KR930002963B1 - Process for making gamma-ferrite powder contained cobalt - Google Patents
Process for making gamma-ferrite powder contained cobalt Download PDFInfo
- Publication number
- KR930002963B1 KR930002963B1 KR1019900021981A KR900021981A KR930002963B1 KR 930002963 B1 KR930002963 B1 KR 930002963B1 KR 1019900021981 A KR1019900021981 A KR 1019900021981A KR 900021981 A KR900021981 A KR 900021981A KR 930002963 B1 KR930002963 B1 KR 930002963B1
- Authority
- KR
- South Korea
- Prior art keywords
- cobalt
- reaction
- iron oxide
- powder
- ratio
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/706—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material
- G11B5/70626—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances
- G11B5/70642—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides
- G11B5/70652—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3
- G11B5/70668—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3 containing a dopant
- G11B5/70673—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the composition of the magnetic material containing non-metallic substances iron oxides gamma - Fe2 O3 containing a dopant containing Co
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
- C01G49/06—Ferric oxide (Fe2O3)
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
- C01P2002/52—Solid solutions containing elements as dopants
- C01P2002/54—Solid solutions containing elements as dopants one element only
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/42—Magnetic properties
Abstract
Description
제 1 도 본 발명 및 종래 방법에 따라 제조된 코발트 함유 자성산화철 분말의 반응시간에 따른 잔류저속밀도변화를 나타낸 그래프.1 is a graph showing the change in residual low speed density according to the reaction time of cobalt-containing magnetic iron oxide powder prepared according to the present invention and the conventional method.
제 2 도 본 발명 및 종래방법에 따라 제조된 코발트 함유 자성산화철 분말의 반응시간에 따른 보자력 변화를 나타낸 그래프.2 is a graph showing the coercive force change according to the reaction time of cobalt-containing magnetic iron oxide powder prepared according to the present invention and the conventional method.
본 발명은 자기기록 매체에 적합한 코발트 함유 자성산화철분말의 제조방법에 관한 것으로, 보다 상세하게는, 반응시 반응분위기를 적절히 조절함으로써 고보자력 및 고 잔류자속 밀도를 갖는 코발트함유 자성산화철 분말을 제조하는 방법에 관한 것이다. 코발트함유 자성산화철 분말은 현재 오디오, 비디오 테이프, 플로피 디스크, 하드디스크, 자기카드 중에 가장 널리 사용되고 있는 침상형 산화철 기록매체로서 자기기록재료 전체 생산액의 2/3를 점유하며 수요량은 계속 증가하고 있다. 코발트 자성산화철 분말은 침상형 산화철 분말의 형상 이방성에 코발트 원자의 높은 결정자기이방성을 부가하여 보자력을 대폭 향상시킨 것으로서, 고밀도 기록이 가능하고 고주파 영역에서 감도가 우수하다는 잇점을 가지고 있어 브티알(VTR) 테이프에 가장 많이 사용되고 있는 분말이다. 코발트함유 자성산화철의 종류는 제조방법에 따라, 도프형, 흡착형, 피착형으로 구분된다.The present invention relates to a method for producing a cobalt-containing magnetic iron oxide powder suitable for a magnetic recording medium, and more particularly, to prepare a cobalt-containing magnetic iron oxide powder having a high coercive force and a high residual magnetic flux density by appropriately adjusting the reaction atmosphere during the reaction. It is about a method. Cobalt-containing magnetic iron oxide powder is a needle-type iron oxide recording medium which is the most widely used among audio, video tape, floppy disk, hard disk, and magnetic card, accounting for two thirds of the total production value of magnetic recording material, and the demand is continuously increasing. Cobalt magnetic iron oxide powder adds high crystal magnetic anisotropy of cobalt atoms to the shape anisotropy of acicular iron oxide powder, which greatly improves coercive force. ) Most commonly used powder for tape. Types of cobalt-containing magnetic iron oxides are classified into dope, adsorptive and adhered types according to the production method.
