Patents by Inventor Manfred Ohlinger
Manfred Ohlinger has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 4344791Abstract: A process for the manufacture of acicular ferromagnetic iron particles by heating a goethite, provided with a shape-stabilizing surface coating, at 250.degree.-450.degree. C. in an atmosphere containing water vapor at a partial pressure of not less than 30 mbar, to give alpha-iron(III) oxide, and reducing this material with hydrogen at 275.degree.-425.degree. C., and the use of the iron particles thus obtained as magnetic material in the production of magnetic recording media.Type: GrantFiled: July 31, 1980Date of Patent: August 17, 1982Assignee: BASF AktiengesellschaftInventors: Werner Steck, Wilhelm Sarnecki, Laszlo Marosi, Manfred Ohlinger, Werner Loeser
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Patent number: 4340494Abstract: 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 m.sup.2 /g, and is added in a total amount of up to 0.5% by weight, based on the resulting chromium dioxide.Type: GrantFiled: October 21, 1980Date of Patent: July 20, 1982Assignee: BASF AktiengesellschaftInventors: Manfred Ohlinger, Guenter Vaeth, Norbert Mueller, Eugen Wettstein
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Patent number: 4295879Abstract: A process for the manufacture of acicular ferromagnetic iron particles by reducing an iron(III) oxide which carries a shape-stabilizing surface coating and has been produced by heating acicular iron(III) oxide hydroxide at 250.degree.-390.degree. C. in an atmosphere containing water vapor at a partial pressure of not less than 30 mbar, with hydrogen at 275.degree.-425.degree. C.Type: GrantFiled: July 31, 1980Date of Patent: October 20, 1981Assignee: BASF AktiengesellschaftInventors: Werner Steck, Wilhelm Sarnecki, Laszlo Marosi, Manfred Ohlinger, Horst Autzen
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Patent number: 4287233Abstract: 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.degree.-200.degree. C.Type: GrantFiled: January 29, 1980Date of Patent: September 1, 1981Assignee: BASF AktiengesellschaftInventors: Peter Rudolf, Werner Steck, Eberhard Koester, Manfred Ohlinger, Christof Jaeckh
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Patent number: 4275114Abstract: Chromium dioxide magnetic pigments are stabilized against loss of their magnetic properties by treating them, in aqueous and/or alcoholic suspension, with a block copolymer consisting of siloxane units and alkyleneoxy units of 2 to 4 carbon atoms, the alkyleneoxy units being bonded to the polysiloxane radical by a Si--O--C or Si--C group, in an amount of from 1 to 40% by weight based on the chromium dioxide, after which the latter is separated off and dried at from 50.degree. to 200.degree. C. The stabilized chromium dioxide magnetic pigments may be used for the manufacture of magnetic recording media exhibiting improved stability of the magnetic properties under adverse climatic conditions.Type: GrantFiled: March 10, 1977Date of Patent: June 23, 1981Assignee: BASF AktiengesellschaftInventors: Eduard Schoenafinger, Herbert Motz, Manfred Ohlinger, Paul Deigner, Werner Grau
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Patent number: 4271234Abstract: An iron oxide pigment having a coating of a silane of the formulaR.sub.n Si(OR').sub.4-nwhereinR is an, in some cases, branched or oxygen-bridge-containing alkyl or alkenyl moiety of 1 to 18 carbon atoms, or an aryl moiety,R' is an, in some cases, branched and, in some cases, oxygen-bridge-containing alkyl moiety of 1 to 8,n=1 to 3,or a hydrolysis product thereof; a magnetic tape containing such coated iron oxide pigment and a process for coating such iron oxide pigment. There is particularly disclosed the treatment of iron oxide magnetic pigments to thereby improve their wear resistance and dispersibility in organic mediums.Type: GrantFiled: January 31, 1979Date of Patent: June 2, 1981Assignee: Dynamit Nobel AktiengesellschaftInventors: Eduard Schonafinger, Paul Deigner, Manfred Ohlinger, Helmut Jakusch, Jurgen Amort, Heinz Nestler, Claus-Dietrich Seiler, Otto Ambros
