JPH10273329A - Production of amorphous glass and drying vessel therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain formed gel materials constantly keeping uniform shapes without causing the cracking and deformation even by the volume contraction of the gel in drying stage by fitting conical recesses formed on the upper and lower faces of a gel to needle-shaped protrusions formed on the lids to close a cylindrical vessel and drying the gel while applying longitudinal compressive force by pressing a lid with a compression spring. SOLUTION: A sol 11 produced by the hydrolysis and polymerization of an organic and inorganic metal compound is poured into a cylindrical vessel 1 having the lower opening closed with a gelling lid 3 having a conical protrusion protruded in the vessel. The upper opening is closed by inserting a loosely- fitting lid 5 having a needle-shaped protrusion 5A at the center of the inside surface. The sol 11 is gelatinized to a gel 11 by maintaining at the room temperature or heating at about 50 deg.C. A compression spring 6 is placed on the loosely- fitting lid 5, a drying gel lid 4 is screwed on the spring and the vessel is heated at about 150 deg.C to dry the gel 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an amorphous glass body used for optics, semiconductor optics, electronics industry, science and engineering, and the like, and a drying container.

[0002]

2. Description of the Related Art In the synthesis of glass by the sol-gel method, a step of preparing a sol by stirring and mixing a metal alkoxide as a raw material, an alcohol as a solvent, water and a catalyst for a hydrolysis reaction, and subjecting the sol to a desired sol. The method comprises a step of forming a gel in a container, a drying step of removing a solvent from the gel to form a dry gel, and a firing step of making the dry gel nonporous.

In the above-mentioned drying step, the gel has been conventionally transferred to a drying container, but there has been a problem that the gel shrinks in volume during the drying and is cracked or distorted. For this reason, various shapes of drying containers or drying methods for preventing the gel from being cracked or distorted even when the gel contracts in volume have been proposed. For example, a method of drying using a hanging jig which holds the upper end of the gel in a free state and a method of drying while rotating while putting the gel in a cylindrical drying container have been developed.

In Japanese Patent Application Laid-Open No. 58-239, in order to improve the warpage of the gel, an enlarged portion having a width larger than the cylindrical portion is provided at the opening of the cylindrical container for drying, and the sol is supplied. A method is shown in which the gel is suspended at the enlarged portion of the opening of the container when the sol is gelled by filling up to the enlarged portion.

[0005]

However, in the method of drying while holding the upper end of the gel, the gel is unstable because the lower end of the gel shakes. On the other hand, in the method of drying while rotating the gel, a centrifugal force acts, so that a stress acts on the side surface of the gel, and the gel is brought into contact with one side and the shape of the side surface becomes unstable. For this reason, these methods have problems such as a small effect, a troublesome work, and a high device cost.

As disclosed in Japanese Patent Application Laid-Open No. 58-239, by providing an enlarged portion having a larger width than the cylindrical portion at the opening of the cylindrical container for drying, the gel can be enlarged at the opening of the container. In the hanging method, warpage can be prevented by hanging the gel vertically. However, since the gel is supported only on the upper part, when the container is taken out of the drying furnace after the drying step, if the container is subjected to vibration or the like, the gel shakes and hits the inner wall of the container, and there is a problem that the gel is damaged.

The present invention has been made in view of the above-mentioned problems, and has been made in view of the above. An amorphous glass which does not crack or distort even when the gel shrinks in the drying step, and can always obtain a gel having a constant shape. It is intended to provide a method for producing a body. Another object of the present invention is to provide a drying container used for drying a gel.

[0008]

To achieve the above object, the present invention provides a method for drying a gel obtained by hydrolyzing and polymerizing a solution of a metal organic and inorganic compound to obtain a dried gel. Providing a pair of lids provided with conical depressions at the upper and lower end surfaces of the gel, and a cylindrical container for housing the gel inside, and provided with needle-like projections at the center thereof,
These projections sandwich and support the conical depression of the gel from above and below, and at least one of the lids is provided with means for moving the gel vertically in accordance with the shrinkage of the gel. It is characterized by drying while supporting it.

The drying container according to the present invention has a cylindrical container having both ends opened in the longitudinal direction and accommodating a gel therein, and a needle-like projection contacting both end surfaces of the gel. A pair of lids detachably attached to both ends of the container, and at least one of the lids, which urges one of the lids to move in the longitudinal direction of the gel in accordance with shrinkage of the gel due to drying. And a biasing member.

