# US 2014/0151595 A1 · Method of manufacturing hexagonal ferrite magnetic particles, method of manufacturing magnetic coating material, and method of manufacturing magnetic recording medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151595 A1 - Document ID: US20140151595A1 - Status: Published application - Kind: A1 - Application number: 14/093,884 - Filed: 2013-12-02 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: FUJIFILM Corporation - Applicants: FUJIFILM Corporation - Inventors: Yasushi HATTORI; Kazufumi OMURA - Web page: https://patentgrep.com/patent/US20140151595A1 ## CPC - G11B 5/70678: {Ferrites} - C01G 49/0036: {containing one alkaline earth metal, magnesium or lead} - H01F 1/11: in the form of particles {(for magnetic record carriers G11B5/70626)} - C01P 2002/76: by a space-group or by other symmetry indications - C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer - C01P 2006/42: Magnetic properties - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS ## Abstract The method of manufacturing hexagonal ferrite magnetic particles includes providing hexagonal ferrite magnetic particles by conducting calcination of particles comprising an iron salt and an alkaline earth metal salt to cause ferritization; and further includes preparing the particles comprising an iron salt and an alkaline earth metal salt by adhering a glass component, followed by the alkaline earth metal salt, to the iron salt; and conducting calcination of the particles prepared to form a calcined product in which hexagonal ferrite is detected as a principal component in X-ray diffraction analysis. ## Claims ### Claim 1 A method of manufacturing hexagonal ferrite magnetic particles, which comprises: providing hexagonal ferrite magnetic particles by conducting calcination of particles comprising an iron salt and an alkaline earth metal salt to cause ferritization; and further comprises: preparing the particles comprising an iron salt and an alkaline earth metal salt by adhering a glass component, followed by the alkaline earth metal salt, to the iron salt; and conducting calcination of the particles prepared to form a calcined product in which hexagonal ferrite is detected as a principal component in X-ray diffraction analysis. ### Claim 2 (depends on 1) The method of manufacturing hexagonal ferrite magnetic particles according to claim 1, wherein the glass component is a hydrolysate of a silicon compound. ### Claim 3 (depends on 2) The method of manufacturing hexagonal ferrite magnetic particles according to claim 2, wherein the silicon compound is an alkoxysilane. ### Claim 4 (depends on 1) The method of manufacturing hexagonal ferrite magnetic particles according to claim 1, which further comprises preparing the iron salt by a reverse micelle method. ### Claim 5 (depends on 1) The method of manufacturing hexagonal ferrite magnetic particles according to claim 1, which comprises admixing a precursor of the glass component with a solution comprising the iron salt to cause the glass component, in the form of a hydrolysate of the precursor, to adhere to the iron salt. ### Claim 6 (depends on 5) The method of manufacturing hexagonal ferrite magnetic particles according to claim 5, wherein the precursor is added in a quantity ranging from 0.05 to 0.4 mole percent per 1 mole of iron present in the solution. ### Claim 7 (depends on 1) The method of manufacturing hexagonal ferrite magnetic particles according to claim 1, which comprises admixing a precursor of the alkaline earth metal salt and an additional component for converting the precursor to the alkaline earth metal salt, with a solution comprising a product obtained by adhering the glass component to the iron salt, to adhere the alkaline earth metal salt to the product. ### Claim 8 (depends on 7) The method of manufacturing hexagonal ferrite magnetic particles according to claim 7, wherein ammonia water is added together with the precursor of the alkaline earth metal salt and the additional component. ### Claim 9 (depends on 3) The method of manufacturing hexagonal ferrite magnetic particles according to claim 3, which comprises admixing a precursor of the glass component with a solution comprising the iron salt to cause the glass component, in the form of a hydrolysate of the precursor, to adhere to the iron salt. ### Claim 10 (depends on 9) The method of manufacturing hexagonal ferrite magnetic particles according to claim 9, wherein the precursor is added in a quantity ranging from 0.05 to 0.4 mole percent per 1 mole of iron present in the solution. ### Claim 11 (depends on 3) The method of manufacturing hexagonal ferrite magnetic particles according to claim 3, which comprises admixing a precursor of the alkaline earth metal salt and an additional component for converting the precursor to the alkaline earth metal salt, with a solution comprising a product obtained by adhering the glass component to the iron salt, to adhere the alkaline earth metal salt to the product. ### Claim 12 (depends on 11) The method of manufacturing hexagonal ferrite magnetic particles according to claim 11, wherein ammonia water is added together with the precursor of the alkaline earth metal salt and the additional component. ### Claim 13 (depends on 1) The method of manufacturing hexagonal ferrite magnetic particles according to claim 1, wherein the iron salt is iron hydroxide and the alkaline earth metal salt is carbonate of an alkaline earth metal. ### Claim 14 (depends on 1) The method of manufacturing hexagonal ferrite magnetic particles according to claim 1, which further comprises removing the glass component from a surface of the calcined product. ### Claim 15 (depends on 14) The method of manufacturing hexagonal ferrite magnetic particles according to claim 14, wherein the glass component is removed by dissolution with an alkali. ### Claim 16 (depends on 1) A method of manufacturing a magnetic coating material, which comprises: preparing hexagonal ferrite magnetic particles by the method of manufacturing according to claim 1; washing with water the hexagonal ferrite magnetic particles that have been prepared; and during or after the washing with water, adding a compound having a functional group serving as an anionic group in an aqueous solution to an aqueous solution comprising the hexagonal ferrite magnetic particles and causing the compound to adhere to a surface of the hexagonal ferrite magnetic particles. ### Claim 17 (depends on 16) The method of manufacturing a magnetic coating material according to claim 16, which further comprises subjecting the aqueous solution comprising the hexagonal ferrite magnetic particles to which the compound is adhered to a solvent replacement treatment to replace a solvent with an organic solvent. ### Claim 18 (depends on 16) A method of manufacturing a magnetic recording medium comprising a magnetic layer containing ferromagnetic powder and a binder on a nonmagnetic support, which comprises: preparing a magnetic coating material by the method according to claim 16; and forming the magnetic layer with the magnetic coating material prepared. ### Claim 19 (canceled) ### Claim 20 (depends on 17) A method of manufacturing a magnetic recording medium comprising a magnetic layer containing ferromagnetic powder and a binder on a nonmagnetic support, which comprises: preparing a magnetic coating material by the method according to claim 17; and forming the magnetic layer with the magnetic coating material prepared.