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公开(公告)号：DE2805621A1
公开(公告)日：1979-08-23
申请号：DE2805621
申请日：1978-02-10
Applicant: BASF AG
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公开(公告)号：DE2743298A1
公开(公告)日：1979-04-05
申请号：DE2743298
申请日：1977-09-27
Applicant: BASF AG
Inventor： JAECKH CHRISTOPHER DIPL CHEM D , STECK WERNER DIPL CHEM DR , BRODT RUDOLF DIPL CHEM DR , OHLINGER MANFRED DIPL CHEM DR , LOESER WERNER DIPL ING DR , KOESTER EBERHARD DIPL PHYS DR
Abstract: Acicular ferromagnetic metal particles essentially contain iron and carry, on their surface, from 0.02 to 0.6% by weight of boron in the form of a borate. Such particles may be obtained by reducing an acicular iron oxide with a gaseous reducing agent at from 250 to 500 DEG C, if boron oxyacid or an inorganic salt thereof is deposited on the said iron oxide before reduction. The acicular, ferromagnetic particles are principally used in magnetic recording media and the invention seeks to overcome the difficulty of providing such particles distinguished by a narrow particle size spectrum and pronounced acicular shape.
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公开(公告)号：DE2550308A1
公开(公告)日：1977-05-18
申请号：DE2550308
申请日：1975-11-08
Applicant: BASF AG
Inventor： OHLINGER MANFRED DIPL CHEM DR , SCHOENAFINGER EDUARD DIPL CHEM , VAETH GUENTER , STRITZINGER HEINZ DIPL ING , KOESTER EBERHARD DIPL PHYS DR , SCHNEEHAGE HANS HENNING DIPL C , STECK WERNER DIPL CHEM DR
Abstract: Goethite is obtained by reacting an aqueous solution of an iron (II) salt with an aqueous solution of an alkali metal hydroxide and oxidizing the resulting iron(II) hydroxide. The oxidation is carried out in three stages. In the first stage, from 4 to 15% by weight are oxidized in the course of from 0.4 to 5 hours, in the second stage from 60 to 85% by weight are oxidized in the course of from 1.5 to 6 hours and in a third stage the remaining amount of iron is oxidized.
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公开(公告)号：DE3116489A1
公开(公告)日：1982-11-11
申请号：DE3116489
申请日：1981-04-25
Applicant: BASF AG
Inventor： JAKUSCH HELMUT DIPL PHYS DR , LOESER WERNER DIPL ING DR , KOESTER EBERHARD DIPL PHYS DR , RUDOLF PETER DIPL CHEM DR , SENKPIEL WERNER DIPL CHEM DR , STECK WERNER DIPL CHEM DR
Abstract: A process for stabilizing pyrophoric acicular metal particles consisting essentially of iron, by reaction with oxygen-containing gases in two stages, wherein, in the first stage, up to 1/3 of the passivating layer present in the final state is formed at from 25 DEG to 45 DEG C. and, in a subsequent second stage, the remainder of the passivating layer is formed at from 50 DEG to 70 DEG C.
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公开(公告)号：DE2905352A1
公开(公告)日：1980-08-21
申请号：DE2905352
申请日：1979-02-13
Applicant: BASF AG
Inventor： RUDOLF PETER DIPL CHEM DR , STECK WERNER DIPL CHEM DR , KOESTER EBERHARD DIPL PHYS DR , OHLINGER MANFRED DIPL CHEM DR , JAECKH CHRISTOF DIPL CHEM DR
Abstract: A process for the manufacture of acicular magnetic iron oxide consisting of core of gamma-iron(III) oxide and a ferrite shell which contains, based on the total amount of magnetic material, from 0.2 to 12 per cent by weight of cobalt(II) ions and from 0.1 to 15 per cent by weight of iron(II) ions, wherein a precipitate of cobalt(II) hydroxide and iron (II) hydroxide is applied to acicular gamma-iron(III) oxide particles and the latter are heated at 100 DEG -200 DEG C.
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Patent Agency Ranking
公开(公告)号：DE2805405A1
公开(公告)日：1979-08-16
申请号：DE2805405
申请日：1978-02-09
Applicant: BASF AG
Inventor： AUTZEN HORST DIPL CHEM DR , MOTZ HERBERT DIPL ING DR , RUDOLF PETER DIPL CHEM DR , SARNECKI WILHELM DIPL CHEM DR , STECK WERNER DIPL CHEM DR , VAETH GUENTER
Abstract: A process for the manufacture of acicular ferrimagnetic iron oxide by converting acicular iron(III) oxide hydroxide at from 300 DEG to 650 DEG C., by treatment with an organic compound which decomposes in this temperature range in the presence of iron oxide, the iron(III) oxide hydroxide used for the reaction being a lepidocrocite which has been heat-treated at from 300 DEG to 700 DEG C.
