Method for producing silica sol

Patent metadata

Field	Value
Publication number	US-10604411-B2
Application number	US-201615748771-A
Country	US
Kind code	B2
Filing date	Jul 25, 2016
Priority date	Jul 31, 2015
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

[Problem] Provided is a method for producing a silica sol capable of providing consistent production of the silica sol having a uniform particle size of silica particles in any particle size of the silica particles.
[Solution] A method for producing a silica sol is a method including a step of mixing liquid (A) containing an alkaline catalyst, water, and a first organic solvent with liquid (B) containing an alkoxysilane or its condensate and a second organic solvent, and liquid (C1) having a pH of 5.0 or higher and lower than 8.0 and containing water or liquid (C2) containing water and being free of an alkaline catalyst to make a reaction liquid.

First claim

The invention claimed is:

1. A method for producing a silica sol, comprising a step of mixing
liquid (A) containing an alkaline catalyst, water and a first organic solvent with
liquid (B) containing an alkoxysilane or its condensate and a second organic solvent, and
liquid (C1) having a pH of 5.0 or higher and lower than 8.0 and containing water to make a reaction liquid.

2. A method for producing a silica sol, comprising a step of mixing
liquid (A) containing an alkaline catalyst, water and a first organic solvent with
liquid (B) containing an alkoxysilane or its condensate and a second organic solvent, and
liquid (C2) containing water and being free of an alkaline catalyst to make a reaction liquid.

3. The method for producing a silica sol according to claim 1 , wherein the liquid (C1) is free of an alkaline catalyst.

4. The method for producing a silica sol according to claim 1 , wherein a molar ratio of an alkoxysilane, water, an alkaline catalyst, and a first and a second organic solvents in the reaction liquid is (alkoxysilane):(water):(alkaline catalyst):(first and second organic solvents)=(1.0):(2.0 to 12.0):(0.1 to 1.0):(2.0 to 20.0).

5. The method for producing a silica sol according to claim 1 , wherein a molar ratio of a condensate of an alkoxysilane, water, an alkaline catalyst, and a first and a second organic solvents in the reaction liquid is, when the condensate is N-mer of the alkoxysilane (N represents an integer of 2 or more), (condensate of alkoxysilane): (water):(alkaline catalyst):(first and second organic solvents) =(1.0):(2.0×N to 12.0×N): (0.1 to 1.0):(2.0 to 20.0).

6. The method for producing a silica sol according to claim 1 , wherein temperatures of the liquid (A), the liquid (B), and the liquid (C1) or the liquid (C2) are each independently 0 to 70° C.

7. The method for producing a silica sol according to claim 1 , wherein the alkoxysilane is tetramethoxysilane.

8. The method for producing a silica sol according to claim 1 , wherein the alkaline catalyst is at least one of ammonia and an ammonium salt.

9. The method for producing a silica sol according to claim 8 , wherein the alkaline catalyst is ammonia.

10. The method for producing a silica sol according to claim 1 , wherein the first and second organic solvents are methanol.

Assignees

• Fujimi Inc

Inventors

• Ashitaka Keiji
• Ito Masaaki
• Shinoda Jun

Classifications

• C01B33/145 Primary

  Preparation of hydroorganosols, organosols or dispersions in an organic medium · CPC title

• B01J13/0026

  containing a liquid organic phase · CPC title

• C08L83/04

  Polysiloxanes · CPC title