JPH02277823A - Production of fiber or filmy product of compound with tetragonal tunnel structure represented by axga16+xti16-xo56 - Google Patents

Abstract

PURPOSE:To readily obtain a spinning dope easy in viscosity adjustment, excellent in stringiness, homogeneity and stability, also good in spinnability by adding raw material of specified composition to an aqueous solution of citric acid, etc., followed by dissolution and concentration. CONSTITUTION:Raw material with Ti (titanium alkoxide), Ga (nitrate) and A (carbonate) formulated so as to represent a composition of formula AxGa16+xTi16-xO56 (A is K, Rb or Cs; x is 0.5-2) is added to >=0.85 molar times of an aqueous solution of citric and/or tartaric acid (based on the total amount of the components A, Ti and Ga) and dissolved. The resultant solution is appropriately concentrated and put to spinning into fibrous or filmy product. The product is then baked at 1200-1500 deg.C to obtain the objective formed product of mixed system comprising (A) single or major phase of formula AxGa16+xTi16-xO56 and (B) a small amount of one or both of TiO2 (rutile) and beta-Ga2O3 (beta-gallia).

Description

Detailed Description of the Invention (Industrial Application Field) The present invention has a tetragonal tunnel structure and has a general formula A.
Ga1. +xTi, -xO,, (However, A:K, Rb
and Cs, x: 0.5 to 2).

(Prior art) General formula AxGa1. xTi1@−xOs, (however, A
: K.

Compounds having a tetragonal tunnel structure represented by Rb and Cs, x: 0.5 to 2) have excellent heat resistance and heat insulation properties, and are therefore useful as heat resistant and heat insulation materials, and are also used in plastics, metals, cement, etc. It is also used as a reinforcing material.

Conventionally, the flux method is known as a method for producing this compound (Japanese Patent Application No. 61-124095). This method uses an alkali molybdate as a flux, melts it at high temperature, and then slowly cools it. This is a method of growing fibrous single crystals through a precipitation reaction.

On the other hand, conventional methods for producing polycrystalline fibers such as alumina fibers and zirconia fibers include the precursor polymer method,
A slurry method, an inorganic salt method, a sol method, etc. are known, and may be applied to the production of the above-mentioned compounds. First, representative examples of these methods are as follows.

The precursor polymer method is a method in which ertel silicate is mixed into a viscous solution containing polyaluminoxane, an inorganic polymer having a main chain consisting of -Afl-0-, and the mixture is dry-spun and fired.

The slurry method is AQ20. Fine powder and small amount of M, CL6H2
0 and AΩ2 (○■]) as a binder component.

In this method, CQ2.2H20 is added to form a viscous slurry, which is then dry spun and fired.

The inorganic salt method is a method in which a water-soluble organic polymer such as polyethylene oxide or PVA is added to an aqueous solution of an aluminum salt, and water-soluble polysiloxane is further mixed to form a viscous liquid, which is blown out from a nozzle and then fired.

In the sol method, silica sol and ferrous acid are added to alumina sol containing ions such as HCOO and CH3COO to form a viscous liquid.
This method involves spinning and firing the fibers.

(Problems to be Solved by the Invention) However, both the flux method and the method for producing polycrystalline fibers have the following problems.

First, with the flux method, not only is it impossible to obtain long fibers, but also expensive flux is used.
There is a problem in that a recovery process is required, which increases manufacturing costs.

On the other hand, in the case of manufacturing polycrystalline fibers, the spinning solution is used to spin fibers, so the spinning stock solution is important, and the physical properties of the solution such as viscosity, spinnability, uniformity, and stability are important. The important factors are that the spinning stock solution is easy to produce and has excellent spinnability.

