末としての粒状マグネタイト粒子粉末に関して言え
ば、特公昭６１−３１０５７号公報の［高記録密度特性
、高出力特性及び再生出力の安定性が要求されている。In addition, regarding granular magnetite particles as material particles for magnetic recording media, especially floppy disks, Japanese Patent Publication No. 61-31057 [Requires high recording density characteristics, high output characteristics, and stability of reproduction output] There is.
フロッピーディスクに対する上記の要求を満足させるた
めに適した磁気記録用磁性粒子粉末の特性は、高い保磁
力Ｈｃ・・・・を有し・・・」、Ｆ本発明によれば、高
保磁力、殊に１３００ｅ以上を有する磁気的に等方性の
粒状マグネタイト粒子粉末を得ることができるので、現
在最も要求されている・・・・磁気記録媒体、特にフロ
ッピーディスク用磁性粉末として使用することができる
。The characteristics of the magnetic particles for magnetic recording suitable for satisfying the above requirements for floppy disks include a high coercive force Hc...''FAccording to the present invention, a high coercive force, Since it is possible to obtain a magnetically isotropic granular magnetite particle powder having an angle of 1300e or more, it can be used as magnetic powder for magnetic recording media, especially floppy disks, which is currently most demanded.
」なる記載の通りである。” as stated.
更に、Ｍ［ＣＲ用材料粒子粉末としての粒状マグネタイ
ト粒子粉末は、出力特性を考慮すれば、残留−磁化が１
２〜２０ｅｍｕ／ｇ 、好ましくは１４〜１８ｅｍｕ／
ｇ程度であることが要求されている。Furthermore, considering the output characteristics, the granular magnetite particles used as M[CR material particles have a residual magnetization of 1.
2-20 emu/g, preferably 14-18 emu/
It is required that it be about g.
従来、粒状マグネタイト粒子粉末の製造法としては、ｐ
ｅ ＠ ＋を含む水溶液中から合成する、所謂湿式法
が知られている。Conventionally, as a method for producing granular magnetite particle powder, p
A so-called wet method is known in which synthesis is performed from an aqueous solution containing e@+.
即ち、粒状マグぶタイト粒子は、硫酸第一鉄等の第一鉄
塩水溶液と水酸化ナトリウム、炭酸ナトリウム等のアル
カリ性水溶液とを混合して得られたＦｅ（Ｏ）Ｉ）ｚ又
はＦｅＣ０１等のＦｅ含有沈澱物を含む水溶液に６０−
１００″Ｃの温度範囲において酸化性ガスを通気して黒
色沈澱物を生成させ、次いで、酸相等を水洗除去した後
、変色させない様に乾燥することにより製造される。That is, granular magbutite particles are made of Fe(O)I)z or FeC01, etc., obtained by mixing a ferrous salt aqueous solution such as ferrous sulfate with an alkaline aqueous solution such as sodium hydroxide or sodium carbonate. 60- to an aqueous solution containing a Fe-containing precipitate.
It is produced by passing an oxidizing gas in a temperature range of 100''C to form a black precipitate, then washing away the acid phase and the like with water, and then drying to prevent discoloration.
また、高い保磁力と大きな残留磁化を有する粒状マグネ
タイト粒子を製造する為の方法として、上記湿式法によ
り得られた粒状マグネタイト粒子を出発物粒子とし、該
出発物粒子を酸化性雰囲気中で加熱酸化して粒状へマグ
イト粒子とし、次いで還元性雰囲気中で加熱還元する方
法が知られている（前出特公昭６１−３１０５７号公報
、特公平１−３６８６４号公報、前出特開昭６１−６３
５３２号公報）。In addition, as a method for producing granular magnetite particles having high coercive force and large residual magnetization, granular magnetite particles obtained by the above wet method are used as starting particles, and the starting particles are heated and oxidized in an oxidizing atmosphere. A method is known in which the particles are made into granular magite particles, and then heated and reduced in a reducing atmosphere (see Japanese Patent Publication No. 61-31057, Japanese Patent Publication No. 1-36864, Japanese Patent Application Laid-Open No. 61-63, cited above).
532).
高い保磁力と大きな残留磁化を有するとともに用途目的
に応じてこれら両特性を適当な値に制御することができ
る粒状マグネタイト粒子粉末は、現在量も要求されてい
るところであるが、前出湿式法により得られた粒状マグ
ネタイト粒子粉末は、保磁力が５０〜１２００’ｅ程度
と低く、また、残留磁化が高々１１〜１２ｅｒａｕ／ｇ
程度と小さいものであった。There is currently a demand for granular magnetite particles that have high coercive force and large residual magnetization, and can control both of these properties to appropriate values depending on the intended use. The obtained granular magnetite powder has a low coercive force of about 50 to 1200'e, and a residual magnetization of 11 to 12 erau/g at most.
It was a small amount.
また、前出特公昭６１−３１０５７号公報、特公平１−
３６８６４号公報及び前出特開昭６１〜６３５３２号公
報に記載の方法による場合には、１３００ｅ以上の高い
保磁力と１１〜１２ｅｍｕ／ｇ以上の大きな残留磁化を
有する粒状マグネタイト粒子粉末が得られるが、用途目
的に応じて所望の値に制御することは困難であった。In addition, the aforementioned Japanese Patent Publication No. 61-31057, Japanese Patent Publication No. 1-
In the case of the methods described in JP-A No. 36864 and JP-A-61-63532 mentioned above, granular magnetite particles having a high coercive force of 1300e or more and a large residual magnetization of 11 to 12 emu/g or more can be obtained. However, it has been difficult to control it to a desired value depending on the purpose of use.
