JPS63195134A - Production of glass - Google Patents

Abstract

PURPOSE:To facilitate the production of large-sized glass preventing the generation of cracks in the aging and drying process, by producing a wet gel from a liquid sol having the composition of the objective glass and aging and drying the gel on a spongy substrate. CONSTITUTION:A liquid sol having the composition of objective glass is produced by using a metal alkoxide or a metal alkoxide and fine particles of metal oxide as main raw materials. The liquid sol is gelatinized to a wet gel in a closed vessel having a desired shape. The obtained wet gel is placed on a spongy substrate, aged, dried and sintered to obtain the objective glass. Since the aging and drying of the wet gel are carried out on a spongy substrate, the influence of the own weight of the wet gel on the wet gel strength in aging and on the shrinking force in drying can be decreased. Accordingly, the cracking of wet gel is suppressed to facilitate the production of a large-sized glass.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF APPLICATION ON CIll m The present invention relates to a method for producing glass by a sol-gel method.

[Conventional technology]

i! of glass by conventional sol-gel method! In Iin, metal alkoxides or metal alkoxides and gold l14111! A liquid sol with the desired glass component composition is prepared using fine particles of the compound as the main raw material, and the liquid sol is gelled in a sealed container with a filtration shape to produce a wet gel. ; The method was to prepare a dry gel by drying in a container or a container with a smooth bottom.

[Problem that the invention seeks to solve]

However, in the conventional technology mentioned above, when the wet gel becomes large, especially when the FJ becomes large,
During maturation of butogel, the balance between the wet gel mm and the structural strength of the wet gel is lost, and cracks occur from the contact surface with the container, and during drying, the wet gel shrinks as the drying process progresses. The problem is that it is difficult to increase the size (particularly thick ones) because the shrinkage force is smaller than the frictional force with the contact surface of the container, which can lead to cracks.

Therefore, an object of the present invention is to provide a method for manufacturing glass using the sol-gel method, which prevents cracks during aging and drying and facilitates the production of large glasses by improving the aging and drying method of wet gel. It's there to do.

[Means for resolving issues]

a! of glass produced by the sol-gel method of the present invention! ! The method of sending is
A liquid sol with a conventional glass component composition is prepared using metal alkoxide or fine particles of metal alkoxide and gold J1 oxide as main raw materials, and the liquid sol is gelled in an F71-shaped sealed container to produce a wet gel. After that, in the production of glass by drying and sintering the wet gel, the wet gel is aged and dried in a cavernous atmosphere of 1kl.

[Effect]

According to the present invention, during ripening and drying, the wet gel is placed under a 1F4 cotton cloth.
n IIk during aging, soft gel strength and! π
The shrinkage force during drying is not as strong and the load is reduced.

Therefore, cracks are less likely to occur in the wet gel, making it easier to manufacture large glasses.

〔Example〕

l) Commercially available ethyl millicate (S i (OEi),
) 132ρ, 0.0IN-IICβ108β, and 45 kg of ultrafine particle silica (trade name: Aerosil 0X50 (Degussa)) were mixed and 811
The above procedure was carried out for 3 hours to carry out the hydrolysis reaction of ethyl silicate and to prepare a sol in which ultrafine silica particles were dispersed to a certain degree. After this, in order to further improve the dispersibility, the dispersion liquid was irradiated with ultrasonic waves (combined with stirring) for 5 o'clock at 5 o'clock.
(In order to prevent the sol temperature from increasing due to radiation, the sol temperature was kept constant by a cooling device.

As a next step, the sol was subjected to centrifugation treatment (3,00 Orpm 1C) to remove semi-gelled jelly-like impurity-containing large particles and dust.
n) was added, and the sol was further purified by filtration.

Next, while stirring the sol, IN-ammonia water was added dropwise to adjust the pTI value to 3-0. After this, it is subjected to treatments such as recentrifugation and filtration, and the size is 30X30X20 (
cm) in a polypropylene container with 10ρ, 7.5J2
．． Six doses each of 5β and 2.5β were injected, the lids were closed, and the gels were formed in a closed state to prepare wet gels. The wet gel prepared here was dried for each injection fL1 using the following three methods. (1) The container was kept as it was, but the lid had a 5% porosity.

(2) A sponge with a thickness of I cm was placed under the wet gel, and the lid had a porosity of 5%.

(3) A 4 cm thick sponge was placed under the wet gel, and the lid had a 5% porosity.

These were put into a dryer and dried at 70@C. Table 1 shows the preparation status of the dried gel.

Table 1 Drying condition As shown in Table 1, it was difficult to produce a thick dry gel without the method of the present invention.

The dry gel thus obtained was placed in a sintering furnace and sintered by heating to obtain a transparent glass body at 1350@C. The size of these glasses is 15
X15X1.3 (am), 15X15X2.
8 (cm), same? , 15X 15X3.0 in 5j2
(cm), same 10.12 and 15X15X5. '3 (a
m), and the physical properties of the glass thus obtained were consistent with those of silica glass, including Vickers [Il', specific gravity, coefficient of thermal expansion, infrared absorption spectrum, near-infrared absorption spectrum, and refractive index. .

〔Effect of the invention〕

As described below, according to the method of the present invention, the generation of cracks during aging and drying can be suppressed, and large-sized glass can be easily produced.

Therefore, it is thought that the application will expand to various fields such as photomask substrates for IC, optical fiber 9 materials, and optics, as well as fields where quartz glass has been used up until now.

In addition, in one culm of sol preparation, Tis Ges Na,
Cas f, is Aρ% Tas Z rs Crs
By adding various elements such as, it is easy to manufacture various multi-component glasses and glasses other than filled glass.

that's all

Claims (1)

[Claims] (1) Using metal alkoxide or fine particles of metal alkoxide and metal oxide as main raw materials, prepare a liquid sol with the desired glass component composition, and gel the liquid sol in a sealed container of desired shape to produce a wet gel. A method for producing glass by a sol-gel method in which the wet gel is then dried and sintered, the method comprising aging and drying the wet gel on a spongy underlayment.