Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A process of treating surfaces of silica glass or silicate glass, particularly in the course of preparing an internal surface of a tubular substrate for subsequent coating during the manufacture of optical waveguides, comprising the steps of introducing to the surface to be treated a gaseous medium containing at least one component from which hydrogen fluoride is formed when the temperature of the gaseous medium exceeds a predetermined level; raising the temperature of an etching zone extending only over a portion of the surface to at least the predetermined level to form hydrogen fluoride in the gaseous medium and have the same etch the surface only at the etching zone; and effecting relative movement between the etching zone and the surface until all portions of the latter have been etched.
Claim 2
Dependent Claim
130 words
A process of treating surfaces of silica glass or silicate glass, particularly in the course of preparing an internal surface of a tubular substrate for subsequent coating during the manufacture of optical waveguides, comprising the steps of introducing to the surface to be treated a gaseous medium containing at least one component from which hydrogen fluoride is formed when the temperature of the gaseous medium exceeds a predetermined level; raising the temperature of an etching zone extending only over a portion of the surface to at least the predetermined level to form hydrogen fluoride in the gaseous medium and have the same etch the surface only at the etching zone; and effecting relative movement between the etching zone and the surface until all portions of the latter have been etched.
Claim 3
Dependent Claim
32 words
The process as defined in claim 1, wherein said raising step includes heating the etching zone to a temperature at which oxygen present at the etching zone reacts with the aforementioned component.
Claim 4
Dependent Claim
18 words
The process as defined in claim 2, wherein said introducing step includes incorporating oxygen in the gaseous medium.
Claim 5
Dependent Claim
76 words
The process as defined in claim 1, wherein said raising step includes heating the etching zone to a temperature at which oxygen present at the etching zone oxidizes silicon tetrafluoride developed during the etching to silicon dioxide which permeates the gaseous medium and deposits on the surface outside of the etching zone together with fluorine present in the gaseous medium to form a fused vitreous fluorine-doped silica layer on the previously etched portion of the surface.
Claim 6
Dependent Claim
68 words
The process as defined in claim 1, wherein said introducing step includes feeding the gaseous medium into the interior of a tubular substrate; wherein said raising step includes applying heat to the exterior of the tubular substrate at the etching zone; and wherein said effecting step includes effecting relative movement between the zone at which heat is applied and the tubular substrate longitudinally and circumferentially of the latter.
Claim 7
Dependent Claim
23 words
The process as defined in claim 1, wherein the component is a partially fluorinated hydrocarbon compound having at least one residual hydrogen atom.
Claim 8
Dependent Claim
43 words
The process as defined in claim 1, wherein the gaseous medium contains at least two components reactable with one another to form hydrogen fluoride, one of the components being at least partially fluorine-substituted hydrocarbon compound and the other component being a hydrogen-containing compound.
Claim 9
Dependent Claim
21 words
The process as defined in claim 1, wherein said introducing step includes entraining vapor of the component in a carrier gas.
Claim 10
Dependent Claim
32 words
The process as defined in claim 8, wherein the entraining step includes passing oxygen as the carrier gas through a liquid body containing the component for entraining vapor of the component therein.
Claim 11
Dependent Claim
26 words
The process as defined in claim 9, wherein the liquid body contains at least one partially fluorinated hydrocarbon compound having at least one residual hydrogen atom.
Claim 12
Dependent Claim
27 words
The process as defined in claim 9, wherein the liquid body contains at least one at least partially fluorinated hydrocarbon compound and at least one hydrogen-containing compound.