そこで、本発明は、高い保磁力と大きな残留磁化を有す
るとともに、用途目的に応じてこれら両特性が適当な値
に制御された粒状マグネタイト粒子粉末を得ることを技
術的課題とする。Therefore, the technical object of the present invention is to obtain granular magnetite particles having high coercive force and large residual magnetization, and in which both of these properties are controlled to appropriate values depending on the purpose of use.
前記技術的課題は、次の通りの本発明によって達成でき
る。The above technical problem can be achieved by the present invention as follows.
即ち、本発明は、Ｆｅ２＋を含む水溶液中から合成され
たＡｌ又はＳｉ若しくはＡｌ及びＳｉを含有する粒状マ
グネタイト粒子、Ｐｅ２＋を含む水溶液中から合成され
た粒状マグネタイト粒子の粒子表面がＡｌ化合物又はＳ
１化合物若しくは当該両化合物によって被覆されている
粒子並びにＦｅ２＋を含む水溶液中から合成されたＡｌ
又はＳｉ若しくはＡｔ及びＳｉを含有する粒状マグネタ
イト粒子の粒子表面が前記化合物によって被覆されてい
る粒子のいずれかの粒子を酸化性雰囲気中３５０ ℃以
上７００″Ｃ未満の温度範囲で加熱酸化するか、又は必
要により、当該加熱酸化に先立ってあらかじめ２００℃
以上３５０ ”Ｃ未満の温度範囲で加熱酸化した後３５
０℃以上７００℃未満の温度範囲で加熱酸化して前記Ａ
ｌ又はＳｉ若しくはＡｌ及びＳｉを含有する粒状マグヘ
マイト・ヘマタイト複合粒子、酸化された前記化合物が
粒子表面に被覆されている粒状マグヘマイト・ヘマタイ
ト複合粒子又は酸化された前記化合物が粒子表面に被覆
されている前記Ａｌ又はＳｉ若しくはＡｌ及びＳｉを含
有する粒状マグヘマイト・ヘマタイト複合粒子とし、次
いで該粒状マグヘマイト・ヘマタイト複合粒子を還元性
雰囲気中２５０〜５００″Ｃの温度範囲で加熱還元する
ことからなる粒状マグネタイト粒子粉末の製造法である
。That is, the present invention provides granular magnetite particles containing Al or Si or Al and Si synthesized from an aqueous solution containing Fe2+, and granular magnetite particles synthesized from an aqueous solution containing Pe2+ whose particle surface is an Al compound or S
Al synthesized from particles coated with one compound or both compounds and an aqueous solution containing Fe2+
or by heating and oxidizing any of the granular magnetite particles containing Si or At and Si whose particle surfaces are coated with the compound at a temperature range of 350° C. or higher and lower than 700″C in an oxidizing atmosphere; Or, if necessary, heat at 200℃ prior to the heating oxidation.
After heating and oxidizing in a temperature range of 350"C or more, 35"
The above-mentioned A
Granular maghemite-hematite composite particles containing L or Si or Al and Si, granular maghemite-hematite composite particles whose particle surfaces are coated with the oxidized compound, or whose particle surfaces are coated with the oxidized compound. Granular magnetite particles obtained by forming the granular maghemite-hematite composite particles containing Al or Si or Al and Si, and then reducing the granular maghemite-hematite composite particles by heating in a reducing atmosphere in a temperature range of 250 to 500''C. This is a method for producing powder.
次に、本発明実施にあたっての諸条件について述べる。Next, various conditions for implementing the present invention will be described.
本発明における粒状マグネタイト粒子は、湿式法により
得られた平均粒子径が０．１〜０．５μｍの六面体、八
面体、多面体、球状等各種形状を呈する粒状マグネタイ
ト粒子が用いられる。The granular magnetite particles used in the present invention are granular magnetite particles obtained by a wet method and exhibiting various shapes such as hexahedron, octahedron, polyhedron, and spherical shape with an average particle diameter of 0.1 to 0.5 μm.
尚、湿式法には、前述した方法の他に周知の所謂、共沈
法と言われる方法があり、この方法によって得られた粒
状マグネタイト粒子も同様に出発物粒子として用いるこ
とができる。In addition to the above-mentioned method, the wet method includes a well-known method called a coprecipitation method, and the granular magnetite particles obtained by this method can also be used as starting particles.
共沈方法は、硫酸第一鉄等の第一鉄塩水溶液と硫酸第二
鉄等の第二鉄塩水溶液を用い、Ｆｅ” ： Ｆｅ３゛が
１＝２となる混合鉄水溶液を調整し、該混合鉄水溶液中
にＮａＯＨ等のアルカリ性水溶液を１当量以上添加して
５０〜１００℃の温度範囲で加熱混合する方法である。The coprecipitation method uses a ferrous salt aqueous solution such as ferrous sulfate and a ferric salt aqueous solution such as ferric sulfate to prepare a mixed iron aqueous solution in which Fe":Fe3" is 1 = 2, and This is a method of adding 1 equivalent or more of an alkaline aqueous solution such as NaOH to a mixed iron aqueous solution and heating and mixing in a temperature range of 50 to 100°C.