From this point of view, when the various methods described above are applied, firstly, although the precursor polymer method has high uniformity, it is difficult to control the manufacturing process for producing the spinning dope. Sol-
In the gel method, during the concentration stage, precipitation and turbidity occur, and the viscosity increases rapidly, making it difficult to control the concentration. Since the inorganic salt method uses a water-soluble organic polymer to provide the viscosity that gives the fiber form, the stock solution may lack stability, such as gelation during the preparation stage. In addition, the slurry method is a so-called heterogeneous system, and spinning JH! There are problems such as the viscosity, amount added, and dispersion state of the solid particles constituting the material, which subtly affect spinnability, making it difficult to control.

The present invention provides the general formula A, (Ga1a+xTiL, -,
○、.

(However, A: K, Rb and Cs, x: 0.5-2
) When producing fibers or membrane-like products of compounds having a square tunnel structure, it is possible to solve the problems of the spinning dope in the conventional method, to easily adjust the viscosity of the spinning dope, and to easily adjust the viscosity of the spinning dope. The object of the present invention is to provide a method that has excellent properties, uniformity, and stability, has good spinnability, and is easy to manufacture.

(Means for Solving the Problems) The present inventors have found that in order to achieve the above object, it is advantageous to apply a method for manufacturing polycrystalline fibers instead of a flux method that uses expensive flux. As a result of intensive research to solve the unique problems, we developed a viscous material suitable for spinning that uses a specific material as a composition raw material and adds it to a specific organic acid aqueous solution at a predetermined ratio to dissolve and concentrate it. They discovered that a thick liquid was obtained, and that the desired objective could be achieved by extruding, molding, and firing the liquid, and completed the present invention.

That is, AxGa1a+xTitG- according to the present invention.

The method for producing fibers or membranes of the compound represented by ○□ requires K, general formula A, )(Ga, G+xTi1.-xOS
When producing a compound having a tetragonal tunnel structure represented by G (A: K, Rb and C8, x: 0.5 to 2), titanium alkoxide is used as the Ti component of the raw material,
As the Ga component, use the nitrate of the component.

Using the carbonate of the component as the A component, each raw material blended in the composition ratio shown by the above general formula is mixed with citric acid in an amount of 0.85 times or more by mole based on the total amount of the A component, Ti component, and Ga component. In addition to an aqueous solution of acid and tartaric acid alone or a mixed organic acid, it is dissolved and concentrated to obtain a spinning solution.Then, this is spun to form a fibrous or film-like material, and then baked at 1200 to 1550 ° C. A X G a 1 t, +
A formation consisting of a single phase of xT x 16- xO5B or A xG a 1 G+8Ti□
A two-phase or three-phase mixed system in which G O5@ is the main produced phase and a small amount of K, TiX O□ (rutile) and β-Ga203 (β-Galia) or both are produced in small amounts. This method is characterized in that a molded article is obtained.

The present invention will be explained in detail below.

(Function) First, the general formula A) cGa, xTi□, -XO,
As raw materials for producing a compound having a composition represented by , and having a tetragonal tunnel structure, the following specific raw materials are used.

Titanium alkoxide is used as the Ti component. Examples of the titanium alkoxide include titanium tetraisopropoxide and titanium tetra-normal butoxide. In addition, titanium alkoxide is citric acid,
It reacts very easily with tartaric acid, giving a clear homogeneous solution, which can be converted into an oxide by calcination.

As the Ga component, its nitrate is used because of its availability and ease of handling.

Even if nitrates of K and Ga are added to the transparent solution thus obtained, the solution will not become non-uniform.

Further, GaTX may be dissolved in solid form with Fe, Cr, and AQ, and in this case, appropriate organic salts, inorganic salts, and alkoxides thereof can be used as raw materials.

Further, the carbonate is used as the component A, and when mixed with an organic acid aqueous solution (described later), it releases CO2 and becomes a transparent and uniform solution.

Each of these raw materials is added so as to have the composition ratio of the organic acid aqueous solution K, which is an individual or mixed organic acid of citric acid and tartaric acid, and is dissolved and concentrated to become a viscous liquid having stringiness.

