公开(公告)号：DE3143870A1

公开(公告)日：1983-05-11

申请号：DE3143870

申请日：1981-11-05

Applicant: BASF AG

Inventor： SARNECKI WILHELM DIPL CHEM DR ,  KOVACS JENOE DIPL CHEM DR ,  LOESER WERNER DIPL ING DR ,  RUDOLF PETER DIPL CHEM DR ,  VAETH GUENTER

IPC: C01G49/02 ,  C01G49/06 ,  C01G49/08 ,  G11B5/706 ,  H01F1/11

Abstract: Acicular ferrimagnetic iron oxides are prepared by a process in which iron (III) oxide hydroxide consisting essentially of lepidocrocite is reduced at from 350 DEG to 600 DEG C. by means of an organic compound which is a synthetic polymer with a molecular weight of from 3,000 to 40,000 to give magnetite, which, if desired, is subsequently partially or completely oxidized with an oxygen-containing gas at from 200 DEG to 450 DEG C.

公开(公告)号：DE2904085A1

公开(公告)日：1980-08-14

申请号：DE2904085

申请日：1979-02-03

Applicant: BASF AG

Inventor： OHLINGER MANFRED DIPL CHEM DR ,  REICHERT HANS DIPL ING DR ,  VAETH GUENTER ,  FAULHABER FRIEDRICH RICHARD DI ,  WERTHER JOACHIM DIPL ING DR ,  AUTZEN HORST DIPL CHEM DR ,  RUDOLF PETER DIPL CHEM DR

IPC: C01G49/06 ,  C01G49/08 ,  G11B5/706 ,  H01F1/11

公开(公告)号：DE2749757A1

公开(公告)日：1979-05-10

申请号：DE2749757

申请日：1977-11-07

Applicant: BASF AG

Inventor： VAETH GUENTER ,  OHLINGER MANFRED DIPL CHEM DR ,  HARTMANN HANS-JOERG DIPL ING D ,  VELIC MILAN DIPL ING DR ,  MUENZNER WULF DIPL ING DR

IPC: G11B5/706 ,  G11B5/712 ,  G11B5/68 ,  C09C1/34

Abstract: Magnetic recording material has a non-magnetic substrate with a firmly adhering magnetic coating of acicular ferromagnetic CrO2 finely dispersed in an organic polymeric binder and additives. Before incorporation in the binder, the CrO2 is suspended in an aq. soln. of the Fe(II) salt and a reducing agent, the Fe)II) ions are pptd. on the CrO2 as Fe(OH)2 by addn. of water-soluble hydroxide or carbonate and this Fe(OH)2 is then converted to an oxide deposit contg. Fe(III) by treatment with a gaseous or water-miscible oxidant. The oxide deposit pref. consists of goethite and/or lepidocrocite or magnetite. The Fe oxide deposit improves the stability and mechanical properties of the CrO2 under unfavourable climatic conditions.

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

IPC: C01G49/02 ,  C01G49/06 ,  C21B15/00 ,  G01N21/89 ,  G11B5/706 ,  H01F1/11 ,  C09C1/24

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.

公开(公告)号：DE2550225A1

公开(公告)日：1977-05-18

申请号：DE2550225

申请日：1975-11-08

Applicant: BASF AG

Inventor： VAETH GUENTER ,  OHLINGER MANFRED DIPL CHEM DR ,  STRITZINGER HEINZ DIPL ING ,  SCHOENAFINGER EDUARD DIPL CHEM ,  WETTSTEIN EUGEN ,  GUTH WOLFGANG

IPC: C01G49/06 ,  G11B5/706 ,  H01F1/10 ,  H01F1/11 ,  C09C1/24

Abstract: Acicular gamma -iron(III) oxide is manufactured by reacting an iron(II) salt solution with aqueous solutions of alkali metal hydroxides and oxidizing the resulting suspension of iron(II) hyroxides in 3 stages. In the first stage not more than 8 percent by weight of the iron(II) hydroxide originally present is oxidized over a period of 0.5 to 4 hours, in the second stage from 25 to 55 percent by weight over a period of 1.5 to 6 hours and the remainder thereof in a third stage. Following this oxidation, the goethite formed is reduced to magnetite, which is then oxidized to acicular gamma -iron(III) oxide.

