KR930004584B1 - Process for the preparation of magnetic iron oxides and the pigments obtained therefrom - Google Patents

Process for the preparation of magnetic iron oxides and the pigments obtained therefrom Download PDF

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KR930004584B1
KR930004584B1 KR1019890019226A KR890019226A KR930004584B1 KR 930004584 B1 KR930004584 B1 KR 930004584B1 KR 1019890019226 A KR1019890019226 A KR 1019890019226A KR 890019226 A KR890019226 A KR 890019226A KR 930004584 B1 KR930004584 B1 KR 930004584B1
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cobalt
coated
coating
core
iron oxide
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KR900009888A (en
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카트라인 헨드릭
키믈레 페테르
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바이엘 아크티엔게젤샤프트
루디 마이어,요아힘 그렘
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
    • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/22—Compounds of iron
    • C09C1/24—Oxides of iron
    • 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
    • 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
    • G11B5/70678—Ferrites
    • G11B5/70684—Ferro-ferrioxydes
    • G11B5/70694—Non-stoechiometric ferro-ferrioxydes, e.g. berthollide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/30—Three-dimensional structures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
    • C01P2004/82—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
    • C01P2004/84—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other

Abstract

내용 없음.No content.

Description

자성 산화철의 제조방법 및 이로부터 수득되는 안료Method for producing magnetic iron oxide and pigment obtained therefrom

본 발명은 코발트를 함유하는 자성 산화철 안료의 제조방법 및 이로부터 수득되는 안료에 관한 것이다.The present invention relates to a process for the preparation of magnetic iron oxide pigments containing cobalt and to pigments obtained therefrom.

r-Fe2O3자성 안료는 보자력이 약 31kA/m이하이고, 페라이트 자성 안료는 약 35kA/m이하이다. 보자력이 매우 높은 자성 안료는 오디오, 비데오 및 데이타 저장분야에서 저장 밀도가 큰 시그날의 자성 기록용으로 사용이 증가되고 있다. 자성 산화철의 보자력을 향상시키는 다양한 방법이 공지되어 있다.The r-Fe 2 O 3 magnetic pigment has a coercive force of about 31 kA / m or less and a ferrite magnetic pigment of about 35 kA / m or less. Magnetic pigments with very high coercivity are increasingly used for magnetic recording of signals with high storage densities in audio, video and data storage applications. Various methods of improving the coercive force of magnetic iron oxide are known.

독일연방공화국 특허문헌 제DE-A29 03 593호에 따르면, α-FeOOH전구체 화합물을 코발트로 도핑하여 보자력이 높은 안료를 수득한다. 코발트 1% 및 FeO 20%를 사용하여 약 50kA/m의 보자력장 세기를 얻는다. 이러한 안료에서 발견되는 단점은 프린트 쓰루(print through)값이 낮고 자력 안정성이 불충분하며 보자력의 온도 의존성이 높다는 점이다.According to DE-A29 03 593 of the Federal Republic of Germany, the α-FeOOH precursor compound is doped with cobalt to obtain a pigment having high coercivity. A coercive field strength of about 50 kA / m is obtained using 1% cobalt and 20% FeO. Disadvantages found in these pigments are low print through values, insufficient magnetic stability and high temperature dependence of the coercivity.

높은 보자력을 얻는 다른 방법이 독일연방공화국 특허문헌 제DE-A 22 35 383호에 기술되어 있으며, 이에 따라, 코발트 페라이트 층을 강한 알칼리성 매질 속에서 자성 산화철의 코어에 상위적으로 결정화시킨다. 이들 안료는 코발트 도핑된 안료보다 프린트 쓰루(print through)와 자력 안정성이 더 우수하지만, 이들의 스위칭 장 분포와 테입에서 발생하는 노화 말소성에 있어서 완전히 만족스럽지는 않다.Another method of obtaining high coercivity is described in DE-A 22 35 383, whereby the cobalt ferrite layer is crystallized to the core of the magnetic iron oxide in a strong alkaline medium. These pigments have better print through and magnetic stability than cobalt doped pigments, but are not completely satisfactory in their switching field distribution and aging quenching occurring in the tape.

