| Patent Number |
Title Of Patent |
Date Issued |
| 4451502 |
Method for manufacturing magnetic recording medium |
May 29, 1984 |
| A method for manufacturing a magnetic recording medium including the steps of applying a magnetic coating containing magnetic particles therein to a support, subjecting said support having the magnetic coating thereon to magnetic orientation treatment while the magnetic coating is still |
| 4363831 |
Process for producing magnetic powder having high coercive force |
December 14, 1982 |
| A magnetic iron oxide powder which has high coercive force and stable magnetic characteristics is produced by forming a surface layer of the magnetic iron oxide powder which comprises a cobalt compound as a main component. The magnetic iron oxide powder is treated with an aqueous sol |
| 4323464 |
Process for producing hydrated iron oxide having silicon and phosphorus component |
April 6, 1982 |
| A hydrated iron oxide comprising a silicon component and a phosphorus component is produced by adding a silicate and a phosphate in an aqueous solution of a base and mixing it with an aqueous solution of a ferrous if necessary with a small amount of zinc ion and oxidizing it under co |
| 4321302 |
Process for producing magnetic powder having high coercive force |
March 23, 1982 |
| A magnetic iron oxide powder having high coercive force is produced by dispersing a magnetic iron oxide comprising a silicon component and a phosphorus component in an aqueous solution of a cobalt ion and adding a base to the dispersion to be an alkaline condition and heat-treating the |
| 4311684 |
Process for producing iron oxide containing magnetite |
January 19, 1982 |
| In a process for producing an iron oxide having magnetite as a main component by heating to reduce a powder of an iron oxide or a hydrated iron oxide in an atmosphere for reduction, an improvement characterized in that said atmosphere for reduction comprises an inert gas, steam and a gas |
| 4305921 |
Process for producing iron oxide |
December 15, 1981 |
| In a process for producing an iron oxide having magnetite as a main component by heating to reduce a powder of an oxide or a hydrated iron oxide comprising an iron oxide as a main component in an atmosphere for reduction, an improvement characterized in that said atmosphere for reduc |
| 4302510 |
Magnetic recording medium |
November 24, 1981 |
| A magnetic recording medium having more than 550 Oersted of a coercive force, less than 1.8 of a ratio of a coercive force at -196.degree. C. to a coercive force at 25.degree. C., less than 1.0 wt. % of a content of Fe.sup.2+ is prepared by incorporating a magnetic powder obtained by |
| 4255409 |
Process for producing acicular goethite |
March 10, 1981 |
| An alkali hydroxide is added to an aqueous solution of ferrous salt to form a precipitate and a part of the solution is separated to control a ratio of an anion to a ferrous component to less than 1 and the ferrous component is oxidized to acicular goethite with an alkali metal chlorate |
| 4251504 |
Process for producing acicular goethite |
February 17, 1981 |
| An alkali hydroxide is added to an aqueous solution of ferrous salt to form a precipitate and a part of the solution is separated to control a ratio of an anion to a ferrous component to less than 1 and the ferrous component is oxidized to acicular goethite by bubbling air through the |
| 4112184 |
Magnetic recording medium and method of preparing |
September 5, 1978 |
| A magnetic recording medium is prepared by depositing magnetic particles of ferromagnetic, acicular iron oxide upon whose surface is adsorbed cobalt hydroxide, on a supporting substrate. |
| 4069367 |
Magnetic powder material comprising iron oxide particles with a copper-cobalt alloy coating |
January 17, 1978 |
| A powder magnetic material for use as a magnetic recording medium and a method of its manufacture are disclosed. More particularly, the disclosed powder magnetic material is adapted to provide a magnetic recording medium of low electric resistance. In particular, an alloy of cobalt and a |
| 4067755 |
Method of making powdered magnetic iron oxide material |
January 10, 1978 |
| A method of producing a powder magnetic material for use as a magnetic recording medium is disclosed. More particularly, the disclosed powder magnetic material is adapted to provide a magnetic recording medium of low electrical resistance. In particular, an alloy of cobalt and at least o |
| 4010310 |
Magnetic powder |
March 1, 1977 |
| An improved magnetic powder characterized by high coercive force and high magnetic flux density which is formed by admixing a cobalt compound with a magnetic iron oxide, and adding to said admixture a complex forming agent which complexes with the cobalt compound to promote adsorption of |
| 3977985 |
Magnetic recording medium comprising cobalt or cobalt alloy coated particles of spicular magneti |
August 31, 1976 |
| A magnetic recording medium is disclosed as comprising powdered magnetic particles upon which there is deposited a ferro-magnetic metal or alloy such as cobalt or a cobalt alloy. Each magnetic particle is a spiculate magnetite and the deposite of cobalt or a cobalt alloy is in the range |
| 3958068 |
Process for the production of powdered magnetic material |
May 18, 1976 |
| A process is disclosed for the production of powdered magnetic material for use in magnetic recording materials. The process comprises the steps of dispersing finely divided particles of a ferromagnetic oxide into an aqueous solution, dissolving therein salts of one or more ferromagnetic |
| 3953656 |
Magnetic recording medium and preparation thereof |
April 27, 1976 |
| The magnetic recording medium having a magnetic recording layer containing magnetic iron oxide having a cobalt content of 0.5 - 10 wt.% and a ratio of Fe.sup.2.sup.+ /Fe.sup.3.sup.+ of 0.1 - 0.35; wherein the half-value width of the differential curve of the residual magnetization curve |
