Method of making fused silica by decomposing siloxanes

Claim 2

In a method for making a non-porous body of high purity fused silica glass comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 ; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 ; (c) depositing said amorphous particles onto a support; and (d) either essentially simultaneously with said deposition or subsequently thereto consolidating said deposit of amorphous particles into a non-porous body; the improvement comprising utilizing as said silicon-containing compound in vapor form, a halide-free polymethylsiloxane, whereby no halide-containing vapors are emitted during the making of said non-porous body of high purity fused silica glass.

Claim 3

A method according to claim 1 wherein said polymethylsiloxane is hexamethyldisiloxane.

Claim 4

A method according to claim 1 wherein said polymethylsiloxane is a polymethylcyclosiloxane.

Claim 5

A method according to claim 3 wherein said polymethylcyclosiloxane is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, and mixtures thereof.

Claim 6

A method according to claim 1 wherein said gas stream is comprised of an inert gas.

Claim 7

A method according to claim 5 wherein said inert gas is nitrogen.

Claim 8

In a method for making a non-porous body of high purity fused silica glass doped with at least one oxide dopant comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 and a compound in vapor form capable of being converted through oxidation or flame hydrolysis to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 doped with an oxide dopant; (c) depositing said amorphous particles onto a support; and (d) either essentially simultaneously with said deposition or subsequently thereto consolidating said deposit of amorphous particles into a non-porous body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors from said silicon-containing compound are emitted during the making of said non-porous body of high fused silica glass.

Claim 9

In a method for making a non-porous body of high purity fused silica glass doped with at least one oxide dopant comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 and a compound in vapor form capable of being converted through oxidation or flame hydrolysis to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 doped with an oxide dopant; (c) depositing said amorphous particles onto a support; and (d) either essentially simultaneously with said deposition or subsequently thereto consolidating said deposit of amorphous particles into a non-porous body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors from said silicon-containing compound are emitted during the making of said non-porous body of high fused silica glass.

Claim 10

A method according to claim 7 wherein said polymethylsiloxane is hexamethyldisiloxane.

Claim 11

A method according to claim 7 wherein said polymethylsiloxane is a polymethylcyclosiloxane.

Claim 12

A method according to claim 9 wherein said polymethylcyclosiloxane is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, and mixtures thereof.

Claim 13

A method according to claim 7 wherein said compound in vapor form capable of being converted to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table is a halide-containing compound.

Claim 14

A method according to claim 7 wherein said compound in vapor form capable of being converted to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VB, and the rare earth series of the Periodic Table is a halide-free compound.

Claim 15

In a method for making optical waveguide fibers of high purity fused silica through the outside vapor deposition process comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 ; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 ; (c) depositing said amorphous particles onto a mandrel; (d) consolidating said deposit of amorphous particles into a non-porous, transparent glass body; and (e) and drawing optical waveguide fiber from said body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors are emitted during the making of said optical waveguide fibers.

Claim 16

In a method for making optical waveguide fibers of high purity fused silica through the outside vapor deposition process comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 ; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 ; (c) depositing said amorphous particles onto a mandrel; (d) consolidating said deposit of amorphous particles into a non-porous, transparent glass body; and (e) and drawing optical waveguide fiber from said body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors are emitted during the making of said optical waveguide fibers.

Claim 17

A method according to claim 13 wherein said polymethylsiloxane is hexamethyldisiloxane.

Claim 18

A method according to claim 13 wherein said polymethylsiloxane is a polymethylcyclosiloxane.

Claim 19

A method according to claim 15 wherein said polymethylcyclosiloxane is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, and mixtures thereof.

Claim 20

In a method for making optical waveguide fibers of high purity fused silica glass doped with an oxide dopant comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 and a compound in vapor form capable of being converted through oxidation or flame hydrolysis to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 doped with an oxide dopant; (c) depositing said amorphous particles onto a mandrel; (d) consolidating said deposit of amorphous particles into a non-porous transparent glass body; and (e) drawing waveguide fiber from said body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors from said silicon-containing compound are emitted during the making of said optical waveguide fibers.

Claim 21

In a method for making optical waveguide fibers of high purity fused silica glass doped with an oxide dopant comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 and a compound in vapor form capable of being converted through oxidation or flame hydrolysis to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 doped with an oxide dopant; (c) depositing said amorphous particles onto a mandrel; (d) consolidating said deposit of amorphous particles into a non-porous transparent glass body; and (e) drawing waveguide fiber from said body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors from said silicon-containing compound are emitted during the making of said optical waveguide fibers.

Claim 22

A method according to claim 17 wherein said polymethylsiloxane is hexamethyldisiloxane.

Claim 23

A method according to claim 17 wherein said polymethylsiloxane is a polymethylcyclosiloxane.

Claim 24

A method according to claim 19 wherein said polymethylcyclosiloxane is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, and mixtures thereof.

Claim 25

A method according to claim 17 wherein said compounding vapor form capable of being converted to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table is a halide-containing compound.

Claim 26

A method according to claim 17 wherein said compound in vapor form capable of being converted to at least one member of the group consisting of P 2 O 5 and a metal oxide which has a metallic component selected from Group IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, and the rare earth series of the Periodic Table is a halide-free compound.

Claim 27

In a method for making high purity fused silica glass through the outside vapor deposition process comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 ; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 ; (c) depositing said amorphous particles onto a mandrel; and (d) consolidating said deposit of amorphous particles into a non-porous, transparent glass body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors from said silicon-containing compound are emitted during the making of said high purity fused silica glass.

Claim 28

In a method for making high purity fused silica glass through the outside vapor deposition process comprising the steps of: (a) producing a gas stream containing a silicon-containing compound in vapor form capable of being converted through thermal decomposition with oxidation or flame hydrolysis to SiO 2 ; (b) passing said gas stream into the flame of a combustion burner to form amorphous particles of fused SiO 2 ; (c) depositing said amorphous particles onto a mandrel; and (d) consolidating said deposit of amorphous particles into a non-porous, transparent glass body; the improvement comprising utilizing as said silicon-containing compound in vapor form a halide-free polymethylsiloxane, whereby no halide-containing vapors from said silicon-containing compound are emitted during the making of said high purity fused silica glass.

Claim 29

A method according to claim 23 wherein said polymethylsiloxane is hexamethyldisiloxane.

Claim 30

A method according to claim 23 wherein said polymethylsiloxane is a polymethylcyclosiloxane.

Claim 31

A method according to claim 25 wherein said polymethylcyclosiloxane is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethylcyclotrisiloxane, and mixtures thereof.