상기 도프형은 코발트함유 자성산화철의 초기형태로서 결정자기이방성의 온도 의존성, 가압감자 및 전사에 의한 불안정성이 커서 실용화되지 않고 있는 형태이다. 또한, 상기 흡착형은 자기특성면에서는 고용형과 비슷하며 안정성은 고용형에 비해 다소개선되나 표면층에 밀집된 코발트 이온이 온도와 경시변화에 의해 내부로 확산이 용이하여 불안정성은 여전히 남아있는 형태이다. 또한, 상기 피착형은 코아(Core) 입자인-Fe2O3입자표면에 코발트 페라이트층을 형성시킨 것으로서, 제조방법은 제조조건에 따라 피착계와 에피탁시얼(epitaxial)계로 구분된다. 이러한 여러형태의 제조방법들 중 현재 실용화에 채택, 사용되어지고 있는 형태는 에피탁시얼계로서 코아(Core) 입자인-Fe2O3분말과 피착물질인 코발트 페라이트간의 결정구조 및 격자정수의 비슷함을 이용하여 고알칼리 용액중에서-Fe2O3입자표면상의 코발트 페라이트를 에피탁시얼 그로스(epitaxial growth)시켜 보자력을 증가시킴과 동시에 자기특성의 불안정성을 개선시킨 것이다. 이러한 에피탁시얼 그로스(epitaxial growht)법은 시드(Seed)인-Fe2O3분말을 코발트 및 제일철염 용액중에 분산시킨 후 알카리용액을 가하여-Fe2O3표면상에 코발트-철 산화물을 에피탁시얼 성장시킴으로써, 코발트 함유 산화철 자성분말을 제조하는 방법이다.The dope type is an initial form of cobalt-containing magnetic iron oxide, which is not practical because of its large temperature dependence of magneto-anisotropy, instability due to pressurized potatoes and transfer. In addition, the adsorption type is similar to the solid solution type in terms of magnetic properties, and the stability is somewhat improved compared to the solid solution type, but cobalt ions concentrated in the surface layer are easily diffused into the interior due to temperature and time-dependent change, and thus, instability remains. In addition, the adherend is a core (Core) particles A cobalt ferrite layer is formed on the surface of a -Fe 2 O 3 particle, and the manufacturing method is classified into an adherent system and an epitaxial system according to the production conditions. Among these various types of manufacturing methods, the type currently adopted and used for practical use is epitaxial system, which is a core particle. The crystal structure and the lattice constant between -Fe 2 O 3 powder and cobalt ferrite as an adherent material were used in high alkaline solution. Cobalt ferrite on the surface of -Fe 2 O 3 particles was epitaxially grown to increase coercive force and improve instability of magnetic properties. This epitaxial growht method is seed. -Fe 2 O 3 powder was dispersed in cobalt and ferrous salt solution, and then alkaline solution was added A cobalt-containing iron oxide magnetic powder is prepared by epitaxially growing cobalt-iron oxide on a -Fe 2 O 3 surface.
상기의 에피탁시얼 그로스(epitaxial growht)법의 종래기술을 요약하면 다음과 같다. 시드(Seed)인-Fe2O3를 수중에 잘 분산시킨 후 적정비율의 코발트염과 제일철염을 첨가한 다음 알카리를 가하여 산화성분 위기 및 비산화성 분위기하에서 50℃이상의 반응온도로 수시간 반응시켜 코발트 에피탁시얼-Fe2O3분말을 제조하는 공정으로서 이를 보다 구체적으로 나타내면 대략 다음과 같은 제조조건으로 행하여 지고 있다.The prior art of the epitaxial growht method is summarized as follows. Seed Inn After dispersing -Fe 2 O 3 well in water, cobalt salt and ferrous salt in an appropriate ratio are added, and then alkali is added, followed by reaction for several hours at a reaction temperature of 50 ° C. or higher under an oxidative crisis and a non-oxidizing atmosphere. As a process for producing -Fe 2 O 3 powder, this is more specifically performed under the following manufacturing conditions.