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Patent number: 4243059Abstract: In order to determine the homogeneity of a magnetic dispersion, part of the dispersion is conducted through a measuring cell prior to its application to a base, the size, number and type of those regions of the magnetic dispersion which interfere with the homogeneity being determined with the aid of magnetic measurements. The measuring cell contains a magnetic head, a magnetic dispersion is made to flow in a stream of constant cross section past the air gap of the magnetic head, and a magnetic field at least partially penetrating the magnetic dispersion is produced. From the characteristics of the amplified output voltage of the magnetic head the various parameters of the inhomogeneities in the magnetic dispersion can then be ascertained.Type: GrantFiled: May 22, 1978Date of Patent: January 6, 1981Assignee: BASF AktiengesellschaftInventors: Fritz Hammon, Manfred Ohlinger, Job-Werner Hartmann
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Patent number: 4213959Abstract: A process for the manufacture of acicular ferrimagnetic iron oxide by dehydrating acicular iron(III) oxide hydroxides to give acicular iron(III) oxides, then reducing these iron(III) oxides at from 300.degree. to 650.degree. C. by means of an organic compound which decomposes in this temperature range, and oxidizing the reduced product with an oxygen-containing gas at from 200.degree. to 500.degree. C., wherein the acicular iron(III) oxide hydroxides employed consist of a mixture of goethite and lepidocrocite, containing at least 60% of the latter, and the dehydration is carried out at from 250.degree. to 700.degree. C.Type: GrantFiled: August 3, 1978Date of Patent: July 22, 1980Assignee: BASF AktiengesellschaftInventors: Rudolf Brodt, Helmut Jakusch, Eberhard Koester, Werner Loeser, Manfred Ohlinger, Wilhelm Sarnecki, Werner Steck
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Patent number: 4212903Abstract: The invention relates to a process for improving the magnetic properties, especially the remanent magnetization, of gamma-iron(III) oxide which can be used advantageously as the magnetic component in magnetic recording media exhibiting reduced print-through. For this purpose, a gamma-iron(III) oxide manufactured according to known processes is heated at temperatures of from 400.degree. to 700.degree. C., the magnetic pigment having basic compounds on the crystal surface during this heat treatment and retaining a pH value above 8 until heating is over. Gamma-iron(III) oxide magnetic pigments treated in this way are particularly suitable for the manufacture of low-noise magnetic recording media with high remanent magnetization and particularly low print-through.Type: GrantFiled: February 22, 1977Date of Patent: July 15, 1980Assignee: BASF AktiengesellschaftInventors: Georg Schnell, Fritz Hammon, Manfred Ohlinger
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Patent number: 4200678Abstract: A flexible multilayer magnetic recording medium exhibiting an improved signal-to-print-through ratio coupled with an improved maximum output level and diminished dc noise, comprising a non-magnetic base and, applied thereto, at least two superposed layers consisting of a binder with magnetizable particles uniformly dispersed therein, the upper magnetic layer containing a magnetic pigment giving a signal-to-print-through ratio of less than 55db and the lower magnetic layer(s) containing a magnetic pigment giving a signal-to-print-through ratio of 55 db or more.Type: GrantFiled: March 30, 1978Date of Patent: April 29, 1980Assignee: BASF AktiengesellschaftInventors: Philipp Pister, Franz Buettner, Fritz Hammon, Manfred Ohlinger, Heinz Stritzinger, Job-Werner Hartmann, Walter Schneider
