JPS62143831A - Production of functional glass - Google Patents

Abstract

PURPOSE:To reduce moisture in glass and produce thick functional glass, by mixing a metal alkoxide with an aqueous solution of ions capable of imparting a desired function to the glass, hydrolyzing the alkoxide, extending and drying the resultant sol liquid and firing the dried sol. CONSTITUTION:A metal alkoxide to be a glass base material, e.g. ethyl silicate, etc., is mixed with an aqueous solution containing dissolved ions capable of imparting function to glass. As ion species, Nd<3+>, Tb<3+>, Ho<3+>, Er<3+>, Yb<3+> or Eu<3+> is used for laser emitting glass and Mn<2+> or UO2<2+> is used for luminous glass in addition to the above-mentioned ions. Fe<2+>, Fe<3+>, etc., are used for electrically conductive glass and heavy metal ion is used for colored glass. The mixture solution is then hydrolyzed while stirring and the sol solution after the reaction is extended into the form of a thin film. After the drying, plural sheets of the glass material in the form of thin film are laminated, fired and integrated. The desired functional glass, having a certain thickness and hardly causing strain or cracking can be produced by this method.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing a glass body by heating and sintering a porous gel obtained by a hydrolysis reaction of a metal alkoxide, and is particularly advantageous. This invention relates to a method of imparting some function to a glass body that is

(Prior art and its problems) Metal alkoxides (e.g. ethyl silicate-8L (OC2
Adding an aqueous solution containing a salt (metal ion) that colors the glass before, during or after the hydrolysis process of H5)4, etc.), drying and firing to obtain colored glass is described, for example, in JP-A No. 57. -11845 Publication, Japanese Unexamined Patent Publication No. 5
This method is known from, for example, Japanese Patent No. 8-185441. These methods are interesting as a means of developing a glass manufacturing method called the sol-gel method, and are characterized by the ability to easily obtain colored quartz glass, which is difficult to obtain using normal melting methods. It has the advantage of not requiring much high-temperature firing in the manufacturing process.

However, the conventional sol-gel method is not without drawbacks. One is that conventional methods have only proposed so-called colored glasses, in which metal ions with a coloring function are contained in the glass.Second, there are unavoidable circumstances in the sol-gel process, such as manufacturing problems. Moisture remains in the glass, and this moisture becomes a substance that interferes with the glass's ability to perform various functions.Furthermore, when it dries after hydrolysis, it tends to crack and distort, and the thickness (to a certain extent) For example, it is difficult to obtain a glass body with a thickness of 5 mm or more, which poses a serious obstacle in producing functional glass that requires a certain thickness.

(Problems to be Solved by the Invention) In view of the above-mentioned drawbacks of the sol-gel method, the present invention aims to reduce the amount of water remaining in the glass as much as possible, and to create a glass body with considerable thickness. The purpose of this paper is to propose a method for producing glass that fully demonstrates its performance.

(Specific Means for Solving the Problems) That is, the present invention involves stirring a mixed solution containing at least a metal alkoxide serving as a glass matrix and an aqueous solution dissolving ions that give functions to the glass, This method of manufacturing functional glass is characterized by spreading a sol solution into a thin film, drying it, then laminating a plurality of glass materials made into thin films and firing them into one piece.

To explain in more detail below, the functional glass referred to here includes not only colored glass and spectral filter glass, but also
Luminescent glass, laser oscillation glass, electrically conductive glass,
It refers to photosensitive glass, etc., and can be created by mixing silica glass or alumina quartz glass with active metal ions that give them functionality. The following are examples of ion species that should be mixed in various functional glasses: (1) Laser oscillation glass neodymium ions (Nd") terbium ions (Tb"+) holmium ions (l(o3+)) erbium ions (Er) ”) Interbium ion (yb”) Europium ion (E u 3”) (21 Luminescent glass In addition to the ion species listed in the laser oscillation glass above, transition metal ions such as manganese ion (yl n2 + ) Uranium oxide ion (U 022+ ), (3) hopping conduction type ions such as electrically conductive glass iron ions (Fe2+ and p e3+ ), vanadium ions (■4+ and V5+), and metal particles. (4) Colored glass (spectral filter glass) All of the heavy metal ions known to color glass (e.g. Cr” (green), Fe3+ (brown), Nd5+ (light purple)
, Er” (pink), etc.), and these ionic species often exist as oxides in glass.Of course, the present invention is not limited to the functions or ionic species described above. .

