JPH05262514A - Mica sheet and its production - Google Patents

Abstract

PURPOSE:To provide a mica sheet excellent in mechanical strength and heat resistance without using a binder such as an organic cation and an organic adhesive. CONSTITUTION:The objective mica sheet is composed of a synthetic fluoromica, expressed by the following formula (I): alphaMF.betaLF.gamma(aMgF2.bMgO).deltaSiO2 [M is interlayer ion and denotes K<+> or K<+> and Ba<2+> and/or Pb<2+>; L is interlayer ion and denotes Na<+> or Li<+>; g and p each denote 0-2; (alpha+beta) is 0.1-2; gamma denotes 2-3.5; delta denotes 3-4; a and beach denote 0-1; (a+b) is 1] and obtained by heat- treating a mixture of talc with an alkali silicofluoride or an alkali fluoride and carrying out the ion exchange of interlayer ions in a synthetic swellable fluoromica.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mica sheet having high electric insulation, heat resistance and mechanical strength, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as an inorganic sheet composed of a layered silicate, for example, a film composed of sodium tetrasilicon mica is disclosed in JP-B-35-6874, which is disclosed in JP-A-55.
No. 142539 discloses a film made of glass and mica, JP-A No. 53-39318 discloses a film made of vermiculite, and JP-B No. 54-15043 discloses a film made of synthetic fluorine-containing montmorillonite. Each is listed.

However, such a conventional method has a drawback that bubbles are likely to be introduced into the film during the production of the film and the obtained film has insufficient mechanical strength. Further, Japanese Patent Publication No. 2-27282 discloses an inorganic-organic sheet made of a fluoromica-organic composite in which interlayer ions of a specific swelling fluoromica are exchanged with organic cations, and JP-A-60-155523 discloses a specific inorganic sheet. An inorganic sheet is described in which the interlayer ions of the swelling fluoromica are exchanged with organic cations, and then the interlayer organic cations are ion-exchanged with inorganic ions.

However, in the method for producing a mica sheet from such a swelling fluoromica, an organic cation such as alkylamine or aminoalcohol or an organic adhesive such as a silicone adhesive must be used as a binder. Since organic cations remain in the obtained mica sheet and an adhesive is contained, the purity and heat resistance are deteriorated, and it is impossible to obtain a mica sheet having sufficient performance capable of being used at high temperature for a long time.

On the other hand, when a sheet is produced from natural mica as a raw material, it is necessary to add an adhesive, and if the amount of addition is small, the mechanical strength of the obtained sheet is lowered and the mica sheet can be handled. Was difficult to obtain.

[0006]

It is an object of the present invention to use organic cations and binders such as organic adhesives,
The object is to provide a mica sheet having excellent heat resistance and mechanical strength.

[0007]

The first aspect of the present invention is to provide the following formula:
(I): αMF · βLF · γ (aMgF ₂ · bMgO) · δSiO ₂ (I) (wherein M is an interlayer ion and represents K ⁺ or K ⁺ and Ba ²⁺ and / or Pb ²⁺ . , L is an interlayer ion and represents Na ⁺ or Li ⁺ , α and β each represent 0 to 2 and α + β is 0.1 to 2, and γ represents 2 to 3.5. δ represents 3 to 4, and a and b are 0 to 1 respectively.
And a + b = 1), which is a mica sheet comprising an ion-exchanged synthetic swellable fluoromica complex.

In the second aspect of the present invention, a mixture of sodium silicofluoride or lithium silicofluoride and talc, or a mixture of sodium silicofluoride or lithium silicofluoride and sodium fluoride or lithium fluoride and talc is heated by an intercalation method. The following formula (II) obtained by the treatment: (α + β) LF · γ (aMgF ₂ · bMgO) · δSiO ₂ (II) (In the formula, L is an interlayer ion and represents Na ⁺ or Li ⁺ ; α + β) represents 0.1 to 2, and γ is 2 to 3.
5, δ represents 3 to 4, a and b each represent 0 to 1 and a + b = 1), and the synthetic swelling fluoromica and the potassium salt aqueous solution are mixed and stirred to form an interlayer. A method for producing the above mica sheet, characterized in that a synthetic swellable fluoromica composite having a composition according to claim 1 in which ions are ion-exchanged with K ⁺ is obtained, and the composite swellable fluoromica composite is dried into a sheet.