公开(公告)号：DE2442763A1

公开(公告)日：1976-03-25

申请号：DE2442763

申请日：1974-09-06

Applicant: BASF AG

Inventor： VAETH GUENTER ,  BACHMANN RUDOLF DIPL CHEM DR ,  HARTMANN HEINRICH DIPL CHEM DR ,  SPOOR HERBERT DIPL CHEM DR ,  LEHNER AUGUST ING GRAD

IPC: C08G18/10 ,  C08G18/66 ,  C08G18/76 ,  C14C11/00 ,  C08G18/65

Abstract: Thermoplastic, elastic polyurethanes which are soluble in ethers and/or ketones and have a high surface hardness and high modulus of elasticity are manufactured from a polyester-ol and/or a polyether-ol, a substituted or unsubstituted diisocyanato-diphenylmethane or diisocyanato-diphenylsulfone, an aliphatic, branched-chain diol of the formula HOCH2-CR1R2-CO2OH, in which R1 is alkyl and R2 is alkyl or hydrogen, and, optionally, a triol.

公开(公告)号：DE2428690A1

公开(公告)日：1976-01-02

申请号：DE2428690

申请日：1974-06-14

Applicant: BASF AG

Inventor： VAETH GUENTER ,  HARTMANN HANS-JOERG DIPL ING D ,  FALK ROLAND DIPL CHEM DR ,  UHL KARL DIPL ING DR ,  GUTERMANN WINFREID ,  MAYER DIETER DR

IPC: G11B5/71 ,  G11B5/72

Abstract: A laminated magnetogram carrier, esp. UTR tape, with a layer, based on finely-divided magnetic pigment dispersed in a binder and suitable for magnetic recording, on a non-magnetisable support, contains 0.2-4, pref. 0.4-2 wt%, w.r.t. the wt. of the magnetic pigment, of a mixt. of aliphatic 14-18C monocarboxylic acids with m.pt. 50-60, pref. 52-55 degrees C. The acids are pref. added to the dispersion before application to the support.

公开(公告)号：CA962139A

公开(公告)日：1975-02-04

申请号：CA156755

申请日：1972-11-15

Applicant: BASF AG

Inventor： HARTMANN HANS-JOERG ,  HARTMANN JOB-WERNER ,  FRISCHMANN HARALD ,  VAETH GUENTER

IPC: C09D5/23 ,  G11B5/702

Abstract: Magnetic recording media comprising a non-magnetic support and a magnetic layer based on a dispersion of finely divided magnetic pigment in a binder consisting of a mixture of a special soluble hydroxyl-free polyester urethane.

公开(公告)号：DE3263427D1

公开(公告)日：1985-06-05

申请号：DE3263427

申请日：1982-10-22

Applicant: BASF AG

Inventor： SARNECKI WILHELM DR ,  KOVACS JENOE DR ,  LOESER WERNER DR ,  RUDOLF PETER DR ,  VAETH GUENTER

IPC: C01G49/02 ,  C01G49/06 ,  C01G49/08 ,  G11B5/706 ,  H01F1/11

Abstract: Acicular ferrimagnetic iron oxides are prepared by a process in which iron (III) oxide hydroxide consisting essentially of lepidocrocite is reduced at from 350 DEG to 600 DEG C. by means of an organic compound which is a synthetic polymer with a molecular weight of from 3,000 to 40,000 to give magnetite, which, if desired, is subsequently partially or completely oxidized with an oxygen-containing gas at from 200 DEG to 450 DEG C.

公开(公告)号：DE3061361D1

公开(公告)日：1983-01-20

申请号：DE3061361

申请日：1980-10-16

Applicant: BASF AG

Inventor： OHLINGER MANFRED DR ,  VAETH GUENTER ,  MUELLER NORBERT DR ,  WETTSTEIN EUGEN

IPC: C01G37/00 ,  C01G37/027 ,  G11B5/62 ,  G11B5/706 ,  H01F1/11

Abstract: A process for the manufacture of ferromagnetic chromium dioxide modified with foreign elements, by reacting oxides of trivalent and hexavalent chromium under superatmospheric pressure at an elevated temperature in the presence of water and of antimony(III) oxide as modifier, with or without other modifiers in an amount not exceeding 15% by weight, wherein the antimony(III) oxide employed as modifier is, to the extent of more than one-third, present as the senarmontite cubic modification, has a specific surface area, measured by the BET method, of from 1.5 to 15 m2/g, and is added in a total amount of up to 0.5% by weight, based on the resulting chromium dioxide.