本発明におけるＡｌ又はＳｉ若しくは＾！及びＳｉを含
有する粒状マグネタイト粒子は、前出湿式法において、
第一鉄塩水溶液、アルカリ性水溶液、酸化性ガスを通気
する前のＦｅ（ＯＨｈ又はＦｅＣ（ｈ等のＦｅ含有沈澱
物を含む水溶液、又は粒状マグネタイト粒子の生成反応
中のいずれかの水溶液中に、Ａｌ化合物又はＳｉ化合物
若しくは当該両化合物を添加することにより得られる。Al or Si or ^! in the present invention! In the wet method described above, the granular magnetite particles containing Si and
A ferrous salt aqueous solution, an alkaline aqueous solution, an aqueous solution containing Fe-containing precipitates such as Fe(OHh or FeC(h) before aerating an oxidizing gas, or an aqueous solution during the production reaction of granular magnetite particles. It can be obtained by adding an Al compound, a Si compound, or both.
添加量は、生成するマグネタイト粒子に対しＡｌ２（ｈ
又はＳｉＯ□換算で０．１〜５．０重量％である。The amount added is Al2 (h
Or, it is 0.1 to 5.0% by weight in terms of SiO□.
０．１重量％未満の場合には、粒子の変形と粒子相互間
の焼結が生じ好ましくない。If it is less than 0.1% by weight, deformation of particles and sintering between particles occur, which is not preferable.
５．０重量％を越える場合には、ヘマタイト化が生起し
にくく、粒状マグヘマイト・ヘマタイト複合粒子中のへ
マタイト量の制御が困難となり、本発明の目的とする保
磁力及び残留磁化が適当な値に制御された粒状マグネタ
イト粒子粉末を得ることが困難となる。また、還元反応
の進行が生起しにくくなる。If it exceeds 5.0% by weight, hematite formation is difficult to occur, making it difficult to control the amount of hematite in the granular maghemite/hematite composite particles, and the coercive force and residual magnetization targeted by the present invention cannot be maintained at appropriate values. It becomes difficult to obtain granular magnetite particle powder with controlled conditions. Further, the progress of the reduction reaction becomes difficult to occur.
Ａｌ化合物としては、硫酸アルミニウム、塩化アルミニ
ウム、硝酸アルミニウム、アルミン酸ナトリウム等が使
用できる。As the Al compound, aluminum sulfate, aluminum chloride, aluminum nitrate, sodium aluminate, etc. can be used.
Ｓｉ化合物としては、水ガラス、ケイ酸カリウム、ケイ
酸ナトリウム、コロイダルンリ力等が使用できる。As the Si compound, water glass, potassium silicate, sodium silicate, colloidal silicone, etc. can be used.
本発明における粒状マグネタイト粒子の被覆は、Ａｌ又
はＳｉ若しくはＡｌ及びＳｌを含有するか又は含有しな
い粒状マグネタイト粒子をＡｌ化合物又はＳ１化合物若
しくはＡｔ化合物及びＳ１化合物の水溶液に浸漬させる
方法、又は、Ａｌ又はＳ】若しくはＡｌ及びＳｉを含有
するか又は含有しない粒状マグ茅タイト粒子をＡｔ化合
物又はＳ１化合物若しくはＡｔ化合物及びＳ１化合物の
水溶液に浸漬させた後、酸性水溶液又はアルカリ性水溶
液を添加して、Ａｌの水酸化物、酸化水酸化物の形態又
はＳｌの酸化物、水酸化物の形態で前記粒状マグネタイ
ト粒子の粒子表面に沈着させる方法のいずれの方法でも
よいが、後者が好ましい。The coating of granular magnetite particles in the present invention can be carried out by immersing granular magnetite particles containing or not containing Al or Si or Al and Sl in an aqueous solution of an Al compound or an S1 compound or an At compound and an S1 compound; S] Or, after immersing granular magmatite particles containing or not containing Al and Si in an aqueous solution of an At compound or an S1 compound or an At compound and an S1 compound, an acidic aqueous solution or an alkaline aqueous solution is added to remove Al. It may be deposited on the surface of the granular magnetite particles in the form of hydroxide, hydroxide oxide, or oxide or hydroxide of Sl, but the latter is preferred.
本発明における被覆化合物の添加量は、出発物粒子であ
る粒状マグネタイト粒子に対しＡｌｚ（ｈ又はＳｉＯ□
換算で０．１〜２．０重量％である。The amount of the coating compound added in the present invention is determined based on the amount of Alz(h or SiO□
It is 0.1 to 2.0% by weight in terms of conversion.
０．１重量％未満の場合には、粒子の変形と粒子相互間
の焼結が生し好ましくない。If it is less than 0.1% by weight, deformation of the particles and sintering between particles occur, which is not preferable.
２．０重量％を越える場合には、ヘマタイト化が生起し
に＜＜、粒状マグヘマイト・ヘマタイト？Ｊ［金粒子中
のへマタイト量の制御が困難となり、本発明の目的とす
る保磁力及び残留磁化が適当な値に制御された粒状マグ
ネタイト粒子粉末を得ることが困難となる。また、還元
反応の進行が生起しにくくなる。If it exceeds 2.0% by weight, hematization may occur, resulting in granular maghemite/hematite? J [It becomes difficult to control the amount of hematite in the gold particles, and it becomes difficult to obtain granular magnetite particles whose coercive force and residual magnetization are controlled to appropriate values, which is the objective of the present invention. Further, the progress of the reduction reaction becomes difficult to occur.