When the solution of the organic and inorganic compounds of the metal is hydrolyzed and polymerized, a solvent, water and a catalyst for hydrolysis are mixed with the metal alkoxide and the like to form a sol. Can be.

The material of the cylindrical container and each lid used in the present invention is, for example, polytetrafluoroethylene, polypropylene, TPX (polymethylpentene) or PEEK (polyetheretherketone) whose inner surface is treated with silicone.

In the present invention, a sol is prepared by stirring and mixing a metal alkoxide or the like as a raw material, an alcohol as a solvent, water for hydrolyzing the metal alkoxide or the like, and a catalyst for promoting the hydrolysis reaction. Prepare. As the metal alkoxide, tetramethoxysilane, tetraethoxysilane, tetra-n-butoxytitanium, or the like can be used.As the alcohol, use methanol, ethanol, butanol, or the like, and as the catalyst, use hydrochloric acid, acetic acid, ammonia, piperazine, or the like. Can be.

The prepared sol is heated to room temperature or about 50 ° C. and gelled in a jelly state. At this time, by providing conical protrusions on the upper and lower end surfaces of the container for injecting the sol, conical depressions can be provided on the upper and lower end surfaces of the gel.

Next, the gel is dried. Usually, the temperature is gradually raised from room temperature and finally heated to around 150 ° C,
The gel is dried by evaporating the solvent and water contained in the gel. At this time, the gel contracts in volume due to the release of the solvent and water and the condensation polymerization reaction in the gel.
Thus, the length of the gel is shortened, but at least one of the lids moves up and down in accordance with the shrinkage of the gel, and the gel is constantly held between the needle-like projections of the lid from above and below to support the gel. Can be dried while being supported vertically in a cylindrical container.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As a metal alkoxide, 30 ml of tetramethyl silicate and 30 ml of tetraethyl silicate
ml, 12.4 ml of triethyl borate in ethanol 8
The mixture was mixed with 0 ml and 100 ml of water, and 25 ml of 0.01 N hydrochloric acid was added thereto, followed by stirring at room temperature for 1 hour. After this stirring, a mixture of 107.63 ml of a 1.25 mol / l aqueous solution of lead acetate and 15.35 ml of acetic acid as a metal component was added, and the mixture was further stirred at room temperature for 30 minutes to give sol 1
0 was prepared.

FIG. 1 shows a cylindrical container 1 into which the sol 10 is injected. The cylindrical container 1 is formed of polypropylene and has upper and lower ends opened, and the gelling lid 2 is detachable from the opening.
The gelling lid 2 is formed in a cap shape, has a screw 2A cut on the inner wall, and meshes with the screw 1A cut on the outer wall of the opening of the cylindrical container 1. Further, a conical projection 2B is provided at a central portion inside the gelling lid 2.

At the openings at the upper and lower ends of the cylindrical container 1, lids 3 A and 4 for dry gel shown in FIG. The drying container is formed by mounting the dry gel lid 3. A needle-like projection 3A is provided at a central portion inside the lid 3 for the dried gel. The length of the protrusion 3A is the same as the conical protrusion 2b of the gelling lid 2.
Is longer than the length. A needle-like projection 5A is provided at the center of the inside of the cylindrical container 1 and a drop lid 5 having an outer diameter that fits the inner diameter of the cylindrical container 1 is provided.
Can be inserted. The drop lid 5 can move up and down in the cylindrical container 1. The length of the projection 5A of the drop lid 5 is longer than the length of the conical projection 2B.

A compression spring 6 made of stainless steel is interposed between the drop lid 5 and the drying gel lid 4. Thus, the projection 5A of the drop lid 5 and the projection 3 of the lid 3
A, the tip of a conical dent formed at both ends of the gel is always held between the two, and the posture of the gel is maintained by fitting the outer peripheral surface of the drop lid 5 and the inner peripheral surface of the container 1. Has become.

Next, the sol 10 is poured into the cylindrical container 1. Prior to this injection, the opening at the lower end of the cylindrical container 1 is closed by the gelling lid 2, and after the sol is injected, the upper opening is closed by the gelling lid 2 (FIG. 1).
reference). Then, the sol 10 injected into the cylindrical container 1
Is heated to room temperature or about 50 ° C. to be gelled in a jelly state. At this time, vapors such as a solvent and water in the gel are released to the outside via upper and lower screw portions. FIG.
Shows a gel 11 formed by this, and has a conical projection 2A provided on the gelling lid 2 on the upper and lower end surfaces thereof.
Are formed, and conical depressions 12 and 13 are formed.

