JPS632819A - Silica glass manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing quartz glass by a sol-gel method.

[Conventional technology]

The conventional method for producing quartz glass by the Sol-Guru method is as described in detail in Japanese Patent Application No. 58-237577.
After uniformly dispersing ultrafine powdered silica in a hydrolyzed solution of metal alkoxide, a sol solution of which the pH of the dispersion was adjusted to 3 to 6 was charged into a container and gelled, dried,
It involves a process of sintering.

Using this method, one glass name tree can be obtained from one charged gel, and it can be applied to polishing plate-shaped glass, quartz substrates for engineering, etc., and can be manufactured by the sol-gel method. This is an effective method.

[Problem that the invention seeks to solve]

However, with the conventional manufacturing method, only one glass body can be obtained from 1:tl preparation containers, which is completely irrational when considering mass production.

Therefore, the present invention is intended to solve these conventional problems in mass production, and its purpose is to improve mass production by simultaneously obtaining two or more glasses #- from one preparation container. be.

c. Means for Solving Problems] The method for producing glass of the present invention includes at least a step of preparing a sol solution containing alkyl silicate and ultrafine powdered silica as main raw materials, a gelling process, a drying step, and a baking step of the gel. Gelation step 1'l- of sol solution in method for manufacturing quartz glass consisting of coalescence step
^ Te, PH! After gelling the adjusted sol solution in a container, the sol solution adjusted to TLv14 was poured on top of it and allowed to gel.

It is characterized by forming a gel in two or more layers.

[Execution row 1] Purified commercially available ethyl silica) 1.947 3.
2! An aqueous solution prepared by adding salt @ 3.2 mA to pure water was vigorously stirred to obtain a colorless and transparent homogeneous solution. There, ultrafine powdered silica (trade name CABO SIL L-(I), manufactured by Cabot Corporation) 9
7! Mt - Added slowly and stirred thoroughly.

Furthermore, this sol was irradiated with UK ultrasound for 3 hours.

A centrifugal force of 1500 G was applied to the sol solution for 15 minutes to remove lumps in the sol solution to obtain a highly homogeneous sol solution.

The sol solution to, i with normal ammonia water has a pH of 4.3.
Ic! After adjusting the size of the polypropylene container (width 30mm)
anX 30 cnt x height 1 (JcIn) K 7
An amount of 50 mA was charged, the lid was closed, and the container was left standing horizontally. After about 1 hour, the gel was cooled, so 750 mA of the sol solution adjusted to pH 4.3 was again poured onto the solidified gel and allowed to stand still in the water column. After about 1 hour, the bale gelatinized and a two-layer wet gel was obtained. The wet gel was aged for 5 days in a thermostatic chamber at 0.degree.

The aged wet glue was coated with 7 sheets with a porosity of 0.4% and dried in a drying room at 58°C. Drying was completed after about 5 days. Although the obtained dry gel had two layers, it was easily peeled off into one layer by applying a little force.

The dry gel was placed in a gas furnace and heated at 30'C/h.
The temperature was raised to 700°C at a rate of r. Pure helium gas t-IJ from 709℃! It started flowing into the furnace at a flow rate of /1rLin, the temperature was raised to 1400°C at a rate of 30°C/hr, and the temperature was maintained at 1400°C for 2 hours.

The resulting quartz glass μ width was 14. &m x 14.6c!
! The size was IX thickness 3.2u.

[Run 2] A sol solution having the same composition as in Run 1 was prepared, and gelled into three layers using the same method as in Run 1.

The wet gel was aged for 5 days in a thermostatic chamber at 30°C, then covered with a lid having a porosity of 0.4 cm and dried in a drying room at 58°C. Drying was completed after about 5 days.

The obtained dry gel had three layers, but when a little force was applied, the layers were easily peeled off without cracking.

91 width 1 by sintering the dry gel in a conventional manner.
4. &Fll x 14.6 x thickness 3. A quartz glass with a size of - was obtained.