Ａｔ化合物及びＳ１化合物としては、前出と同様のＡｌ
化合物及びＳｉ化合物が使用できる。As the At compound and the S1 compound, the same Al as mentioned above is used.
compounds and Si compounds can be used.
本発明における加熱酸化温度は、３５０°０以上７００
℃未満である。The heating oxidation temperature in the present invention is 350°0 or more and 700°
less than ℃.
３５０℃未満の場合には、粒状マグヘマイト・ヘマタイ
ト複合粒子中のへマタイト量の生成が不十分となり、保
磁力及び残留磁化が低い粒状マグネタイト粒子が得られ
る。If the temperature is lower than 350° C., the amount of hematite in the granular maghemite-hematite composite particles will be insufficient, and granular magnetite particles with low coercive force and low residual magnetization will be obtained.
７００℃以上の場合には、粒状マグヘマイト・ヘマタイ
トａ金粒子が得られず、粒状へマタイト粒子が生成する
為、得られる粒状マグネタイト粒子の保磁力及び残留磁
化の制御が困難となる。If the temperature is 700° C. or higher, granular maghemite/hematite a gold particles cannot be obtained, but granular hematite particles are generated, making it difficult to control the coercive force and residual magnetization of the obtained granular magnetite particles.
本発明においては、必要により３５０“Ｃ以上７００℃
未満の加熱酸化に先立ってあらかしめ２００℃以上３５
０ ”Ｃ未満の温度範囲で加熱酸化して粒状マグネタイ
ト粒子の発熱を充分生起させておくことにより粒状マグ
ヘマイト・ヘマタイト粒子への変態時における温度調整
が容易となり、粒状マグヘマイト へフタイト粒子中の
へマタイト量の制御が容易となる。In the present invention, if necessary, the
Preparation prior to heating oxidation at temperatures below 200°C or above 35°C
By heating and oxidizing the granular magnetite particles in a temperature range below 0"C to generate sufficient heat generation, temperature adjustment during transformation into granular maghemite/hematite particles becomes easy, and the hematite in the granular maghemite/heftite particles The amount can be easily controlled.
２００℃未満の場合には、粒状マグネタイト粒子の発熱
反応を生起させるのに長時間を要する。粒状マグネタイ
ト粒子の発熱はは３５０℃未満で十分であり、これ以上
の温度にする意味がない。If the temperature is less than 200°C, it takes a long time to cause the exothermic reaction of the granular magnetite particles. The heat generation of granular magnetite particles is sufficient at less than 350° C., and there is no point in increasing the temperature higher than this.
本発明における加熱還元温度は２５０〜５００ ℃であ
る。The heating reduction temperature in the present invention is 250 to 500°C.
２５０℃未満の場合には、還元反応の進行が遅く、粒状
マグネタイト粒子の生成に長時間を要する。If the temperature is lower than 250°C, the reduction reaction progresses slowly and it takes a long time to generate granular magnetite particles.
５００℃を越える場合には、還元反応が急激に進行して
粒子の変形と、粒子及び粒子相互間の焼結を引き起こし
てしまう。If the temperature exceeds 500°C, the reduction reaction will rapidly proceed, causing deformation of the particles and sintering of the particles and the particles themselves.
本発明において最も重要な点は、Ｆｅ２＋を含む水溶液
中から合成されたＡｌ又はＳｉ若しくはＡｌ及びＳｌを
含有する粒状マグネタイト粒子、Ｆｅ２゛を含む水溶液
中から合成された粒状マグネタイト粒子の粒子表面がＡ
ｔ化合物又はＳ１化合物若しくは当該側化合物によって
被覆されている粒子並びにＦｅ”°を含む水？８ｆｇ、
中から合成されたＡｌ又はＳｉ若しくはＡｌ及びＳｌを
含有する粒状マグネタイト粒子の粒子表面が前記化合物
によって被覆されている粒子のいずれかの粒子を酸化性
雲囲気中３５０℃以上７００℃未満の温度範囲で加熱酸
化して前記Ａｌ又はＳ１若しくはＡｌ及びＳｉを含有す
る粒状マグヘマイト・ヘマタイト複合粒子、酸化された
前記化合物が粒子表面に被覆されている粒状マグヘマイ
ト・ヘマタイト複合粒子又は酸化された前記化合物が粒
子表面に被覆されている前記Ａｌ又はＳｉ若しくはＡｌ
及びＳｉを含有する粒状マグヘマイト・ヘマタイト複合
粒子とし、次いで該粒状マグヘマイト・ヘマタイト複合
粒子を還元性雰囲気中２５０〜５００℃の温度範囲で加
熱還元した場合には、前記粒状マグヘマイト・ヘマタイ
トａ金粒子中のへマタイト量に対応した保磁力及び残留
磁化を有する粒状マグネタイト粒子が得られるという事
実である。The most important point in the present invention is that the particle surface of the granular magnetite particles containing Al or Si or Al and Sl synthesized from an aqueous solution containing Fe2+, and the granular magnetite particles synthesized from an aqueous solution containing Fe2
8 fg of water containing particles coated with the t compound or the S1 compound or the side compound as well as Fe"°,
Any of the granular magnetite particles containing Al or Si or Al and Sl synthesized from the inside, the particle surface of which is coated with the compound, is heated in an oxidizing cloud at a temperature range of 350°C or higher and lower than 700°C. Granular maghemite/hematite composite particles containing the Al or S1 or Al and Si by heating and oxidizing the particles, granular maghemite/hematite composite particles whose particle surfaces are coated with the oxidized compound, or particles containing the oxidized compound. The Al or Si or Al coated on the surface
When the granular maghemite/hematite composite particles are made into granular maghemite/hematite composite particles containing and Si, and then the granular maghemite/hematite composite particles are thermally reduced in a reducing atmosphere at a temperature range of 250 to 500°C, in the granular maghemite/hematite a gold particles. The fact is that granular magnetite particles having coercive force and residual magnetization corresponding to the amount of hematite can be obtained.
