EP0063730A3 - Process for stabilising pyrophoric acicular ferromagnetic metal particles essentially consisting of iron - Google Patents

Process for stabilising pyrophoric acicular ferromagnetic metal particles essentially consisting of iron

Info

Publication number
EP0063730A3
EP0063730A3 EP82103010A EP82103010A EP0063730A3 EP 0063730 A3 EP0063730 A3 EP 0063730A3 EP 82103010 A EP82103010 A EP 82103010A EP 82103010 A EP82103010 A EP 82103010A EP 0063730 A3 EP0063730 A3 EP 0063730A3
Authority
EP
European Patent Office
Prior art keywords
pyrophoric
metal particles
stabilising
iron
ferromagnetic metal
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.)
Withdrawn
Application number
EP82103010A
Other languages
German (de)
French (fr)
Other versions
EP0063730A2 (en
Inventor
Helmut Dr. Jakusch
Werner Dr. Loeser
Eberhard Dr. Koester
Peter Dr. Rudolf
Werner Dr. Senkpiel
Werner Dr. Steck
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.)
BASF SE
Original Assignee
BASF SE
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 BASF SE filed Critical BASF SE
Publication of EP0063730A2 publication Critical patent/EP0063730A2/en
Publication of EP0063730A3 publication Critical patent/EP0063730A3/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10—Oxidising
    • C23C8/12—Oxidising using elemental oxygen or ozone
    • C23C8/14—Oxidising of ferrous surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/14—Treatment of metallic powder
    • B22F1/145—Chemical treatment, e.g. passivation or decarburisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/06—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H01F1/061—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder with a protective layer

Abstract

Die Erfindung betrifft ein Verfahren zur Stabilisierung von pyrophoren, im wesentlichen aus Eisen bestehenden nadelförmigen Metallteilchen durch Reaktion mit sauer­ stoffhaltigen Gasen in zwei Stufen, wobei in der ersten Stufe bei einer Temperatur zwischen 25 und 45 °C bis zu ¹/₃ der im Endzustand vorliegenden Passivierungsschicht und in einer daran anschließenden zweiten Stufe bei einer Tem­ peratur zwischen 50 und 70 °C der restliche Teil der Pas­ sivierungsschicht gebildet wird. The invention relates to a method for stabilization of pyrophoric, essentially iron acicular metal particles by reaction with acid gases containing substances in two stages, being in the first stage at a temperature between 25 and 45 ° C up to ¹ / ₃ the passivation layer present in the final state and in a subsequent second stage at a tem temperature between 50 and 70 ° C the rest of the pass sivierungsschicht is formed.

EP82103010A 1981-04-25 1982-04-08 Process for stabilising pyrophoric acicular ferromagnetic metal particles essentially consisting of iron Withdrawn EP0063730A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19813116489 DE3116489A1 (en) 1981-04-25 1981-04-25 METHOD FOR STABILIZING PYROPHORES, SUBSTANTIALLY IRON, FERROMAGNETIC, NEEDLE-SHAPED METAL PARTICLES
DE3116489 1981-04-25

Publications (2)

Publication Number Publication Date
EP0063730A2 EP0063730A2 (en) 1982-11-03
EP0063730A3 true EP0063730A3 (en) 1983-04-13

Family

ID=6130824

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82103010A Withdrawn EP0063730A3 (en) 1981-04-25 1982-04-08 Process for stabilising pyrophoric acicular ferromagnetic metal particles essentially consisting of iron

Country Status (4)