A third aspect of the present invention is a synthetic swellable fluoromica composite in which the synthetic swellable fluoromica represented by the formula (II) and an aqueous potassium salt solution are mixed and stirred, and interlayer ions are ion-exchanged to K ^+. Then, the synthetic swelling fluoromica complex and the barium salt and / or lead salt aqueous solution are mixed and stirred, and synthetic swelling in which interlayer ions are ion-exchanged with K ⁺ and Ba ²⁺ and / or Pb ²⁺ The method for producing a mica sheet is characterized in that a fluorinated mica complex is obtained and dried in a sheet form.

In a fourth aspect of the present invention, the synthetic swelling fluoromica represented by the formula (II) and an aqueous solution of barium salt and / or lead salt are mixed and stirred, and the interlayer ions are Ba ²⁺ and / or Pb ^2+.
To obtain a synthetic swellable fluoromica composite ion-exchanged with
Then, the synthetic swelling fluoromica complex and an aqueous potassium salt solution are mixed and stirred, and the interlayer ions are K ⁺ and Ba ²⁺ and / or
Alternatively, in the method for producing the mica sheet, a synthetic swellable fluoromica composite ion-exchanged with Pb ²⁺ is obtained and dried in a sheet form.

The present invention will be described in detail below. The synthetic swellable fluoromica represented by the formula (II) used in the present invention,
According to the method described in JP-A-2-149415, a mixture of sodium silicate fluoride or lithium silicofluoride (Na ₂ SiF ₆ , Li ₂ SiF ₆ ) and talc, or sodium silicofluoride or lithium silicofluoride and sodium fluoride or Lithium fluoride (Na
Unlike the conventional method, a mixture of F, LiF) and talc is heat-treated by an intercalation method. The heat treatment conditions are preferably 700 to 1000 ° C. and heating without melting the mixture. The synthetic swelling fluoromica produced by these production methods is 50 to 110 meq /
It exhibits a high methylene blue adsorption amount of 100 g (a simple method for measuring the cation exchange capacity) and can easily intercalate K ⁺ , Ba ²⁺ , Pb ^{2+ and the} like. To make a mica sheet without a binder, it is necessary to thin the synthetic mica, but the synthetic mica produced by the above method is fine particles, but has excellent sheet formability,
It can be easily made into a sheet.

The synthetic swelling fluoromica represented by the above formula (II) is a member of a sandwich type three-phase phyllosilicate in which two silica tetrahedral layers sandwich a magnesium octahedral layer, It is a clay mineral that has the ability to exchange cations in water and has the unique property of taking in water between layers and swelling. As a commercially available product, there is ME manufactured by Coop Chemical Co., Ltd.

The mica sheet of the present invention ion-exchanges Na ⁺ or Li ^+, which is an interlayer ion of the synthetic swelling fluoromica represented by the formula (II), with K ⁺ , or K ⁺ and Ba.
It can be produced by drying a synthetic swelling fluoromica complex obtained by ion exchange into ²⁺ and / or Pb ²⁺ into a sheet. Ion exchange of interlayer ions Na ⁺ or Li ⁺ into K ⁺ is carried out by a solution in which the concentration of the synthetic swelling fluoromica represented by the formula (II) is adjusted to 0.1 to 10% by weight, and potassium. It can be performed by a method of stirring after mixing the salt aqueous solution. At this time, an aqueous potassium salt solution may be added to the synthetic swellable fluoromica, or a synthetic swellable fluoromica may be added to the potassium salt aqueous solution.

As the potassium salt, potassium chloride, potassium hydroxide, potassium sulfate, potassium nitrate or the like can be used. As a stirring method, a normal stirrer can be used, but among them, a high-speed rotating machine such as a mixer is
It is preferable because the ion exchange reaction can be shortened.
Further, the liquid temperature may be raised during stirring to promote the ion exchange reaction.

As a method for ion-exchangeing interlayer ions Na ⁺ or Li ⁺ with K ⁺ for Ba ²⁺ and / or Pb ²⁺ , synthetic swelling in which the interlayer ions are ion-exchanged for K ⁺ is carried out as described above. Of fluorinated mica complex and barium salt and / or lead salt aqueous solution, followed by stirring, and the concentration of the synthetic swellable fluoromica represented by the formula (II) was adjusted to 0.1 to 10% by weight. Liquid, barium salt and /
Alternatively, after mixing the lead salt aqueous solution, the mixture is stirred and the interlayer ions are mixed with B
It can be carried out by a method in which a synthetic swellable fluoromica complex that is ion-exchanged with a ²⁺ and / or Pb ²⁺ is obtained, and then the synthetic swellable fluoromica complex is mixed with an aqueous potassium salt solution and then stirred. ..

As the barium salt, barium chloride, barium nitrate or the like can be used. As the lead salt, lead chloride, lead nitrate, lead silicofluoride, or the like can be used. The synthetic swellable fluoromica composite obtained by ion exchange in this way can obtain the mica sheet of the present invention by directly drying it into a sheet form, but since it contains an excess of salts, it is obtained. It is preferable to wash the synthetic swellable fluoromica composite, and more preferably, after washing, the synthetic swell uniformly dispersed in water using a known dispersing machine such as a strong shearing machine, an ultrasonic disperser, and a homogenizer. It is preferable to obtain a fluorinated mica complex sol and to dry the sol.

As a method for washing the synthetic swelling fluoromica complex, for example, a water washing method such as a filtration method, a centrifuge method and a gradient method can be used. In addition, in order to increase the cleaning efficiency,
You may use combining 2 or more types of these methods.
As a method for drying the synthetic swellable fluoromica composite thus obtained in a sheet form, the sol concentration is from 1 to 2
The product adjusted to 0% by weight is cast on a substrate having releasability, or blown and spread to form a 25 to 250
A method of peeling from the substrate after drying at ℃ is preferred.

For drying the sol, an infrared heater or the like may be used in order to shorten the drying time, or an excess solvent may be removed by a centrifugal separation method or a reduced pressure drying method, and then dried. Also, when continuously producing mica sheets,
A rotating drum or an endless belt can be used as the substrate.

[0019]

According to the present invention, since Na ⁺ or Li ^+, which is an interlayer ion of synthetic swelling fluoromica, is ion-exchanged with K ⁺ , it is extremely fine and has a very large sheet-forming ability. It can be made into a sheet. Therefore, in the present invention, a sheet having high heat resistance and mechanical strength can be obtained without using an organic material such as an adhesive or a binder. In addition, some of the interlayer ions of the synthetic swelling fluoromica ion-exchanged with K ⁺ are further converted into Ba ²⁺ and Pb ^2+.
The ion-exchanged product has a further increased mechanical strength, and an extremely thin foil that can withstand handling can be obtained.

[0020]

【Example】

Example 1 20.0 g of swelling fluoromica (ME manufactured by Coop Chemical Co., methylene blue adsorption amount: 80 meq / 100 g) was added to pure water 9
In addition to 80 ml, the mixture was allowed to stand overnight to obtain 1000 ml of a 2% swelling fluoromica dispersion. To this dispersion, 75 ml of a 15% KCl aqueous solution was added, and the mixture was stirred at room temperature for 3 hours using a stirrer to obtain an ion exchange product A in which most of the Na ⁺ of the interlayer ions were replaced with K ⁺ .

This ion exchange material A was subjected to filtration to obtain 50
It was washed with 00 ml of distilled water to obtain a cake-shaped ion exchange product A, which was dispersed in water to prepare a 5% sol. Next, this sol is spread on a stainless steel plate (SUS304) to a thickness of 10 mm and dried at 120 ° C. using a dryer.
And dried for 2 hours to obtain a mica sheet A having a thickness of 0.5 mm. Table 1 shows the component analysis results of the obtained mica sheet A. Next, with respect to the obtained mica sheet A, the weight change of the mica sheet was measured using a differential thermal analyzer.
As a result, no change in weight was observed up to 850 ° C. The following mechanical strength and hygroscopicity measurement tests were conducted. The results are shown in Table 2.

Mechanical Strength Measurement Test In accordance with the method specified in JIS-Z-1702, the tensile strength of the mica sheet was measured at room temperature using an Instron type tensile tester. Hygroscopicity test The dried mica sheet was allowed to stand in the atmosphere having a humidity of 80% for 24 hours, and the amount of moisture absorption was measured.

Example 2 The ion exchange product A obtained in Example 1 was washed with distilled water, and then 35 ml of a 15% barium chloride aqueous solution was added.
Using a stirrer, the mixture was slowly stirred at room temperature for 3 hours to obtain an ion exchange product B. In this ion-exchange material B, most of the interlayer ions Na ⁺ contained in the swelling fluoromica are K ^+
Was replaced with Ba ²⁺ . This ion exchange material B was filtered, spread and dried in the same manner as in Example 1 to obtain a mica sheet B. Table 1 shows the component analysis results of the obtained mica sheet B. The heat resistance of the obtained mica sheet B was evaluated in the same manner as in Example 1. As a result, 85
No change in weight was observed up to 0 ° C. Example 1
A measurement test of mechanical strength and hygroscopicity was conducted in the same manner as in. The results are shown in Table 2.

Example 3 The ion-exchange product A obtained in Example 1 was washed with distilled water, 45 ml of a 15% aqueous solution of lead chloride was further added, and the mixture was slowly stirred at room temperature for 3 hours with a stirrer. Exchange C
Got In this ion exchange material C, most of the inter-layer ions Na ⁺ contained in the swelling fluoromica are K ⁺ and Pb.
It was replaced by ²⁺ . This ion exchange product C was used in Example 1
Mica sheet C was obtained by filtering, spreading and drying in the same manner as. Table 1 shows the results of component analysis of the obtained mica sheet C. Regarding the obtained mica sheet C, Example 1
The heat resistance was evaluated in the same manner as. As a result, no change in weight was observed up to 850 ° C. Further, in the same manner as in Example 1, mechanical strength and hygroscopicity measurement tests were conducted. The results are shown in Table 2.

[0025]

[Table 1]

[0026]

[Table 2]

(Evaluation) As is apparent from Table 2, the tensile strength is 70 kg / cm ² or more for the mica sheet A and 90 kg / cm ² or more for the mica sheets B and C, and the moisture absorption amount is 1%. In the heat resistance evaluation, no weight change was observed up to 850 ° C., and all mica sheets showed excellent results.

[Procedure amendment]

[Submission date] February 19, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Mica sheet and method for producing the same

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mica sheet having high electric insulation, heat resistance and mechanical strength, and a method for producing the same.

[0002]

Conventionally, the inorganic sheet comprising a layered silicate, a film made of Japanese Patent Publication 35-6874 Patent sodium tetrasilisic mica in Japanese For example, JP-55-
No. 142539 discloses a film made of glass and mica, JP-A No. 53-39318 discloses a film made of vermiculite, and JP-B No. 54-15043 discloses a film made of synthetic fluorine-containing montmorillonite . Each is listed.

However, such a conventional method has drawbacks in that air bubbles easily enter the film during the production of the film and the obtained film has insufficient mechanical strength. Therefore, in order to increase the mechanical strength,
Organic adhesive such as silicone adhesive is used as an inder
Had to do. Further, Japanese Patent Publication No. 2-27282 discloses an inorganic-organic sheet made of a fluoromica-organic composite in which interlayer ions of a specific swelling fluoromica are exchanged with organic cations, and JP-A-60-155523 discloses a specific inorganic sheet. An inorganic sheet in which interlayer ions of swelling fluoromica are exchanged with organic cations and then the organic cations between the layers are exchanged with inorganic ions is disclosed in JP-A-61-83618.
Interstitial ion is a mixed ion of Na ⁺ and K ⁺ and has free swelling property.
Is it an inorganic gel containing a special free-swelling fluoromica?
And an inorganic film formed from
No. 619 discloses that interlayer ions have an ion index of 1.25.
Described above are inorganic films that are inorganic cations
It

However, the above-mentioned inorganic film is
Both use limited swelling mica as the starting material,
The intercalation ions of moist mica react with the organic cations in advance.
And then add organic cations to K ions and other
It is manufactured by a method of substituting with an inorganic cation. others
Therefore, the obtained mica sheet contains
Since organic cations such as alcohols remain, the purity is
It was deteriorated and a high-purity mica sheet was not obtained. Furthermore
In addition, the residual organic matter decomposes when exposed to high temperatures.
The heat resistance of the sheet decreases and it can be used at high temperature for a long time.
No mica sheet that could be obtained was obtained.

On the other hand, even if the natural mica as a raw material for producing the sheet over preparative requires the addition of an adhesive, the mechanical strength of the sheet obtained and the amount added is less is reduced, withstand handling It was difficult to obtain a mica sheet.

[0006]

It is an object of the present invention to use organic cations and binders such as organic adhesives,
The object is to provide a mica sheet having excellent heat resistance and mechanical strength.

