JPH10338570A - Fluoro-muscovite ceramics and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce ceramics capable of sintering at a low temp. of <=700 deg.C with conventional equipment and capable of contributing toward saving resources and energy. SOLUTION: At least one among kaolinite, pyrophyllite, natural muscovite and γ-alumina is blended with at least one among potassium silicofluoride, sodium silicofluoride, cryolite, potassium fluoride and sodium fluoride and the resultant blend is heated to 550-700 deg.C to obtain ceramics based on fluoro- muscovite or fluoro-paragonite crystals. Powder of the ceramics or power of the blend is blended with glassy powder contg. a muscovite component, sepiolite powder or titania powder and the resultant blend is compacted and sintered at <=600 deg.C to obtain the objective fluoro-muscovite combined ceramics fulfilling the functions of the constituents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ceramics used for various mechanical materials such as electronic parts and machines, and building materials such as walls and pavements, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, crystallized glass has been widely used for various mechanical materials such as electronic parts and machines, and building materials such as wall surfaces and pavements. This crystallized glass is obtained by depositing crystals by heat treatment on a molded product of molten glass, a molded product obtained by sintering glass particles, or the like. The method for producing crystallized glass requires specific techniques and equipment in at least melting at 1300 ° C. or more, and molding and crystallization steps such as a roll-out method and an integration method.

[0003]

SUMMARY OF THE INVENTION The present invention solves the conventional problems of requiring high-temperature heating and requiring a specific technique and equipment, and developing a new composition to reduce the conventional equipment by 700%.
An object of the present invention is to provide a ceramic which can be sintered at a temperature of ゜ C or less and can contribute to resource saving and energy saving, and a method for producing the ceramic.

[0004]

For this reason, the fluoro muscovite ceramics of the present invention is configured to precipitate fluoro muscovite. It should be noted that the fluoro muscovite may be a fluoro muscovite or a fluoro paragonite. Also, a fluoromica ceramic obtained by forming a titania thin film on the surface of a ceramic mainly composed of fluoromaskovite or fluoroparagonite may be used.

[0005] The process for producing a fluoromica ceramic according to the present invention comprises the steps of: preparing at least one of kaolinite, pyrophyllite, natural muscovite and γ-alumina, potassium fluorosilicate, sodium fluorosilicate, cryolite, potassium fluoride; And at least one of sodium fluoride and 55
This is a method of obtaining a ceramic mainly composed of fluorine muscovite or fluorine paragonite crystal by heating to 0 to 700 ° C. Further, a ceramic powder mainly composed of the obtained fluorine muscobite or fluorine paragonite crystal,
A vitreous powder containing a muscovite component may be blended and molded, and heated to 500 to 700 ° C. for sintering. Further, powder of a raw material composition mixture of fluorine muscovite or fluorine paragonite, or a ceramic powder mainly composed of these, and a sepiolite powder are blended and molded.
Sintering may be performed at a temperature of 00 ° C or less. Further, a powder of a raw material composition mixture of fluorine muscovite or fluorine paragonite, or a ceramic powder mainly composed of them, and a titania powder may be blended and molded, followed by sintering at 600 ° C. or less.

The present invention relates to a fluoromica ceramic obtained by precipitating fluoromica, which has a structure of a crystal of a fluoromica and a glass matrix.
As a result, ceramics similar to conventional crystallized glass can be formed by sintering at a low temperature. Further, at least one kind of kaolinite, pyrophyllite, natural muscovite and γ-alumina, and at least one kind of potassium silicofluoride, sodium silicofluoride, cryolite, potassium fluoride and sodium fluoride are blended, and 550 By heating to ゜ 700 ° C., ceramics mainly composed of fluorine muscovite or fluorine paragonite crystals can be obtained by low-temperature firing.

[0007] In addition, the obtained ceramics mainly composed of fluorine muscovite or fluorine paragonite crystals are powdered, or the powder of the raw material composition is sintered together with sepiolite or titania at a low temperature to maintain those functions. The resulting composite ceramic is obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (A)
The composition of the raw materials, (B) heat treatment and adjustment of the precursor, (C) molding of dense ceramics, (D) molding of composite ceramics, and (E) molding of titania thin film will be described separately.

(A) Raw material composition Fluorine muscovite composition [molar ratio K ₂ O · 3A suitable for chemical formula
_{l 2 O 3 · 6SiO 2 ·} 4F], blending each raw material molar ratio _{Na 2 O · 3Al 2 O 3} · 6SiO 2 · 4F] a reference component commensurate with paragonite composition [Formula. As the raw materials, kaolinite, pyrophyllite, pottery stone, potash or soda feldspar, nepheline, natural muscovite, montmorillonite, γ-alumina and the like are used, and the blending amount is determined based on the analysis value of each raw material. Here, at least one of these is used for the layer lattice of fluorine muscovite Al ₂ O
_This is for supplying ₃ and SiO ₂ components.

The fluorine component includes potassium fluoride (KF), sodium fluoride (NaF), potassium silicofluoride (K ₂ SiF ₆ ) and sodium silicofluoride (Na ₂ SiF).
F ₆ ), cryolite (Na ₃ AlF ₆ ) and the like are used. Here, at least one of these is blended in order to supply respective components such as K and Na of interlayer ions of fluorite muscovite and crystallization water F.

[0011] Fluorine muscovite belongs to fluoromica, and there are two types of fluorine muscovite [KAI ₂ (AlSi ₃ O ₁₀ ) F ₂ ] and fluorine paragonite [NaAI ₂ (AlSi ₃ O ₁₀ ) F ₂ ]. Fluorine mica is a layered crystal synthesized artificially and has a chemical formula of X _0.5
1.01.0 Y _{2.0 3.03.0} (Z ₄ O ₁₀ ) F ₂ . X is an interlayer ion and is a cation having a coordination number of 12, Z is a cation having a coordination number of 4 and forms a tetrahedron, and Y is a cation having a coordination number of 6 and forms an octahedron.

The mica structure is composed of an interlayer ion— [silicic acid tetrahedral—octahedral—silicic acid tetrahedral] as one molecular unit. In general, a typical example that can be melt-synthesized is fluorophlogopite [KMg ₃ (AlSi ₃ O ₁₀ ) F ₂ ] is known. Phlogopite system, octahedral positions, since the stable coordinated with Mg ₃ whereas can be easily synthesized by melting the formulation to meet the chemical formula, the white clouds maternally octahedral positions, Al ₂ And is one cavity, and cannot be synthesized by melting, but is synthesized by a solid phase reaction. These blends are prepared by using a powder having a mesh size of 250 mesh, preferably 325 mesh or less, wet with ethanol or the like, and uniformly mixing with a kneader.

(B) Heat Treatment and Precursor Adjustment Next, this blend was prepared in a wet state of about 1%, for 200 to 1 hour.
The granules are formed into particles at a pressure of 000 Kg / cm ² , placed in a refractory container, and heated in an electric furnace at 550 to 700 ° C. for 2 to 10 hours to carry out a solid phase reaction for deposition of muscovite crystals.

The solid phase reaction of fluoro muscovite is carried out by densely filling a raw material mixture of fine particles conforming to the chemical formula and heating the mixture, so that the surface atoms between the contact particles are bonded by thermal vibration below the melting temperature to form microcrystals. Fluorine muscovite is produced. Fluorine muscovite begins to form at 580 ° C. and peaks at 680 ° C.
It starts to be generated at 0 ° C and becomes maximum at 660 ° C. The solid phase reaction is performed for 2 to 10 hours, and a ceramic having a crystallization rate of 60 to 80% or more and a porosity of 10 to 20% is obtained.

Then, the ceramic is pulverized into a scaly powder of fluorine-containing mascovite or fluorine-containing paragonite. The powder is used as a precursor for producing dense ceramics. Hereinafter, the fluoromica ceramic is also referred to as a precursor, and the powder of the fluoromica ceramic is also referred to as a precursor powder. This powder has a use as a sintering binder which can compositely sinter other substances at a temperature of 500 to 650 ° C. in addition to the use as a fluorobiotite ceramic. Further, the precursor powder can be molded into an appropriate shape and used for a catalyst carrier, an oil-absorbing core and the like.

(C) Molding of Dense Ceramics Dense ceramics are obtained by blending 50% by weight or more of the precursor powder (under 200 mesh) and the balance of glass material (200 mesh or less). The glass material is a muscovite component, for example, a glass material containing K ₂ O, Na ₂ O, Al ₂ O ₃ , SiO ₂ , F, and a component Na ₂ O or a component that grows crystals as a mother glass of fluoromica. Materials containing K ₂ O and Al ₂ O ₃ · SiO ₂ , for example, Na ₂ O—CaO—SiO ₂ —Al ₂ O ₃ based soda-lime glass (bottle, float glass), B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ -based borosilicate glass and aluminum-based borosilicate glass can be used.

The addition of the glass substance is to increase the density by combining with the glass substance since the precursor becomes a porous body due to lack of glass matrix.

The mixture of the precursor powder and the glass material is homogeneously mixed in a mixer. The mixture was mixed with water or a conventional organic binder, and the mixture was press-molded (20).
0 to 500 kg / cm ² pressure) or extruder molding (10 to 200 kg / cm ² pressure).

After drying, the molded body is placed in an alumina sagger,
Bake in a heating furnace. Heating is performed at a heating rate of 100 / hour.
Perform at ~ 150 ° C and hold at 550-700 ° C for 2-5 hours. In this firing step, the precursor and the glass material are tightly bonded, and the microcrystals of the fluorobiotite in the precursor are homogeneously dispersed and grow.

If necessary, 0 to 5% by weight of B ₂ O ₃ ,
Body conditioner such as MgO and fluoride and 0 to 3% by weight of Fe
Color pigments such as ₂ O ₃ , NiO, Co ₂ O ₃ , Cr ₂ O ₃ , Mn ₂ O ₃ , and TiO ₂ may be appropriately added. B ₂ O _{3 as} a body conditioner is added for improving viscosity, MgO is used for improving thermal conductivity, and fluoride is added for replenishing crystal component fluorine.

The obtained ceramic contains 30 to 80% by weight of a crystal of fluorine muscovite or paragonite in a homogeneously dispersed state, having a specific gravity of 2.65 to 2.85 and a porosity of 0 to 0.
It has a mechanical strength of 0.3%, a bending strength of 400 kg / cm ² or more, and is peculiar to mica ceramics. It can be used for drilling, threading, grooving, etc. with ordinary steel tools.

(D) Molding of Composite Ceramics-Composite with Sepiolite The feature of composite ceramics is that a ceramic component containing fluorine muscovite as a crystal phase is used as a binding matrix and a functional inorganic material is sintered at a low temperature so as not to reduce its function. Things. First, a composite ceramic using sepiolite as a guest will be described.

Using either the precursor powder or the powder of the raw material composition mixture, add 30 to 70% by weight of sepiolite and the remainder a fluoromica substance, wet with ethanol or the like, and knead with a kneader to homogenize. Adjust the composition
After being molded under pressure at 0 to 200 kg / cm ² and dried, it is heated in a heating furnace at a heating rate of 50 to 80 ° C./hour, and 550 to 580
Hold at 3C for 3-5 hours and sinter.

According to the electron micrograph of the obtained composite ceramics, the porosity of sepiolite is maintained.
It was a porous ceramic having a bending strength of 150 to 250 kg / cm ² . Sepiolite is a double-chained silicate, which is fibrous fine crystal particles.
1.5 × 5.6 angstrom cross section), specific surface area 230
It is a porous mineral of up to 260 m ² / g and has a molecular action and has the ability to adsorb water, ammonia, acetaldehyde, etc. It loses its function. For this reason, it is possible to sinter 550
It sinters at ~ 580 ° C.

(D) Molding of Composite Ceramics-Compounding with Titania Precursor powder (under 300 mesh) is blended with ultrafine particles (50 nm or less) of titania (10 nm or less) by 10 to 15% by weight and wetted with ethanol or the like. A homogeneous mixture is prepared by kneading with a kneader, and pressure molding is performed at 50 to 200 kg / cm ² .
After drying, it is heated in a heating furnace at a heating rate of 50 to 80 ° C./hour and is sintered at 520 to 550 ° C. for 3 to 5 hours.

According to electron micrographs and X-ray diffraction measurements of the obtained ceramics, titania was dispersed in ultrafine particles, the crystal phase retained anatase, the flexural strength was 100 to 200 kg / cm ² , Showing a porosity of 25 to 40%,
It was not dismantled by immersion in water.

The ultrafine particles of titania (TiO ₂ ) exhibit photocatalysis by absorbing ultraviolet rays and being excited and polarized,
The crystal phase has a function in an anatase state. At 550 ° C. or higher, the crystal phase changes to rutile and the function is remarkably deteriorated. Therefore, by sintering the titania at 550 ° C. or lower, a composite ceramics having the function can be obtained.

(E) Titania Thin Film Formation Titanium suspension (anatase, particle size 20 nm or less, concentration 30-40)
%) On a substrate surface by a spin coater or the like, and after drying, baking at 450 to 480 ° C for 2 to 3 hours to 1.0 to 1.0%.
Ceramics with a 1.5 μm thin film baked can also be manufactured.

[0029]

According to the first aspect of the present invention, the fluoro muscovite ceramic is excellent as a ceramic having strength due to the precipitation of the fluoro muscovite crystal.
This results in a good precipitated crystal composition of the fluorine muscovite ceramics. In the third aspect, the photocatalytic ceramics having excellent elasticity and strength is obtained by the thin film layer of titania. Further, in claim 4 of the production method, a fluoro muscovite ceramic having an excellent crystallinity is obtained, in claim 5, a dense fluoro muscovite ceramic is obtained, and in claim 6, a sepiolite having excellent low-temperature sinterability is obtained. A composite fluorine muscovite ceramic with sepiolite having excellent porosity is obtained in claim 7, and a composite fluorine biotite ceramic with titania which is excellent in catalytic activity and low-temperature sinterability is obtained in claim 7. Muscovite ceramics are obtained,
According to the ninth aspect, a composite fluorine muscovite ceramic with titania which is excellent in catalytic activity and low-temperature sinterability is obtained.

[0030]

Examples 1 to 3 (Example 1) 77.7% by weight of kaolinite and 22.3% by weight of potassium silicofluoride were blended. Example 2 83.0% by weight of pyrophyllite and 17.0% by weight of potassium silicofluoride were blended. (Example 3) 37.0% by weight of γ-alumina and 36.5% by weight of silica
And 26.5% by weight of potassium silicofluoride. These formulas are based on fluorine muscovite [KAI ₂ (AlSi ₃ O ₁₀ )
F ₂ ].

The raw material is kaolinite (standard product of the Clay Science Society, composition SiO ₂ : 46.45% by weight, Al ₂ O ₃ : 39.52% by weight,
Loss on ignition 14.2% by weight], pyrophyllite [Standard product of the Clay Society of Japan, composition SiO ₂ : 66.3% by weight, Al ₂ O ₃ : 27.73% by weight, loss on ignition 5.57% by weight], γ-alumina [Al ₂ O ₃ · purity 4N,
Specific surface area BET 245 m ² g ⁻¹ , manufactured by Daimei Chemical Co., Ltd.], silica [SiO ₂ , average particle size 1.57 μm], and potassium silicofluoride [purity 2N, manufactured by Kanto Chemical Co., Ltd.] were used.

In each of the examples, the raw materials are crushed and used under 325 mesh. The mixture was dried at 120 ° C. for 2 hours, wetted with ethanol or the like, kneaded with a kneader, and press-molded with a press at 500 kg / cm ² to obtain a molded product (2
0 mmΦ, 5 mm thick disk). The molded body was placed on an alumina setter and charged in an electric furnace, and heated at a heating rate of 200 ° C./hour.
In Example 3, the temperature was maintained at 620 ° C. and the temperature was maintained at 620 ° C. for 15 hours to obtain a sintered body.

According to powder X-ray diffraction of the sintered body, muscovite (001) diffraction lines appeared around 8.6 ° (2θCuKα) in each of the examples, and were identified as fluorine muscovite. In addition, according to the electron micrograph (SEM × 10,000 times), flakes having a large aspect ratio were deposited in a card house structure, and the crystallinity was recognized to be about 65%. Example 1 has an apparent specific gravity of 2.35 and a porosity of 19.5%, and Example 2 has an apparent specific gravity of 2.4.
0, porosity 18.6%, Example 3 has apparent specific gravity 2.38, porosity 1
It was 9.1%.

[0034]

(Examples 4 and 5) (Example 4) The same raw material as in the previous example, pyrophyllite, was
7.4% by weight, potassium fluorosilicate [Na ₂ SiF ₆ purity 99.99
%, Manufactured by Kanto Chemical Co., Ltd.] 22.6% by weight. Example 5 The same raw material as in the previous example, pyrophyllite was added to 6
5.5% by weight and 34.5% by weight of sodium silicofluoride were blended. These formulations are compatible with paragonite [NaAI ₂ (AlSi ₃ O ₁₀ ) F ₂ ].

Each raw material uses powder under 325 mesh,
After drying, the mixture was wetted with ethanol or the like, and the mixture was molded under pressure at 500 kg / cm ^{2 using} a pressure machine to obtain a molded body (a disc having a diameter of 20 mm and a thickness of 5 mm). The molded body was placed on an alumina setter and charged in an electric furnace, and was heated at a heating rate of 200 ° C./hour. Example 4 was 650 ° C., and Example 5 was 700 ° C. at 2 ° C.
After holding for 0 hour, a sintered body was obtained.

According to powder X-ray diffraction of the sintered body, a paragonite (001) peak was observed at about 9.2 ° (2θCuKα) in each of the examples, and it was identified as paragonite. Also,
According to the electron micrograph (SEM × 10,000 times), paragonite flakes having a large aspect ratio were precipitated in a card house shape, and the crystallinity was recognized to be about 60% or more. Example 4 has an apparent specific gravity of 2.37 and a porosity of 25.1%.
The apparent specific gravity was 2.37 and the porosity was 18.2%.

[0037]

Example 6-Fluorine muscovite ceramics Precursor powder obtained by pulverizing the sintered body of Example 1 (under 200 mesh)
60% by weight, bottle glass [recycled product, composition SiO ₂ : 7
2.0% by weight, Al ₂ O ₃ : 4.0% by weight, B ₂ O ₃ : 15% by weight, CaO: 0.0
2% by weight, ZnO: 2.3% by weight, Na ₂ O: 5.0% by weight, F ₂ : 0.3% by weight] and 2% by weight of powder under 200 mesh, and wet-mixed with a ball mill. For 2 hours, and 0.5% solids PVA (10%
% Ethanol solution) and air-dried.
Molded under pressure at 0 kg / cm ² , molded body (105 × 105 × 6 mm plate)
I got

The molded body was placed on an alumina setter and charged in an electric furnace, and heated at a heating rate of 150 ° C./hour.
After maintaining at 700 ° C. for 2 hours, the mixture was allowed to cool to obtain a sintered body. Sintered a white fluorine muscovite ceramics, apparent specific gravity 2.51, porosity of 0.1%, a crystallinity of 68%, flexural a strength 460 kg / cm ^2, readily holes under water lubricated with cemented carbide drills Dawn processing was possible.

[0039]

Example 7-Fluorine paragonite ceramics Precursor powder obtained by pulverizing the sintered body of Example 5 (under 200 mesh)
60% by weight, float glass [recycled product, composition Si
O ₂ : 71.2% by weight, Al ₂ O ₃ : 2.6% by weight, CaO: 10.2% by weight, Na
₂ O: 14.2% by weight, K ₂ O: 1.0% by weight, Fe ₂ O ₃ : 0.22% by weight, Mg
O: 0.4 wt%, TiO _2: 0.08 wt%, SO _3: 0.1 wt% powder 38% by weight of, blended with 2 wt% powder sodium fluorosilicate (200 mesh under). This was wet-mixed in a ball mill, dried at 120 ° C. for 2 hours, wetted with PVA (10% ethanol solution) having a solid content of 0.5% by weight, air-dried, and then dried at 300 kg / cm ² with a press. Pressure molding was performed to obtain a molded body (a plate of 105 × 105 × 6 mm).