정자기성이 개선된 자성 산화철의 제조방법이 독일연방공화국 특허문헌 제 DE-A 20 36 612호, 제DE-A 22 43 231호, 제DE-A 24 10 517호 및 제DE-A 22 89 344호에 기술되어 있다. 이들 방법에서는 코발트 화합물, 일반적으로 수산화코발트를 산화철 코어 물질의 표면에 침전시킨다. 이후에 코발트가 코어 물질의 표면 근처 영역 속에 분산되도록 적절히 수행한다.Methods for producing magnetic iron oxide with improved magnetic properties are described in the Federal Republic of Germany Patent Documents DE-A 20 36 612, DE-A 22 43 231, DE-A 24 10 517 and DE-A 22 89 344 Described in the heading. In these methods cobalt compounds, generally cobalt hydroxide, are precipitated on the surface of the iron oxide core material. The cobalt is then suitably carried out to disperse in the region near the surface of the core material.

정자기성을 개선하기 위해 산화철 코어 물질 위에 코발트 화합물과 철 화합물을 따로따로 수개의 층으로 피복시키는 방법이 독일연방공화국 특허문헌 제DE-A 35 20 210호, 제DE-A 36 31 193호 및 제DE-A 33 44 299호에 기술되어 있다.In order to improve the magnetic properties, a method of coating the iron oxide core material with the cobalt compound and the iron compound separately in several layers is disclosed in DE-A 35 20 210 and DE-A 36 31 193 and It is described in DE-A 33 44 299.

안료의 정자기성을 상기에서 언급한 방법들중의 어떤 것으로 개선할 수 있지만, 이들 방법들은 모두 높은 보자력과 양호한 스위칭 장 분포의 결합이 100℃이상의 열처리를 수행함으로써만 성취할 수 있고, 이것은 산화물의 자력 안정성에 역효과를 미친다는 단점을 갖는다.Although the magnetostaticity of the pigment can be improved by any of the above-mentioned methods, all of these methods can be achieved only by the combination of high coercivity and good switching field distribution by performing heat treatment above 100 ° C. It has the disadvantage of adversely affecting the magnetic stability.

따라서, 상기한 단점들이 없는, 자성 산화철 안료를 제조하기 위한 개선된 방법을 찾는데 어려움이 있다.Thus, there is a difficulty in finding an improved method for producing a magnetic iron oxide pigment, which is free from the above disadvantages.

놀랍게도, 본 발명에 따라 이러한 요구들이 코어물질로서 사용하는 자성 산화철 안료를 먼저 조성이 CoxFeII 1-xFeIIIO4(0≤x≤1)인 코발트 페라이트, 또는 코발트를 함유하는 버톨리드(berthollid)화합물로 한층을 피복시킨 다음, 추가의 코발트 화합물로 피복시키는, 코발트 화합물 피복 물질을 갖는 자성 산화철 안료의 제조방법에 의해 충족되는 것으로 밝혀졌다. 이 방법이 본 발명의 주제이다.Surprisingly, the magnetic iron oxide pigments used in accordance with the present invention as core material are first cobalt ferrite having a composition of Co x Fe II 1-x Fe III O 4 (0≤x≤1), or buttolide containing cobalt. It has been found to be satisfied by a process for the preparation of magnetic iron oxide pigments with a cobalt compound coating material, which is coated with a (berthollid) compound and then with an additional cobalt compound. This method is the subject of the present invention.

본 발명의 방법은 1단계에서 조성이 FeOx(여기서, x는 1.33 내지 1.5이다)인 자성 산화철 코어, 입자 물질을 코발트를 함유하는 버톨리드 물질 또는 조성이 CoxFeIII 1-xFeIIIO4(여기서, x는 0보다 크고 1보다 작거나 같다)인 예비 피복 물질로 피복시킨 후, 2단계에서 예비 피복된 입자를 코발트 화합물로 피복시킴을 포함하여 자성 산화철 안료를 제조하는 것이다.The process of the present invention comprises a magnetic iron oxide core having a composition of FeOx (where x is 1.33 to 1.5) in one step, a butoxide material containing cobalt as the particulate material or a composition of Co x Fe III 1-x Fe III O 4 After coating with a precoat material of which x is greater than 0 and less than or equal to 1, the magnetic iron oxide pigment is prepared by coating the precoated particles in step 2 with a cobalt compound.

사용하는 자성 산화철 코어 물질은 r-Fe2O3안료, Fe3O4안료 또는 조성이 FeOx(1.33≤x≤1.5)인 버톨리드 화합물일 수 있다. 이들 산화철은 P, Zn, B, Si, Sn, Ge, Al, Mn, Cr, Ni, Mg 및 Ca로 이루어진 그룹으로부터 하나 이상의 원소를 수반할 수 있다.The magnetic iron oxide core material to be used may be an r-Fe 2 O 3 pigment, a Fe 3 O 4 pigment or a butoxide compound having a composition of FeOx (1.33 ≦ x ≦ 1.5). These iron oxides may carry one or more elements from the group consisting of P, Zn, B, Si, Sn, Ge, Al, Mn, Cr, Ni, Mg and Ca.

본 발명에 따라, 코어를 먼저 Fe(III)의 함량이 0 내지 67%인 철(II,III)염 및 코발트염으로 피복시킨다. 예비 피복 물질의 도포는 보다 바람직하게는 알칼리성 매질속에서 수행한다. 피복은 하기의 방법에 따라 수행할 수 있다 : 산화철 코어 물질을 물 속에 분산시키고 철염, 코발트염 또는 이의 용액 및 알칼리성 용액을 가한다. 알칼리성 용액은 산화철 코어 물질의 분산 전후 및 철 및 코발트염 용액의 첨가 전후에 가할 수 있다.According to the invention, the core is first coated with iron (II, III) salts and cobalt salts with a content of Fe (III) 0 to 67%. Application of the precoat material is more preferably carried out in an alkaline medium. The coating can be carried out according to the following method: The iron oxide core material is dispersed in water and iron salt, cobalt salt or a solution thereof and an alkaline solution are added. The alkaline solution can be added before or after the dispersion of the iron oxide core material and before or after the addition of the iron and cobalt salt solutions.

예비 피복은 산화 조건하에서, 예를 들면, 공기를 산화제에서 사용하여, 철염 용액과 함께 도입된 철(II)이온이 부분적으로 또는 완전히 산화되도록 수행할 수 있다. 또한, 불활성 조건하에서 공정을 수행할 수 있으며, 이러한 경우, 예비 피복 물질의 층의 철(II) 이온이 코어 물질의 철(III)이온에 의해 산화되는 것으로 추측된다.The pre-coating can be carried out under oxidizing conditions, for example by using air in an oxidant such that the iron (II) ions introduced with the iron salt solution are partially or completely oxidized. It is also possible to carry out the process under inert conditions, in which case it is assumed that the iron (II) ions in the layer of the precoat material are oxidized by the iron (III) ions of the core material.

예비 피복 공정에 있어서, 물질을 바람직하게는 20℃ 내지 비점의 온도에서 Fe(II)가 용액 속에 잔존하지 않을때까지 교반한다.In the pre-coating process, the material is stirred at a temperature preferably between 20 ° C. and boiling point until no Fe (II) remains in solution.

