Fuji Photo Film Company, Limited

Fujifilm Corporation

Koukichi Waki

Yasushi Hattori

Yasunori Ichikawa

Fumiko Shiraishi

Seiji Sugiyama

Keizo Ogawa

Yoshihisa Usami

Hiroyuki Hirai

Takashi Ozawa

Shigeharu Urabe

Kouichi Masaki

Genichi Furusawa

Shingo Ishimaru

Tomohide Ueyama

The producing unit for continuously producing metal microparticles formed of a multicomponent alloy accompanied by the generation of a byproduct gas through an early reaction of the formation of the metal particles comprises a first mixing unit for continuously supplying and mixing a plurality of solutions for conducting the early reaction, a second mixing unit for continuously supplying another solution to the reaction liquid containing the metal microparticles formed in the early reaction and for mixing the two solutions, to introduce dissimilar metal atoms into the crystal lattices of the metal microparticles, and a gas-liquid separation unit that is installed in a midway of the pipe which is made so as to have enough length to finish the early reaction, and which continuously passes the reaction liquid to the second mixing unit from the first mixing unit, and that continuously removes the byproduct gas generated with the proceeding of the early reaction.

Method and unit for continuously producing metal microparticle

The solution I is spouted from a first nozzle into a mixing chamber as a high-pressure jet stream of not less than 1 MPa and as a turbulent flow having a Reynolds number of not less than 10000 during the flow into the mixing chamber, and the solution II having a lower pressure than the solution I is spouted from a second nozzle into the mixing chamber as an orthogonal flow which intersects the solution I almost at right angles. The two solutions are mixed together and caused to react with each other, with the result that a mixed reaction solution Z containing alloy particles Z is formed.

Method of manufacturing magnetic particle, magnetic particle and magnetic recording medium

In a method of producing magnetic particles which includes the steps of preparing alloy particles capable of forming a CuAu or CuAu hard magnetic ordered alloy phase and of forming magnetic particles for forming CuAu or CuAu magnetic particles, a plurality of solutions Land Lfor preparing the alloy particles are passed in a thin-plate laminar flow and diffused in the direction perpendicular to the flow direction at the contact interface of the solutions Land Lin a mixing channel by using a microreactor, whereby a uniform mixing reaction is conducted in a short time.

Method of producing magnetic particles and reaction method using microreactor and microreactor

Ferromagnetic nanoparticles which are produced by reducing, in the presence of a polymer, two or more metals having different reduction potentials twice or more, using two or more reducing agents having different reduction potentials, a material coated with a dispersion of ferromagnetic nanoparticles in which the ferromagnetic nanoparticles are dispersed, and a magnetic recording medium which has a magnetic layer consisting of the material. The ferromagnetic nanoparticles having a holding power Hc of 95.5 kA/m or more, the material coated with the dispersion of ferromagnetic nanoparticles having excellent industrial coatability, and the magnetic recording medium using the dispersion are provided.

Ferromagnetic nanoparticles, material coated with dispersion of ferromagnetic nanoparticles, and magnetic recording medium using the material

When a reaction liquid is passed through a gas-liquid separation pipe having a larger volume per unit length than the volume per unit length of a pipe, a headspace part into which gas can be released is formed above the gas-liquid separation pipe, and the byproduct gas generated by the reaction changes into bubbles, moves upward in the reaction liquid, and is continuously released from a gas-liquid interface into the headspace part. While the gas is removed in the gas-liquid separation pipe, the pressure of the headspace part is controlled so as to be constant by a pressure adjustment device.

Gas-liquid separation method and unit

Disclosed are alloy nano-particles having a fluctuation coefficient of particle size of 20% or less and a fluctuation coefficient of composition of 20% or less. The alloy nano-particles have a low transformation point and hardly aggregate and which can form a flat magnetic film having high coercive force.

