Precise modifying method for fine particle dispersion liquid

Patent metadata

Field	Value
Publication number	US-2019031508-A1
Application number	US-201716074645-A
Country	US
Kind code	A1
Filing date	Feb 1, 2017
Priority date	Feb 2, 2016
Publication date	Jan 31, 2019
Grant date	—

Abstract

A method for modifying a fine particle dispersion liquid has excellent dispersibility and dispersion stability. In this method for modifying a fine particle dispersion liquid having improved fine particle dispersibility, impurities included in an agglomeration of fine particles contained in the fine particle dispersion liquid are released into the dispersion liquid by applying physical energy to the agglomeration and performing dispersion processing for dispersion into particles that are smaller than the agglomeration of fine particles. The impurities are removed from the dispersion liquid by means of a removal unit provided with a filtration membrane before reagglomeration is caused by the impurities.

First claim

1 . A method for reforming a fine particle dispersion solution, wherein
in the method for reforming the fine particle dispersion solution with which dispersion property of the fine particles is enhanced, a physical energy is applied to an aggregate of the fine particles included in the fine particle dispersion solution thereby carrying out a dispersion process to disperse the aggregate of the fine particles to smaller particles than the said aggregate of the fine particles, thereby discharging impurities having been included in the aggregate into the dispersion solution, and before re-aggregation by the impurities takes place entirely, a removal process to remove the impurities from the dispersion solution is carried out by a removing unit.

2 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein
the impurities comprises in-solution impurities present in the dispersion solution independent of the aggregate and in-particle impurities present in the aggregate, and the method comprises processes of: discharging the in-particle impurities from the aggregate to the dispersion solution by the dispersion process thereby changing them to the in-solution impurities; transporting the dispersion solution after the discharge process to the removing unit before re-aggregation by the in-solution impurities takes place entirely; and carrying out removal process to remove the in-solution impurities from the dispersion solution by the removing unit.

3 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein the dispersion process and the removal process are carried out continuously and repeatedly.

4 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein the removing unit is equipped with a filtration membrane, and the impurities are removed from the dispersion solution by using the filtration membrane.

5 . The method for reforming the fine particle dispersion solution according to claim 4 , wherein the filtration membrane is an ultrafiltration membrane, and the dispersion solution is supplied to the filtration membrane to carry out filtration by a cross-flow method so that the impurities are removed from the dispersion solution.

6 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein the removal process to remove the impurities from the dispersion solution is started within 3 seconds after the impurities are discharged into the dispersion solution.

7 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein dispersion property of fine particles in the fine particle dispersion solution is controlled by controlling at least any one of a path length, a flow rate, a flow amount, a fluid pressure, and a temperature in a just-before transporting path to send the dispersion solution after the impurities are discharged thereinto to the removing unit.

8 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein the dispersion process is a process to apply the physical energy to the aggregate by a rotation type disperser which rotates a stirring blade in the dispersion solution, and the dispersion process is carried out with setting a circumferential velocity of the stirring blade at 10 m/sec or more.

9 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein the dispersion property of the fine particles in the fine particle dispersion solution is controlled by controlling pH of the fine particle dispersion solution obtained after the removal process.

10 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein a primary particle diameter of the fine particle is 200 nm or less.

11 . The method for reforming the fine particle dispersion solution according to claim 1 , wherein the fine particle is a metal fine particle, an organic substance fine particle, or an oxide fine particle.

12 . A method for producing a fine particle dispersion solution, wherein
the said method comprises the method for reforming the fine particle dispersion solution according to claim 1 and a process to obtain a dispersion solution before carrying out the reformation method, and the said process to obtain the dispersion solution is a process in which a fine particle raw material solution including at least a raw material of the fine particle is mixed with a fine particle separating solvent including at least a fine particle separating substance to separate the fine particle in between processing surfaces which are disposed so as to be able to approach to and separate from each other as well as to rotate relative to each other, whereby separating the fine particle in the mixed fluid thus formed.

13 . The method for reforming the fine particle dispersion solution according to claim 2 , wherein the dispersion process and the removal process are carried out continuously and repeatedly.

14 . The method for reforming the fine particle dispersion solution according to claim 2 , wherein the removing unit is equipped with a filtration membrane, and the impurities are removed from the dispersion solution by using the filtration membrane.

15 . The method for reforming the fine particle dispersion solution according to claim 3 , wherein the removing unit is equipped with a filtration membrane, and the impurities are removed from the dispersion solution by using the filtration membrane.

16 . The method for reforming the fine particle dispersion solution according to claim 2 , wherein the removal process to remove the impurities from the dispersion solution is started within 3 seconds after the impurities are discharged into the dispersion solution.

17 . The method for reforming the fine particle dispersion solution according to claim 3 , wherein the removal process to remove the impurities from the dispersion solution is started within 3 seconds after the impurities are discharged into the dispersion solution.

18 . The method for reforming the fine particle dispersion solution according to claim 4 , wherein the removal process to remove the impurities from the dispersion solution is started within 3 seconds after the impurities are discharged into the dispersion solution.

19 . The method for reforming the fine particle dispersion solution according to claim 5 , wherein the removal process to remove the impurities from the dispersion solution is started within 3 seconds after the impurities are discharged into the dispersion solution.

20 . The method for reforming the fine particle dispersion solution according to claim 2 , wherein dispersion property of fine particles in the fine particle dispersion solution is controlled by controlling at least any one of a path length, a flow rate, a flow amount, a fluid pressure, and a temperature in a just-before transporting path to send the dispersion solution after the impurities are discharged thereinto to the removing unit.

Assignees

• M Technique Co Ltd

Inventors

• Enomura Masakazu
• Honda Daisuke

Classifications

• C01B13/16

  Purification · CPC title

• C01P2004/04

  obtained by TEM, STEM, STM or AFM · CPC title

• C01B13/14

  Methods for preparing oxides or hydroxides in general (particular individual oxides or hydroxides, see the relevant groups of subclasses C01B - C01G or C25B, according to the element combined with the oxygen or hydroxy group) · CPC title

• C01G49/00

  Compounds of iron · CPC title

• C01P2002/84

  by UV- or VIS- data · CPC title