코발트-철 화합물의 피복은 안료 현탁액에 코발트염 또는 알칼리성 용액을 첨가함으로써 코발트 화합물을 피복하여 수행한다. 코발트를 사용하는 피복은 산화조건 또는 불활성 조건하에서 수행할 수 있다.Coating of the cobalt-iron compound is carried out by coating the cobalt compound by adding a cobalt salt or an alkaline solution to the pigment suspension. Coating using cobalt can be carried out under oxidizing or inert conditions.

사용하는 코발트 화합물로서는 Co(II)염, 특히 CoSO4·7H2O가 적절하다. 피복을 Co함량이 공정에 투입되는 코어 물질을 기준으로 하여 0.5 내지 10%인 조건하에 수행하는 경우에 특히 양호한 결과를 얻는다.As the cobalt compound to be used, Co (II) salt, in particular CoSO 4 · 7H 2 O, is suitable. Particularly good results are obtained when the coating is carried out under conditions with a Co content of 0.5 to 10% based on the core material fed into the process.

코발트 피복은 바람직하게는 알칼리성 매질속에서 수행한다. 철/코발트 화합물 및 코발트 화합물로 피복시키는 동안의 OH농도는 0.1 내지 10mol/ℓ, 바람직하게는 0.3 내지 5mol/ℓ이다.Cobalt coating is preferably carried out in alkaline media. The OH concentration during coating with the iron / cobalt compound and the cobalt compound is 0.1 to 10 mol / l, preferably 0.3 to 5 mol / l.

현탁액 속의 코어 물질의 고체 함량은 30g/ℓ 내지 200g/ℓ, 바람직하게는 50 내지 150g/ℓ이다. 예비 피복층에 피복되는 코발트 페라이트의 양은 사용하는 코어 물질의 2 내지 25%이다.The solids content of the core material in the suspension is 30 g / l to 200 g / l, preferably 50 to 150 g / l. The amount of cobalt ferrite coated on the precoat layer is 2 to 25% of the core material used.

안료 현탁액은 여과, 세척 및 건조시켜 가공한다.Pigment suspensions are processed by filtration, washing and drying.

본 발명은 또한 본 발명에 따르는 방법으로 수득할 수 있는 안료에 관한 것이다. 안료를 100℃이상의 열처리 없이 수득하기 때문에, 자력 안정성이 양호한 것이 특징이다.The invention also relates to pigments obtainable by the process according to the invention. Since the pigment is obtained without heat treatment of 100 ° C. or higher, it is characterized by good magnetic stability.

본 발명을 하기의 실시예로 예시하지만, 이에 제한받지 않는다.The invention is illustrated by the following examples, without however being limited thereto.

분말 샘플의 자력 데이타는 398kA/m의 자기장에서 샘플 진동 자력계로 측정한다.Magnetic data of powder samples is measured with a sample vibration magnetometer at a magnetic field of 398 kA / m.

본 발명에 따른 산화철 안료의 정자기성을 측정하기 위해, 관찰할 안료를 PVC/PVA계 랙커 속에 분산시키고 폴리에스테르 시트에 박층으로 피복시킨다. 안료를 80kA/m의 균일한 자기장 속에서 배향시킨 후에, 시험 테입을 60℃에서 경화시킨다. 이후에 이것을 자르고 샘플 진동 자력계로 하기의 데이타를 얻는다 :In order to measure the magnetomagnetic properties of the iron oxide pigments according to the invention, the pigments to be observed are dispersed in a PVC / PVA based racker and coated in a thin layer on a polyester sheet. After the pigment is oriented in a uniform magnetic field of 80 kA / m, the test tape is cured at 60 ° C. This is then cut off and the sample vibration magnetometer gives the following data:

iHc 398kA/m에서 측정한 보자력Coercivity measured at iHc 398kA / m

Mr/ms 잔류 자기화/포화 자기화Mr / ms residual magnetization / saturation magnetization

SFD 스위칭 장 분포SFD switching field distribution

[실시예 1]Example 1

버톨리드 산화철 안료(보자력 : 33.7kA/m, spec. 포화 자기화;90nTm3/g, 비표면적 : 27m2/g, 면비율 : 9 : 1, FeO함량 : 4.5%) 480g을 물 2.4ℓ에 분산시킨다. 증류수 500ml속의 FeSO4·7H2O 181g의 용액과 증류수 83ml 속의 CoSO4·7H2O 30.5g의 용액을 40℃에서 5l들이 교반 용기 속에 도입하면서 용액 속에 질소를 통과 시킨다. 수산화나트륨용액(740g NaOH/ℓ) 632ml의 증류수 218ml를 가한 후, 반응용액을 질소하에 80℃로 가열하고, 5시간 동안 공기를 사용하여 가스를 도입한다. 이후에 증류수 167ml속에 CoSO461g의 용액을 가하고, 반응용액을 95℃로 가열한 다음, 공기를 사용하여 추가로 16시간 동안 가스를 도입한다.Butolithic iron oxide pigments (magnetism: 33.7 kA / m, spec. Saturation magnetization; 90 nTm 3 / g, specific surface area: 27 m 2 / g, surface ratio: 9: 1, FeO content: 4.5%) 480 g in 2.4 L of water Disperse A solution of 181 g of FeSO 4 · 7H 2 O in 500 ml of distilled water and 30.5 g of CoSO 4 · 7H 2 O in 83 ml of distilled water was introduced into a stirring vessel at 40 ° C. while passing nitrogen through the solution. After adding 218 ml of 632 ml of sodium hydroxide solution (740 g NaOH / L) to distilled water, the reaction solution was heated to 80 ° C. under nitrogen, and gas was introduced using air for 5 hours. Thereafter, 61 g of CoSO 4 was added to 167 ml of distilled water, the reaction solution was heated to 95 ° C., and then gas was introduced for an additional 16 hours using air.

현탁액을 실험용 여과 압축기로 여과 및 세척하고 회전 공기 건조 챔버속에서 30℃에서 건조시켜 가공한다. 건조된 샘플을 밀도가 0.90g/ml로 되도록 압착한 다음, 상술한 바와 같이 자력 테입으로 가공한다.The suspension is filtered and washed with an experimental filtration compressor and processed by drying at 30 ° C. in a rotary air drying chamber. The dried sample is compressed to a density of 0.90 g / ml and then processed into magnetic tape as described above.

[비교실시예 1]Comparative Example 1

실시예 1에서 기술한 산화철 코어 물질 480g을 증류수 2.4ℓ에 분산시킨다. 이후에, 증류수 500ml속의 FeSO4·7H2272g의 용액과 물 250ml속의 CoSO4·7H2O 91.5g의 용액을 40℃에서 5ℓ들이 교반용기 속에 도입하면서 용액 속에 질소를 취입시킨다. 수산화나트륨용액(740g NaOH/ℓ) 842ml를 가한 후, 용액을 질소하에 80℃로 가열하고, 공기를 사용하여 6시간 동안 가스를 도입한다. 현탁액을 실시예 1에서 기술한 바와 같이 가공한다.480 g of the iron oxide core material described in Example 1 was dispersed in 2.4 L of distilled water. Thereafter, a solution of 272 g of FeSO 4 · 7H 2 in 500 ml of distilled water and 91.5 g of CoSO 4 · 7H 2 O in 250 ml of water was introduced at 40 ° C. into a 5 liter stirred container, and nitrogen was blown into the solution. After 842 ml of sodium hydroxide solution (740 g NaOH / L) was added, the solution was heated to 80 ° C. under nitrogen, and gas was introduced for 6 hours using air. The suspension is processed as described in Example 1.

