Fine particle production method

Abstract

This fine particle production method involves a dissolving step in which a stirrer having a rotating stirring blade is used to dissolve at least one type of fine particle raw material in a solvent to obtain a fine particle raw material solution, and a precipitation step in which the fine particle raw material solution and at least one type of precipitation solvent for precipitating the fine particle raw material from the fine particle raw material solution are introduced between at least two treatment surfaces which are arranged oppositely one another, can move closer to and farther apart from one another, and at least one of which can rotate relative to the other, and the fine particle raw material solution and the at least one type of precipitation solvent are mixed in a thin film fluid formed between the at least two treatment surfaces, and the fine particles are precipitated. The stirring energy is determined by the stirring time conditions of the stirrer, the circumferential velocity conditions of the stirring blade, and the temperature conditions of the fine particle raw material solution, and in the dissolving step, the stirring energy is varied by changing at least one of the aforementioned conditions, and by changing the stirring energy, the degree of crystallization and the crystal form of the fine particles obtained in the precipitation step are controlled.

Description

technical field [0001] The present invention relates to a method for producing microparticles. Background technique [0002] Microparticles such as metals, oxides, pharmaceuticals, foods, cosmetics, and other living body ingestible substances, and pigments are required in a wide range of fields in the industry. [0003] The production method of microparticles generally uses a flask, a beaker, a tank, etc. as described in Patent Document 1 to perform reactions such as poor solvent method, crystallization, oxidation, and reduction. It is difficult to uniformly maintain the concentration and temperature in the container, so the particle size distribution of the obtained particles tends to widen. In addition, in the case of producing fine particles such as alloys and composite oxides containing two or more elements, it is difficult to obtain them in a homogeneous manner. Element ratios make particles. In addition, a method for producing microparticles using a microreactor as d...

AI Technical Summary

Problems solved by technology

[0005] However, even in the case of using the method described in Patent Document 3, it may be difficult to stably produce fine particles. When producing fine particles containing two or more molecules and elements, the local element ratio may vary. Even, it may be difficult to produce uniform and homogeneous particles

[0006] Furthermore, even if the method described in Patent Document 4 is used in combination, if the operating conditions of the device such as the formulation of the fluid to be processed, the liquid delivery amount, the temperature, and the rotational speed of the processing surface are simply changed, the resulting However, it is difficult to realize the desired crystallinity, crystal form or composition ratio of a specific crystal form, and no specific method for freely controlling the properties / characteristics of the particles such as crystallinity, crystal form or composition ratio of a specific crystal form has been disclosed, room for improvement

Images