今、本発明者が行った数多くの実験例からその一部を抽
出して説明すれば、以下の通りである。Some of the numerous experimental examples conducted by the present inventor will be explained below.
図１及び図２は、それぞれ粒状マグヘマイト・ヘマタイ
ト複合粒子中のへマタイト量を種々変化させることによ
り得られた粒状マグネタイト粒子の保磁力及び残留磁化
と粒状マグヘマイト・ヘマタイト複合粒子中のへマタイ
ト量との関係を示したものである。Figures 1 and 2 show the coercive force and residual magnetization of granular magnetite particles obtained by varying the amount of hematite in granular maghemite/hematite composite particles, and the amount of hematite in granular maghemite/hematite composite particles, respectively. This shows the relationship between
尚、粒状マグヘマイト・ヘマタイト複合粒子中のヘマタ
イ）Ｉは、粒状マグヘマイト・ヘマタイト複合粒子の飽
和磁化の測定値を用いて表した。Incidentally, hematite (I) in the granular maghemite/hematite composite particles was expressed using the measured value of the saturation magnetization of the granular maghemite/hematite composite particles.
飽和磁化が小さくなる程、非磁性のへマタイト量が増加
していることを意味している。This means that as the saturation magnetization decreases, the amount of non-magnetic hematite increases.
図１及び図２中、線Ａ乃至Ｃはそれぞれ、４００〜６５
０℃の各種温度で加熱酸化した以外は後出実施例１、実
施例２及び実施例３と同様にして得られた各種粒状マグ
ネタイト粒子の保磁力値及び残留磁化値と粒状マグヘマ
イト・ヘマタイト複合粒子の飽和磁化値との関係を示し
たものである。In FIGS. 1 and 2, lines A to C are 400 to 65, respectively.
Coercive force values and residual magnetization values of various granular magnetite particles obtained in the same manner as in Example 1, Example 2, and Example 3 below, except that heating and oxidation were performed at various temperatures of 0° C., and granular maghemite/hematite composite particles This figure shows the relationship between the saturation magnetization value and the saturation magnetization value.
〔実施例］ 次に、実施例並びに比較例により、本発明を説明する。〔Example] Next, the present invention will be explained with reference to Examples and Comparative Examples.
尚、前出実施例、以下の実施例並びに比較例における粒
子の形状は電子顕微鏡によって観察したものである。The shapes of the particles in the preceding examples, the following examples, and comparative examples were observed using an electron microscope.
粒子粉末の磁気特性は、「振動試料型磁力計ＶＳＭ−３
Ｓ−１５Ｊ （東英工業■製）を用いて外部磁場１０
ＫＯｅの下で測定した値である。The magnetic properties of the powder particles were determined using the "Vibrating Sample Magnetometer VSM-3".
External magnetic field 10 using S-15J (manufactured by Toei Kogyo)
This is a value measured under KOe.
く出発物粒子の種類〉
Ｆｅ”°を含む水溶液を用いて酸化反応をする湿式法に
より製造した粒状マグ矛タイト粒子粉末の接待性を表１
に示した。Types of starting material particles〉 Table 1 shows the acceptability of granular maggotite particles produced by a wet method in which an oxidation reaction is carried out using an aqueous solution containing Fe.
It was shown to.
〈粒状マグネタイト粒子の製造〉
実施例１
粒状マグネタイト粒子粉末（Ｉｌ Ｉ Ｋｇを１０！の
水に添加混合して得られた懸濁液に水酸化す） ＩＪウ
ムを添加してｐＨ１ｌとした後、３号水ガラス（徳山曹
達■製、Ｓｉ量は５ｉ０２換算で２９重貴％に該当する
。<Manufacture of granular magnetite particles> Example 1 Granular magnetite particle powder (hydroxidation of a suspension obtained by adding and mixing 1 kg of Il I to 10! of water) After adding IJum to adjust the pH to 1 liter, No. 3 water glass (manufactured by Tokuyama Soda ■, the Si content corresponds to 29% preciousness in 5i02 terms).
Ｈ７，２ｇ （出発物粒子に対しＳｉＯ□換算で０．５
重量％に該当する。）を添加し、次いで攪拌、混合した
後、硫酸を添加してｐＨ９に調整し、前記粒状マグネタ
イト粒子の表面にＳｉＯ□被膜を析出させた黒色沈澱粒
子を得た。H7.2g (0.5 in terms of SiO□ based on the starting material particles)
Applies to weight%. ) was added, followed by stirring and mixing, and then sulfuric acid was added to adjust the pH to 9 to obtain black precipitated particles in which a SiO□ film was deposited on the surface of the granular magnetite particles.
上記黒色沈澱粒子を含む懸濁液を常法により濾過、水洗
、乾燥した。The suspension containing the black precipitated particles was filtered, washed with water, and dried by a conventional method.
得られた黒色粒子表面に存在しているＳｉＯ□量は、蛍
光Ｘ線分析の結果、ＳｉＯ□換冨で０．２５重量％であ
った。As a result of fluorescent X-ray analysis, the amount of SiO□ present on the surface of the obtained black particles was 0.25% by weight in terms of SiO□ conversion.
上記粒子表面がＳｉＯ□で被覆されている粒状マグネタ
イト粒子粉末ＩＫｇを３１の一端開放型レトルト容器中
に投入し、駆動回転させながら空気を毎分５１の割合で
通気し、５２０℃で９０分間加熱酸化して粒状マグヘマ
イト・ヘマタイト複合粒子粉末とした。The above granular magnetite particle powder IKg whose particle surface is coated with SiO□ was put into a retort container with one end open at 31, and air was aerated at a rate of 51 per minute while driving and rotating, and heated at 520°C for 90 minutes. It was oxidized to produce granular maghemite/hematite composite particle powder.
上記粒状マグヘマイト・ヘマタイト複合粒子粉末の一部
を取り出し、飽和磁化を測定した結果、７．４ ｅｍｕ
／ｇであった。A part of the above granular maghemite/hematite composite particle powder was taken out and the saturation magnetization was measured, and the result was 7.4 emu.
/g.
次に、レトルト内をＮオガスで置換した後、通気ガスを
毎分２２のＨ２ガスに切換え、３５０℃の温度で１８０
分間加熱還元して粒状マグ享タイト粒子粉末を得た。Next, after replacing the inside of the retort with N gas, the ventilation gas was switched to H2 gas at a rate of 22/min, and at a temperature of 350°C,
The mixture was heated and reduced for a minute to obtain granular magkyo-tite particle powder.
得られた粒状マグネタイト粒子粉末は、電子顕微鏡観察
の結果、平均径０，３５μｍであり、出発物粒子である
マグネタイト粒子の粒子形態を継承し、粒子−個一個バ
ラバラに独立したものであった。As a result of electron microscopy, the obtained granular magnetite particles had an average diameter of 0.35 μm, inherited the particle morphology of the starting magnetite particles, and were individually independent.
また、磁気測定の結果、保磁力Ｈｃは２２１０ｅ、残留
磁化σＳは１８．０ｅｌｌｕ／ｇであった。Further, as a result of magnetic measurement, the coercive force Hc was 2210e, and the residual magnetization σS was 18.0elu/g.
実施例２
粒状マグネタイト粒子粉末！Ｉｎ ｌ Ｋｇを１０２の
水に添加混合して得られた懸濁液に水酸化ナトリウムを
添加してｐＨ９とした後、３号水ガラス１７．２ｇ（出
発物粒子に対し５ｉ０２換算で０５重量％に該当する。Example 2 Granular magnetite particle powder! After adding sodium hydroxide to the suspension obtained by adding and mixing In l Kg to 102 of water to adjust the pH to 9, 17.2 g of No. 3 water glass (05% by weight based on the starting material particles in terms of 5i02) was added. Applies to.
）及び硫酸アルミニウム（米山薬品工業■製、Ａｌ量は
Ａｌ□Ｏ２換算で３０重量％に該当する。）１６．７ｇ
（出発物粒子に対しへ１□０．換夏で０．５重量％に該
当する。）を添加し、次いで、攪拌、混合した後、硫酸
を添加してｐＨ７に調整し、前舵粒状マグネタイト粒子
の表面に水酸化アルミニウムとＳｉＯ□を析出させた異
色沈澱粒子を得た。) and aluminum sulfate (manufactured by Yoneyama Pharmaceutical Industry ■, the amount of Al corresponds to 30% by weight in terms of Al□O2) 16.7 g
(corresponding to 1□0.0.5% by weight based on the starting material particles), stirred and mixed, and then added sulfuric acid to adjust the pH to 7. Different color precipitated particles were obtained in which aluminum hydroxide and SiO□ were precipitated on the surface of the particles.
上記黒色沈澱粒子を含む懸濁液を、常法により炉遇、水
洗、乾燥した。The suspension containing the black precipitated particles was heated in an oven, washed with water, and dried in a conventional manner.
得られた黒色粒子表面に存在しているＳｉ量及びＡｌ量
は、蛍光Ｘ線分析の結果、５ｉ０２換算でｏ、５４重量
％、Ａｌ．０３換算で０．３４重量％であった。As a result of fluorescent X-ray analysis, the amount of Si and Al present on the surface of the obtained black particles was determined to be o, 54% by weight in terms of 5i02, and Al. The amount was 0.34% by weight in terms of 0.03.