[비교 실시예 2]Comparative Example 2

실시예 1에서 기술한 산화철 안료 480g을 물 2.4ℓ에 분산시키고, 증류수 500ml 속의 FeSO4·7H2O 181g의 용액을 40℃에서 5ℓ들이 교반 용기 속에 도입하면서 용액 속으로 질소를 취입한다. 수산화나트륨용액(740g NaOH/ℓ) 632ml와 증류수 218ml를 가한 후, 반응용액을 질소하에 80℃로 가열하고, 공기를 사용하여 5시간 동안 가스를 도입한다. 이후에, 증류수 250ml 속의 CoSO4·7H2O 91.5g의 용액을 가하고, 반응용액을 95c로 가열한 다음, 추가로 16시간 동안 가스를 도입한다.480 g of the iron oxide pigment described in Example 1 was dispersed in 2.4 L of water, and nitrogen was blown into the solution while introducing a solution of 181 g of FeSO 4 · 7H 2 O in 500 ml of distilled water into a 5 L stirring vessel at 40 ° C. After adding 632 ml of sodium hydroxide solution (740 g NaOH / L) and 218 ml of distilled water, the reaction solution was heated to 80 ° C. under nitrogen, and gas was introduced for 5 hours using air. Thereafter, a solution of 91.5 g of CoSO 4 · 7H 2 O in 250 ml of distilled water is added, the reaction solution is heated to 95c, and then gas is introduced for another 16 hours.

현탁액을 실시예 1에서 기술한 바와 같이 가공한다.The suspension is processed as described in Example 1.

[비교실시예 3]Comparative Example 3

실시예 1에서 기술한 산화철 안료 480g을 증류수 2.4ℓ에 분산시키고, 증류수 500ml 속의 FeSO4·7H2O 181g의 용액을 40℃에서 5ℓ들이 교반 용기에 도입하면서 용액 속으로 질소를 통과시킨다. 수산화나트륨용액(740g NaOH/ℓ) 632ml와 증류수 218ml를 가한 후, 반응용액을 질소하에 5분 동안 교반한다. 이후에 물 250ml 속의 CoSO4·7H2O 91.5g의 용액을 가하고, 반응용액을 80C로 가열하면서 질소를 통과시킨 후, 공기를 사용하여 6시간 동안 가스를 도입한다. 현탁액을 실시예 1에 기술한 바와 같이 가공한다.480 g of the iron oxide pigment described in Example 1 is dispersed in 2.4 L of distilled water, and a solution of 181 g of FeSO 4 · 7H 2 O in 500 ml of distilled water is introduced into a 5 L stirring vessel at 40 ° C., and nitrogen is passed through the solution. After adding 632 ml of sodium hydroxide solution (740 g NaOH / L) and 218 ml of distilled water, the reaction solution was stirred for 5 minutes under nitrogen. Thereafter, a solution of 91.5 g of CoSO 4 · 7H 2 O in 250 ml of water was added thereto, and the reaction solution was passed through nitrogen while heating to 80 C, followed by introducing gas for 6 hours using air. The suspension is processed as described in Example 1.

상기의 실시예에서 기술한 실험에 따르면, 양호한 스위칭 장 분포와 결합된 충분히 높은 보자력장의 세기는 오직 상술한 방법에 의해서만 얻을 수 있음을 알 수 있다. 100℃이상의 온도에서의 후-단련 또는 건조는 필수적인 것은 아니지만 배제할 필요는 없다.According to the experiment described in the above embodiment, it can be seen that the strength of the sufficiently high coercive field combined with the good switching field distribution can be obtained only by the above-described method. Post-annealing or drying at temperatures above 100 ° C. is not essential but need not be excluded.