The metal alkoxide used as the glass matrix used in the present invention is a metal alkoxide of a metal oxide that can form a network structure on top of the glass structure, and one that is relatively easily available today is methyl silicate. (Si(OCH3
)4), ethyl silicate (Si(OC2Hs)4),
Propyl silicate (Si(OCx)-17)4), methyl borate (B(OCH3) s ), ethyl borate (B(
OC2H5) s ), methyl phosphate (P(OCH5)
s), ethyl phosphate (P(OC285)), and it is sufficient to use at least one selected from these metal alkoxides.However, in addition to these metal alkoxides, metal alkoxides used as an auxiliary Examples include aluminum alkoxide (Ae(OR)5: R is an alkyl group having 1 to 3 carbon atoms, titanium alkoxide (Ti(OR)4:
R is an alkyl group having 1 to 3 carbon atoms).

As mentioned above, there are various ions that give glass functions, but in the present invention, these active ions are
They are used in the form of dissolved aqueous solutions. In short, the aqueous solution only needs to have ionic species dissolved in it, but the ionic material can be mixed with water f8. g.

Of course, pure water is used to achieve this, but
There is no problem with using acidic aqueous solution or alkaline water injection at night. In the case of multi-active ion species, materials with active ionic species exist in the form of metals, salts, oxides, and hydroxides, so to dissolve them, in addition to pure water, diluted hydrochloric acid, diluted nitric acid, and diluted sulfuric acid are used. Using an aqueous acetic acid solution or an aqueous ammonium hydroxide solution is quick and practical as a means of obtaining an aqueous solution.Additionally, adding an acidic or alkaline aqueous solution can improve the concentration of metal alkoxide by adjusting the solution. It has a catalytic function that promotes hydrolysis reactions and is recommended.

Water is necessary as a solvent because it causes the hydrolysis reaction to occur. However, if the ionic species is added in the form of an aqueous solution, it may not be necessary to add it separately as water.

Further, assuming that the mixed liquid is in the form of an extremely thin film, the water is supplied from the air, so it may not even be necessary to add water to the mixed liquid at all. As mentioned above, the addition of an acid or alkaline solution as a solvent promotes the hydrolysis reaction, so it is preferable that it be present. Furthermore, when M(OCH5) x is used as the metal alkoxide, methyl alcohol is added as a component of the solvent, and when M(OC2H5) x is used, ethyl alcohol is added as a component of the solvent. can be said to be a preferred embodiment since it promotes the hydrolysis reaction.

Next, the appropriate proportions of each component in the liquid mixture to be hydrolyzed will be described. If silicon tetraalkoxide (Si
Assuming that 1 mole of (OR)4) is used, the metal ion as an ionic species will theoretically be 1 mole from IPPb.
Possible up to 0 mol. In addition, the amount of water (H2O) added can range from no addition to about 100 moles in practice, considering that moisture is supplied from water vapor in the atmosphere, but if it is too small, Since the hydrolysis reaction is delayed and the amount is too large, there are problems in the drying and sintering steps, so in practice, about 2 to 20 mol is appropriate. Acids such as hydrochloric acid and nitric acid, or alkaline solutions such as ammonium hydroxide, may be added in an appropriate amount, ranging from not being added at all, to about 10 moles at most, and adding more than that does not seem to make much sense. The lower alcohol added as a component of the solvent acts as a mediator to improve the compatibility between the metal alkoxide and the aqueous solution containing active ions, and as a result, it is recognized that it has the effect of completing the hydrolysis reaction in a short time. The amount of lower alcohols added is 02 to 1
Approximately 0 mol is appropriate, but even if it is not added at all, the practice of the present invention will not be hindered.

Since the hydrolysis reaction of the liquid mixture mixed at the above ratio will proceed only slowly if it is kept as it is, stirring and heating operations are performed to accelerate the reaction.

For stirring, there are methods such as using a stirring device using a magnet as a rotor or applying ultrasonic waves to the mixed liquid. The end point of the reaction is immediately after a sudden heat generation occurs, or when the mixture becomes transparent.
It can be easily recognized by the dramatic changes it exhibits.

In this way, a sol solution in which the hydrolysis reaction has been completed can be obtained. Interestingly, aqueous solutions containing active ionic species that impart functionality to glass can not only be added before and during hydrolysis, but can also be added additionally after the hydrolysis reaction is complete without any hindrance. be.

The obtained sol solution is spread into a thin film on any container or flat surface, left to dry in the air while keeping humidity changes small until it hardens to the extent that it can be handled with a bottle set, etc., and then heated from room temperature to 100°C. Allow to dry slowly over a few days until dry. At this point, a considerable amount of water and other unnecessary components will be removed. The thickness of the developed thin film is several 10
From micron, the upper limit is about 1 mm. In any case, homogeneous drying can be achieved by drying in a thin film state. Subsequently, a plurality of the obtained thin film bodies were laminated and heated for 10 to 600°C. From 600°C to 900°C, foaming phenomenon due to OH groups occurs, so the temperature was increased more slowly to prevent sintering. This is to obtain a thick glass body. O during firing
To prevent foaming due to H groups, it is possible to obtain a dense functional glass without bubbles by firing in a halogen element gas atmosphere such as chlorine gas, or by firing in a vacuum degassing atmosphere. It is.