上記粒子表面が５ｉ０２及びＡｈＯｉで被覆されている
粒状マグネタイ粒子粉末ＩＫｇを３１の一端開放型レト
ルト容器中に投入し、駆動回転させながら空気を毎分５
Ｎの割合で通気し、５３０ ℃で６０分間加熱酸化して
粒状マグヘマイト・ヘマタイト複合粒子粉末とした。IKg of the granular magnetite particle powder whose particle surface is coated with 5i02 and AhOi was put into a 31 retort container with one end open, and air was pumped in at 5 minutes per minute while rotating the container.
It was aerated with a proportion of N, and heated and oxidized at 530° C. for 60 minutes to obtain granular maghemite/hematite composite particle powder.
上記粒状マグヘマイト・ヘマタイト複合粒子粉末の一部
を取り出し、飽和磁化を測定した結果、２８．３ｅｗｕ
／ｇであツタ・
次に、レトルト内をＮ２ガスで置換した後、通気ガスを
毎分５１のＮ２ガスに切換え、３５０℃の温度で１８０
分間加熱還元して粒状マグネタイト粒子粉末を得た。A part of the above granular maghemite/hematite composite particle powder was taken out and the saturation magnetization was measured, and the result was 28.3 ewu.
Next, after replacing the inside of the retort with N2 gas, the ventilation gas was switched to N2 gas at a rate of 51/min, and the temperature was 180℃ at a temperature of 350°C.
Granular magnetite particle powder was obtained by heating and reducing for a minute.
得られた粒状マグネタイト粒子粉末は、電子顕微鏡観察
の結果、平均径０，２８μ鎖であり、出発物粒子である
マグネタイト粒子の粒子形態を継承し、粒子−個一個ハ
ラハラに独立したものであった。As a result of electron microscopic observation, the obtained granular magnetite particles had an average diameter of 0.28μ chains, inherited the particle morphology of the starting material particles, magnetite particles, and each particle was completely independent. .
また、磁気測定の結果、保磁力Ｈｃは１７８０ｅ、残留
磁化σＳは１３．４ｅｍｕ／ｇであった。Further, as a result of magnetic measurement, the coercive force Hc was 1780e, and the residual magnetization σS was 13.4 emu/g.
実施例３ 実施例２と同様にして得られた粒子表面がＡｌ２Ｏ。Example 3 The particle surface obtained in the same manner as in Example 2 was Al2O.
で被覆されている粒状マグネタイト粒子粉末＠１Ｋｇを
３２の一端開放型レトルト容器中に投入し、駆動回転さ
せながら空気を毎分５Ｅの割合で通気し、５３０℃で９
０分間加熱酸化して粒状マグヘマイト・ヘマタイト複合
粒子粉末とした。1 kg of granular magnetite particles coated with 1 kg were placed in a 32 mm retort container with one end open, and air was aerated at a rate of 5 E/min while rotating, and heated at 530°C for 9 lbs.
The mixture was heated and oxidized for 0 minutes to obtain granular maghemite/hematite composite particle powder.
上記粒状マグヘマイト・ヘマタイト複合粒子粉末の一部
を取り出し、飽和磁化を測定した結果、２５、Ｏｅｍｕ
／ｇであった。As a result of taking out a part of the above granular maghemite/hematite composite particle powder and measuring the saturation magnetization, it was found that 25, Oemu
/g.
次に、レトルト内をＮ２ガスで置換した後、通気ガスを
毎分２！のＨｔガスに切換え、３５０″Ｃの温度で１２
０分間加熱還元して粒状マグ享タイト粒子粉末を得た。Next, after replacing the inside of the retort with N2 gas, the ventilation gas is turned on at 2 times per minute! Switch to Ht gas at 350″C for 12
The mixture was heated and reduced for 0 minutes to obtain granular magkyo-tite particle powder.
得られた粒状マグネタイト粒子粉末は、電子顕微鏡観察
の結果、平均径０，３０μｍであり、出発物粒子である
マグネタイト粒子の粒子形態を継承し、粒子−個一個ハ
ラハラに独立したものであった。As a result of electron microscopy, the obtained granular magnetite particles had an average diameter of 0.30 μm, inherited the particle morphology of the starting magnetite particles, and each particle was independent.
また、磁気測定の結果、保磁力Ｈｅは２１５０ｅ、残留
磁化σＳは１７．６ｅ＋ｓｕ／ｇであった。Further, as a result of magnetic measurement, the coercive force He was 2150e, and the residual magnetization σS was 17.6e+su/g.
実施例４〜１０、比較例１〜８
粒状マグネタイト粒子の種類、被覆物質の種類及び量、
加熱酸化処理の酸化温度及び酸化時間、前段加熱の有無
並びに粒状マグネタイト粒子の製造時における還元温度
及び還元時間を種々変化させた以外は、実施例１と同様
にして粒状マグネタイト粒子粉末を得た。Examples 4 to 10, Comparative Examples 1 to 8 Types of granular magnetite particles, type and amount of coating material,
Granular magnetite particle powder was obtained in the same manner as in Example 1, except that the oxidation temperature and oxidation time of the heating oxidation treatment, the presence or absence of pre-heating, and the reduction temperature and reduction time during the production of granular magnetite particles were varied.
この時の主要製造条件及び緒特性を表２に示す。Table 2 shows the main manufacturing conditions and characteristics at this time.
