GB1482157A - Cobalt acicular gamma ferric oxide - Google Patents

Cobalt acicular gamma ferric oxide

Info

Publication number
GB1482157A
GB1482157A GB43625/74A GB4362574A GB1482157A GB 1482157 A GB1482157 A GB 1482157A GB 43625/74 A GB43625/74 A GB 43625/74A GB 4362574 A GB4362574 A GB 4362574A GB 1482157 A GB1482157 A GB 1482157A
Authority
GB
United Kingdom
Prior art keywords
lepidocrocite
cobalt
modified
until
acicular
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
GB43625/74A
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.)
Pfizer Inc
Original Assignee
Pfizer Inc
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 Pfizer Inc filed Critical Pfizer Inc
Publication of GB1482157A publication Critical patent/GB1482157A/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
    • 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
    • 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
    • C01P2004/80—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
    • 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

1482157 Co-modified acicular Fe 2 O 3 PFIZER Inc 8 Oct 1974 [6 May 1974] 43625/74 Heading C1A An acicular γ-ferric oxide containing at least 0À25 atomic per cent of combined cobalt, (based on the iron content) which when incorporated with recording binder at a level of 75% by weight of the total formulation, provides a magnetic recording member having a magnetic stability coefficient of 4,000-10,000, is claimed per se. It may be prepared by (a) introducing an acqueous alkali solution into an aqueous ferrous chloride solution which contains 0À25- 0À7 pound FeCl 2 per gallon, the alkali solution being added at the rate of 0À03-0À2 equivalents per minute per mole of dissolved FeCl 2 whilst maintaining the temperature at 60-90‹ F., the addition proceeding until 20-85% of the dissolved iron has been added, (b) passing an oxygen containing gas into the aqueous mixture until the pH is between 2À6 and 4À1, (c) adding a water soluble cobaltous salt to the resulting lepidocrocite seed slurry in an amount equivalent to at least 0À25 atomic per cent cobalt based on the total iron introduced, (d) maintaining the slurry at 80-160‹ F. and a pH of 2À6-4À1 whilst simultaneously and continuously introducing an aqueous solution of alkali and an oxygen-containing gas until the iron content is completely precipitated as lepidocrocite, (e) continuing the process of step (d) until a pH of at least 7 is achieved so as to precipitate all of the cobalt on to the surface of the lepidocrocite and (f) reducing the co-modified lepidocrocite to co-modified Fe 3 O 4 at 650-800‹ F. and subsequently oxidizing to co-modified acicular γ-ferric oxide.
GB43625/74A 1974-05-06 1974-10-08 Cobalt acicular gamma ferric oxide Expired GB1482157A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US46745974A 1974-05-06 1974-05-06

Publications (1)

Publication Number Publication Date
GB1482157A true GB1482157A (en) 1977-08-10

Family

ID=23855785

Family Applications (1)

Application Number Title Priority Date Filing Date
GB43625/74A Expired GB1482157A (en) 1974-05-06 1974-10-08 Cobalt acicular gamma ferric oxide

Country Status (6)

Country Link
JP (1) JPS537320B2 (en)
CH (1) CH605414A5 (en)
DE (1) DE2520379C3 (en)
GB (1) GB1482157A (en)
NL (1) NL166244C (en)
SE (1) SE7505137L (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5942441B2 (en) * 1974-08-08 1984-10-15 富士写真フイルム株式会社 Manufacturing method of magnetic iron oxide
JPS5850005B2 (en) * 1974-08-20 1983-11-08 日立マクセル株式会社 Jikikirokuyouji Seifun Matsuno Seizouhou
DE2556406A1 (en) * 1975-12-15 1977-06-16 Bayer Ag PROCESS FOR THE CONTINUOUS PRODUCTION OF IRON OXIDE HYDROXIDE
DE2705967C2 (en) * 1977-02-12 1990-01-04 Basf Ag, 6700 Ludwigshafen Process for the production of acicular cobalt-containing magnetic iron oxide
DE2801395C2 (en) * 1978-01-13 1982-04-22 Bayer Ag, 5090 Leverkusen Thermally stabilized ferrimagnetic iron oxide
JPS5852806A (en) * 1981-09-24 1983-03-29 Hitachi Maxell Ltd Magnetic recording medium

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1226997B (en) * 1959-06-12 1966-10-20 Bayer Ag Process for the production of acicular, cobalt-containing gamma iron (III) oxide
US3573980A (en) * 1968-02-19 1971-04-06 Minnesota Mining & Mfg Method of making magnetic particles and recording tape
JPS4810994B1 (en) * 1969-07-26 1973-04-09
JPS4854497A (en) * 1971-11-10 1973-07-31

Also Published As

Publication number Publication date
CH605414A5 (en) 1978-09-29
SE7505137L (en) 1975-11-07
DE2520379A1 (en) 1975-11-13
JPS537320B2 (en) 1978-03-16
NL7505145A (en) 1975-11-10
DE2520379C3 (en) 1981-11-19
NL166244C (en) 1981-07-15
DE2520379B2 (en) 1980-09-25
JPS50154198A (en) 1975-12-11
NL166244B (en) 1981-02-16

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Legal Events

Date Code Title Description
PS Patent sealed
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee
728C Application made for restoration (sect. 28/1977)
728W Application withdrawn (sect. 28/1977)