The molded body was placed on an alumina setter, charged into an electric furnace, and heated at a heating rate of 150 ° C./hour.
After maintaining at 700 ° C. for 2 hours, the mixture was allowed to cool to obtain a sintered body. Sintered is white paragonite Ceramics, apparent specific gravity 2.53, porosity 0% crystallinity 69%, a bending strength 520 kg / cm ^2, readily drilling under water lubricated with cemented carbide drills Processing was possible.

[0041]

Examples 8 to 12-Sepiolite Composite Ceramics Example 8 70% by weight of sepiolite powder and 30% by weight of fluorine paragonite powder were blended. (Example 9) 50% by weight of sepiolite powder and 50% by weight of fluorine paragonite powder were blended. (Example 10) 40% by weight of sepiolite powder and 60% by weight of fluorinated muscovite powder were blended. (Example 11) 70% by weight of sepiolite powder and 30% by weight of a powdery composition mixture of fluorinated muscovite were blended. (Example 12) 50% by weight of sepiolite powder and 50% by weight of a powder of a composition mixture of fluorinated paragonite were blended.

The raw materials were sepiolite [Aidplus SP (trade name) manufactured by Mizusawa Chemical Industry Co., Ltd.], the fluorinated muscovite powder of Example 6 (200 to 250 mesh), and the fluorinated paragonite powder of Example 7 (200 to 250 mesh). ), The composition powder of the composition of fluorine muscovite of Example 4 (under 200 mesh) and the composition powder of the composition of fluorine paragonite of Example 5 (under 200 mesh) were used.

After the formulations of Examples 8 to 12 were homogeneously mixed by a ball mill under wetness with ethanol, PVA (10%) was mixed.
% Ethanol solution) was added to the blend in an amount of 1 part by weight in terms of solid content, and the mixture was molded under pressure at 100 kg / cm ^{2 using a} pressure machine.
0 mmΦ, 7 mm thick disk). This molded body is
After drying at ゜ C for 3 hours, it was charged into an electric furnace, heated at a heating rate of 80 ° C / hour, and kept at 580 ° C for 2 hours to obtain a sintered body.

These sintered bodies were obtained by using an electron microscope photograph (SEM5
According to 000-fold), fibrous crystals of sepiolite is coupled while maintaining the porosity, bending strength Example 8 85 Kg / cm ^2, Example 9 is 105 Kg / cm ^2, the Example 10 150 kg / cm ^2, example 11 105 Kg / cm ^2, example 1
2 was 120 kg / cm ² .

The ceramics obtained in Examples 10 and 12 were bonded to the middle of a glass tube having an inner diameter of 50 mmΦ,
200 ml of test water in which NH3 10 PPM, Cl ^- 10 PPM, sesame oil 20 PPM emulsified with a cationic surfactant, and methylolene ₃ PPM were dissolved was poured into a glass tube from above and filtered. Example 10 permeated the test water in 5 minutes and Example 12 permeated the test water in 4 minutes, both became clear water, the sesame oil and methyl oleate emulsified were completely removed, NH ₃ and Cl ⁻
Both fell below 0.5 PPM.

[0046]

EXAMPLES 13～14- titania composite ceramic (Example 13) fine particles of titania (TiO ₂₎ [manufactured by Ishihara Sangyo Kaisha, Ltd.: ST-01 (trade name) particle size 7 nm] 20% by weight, of Example 1 78% by weight of a fluorinated muscovite powder (under 325 mesh) and a potassium fluorosilicate powder (325
2% by weight (under the mesh). (Example 14) 20% by weight of the same titania fine particles and 80% by weight of the powdered powder of the fluorinated muscovite composition of Example 3 (under 325 mesh) were blended.