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公开(公告)号：DE2608022A1
公开(公告)日：1977-09-08
申请号：DE2608022
申请日：1976-02-27
Applicant: BASF AG
Inventor： STECK WERNER DIPL CHEM DR , LOESER WERNER DIPL ING DR , STEUERWALD MANFRED , WUNSCH GERD DIPL CHEM DR , DEIGNER PAUL DR
Abstract: A process for the manufacture of wear-resistant magnetic recording media comprising a dimensionally stable base, a thin ferromagnetic metal layer, containing cobalt and/or nickel, firmly bonded thereto and a thin protective layer applied thereon. The protective layer is produced by treating the recording medium in a liquid basic medium, containing gaseous oxygen, for from 1 to 60 minutes at from 5 DEG to 70 DEG C., washing and drying the treated recording medium and then heating it in air at from 170 DEG to 300 DEG C. This method offers a particularly simple way of providing the ferromagnetic layer of the recording medium with a thin but uniform, mechanically stable and wear-resistant protective layer.
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公开(公告)号：DE2451232A1
公开(公告)日：1976-05-06
申请号：DE2451232
申请日：1974-10-29
Applicant: BASF AG
Inventor： WUNSCH GERD DIPL CHEM DR , FEHRENBACH HUBERT ING GRAD , LOESER WERNER DIPL ING DR , HUEBNER WERNER DIPL ING , FELLEISEN PETER DIPL ING , STECK WERNER DIPL CHEM DR
Abstract: In the prodn. of rigid magnetic recording supports by depositing a thin Co-contg. ferro-magnetic metal film (I) on an anodised Al disc as substrate, opt. after depositing a non-magnetic intermediate metal coating (II), and providing the surface of (I) with a thin protective coating (III), the anodised Al disc is activated by treatment with a soln. of Pd(O) complex in an organic solvent and the complex is decomposed, pref. by heating, then (I) is deposited by electroless and then opt. electro-plating. Activation eliminates the need for (II) and discs with very good electromagnetic and the mechanical properties in use and good corrosion resistance are obtd. (I) is deposited directly on the activated surface. The metal-coatd disc is tempered under an inert gas at 150-300 degrees C. (III) is applied using a soln. of a film-forming organic lacquer binder in a volatile solvent to give a dry unbaked film thickness of max. 0.3 mu m, then the coating is dried and baked in an O2-contg. atmos. for 1-15 h at 200-300 degrees C.
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公开(公告)号：DE2365178A1
公开(公告)日：1975-07-10
申请号：DE2365178
申请日：1973-12-29
Applicant: BASF AG
Inventor： KOESTER EBERHARD DIPL PHYS DR , WUNSCH GERD DIPL CHEM DR , DEIGNER PAUL DR , UHL KARL DIPL ING DR , STUMPFI WERNER DIPL PHYS DR , STECK WERNER DIPL CHEM DR
Abstract: 1496890 Surface oxidized magnetic powder BASF AG 30 Dec 1974 [29 Dec 1973] 56002/74 Heading C7U A particulate composition comprising Co 0À05 -0À96 Ni 0À95-0À04 is surface oxidized by N 2 O (optionally diluted with N 2 , CO 2 or noble gas) to form antiferromagnetic Co Ni oxide phase magnetically coupled with the ferromagnetic alloy phase. The particulate alloy may contain such amounts of Al, Cr, Fe, Mn and Zn that the magnetic exchange is not completely prevented and the treatment temperature may be up to 450‹C.
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公开(公告)号：DE2916403A1
公开(公告)日：1980-11-06
申请号：DE2916403
申请日：1979-04-23
Applicant: BASF AG
Inventor： RUDOLF PETER DIPL CHEM DR , STECK WERNER DIPL CHEM DR , SARNECKI WILHELM DIPL CHEM DR , JAECKH CHRISTOF DIPL CHEM DR
IPC: C01G49/00 , C01G49/02 , C09D5/23 , C09D7/12 , G11B5/70 , G11B5/706 , H01F1/11 , H01F1/36 , G11B5/62 , H01F1/00
Abstract: A process for the manufacture of acicular magnetic iron oxides which consist of a core of gamma-iron(III) oxide and a shell of a magnetite modified with zinc(II) ions and/or manganese(II) ions and which contain, based on the total modified gamma-iron(III) oxide, from 0.1 to 20 percent by weight of iron(II) ions, from 0.1 to 10 percent by weight of zinc(II) ions and/or from 0.1 to 10 percent by weight of manganese(II) ions.
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