Alternative fluorinating agents for the production of fluorinated quartz glass

Patent metadata

Field	Value
Publication number	US-11884571-B2
Application number	US-202117395777-A
Country	US
Kind code	B2
Filing date	Aug 6, 2021
Priority date	Aug 6, 2020
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

A process for producing a fluorinated quartz glass is described, including providing an SiO 2 soot body; reacting the SiO 2 soot body with a fluorinating agent having a boiling point of greater than or equal to −10° C. to obtain a fluorinated SiO 2 soot body; and vitrifying the fluorinated SiO 2 soot body.

First claim

The invention claimed is:

1. A process for producing a fluorinated quartz glass, comprising:
(a) providing a SiO 2 soot body;
(b) reacting of the SiO 2 soot body with a fluorinating agent having a boiling point greater than or equal to −10° C. to obtain a fluorinated SiO 2 soot body;
(c) vitrifying the fluorinated SiO 2 soot body
wherein the fluorination provided in (b) is carried out with a fluorinating agent selected from a group consisting of:
i. oxygen-containing fluorinating agents;
ii. nitrile-containing fluorinating agents;
iii. mixtures of oxygen-containing and nitrile-containing fluorinating agents; and
characterized in that the oxygen-containing fluorinating agents are selected from a group consisting of:
i. Perfluoroketones of the general formula (I)
R F1 —CO—R F2   (I),

wherein R F1 is selected from a group consisting of perfluorinated carbon groups having 1 to 7 carbon atoms and fluorine; and R F2 is selected from a group consisting of perfluorinated carbon groups having 1 to 7 carbon atoms;
ii. Perfluoroethers of general formula (II)
R F1 —C(X 1 )(X 2 )O—R F2   (II),

wherein R F1 is selected from the group consisting of perfluorinated carbon groups having 1 to 7 carbon atoms and fluorine; R F2 is selected from the group consisting of perfluorinated carbon groups having 1 to 7 carbon atoms; and X 1 and X 2 are fluorine or CF 3 ;
iii. Hydrofluoroethers of the general formula (III)
R F1 —C(X 1 )(X 2 )O—R 2   (III),

wherein R F1 is selected from the group consisting of perfluorinated carbon groups having 1 to 7 carbon atoms and fluorine, R 2 is a non-fluorinated hydrocarbon group having 1 to 3 carbon atoms; and X 1 and X 2 are fluorine or CF 3 .

2. The process according to claim 1 , characterized in that the nitrile-containing fluorinating agents are selected from the group consisting of:
iv. Perfluoronitriles of the general formula (IV)
R F1 —C≡N

wherein R F1 is selected from the group consisting of a perfluorinated carbon group having 1 to 7 carbon atoms.

3. The process according to claim 1 , characterized in that the process (b) of reacting the SiO 2 soot body with the fluorinating agent having a boiling point greater than or equal to −10° C. is carried out at a temperature in a range from 700 to 1250° C.

4. The process according to claim 1 , characterized in that the process c. of vitrifying the fluorinated SiO 2 soot body is carried out at a temperature in a range from 1100 to 1500° C.

5. The process according to claim 1 , characterized in that the fluorinated SiO 2 soot body from process (b) is subjected to one or more further drying steps before vitrification in process step (c), whereby the drying is being carried out at a temperature in a range from 700 to 1200° C.

Assignees

• Heraeus Quarzglas

Inventors

• Ochs Stefan
• Trommer Martin
• Kayser Thomas

Classifications

• C03B20/00 Primary

  Processes specially adapted for the production of quartz or fused silica articles {, not otherwise provided for (C03B19/01, C03B19/066, C03B19/106, C03B19/12, C03B19/14, C03B37/00 take precedence)} · CPC title

• C03C3/06 Primary

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

• C03C2201/12

  containing fluorine (C03C2201/14 takes precedence) · CPC title

• C03C2203/40

  Gas-phase processes · CPC title

• C03B19/14 Primary

  by gas- {or vapour-} phase reaction processes · CPC title