Xerogel production method

Patent metadata

Field	Value
Publication number	US-9663376-B2
Application number	US-201514734400-A
Country	US
Kind code	B2
Filing date	Jun 9, 2015
Priority date	Jun 17, 2014
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A xerogel production method includes: adding, to water glass, a basic silicic acid solution having a sol with a particle size between a particle size of the water glass and a particle size of colloidal silica, to acidify and solate the water glass, and polycondensing the solated water glass at 20° C. to 90° C., to obtain a hydrogel; growing the hydrogel by leaving the hydrogel for a certain time period at a constant temperature; hydrophobizing the hydrogel; and drying the hydrophobized hydrogel.

First claim

What is claimed is:

1. A xerogel production method comprising:
adding, to water glass, a basic silicic acid solution having a sol with a particle size between a particle size of the water glass and 30 nm, to acidify and solate the water glass, and polycondensing the solated water glass at 20° C. to 90° C., to obtain a hydrogel;
growing the hydrogel by leaving the hydrogel for a certain time period at a constant temperature;
hydrophobizing the hydrogel; and
drying the hydrophobized hydrogel.

2. The xerogel production method according to claim 1 ,
wherein the water glass is acidified to a pH ranging from 5.0 to 8.0.

3. The xerogel production method according to claim 1 ,
wherein the particle size of the sol ranges from 1 nm to 30 nm.

4. The xerogel production method according to claim 1 ,
wherein the basic silicic acid solution has a concentration of silicic acid ranging from 13 wt % to 20 wt %.

5. The xerogel production method according to claim 1 ,
wherein the basic silicic acid solution has a pH ranging from 8.0 to 11.0.

6. The xerogel production method according to claim 1 ,
wherein when the hydrogel is hydrophobized, at least one of hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, trimethylchlorosilane, hexamethyldisilazane, or methyltrimethoxysilane is used.

7. The xerogel production method according to claim 1 ,
wherein when the hydrogel is hydrophobized, at least one of methanol, ethanol, 2-propanol, tert-butanol, or ethylene glycol is used.

8. The xerogel production method according to claim 1 ,
wherein when the hydrophobized hydrogel is dried, the hydrophobized hydrogel is dried at 100° C. to 200° C.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Oikawa Kazuma
• Sakatani Shigeaki
• Toyota Kei

Classifications

• B01J13/0091

  Preparation of aerogels, e.g. xerogels · CPC title

• C01B33/16 Primary

  Preparation of silica xerogels · CPC title