JPH0196032A - Production of glass - Google Patents

Abstract

PURPOSE:To contrive stable yield in the drying process of glass making by a sol-gel method, by introducing volatile liquid into both drying vessel and drier and allowing humidity in the vessel to be saturated and thereafter performing drying and producing glass. CONSTITUTION:In production of glass by a sol-gel method in which metal alkoxide is used as a staring raw material, volatile liquid such as water and alcohol is introduced as a dummy into both drying vessel and drier, and humidity in the vessel is allowed to be saturated and thereafter drying is performed. In this production of glass, syneresis water is not rapidly lost at an initial period of drying and drying yield is remarkably improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing glass.

[Summary of the invention]

In the production of glass by the sol-gel method using metal alkoxide as a starting material, the present invention involves filling a drying container and a drying machine with a volatile liquid such as water or alcohol as a dummy, saturating the humidity inside the container, and then drying. This is a method of manufacturing glass.

In the sol-gel method, the drying process is a key point in obtaining the bulk. U cracking is the biggest problem in synthesizing glass using the sol-gel method, and although it has become possible to create a bulk by adding fine particles, it cannot be said that this has been completely solved.

Cracks are particularly likely to occur in the early stages of drying. This is thought to be closely related to the syneresis water coming out of the wet gel. In the early stage of drying, if syneresis water is rapidly lost, the wet gel becomes very susceptible to cracking. In addition, in the early stage of drying, if the dryer or drying container has not reached saturated humidity, @ spring water will be used until the saturated humidity is reached, resulting in a rapid decrease in syneresis water.

Therefore, in the present invention, in order to saturate the inside of the drying container containing the wet gel, a volatile liquid such as water or alcohol is put into the drying container and dryer as a dummy, and the humidity inside the container is saturated before drying. It was to be. Therefore, in the early dry period! @ Serious spring water is no longer suddenly lost, resulting in an improvement in drying yield.

[Conventional technology]

In the manufacture of glass by the sol-gel method, conventionally, as in Japanese Patent Application Laid-Open No. 237577 (Toki et al.), drying was carried out without putting any volatile liquid that affected the drying atmosphere into the dryer.

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional technology, Δ warping is likely to occur in the early stage of drying (and a stable drying yield cannot be expected).

Therefore, the purpose of the present invention is to solve the above-mentioned point J, and its purpose is to add a dummy volatile liquid such as water or alcohol to the drying container and inside the dryer in order to saturate the humidity inside the dryer. By drying after saturating the humidity inside the container, syneresis water is not suddenly lost in the initial stage of drying, and a stable drying yield can be provided.

[Means for solving problems]

The method for producing glass of the present invention includes producing glass by a sol-gel method using metal alphoxide as a starting material.
It is characterized in that a volatile liquid such as water or alcohol is placed in the drying container and dryer as a dummy to saturate the humidity inside the container before drying.

[Effect]

According to the above configuration of the present invention, by putting a volatile liquid such as water or alcohol as a dummy in the drying container and the drying machine, and drying after saturating the humidity inside the container,
This can lead to an improvement in drying yield.

〔Example〕

Example 1 Tetraethoxysilane 17.91, 0.01 N hydrochloric acid aqueous solution 23.51 and silica fine particles (Aerosil 0X-
50 (manufactured by Degussa, West Germany) were mixed and vigorously stirred for 1 hour to obtain a hydrolyzed solution. The obtained sol was irradiated with ultrasonic waves (28 kHz, 1200 W) for 4 hours to crush and disperse coarse particles. The sol obtained by ultrasonic irradiation was then taken into a centrifugal bone 1IIII machine and heated at 1500G for 15 minutes.
Apply centrifugal force for 1 minute to remove remaining coarse particles and foreign matter.
Removed. Next, the obtained sol was divided into 10 μm and 7 μm N 3
After passing through a pre-filter in the order of 11 μm, it was passed through a Membrane 5 μm filter.

The pH value of the obtained uniform sol was raised from 2.2 to 4.0 using 0.01 normal ammonia water. Furthermore, the obtained sol was taken into the centrifuge again and 1500G was
After applying the voltage for 5 minutes, the mixture was again passed through a 5-μm Membrane film and placed in a container measuring 30 cm x 30 cm x 10 cm, with 40 sheets having a thickness of 1 cm.

When the solution was left sealed overnight, the sol turned into a gel and a wet gel was obtained. I changed it to a straw hat with holes with an opening ratio of 0.3% and put it in the dryer. At the same time, a 20% ethanol aqueous solution was put into the 15ρ dryer. A dry gel was obtained by drying at 80'C for 2 weeks. The drying yield at this time was 100% with no cracks among 30 sheets.

The resulting dry gel was further dried at 200°C to completely remove remaining water. Put this in an atmospheric furnace and D
Sintering was performed at 1000°C in a ry-Air atmosphere. next,
When placed in a vacuum furnace and sintered at 1400''C in a vacuum, quartz glass was obtained.

Comparative Example 1 40 sheets of wet gel obtained by adding potatoes in the same manner as in Example 1 were replaced with a lid with holes with an opening ratio of 0.3%, placed in a dryer, and soaked with dummy water or A dry gel was obtained by drying at 6090 for 2 weeks without adding alcohol. The drying yield at this time was 75%, with 15 out of 40 pieces cracking.

〔Effect of the invention〕

In the present invention, in order to soak the wet gel in the drying container, a volatile liquid such as water or alcohol is put into the drying container and the drying machine as a dummy, and the humidity inside the container is saturated before drying. This eliminates the sudden loss of synervic water during the initial stage of drying, resulting in a significant improvement in drying yield.

that's all Applicant: Seiko Epson Corporation

Claims (1)

[Claims] In the production of glass by the sol-gel method using metal alkoxide as a starting material, a volatile liquid such as water or alcohol is placed as a dummy in the drying container and dryer, and the humidity inside the container is saturated before drying. A method of manufacturing glass.