After mixing the formulations of Examples 13 and 14 under a wet condition with ethanol in a ball mill for 3 hours until homogeneous.
One part by weight of PVA (10% ethanol solution) was added to the mixture in terms of solid content, and the mixture was press-molded at 150 kg / cm ^{2 using} a press to obtain a molded product (50 × 50 × 5 plate). Was. The molded body was placed on an alumina setter, charged in an electric furnace, heated at a heating rate of 80 ° C./hour, and kept at 520 ° C. for 1 hour to obtain a sintered body.

The sintered body of Example 13 had an apparent specific gravity of 2.51,
The porosity is 41% and the bending strength is 125 kg / cm ^{2. The} sintered body of Example 14 has an apparent specific gravity of 2.48, a porosity of 43%, and a bending strength of 128 kg.
/ Cm ² . Further, according to the powder X-ray diffraction, the TiO ₂ contained in both Examples 13 and 14 was identified as anatase.

Examples 13 and 14 were prepared by adding 0.2% aqueous ammonia solution.
It was immersed in 100 ml and irradiated with sunlight. The removal rate of ammonia was 83% in Example 13 and 85% in Example 14 after 3 hours, and reached 100% in both examples after 10 hours.

[0050]

[Example 15-Formation of titania thin film] Fluorine muscovite ceramics obtained in Example 6 (100 × 100 × 6 mm plate)
As a base ceramic, coated with an acid titania sol [Anatase sol STS-02 (trade name), manufactured by Ishihara Sangyo Co., Ltd., particle size 7 mm, 30% sol] by a doctor blade method, dried and dried at 420 ° C. for 3 hours. After heating for a period of time, a titanium film having a thickness of about 3 μm was formed. This film was strongly bonded to the base ceramics, and no cracks or the like were observed.

This thin film product was immersed in 500 ml of an aqueous solution containing 100 ppm of acetaldehyde, and irradiated with black light (ultraviolet ray amount: 1 mW / cm ² ). After 60 minutes the acetaldehyde had decreased to 3 ppm.

Claims (9)

[Claims] 1. A fluoro muscovite ceramic, which is obtained by depositing fluoro muscovite. 2. The fluorinated muscovite ceramic of claim 1, wherein fluorinated muscovite or fluorinated paragonite is precipitated. 3. A fluorine-biotite mica ceramic comprising a ceramic mainly composed of fluorine muscovite or fluorine paragonite and a thin film of titania formed on a surface of the ceramic. 4. A blend of at least one of kaolinite, pyrophyllite, natural muscovite and γ-alumina and at least one of potassium fluorosilicate, sodium fluorosilicate, cryolite, potassium fluoride and sodium fluoride. And heating to 550 to 700 ° C. to obtain a ceramic mainly composed of fluorine muscovite or fluorine paragonite crystals. 5. A ceramic powder mainly composed of a fluorinated muscovite or fluorinated paragonite crystal, and a vitreous powder containing a muscovite component are blended and molded.
A method for producing fluoro muscovite ceramics, which comprises sintering by heating to 700 ° C. 6. A porous fluorine muscovite ceramics characterized by blending a ceramic powder mainly composed of fluorine muscovite or fluorine paragonite and a sepiolite powder, and sintering at a temperature of 600 ° C. or less. Production method. 7. A porous fluorine muscovite ceramic characterized in that a powder of a raw material composition mixture of fluorine muscovite or fluorine paragonite and a sepiolite powder are blended, molded and sintered at 600 ° C. or lower. Manufacturing method. 8. A process for producing a fluoromica mica ceramic, comprising mixing a ceramic powder mainly composed of fluorine muscovite or fluorine paragonite and a titania powder, and sintering the mixture at 600 ° C. or lower. 9. A method for producing a fluoromica ceramic, comprising mixing a powder of a raw material composition mixture of fluorine muscovite or fluorine paragonite and a titania powder, followed by sintering at 600 ° C. or lower. .