Method for producing metal particles

Abstract

An object of the present invention is to provide a method for producing metal fine particles in which the particle diameter and its coefficient of variation are controlled. Using at least two fluids to be treated, which are fluids containing at least one metal and / or metal compound and fluids containing at least one reducing agent, the above-mentioned fluids to be treated are arranged in opposite directions, accessible and separated At least one of which rotates relative to the other is mixed in the thin film fluid formed between at least two processing surfaces to precipitate metal particles. At this time, the fluid to be treated of at least one of the fluid containing at least one metal and / or metal compound and the fluid containing at least one reducing agent contains a water-containing polyhydric alcohol mixed with water and a polyhydric alcohol, and does not contain monohydric Alcohol controls the particle size and variation coefficient of the deposited metal fine particles by controlling the ratio of water contained in the water-containing polyol.

Description

technical field [0001] The present invention relates to a method for producing metal fine particles. Background technique [0002] In recent years, metal particles have been sought in a wide range of fields such as catalysts, conductive materials, magnetic materials, secondary electron emitting materials, luminous bodies, heat absorbers, energy storage materials, electrode materials, colorants, etc. Various metal particles with different particle sizes. The production method of metal microparticles|fine-particles is roughly divided into a gas-phase method and a liquid-phase method. In the gas phase method, generally, a solution containing metal ions is sprayed into a high-temperature atmosphere and thermally decomposed. However, it is not only difficult to obtain particles with uniform particle diameters and crystallite diameters, but also the equipment tends to become large and energy costs The current situation is that the liquid phase method has become the mainstream. ...

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Problems solved by technology

[0004] The applicant of the present application provides a method for continuously and stably producing uniform and homogeneous metal fine particles as in Patent Document 6, but specifically does not disclose a method for controlling the particle diameter of the obtained metal fine particles or its coefficient of variation.

In particular, in paragraph [0153] of the description of Patent Document 6, there is "the above-mentioned solvent is not particularly limited as long as it is a solvent that can dissolve the above-mentioned metal compound, and examples thereof include water, organic solvents, etc.", or from " In terms of the solubility of the above-mentioned metal compounds, water, alcohol, and a mixed solution of water and alcohol are preferred", but there is no description of using a mixed solution of water and alcohol as a solvent and controlling the ratio of water in the mixed solution of water and alcohol. Description of the intention to control the particle size of the obtained metal fine particles or its coefficient of variation

[0005] In addition, Patent Document 5 proposes a method of using a mixed solvent of a monohydric alcohol and a polyhydric alcohol having 4 or less carbon atoms and a mixed solution of water, and describes that the particle size of the metal powder to be precipitated is controlled by controlling the mixing ratio of the mixed solvent and water. diameter, but there is no description of the intention to control the coefficient of variation of the particle diameter of the metal powder undergoing precipitation to less than 5%.

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