JPH03141124A - Production of quartz glass preform and burner for producing quartz glass preform - Google Patents

Abstract

PURPOSE:To obtain a quartz glass preform suitable for even use of a slightly volatile doping material by containing the slightly volatile compound as a raw material in a multitubular burner for producing a cellular preform according to a vapor axial deposition method and additionaly providing a chamber for vaporizing the aforementioned compound and feeding the resultant vapor to a pipe in the burner. CONSTITUTION:A slightly volatile compound 2 (e.g. AlCl3) in glass raw materials is contained in a chamber 3, provided near the outlet of a multitubular burner 1 and communicating with at least one pipe of the multitubular burner 1 and a carrier gas 7 (e.g. Ar) is fed while heating the chamber 3 with a heater 8 to vaporize the slightly volatile compound 2. The resultant vapor is subsequently fed to a pipe (4a) of the multitubular burner 1. Glass raw materials [e.g. BBr3 (4b) and SiCl4 (4c)] other than the slightly volatile compound 2 and combustion gases such as oxygen gas (4b) and hydrogen gas (4d) are then respectively fed to other pipes of the multitubular burner 1 to react the glass raw materials in a flame 9. Thereby, formed fine glass particles 10 are deposited to prepared a cellular preform.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention is directed to the application of Alzo 3-B to a S which is used as a stress-applying base material for polarization-maintaining fibers.
The present invention relates to a method for manufacturing a quartz glass base material suitable for manufacturing a silica glass base material, and a burner for manufacturing a quartz glass base material suitably used in the method.

"Prior Art" Conventionally, ByOz 5ift glass has been mainly used as a stress-applying base material material for polarization maintaining fibers.

By doping boron (as B*O*) into quartz glass, the coefficient of thermal expansion of quartz glass is changed, and by melting and integrating this with another quartz glass, stress is created in the base material or fiber. Distortion can be applied.

However, since boron-doped silica glass has a refractive index that decreases depending on the boron doping ring, this boron-doped stressed base material has the disadvantage that its applications are limited.

Therefore, there is a need for a technique for manufacturing silica glass in which the refractive index is controlled by increasing the refractive index of boron ponds and combining them with other dopants when doping with boron.

Dopants that avoid increasing the refractive index of quartz glass and do not adversely affect the thermal expansion coefficient changed by boron doping include GeOt and At.

There is 03.

Among these dopants, G e Ot has a temperature dependence in its reaction rate, so when the gas phase axis is attached to the ITI method,
A material with a radial index distribution is formed.

On the other hand, although AltOa does not have the above-mentioned drawbacks, the aluminum compound used as the raw material generally has a boiling point and sublimation point in the high temperature range of 150°C or higher, so it is suitable for stable supply of raw material gas to the gas phase reaction system. There was a problem that it was difficult to obtain the desired object.

The present invention was made in view of the above circumstances, and therefore Alz0
It is an object of the present invention to provide a method for producing a quartz glass mother H suitable for cases such as No. 3 in which the raw material compound of the material to be doped into the quartz glass is a difficult-to-vaporize compound that is difficult to vaporize.

"Means for Solving the Problem" The invention as set forth in claim 1 provides a porous base material by supplying a glass raw material to a multi-tube burner and depositing glass fine particles produced by flame hydrolysis or thermal oxidation reaction. In the method for producing a quartz glass base material, a non-vaporizable compound of the glass raw materials is placed in a chamber provided near the outlet of the multi-tube burner and communicating with at least one pipe of the multi-tube burner. and supplies a carrier gas while heating the chamber to vaporize the difficult-to-vaporize compound and send it to the conduit of the multi-tube burner. A glass raw material gas other than a compound and a combustion gas such as oxygen gas or hydrogen gas are supplied, a flame is formed in the multi-tube burner, and the glass fine particles are generated by reacting the glass raw material in the flame. The method for solving the above problem was to create a porous matrix by deposition.