[0007]

The first aspect of the present invention is talc.
And alkali silicofluoride or a mixture of alkali fluorides
Of synthetic swelling fluoromica obtained by heat treatment
On the obtained by ion exchange, the following formula (I): in _{αMF · βLF · γ (aMgF 2} · bMgO) · δSiO 2 (I) ( wherein, M is a layer between the ion, K ⁺ or K ⁺ with represents Ba ²⁺ and / or Pb ^2+, L is a layer between the ion, Na ⁺ or L
It represents i ^+, represent α and β Waso respectively 0-2, and α
+ Β is 0 . Is 1 to 2, gamma represents 2 to 3.5, [delta] is
3-4 represent, represent a and b Waso respectively 0-1, and a mica sheet characterized by consisting of synthetic fluorinated mica represented by a + b = 1).

In the second aspect of the present invention, a mixture of sodium silicofluoride or lithium silicofluoride and talc, or a mixture of sodium silicofluoride or lithium silicofluoride and sodium fluoride or lithium fluoride and talc is heated by an intercalation method. process to obtained the following formula (II): (α + β ) LF · γ (aMgF 2 · bMgO) · δSiO 2 (II) ( wherein, L is a layer between the ion represents Na ⁺ or Li ^+,
α and β each represent 0 to 2, and α + β is 0 . 1
Represents to 2, gamma represents 2 to 3.5, [delta] represents 3-4, represent a and b Waso respectively 0-1, and a + b = 1
Synthetic swellable fluorinated mica and potassium salt aqueous solution mixture was stirred represented by a is), characterized in that the interlayer ions give the ion exchanged set formed of synthetic fluorine mica K ^+, this is dried into a sheet And a method for producing the mica sheet.

A third aspect of the present invention is a synthetic fluorine cloud in which the synthetic swelling fluoromica represented by the formula (II) and an aqueous potassium salt solution are mixed and stirred, and interlayer ions are ion-exchanged to K ^+.
Mother , and then the synthetic fluoromica and barium salt and / or
Alternatively, the lead salt aqueous solution is mixed and stirred, and the interlayer ions are K ⁺ and B.
Synthetic fluorine cloud ion-exchanged for a ²⁺ and / or Pb ²⁺
The method for producing a mica sheet is characterized by obtaining a mother and drying the mother into a sheet.

In a fourth aspect of the present invention, the synthetic swelling fluoromica represented by the formula (II) and an aqueous solution of barium salt and / or lead salt are mixed and stirred, and the interlayer ions are Ba ²⁺ and / or Pb ^2+.
Obtaining a synthetic fluorine mica ion exchange, then, the case
The method is characterized in that synthetic ^fluoromica and an aqueous potassium salt solution are mixed and stirred to obtain a synthetic fluoromica in which interlayer ions are ion-exchanged with K ⁺ and Ba ²⁺ and / or Pb ²⁺ , and the sheet is dried. The method for producing the mica sheet described above.

The present invention will be described in detail below. The synthetic swellable fluoromica represented by the formula (II) used in the present invention,
According to the method described in JP-A-2-149415, a mixture of sodium silicate fluoride or lithium silicofluoride (Na ₂ SiF ₆ , Li ₂ SiF ₆ ) and talc, or sodium silicofluoride or lithium silicofluoride and sodium fluoride or Lithium fluoride (Na
Unlike the conventional method, a mixture of F, LiF) and talc is heat-treated by an intercalation method. The heat treatment conditions are preferably 700 to 1000 ° C. and heating without melting the mixture. The synthetic swelling fluoromica produced by these production methods is 50 to 110 meq /
It exhibits a high methylene blue adsorption amount of 100 g (a simple method for measuring the cation exchange capacity) and can easily intercalate K ⁺ , Ba ²⁺ , Pb ^{2+ and the} like. To make a mica sheet without a binder, it is necessary to make synthetic mica a thin layer.
Although synthetic fluoromica is fine particles, it has excellent sheet forming properties and can be easily formed into a sheet.

The synthetic swelling fluoromica represented by the above formula (II) is a member of a sandwich type three-phase phyllosilicate in which two silica tetrahedral layers sandwich a magnesium octahedral layer, It is a clay mineral that has the ability to exchange cations in water and has the unique property of taking in water between layers and swelling. As a commercially available product, there is ME manufactured by Coop Chemical Co., Ltd.