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Patent number: 4188302Abstract: A process for the manufacture of an acicular magnetic iron oxide containing from 0.5 to 10 percent by weight of cobalt and up to 24 percent by weight of divalent iron, each based on the amount of iron(III) oxide, wherein an aqueous suspension of gamma-iron(III) oxide, containing cobalt(II) and iron(II) ions, the suspension having a hydroxyl ion concentration of more than 3.6.times.10.sup.-6 moles/liter, is heated at from 50.degree. to 100.degree. C. for at least 15 minutes, and the resulting precipitate is filtered off, washed until neutral, dried at below 100.degree. C. and thereafter heated at from 100.degree. to 200.degree. C.The products thus obtained give, even when their cobalt content is low, a very high coercive force, while the effect of temperature on the coercive force and residual induction is very slight.Type: GrantFiled: January 25, 1978Date of Patent: February 12, 1980Assignee: BASF AktiengesellschaftInventors: Hans-Juergen Becker, Christof Jaeckh, Eberhard Koester, Werner Loeser, Manfred Ohlinger, Werner Steck
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Patent number: 4178171Abstract: A process for the manufacture of acicular ferromagnetic iron particles by reducing acicular iron(III) oxide hydroxides which consist of pure synthetic lepidocrocite or a mixture of synthetic goethite and at least 70% by weight of synthetic lepidocrocite.The iron(III) oxide hydroxides used carry, on their surface, an alkaline earth metal cation and an anion of a monobasic, dibasic or tribasic aliphatic carboxylic acid of up to 6 carbon atoms or an organic compound containing at least two groups capable of chelating the alkaline earth metal cation, and are produced in such a way that they consist of at least 70 percent by weight of lepidocrocite and have a length-to-width ratio of not less than 15:1.Reduction of such iron(III) oxide hydroxides gives iron particles with pronounced shape anisotropy, which exhibit both good magnetic properties and a narrow field strength distribution.Type: GrantFiled: March 20, 1978Date of Patent: December 11, 1979Assignee: BASF AktiengesellschaftInventors: Werner Steck, Rudolf Brodt, Wilhelm Sarnecki, Helmut Jakusch, Manfred Ohlinger, Eberhard Koester
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Patent number: 4177317Abstract: Chromium dioxide magnetic pigments can be stabilized against the loss of their magnetic properties by treating them, in alcoholic aqueous suspension, with a silane or a hydrolysis product thereof, so that when the pigment is isolated from the suspension medium the particles bear at least partially hydrolyzed silane on their surfaces, and then drying the magnetic pigment at from 50.degree. to 200.degree. C.Type: GrantFiled: May 20, 1977Date of Patent: December 4, 1979Assignee: BASF AktiengesellschaftInventors: Eduard Schoenafinger, Paul Deigner, Eberhard Koester, Manfred Ohlinger, Dieter Schaefer, Werner Stumpfi, Juergen Amort, Claus-Dietrich Seiler, Heinz Nestler, Otto Ambros
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Patent number: 4169912Abstract: An iron oxide pigment having a coating of a silane of the formulaR.sub.n Si(OR').sub.4-nwhereinR is an, in some cases, branched or oxygen-bridge-containing alkyl or alkenyl moiety of 1 to 18 carbon atoms, or an aryl moiety,R' is an, in some cases, branched and, in some cases, oxygen-bridge-containing alkyl moiety of 1 to 8,N=1 to 3,Or a hydrolysis product thereof; a magnetic tape containing such coated iron oxide pigment and a process for coating such iron oxide pigment. There is particularly disclosed the treatment of iron oxide magnetic pigments to thereby improve their wear resistance and dispersibility in organic mediums.Type: GrantFiled: November 3, 1977Date of Patent: October 2, 1979Assignee: Dynamit Nobel AktiengesellschaftInventors: Eduard Schonafinger, Paul Deigner, Manfred Ohlinger, Helmut Jakusch, Jurgen Amort, Heinz Nestler, Claus-Dietrich Seiler, Otto Ambros
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Patent number: 4165232Abstract: A process for the manufacture of acicular ferromagnetic metal particles which essentially consist of iron and carry, on their surface, from 0.02 to 0.6% by weight of boron in the form of a borate, by reducing an acicular iron oxide with a gaseous reducing agent at from 250.degree. to 500.degree. C., wherein a compound selected from the group comprising boron oxyacids and their inorganic salts is precipitated on the said iron oxide before reduction.Type: GrantFiled: September 15, 1978Date of Patent: August 21, 1979Assignee: BASF AktiengesellschaftInventors: Christof Jaeckh, Werner Steck, Rudolf Brodt, Manfred Ohlinger, Werner Loeser, Eberhard Koester