Further, in this manufacturing method, as described in claim 2, the chamber containing the difficult-to-vaporize compound and at least one of the plurality of conduits are communicated with the chamber.
Connect other pipes to the supply lines for glass raw material gases other than evaporative compounds and combustion gases such as oxygen gas and hydrogen gas.
A burner for manufacturing a quartz glass mother is preferably used, which is equipped with multiple tubes, a carrier gas pipe line for supplying carrier gas into the chamber, and a heating device for heating the chamber.

Further, as described in claim 3, the burner for producing the quartz glass base material includes the chamber and the pipe line inserted into the chamber being formed of quartz glass, and the heating device being an infrared ray llll5Ijll device, and The infrared heating device may be configured to include a shift control mechanism that monitors the chamber internal pressure from a pressure gauge provided in the carrier gas supply pipe and controls the amount of infrared light of the infrared heating device to maintain a constant pressure. .

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining an example of a burner for producing quartz glass according to the present invention, and reference numeral 1 in this figure indicates a burner for producing quartz glass (hereinafter referred to as burner).

This burner 1 communicates with a chamber 3 that accommodates a difficult-to-vaporize carboxylic substance 2 such as AlC1z or All3r*, and a pipe 4a at the center +1< among six pipes 18 to 4f. In addition, the other pipes 4b to 1" are connected to the supply lines 5b to 5r for glass raw #1 gas other than the difficult-to-gasify compound 2, and combustion gas such as oxygen gas or hydrogen gas. I
ET pipe 6 and A gas (gear gas) in the chamber 3.
The chamber 3 is configured to include a carrier gas conduit 7 for supplying the gas, and a heating device 8 for heating the chamber 3.

As mentioned above, the difficult-to-vaporize chemical compound 2 is aluminum halide A Ic +3 (melting point 19
0℃, sublimation point 180℃) or AlBr, (melting point 9
75°C, boiling point 255°C). The gases that have vaporized both of these compounds are at a high temperature of nearly 200°C, so in order to supply them from a point away from the outlet of the multiple pipe 6, it is necessary to keep the intermediate piping at a temperature of 200°C or higher. Therefore, in the burner 1 according to this example, by providing the above chamber 3 near the outlet of the multiple tube 6, difficult-to-vaporize chemical compounds are removed near the outlet of the multiple tube 6. By vaporizing 2 and sending it into the conduit 4a of the multi-tube 6, the apparatus can be simplified by 11 times.

As shown in FIG.
ICh or A11lr3, second conduit 4 outside it
1) to [IB+':+, and S to the third conduit 4c outside thereof.
iC14, lit to the fourth conduit 4d on the outside, A' to the fifth conduit 4e on the outside, and 0 to the sixth conduit 4r on the outside. .

As the heating device 8, it is possible to use a direct heating device for the chamber 3 using a flame or an electric heater. 'Precise heat near the 1% point...It is difficult to control, and there is a possibility of sudden boiling, making it unsuitable for quantitatively supplying gas of difficult-to-vaporize gas. . Furthermore, direct heating is susceptible to thermal effects from the heated object and lacks stability. For these reasons, an infrared heating device is preferably used as the heating device 8.

Using this burner 1, A lyo, z-B tO3-9
In order to produce the glass base material 10, first, the chamber 3
The difficult-to-vaporize compound 2 is put into the container, and then the hard-to-vaporize compound 2 is heated by the heating device 8 to start vaporization. Next, Ar gas (carrier gas) is supplied into the chamber 3 through the carrier gas pipe 7 at a constant flow rate, and the gas of the Jlt vaporizable compound 2 is sent to the first pipe 4aL of the multiple pipe 6. , B to the pipes 4b to 4r of the multiple pipe 6
Brl, 5iCla, [1, A" and O2 gases were supplied to each of the 4" filters.