The mica sheet of the present invention ion-exchanges Na ⁺ or Li ^+, which is an interlayer ion of the synthetic swelling fluoromica represented by the formula (II), with K ⁺ , or K ⁺ and Ba.
Synthetic fluoride obtained by ion-exchange with ²⁺ and / or Pb ²⁺
It can be manufactured by drying mica into a sheet.
Ion exchange of interlayer ions Na ⁺ or Li ⁺ into K ⁺ is carried out by a solution in which the concentration of the synthetic swelling fluoromica represented by the formula (II) is adjusted to 0.1 to 10% by weight, and potassium. It can be performed by a method of stirring after mixing the salt aqueous solution. At this time, an aqueous potassium salt solution may be added to the synthetic swellable fluoromica, or a synthetic swellable fluoromica may be added to the potassium salt aqueous solution.

As the potassium salt, potassium chloride, potassium hydroxide, potassium sulfate, potassium nitrate or the like can be used. As a stirring method, a normal stirrer can be used, but among them, a high-speed rotating machine such as a mixer is
It is preferable because the ion exchange reaction can be shortened.
Further, the liquid temperature may be raised during stirring to promote the ion exchange reaction.

As a method for ion-exchange of interlayer ions Na ⁺ or Li ⁺ to K ⁺ and Ba ²⁺ and / or Pb ²⁺ , synthetic fluorine obtained by ion-exchange of interlayer ions to K ⁺ is carried out as described above. A method in which mica and a barium salt and / or lead salt aqueous solution are mixed and then stirred, a liquid in which the concentration of the synthetic swelling fluoromica represented by the formula (II) is adjusted to 0.1 to 10% by weight, and barium Salt and /
Alternatively, after mixing the lead salt aqueous solution, the mixture is stirred and the interlayer ions are mixed with B
This can be carried out by a method in which a synthetic fluoromica ion-exchanged with a ²⁺ and / or Pb ²⁺ is obtained, and then the synthetic fluoromica and the potassium salt aqueous solution are mixed and then stirred.

As the barium salt, barium chloride, barium nitrate or the like can be used. As the lead salt, lead chloride, lead nitrate, lead silicofluoride, or the like can be used. The synthetic fluoromica thus obtained by ion exchange can be obtained as it is by drying it into a sheet to obtain the mica sheet of the present invention, but since it contains an excess of salts, the synthetic fluoromica thus obtained is obtained. Is more preferably washed, more preferably, after washing, using a known shearing machine such as a strong shearing machine, an ultrasonic disperser, a homogenizer, to obtain a synthetic fluoromica sol uniformly dispersed in water, the sol preferably it dry.

As a method for washing the synthetic fluorine mica , for example, a water washing method such as a filtration method, a centrifugal method, a gradient method or the like can be used. Further, in order to enhance the cleaning efficiency, two or more of these methods may be used in combination. Synthetic fluorine mica thus obtained as a way to dry sheeting, a material obtained by adjusting the sol concentration 1 to 20% by weight,
A method is preferred in which it is cast on a releasable substrate, or it is sprayed and spread, dried at 25 to 250 ° C., and then peeled from the substrate.

[0018] Drying of the sol, may be used an infrared heater or the like in order to shorten the drying time, using a centrifugal separation method or a vacuum drying method, after removing the excess solvent, may be dried. Also, when continuously producing mica sheets,
A rotating drum or an endless belt can be used as the substrate.

[0019]

The synthetic swelling mica used in the present invention is
Luk and alkali fluoride or a mixture of alkali fluoride
Since it is obtained by heating the compound, it is synthesized by the melting method etc.
Better dispersibility in water than swellable mica
Therefore, Na ⁺ and Li ⁺ of interlayer ions can be easily converted into K ⁺ and B.
a2 ⁺ , Pb2 ^+, etc. can be intercalated, and the intercalated synthetic fluoromica
Since the particles are fine particles, they have extremely large sheet forming ability and
It has the feature that it can be easily made into a sheet. Therefore, in the present invention, without using organic materials such as adhesives and binders,
It is possible to obtain a sheet having heat resistance and high mechanical strength. Further, a part of the interlayer ions of the synthetic swelling fluoromica ion-exchanged with K ⁺ is further ion-exchanged with Ba ²⁺ or Pb ²⁺ , the mechanical strength is further increased, and it can withstand handling sufficiently. A very thin foil can be obtained.