表１
〔発明の効果〕
本発明における粒状マグネタイト粒子粉末の製造法によ
れば、前出実施例に示した通り、高い保磁力と大きな残
留磁化を有し、粒状マグヘマイト・ヘマタイト複合粒子
中のへマタイト量に対応した所望の保磁力値及び残留磁
化値を有する粒状マグネタイト粒子を得ることができる
ので、磁気トナー用材料粒子粉末、磁気記録媒体用材料
粒子粉末及びＭＩＣＲ用材料粒材料粒子粉末好適である
。Table 1 [Effects of the Invention] According to the method for producing granular magnetite particles according to the present invention, as shown in the above-mentioned examples, the granular magnetite particles have a high coercive force and a large residual magnetization. Since it is possible to obtain granular magnetite particles having a desired coercive force value and residual magnetization value corresponding to the amount of matite, it is suitable for magnetic toner material particles, magnetic recording medium material particles, and MICR material particles. be.
図１及び図２は、それぞれ粒状マグヘマイト・ヘマタイ
ト複合粒子中のへマタイト量を種々変化させることによ
り得られた粒状マグネタイト粒子の保磁力及び残留磁化
と粒状マグヘマイト・ヘマタイト複合粒子中のへマタイ
ト量との関係を示したものである。Figures 1 and 2 show the coercive force and residual magnetization of granular magnetite particles obtained by varying the amount of hematite in granular maghemite/hematite composite particles, and the amount of hematite in granular maghemite/hematite composite particles, respectively. This shows the relationship between
Claims (2)
又はＳｉ若しくはＡｌ及びＳｉを含有する粒状マグネタ
イト粒子、Ｆｅ＾２＾＋を含む水溶液中から合成された
粒状マグネタイト粒子の粒子表面がＡｌ化合物又はＳｉ
化合物若しくは当該両化合物によって被覆されている粒
子並びにＦｅ＾２＾＋を含む水溶液中から合成されたＡ
ｌ又はＳｉ若しくはＡｌ及びＳｉを含有する粒状マグネ
タイト粒子の粒子表面が前記化合物によって被覆されて
いる粒子のいずれかの粒子を酸化性雰囲気中３５０℃以
上７００℃未満の温度範囲で加熱酸化して前記Ａｌ又は
Ｓｉ若しくはＡｌ及びＳｉを含有する粒状マグヘマイト
・ヘマタイト複合粒子、酸化された前記化合物が粒子表
面に被覆されている粒状マグヘマイト・ヘマタイト複合
粒子又は酸化された前記化合物が粒子表面に被覆されて
いるＡｌ又はＳｉ若しくはＡｌ及びＳｉを含有する粒状
マグヘマイト・ヘマタイト複合粒子とし、次いで該粒状
マグヘマイト・ヘマタイト複合粒子を還元性雰囲気中２
５０〜５００℃の温度範囲で加熱還元することを特徴と
する粒状マグネタイト粒子粉末の製造法。(1) Al synthesized from an aqueous solution containing Fe^2^+
or granular magnetite particles containing Si or Al and Si, granular magnetite particles synthesized from an aqueous solution containing Fe^2^+ whose particle surface is an Al compound or Si
A synthesized from an aqueous solution containing particles coated with the compound or both compounds and Fe^2^+
1 or Si or granular magnetite particles containing Al and Si, the particle surface of which is coated with the compound, is oxidized by heating in an oxidizing atmosphere in a temperature range of 350°C or more and less than 700°C. Granular maghemite-hematite composite particles containing Al or Si or Al and Si, granular maghemite-hematite composite particles whose particle surfaces are coated with the oxidized compound, or whose particle surfaces are coated with the oxidized compound. Granular maghemite/hematite composite particles containing Al or Si or Al and Si are prepared, and then the granular maghemite/hematite composite particles are heated in a reducing atmosphere for 2 hours.
A method for producing granular magnetite particle powder, characterized by carrying out thermal reduction in a temperature range of 50 to 500°C.
あらかじめ２００℃以上３５０℃未満の温度範囲で加熱
酸化しておくことを特徴とする請求項１記載の粒状マグ
ネタイト粒子粉末の製造法。(2) The method for producing granular magnetite particle powder according to claim 1, characterized in that prior to the thermal oxidation at 350° C. or higher and lower than 700° C., heating oxidation is performed in advance at a temperature range of 200° C. or higher and lower than 350° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29683390A JP2945460B2 (en) | 1990-10-31 | 1990-10-31 | Manufacturing method of granular magnetite particle powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29683390A JP2945460B2 (en) | 1990-10-31 | 1990-10-31 | Manufacturing method of granular magnetite particle powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04170325A true JPH04170325A (en) | 1992-06-18 |
| JP2945460B2 JP2945460B2 (en) | 1999-09-06 |
Family
ID=17838749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29683390A Expired - Fee Related JP2945460B2 (en) | 1990-10-31 | 1990-10-31 | Manufacturing method of granular magnetite particle powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2945460B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05213620A (en) * | 1991-09-13 | 1993-08-24 | Mitsui Mining & Smelting Co Ltd | Magnetite particles and its production |
-
1990
- 1990-10-31 JP JP29683390A patent/JP2945460B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05213620A (en) * | 1991-09-13 | 1993-08-24 | Mitsui Mining & Smelting Co Ltd | Magnetite particles and its production |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2945460B2 (en) | 1999-09-06 |
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