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Patent number: 4155748Abstract: A method of preparing acicular ferromagnetic metal particles consisting essentially of iron and suitable for magnetic recording, said particles being modified at the surface with 0.02 to 0.2% by weight of carbon and with 0.5 to 1.9% by weight of phosphorus as phosphate, by reducing a finely divided acicular iron compound, wherein there are deposited on said iron compound, prior to reduction, (a) a hydrolysis-resistant substance selected from the group consisting of oxyacids of phosphorus, their esters and inorganic salts, and (b) a compound selected from the group consisting of aliphatic monobasic, dibasic and tribasic carboxylic acids of from 1 to 6 carbon atoms.Type: GrantFiled: September 29, 1977Date of Patent: May 22, 1979Assignee: BASF AktiengesellschaftInventors: Werner Steck, Hans H. Schneehage, Christof Jaeckh, Werner Huebner, Manfred Ohlinger, Werner Loeser
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Patent number: 4109046Abstract: Flexible multi-layer magnetic recording media comprising a non-magnetic flexible base and, applied thereto, two superposed magnetizable layers which contain a homogeneous mixture of acicular magnetic chromium dioxide in an organic binder.According to the invention, the magnetizable layer adjacent to the base contains a chromium dioxide having a specific surface area, measured by the BET method, of from 15 to 25 m.sup.2 /g, while the outer magnetic layer contains a chromium dioxide having a specific surface area, measured by the BET method, of from 26 to 35 m.sup.2 /g.Such magnetic recording media are distinguished by uniformly high sensitivity over the entire audible frequency range even if close manufacturing tolerances are not maintained.Type: GrantFiled: December 3, 1976Date of Patent: August 22, 1978Assignee: BASF AktiengesellschaftInventors: Fritz Hammon, Manfred Ohlinger, Horst Grosselfinger, Heinz Stritzinger, Job-Werner Hartmann, Eduard Schoenafinger, Walter Schneider
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Patent number: 4084936Abstract: In order to reduce corrosion of the inside walls of a reactor made of iron or an iron alloy and used for the synthesis of chromium dioxide by hydrothermal conversion of chromium(VI) oxide with chromium oxides of lower valency, lead or bismuth is added at those points of the reactor at which an aqueous phase occurs during conversion and which do not contact the chromium oxides to be converted. The lead or bismuth may be used in metallic form or in the form of their oxides, hydroxides or salts.Type: GrantFiled: July 6, 1976Date of Patent: April 18, 1978Assignee: BASF AktiengesellschaftInventors: Manfred Ohlinger, Gerhard Wagner, Gerhard Honecker, Heinz Stritzinger, Heinz Spaehn
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Patent number: 4061727Abstract: 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.Type: GrantFiled: October 15, 1976Date of Patent: December 6, 1977Assignee: BASF AktiengesellschaftInventors: Guenter Vaeth, Manfred Ohlinger, Heinz Stritzinger, Eduard Schoenafinger, Eugen Wettstein, Wolfgang Guth
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Patent number: 4061725Abstract: Acicular gamma-iron(III) oxide is manufactured by reacting an iron(II) salt solution with an aqueous solution of an alkali metal hydroxide and oxidizing the resulting suspension of iron(II) hydroxide in three stages. In a first stage, at most from 0.1 to 4% by weight of the amount of iron(II) hydroxide originally present is oxidized in the course of from 0.1 to 4 hours, in a second stage from 10 to 25% by weight of the said original amount are oxidized in the course of from 1.5 to 6 hours and in a third stage the remaining amount is oxidized. After the oxidation, the goethite formed is reduced to magnetite and the latter is then oxidized to acicular gamma-iron(III) oxide.Type: GrantFiled: October 15, 1976Date of Patent: December 6, 1977Assignee: BASF AktiengesellschaftInventors: Manfred Ohlinger, Eduard Schoenafinger, Walter Schneider, Heinz Stritzinger, Guenter Vaeth