[0020]

Example 1 Synthetic swelling fluoromica (ME manufactured by Corp Chemical Co., Ltd.,
20.0 g of methylene blue adsorption amount: 80 meq / 100 g) was added to 980 ml of pure water and left overnight to obtain 1000 ml of a 2% synthetic swelling fluoromica dispersion. 15% K in this dispersion
75 ml of an aqueous Cl solution was added, and the mixture was stirred at room temperature for 3 hours using a stirrer to obtain a synthetic fluoromica A in which most of the intercalation ions Na ⁺ were replaced with K ⁺ .

This synthetic fluoromica A was filtered to obtain 5
Cake-like synthetic fluoromica washed with 000 ml of distilled water
A was obtained, and this was dispersed in water to prepare a 5% sol.
Next, this sol was spread on a stainless steel plate (SUS304) to a thickness of 10 mm and dried with a drier for 120
It was dried at 0 ° C. for 2 hours to obtain a mica sheet A having a thickness of 0.5 mm. Table 1 shows the component analysis results of the obtained mica sheet A. Next, with respect to the obtained mica sheet A, the weight change of the mica sheet was measured using a differential thermal analyzer.
As a result, 850 ℃ or in Weight changes were not observed.
The following mechanical strength and hygroscopicity measurement tests were conducted.
The results are shown in Table 2.

Mechanical Strength Measurement Test In accordance with the method specified in JIS-Z-1702, the tensile strength of the mica sheet was measured at room temperature using an Instron type tensile tester. Mica sheets hygroscopicity test dried for 24 hours at 80% of the atmospheric humidity were measured moisture absorption.

Example 2 The synthetic fluoromica A obtained in Example 1 was washed with distilled water, 35 ml of a 15% aqueous barium chloride solution was further added, and the mixture was slowly stirred at room temperature for 3 hours using a stirrer to synthesize.
Fluorine mica B was obtained. This synthetic fluoromica B contains most of the intercalation Na ⁺ contained in the swelling fluoromica.
Was replaced by K ⁺ and Ba ²⁺ . This synthetic fluoromica
The B, and in the same manner as in Example 1, filtered, and leveling and drying,
Mica sheet B was obtained. Table 1 shows the component analysis results of the obtained mica sheet B. The heat resistance of the obtained mica sheet B was evaluated in the same manner as in Example 1. As a result, 850 ℃ or in Weight changes were not observed. Further, in the same manner as in Example 1, mechanical strength and hygroscopicity measurement tests were conducted. The results are shown in Table 2.

[0024] After washing the synthesized fluorinated mica A obtained in Example 3 Example 1 in distilled water, further 15% of lead chloride solution 45ml was added, using a stirrer, and stirred gently at room temperature for 3 hours, the synthetic Fluorine mica
I got C. In this synthetic fluoromica C , most of the interlayer ions Na ⁺ contained in the swelling ^fluoromica were replaced with K ⁺ and Pb ²⁺ . This synthetic fluoromica C was filtered, spread and dried in the same manner as in Example 1 to obtain a mica sheet C. Table 1 shows the results of component analysis of the obtained mica sheet C. The heat resistance of the obtained mica sheet C was evaluated in the same manner as in Example 1. As a result, 850
℃ or in Weight changes were not observed. Further, in the same manner as in Example 1, mechanical strength and hygroscopicity measurement tests were conducted. The results are shown in Table 2.

Comparative Example 35 parts by weight of silicic acid anhydride, 30 parts by weight of magnesium oxide,
10 parts by weight of aluminum oxide and sodium fluorosilicate
After mixing 20 parts by weight and melting at about 1500 ° C., 130
It crushed those crystallized at 0 ° C., to obtain a swellable fluorine mica (hereinafter referred to as soluble fusion formed mica) by the melting method. This melting
20.0 g of synthetic mica was treated in the same manner as in Example 1 with interlayer
A comparative synthetic fluoromica was obtained in which some of the on Na ⁺ was replaced with K ⁺ . Further, in the same manner as in Example 1 , filtration, spreading and drying were performed to obtain a comparative mica sheet having a thickness of 0.5 mm. The obtained compared mica sheet, the heat resistance was evaluated in the same manner as in Example 1. As a result, weight change up to 8 50 ° C. was observed. Also, in the same manner as in Example 1, mechanical
Strong degree and was hygroscopic measurement test. The results are shown in Table 2.