[Run 3] Purified commercially available ethyl silicate 4.6! And 11.1!
An aqueous solution prepared by adding 11.1 mA of hydrochloric acid to pure water was vigorously stirred to obtain a colorless and transparent homogeneous IW solution. There, ultrafine powdered silica (trade name: Aerosil 0x, Degussa) 3. ygy
was gradually added and stirred thoroughly. Furthermore, this sol F [
Ultrasonic waves were irradiated for t-3 hours to ensure the dispersion of the ultrafine powdered silica. A total of 1500G centrifugal force is applied to the sol solution.
The clumps in the sol solution were removed for 5 minutes to obtain a highly homogeneous sol solution.

The sol solution has a total pH of 4.3K with 0.1N ammonia water.
l! After adjusting the Il, polypropylene container C width 30
Pour 750 mJ into a tube (cm x 30 cym x height 10 mouths), cover with a lid, and water! did. After about an hour, it gelled, so I used silicone spruce L/-(K?958) for mold release.
P.

After coating the gel (Shin-Etsu Chemical), 750 mA of the sol solution adjusted to pH 4.3 was again poured onto the fixed gel and allowed to stand in water. Approximately 10 minutes after gelatinization, a silicone spray for deafness was applied, and then 750 mA of the I'H4,3KJ prepared sol solution was again poured onto the solidified gel, and the gel was allowed to stand still in the water column. After about 1 hour, the gel was heated and a three-layered wet glue was obtained. The wet gel was aged in a thermostatic chamber at 30° C. for 5 days.

Put a lid on the aged wet gel with a porosity of 0.4% and
It was dried in a drying room at 8°C. Drying was completed after about 5 days. The obtained dry gel had three layers, and each layer had already peeled off by the end of the soft wire.

Sinter the dry gel using a conventional method.
@15cfRX A quartz glass with a size of 15 m x 3.4 u thick was obtained.

[Example 4] A sol solution having the same composition as in Example 3 was prepared, and five layers were gelled in the same manner as in Example 3.

The wet glue was aged for 5 days in a thermostatic chamber at 30° C., then dried in a drying room at 58° C. with a porosity of 0.4%. Drying was completed after about one month.

Five sheets of dry gel were obtained in a peeled state.

By sintering the dry gel in a conventional manner, the width of
A quartz glass with a size of cm×15α×thickness 3.4u was obtained.

[Actual tIfA column 5] Commercially available purified ethyl silicate, commercially available ethanol, water,
and commercially available electronic grade 29% anthonia water at 11 J and 16 J, respectively. &# 3.
8J and 0.45J were mixed, stirred vigorously for 4 hours, and kept in a cool dark place overnight to concentrate the silica fine particle dispersion.
After that, for stabilization, the pH was adjusted to t-4, which was used as the first gong. The average particle size of silica fine particles was measured using a light transmission type centrifugal sedimentation particle size distribution analyzer.

It was 0.40 fish.

Next, commercially available N ethyl silica) 4.87 and 0.02
The mixture was mixed with 6,157 ml of specified hydrochloric acid, stirred vigorously, and subjected to a hydrolysis reaction to form two liquids.

The first solution and the second solution were mixed, adjusted to pH 4.3 with 0.1N aqueous ammonia, and prepared in five layers as shown in Example 4 to form a gel.

The wet gel was aged for 5 days in a thermostatic chamber at 30° C. and dried in a drying chamber at 58° C. with a lid having a 1% porosity of 0.4 cm. Drying was completed after about one month. Five sheets of dry gel were obtained in a peeled state.

The dry glue is sintered in a conventional manner to have a width of 15 mm.
A quartz glass having a size of cHIX 153×3.4 mm thick was obtained.

〔Effect of the invention〕

As described above, according to the present invention, a sol solution containing at least alkyl silicate and ultrafine powder silica as main raw materials has a
In the sol solution gelling step of the quartz glass manufacturing method, which includes an IJ conditioning step, a gelling step, a drying step, and a sintering step of the gel, the PE[pi prepared sol solution is gelled in a container. After that, add a sol solution without adjusting the pH on top of it, make a gel ratio, and layer it in two or more layers to form a gel.This makes it possible to obtain two or more glass bodies at the same time from one preparation container. In addition, the number of sheets dried within a limited drying space has increased, which has had a great effect on tight production orders.

that's all

Claims (1)

[Claims] PH A method for producing quartz glass, which comprises gelling the prepared sol solution in a container, then charging a pH-adjusted sol solution thereon to gel it, and stacking it in two or more layers to form a gel. .