상기의 각 제조조건들은 최종 Co--Fe2O3의 특성에 큰 영향을 미치므로 이들 반응조건들의 제어가 대단히 중요하다. 제일철염과 코발트염의 첨가 비율에 따라 강자성 산화물, 강자성과 비강자성 혼합 산화물(1.3〈x〈2), 비강자성 산화물(x〉2), 옥시수산화물등이 생성된다고 알려져 있다(일본특허소 55-90422). 또한, 제일철염과 코발트염의 침전제인 알카리 첨가량, 반응물질의 첨가반응 순서에 따라서도 최종 Co--Fe2O3의 보자력에 큰 영향을 미치는 것으로 알려져 있다(일본특허 소 55-20278, 56-134523). 그러나, 상기 종래의 제조방법은 보자력 및 잔류자속밀도가 낮을뿐만 아니라 코발트 이외의 다량의 2가금속이온 및 기타 첨가제를 사용하여야 하는 문제점이 있다. 이에, 본 발명의 목적은 코발트 에피탁시(epitaxy) 반응시 반응분위기를 조절함으로써, 고보자력 및 고잔류자속밀도를 갖는 코발트 함유 자성산화철을 제조하는 방법을 제공하고자 하는 것으로, 특히, 에피탁시얼 그로스(epitaial growth) 반응시 반응 분위기를 적절히 조절함으로써 2가(Ⅱ) 금속이온 및 기타 첨가제를 사용하지 않고서도 우수한 자기특성을 갖는 코발트함유 침상산화철의 제조방법을 제공하고자 하는 것이다.Each of the above manufacturing conditions is the final Co- The control of these reaction conditions is very important because it greatly affects the properties of -Fe 2 O 3 . Ferromagnetic oxide depending on the ratio of ferrous salt and cobalt salt added , Ferromagnetic and nonferromagnetic mixed oxides (1.3 <x <2), nonferromagnetic oxides (x> 2), oxyhydroxides It is known that the back light is produced (Japanese Patent No. 55-90422). In addition, depending on the amount of alkali, which is a precipitant of ferrous and cobalt salts, and the reaction order of addition of the reactants, It is known to have a great influence on the coercive force of -Fe 2 O 3 (Japanese Patent Nos. 55-20278, 56-134523). However, the conventional manufacturing method has a problem that not only low coercive force and residual magnetic flux density but also use a large amount of divalent metal ions and other additives other than cobalt. Accordingly, an object of the present invention is to provide a method for producing a cobalt-containing magnetic iron oxide having a high coercive force and a high residual magnetic flux density by controlling the reaction atmosphere during the cobalt epitaxy reaction, in particular, epitaxy It is to provide a method for producing cobalt-containing acicular iron oxide having excellent magnetic properties without using divalent (II) metal ions and other additives by appropriately adjusting the reaction atmosphere during the earl growth (epitaial growth) reaction.
이하, 본 발명에 대하여 설명한다.EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.
본 발명은 에피탁시얼 그로스(epitaxial growth)법으로 자기기록용 자성산화철 분말을 제조하는 방법에 있어서, 시드(Seed)인-Fe2O3에 대한 분산물량의 비(H2O/-Fe2O3)가 무게비로 6.0이하가 되도록 물에-Fe2O3분말을 투입하여 잘 분산시킨 다음, 여기에, 제일철염에 대한 코발트 염의 비(Co(Ⅱ)/Fe(Ⅱ))가 몰비로 0.5-0.77이 되도록 코발트염 및 제 1 철염을 첨가하고, 이어서, 침전제로서 알칼리인 수산화나트륨을의 당량비가 1.0이상이 되게 첨가한 다음, 승온시, 반응온도까지는 비사화성 분위기를 유지하고 반응온도이상에서는 산화성분위기를 유지하여 코발트함유 자성산화철 분말을 제조하는 방법에 관한 것이다.The present invention relates to a method for producing magnetic iron oxide powder for magnetic recording by an epitaxial growth method, which is a seed. The ratio of the amount of dispersion to -Fe 2 O 3 (H 2 O / -Fe 2 O 3 ) in water so that it is 6.0 or less by weight -Fe 2 O 3 powder was added and dispersed well, and then cobalt salt and ferrous salt were added so that the ratio of cobalt salt to ferrous salt (Co (II) / Fe (II)) was 0.5-0.77 in molar ratio. And then sodium hydroxide which is alkali as precipitant The present invention relates to a method for preparing cobalt-containing magnetic iron oxide powder by adding an equivalent ratio of not less than 1.0, and then maintaining a non-digestible atmosphere until the reaction temperature, and maintaining an oxidizing component atmosphere above the reaction temperature.
