Method for producing microparticles

Patent metadata

Field	Value
Publication number	US-9468891-B2
Application number	US-201214005506-A
Country	US
Kind code	B2
Filing date	Mar 21, 2012
Priority date	Mar 23, 2011
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

The problem addressed by the present invention is to provide a method for producing microparticles. Provided is a method that is for producing microparticles and that is characterized by containing at least the following two steps: (I) a step for preparing a microparticle starting material solution by dissolving at least one type of microparticle starting material in a solvent using high speed stirring or ultrasonic waves, and (II) a step for precipitating microparticles by mixing the microparticle starting material solution and at least one type of precipitation solvent for precipitating the microparticle starting material in a thin film fluid formed between at least two processing surfaces that are disposed facing each other, are able to approach/separate from each other, and of which at least one rotates relative to the others.

First claim

The invention claimed is:

1. A method for producing microparticles, comprising the steps of:
preparing a microparticle raw material solution by dissolving at least one microparticle raw material in a solvent by using a high speed agitator; and
mixing said microparticle raw material solution with at least one separating solution to separate said microparticle raw material in a thin film fluid formed between at least two processing surfaces, which are disposed in a position facing each other, and operable to approach to and separate from each other, at least one of which rotates relative to the other, thereby separating the microparticles, comprising the sub-steps of:
passing the separating solution through a first flow path into a space formed between the at least two processing surfaces to form the thin film fluid; and
passing the microparticle raw material solution through a second flow path into the space formed between the at least two processing surfaces, wherein the second flow path is independent of the first flow path, at least one opening which leads to the second flow path is arranged in at least any one of the at least two processing surfaces, and the microparticle raw material solution is introduced from the opening into the space formed between the at least two processing surfaces; and

directly controlling an introduction velocity of one of the microparticle raw material solution and the separating solution, which are introduced into the space between the at least two processing surfaces, so as to control a particle diameter of separated microparticles.

2. The method for producing microparticles according to claim 1 , wherein a circumferential velocity of an agitating blade during the time of dissolving the microparticle raw material into the solvent by using the high speed agitator is 1 or more m/second.

3. The method for producing microparticles according to claim 1 , wherein a particle diameter of the separated microparticles is controlled by preparing the microparticle raw material solution by using the high speed agitator.

4. The method for producing microparticles according to claim 1 , wherein the agitator comprises:
an admission port;
an agitation room with an impeller accommodated therein; and
a discharge port,
wherein the agitation room and the impeller rotate in opposite directions relative to each other, and a minute space is formed between an inner wall of the agitation room and an edge of the blade.

5. The method for producing microparticles according to claim 4 , wherein the agitator further includes a tank including an introduction fin and a circulation fin therein that are respectively spirally rolled along a longitudinal direction of a supporting trunk in opposite directions, the circulation fin being disposed outside of the introduction fin so that the fluid that is discharged from the discharge port is circulated to an upper part of the tank.

6. The method for producing microparticles according to claim 1 , wherein an introduction velocity of the separating solution is controlled.

7. The method for producing microparticles according to claim 1 , wherein an introduction velocity of the microparticle raw material solution is controlled.

8. The method for producing microparticles according to claim 1 , further comprising the step of:
controlling a circumferential velocity of an agitation blade of the agitator to control a particle diameter of separated microparticles.

Assignees

• Kuraki Jun
• Araki Kaeko
• Maekawa Masaki
• Honda Daisuke
• Enomura Masakazu
• M Technique Co Ltd

Inventors

• Kuraki Jun
• Araki Kaeko
• Maekawa Masaki
• Honda Daisuke
• Enomura Masakazu

Classifications

• B01J19/10 Primary

  employing sonic or ultrasonic vibrations · CPC title

• B01J2219/00779

  Baffles attached to the stirring means · CPC title

• B01F2215/0481

  Numerical speed values · CPC title

• B01J19/1887

  forming a thin film · CPC title

• B01F13/1027

  Operations & Transport · mapped topic