Country Link
US (1) US4420330A (en)
EP (1) EP0063730A3 (en)
JP (1) JPS57181301A (en)
DE (1) DE3116489A1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59110701A (en) * 1982-12-16 1984-06-26 Mitsui Toatsu Chem Inc Stabilization of reduced iron powder for magnetic recording
DE3330767A1 (en) * 1983-08-26 1985-03-14 Bayer Ag, 5090 Leverkusen HANDLING STABLES IN THE ESSENTIAL EXAMPLE OF IRON MAGNETIC PIGMENTS, METHOD FOR THEIR PRODUCTION AND THEIR USE
DE3422916A1 (en) * 1984-06-20 1986-01-02 Bayer Ag, 5090 Leverkusen ESSENTIALLY IRON MAGNETIC PIGMENTS, METHOD FOR THE PRODUCTION AND USE THEREOF
JPS63199801A (en) * 1987-02-12 1988-08-18 Chisso Corp Stabilization treatment device for ferromagnetic metal powder
JPH0620008B2 (en) * 1987-08-24 1994-03-16 チッソ株式会社 Method for producing ferromagnetic metal powder having oxide film
JP2739600B2 (en) * 1989-10-03 1998-04-15 富士写真フイルム株式会社 Method of processing ferromagnetic metal powder and method of manufacturing magnetic recording medium
DE4115426A1 (en) * 1991-05-10 1992-11-12 Basf Magnetics Gmbh METHOD FOR THE STABILIZATION OF NEEDLE-SHAPED, FERROMAGNETIC METAL POWDERS, CONSISTENTLY OF IRON
WO1993009900A1 (en) * 1991-11-22 1993-05-27 Ampex Media Corporation Storage of metal particles
US5849817A (en) * 1994-03-24 1998-12-15 Silberline Limited Metal pigments
GB2288411B (en) * 1994-03-24 1998-04-15 Silberline Ltd Metal pigments
JP2001305733A (en) * 2000-04-18 2001-11-02 Sumitomo Chem Co Ltd Method for preserving photosensitive composition
CN100463863C (en) * 2006-11-24 2009-02-25 金川集团有限公司 Method for preventing self-combustion of ultrafine carbonyl iron powder

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2046957A1 (en) * 1969-06-20 1971-03-12 Philips Nv
FR2090199A1 (en) * 1970-05-22 1972-01-14 Ampex
NL7018910A (en) * 1970-12-29 1972-07-03 Passivating ferromagnetic powder - by treating cooled moving powder with limited amount of oxygen at controlled temp and gradually
DE2524520A1 (en) * 1975-06-03 1976-12-16 Philips Patentverwaltung Stabilising pyrophoric iron powder - produced by reaction with gases contg. oxygen under press.

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3520676A (en) * 1968-05-28 1970-07-14 Eastman Kodak Co Stabilization of pyrophoric metal powder
US3767477A (en) * 1971-12-27 1973-10-23 Eastman Kodak Co Method for producing oxide coated iron powder of controlled resistance for electrostatic copying systems
DE2212934A1 (en) * 1972-03-17 1973-09-20 Philips Nv Iron powder prodn for magnetic recording - by redn of needle-like crystals of iron oxide or its hydrate in presence of
US3926617A (en) * 1973-02-21 1975-12-16 Midrex Corp Passivation of metallized pellets in bulk
US3967986A (en) * 1975-01-27 1976-07-06 U.S. Philips Corporation Method of preparing ferromagnetic material
DE2646348C2 (en) * 1976-10-14 1986-08-28 Basf Ag, 6700 Ludwigshafen Process for the production of acicular, ferromagnetic metal particles consisting essentially of iron and their use for the production of magnetic recording media
US4207092A (en) * 1977-03-03 1980-06-10 E. I. Du Pont De Nemours And Company Acicular α-iron particles, their preparation and recording media employing same
US4251592A (en) * 1979-04-03 1981-02-17 Toda Kogyo Corp. Stabilization treatment of acicular ferromagnetic iron or iron-alloy particles against the oxidation thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2046957A1 (en) * 1969-06-20 1971-03-12 Philips Nv
FR2090199A1 (en) * 1970-05-22 1972-01-14 Ampex
NL7018910A (en) * 1970-12-29 1972-07-03 Passivating ferromagnetic powder - by treating cooled moving powder with limited amount of oxygen at controlled temp and gradually
DE2524520A1 (en) * 1975-06-03 1976-12-16 Philips Patentverwaltung Stabilising pyrophoric iron powder - produced by reaction with gases contg. oxygen under press.

Also Published As

Publication number Publication date
US4420330A (en) 1983-12-13
EP0063730A2 (en) 1982-11-03
JPS57181301A (en) 1982-11-08
DE3116489A1 (en) 1982-11-11

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Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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AK Designated contracting states

Designated state(s): DE FR GB NL

PUAL Search report despatched

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17P Request for examination filed

Effective date: 19821211

AK Designated contracting states

Designated state(s): DE FR GB NL

STAA Information on the status of an ep patent application or granted ep patent

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18W Application withdrawn

Withdrawal date: 19840620

RIN1 Information on inventor provided before grant (corrected)

Inventor name: LOESER, WERNER, DR.

Inventor name: RUDOLF, PETER, DR.

Inventor name: STECK, WERNER, DR.

Inventor name: SENKPIEL, WERNER, DR.

Inventor name: KOESTER, EBERHARD, DR.

Inventor name: JAKUSCH, HELMUT, DR.