이하, 본 발명에 대하여 상세히 설명한다.EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.
본 발명에 있어 시드(Seed)로 사용되는 상기-Fe2O3분말은 게타이트(Goethite)를 탈수, 환원, 산화하여 제조한 것을 사용하는 것이 바람직하다. 또한, 상기 반응시, 반응전(全) 단계를 산화성 분위기로 한 경우는 산화속도의 제어가 용이하게 않다는 문제점이 있다. 즉 슬러리의 산화속도가 빨라짐에 따라-Fe2O3표면에서부터 생성되는 CoxFe3-xO4의 핵생성 속도보다 용액중에서 용존하는 산소에 의한 다수의 핵이 생성하게 되어 빠른 속도로 결정화가 진행되어 완전한 피착에 의한 에피탁시얼 그로스(epitaxial growth)가 곤란하게 된다. 또한 승온시에 빠른속도의 산화는 게타이트(α-FeOOH), 마그네타이트(Fe3O4)등의 불순물 생성을 가능하게 함으로서, 피착의 방해요인 및 피착증에 고용 또는 분리생성하여 자기특성을 저하하는 원인이 된다.Said used as a seed in the present invention It is preferable to use -Fe 2 O 3 powder prepared by dehydration, reduction and oxidation of goethite. In addition, there is a problem that the control of the oxidation rate is not easy when the entire step before the reaction is made into an oxidizing atmosphere. In other words, as the oxidation rate of the slurry increases The nucleation rate of oxygen dissolved in the solution is greater than the nucleation rate of CoxFe 3 -xO 4 generated from the surface of -Fe 2 O 3, and crystallization proceeds at a rapid rate. epitaxial growth becomes difficult. In addition, rapid oxidation at elevated temperatures enables the production of impurities such as gettite (α-FeOOH) and magnetite (Fe 3 O 4 ), and thus reduces the magnetic properties by solid solution or separation of deposition barriers and deposition. It causes.
한편, 반응전단계를 비산화성 분위기로 한 경우는 피착증을 구성하는 CoxFe3xO4의 결정구조가 산소의 결핍으로 인하여 결정구조가 다소 불안정하게되며, 이로인하여 결정자기이방성의 저하에 원인이 된다. 따라서 우수한 자기적 특성값을 갖는 코발트 함유 자성산화철을 제조하기 위해 본 발명에서는 승온식 상기 반응 분위기를 조절한 것이다.On the other hand, when the pre-reaction step is a non-oxidizing atmosphere, the crystal structure of CoxFe 3 xO 4 constituting the deposition becomes somewhat unstable due to the lack of oxygen, which causes a decrease in crystal anisotropy. Therefore, in order to manufacture cobalt-containing magnetic iron oxide having excellent magnetic property values, the reaction temperature is controlled by the elevated temperature type.
이하, 본 발명을 실시예에 의하여 보다 상세하게 설명한다.Hereinafter, the present invention will be described in more detail with reference to Examples.
