JPS62246826A - Production of glass - Google Patents

Abstract

PURPOSE:To enable sol homogeneous and excellent in dispersibility to produce in a short time and to enable the mass production of glass by directly irradiating ultrasonic wave for sol in the producing process of sol in the production of glass by a sol-gel process. CONSTITUTION:In the producing process of sol in the production of glass by a sol-gel process wherein alkylsilicate and ultrafine silica particles are used as a main raw material and liquid sol having the componental composition of the aimed glass is produced, and this sol is allowed to gel and thereafter dried and sintered, (A) after mixing the raw material, the dispersion of the ultrafine silica particles is preformed by using an immersion type ultrasonic wave vibrator, an ultrasonic wave homogenizer or the like, and directly irradiating ultrasonic wave vibration without permeating a medium such as a reaction vessel, and (B) the irradiation of ultrasonic wave is performed while stirring the dispersed soln. of this ultrafine silica particles. High-quality quartz glass can be mass-produced.

Description

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

[Conventional technology]

After gelling a sol prepared by mixing ultrafine silica into a hydrolyzed alkyl silicate solution using alkyl silicate and ultrafine silica as main raw materials,
When producing glass using the sol-gel method, which involves drying and sintering this, ultrasonic waves are indirectly applied from outside the mixing container in order to uniformly disperse the ultrafine silica particles mixed into the alkyl silicate hydrolyzed solution. It was done in a way that

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, since the ultrasonic irradiation was performed through the container, the ultrasonic wave was absorbed and reflected by the container, and it took a very long time to disperse the ultrafine silica particles, which decreased the dispersion efficiency. . Further, since the degree of absorption and reflection of ultrasonic waves depends on the material of the container, it is difficult to select the material of the container, and in some cases, it is necessary to use a rather expensive material. Therefore, the present invention aims to solve these problems.The purpose of the present invention is to create a system that can directly irradiate ultrasonic waves to the dispersion liquid using equipment equivalent to the conventional equipment, and also uses stirring. By doing so, it is possible to uniformly and efficiently disperse ultrafine silica particles in a hydrolyzed solution of alkyl silicate, and to provide a method for manufacturing glass using a sol-gel method that facilitates mass production. It's in the ro.

[Means for solving problems]

The method of the present invention involves preparing a liquid sol with a desired glass composition using alkyl silicate and ultrafine silica as main raw materials, gelling the sol, drying and sintering the sol.
The method for producing glass by the gel method is characterized by having the following treatment method during the sol preparation step.

a. After mixing the raw materials, the ultrafine silica particles are dispersed by directly irradiating ultrasonic waves using an immersion type ultrasonic vibrator, an ultrasonic homogenizer, etc. without using a medium such as a reaction container. b, When irradiating ultrasound at α,
According to the present invention, the ultrasonic waves are directly irradiated to the sol while stirring the ultrafine silica dispersion liquid, so that the absorption of the ultrasonic waves that occurs when the ultrasonic waves are irradiated indirectly through a container, Since there is no attenuation due to reflection, it is very efficient, and by using stirring in combination, a homogeneous sol with good dispersibility can be produced in a short time. Therefore, it becomes extremely easy to cope with mass production of glass. [Example] Commercially available ethyl silicate (Si (OEc)) 1
52A, (LOINHO 6108t and 45t of ultrafine silica (trade name: Aerosil oxso (Degussa)) were mixed at the same time, and stirred for 2 to 3 hours using a Dissilver (stirring and dispersing device) to perform a hydrolysis reaction of ethyl silicate and A sol in which fine particle silica was dispersed to some extent was prepared.The subsequent ultrasonic irradiation to improve the dispersion of ultrafine particle silica in the sol was performed using the following three methods on three batches of sols prepared in the same manner as described above. As an evaluation of the dispersion of ultrafine silica particles in the sol,
Using measurements of viscosity and particle size distribution, and based on conventional empirical data, ultrasonic irradiation was performed until the viscosity was 15 Cp and the average particle size [L08 μm or less].

■ Ultrasonic waves were irradiated directly from the outside of the sol-containing container.

■ An immersion type ultrasonic transducer was placed in the sol and ultrasonic waves were irradiated.

(2) An immersion type ultrasonic vibrator was placed in the sol, and the sol was irradiated with ultrasonic waves while stirring. This result shows that when comparing the time required to reach the above conditions (viscosity of 15cn or less, average particle size of 108μ or less), it was 20 hours, 8 hours, and 4 hours in the cases of ■, ■, and ■, respectively. .

Here, the reason that ■ was less efficient than ■ was because the dispersion was non-uniform and the dispersibility was poor in some areas.

As the next step, the sol is centrifuged at 1i11 (3000 rpm, 1
0 to 30-) were added. After this, the sol was further passed through to remove foreign substances. Then, while stirring the sol, [1
Drop 1N ammonia water and adjust the pH value to 3 to 6.
After stirring for 20 minutes, re-centrifuge 11 il! to remove gel particles generated during this process. (3000rpm,
10-50mm), re-filtered, size 36
6 each in x24 x 12 (cIn) polypropylene containers
0Of, 400 pieces in each batch (total 1,200 pieces) were added and gelatinized in a sealed state. After this, when the shrinkage starts, change the lid of the container to a specified one with holes for drying kW degree m section, put it in the dryer, and heat it up from room temperature to 5 m.
Heated to 60-80℃ at ℃/hr and kept at this temperature thereafter, increasing in size to 25±(L5)X (
A dry gel of 15±(L4)×((L5±(Ll) [m] was obtained.

These dried gels were put into a sintering furnace and heated and sintered using a predetermined heating method to obtain a transparent glass body at 1300 to 1450°C. The size of this glass is (18±[14)X
(11±[L3)X ((L!1±a, 05) [wound] and the superposition was 180±5[?].

The results of physical property analysis of the glass obtained as described above were completely consistent with fused silica glass, including Vickers hardness, specific gravity, coefficient of thermal expansion, infrared absorption spectrum, near-infrared absorption spectrum, and refractive index.

〔Effect of the invention〕

As described above, the quartz glass produced according to the present invention can be easily produced at a large loss, and high-quality products can be produced by purification during sol preparation.

As described above, in addition to having advantages such as lower cost than the fusion method, it is also possible to easily produce very high quality quartz glass, which has not been used until now.

We believe that it will find applications not only in the fields in which it has been used, but also in a variety of other fields, such as photomask substrates for engineering C and base materials for optical fibers. Also, At.

By mixing the specifications of Ti, Gel, Na, Mg, Li, To, etc. at the time of sol preparation, it is possible to produce high-quality glass with a component system that has various different characteristics.

that's all

Claims (1)

[Claims] (1) A method for producing glass by a sol-gel method in which a liquid sol with a desired glass component composition is prepared using alkyl silicate and ultrafine silica as main raw materials, the sol is gelled, and then dried and sintered. A method for producing glass, which comprises the following treatment method during the sol preparation step. a) After mixing the raw materials, the ultrafine silica particles are dispersed by directly applying ultrasonic vibrations using an immersion type ultrasonic vibrator, ultrasonic homogenizer, etc. without using a medium such as a reaction vessel. , b) in a, when irradiating the ultrasonic wave, the ultrafine silica dispersion is stirred;