Next, the gas ejected from the outlet of the multi-tube 6 is combusted to generate an oxyhydrogen flame 9, and the AlCl3 fed into the oxyhydrogen flame 9 causes a reaction represented by the following formula (1), 2AIc 134-3Hto→ Al! 0, +-6H
CI... ・(1) S iC1,, +31'3 r+ Reaction of the following formulas (II) and (III) S 1C1-
+ 21-1, o → S io! +411 CI
--(II)2B +3 +3-f 311, O→
Bto 3+ 6H13r (Ill) and Tora (Ko B
t O3, Al t Oz doped and j-op f plus trivial☆.

A child IO is formed.

The second glass fine particles r-10 are attached and deposited on the surface of the starting material III4 placed near the oxyhydrogen flame 9fi, forming a porous base material +1. This porous base material 11 is rotated as shown by the arrow S in the figure, and is gradually arched in the direction [; depending on the deposition state of the glass fine particles 1O.

By these valley operations, Δl'zo 3-11103-3
10? A glass base material of this type is prepared. Obtained glass I
F) Since glass +4 is porous, it is heated in a sintering furnace to make it transparent to form transparent glass 1'.

FIG. 3 is a diagram showing an example of a burner pond according to the present invention.

This burner 12 includes a chamber 3 and =R1, a pipe line f1 in the brim made of quartz glass, and a heating device 8 and an infrared heating device F? Using l 3, red of 2;-C
The wire heating device 13 is provided with a control device 15 that monitors the chamber internal pressure from a pressure gauge 14 provided in the carrier gas pipe line 7 and controls the amount of infrared light of the infrared heating device 13 so as to maintain a constant pressure. .

This infrared heating device 13 includes an infrared lamp 16 and a reflecting mirror 17 provided on the back thereof. This reflecting mirror 17 is equipped with a concave curved reflecting surface in which A u having a good infrared reflectivity has been cultivated, and the infrared lamps 16 emitted from the infrared lamps 16 arranged at the point IvL of the reflecting mirror I7 are Infrared light is focused in chamber 3 through anti-th and t-
It's getting dark. Since the chamber 3 and the pipe line inserted therein are made of quartz glass with a low infrared absorption rate, the irradiated infrared rays are absorbed into the difficult-to-vaporize compound 2 in the chamber 3 without being affected by lit:I<. reaches S? Heat equivalent to in (
Increase n by 1111. The control device 15 monitors the chamber internal pressure from the pressure gauges 1. The amount of infrared light emitted is controlled.

In this burner 12, when the difficult-to-vaporize compound 2 in the chamber 3 is vaporized by receiving infrared light from the infrared lamp 16, the internal pressure of the chamber 3 increases, and the upper limit of this internal pressure is the carrier gas pipe. The infrared light from the infrared lamp 16 is detected by the pressure gauge 14 of 7 and transmitted to the control device 15 so that the chamber internal pressure is constant! 1 is controlled. Heating of the difficult-to-vaporize compound 2 using infrared rays can be controlled more accurately than the direct heating method using a heater. (The vaporization can be stopped immediately by stopping the irradiation.) Therefore, it is possible to easily keep the supply m of the vaporization gas of the difficult-to-vaporize compound 2 constant, and the vaporization can be stopped immediately by stopping the irradiation.
ltOz-Byo, 3-5io.

system glass can be produced.

"Example" A quartz glass base material based on Al t 03 B t O3S i O was prepared using a burner substantially similar to the burner shown in FIGS. 1 to 3.

The multi-tube (six-fold tube) had an outer diameter of 22 mmφ, and the chamber had a cylindrical shape with an outer diameter of 40 mmφ and a height of 1501 mm, and the IC1 was placed in this chamber to about 2/3 of its height. Chamber and many! ■The pipes and conduits are made of quartz glass.

A gas was supplied into this chamber at a rate of 0.112/min, and AlCl and gas vaporized in the chamber could be supplied from the central pipe of the multi-R tube.
77 other pipes have Ii [3r:+(0,16Q/
), S i C14 (0,412/m
in, ), It t(8, (H1/ sin,),
A "(1,5Q/min), 0 + (+2.OQ/
In addition, an infrared heating device of +'p +rq, the same as that shown in FIG. 3, was used.

