JPS58125634A - Preparation of doped silica glass - Google Patents

Abstract

PURPOSE:To obtain doped silica glass having excellent optical characteristics, by exposing a mixture containing a alkyl silicate and other metallic alkoxide to a gas containing steam prior to hydrolysis. CONSTITUTION:Inert gas or oxygen gas is introduced through the flow controller 1 into the bubbling vessel 2 and bubbled in the water 3 to saturate the gas with steam. The steam-containing gas is introduced through the connection pipe 6 into the reaction vessel 4 to contact the liquid mixture 5 of Si (OC2H5)4 and Ge(OC4H9)4 with the gas. A clear sol is obtained by the preliminary hydrolysis of the mixture liquid 5. In the sol, Si (OH)4 and Ge(OH)4 form a two-component sol mixed at a molecular level without causing phase separation. The sol is hydrolyzed to obtain transparent GeO2-doped silica, which is dried and calcined to transparent GeO2-doped silica glass.

Description

[Detailed description of the invention] This invention relates to a method for manufacturing Liliki glass.

Conventionally, when hydrolyzing a mixture containing an alkyl silicate and another metal alkoxide, the same method has been used.

If in contact with the mixed solution, add water or dilute ammonia water or
A hydrolysis reaction was carried out by adding M acid water little by little. In this case, ammonia solution or hydrochloric acid has the effect of promoting hydrolysis.

However, when the mixed liquid was hydrolyzed using this conventional method, there was a drawback that phase separation occurred in the mixed liquid.

For example st(oc2H5)4 and Ge (OC4Hg)
When a mixed solution (mixing ratio 9:l) with Ge(OC4 )
There was a drawback that only 1,) was phototranslated and hydrolyzed. For this reason, in the sol solution obtained by hydrolysis, S
i. (OH)4 and (OH)4 exist independently, and even in the glass body obtained by drying and sintering, GeO2 precipitates as a phase and opens up. There were drawbacks.

Therefore, the conventional hydrolysis method has the problem that doped silica glass having good optical properties cannot be obtained.

In order to eliminate these drawbacks, the present invention synthesizes a transparent sol-like material by giving way to the gas that accounts for water vapor before hydrolyzing a mixed solution containing an alkyl silicate and other metal alkoxides. Its purpose is to stop I'J5 from 111+11ml produced during hydrolysis, and to produce a doped silica that is transparent and has good optical properties.

The objective is to provide a glass body.

The figure shows an embodiment of the present invention, where ■ indicates a gas transfer regulator;
is a bubbling container, 8 is water, 4 is a reaction container, 5 is 5i
A mixture of (002H5)a and Gθ(OC4Hg)4,
6 is a connecting pipe, and 7 is an exhaust pipe. In the figure, an inert gas case or oxygen gas whose flow rate is controlled by a flow rate regulator l is sent into a bubbling container 2, and water vapor is allowed to cool down in the gas by bubbling in water 8, and then the water vapor is name,.

5i (002H
, )4 and Gθ(00,Ho)4 is exposed to the gas, and the mixture is expressed as % of the pre-hydrated molecules. The gas after the reaction is exhausted from the exhaust W7.

For example, every time in a bubbling container filled with water 51.

When argon gas is fed at a rate of 50/min and bubbled at 1 M degree and 50°C, approximately 12 mo1% of the argon gas is present.
Water vapor is released in the west. Before connecting this argon gas containing 12% H20, 51(OC2H5)4 and Gθ
(004H0), and were mixed at a ratio of 9:1 (volume ratio).
When the mixture was pre-hydrolyzed by soaking it in the argon gas for 5 hours at 30°C, the mixture became a transparent sol in about 1 hour. This transparent sol-like material is a two-component sol-like material in which 51(OH)4 and Gθ(OH)4 are mixed at the molecular level without phase separation. For this reason, this transparent sol-like material is
Even when dissolved with mo/% ammonia water, no phase separation occurred and a transparent G e O2 doped/Ritz gel was obtained. Further, this transparent doped silica gel body was sintered at 1500° C. for 2 hours, resulting in a transparent Geo 2 doped silica glass body having a refractive index of 1,462.

Even when titanium, aluminum, monophosphorous, antiseptic, antimony, soot, lead, and tantalum alkoxides are used instead of germanium alkoxide as residual alkoxides, transparent products can be obtained under the same reaction conditions. A sol-like body was obtained, which was further sintered to obtain a transparent doped silica glass body.

The doped silica glass body produced according to the present invention had extremely good compositional uniformity, and also had extremely high transmittance when a fine material was used as the alkoxide raw material.

A core material with a core diameter of 50 μm and an outer diameter of 125 μm was prepared by using the GeO2-doped silica glass body with a refractive index of 1°462 as a core material and a commercially available quartz nail as a cladding material.
The loss of an optical fiber of m is 5 dB/km
(wavelength fl, 85 μm).

As described above in 1-1, the doped silica of the present invention
...The glass manufacturing method does not cause phase separation,
Since the mixture can be hydrolyzed, there is an advantage that a doped silica glass body having a uniform material composition and good optical properties can be manufactured. The present invention has the advantage that a large amount of sol-like material can be synthesized at one time, so that doped silica glass bodies with good optical properties can be mass-produced. Furthermore, the use of doped silica glass produced in large quantities as an optical fiber core material has the advantage that affordable optical fibers can be produced in large quantities.

[Brief explanation of drawings]

1 is a diagram showing an embodiment of the present invention. l...Gas flow rate regulator, 2...Bubbling container,
3...Water, 4...Reaction container, 5...51 (OC2
Mixed enemy of H5)4 and C,e (004Hg)4, 6.
...Connection piping, 7...Exhaust manifold O Patent applicant: Nippon Telegraph and Telephone Public Corporation Continued from page 1 0 Inventor: Motohiro Nakahara 162 Bold Shirakata Shirane, Tokai-mura, Naka-gun, Ibaraki Prefecture Nippon Telegraph and Telephone Public Corporation Ibaraki Telecommunications Inside the research institute

Claims (1)

[Claims] 1. A mixed solution containing alkyl silicate and other Kinshin alkoxides is exposed to a gas containing water vapor to synthesize a transparent sol-like material, and then the sol-like material is hydrolyzed, dried, and sintered to form a transparent sol-like material. A method for producing doped silica glass, characterized in that it is made into a glass body.