JPS5659630A - Manufacture of high coercive force magnetic powder - Google Patents

Manufacture of high coercive force magnetic powder

Info

Publication number
JPS5659630A
JPS5659630A JP13184079A JP13184079A JPS5659630A JP S5659630 A JPS5659630 A JP S5659630A JP 13184079 A JP13184079 A JP 13184079A JP 13184079 A JP13184079 A JP 13184079A JP S5659630 A JPS5659630 A JP S5659630A
Authority
JP
Japan
Prior art keywords
coercive force
iron oxide
oxide powder
state
ferromagnetic iron
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.)
Pending
Application number
JP13184079A
Other languages
Japanese (ja)
Inventor
Kazuo Takada
Shinji Umeki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TDK Corp
Original Assignee
TDK Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by TDK Corp filed Critical TDK Corp
Priority to JP13184079A priority Critical patent/JPS5659630A/en
Priority to NL8005605A priority patent/NL8005605A/en
Priority to GB8033229A priority patent/GB2060592A/en
Priority to DE19803038989 priority patent/DE3038989A1/en
Publication of JPS5659630A publication Critical patent/JPS5659630A/en
Pending legal-status Critical Current

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
    • G11B5/70657—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 with a skin
    • 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
    • G11B5/70647—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 with a skin
    • 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

Abstract

PURPOSE: To manufacture high coercive force magnetic powder with improved coercive force by dispersing ferromagnetic iron oxide powder in water at a weakly alkaline state, adding a Co ion-contg. aqueous soln. to the dispersion, and heating them after adjusting to a specified pH.
CONSTITUTION: In a method of manufacturing magnetically stable high coercive force magnetic iron oxide powder by forming a Co-base compound on the surface layer of ferromagnetic iron oxide powder, the ferromagnetic iron oxide powder is dispersed in water at a weakly alkaline pH state such as 8pH. To this dispersion is added a Co ion-contg. aqueous soln., and they are heated after adjusting to ≥12pH with an aqueous weak alkali soln. When the ferromagnetic iron oxide powder is dispersed in water, it is required to disperse the powder at a weakly alkaline pH state, and the purpose of this method is not attained at the acidic pH side. An alkaline state up to about 11 pH has the effect of enhancing the coercive force, yet the coercive force begins to lower at ≥about 11pH, resulting in a reverse effect.
COPYRIGHT: (C)1981,JPO&Japio
JP13184079A 1979-10-15 1979-10-15 Manufacture of high coercive force magnetic powder Pending JPS5659630A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP13184079A JPS5659630A (en) 1979-10-15 1979-10-15 Manufacture of high coercive force magnetic powder
NL8005605A NL8005605A (en) 1979-10-15 1980-10-10 METHOD FOR PREPARING MAGNETIC POWDER-IRON OXIDE.
GB8033229A GB2060592A (en) 1979-10-15 1980-10-15 Process for producing magnetic powder of high coercive force
DE19803038989 DE3038989A1 (en) 1979-10-15 1980-10-15 METHOD FOR PRODUCING MAGNETIC POWDER WITH HIGH COCERIVE FORCE

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13184079A JPS5659630A (en) 1979-10-15 1979-10-15 Manufacture of high coercive force magnetic powder

Publications (1)

Publication Number Publication Date
JPS5659630A true JPS5659630A (en) 1981-05-23

Family

ID=15067321

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13184079A Pending JPS5659630A (en) 1979-10-15 1979-10-15 Manufacture of high coercive force magnetic powder

Country Status (4)

Country Link
JP (1) JPS5659630A (en)
DE (1) DE3038989A1 (en)
GB (1) GB2060592A (en)
NL (1) NL8005605A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0076462B2 (en) * 1981-10-01 1991-01-16 Agency Of Industrial Science And Technology Method of production of magnetic particles
DE3631194A1 (en) * 1986-09-13 1988-03-24 Bayer Ag MAGNETIC IRON OXIDE PIGMENTS AND METHOD FOR THE PRODUCTION THEREOF
DE3631193A1 (en) * 1986-09-13 1988-03-24 Bayer Ag MAGNETIC IRON OXIDE PIGMENTS AND METHOD FOR THE PRODUCTION THEREOF

Also Published As

Publication number Publication date
NL8005605A (en) 1981-04-21
DE3038989A1 (en) 1981-04-23
GB2060592A (en) 1981-05-07

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