JPS603016B2 - Manufacturing method of glass for optical transmission lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing oxide soot, which is a material for phosphoric acid-based optical transmission lines.

Generally, phosphorus pentoxide (P205), gallium oxide (Ga2
03), phosphate glass whose main component is germanium oxide (Snake 02) is made by using the above-mentioned oxides as raw materials, respectively.
It is suitable as glass for optical fibers because it can be obtained in high purity through a gas phase chemical reaction in the form of chlorides of phosphorus, gallium, and germanium.

In addition, the above-mentioned phosphoric acid glass vitrifies at about 140° C. and does not contain alkali metal oxides that corrode quartz, so it can be melted for vitrification using a quartz crucible, which prevents contamination with impurities. It has the advantage that there is no fear of
It has excellent characteristics as a raw material for optical transmission fiber. However, among these raw material oxides, phosphorus pentoxide, which is a phosphorus oxide, is difficult to obtain as a single oxide because it evaporates easily. These composite oxides were obtained in the form of post-synthesized oxides, but since these composite oxides are greatly influenced by the temperature at which the oxide is formed, the mixed concentration of the component gases for the formation, etc., the composition of these composite oxides is It was difficult to control and stably obtain a good gait.

The present invention relates to a method for obtaining the above-mentioned composite oxide in good yield, and will be explained below with reference to the drawings. FIG. 1 shows a method for obtaining the above-mentioned composite oxide soot by a conventional flame hydrolysis method, and shows a simplified diagram of a piping system for obtaining oxide soot and a schematic diagram of a triple burner for flame hydrolysis.

In the figure, the supply valve 3 of the argon gas supply pipe 2 is opened to the evaporator 1 containing phosphorous oxychloride (POC13), and a predetermined amount of argon gas is supplied to make the argon gas support POC13. Also, gallium trichloride (Ga
Argon gas is supplied to the evaporator 4 in which C13) is housed.
The supply V supply valve 6 of the supply pipe 5 is opened to supply a predetermined amount of argon gas, and the GaC 13 is forced into the argon gas. At this time, the supply valve 9 of the argon gas supply V supply pipe 8 leading to the evaporator 7 containing germanium tetrachloride (WC14) is closed. In this way POC13 and G
Argon gas carrying aC13 is transferred to triple quartz burner 1.
Oxygen gas introduced into the inlet 1 1 of the triple quartz burner 10 from the oxygen gas supply pipe 12 and mixed with the oxygen gas introduced into the inlet 13 of the triple quartz burner 10 in order to efficiently carry out the flame hydrolysis reaction. At the same time, oxygen gas is introduced from the oxygen gas supply pipe 12 to the inlet 14 of the triple quartz burner 10. Further, hydrogen gas is supplied from the hydrogen gas supply joint pipe 15 to the inlet 16 of the triple quartz burner 10, and the hydrogen gas and oxygen gas are guided to the lower part B of the triple quartz burner, and the argon gas that has damaged the GaC 13 and POC 13 described above is introduced. A flame hydrolysis reaction is caused together with gas and oxygen gas to obtain GaP04, which is a composite oxide of phosphorus and gallium, and the collection container 1 is
It was collected on 7th. Next, the collection container 17 is replaced with another collection container, the supply valve 3 of the argon gas supply pipe 2 is opened, and argon gas is introduced into the evaporator 1 in which the POC 13 is accommodated, and the POC 13 is supported on the argon gas. At the same time, open the supply valve 9 of the argon gas supply V supply pipe 8.
Argon gas is introduced into the evaporator 7 containing C14, and GeC14 is forced into the argon gas. At this time Ga
The supply valve of the argon gas supply pipe 5 leading to the C13 evaporator 4 is kept closed. The argon gas carrying POC 13 and the argon gas carrying QC 14 are introduced into the inlet 11 of the triple quartz burner 10, and a flame hydrolysis reaction is caused at the tip of the burner in the same manner as described above.
Composite oxide soot of phosphorus and germanium (WP207)
into a collection container. The composite oxide soot of phosphorus and gallium GaP〇Z and the composite oxide soot of germanium WP207 obtained in this way were used as the core and cladding layers of the glass fiber so as to obtain the necessary refractive index, respectively. After weighing and mixing in a double quartz crucible, it was heated and vitrified to obtain a glass fiber.

However, in order to produce the above-mentioned composite oxide in high yield and with a constant composition using such flame hydrolysis method, it is necessary to control the flame temperature and the flow rate of the raw material gas to a constant value. There is a need to.

However, since the tip of the quartz burner is clogged with the above-mentioned oxides, it is difficult to control the flow rate of the raw material gas, and it is also difficult to control the temperature of the flame. The purpose of the present invention is to stabilize the composition of the above-mentioned oxide soot produced and to improve the yield. Manufacture of a new glass for optical transmission line by introducing M substance, oxygen gas and water vapor into a reaction tube, heating the reaction tube, and producing an acid imitation soot for glass formation through a gas phase chemical reaction inside the tube. It is intended to provide law.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a schematic diagram of an apparatus for producing an acid suiting suit for optical fiber glass according to the present invention.