In this case, the amount of the single or mixed organic acids of citric acid and tartaric acid needs to be 0.85 times or more of the total number of moles of component A, Ti component, and Ga component. If the amount is less than 0.85 times the mole, the resulting spinning stock solution will become non-uniform, will not exhibit spinnability, will be difficult to solidify, and will not be able to form into a fibrous or film-like product. The organic acid aqueous solution contains an A component, a Ti component, and a Ga component.
It is preferable to use water in an amount of 20 to 50 times the total number of moles of the components.

As a result, a transparent and uniform solution is obtained, and when this is heated and concentrated to a viscosity of about 1 to 100 poise, 90
A viscous liquid with stringiness is obtained at ~100°C. This liquid solidifies as the temperature decreases. Therefore, it is preferable to perform spinning at 90 to 100°C.

During spinning, long fibers are obtained by using a nozzle, and a membrane-like material is obtained by extruding from a slit. Further, it can be pressed through a thick diameter nozzle and burned and blown away with flame to produce ultra-fine short fibers.

In addition, the general formula A X G a 16 + X T
x 1@ −XO. The range of X in is 0.5≦X≦2
．． There is not much difference in the spinnability, viscosity, etc. of the spinning dope in the case of 0.

The obtained fibrous or film-like material is obtained by removing the 5th order component and having a
After heating in air at 100°C to decompose and remove organic substances, baking at 1200 to 1550°C yields the desired compound (fiber or film-like material) having a tetragonal tunnel structure. .

However, sintering will not be completed below 1200℃, and 155℃
If the temperature exceeds 0°C, it will start to melt, which is not preferable.

In addition, the above general formula Ax G 81G 4 X T 1
When x = 1.2 in 1g - 5g of Other than compounds with a crystalline tunnel structure, K, TiO2 (rutile) phases are present in large amounts, and X
is larger than 1 or 2, the more β-Ga2O3 (β-Ga2O3
- Gaul) phase increases. The optimal composition range of X is 1,0
<x≦1.5, but even if X is within the range of 0.5≦X≦2.0 shown in the above-mentioned general formula, the basic physical properties for its use are hardly affected.

(Example) Next, examples of the present invention will be shown.

This example uses the general formula AxGats4. xTlzs-)(
In Os6, this is the case where x=1.2, and this is an example of the case of synthesis using citric acid as the organic acid.

First, solution K was prepared by dissolving 28.6 g of citric acid in 50 mQ of distilled water, and 21.0 g of titanium tetraisopropoxide.
A transparent solution was obtained by adding g dropwise and stirring for about half a day.

Next, 0.41 g of potassium carbonate was gradually added to this solution, and the solution was stirred until it became transparent and uniform. All the above operations were performed at room temperature.

In addition to this K, 35,9 g of gallium nitrate nonahydrate (Ga(NO3)3 ・9 Hz O)
After stirring at room temperature for a while, the mixture was heated at 100° C. and concentrated until the viscosity reached 100 voids. This solution was a transparent, uniform, and viscous solution, and when it was left to cool, its viscosity gradually increased and it had good stringability.

Next, the material in an appropriate viscous state was extruded through a nozzle into a room under a dry atmosphere to obtain long fibers with a diameter of 5 to 100 tu. This fiber was colorless and transparent.

The obtained fibers were dried at 100°C overnight, then heat treated at 900°C for 2 hours, and then fired at 1300°C for 30 hours.

The obtained fibers had K, , Ga1. ．． 2TL0. ,,O
The fiber consisted of a single phase of gallotitanogallate having a tetragonal tunnel structure with a composition of .

Note that even when component A was replaced with K and Rb and Cs, similar single silk fibers were obtained.

]11 Rimoto's example is the general formula AX G a 1g +XT l z
g −X In O5B, x=1. This is the case of O, and this is an example of the case of synthesis using citric acid as the organic acid.