[실시예 1]Example 1
[발명예 1-4]Invention Example 1-4
시드(Seed)인-Fe2O3는 길이 0.3-0.4㎛, 침상비 약 10 : 1를 나타내며 자기특성은 보자력 353(Oe), 잔류자속밀도 34(emu/g)의 특성을 나타내는 분말을 출발물로 사용하였다. 출발물인 상기-Fe2O3분말 34g을 102ml의 증류수에 넣고 비산화성 가스를 3L/min로 불어넣으면서 잘 분산시킨후 1몰 농도의 CoCl2ㆍ6H2O29ml를 우선 첨가하고 1몰농도 NaOH 500ml를 첨가하여 먼저 코발트 수산화물을 침전시켰다. 여기에 1몰농도 FeCl2ㆍ4H20 56㎛載을 첨가하여 제일철 수산화물을 침전시켰더니, 시드(Seed)인-Fe2O3의 색인 갈색현탁액이 되었다. 이 현탁액을 비산화성 분위기상태로 유지하면서 50℃까지 승온시킨다음, 분위기를 산화성 분위기로 대체한후 90℃까지 승온시켜 3시간 반응시켰다. 반응후 30분 경과시 갈색현탁액은 흑색 현탁액으로 변화하였다. 반응종료후 반응용기내에서 50℃까지 서냉한 다음 수세여과하고 아세톤으로 재세정한 후 60℃로 건조하여 흑색산화철 분말을 얻었다. 반응시간 1시간 간격으로 샘플을 채취하고 VSM을 이용하여 측정한 자기적 특성 값 및 그 변화를 관찰하고, 하기 표1에 그 결과를 나타내었다.Seed Inn -Fe 2 O 3 has a length of 0.3-0.4㎛, needle ratio of about 10: 1 and a powder having magnetic properties of 353 (Oe) and residual magnetic flux density 34 (emu / g) was used as a starting material. The starting point Dissolve 34g of Fe 2 O 3 powder in 102ml of distilled water and disperse well while blowing non-oxidizing gas at 3L / min, add 1 mol of CoCl 2 ㆍ 6H 2 O29ml first, and then add 1 mol of NaOH 500ml. Cobalt hydroxide was precipitated. 1 mol of FeCl 2 · 4H 2 0 56㎛ 載 was added thereto to precipitate ferrous hydroxide, which was seeded. This index was brown suspension of -Fe 2 O 3. The suspension was heated to 50 ° C. while being kept in a non-oxidizing atmosphere, and then replaced with an oxidizing atmosphere, then heated up to 90 ° C. for 3 hours. Thirty minutes after the reaction, the brown suspension turned into a black suspension. After completion of the reaction, the reaction vessel was slowly cooled to 50 ° C., washed with water, washed with acetone, and dried at 60 ° C. to obtain black iron oxide powder. Samples were taken at 1 hour intervals of the reaction time and the magnetic property values measured using VSM and their changes were observed. The results are shown in Table 1 below.
[비교예 1-4][Comparative Example 1-4]
반응시작으로부터 종료까지 반응분위기를 비산화성 분위기로 처리하는 것을 제외하고는 상기 발명예와 동일한 방법으로 실시하고 그 결과를 하기표1에 나타내었다.Except for treating the reaction atmosphere from the start to the end of the reaction in a non-oxidizing atmosphere was carried out in the same manner as in the invention example and the results are shown in Table 1 below.
[비교예 5-8][Comparative Example 5-8]
반응시작으로부터 종료시까지 반응분위기를 산화성분위기로 처리하는 것을 제외하고는 상기 발명예와 동일한 방법으로 실시하고, 그 결과를 하기표1에 나타내었다.Except for treating the reaction atmosphere from the start of the reaction to the end of the reaction with the oxidizing component crisis was carried out in the same manner as in the invention example, the results are shown in Table 1 below.
[표 1]TABLE 1
상기 표1의 발명예(1-4)와 비교예(1-8)의 보자력 및 잔류자속밀도를 보다 명확히 비교하기 위해 그 값들을 제 1 도 및 제 2 도에 나타내었다.In order to more clearly compare the coercive force and residual magnetic flux density of Inventive Example (1-4) and Comparative Example (1-8) of Table 1, the values are shown in FIGS. 1 and 2.
상기 표1 및 제 1 도 및 제 2 도에 나타난 바와같이, 본 발명에 부합되는 발명예(1-4)가 비교예(1-8)에 비하여 훨씬 우수한 보자력 및 잔류자속밀도를 나타내고 있음을 알 수 있다.As shown in Table 1 and FIGS. 1 and 2, it can be seen that Inventive Example (1-4) according to the present invention exhibits much better coercive force and residual magnetic flux density than Comparative Example (1-8). Can be.