Next, the gelling lid 2 above the cylindrical container 1
Only and remove the lid 3 for the dried gel. Then, the cylindrical container 1 is turned over so that the remaining gel lid 2 faces upward, the gel lid 2 is removed, and the gel lid 2 is dropped from the opening of the cylindrical container 1, and the lid 5 is needle-shaped projection 5a. Is inserted downward, the compression spring 6 is inserted thereon, and then the lid 4 for the dried gel is screwed and closed, whereby the state shown in FIG. 3 is obtained.

The gel 11 is dried in this state. The temperature is gradually raised from room temperature and finally heated to about 150 ° C. to evaporate the solvent and water contained in the gel 11 and dry the gel. At this time, the volume of the gel 11 contracts due to the release of the solvent and water and the polycondensation reaction in the gel. As a result, the length of the gel 11 is shortened, but since the drop lid 5 is pressed downward by the compression spring 6, the gel 11 moves downward in accordance with the contraction of the gel 11, and the gel 11 is constantly removed from the dry gel lid 3. The projection 3A and the projection 5A of the drop lid 5 sandwich and support from above and below. Therefore, the gel 11 can be dried while being supported vertically in the cylindrical container 1, and a dried gel can be obtained.

Thereafter, the needle-like projections 3 on the lid 3 for the dried gel
A, and the gel 11 vertically supported in the cylindrical container 1 by the needle-like projections 5A of the drop lid 5 are put into a drying furnace together with the container, and heated to 80 ° C. At this time, the length of the compression spring 6 is 15 mm, and a load of 275 g is dropped on the gel 11 via the lid 5. As the drying proceeds, the entire length of the compression spring 6 increases in accordance with the shrinkage of the gel. At the end of the drying, the total length of the compression spring 6 becomes 65 mm, and a load of 25 g is dropped on the gel 11 via the lid 5. FIG. 4 shows a state where the drying is completed and the dried gel 14 is obtained.

The main dimensions and shapes of each part in this embodiment are as follows.・ Gel (before drying) diameter: φ15mm, length: 147mm ・ Dried gel diameter: φ8mm, length: 80mm ・ Cylindrical container diameter: φ18mm, length: 150mm ・ Compression spring diameter: φ15mm, natural length: 70m
m, spring constant: 5 g / mm

In this embodiment, the gel can be formed from the sol and the dried gel can be formed from the gel in the same cylindrical container. Therefore, it is not necessary to transfer the gel, and the gel may be damaged during the transfer. Can be prevented. In addition, since the gel is always supported vertically from above and below, a straight dry gel can be obtained.

[0025]

As described above, according to the method of the present invention, the gel can be prevented from being bent or damaged at the time of drying, and a linear dried gel can be produced. Further, according to the drying container of the present invention, the gel can always be reliably held from above and below in accordance with the shrinkage of the gel, so that the gel can be prevented from being damaged even by vibration or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a cylindrical container immediately after sol injection according to an embodiment.

FIG. 2 is a cross-sectional view of the cylindrical container immediately after the sol has gelled in the embodiment.

FIG. 3 is a cross-sectional view at the start of drying of a cylindrical container replaced with a lid for a dried gel.

FIG. 4 is a cross-sectional view of a state at the end of drying.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical container 2 Gelation lid 2B projection 3 Dry gel lid 3A projection 4 Dry gel lid 4A projection 5 Dropping lid 6 Compression spring 10 Sol 11 Gel 14 Dry gel

Claims (2)

[Claims] 1. A method of drying a gel obtained by hydrolyzing and polymerizing a solution of a metal organic and inorganic compound to obtain a dry gel, wherein a conical depression is provided on upper and lower end surfaces of the gel, In a cylindrical container housed inside, a pair of lids provided with needle-like projections at the center thereof are provided,
These projections sandwich and support the conical depression of the gel from above and below, and at least one of the lids is provided with means for moving the gel vertically in accordance with the shrinkage of the gel. Drying while supporting the glass body. 2. A cylindrical container for accommodating a gel therein, and a needle-like projection abutting on both end surfaces of the gel are formed at both ends in the longitudinal direction. A pair of lids detachably attached, and a biasing member provided on at least one of the lids and biasing one of the lids to move in the length direction of the gel in accordance with shrinkage of the gel accompanying drying. A drying container for use in a method for producing an amorphous glass body.