First, solution K in which 21.8 g of citric acid was dissolved in 50 mA of distilled water, and 14.8 g of titanium tetraisopropoxide.
A transparent solution was obtained by adding g dropwise and stirring for about half a day.

Next, 0.24 g of potassium carbonate was gradually added to this solution, and the mixture was stirred until it became transparent and homogeneous. All the above operations were performed at room temperature.

This K was further added with 24.6 g of gallium nitrate nonahydrate, and after stirring at room temperature for a while, it was heated at 100° C. and concentrated until the viscosity reached 100 poise. This solution was a transparent, uniform, and viscous solution, and when it was left to cool, its viscosity gradually increased and it had good stringability.

Next, the material in an appropriate viscous state was extruded through a nozzle into a dry atmosphere at room temperature to obtain long fibers with a diameter of 5 to 100 μm. This fiber was colorless and transparent.

The obtained fibers were dried at 100°C overnight, then heat treated at 900°C for 2 hours, and then fired at 1300°C for 30 hours.

The obtained fiber was KxGa11+xTi□8-XOo(
The fiber contained gallotitanogallate having a tetragonal tunnel structure having a composition of 1.1.2) and a very small amount of Tie2 (rutile).

By using the same raw material preparation method, K□, sG a17. .

When prepared to the composition of Tit+-s Os@, KxGa
□G4. A mixed phase fiber of gallotitanogalliumate and β-gallium with a composition of xTx, 0ss (X valve 1.2) was obtained.

Note that even when component A was replaced with K and Rb and Cs, similar mixed phase fibers were obtained.

This example is an example of synthesis using tartaric acid as the organic acid.

First, a solution of 14.2 g of tartaric acid dissolved in 50 mQ of distilled water was used as an organic acid aqueous solution, and then, as in Example 2, it was strained 1 time to prepare KX Ga1s+XTi□5-XO, (x:
1-0) with a tetragonal tunnel structure and a very small amount of TiO□ (rutile).
Long fibers containing the following were obtained.

In addition, in the case of tartaric acid, the relationship between compositional variation and synthetic sum was the same as in Examples 1 and 2.

Furthermore, similar fibers were obtained even when Rh and Cs were used instead of K for the A component.

(Effects of the Invention) As detailed above, according to the present invention, the viscosity of the spinning dope is controlled when producing fibers or membranes of the compound having a tetragonal tunnel structure represented by the above general formula. It is easy to adjust to the appropriate one, and it also has good stringability, uniformity,
It has excellent stability, good spinnability, and is easy to manufacture.

Therefore, it has the excellent effect that fibers or membranes having the desired composition can be obtained more easily and at a lower cost.

Claims (2)

[Claims] (1) General formula A_xGa_1_6_+_xTi_1_6
____xO_5_6 (However, A: K, Rb and Cs, x
:0.5 to 2) When producing a compound having a tetragonal tunnel structure, a titanium alkoxide is used as the Ti component of the raw material, a nitrate of the component is used as the Ga component,
Using the carbonate of the component as the A component, each raw material blended in the composition ratio shown by the above general formula is mixed with citric acid in an amount of 0.85 times or more by mole based on the total amount of the A component, Ti component, and Ga component. In addition to an aqueous solution of acid and tartaric acid alone or a mixed organic acid, it is dissolved and concentrated to obtain a spinning solution, which is then spun to form a fibrous or membrane-like material, and then baked at 1200 to 1550 ° C. A_xGa_1_6_+_xTi
A_xGa_1_6_+_xTi_ characterized by obtaining a formed body consisting of a single phase of _1_6_−_xO_5_6
1_6_-_xO_5_6 A method for producing a fiber or film-like material of the compound. (2) The phase generated by the calcination is A_xGa_1_
6_+_xTi_1_6_-_xO_5_6 is the main produced phase, and in addition, TiO_2 (rutile) and β-G
The method according to claim 1, which is a two-phase or three-phase mixed system in which one or both of a_2O_3 (β-galia) is produced in small amounts.