Method for suppressing corrosion of glass

Patent metadata

Field	Value
Publication number	US-10017693-B2
Application number	US-201615200272-A
Country	US
Kind code	B2
Filing date	Jul 1, 2016
Priority date	Jan 27, 2014
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

To provide a method for suppressing corrosion of glass to be in contact with a liquid material containing fluoride ions or a condensate of gas vaporized therefrom, without adding an alkaline substance, and further without imposing restrictions on e.g. the temperature, the pH, the fluoride ion concentration and the water content.
A method for suppressing corrosion of glass to be in contact with either one or both of a liquid material containing fluoride ions and a condensate of gas vaporized from the liquid material,
wherein the liquid material contains a powder containing silicon dioxide, and the silicon dioxide is contained in a molar ratio of one or more times to the fluoride ions.

First claim

What is claimed is:

1. A method for suppressing corrosion of glass to be in contact with either one or both of a liquid material comprising fluoride ions and a condensate of gas vaporized from the liquid material, the method comprising:
adding a powder comprising silicon dioxide to a liquid material comprising fluoride ions; and
contacting the glass with the liquid material comprising the silicon dioxide or the condensate of gas vaporized from the liquid material comprising the silicon dioxide,
wherein
the silicon dioxide is contained in a molar ratio of one or more times to the fluoride ions, and
the liquid material comprises hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or boric acid, and has a pH of less than 7.

2. The method for suppressing corrosion of glass according to claim 1 , wherein the glass is provided on a portion, in an equipment or an apparatus for treating the liquid material, to be in contact with either one or both of the liquid material and the condensate.

3. The method for suppressing corrosion of glass according to claim 1 , wherein the silicon dioxide is contained in an amount of at least 60 mass % based on 100 mass % of the powder.

4. The method for suppressing corrosion of glass according to claim 1 , wherein the powder has an average particle size of at most 0.5 mm.

5. The method for suppressing corrosion of glass according to claim 1 , wherein the concentration of the fluoride ions is at least 0.1 mass ppm.

6. The method for suppressing corrosion of glass according to claim 1 , wherein the liquid material comprises hydrochloric acid, and has a pH of less than 7.

7. The method for suppressing corrosion of glass according to claim 1 , wherein the liquid material comprises a fluorosurfactant.

8. The method for suppressing corrosion of glass according to claim 7 , wherein the fluorosurfactant is either one or both of ammonium perfluorooctanoate and ammonium perfluoro-3,6-dioxa-octanoate.

9. The method for suppressing corrosion of glass according to claim 1 , wherein the powder comprising silicon dioxide is a silica gel.

10. The method for suppressing corrosion of glass according to claims 1 , wherein the silicon dioxide is contained in a molar ratio of at most 120 times to the fluoride ions.

11. The method for suppressing corrosion of glass according to claim 1 , wherein the liquid material comprises sulfuric acid.

12. The method for suppressing corrosion of glass according to claim 1 , wherein the liquid material comprises nitric acid.

13. The method for suppressing corrosion of glass according to claim 1 , wherein the liquid material comprises phosphoric acid.

14. The method for suppressing corrosion of glass according to claim 1 , wherein the liquid material comprises boric acid.

Assignees

• Asahi Glass Co Ltd

Inventors

• Futagawa Norifumi

Classifications

• C09K15/02 Primary

  containing inorganic compounds · CPC title

• G02B1/14

  Protective coatings, e.g. hard coatings · CPC title

• C03C23/00

  Other surface treatment of glass not in the form of fibres or filaments · CPC title

• C03C15/00 Primary

  Surface treatment of glass, not in the form of fibres or filaments, by etching (etching or surface-brightening compositions, in general C09K13/00) · CPC title

• B01D15/02

  with moving adsorbents · CPC title