[표 1]TABLE 1

Figure kpo00001
Figure kpo00001

Claims (14)

1단계에서, 조성이 FeOx(여기서, x는 1.33 내지 1.5이다)인 자성 산화철 코어 물질 입자를 예비 피복 물질인 코발트를 함유하는 버톨리드 물질 또는 조성이 CoxFeIII 1-xFe2 IIIO4(여기서, x는 0보다 크고 1보다 작거나 같다)인 물질로 피복시킨 다음, 2단계에서, 예비 피복된 입자를 코발트 화합물로 피복시킴을 포함하여 자성 산화철 안료를 제조하는 방법.In step 1, a magnetic iron oxide core material particle having a composition of FeOx (where x is 1.33 to 1.5) is a butoxide material containing cobalt as a precoating material or a composition having a composition of Co x Fe III 1-x Fe 2 III O 4 A method of making a magnetic iron oxide pigment, comprising coating a precoated particle with a cobalt compound, followed by coating with a material wherein x is greater than 0 and less than or equal to 1, in step 2. 제1항에 있어서, 예비 피목 물질이 Fe(III)의 함량이 0 내지 67%인 철(II,III)염 및 코발트염인 방법.The method according to claim 1, wherein the pre-stock material is an iron (II, III) salt and a cobalt salt having a content of Fe (III) 0 to 67%. 제2항에 있어서, 예비 피복 물질을 산화조건 또는 불활성 조건하에 코어에 피복시키는 방법.The method of claim 2 wherein the precoat material is coated on the core under oxidizing or inert conditions. 제3항에 있어서, 예비 피복 물질을 공기의 존재하에 산화 조건하에서 코어에 피복시키는 방법.The method of claim 3 wherein the precoat material is coated on the core under oxidizing conditions in the presence of air. 제1항에 있어서, 예비 피복 물질을 산화조건 또는 불활성 조건하에 코어에 피복시키는 방법.The method of claim 1 wherein the precoat material is coated on the core under oxidizing or inert conditions. 제5항에 있어서, 예비 피목 물질을 공기의 존재하에 산화 조건하에서 코어에 피복시키는 방법.6. The method of claim 5 wherein the pre-wood material is coated on the core under oxidizing conditions in the presence of air. 제1항에 있어서, 예비 피복 물질을 염기성 매질속에서 코어에 피복시키는 방법.The method of claim 1 wherein the precoat material is coated on the core in a basic medium. 제1항에 있어서, 코어 입자를 Fe(II) 이온을 함유하는 용액 속에서, 용액 속에 Fe(II)가 잔존하지 않을때까지 교반함으로써 예비 피복 물질을 코어에 피복시키는 방법.The method of claim 1, wherein the core particles are coated in the solution containing Fe (II) ions by stirring until no Fe (II) remains in the solution. 제1항에 있어서, 코발트 화합물이 Co(II)염인 방법.The method of claim 1 wherein the cobalt compound is a Co (II) salt. 제9항에 있어서, 코발트(II)염이 CoSO4·7H2O인 방법.The method of claim 9, wherein the cobalt (II) salt is CoSO 4 .7H 2 O. 제1항에 있어서, 두 피복 물질 층 속의 Co함량이 코어 물질을 기준으로 하여 0.5 내지 10중량%가 되기에 충분한 양으로 피복 물질을 사용하는 방법.The method of claim 1 wherein the coating material is used in an amount sufficient to bring the Co content in the two coating material layers from 0.5 to 10 weight percent based on the core material. 제1항에 있어서, 2단계의 피복을 염기성 매질 속에서 수행하는 방법.The method of claim 1 wherein the two steps of coating are carried out in a basic medium. 제12항에 있어서, 알칼리성 매질이 -OH 농도가 0.1 내지 10mol/ℓ인 수성 알칼리 금속 수산화물인 방법.13. The process of claim 12 wherein the alkaline medium is an aqueous alkali metal hydroxide having a -OH concentration of 0.1 to 10 mol / l. 제1항에 따르는 방법으로 제조한 자성 산화철 안료.Magnetic iron oxide pigment prepared by the method according to claim 1.
KR1019890019226A 1988-12-24 1989-12-22 Process for the preparation of magnetic iron oxides and the pigments obtained therefrom KR930004584B1 (en)

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