(Function) The glass manufacturing method using the sol-gel method of the present invention can obtain functional glass, and can also obtain glass with a desired thickness and low water content. It is the body.

(Example 1) Ethyl silicate (Si(OC2Hs)4) 20 me
Prepare an aqueous solution of 10 g of ferric chloride ()"eCex, 6H20) dissolved in 30 me diluted hydrochloric acid diluted to 1/4 of 12N hydrochloric acid/water, and add 4 me is mixed with 20 me of ethyl silicate described above.Additionally, ethyl alcohol 3
The mixed solution obtained by adding me and 3me of water was stirred at room temperature using a stirring device using a magnetic rotor. Approximately 5
When stirred for a minute, the mixture generated heat and then became transparent, so stirring was stopped for a while and a yellow sol in which the hydrolysis reaction had progressed was obtained.Next, this sol was mixed with acrylic Spread it thinly on a resin plate to a thickness of about 0.5 mm, dry and harden it at room temperature for a few days while keeping humidity changes small, and then heat dry it for 3 days at 100°C in a heated open air oven. After cutting the glass into a size, about 20 sheets were laminated and the temperature was gradually raised to 1000°C to obtain a sintered glass body.The resulting glass body had a maximum thickness of 7.
mm, brownish colored quartz glass.

(Example 2) 3 g of metal neodymium (Nd) was added to 12N hydrochloric acid/water = 1
2.3 m of an aqueous solution obtained by dissolving 30 me of diluted hydrochloric acid
Mix e with 20m of ethyl silicate and add 3m of water.
When a mixed solution (light blue color) obtained by adding E and ethyl alcohol 3ME was stirred using a stone rotor for about 10 minutes, after a rapid heat generation, the solution became transparent and turned clear purple. The obtained sol body after the hydrolysis reaction was prepared in Example 1.
In exactly the same manner as above, spread out thinly, dry, laminate, and fire.

However, the inside of the firing furnace was made airtight, and the inside was vacuumed before firing. Maximum firing temperature is 1050℃
It is. The neodymium-containing quartz glass thus obtained is a light purple transparent glass with no bubbles inside. This glass exhibited a fluorescence spectrum similar to that of similar glasses made by plasma methods.

In addition, we conducted an oscillation experiment using xenon (Xe) flash lamp excitation, and the result was stable oscillation at a repetition rate of 10 Hz or more.
The heat load resistance characteristics were also excellent.

(Example 3) An aqueous solution obtained by dissolving 5 g of europium oxide (Eu203) in 20 me of nitric acid diluted with 10% by weight of water,
A mixed solution of 20 me of methyl silicate (Sl(OCH3)4) and 3 m e of methyl alcohol was stirred for about 5 minutes using a stirring rotor to form a transparent sol solution obtained by hydrolysis. Pink color) was spread thinly on an acrylic resin plate to a thickness of about Q, 4 mm, and cured into a gel-like form by drying in air at room temperature, and then heated and dried and laminated and fired in the same manner as in Example 1. It was 5m thick
A pink erbium-containing quartz glass of m was obtained. In order to confirm the luminescent properties of this glass, when it was irradiated with 355 nm ultraviolet rays and placed in a dark place, it was observed to emit orange visible light.

(Effects) The method for manufacturing functional glass of the present invention is as described above, and has the advantages that the conventional glass manufacturing method using the sol-gel method causes distortions and cracks when creating thick glass. On the other hand, according to the present invention, hardened thin films are laminated and sintered, which is less likely to cause distortion or cracking, and is suitable for use as functional glass such as laser oscillation glass or pseudo glass that requires a certain thickness. It is fully compatible with jewelry glass and the like, and by firing under vacuum suction, it is possible to prevent air bubbles from remaining inside the glass body. Furthermore, since the drying process is carried out in a thin film state, alcohol, water, residual acid components, etc., which are unnecessary as glass components, can be reduced as much as possible with low energy. This makes it possible to obtain a functional glass whose functions, such as the spectral properties of a spectral filter glass and the light emission properties of a light-emitting glass or a laser oscillation glass, are not inhibited.

Claims (2)

[Claims] (1) A mixed solution containing at least a metal alkoxide that serves as a glass matrix and an aqueous solution containing dissolved ions that give functions to the glass is stirred to spread the sol after the hydrolysis reaction into a thin film, and after drying, A method for manufacturing functional glass, characterized by laminating a plurality of thin glass materials and firing them into one piece. (2) The method for producing functional glass according to claim 1, wherein the firing is performed in a vacuum atmosphere.