JPH0570175A - Production of porous glass - Google Patents

Abstract

PURPOSE:To provide a method for producing porous glass, capable of controlling pore diameter of about >=0.05mum and having a sharp pore diameter distribution according to a sol-gel method. CONSTITUTION:Fine particles, composed of an organic polymer and having 0.05-10mum particle diameter are dispersed in a metallic alkoxide, which is hydrolyzed and then burned. Thereby, the pore quality of the resultant porous glass can be controlled with the particle diameter of the organic polymer to be dispersed in the metallic alkoxide. The pore diameter of the porous glass can be decreased with decreasing particle diameter of the organic polymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing porous glass whose pore size can be controlled.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a porous glass, there are a method of sintering fine glass powder, a method of mainly hydrolyzing a metal alkoxide (sol-gel method), a method of phase separation of glass and the like. Was known. However, it is difficult to obtain a porous glass obtained by sintering fine glass particles by a sintering method with a pore diameter of 1 μm or less.
The porous glass obtained by the phase separation method has a feature that the pore distribution is sharp, but it has a drawback that the composition and purity of the porous glass are limited.

Further, the porous glass obtained by the sol-gel method has cracks in the drying / sintering process, and it is difficult to control the pore diameter, and the pore distribution is smaller than that of the porous glass obtained by phase separation. Broad. However, it is considered that the porous glass occupies an important position as a method for obtaining the porous glass because of the wide selection of the composition of the porous glass and the high purity.

[0004]

In the sol-gel method, the pore distribution is broad, and the problem to be solved is that it is difficult to control the pore size.

[0005]

The present invention provides a method for producing a porous glass by the sol-gel method, in which the pore size can be controlled at a pore size of about 0.05 μm or more and the pore distribution is sharp. , Particle size consisting of organic polymer
It is characterized in that fine particles of 0.05 μm to 10 μm are dispersed in a metal alkoxide to hydrolyze the metal alkoxide, followed by firing.

Examples of the organic polymer in the present invention include methyl polymethacrylate (hereinafter abbreviated as PMMA), polystyrene, and MMA-divinylbenzene copolymer. The particle size of these organic polymers is 0.05 μm. ~
As the 10 μm fine particles, for example, a PMMA latex aqueous solution, a polystyrene aqueous solution, an MMA-divinylbenzene aqueous solution, or the like is used. When the particle size is less than 0.05 μm, the dispersibility is poor, and when the particle size exceeds 10 μm, the pore size obtained becomes large and existing materials exist.
In consideration of the hydrolysis of the metal alkoxide described later, the fine particles of the organic polymer are preferably in a state of coexistence with water, for example, the latex aqueous solution as described above.

Fine particles of such organic polymers are commercially available. As the metal alkoxide in the present invention, ethyl silicate (hereinafter abbreviated as TEOS), zirconium propoxide, aluminum propoxide and the like are used. The amount ratio of metal alkoxide to organic polymer is 2 to 20.

In the present invention, it is preferable to uniformly disperse fine particles of an organic polymer in the metal alkoxide in order to make the pore distribution uniform. Next, the metal alkoxide is hydrolyzed. The hydrolysis is usually carried out by heating a dispersion of the organic polymer fine particles in the metal alkoxide to 40 to 80 ° C., though it depends on the kind of the metal alkoxide used. A porous glass is obtained by drying after hydrolysis and then firing. The firing temperature is usually 5
It is 00-600 degreeC. Examples of the present invention will be described below.

[0009]

【Example】

Example 1 An aqueous latex solution of PMMA having a particle diameter of 1.2 μm (concentration: 11.1%) was added to 18.6 cc of nitric acid of 1.65 at a concentration of 1.65.
What added g was added to TEOS 22.4cc, and it stirred for 1 hour. Further, this was hydrolyzed in a constant temperature bath at 60 ° C. for 24 hours. Then, it was air-dried for about 3 days and fired at 600 ° C. for 24 hours to obtain a porous glass. The pore distribution measured by the mercury intrusion method and electron micrographs are shown in FIGS.

Example 2 PMMA latex aqueous solution having a particle size of 0.15 μm (concentration: 1
For 2.5%), a porous glass was obtained in the same manner as in Example 1. The pore size distribution of the obtained porous glass is shown in FIG.

[0011]

As described above, according to the present invention, a porous glass having a sharp pore distribution can be produced by the sol-gel method. Moreover, the pore size of the porous glass can be controlled by the particle size of the organic polymer dispersed in the metal alkoxide, and the smaller the particle size of the organic polymer, the smaller the pore size of the porous glass. it can.

[Brief description of drawings]

FIG. 1 is a diagram showing a pore distribution of a porous glass of Example 1 of the present invention obtained by using PMMA having a particle diameter of 1.2 μm.

FIG. 2 is a view showing an electron micrograph of the particle structure of the porous glass of Example 1 of the present invention.

FIG. 3 is a diagram showing the pore distribution of the porous glass of Example 2 of the present invention obtained by using PMMA having a particle size of 0.15 μm.

Claims (1)

[Claims] 1. A particle size of 0.05 μm to 1 composed of an organic polymer.
A method for producing a porous glass, characterized in that fine particles of 0 μm are dispersed in a metal alkoxide to hydrolyze the metal alkoxide, followed by firing.