An object of the present invention is to provide ferrite particles having high saturation magnetisation and electrical resistivity, excellent in dispersibility in a resin, a solvent, or a resin composition; a rein composition containing the ferrite particles; and a resin molding composed of the resin composition. A Ni-Zn-Cu ferrite particle is in a single crystalline body having an average particle diameter of 1 to 2000 nm, has a polyhedral particle shape, and comprises 5 to 10 wt % of Ni, 15 to 30 wt % of Zn, 1 to 5 wt % of Cu, and 25 to 50 wt % of Fe.

An object of the present invention is to provide ferrite particles having high saturation magnetisation and electrical resistivity, excellent in dispersibility in a resin, a solvent, or a resin composition; a rein composition containing the ferrite particles; and a resin molding composed of the resin composition. A Ni-Zn-Cu ferrite particle is in a single crystalline body having an average particle diameter of 1 to 2000 nm, has a polyhedral particle shape, and comprises 5 to 10 wt % of Ni, 15 to 30 wt % of Zn, 1 to 5 wt % of Cu, and 25 to 50 wt % of Fe.

The present invention provides a powdered ferrite having high dispersibility in a resin and high electromagnetic shielding characteristics. The powdered ferrite comprises platy ferrite particles having a spinel crystal structure. The powdered ferrite comprises at least 50 number % platy ferrite particles each having at least one protrusion on a surface of the particle, and the protrusion has a shape selected from the group consisting of a rectangular pyramid, a truncated rectangular pyramid, an elongated rectangular pyramid, and combinations thereof.

The present invention provides a powdered ferrite having high dispersibility in a resin and high electromagnetic shielding characteristics. The powdered ferrite comprises platy ferrite particles having a spinel crystal structure. The powdered ferrite comprises at least 50 number % platy ferrite particles each having at least one protrusion on a surface of the particle, and the protrusion has a shape selected from the group consisting of a rectangular pyramid, a truncated rectangular pyramid, an elongated rectangular pyramid, and combinations thereof.

An electromagnetic wave absorbing sheet is provided that can adequately absorb electromagnetic waves at high frequencies in and above the millimeter wave band, can have excellent flexibility, and can easily be placed in any desired portion.

The electromagnetic wave absorbing sheet includes an electromagnetic wave absorbing layer 1 containing a magnetic iron oxide 1a that magnetically resonates at frequencies in and above the millimeter wave band and a resin binder 1b. The electromagnetic wave absorbing sheet absorbs radiated electromagnetic waves by magnetic resonance of the magnetic iron oxide. The electromagnetic wave absorbing sheet has a flexibility evaluation value F (g/mm.sup.2) of more than 0 and 6 or less, which is determined by measuring an applied weight (g) that is required to bend a ribbon-like electromagnetic wave absorbing sheet in the elastic deformation region so that a distance d between the inner surfaces of the ribbon-like sheet at a position L spaced 10 mm from the bent portion of the ribbon-like sheet is 10 mm, and dividing the applied weight (g) by a cross-sectional area D (mm.sup.2) of the ribbon-like sheet.

A laminated substrate includes an upper prepreg cured body, a lower prepreg cured body and a magnetic member. The magnetic member is sandwiched between the upper prepreg cured body and the lower prepreg cured body in an up-down direction. The upper prepreg cured body is directly coupled to the lower prepreg cured body all over a predetermined area surrounding the magnetic member in a plane perpendicular to the up-down direction. The magnetic member is formed by binding soft magnetic metal powder using a binder. The soft magnetic metal powder consists of particles each of which has a flat shape. The binder comprises inorganic oxide as a chief ingredient. The magnetic member includes the soft magnetic metal powder of 60 vol. % or more and open pores of 10 vol. % or more and 30 vol. % or less. The magnetic member has a thickness of 0.3 mm or less.

An object of the present invention is to provide ferrite particles having a high saturation magnetisation, and being excellent in the dispersibility in a resin, a solvent or a resin composition, a resin composition including the ferrite particles, and a resin film composed of the resin composition. The ferrite particles are a single crystalline body having an average particle size of 1 to 2000 nm, and Mn-based ferrite particles having a spherical shape, and have a saturation magnetisation of 45 to 95 Am.sup.2/kg. The resin composition includes the ferrite particles as a filler. The resin film is composed of the resin composition.

An object of the present invention is to provide ferrite particles having a high saturation magnetisation, and being excellent in the dispersibility in a resin, a solvent or a resin composition, a resin composition including the ferrite particles, and a resin film composed of the resin composition. The ferrite particles are a single crystalline body having an average particle size of 1 to 2000 nm, and Mn-based ferrite particles having a spherical shape, and have a saturation magnetisation of 45 to 95 Am.sup.2/kg. The resin composition includes the ferrite particles as a filler. The resin film is composed of the resin composition.

Provided herein is a magnetic sheet. The magnetic sheet according to one embodiment of the present invention includes a magnetic layer formed of crushed pieces of a magnetic body to improve flexibility of the magnetic sheet, and a thin film coating layer formed on at least one surface of the magnetic layer to maintain the magnetic layer in a sheet shape and buffer an external force applied to the crushed pieces of the magnetic body. According to the present invention, since the magnetic sheet is improved in mechanical strength properties, such as a tensile property, a bending property, and the like, to have significantly superior flexibility, degradation of physical properties, such as magnetic permeability and the like, caused by physical damage such as unintended cracks in the magnetic body provided in the magnetic sheet can be prevented even in the process of storing, transferring, and attaching the magnetic sheet to a target object and during usage of an electronic device provided with the target object to which the magnetic sheet is attached, and the magnetic sheet can be attached to a target surface of the target object with a superior adhering force even when a stepped portion is present at the surface, and at the same time, the magnetic sheet can block the influence of a magnetic field on parts of a portable terminal device or a human body of a user using the portable terminal device, significantly increase transmission and reception efficiencies and distances of a data and/or wireless power signal, and maintain the above-described performance for a long period of time, such that the magnetic sheet can be widely used in various portable devices such as mobile devices, smart appliances, devices for the Internet of Things, and the like.

A noise reduction tool includes a magnetic body that can be wound around, more than one turn around an axis of an electric wire or an electric wire bundle, the electric wire or the electric wire bundle and a fixing member that fixes, to each other, overlapping sections of a stacked portion in the magnetic body having a winding shape wound around the electric wire or the electric wire bundle and fixes the magnetic body to the electric wire or the electric wire bundle while keeping the winding shape of the magnetic body. The magnetic body is capable of changing a winding diameter according to an electric wire diameter of the electric wire or an electric wire bundle diameter of the electric wire bundle, and the fixing member fixes, to each other, the overlapping sections corresponding to a winding diameter of the magnetic body irrespective of the winding diameter.