GB1437409A - Methods of making acicular goethite powder - Google Patents

Methods of making acicular goethite powder

Info

Publication number
GB1437409A
GB1437409A GB4504473A GB4504473A GB1437409A GB 1437409 A GB1437409 A GB 1437409A GB 4504473 A GB4504473 A GB 4504473A GB 4504473 A GB4504473 A GB 4504473A GB 1437409 A GB1437409 A GB 1437409A
Authority
GB
United Kingdom
Prior art keywords
powder
suspension
acicular
hydroxide
goethite powder
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.)
Expired
Application number
GB4504473A
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.)
Sony Corp
Original Assignee
Sony 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 Sony Corp filed Critical Sony Corp
Publication of GB1437409A publication Critical patent/GB1437409A/en
Expired 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
    • 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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
    • 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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Dermatology (AREA)
  • General Health & Medical Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Compounds Of Iron (AREA)

Abstract

1437409 Acicular goethite powder SONY CORP 26 Sept 1973 [30 Sept 1972] 45044/73 Heading C1A Acicular geothite powder, is made by (a) mixing an aqueous solution of alkali hydroxide with an aqueous solution of ferrous salt under an inert gaseous atmosphere to form a suspension of fsrric hydroxide, (b) continuously stirring the suspension under an inert gaseous atmosphere for 2 to 5 hours until a milk-white, colloidal, ferrous hydroxide suspension is formed, (c) oxidizing the suspension with an oxygen-containing gas and (d) recovering the goethite powder by separation and washing; all steps are carried out below the temperature at which ferric ion formation occurs. The goethite powder obtained may be converted to acicular maghemite powder (gamma-Fe 2 O 3 ) of high coercivity (e.g. 440-480 oersteds) by reducing with hydrogen, and then oxidizing with air at 250‹ C. Such acicular maghemite is suitable for use in making magnetic tapes.
GB4504473A 1972-09-30 1973-09-26 Methods of making acicular goethite powder Expired GB1437409A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47098511A JPS5221720B2 (en) 1972-09-30 1972-09-30

Publications (1)

Publication Number Publication Date
GB1437409A true GB1437409A (en) 1976-05-26

Family

ID=14221659

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4504473A Expired GB1437409A (en) 1972-09-30 1973-09-26 Methods of making acicular goethite powder

Country Status (4)

Country Link
JP (1) JPS5221720B2 (en)
CA (1) CA1064223A (en)
DE (1) DE2349112A1 (en)
GB (1) GB1437409A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53127400A (en) * 1977-04-13 1978-11-07 Nippon Telegr & Teleph Corp <Ntt> Production of goethite
JPS54110999A (en) * 1978-02-20 1979-08-30 Nippon Telegr & Teleph Corp <Ntt> Preparation of magnetic particulates
CH637212A5 (en) * 1980-04-29 1983-07-15 Schweizerische Beratungsstelle APPARATUS FOR ADJUSTING A SAFETY MOUNT MOUNTED ON A SKI.

Also Published As

Publication number Publication date
JPS4957397A (en) 1974-06-04
JPS5221720B2 (en) 1977-06-13
CA1064223A (en) 1979-10-16
DE2349112A1 (en) 1974-04-04

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee