Toda Kogyo Corporation

Sumitomo Electric Industries, Limited

Seiji Ishitani

Hiroko Morii

Kazuyuki Hayashi

Yasuyuki Tanaka

Toru Maeda

Haruhisa Toyoda

Naoto Igarashi

Hirokazu Kugai

Mamoru Kamigaki

Keisuke Iwasaki

A manufacturing method of a soft magnetic material has a step of preparing a metal magnetic particle containing iron as the main component, and a step of forming an insulating film surrounding the surface of the metal magnetic particle. The step of forming the insulating film includes a step of mixing and stirring the metal magnetic particle, aluminum alkoxide, silicon alkoxide, and phosphoric acid.

Manufacturing method of soft magnetic material and manufacturing method of dust core

A soft magnetic material is a soft magnetic material including a composite magnetic particle () having a metal magnetic particle () mainly composed of Fe and an insulating coating () covering metal magnetic particle (), and insulating coating () contains an iron phosphate compound and an aluminum phosphate compound. The atomic ratio of Fe contained in a contact surface of insulating coating () in contact with metal magnetic particle () is larger than the atomic ratio of Fe contained in the surface of insulating coating (). The atomic ratio of Al contained in the contact surface of insulating coating () in contact with metal magnetic particle () is smaller than the atomic ratio of Al contained in the surface of insulating coating (). Thus, iron loss can be reduced.

Soft magnetic material, powder magnetic core and method of manufacturing soft magnetic material

The soft magnetic material includes a plurality of composite magnetic particles having a metal magnetic particle and an insulating film surrounding the surface of the metal magnetic particle. The metal magnetic particle contains iron as the main component. The insulating film contains aluminum, silicon, phosphorus, and oxygen. The insulating film satisfies the relationship 0.4&#x2266;M/(M+M)&#x2266;0.9 and the relationship of 0.25&#x2266;(M+M)/M&#x2266;1.0 in the case that molar amount of aluminum contained in the insulating film is represented by M, the sum of the molar amount of aluminum contained in the insulating film and the molar amount of silicon contained in the insulating film is represented by (M+M), and the molar amount of phosphorus contained in the insulating film is represented by M.

Soft magnetic material comprising an insulating layer containing aluminum, silicon, phosphorous and oxygen; dust magnetic core; process for producing soft magnetic material; and process for producing dust magnetic core

Hematite particles aggregates as non-magnetic particles of the present invention are capable of forming a non-magnetic undercoat layer of a magnetic recording medium having a more excellent surface smoothness, which can exhibit not only an excellent dispersibility but also have an improving ability of a surface smoothness of a coating film produced therefrom by calendering treatment, a non-magnetic undercoat layer for magnetic recording medium which contains the hematite particles aggregates is exhibits a more excellent surface smoothness, and a magnetic recording medium having the non-magnetic undercoat layer, is exhibits a more excellent surface smoothness.

Hematite particles aggregates, non-magnetic undercoatt layer for magnetic recording medium using the same, and magnetic recording medium having the non-magnetic undercoat layer

A magnetic recording medium including a non-magnetic base film; and a magnetic recording layer formed on the non-magnetic base film. The magnetic recording layer contains a filler, a binder resin and surface-modified magnetic particles having an average particle diameter of 0.01 to 0.7 &mgr;m and contains magnetic particles and a silane monomer coat formed on surface of the magnetic particle by a dry-mixing method.

Magnetic recording medium

Black magnetic toner

Black magnetic toner and black magnetic composite particles therefor

A magnetic recording medium composed of a non-magnetic base film and a magnetic recording layer containing a binder resin, magnetic particles, and as a filler black composite hematite particles having an average diameter of 0.08 to 1.0 &mgr;m. The composite particles have cores of hematite particles which are surface coated with an organosilicon compound. A carbon black coating is formed on the organosilicon coating layer. In addition, the hematite core particles may have an oxide or hydroxide coating layer formed on the surface of the hematite core particle, between the organosilicon coating layer and the surface of the core particles. The magnetic recording medium has not only an excellent durability and a good electromagnetic performance, but also a low light transmittance, a small surface resistivity and an excellent surface smoothness.

Black magnetic composite particles for a black magnetic toner

Black magnetic composite particles for black magnetic toner and black magnetic toner using the same

Black non-magnetic composite particles for black toner according to the present invention, comprise:

Growing community of inventors

Hiroshima, Japan

Seiji Ishitani