Silica particle and method for producing the same

Patent metadata

Field	Value
Publication number	US-11866340-B2
Application number	US-202016997541-A
Country	US
Kind code	B2
Filing date	Aug 19, 2020
Priority date	Mar 24, 2020
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A silica particle includes: a quaternary ammonium salt, in which the following expressions are satisfied, 0.90≤F BEFORE /F AFTER ≤1.10, and 5≤F SINTERING /F BEFORE ≤20, in which F BEFORE represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing, which is obtained from a pore distribution curve in a nitrogen gas adsorption method, F AFTER represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles after washing, which is obtained from the pore distribution curve in the nitrogen gas adsorption method, and F SINTERING represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles before washing and after sintering at 600° C., which is obtained from the pore distribution curve in the nitrogen gas adsorption method.

First claim

What is claimed is:

1. Silica particles, comprising:
the silica particles containing a quaternary ammonium salt,

wherein the following expressions are satisfied,
0.90≤ F BEFORE /F AFTER ≤1.10, and

5≤ F SINTERING /F BEFORE ≤20,

wherein
F BEFORE represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing, which is obtained from a pore distribution curve in a nitrogen gas adsorption method;
F AFTER represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles after washing, which is obtained from a pore distribution curve in the nitrogen gas adsorption method; and
F SINTERING represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing and after sintering at 600° C., which is obtained from a pore distribution curve in the nitrogen gas adsorption method.

2. The silica particles according to claim 1 ,
wherein the quaternary ammonium salt contains a compound represented by a general formula (AM),

wherein, in the general formula (AM),
R 1 , R 2 , R 3 and R 4 each independently represents an optionally substituted alkyl group, aralkyl group or aryl group,
X − represents an anion, and
two or more of R 1 , R 2 , R 3 and R 4 may be linked to each other to form a ring.

3. The silica particles according to claim 2 ,
wherein, in the general formula (AM), R 1 , R 2 , R 3 and R 4 each independently represents an optionally substituted alkyl group having 1 or more and 16 or less carbon atoms, or an optionally substituted aralkyl group having 7 or more and 10 or less carbon atoms.

4. The silica particles according to claim 1 ,
wherein a number average particle diameter of the silica particles is 5 nm or more and 300 nm or less.

5. The silica particles according to claim 1 ,
wherein a number average particle diameter of the silica particles is 5 nm or more and 100 nm or less.

6. The silica particles according to claim 1 ,
wherein the silica particles satisfy the following expression:
0.01≤ N /(silica particle)×100≤1.00,

wherein
N represents an abundance of a nitrogen element derived from the quaternary ammonium salt detected by an oxygen and nitrogen analysis, and
(silica particle) represents a total weight of the silica particles.

7. The silica particles according to claim 1 ,
wherein an average pore diameter of the silica particle is 0.55 nm or more and 2.00 nm or less.

8. The silica particles according to claim 1 ,
wherein the silica particles are is hydrophobically treated silica.

9. The silica particles according to claim 1 ,
wherein the silica particles contain aluminum.

10. The silica particles according to claim 9 ,
wherein a ratio Si/Al of an abundance Si of a silicon element detected by an X-ray photoelectron spectroscopy to an abundance Al of an aluminum element detected by the X-ray photoelectron spectroscopy is 0.01 or more and 0.30 or less.

11. A method for producing the silica particles according to claim 1 , comprising:
preparing a silica particles-containing suspension; and then
mixing the silica particles-containing suspension with the quaternary ammonium salt to obtain a powder in which the silica particles are surface-treated with the quaternary ammonium salt using a supercritical fluid.

12. The method for producing the silica particles according to claim 11 , further comprising:
surface-treating the powder with an organosilicon compound in the supercritical fluid after the mixing.

Assignees

• Fujifilm Business Innovation Corp

Inventors

• Zenitani Yuka
• Sasaki Koji
• Takeuchi Sakae
• Eri Yoshifumi
• Mizuguchi Takahiro

Classifications

• C01B33/18 Primary

  Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C) · CPC title

• C09C1/3054

  Coating · CPC title

• C09C1/3081

  Treatment with organo-silicon compounds · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01P2006/16

  Pore diameter · CPC title