In the figure, the supply valve 22 of the oxygen gas supply pipe 21 is opened as a carrier gas, and oxygen gas is introduced at a flow rate of 0.6 m/min to the evaporator 23 containing the POC 13 kept at a temperature of 40°C, and the oxygen gas is converted into oxygen gas. Bringing POC13 into focus. At the same time, the supply valve 25 of another oxygen gas supply pipe 24 is opened, and oxygen gas is introduced at a flow rate of 0.12 so/min to the evaporator 26 containing the WC 14 maintained at a temperature of 40 qo.
WC14 is supported on oxygen gas. At this time, GaC13
The supply valve 29 of the supply pipe 28 leading to the evaporator 27 containing the gas is kept closed. In this way, POC13, QC
Oxygen gas supporting each of 14 is introduced into the inlet 31 of the reaction tube 30. The tip C of the reaction tube is narrowed to prevent the oxide soot from scattering. In addition, oxygen gas is supplied to the evaporator 33 at a rate of 20 to 30'/Min from another oxygen supply joint pipe 32.
lead to. Pure water is stored in the evaporator 33 and is boiled by the heater 34 to generate water vapor. Therefore, the oxygen gas carrying water vapor is guided to the other introduction pipe 35 of the reaction tube 30. The reaction tube 30 is maintained at a temperature of about 1200° C. by a heating furnace 36. POC13 and QC1 introduced in this way are transported inside the reaction tube by oxygen gas and water vapor supporting POC13 and QC14, respectively.
The hydrolysis reaction of No. 4 occurs to produce a composite oxide soot of WP207, which is collected in the lower oxide soot collection container 37.

Next, the reaction tube 30 and collection container 37 are replaced with other reaction tubes and collection containers, respectively, and the supply of oxygen gas to the oxygen gas supply pipe 21 is performed.
The groove Δ valve 22 is opened, and oxygen gas is introduced into the evaporator 23 containing the above-mentioned POC 13 at a flow rate of 0.6 min, so that the oxygen gas carries the POC 13. At the same time, open the supply valve 29 of the oxygen gas supply pipe 28 and
Oxygen gas is introduced into the evaporator 27 containing GaC13 kept at a temperature of 140°C at a flow rate of Min, and the oxygen gas is
aC13 is damaged. At this time, the supply valve 25 of the oxygen gas supply pipe 24 leading to the evaporator 26 of the QC 14 is closed. In this way, the oxygen gas containing the POC 13 and GaC 13 is introduced into the inlet 31 of the reaction tube 30. At the same time, as described above, oxygen gas containing water vapor is introduced from the other inlet 35 of the heated reaction tube 30 at a flow rate of 20 to 30 [/Min, and the oxygen gas and water vapor are used to generate POC13 and By hydrolyzing GaC13,
GaP04 complex oxide soot is collected in a collection container 37. GaP04, GeP20 generated in this way
Collect the oxide soot of No. 7, weigh it to obtain the refractive index required for the core and cladding layers of the glass fiber, mix it in a quartz crucible, heat it to vitrify it, and then glass it. Fiber.

Some of the oxide soot produced in this manner may adhere to the walls of the reaction tube in a glassy state, but this amount is so small that it does not pose a problem. If the dimensions of the reaction tube are such that the inner diameter is 20 to 30 mm and the length is 300 to 60 mm, the reaction will occur sufficiently within the tube, and unreacted gas will not escape to the outside. As described above, according to the production method of the present invention, an oxide soot is produced by causing a gas phase chemical reaction in a heating reactor using water vapor, oxygen gas, and chloride of the glass raw material. Unlike the decomposition reaction, there is no fluctuation in the flow rate of the raw material gas due to clogging at the lower end of the burner, and the temperature of the heating furnace can be controlled with high accuracy, so the composition of the acid chloride soot produced is stable and This has the advantage that oxide soot can be produced with good yield.

In addition, the generated oxide soot may contain some moisture, but the moisture can be removed by blowing dry gas during the process of manufacturing glass fiber by melting it using a double quartz crucible. There is no problem when using it as a raw material.

[Brief explanation of the drawing]

Fig. 1 is a piping system diagram for raw material gas and a system diagram showing a triple quartz burner for producing oxide soot by the conventional flame hydrolysis method, and Fig. 2 explains the oxide soot production apparatus according to the present invention. This is a system diagram for 1: M°C13 evaporator, 2: Argon gas supply pipe, 3: Supply valve, 4: GaC13 evaporator, 5: Argon gas supply pipe, 6: Supply valve, 7: GeC14 evaporator, 8
: Argon gas supply groove pipe, 9: Supply joint valve, 10:
Triple quartz burner, 11: Inlet, 12: Oxygen gas supply pipe, 13, 14: Inlet, 15: 9 hydrogen gas supply pipes, 16
:Inlet, 17: Collection container, 21: Oxygen gas supply pipe,
22: Supply valve, 233POC13 evaporator, 24:
Oxygen gas supply pipe, 253 supply valve, 26: WC14
Evaporator, 27: GaC13 evaporator, 28: Oxygen gas supply pipe, 29: Supply valve, 30: Reaction tube, 31: Inlet, 32: Oxygen gas supply pipe, 33: Pure water evaporator, 34: Heater , 35: Inlet, 36: Heating furnace, 37: Collection container, A, B: Lower end of burner, C: Reaction tube tip. Figure 1 Figure 2

Claims (1)

[Claims] 1. When manufacturing oxide soot, which is a material for phosphoric acid-based optical transmission lines, chloride as a glass raw material, oxygen gas, and water vapor are introduced into a reaction tube, and the reaction tube is heated to produce gas phase chemistry inside the tube. A method for producing glass for optical transmission lines, characterized in that a glass-forming oxide soot is generated by a reaction and then vitrified.