[실시예 2]Example 2
[발명예 5]Invention Example 5
시드(Seed)인-Fe2O3의 입자특성은 길이 0.3-0.4ml, 침상비가 약 10 : 1를 나타내며 자기특성은 보자력 336(Oe), 잔류자속밀도 33(emu/g)의 특성을 나타내는 분말을 출발물로 사용한 것을 제외하고는 실시예 1의 발명예와 동일한 방법으로 30분간 반응시켜 실시하였다. 반응완료후 현탁액의 색은 흑색 현탁액으로 변화하였으며 VSM을 이용하여 측정한 자기특성값을 하기표 2에 나타내었다.Seed Inn The particle characteristics of -Fe 2 O 3 were 0.3-0.4ml in length and the needle ratio was about 10: 1, and the magnetic properties were starting from powders with characteristics of coercive force 336 (Oe) and residual magnetic flux density 33 (emu / g). Except what was used, it reacted for 30 minutes by the same method as the invention example of Example 1. After completion of the reaction, the color of the suspension was changed to a black suspension, and the magnetic property values measured using the VSM are shown in Table 2 below.
[비교예 9]Comparative Example 9
반응시작으로부터 종료까지 반응분위기를 비산화성 분위기로 처리하는 것을 제외하고는 실시예 1의 발명예와 동일한 방법으로 30분간 반응시켜 실시하여 그 결과를 측정하여 하기표 2에 나타내었다.Except for treating the reaction atmosphere from the start to the end of the reaction in a non-oxidizing atmosphere was carried out by reacting for 30 minutes in the same manner as the invention example of Example 1 and the results are shown in Table 2 below.
[비교예 10]Comparative Example 10
출발물인-Fe2O3분말 34g을 102ml의 증류수에 넣고 산화성 가스를 31/min로 불어넣으면서 잘 분산시켜 슬러리화 한후-Fe2O3슬러리를 90℃로 가열시킨 상태에서 1몰농도 CoCl2ㆍ6H2O 29ml를 첨가하고 1몰농도 NaOH 500ml를 첨가하여 먼저 코발트 수산화물을 침전시켰다. 여기에 1몰농도 FeCl2ㆍ4H20 56ml를 첨가하여 제일철 수산화물을 침전시켰더니, 시드(Seed)인-Fe2O3의 색인 갈색현탁액이 되었다. 이 현탁액을 90℃로 유지하면서 30분간 반응시킨 결과 약간의 검은색을 띠는 현탁액으로 변화하였으며, 그 결과를 측정하여 하기표 2에 나타내었다.Starting point 34 g of -Fe 2 O 3 powder was poured into 102 ml of distilled water, and dispersed well while blowing oxidizing gas at 31 / min. By adding a -Fe 2 O 3 concentration in the slurry state it was heated to 90 ℃ per mol CoCl 2 6H 2 O 29ml was added and a 1 molar NaOH 500ml were first precipitate cobalt hydroxide. 56 ml of 1 mol of FeCl 2 4H 2 0 was added thereto to precipitate ferrous hydroxide. This index was brown suspension of -Fe 2 O 3. The suspension was reacted for 30 minutes while maintaining the suspension at 90 ° C. The result was a slight black suspension. The results were measured and shown in Table 2 below.
[비교예 11]Comparative Example 11
90℃로 가열한-Fe2O3슬러리에 첨가하는 CoCl2, NaOH, FeCl2의 용액온도도 90℃로 한것을 제외하고는 비교예 9와 동일한 방법으로 실시하였다. 반응완료후 현탁액의 색은 약간의 검은색을 나타내었으며, 그 자기적특성 결과를 측정하여 하기표 2에 나타내었다.Heated to 90 ℃ The solution temperature of CoCl 2 , NaOH and FeCl 2 added to the -Fe 2 O 3 slurry was also set to 90 ° C., in the same manner as in Comparative Example 9. After completion of the reaction, the suspension was slightly black in color, and the magnetic properties were measured and shown in Table 2 below.
[표 2]TABLE 2
상기 표2에 나타낸 바와같이, 반응전단계를 산화성 및 비산화성 분위기로 처리한 비교예(9-11)에 비해 본 발명에 따라 반응분위기를. 제1, 2단계로 구분하여 반응시작으로부터 승온시까지는 비산화성 분위기, 반응온도에서는 산화성분위기로 유지한 본 발명예(5)가 보자력 및 잔류자속밀도에 있어 우수함을 알 수 있다.As shown in Table 2, the reaction atmosphere according to the present invention compared to Comparative Example (9-11) in which the pre-reaction step was treated with an oxidizing and non-oxidizing atmosphere. It can be seen that Example (5) of the present invention maintained in the non-oxidizing atmosphere and the oxidative component crisis at the reaction temperature from the start of the reaction to the temperature increase in the first and second stages is excellent in the coercive force and the residual magnetic flux density.
