JPS60264335A - Preparation of plate glass - Google Patents

Abstract

PURPOSE:In preparing plate glass by sol-gel method, to obtain plate glass efficiently and economically, by feeding a silica sol solution to an upright container divided in a beltlike way. CONSTITUTION:A metal alkoxide (e.g., ethyl silicate) is hydrolyzed, and, if necessary, silica fine powder is added to it, to prepare a silica sol solution. Then, the silica sol is packed into the upright container 2 divided in a beltlike way by the partition plates 3, the container is closed, and the silica sol is aged. Then, the silica sol is gelatinized with the advance of aging, and, when shrinkage starts slightly, a cover is changed with a porous cover (the partition plates 3 are removed, and preferably plastic sheets are inserted into the container instead of them), the gel is put in a dryer, and dried. Then, the prepared dried gel is taken out, and calcined according to a given program, to give plate glass.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a glass manufacturing method in which glass is obtained by gelling a silica sol solution, followed by drying and sintering, and more particularly to a method for manufacturing sheet glass.

[Prior art]

In recent years, glass products have come to occupy an important position in industry. For example, in the semiconductor industry, it is becoming increasingly important as a material for mask substrates, ports, furnace tubes, etc., and in optical wave technology, as a material for optical fibers.

Among such glass products, quartz glass is particularly important.

Generally, glass is obtained by a melting method, but this method has the disadvantage of increasing fuel costs and being expensive.

In contrast to this method, a method called the sol-gel method, in which glass is manufactured at a temperature below the melting point, is attracting attention.

A brief outline of this sol-gel method is as follows.

First, a suitable metal alkoxide (ethyl silicate) is hydrolyzed to create a sol solution.

Depending on the case, fine silica powder or the like may be added to this solution.

The obtained sol solution is poured into a mold and gelled.

After gelation, the desired glass can be obtained by drying and sintering.

When manufacturing sheet glass using such a sol-gel method, conventionally, a sol solution is placed in a container of an appropriate size,
After gelation, the gel was dried as it was to obtain a dry gel, and the resulting dry gel was sintered to obtain a sheet glass.

However, in this conventional method, the number of containers,
It took up a lot of space, required a large dryer, and was not suitable for mass production. When using branutic containers such as Nu, Tupperware, etc., the heat resistance is poor, the flatness deteriorates quickly, and it is impossible to use them many times.

When preparing the sol, the container must be horizontal and special care must be taken.

〔the purpose〕

The object of the present invention is to overcome the above-mentioned drawbacks in obtaining sheet glass by the sol-gel method.

, 1::・ [Summary] In the mass production method of plate glass of the present invention, silica sol obtained by the conventional method is placed in a container partitioned into a strip as shown in FIG. It is characterized by aging until it begins to shrink.

When it starts to shrink slightly, you can replace it with a lid with holes and start drying, or you can remove the cutting board and then replace the lid with holes and start drying. When removing the partition plate, it is necessary to cut off the plastic band to prevent the gel from getting stuck. In this case, there is space on both sides of the gel, which is very convenient because both sides can be dried evenly.

Moreover, it also has the advantage of faster drying speed.

Other drying methods that can be considered include a method in which air is introduced from one side of the container and vented to the other, or a method in which the deflated gel is taken out into a large container and dried.

If the dry gel obtained in this way is sintered according to a prescribed program, in the case of quartz glass, the
A glass body can be obtained at a low temperature of about 0°C.

〔Example〕

Commercially available ethyl silicate 8 and 002N hydrochloric acid, 72t
The mixture was stirred and mixed using a disilver for about 1 hour until it became a homogeneous solution, and hydrolysis was carried out.

After hydrolysis, further add Aerosil OX-50 (manufactured by Degussa)
Add 2 to 3 and stir and mix to obtain a uniform sol solution.

Ultrasonic waves were applied for 5 hours to further disperse the mixture evenly.

The sol solution thus obtained was adjusted to pH=4.8 with a 0.1N ammonia solution and placed in four containers divided into four strip-shaped spaces as shown in Figure 2. The height was set to 25°C. Since the partition plates were not completely in contact with each other, the height of the liquid level was all the same.

The outer frame of the container is made of a vinyl chloride plastic plate and is 20 mm wide and 30 mm high.

My father, the partition plate is made of polypropylene sheets with a thickness of 2I, and has a structure that allows for free cutting.After preparation, it was sealed and aged at -30℃ day and night, and it shrunk by about 5 inches. .

The gels in each of the four containers were then dried using separate processing conditions.

57 1) After aging, the closed condition was changed to a lid with a porosity of 05%, and the gel was dried in a drying oven at 45° C., and a dry gel was obtained for about 15 months.

2) After ripening, remove the partition plate, sandwich a band-shaped propylene sheet between the b seconds of the partition plate, make sure that the individual gels do not stick together, and cover with a lid with a pore size of 05 cm.
When dried in a drying oven at 5°C, a dry gel was obtained in about one month.

3) Remove the partition plate by applying pressure in the same manner as in 2 above, making sure that the individual gels do not stick together, and as shown in Figure 3.
Attach air inlets and outlets on the upper and lower sides of the outer container, place it in a dryer at 45℃, constantly check the humidity on the outlet side, and blow air at a rate of 100 m/min to half the humidity on the outlet side.
1 and dried, a dry gel was obtained in about one week.

4) After removing the partition plate in the same manner as above, the wet gel was placed in a large container as shown in Figure 4, covered with a lid with a porosity of 1, and dried in a dryer at 60°C for 10 days. A dry gel was obtained. In the figure, a 7-sized large container, an 8-f'i drying hole, and a 96-sized gel are shown, respectively.

When the dried gel thus obtained was sintered in a furnace according to the heating program shown in Fig. 5, quartz galanus of approximately 225 x 10 x 0.5 fi was obtained regardless of the drying treatment conditions. Ta.

The quartz glass was confirmed by measuring the density, 1-spectral characteristics, etc. of the quartz glass.

〔effect〕

As described above, according to the present invention, since the wide surface does not face the direction of gravity, there is no need to worry too much about the horizontal surface, and the volume of the dryer is 1710 mm compared to the conventional method.
It has the advantage of saving space and not requiring a large dryer.

If the drying temperature is high, in the conventional method, you had to worry about deformation of the container, but with the present invention, it is possible to convert the material into a -H gel, fix the shape, and then dry it in a separate container. Therefore, deformation of the drying container is not very important.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic structure of a container used in the present invention. FIG. 2 is a diagram showing a container with a removable partition plate used in the example. FIG. 3 is a diagram showing an apparatus in which the container shown in FIG. 2 is provided with an air inlet/outlet. FIG. 4 is a diagram showing a state in which the wet gel has been transferred to a large container. It is a diagram showing the @51\ld sintering program. 1.21' is a container, 31- is a partition plate 5.6 is an air inlet/outlet, 7-eyed dog-shaped valley device 8 is a drying hole, and 9 is a gel. Applicant Suwa Seikosha Co., Ltd.

Claims (1)

[Claims] A method for producing glass that is vitrified by charging a silica sol solution into a mold, gelling it, and then drying and sintering the gel, characterized in that the silica sol solution is charged into a container partitioned into a belt shape. Glass manufacturing method.