[0026]

[Table 1]

[0027]

[Table 2]

(Evaluation) As is clear from Table 2, the tensile strength is 5 kg / mm ² or more for the mica sheet A and 6 kg / mm ² or more for the mica sheets B and C, and the moisture absorption is 1%.
In the heat resistance evaluation, no weight change was observed up to 850 ° C., and all mica sheets showed excellent results. In contrast, manufactured from fused synthetic mica
The tensile strength of the comparative mica sheet was 1.5 kg / mm ² , which was lower than that of the product of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inoue Tsunematsu Kinue 807 Nonoshita, Yadomachi, Tosu City, Saga Prefecture 1 Kuju Industrial Research Institute (72) Satoshi Nishimura 807, Nozoshi, Nojushicho, Tosu City, Saga Prefecture In the State Industrial Technology Laboratory (72) Naoichi Hara, No. 807, Nonoshita, Yado-machi, Tosu City, Saga Prefecture 1 In the Industrial Technology Laboratory, Kyushu (72) Yutaro Ishida, 23, Ichibancho, Chiyoda-ku, Tokyo 3 Corppe Chemical Stock In-house (72) Inventor Takashi Furusawa, 3 Enokicho, Niigata City, Niigata Prefecture, Corp. Niigata Laboratory (72) Inventor, Seinosuke Ando, 23, Ichibancho, Chiyoda-ku, Tokyo Within Corp Corp. (72) Inventor Mitsuru Kimura 23, Ichibancho, Chiyoda-ku, Tokyo 3 Co-op Chemical Co., Ltd.

Claims (4)

[Claims] 1. The following formula (I): αMF · βLF · γ (aMgF ₂ · bMgO) · δSiO ₂ (I) (wherein M is an interlayer ion, K ⁺ or K ⁺ and Ba ²⁺ and / Or Pb ²⁺ , L is an interlayer ion and represents Na ⁺ or Li ⁺ , α and β represent 0 to 2 and α + β is 0.1 to 2, and γ is 2 To 3.5, δ represents 3 to 4, and a and b represent 0 to 1 respectively.
And a + b = 1), which is composed of an ion-exchanged synthetic swellable fluoromica complex. 2. A mixture obtained by heat-treating a mixture of sodium silicofluoride or lithium silicofluoride and talc, or a mixture of sodium silicofluoride or lithium silicofluoride and sodium fluoride or lithium fluoride and talc by an intercalation method. And the following formula (II): (α + β) LF · γ (aMgF ₂ · bMgO) · δSiO ₂ (II) (wherein L is an interlayer ion and represents Na ⁺ or Li ⁺ , and (α + β) is 0. . 1-2, and γ is 2-3.
5, δ represents 3 to 4, a and b each represent 0 to 1 and a + b = 1), and the synthetic swelling fluoromica and the potassium salt aqueous solution are mixed and stirred to form an interlayer. A method for producing a mica sheet, characterized in that a synthetic swellable fluoromica composite having a composition according to claim 1 in which ions are ion-exchanged with K ⁺ is obtained, and this is dried into a sheet. 3. A synthetic swellable fluoromica complex represented by the formula (II) according to claim 2 is mixed with an aqueous potassium salt solution and stirred to form a synthetic swellable fluoromica complex in which interlayer ions are ion-exchanged with K ^+. 2. The synthetic swelling fluoromica composite and the barium salt and / or lead salt aqueous solution are then mixed and stirred to obtain interlayer ions exchanged with K ⁺ and Ba ²⁺ and / or Pb ^2+. A method for producing a mica sheet, which comprises obtaining a synthetic swellable fluoromica composite having the composition described and drying the composite into a sheet. 4. The synthetic swelling fluoromica represented by the formula (II) according to claim 2 and a barium salt and / or lead salt aqueous solution are mixed and stirred to form interlayer ions into Ba ²⁺ and / or Pb ²⁺ . An ion-exchanged synthetic swellable fluoromica composite is obtained, and then the synthetic swellable fluoromica composite is mixed with an aqueous potassium salt solution and stirred to form K ⁺ and Ba ²⁺ and / or Pb ²⁺ as interlayer ions. A method for producing a mica sheet, which comprises ion-exchanged to obtain a synthetic swellable fluoromica composite having a composition according to claim 1, and drying the composite into a sheet.