Alloy nano-particles

The present invention relates to a method of producing a magnetic particle including forming a layer containing an alloy particle that can form CuAu type or CuAu type hard magnetic order alloy phase on a support, oxidizing the layer, and annealing the layer in non-oxidizing atmosphere. The invention also relates to a method of producing a magnetic particle including producing an alloy particle that can form hard magnetic order alloy phase, oxidizing the alloy particle, and annealing the particle in non-oxidizing atmosphere, and a magnetic particle produced by the foregoing production method. Further, the invention relates to a magnetic recording medium comprising a magnetic layer containing a magnetic particle and a method of producing a magnetic recording medium including forming a layer containing an alloy that can form the foregoing hard magnetic order alloy phase, oxidizing the layer, and annealing the layer in non-oxidizing atmosphere.

Magnetic particle, its production method, magnetic recording medium and its production method

The present invention relates to a method of producing a magnetic particle including forming a layer containing an alloy particle that can form a CuAu-type or CuAu-type hard magnetic ordered alloy phase on a support, oxidizing the layer, and annealing the layer in a non-oxidizing atmosphere. The invention also relates to a method of producing a magnetic particle including producing an alloy particle that can form a hard magnetic ordered alloy phase, oxidizing the alloy particle, and annealing the particle in a non-oxidizing atmosphere, and a magnetic particle produced by the foregoing production method. Further, the invention relates to a magnetic recording medium comprising a magnetic layer containing a magnetic particle and a method of producing a magnetic recording medium including forming a layer containing an alloy that can form the foregoing hard magnetic ordered alloy phase, oxidizing the layer, and annealing the layer in a non-oxidizing atmosphere.

The present invention provides a magnetic recording medium comprising a support and a magnetic layer comprising a CuAu type or CuAu type magnetically hard ordered alloy phase, wherein a center line average roughness of a magnetic layer surface is 0.1 to 5 nm at a cut-off value of 0.25 mm, and a magnetic recording medium comprising a support and a magnetic layer containing, in a nonmagnetic metal oxide matrix, metal nanoparticles having a CuAu type or CuAu type magnetically hard ordered alloy phase.

Magnetic recording medium

The present invention relates to a magnetic recording medium comprising a magnetic layer on at least one side of a nonmagnetic substrate, the magnetic layer containing magnetic particles of a CuAu type or CuAu type ferromagnetic ordered phase, wherein a conductive layer is provided on at least one side of the nonmagnetic substrate.

Magnetic particle of CuAu(1) or CuAu(III) type its production method, magnetic recording medium and its production method

A method of producing a nanoparticle, the method comprising: a reducing step of adding an reverse micelle solution (II) obtained by mixing a water-insoluble organic solvent containing a surfactant with an aqueous metal salt solution to an reverse micelle solution (I) obtained by mixing a water-insoluble organic solvent containing a surfactant with an aqueous reducing agent solution, to carry out a reducing reaction; and a maturing step of raising the temperature of the reduced mixture to mature the reduced mixture is provided. A method of producing a plural type alloy nanoparticle, the method comprising producing a nanoparticle made of a plural type alloy through a reducing step of mixing one or more reverse micelle solutions (I) containing a metal salt with an reverse micelle solution (II) containing a reducing agent to carry out reducing treatment and a maturing step of carrying out maturing treatment is also provided.

Nanoparticle, method of producing nanoparticle and magnetic recording medium

The present invention is a magnetic particle coated material comprising: a first support having a magnetic layer formed on one surface thereof; and a second support having a magnetic layer formed on one surface thereof, wherein the first support and the second support are attached to each other so that the other surfaces thereof on which the magnetic layers are not formed face each other, and the magnetic layers comprise magnetic particles having a CuAu type or CuAu type ferromagnetic ordered alloy phase.

[object Object]

The invention provides methods for producing nanoparticles having a CuAu type or CuAu type magnetically hard ordered alloy phase. One method includes a step of reducing, in liquid phase, a base metal and then reducing, in liquid phase, a noble metal. Another method includes a step of reducing, in liquid phase, at first a base metal and a part of a noble metal, and then reducing, in liquid phase, a remainder of the noble metal in liquid phase.

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Kanagawa, Japan

Koukichi Waki