JPS5556018A - Production of ferromagnetic powder - Google Patents

Production of ferromagnetic powder

Info

Publication number
JPS5556018A
JPS5556018A JP12986678A JP12986678A JPS5556018A JP S5556018 A JPS5556018 A JP S5556018A JP 12986678 A JP12986678 A JP 12986678A JP 12986678 A JP12986678 A JP 12986678A JP S5556018 A JPS5556018 A JP S5556018A
Authority
JP
Japan
Prior art keywords
iron oxide
contg
powder
magnetic powder
dispersion
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
JP12986678A
Other languages
Japanese (ja)
Inventor
Junichi Hirata
Haruo Ando
Susumu Kitaoka
Toshinobu Sueyoshi
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.)
Maxell Ltd
Original Assignee
Hitachi Maxell Ltd
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 Hitachi Maxell Ltd filed Critical Hitachi Maxell Ltd
Priority to JP12986678A priority Critical patent/JPS5556018A/en
Publication of JPS5556018A publication Critical patent/JPS5556018A/en
Pending legal-status Critical Current

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  • Hard Magnetic Materials (AREA)
  • Compounds Of Iron (AREA)

Abstract

PURPOSE: To obtain ferromagnetic powder of high coercive force useful as the recording element of a magnetic recording medium by forming a cobalt-contg. iron oxide layer on iron oxide magnetic powder followed by heat treatment in an aq. alkali soln. without drying.
CONSTITUTION: A dispersion in prepared contg. iron oxide magnetic powder mainly consisting of γ-Fe2O3 powder and magnetic powder obtd. by partially reducing the Fe2O3 powder, a Co salt-contg. metal salt, and an alkali metal such as sodium hydroxide in an amt. of one equivalent or more to the amt. of the metal salt. This dispersion is held at a temp. below the b.p. and treated to form a cobalt-contg. iron oxide layer on the iron oxide magnetic powder. The resulting cobalt-contg. iron oxide magnetic powder is well washed with water, filtered, immediately dispersed in an aq. alkali soln. without drying, and heat treated to raise the coercive force. The heat treatment temp. is 25°C or above, pref. at a temp. around the b.p. of the dispersion to be treated.
COPYRIGHT: (C)1980,JPO&Japio
JP12986678A 1978-10-20 1978-10-20 Production of ferromagnetic powder Pending JPS5556018A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12986678A JPS5556018A (en) 1978-10-20 1978-10-20 Production of ferromagnetic powder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12986678A JPS5556018A (en) 1978-10-20 1978-10-20 Production of ferromagnetic powder

Publications (1)

Publication Number Publication Date
JPS5556018A true JPS5556018A (en) 1980-04-24

Family

ID=15020214

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12986678A Pending JPS5556018A (en) 1978-10-20 1978-10-20 Production of ferromagnetic powder

Country Status (1)

Country Link
JP (1) JPS5556018A (en)

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