상술한 바와같이, 본 발명은 종래방법에 비해 보자력 및 잔류자속밀도가 높은 코발트 함유 침상형의 자성산화철분말을 제조할 수 있는 효과가 있는 것이다.As described above, the present invention has the effect of producing cobalt-containing acicular magnetic iron oxide powder having a higher coercive force and a higher residual magnetic flux density than the conventional method.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019900021981A KR930002963B1 (en) | 1990-12-27 | 1990-12-27 | Process for making gamma-ferrite powder contained cobalt |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019900021981A KR930002963B1 (en) | 1990-12-27 | 1990-12-27 | Process for making gamma-ferrite powder contained cobalt |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR920011923A KR920011923A (en) | 1992-07-25 |
| KR930002963B1 true KR930002963B1 (en) | 1993-04-16 |
Family
ID=19308614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1019900021981A KR930002963B1 (en) | 1990-12-27 | 1990-12-27 | Process for making gamma-ferrite powder contained cobalt |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR930002963B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100442541B1 (en) * | 2001-09-12 | 2004-07-30 | 주식회사 페로엔텍 | Method for preparing magnetite in aqueous solution at room temperature and Method for water-waste-treatment using the said magnetite |
-
1990
- 1990-12-27 KR KR1019900021981A patent/KR930002963B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR920011923A (en) | 1992-07-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1039050A (en) | Magnetic iron oxides with improved orientability and a process for their production | |
| US4202871A (en) | Production of acicular ferric oxide | |
| EP0377933B1 (en) | Magnetic iron oxide particles and method of producing the same | |
| US3897354A (en) | Cobalt-containing acicular ferrimagnetic iron oxide of improved remanence stability | |
| JPS5853688B2 (en) | Method for producing acicular alloy magnetic particle powder mainly composed of Fe-Mg | |
| JP3087825B2 (en) | Spindle-shaped goethite particle powder, method for producing the same, spindle-shaped metal magnetic particle powder containing iron as a main component obtained using the goethite particle powder as a starting material, and method for producing the same | |
| US4820433A (en) | Magnetic powder for magnetic recording | |
| KR930002963B1 (en) | Process for making gamma-ferrite powder contained cobalt | |
| US4396596A (en) | Method of preparing gamma ferric hydroxyoxide powder | |
| US4457955A (en) | Process for producing magnetizable particles | |
| KR890001971B1 (en) | Process for producing cobalt-containing magnetic iron oxide powder | |
| US5399278A (en) | Process for producing acicular goethite particles and acicular magnetic iron oxide particles | |
| US4086174A (en) | Cobalt modified acicular γ ferric oxide and process for preparing the same | |
| JPS5835241B2 (en) | Method for producing alloy magnetic powder mainly composed of iron and copper | |
| JPH0633116A (en) | Ferromagnetic metallic powder for magnetic recording medium and production thereof | |
| JPH10245233A (en) | Spindle-like hematite particle and its production and spindle-like metal magnetic particle containing iron as main component and obtained from the hematite particle as starting ram material and its production | |
| KR930011235B1 (en) | Magnetic materials | |
| JP2582764B2 (en) | Method for producing acicular ferromagnetic metal powder consisting essentially of iron | |
| US5480571A (en) | Process for producing acicular goethite particles and acicular magnetic iron oxide particles | |
| GB2111471A (en) | Process for the preparation of acicular -feooh | |
| KR970002095B1 (en) | Method of magnetic powder | |
| JP2931182B2 (en) | Method for producing acicular γ-FeOOH | |
| JPH107420A (en) | Granule of cobalt-coated needle-shaped magnetic oxide of iron | |
| KR940009930B1 (en) | Process for the preparation of cobalt ferrite expitaxial iron oxid powder | |
| JPS58135135A (en) | Preparation of powder of needle-like crystal of iron beta-oxyhydroxide particle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| G160 | Decision to publish patent application | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 19971229 Year of fee payment: 6 |
|
| LAPS | Lapse due to unpaid annual fee |