Infrared R11! The device heats the inside of the chamber to A Ic Itノ>'<1. When the chemical gas is put into the 7ff line in the center of the multi-tube, the In order to form an oxy-hydrogen flame, flame hydrolysis or thermal oxidation warp, the obtained glass fine particles were made into 11 pieces, and the filter sleeves were made with an outer diameter of 701φ by the method. -ntcz-SiOt
A glass-based glass base material (base material) was prepared.

Next, the obtained porous base material was placed in a sintering furnace and made transparent to produce a transparent glass base material.

The refractive index of the transparent glass base material produced in this way is A
1.1.4512 to 1.4592 depending on the tope stirring”1
-1 was possible. Further, the refractive index distribution of this base material was uniform with no difference in both the radial direction and the length direction.

In addition, as a result of cutting this base material and measuring the coefficient of thermal expansion at multiple locations, the coefficient of thermal expansion of this base material was found to be approximately the same value as the stress base material of the conventional B, 03S IO system, and in the radial direction. and showed uniform values in the length direction.

1. Effects of the Invention As explained above, according to the present invention, L3.Ol,!:lXl,0. 1) It is possible to improve the productivity of stress-applying matrices.

Also, A101. short-tempered l
A chamber for vaporizing the T1 compound and supplying υ(υ) into the multiple tubes was provided, and a 7-nivarna was used. The supply system for volatile compound gas can be simplified.

Furthermore, an infrared heating device was installed to heat the difficult-to-vaporize compound by +111 infrared rays to vaporize it, and a control device was installed to monitor the chamber internal pressure and control the amount of infrared light so that the internal pressure remained constant. It is possible to easily maintain a constant gas supply volume and to fabricate quartz glass ITN4 with a uniform composition.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of a burner for producing a quartz glass base material according to the present invention, FIG. 2 is a sectional view taken along the line ■-n in FIG. 1, and FIG. FIG. 2 is a schematic configuration diagram showing an example of a pond for a burner for producing wood. 6...Multi-IR'i"?, 7. Carrier gas Tτ path, 8. Heating device, 9. Oxyhydrogen flame, 10. Glass fine $Q-f"-1ll. Porous matrix +4.13・Infrared heating device, l = 1
Pressure gauge 15...Restriction 11 device.

Claims (3)

[Claims] (1) A method for manufacturing a silica glass base material in which a porous base material is produced by supplying a glass raw material to a multi-tube burner and depositing glass fine particles generated by hydrolysis or thermal oxidation reaction, comprising: A difficult-to-vaporize compound of the glass raw materials is contained in a chamber provided near the outlet of the burner and communicated with at least one pipe of the multi-tube burner, and a carrier gas is supplied while heating the chamber. At the same time, the difficult-to-vaporize compound is vaporized and sent to the pipe line of the multi-tube burner, and glass raw material gas other than the difficult-to-vaporize compound, oxygen gas, hydrogen gas, etc. A porous base material is produced by supplying combustion gases, forming a flame in the multi-tube burner, and depositing glass fine particles generated by reacting glass raw materials in the flame. Method for manufacturing quartz glass base material. (2) A chamber containing a difficult-to-vaporizable compound and at least one of the plurality of pipes are communicated with the chamber, and the other pipe is connected to a frit gas other than the difficult-to-vaporize compound;
A quartz glass base comprising multiple pipes connected to a supply line for combustion gas such as oxygen gas and hydrogen gas, a carrier gas pipe line for supplying carrier gas into the chamber, and a heating device for heating the chamber. Burner for wood production. (3) The chamber and the pipe line inserted into the chamber are formed of quartz glass, the heating device is an infrared heating device, and the infrared heating device is provided with a pressure gauge provided in the carrier gas supply pipe line. 3. The burner for producing a quartz glass base material according to claim 2, further comprising a control mechanism for monitoring the chamber internal pressure and controlling the amount of infrared light from the infrared heating device so as to maintain a constant pressure.