Basic additives for silica soot compacts and methods for forming optical quality glass

Patent metadata

Field	Value
Publication number	US-2018148366-A1
Application number	US-201715824241-A
Country	US
Kind code	A1
Filing date	Nov 28, 2017
Priority date	Nov 30, 2016
Publication date	May 31, 2018
Grant date	—

Abstract

A method for forming an optical quality glass is provided. The method includes contacting silica soot particles with a basic additive, forming a silica soot compact, and removing the basic additive from the silica soot compact. A method of forming a cladding portion of an optical fiber preform is also provided.

First claim

What is claimed is:

1 . A method of forming optical quality glass, the method comprising:
contacting silica soot particles with a basic additive; forming a silica soot compact; and removing the basic additive from the silica soot compact.

2 . The method of claim 1 , wherein contacting silica soot particles with a basic additive increases the pH of the silica soot particles to between about 7.0 and about 10.

3 . The method of claim 1 , wherein contacting silica soot particles with a basic additive increases the pH of the silica soot particles to between about 7.5 and about 9.5.

4 . The method of claim 1 , wherein contacting silica soot particles with a basic additive increases the pH of the silica soot particles to between about 8.0 and about 9.0.

5 . The method of claim 1 , wherein contacting silica soot particles with a basic additive comprises adding between about 1 ppm and about 2500 ppm of the basic additive to the silica soot particles.

6 . The method of claim 1 , wherein contacting silica soot particles with a basic additive comprises adding between about 10 ppm and about 2000 ppm of the basic additive to the silica soot particles.

7 . The method of claim 1 , wherein contacting silica soot particles with a basic additive comprises adding between about 50 ppm and about 1500 ppm of the basic additive to the silica soot particles.

8 . The method of claim 1 , wherein contacting silica soot particles with a basic additive comprises adding between about 100 ppm and about 1000 ppm of the basic additive to the silica soot particles.

9 . The method of claim 1 , wherein the density of the silica soot compact is less than about 1.00 g/cm 3 .

10 . The method of claim 1 , wherein the density of the silica soot compact is between about 0.40 g/cm 3 and about 0.90 g/cm 3 .

11 . The method of claim 1 , wherein the density of the silica soot compact is between about 0.60 g/cm 3 and about 0.85 g/cm 3 .

12 . The method of claim 1 , wherein the basic additive is selected from the group consisting of an ammonium salt, a sodium salt and a potassium salt.

13 . The method of claim 12 , wherein the basic additive is an ammonium salt selected from the group consisting of ammonium carbonate, ammonium bicarbonate, ammonium hydroxide.

14 . The method of claim 12 , wherein the basic additive is a sodium salt selected from the group consisting of sodium carbonate, sodium bicarbonate, sodium hydroxide.

15 . The method of claim 12 , wherein the basic additive is potassium hydroxide.

16 . The method of claim 1 , wherein the basic additive is a gas.

17 . The method of claim 16 , wherein the gas is an ammonia-containing gas.

18 . The method of claim 1 , wherein contacting the silica soot particles with a basic additive comprises contacting the silica soot particles with a basic additive in the absence of a solvent.

19 . The method of claim 18 , wherein contacting the silica soot particles with a basic additive in the absence of a solvent further comprises heating the silica soot particles and the basic additive.

20 . The method of claim 1 , wherein forming a silica soot compact comprises pressing the silica soot particles over an outer layer of a substrate to form at least a portion of an optical fiber preform.

21 . The method of claim 1 , wherein removing the basic additive comprises heating the silica soot compact.

22 . The method of claim 21 , wherein heating the silica soot compact comprises heating to a temperature above about 200° C. at a rate of less than about 10° C. per minute.

23 . The method of claim 21 , wherein heating the silica soot compact comprises heating to a temperature above about 200° C. at a rate of about 1° C. per minute to about 5° C. per minute.

24 . The method of claim 1 , further comprising sintering the silica soot compact to form a glass article.

25 . A method of forming a cladding portion of an optical fiber preform, the method comprising:
positioning a partially manufactured optical fiber preform in an inner cavity of a mold body; contacting silica soot particles with a basic additive; after contacting the silica soot particles with the basic additive, loading the mold body with the silica soot particles; compressing the silica soot particles in a radial direction to form a silica soot compact; and removing the basic additive from the silica soot compact.

26 . The method of claim 25 , wherein contacting silica soot particles with a basic additive increases the pH of the silica soot particles to between about 7.0 and about 10.

27 . The method of claim 25 , wherein contacting silica soot particles with a basic additive increases the pH of the silica soot particles to between about 7.5 and about 9.5.

28 . The method of claim 25 , wherein contacting silica soot particles with a basic additive increases the pH of the silica soot particles to between about 8.0 and about 9.0.

29 . The method of claim 25 , wherein contacting silica soot particles with a basic additive comprises adding between about 1 ppm and about 2500 ppm of the basic additive to the silica soot particles.

30 . The method of claim 25 , wherein contacting silica soot particles with a basic additive comprises adding between about 10 ppm and about 2000 ppm of the basic additive to the silica soot particles.

31 . The method of claim 25 , wherein contacting silica soot particles with a basic additive comprises adding between about 50 ppm and about 1500 ppm of the basic additive to the silica soot particles.

32 . The method of claim 25 , wherein contacting silica soot particles with a basic additive comprises adding between about 100 ppm and about 1000 ppm of the basic additive to the silica soot particles.

33 . The method of claim 25 , wherein the density of the silica soot compact is less than about 1.00 g/cm 3 .

34 . The method of claim 25 , wherein the density of the silica soot compact is between about 0.40 g/cm 3 and about 0.90 g/cm 3 .

35 . The method of claim 25 , wherein the density of the silica soot compact is between about 0.60 g/cm 3 and about 0.85 g/cm 3 .

36 . The method of claim 25 , wherein the basic additive is selected from the group consisting of an ammonium salt, a sodium salt and a potassium salt.

37 . The method of claim 36 , wherein the basic additive is an ammonium salt selected from the group consisting of ammonium carbonate, ammonium bicarbonate, ammonium hydroxide.

38 . The method of claim 36 , wherein the basic additive is a sodium salt selected from the group consisting of sodium carbonate, sodium bicarbonate, sodium hydroxide.

39 . The method of claim 36 , wherein the basic additive is potassium hydroxide.

40 . The method of claim 25 , wherein the basic additive is a gas.

41 . The method of claim 40 , wherein the gas is an ammonia-containing gas.

42 . The method of claim 25 , wherein contacting the silica soot particles with a basic additive comprises contacting the silica soot particles with a basic additive in the absence of a solvent.

43 . The method of claim 42 , wherein cont

Assignees

• Corning Inc

Inventors

• Dawes Steven Bruce
• Hogue Lisa Ann
• Hrdina Kenneth Edward
• Vemury Srinivas

Classifications

• C03C3/06 Primary

  with more than 90% silica by weight, e.g. quartz {(C03C3/045 takes precedence)} · CPC title

• C03B19/066

  for the production of quartz or fused silica articles (other processes specially adapted for the production of quartz or fused silica articles C03B20/00) · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• C03B37/018

  by glass deposition on a glass substrate, e.g. by {inside-, modified-, plasma- or plasma modified-} chemical vapour deposition {[ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod} (C03B37/016 takes precedence; surface treatment of glass by coating with glass C03C17/02) · CPC title

• C03B37/01282 Primary

  by pressing or sintering, e.g. hot-pressing · CPC title