JPH05306115A - Production of mica particles - Google Patents

Abstract

PURPOSE:To provide a production method of mica particles which enable to perform an isomorphous substitution and incorporates a flat hexagonal plate form or a nearly hexagonal plate form particle in the mica surface. CONSTITUTION:A clay mineral, a compound of a transition metal and a fluoride are mixed so as to become a compound composition of an aimed mica and the mixture is heated at a high temp. lower than the m.p. When the obtained mica particles are mixed in a cosmetics, they impart smoothness to the skin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing mica particles containing hexagonal plate-like particles having a smooth mica surface and capable of performing isomorphic substitution (composition conversion) over a wide range, or particles having a shape close to hexagonal plate-like. Is.

[0002]

2. Description of the Related Art Synthetic mica is used for heat insulating materials, paints, resin fillers,
It is used in various applications such as welding rods, lubricants and cosmetics. Conventionally, such synthetic mica is mainly composed of a hydrothermal synthesis method of synthesizing in a pressure vessel at high temperature and high pressure, a melt synthesis method of synthesizing in a heat-resistant vessel at high temperature, and a solid-state reaction in which a fine powder raw material is compressed and heated for a long time. Is synthesized by the method.

However, since the hydrothermal synthesis method requires high temperature and high pressure, there is a problem of poor productivity, and the melt synthesis method needs to be pulverized because it is obtained in the form of an ore ingot. It is difficult to smooth the particle surface,
Since the particle size distribution after crushing is wide, it has to be classified, which increases the number of working steps and reduces the product yield.In addition, the composition range of mica that can be synthesized is narrow and high temperature is required, resulting in high cost. However, the reaction method between solids has a problem that the surface of the mica particles is difficult to be smooth. As described above, the conventional method for producing mica is not yet industrially sufficiently satisfactory.

On the other hand, as an additive for cosmetics and the like, mica that is slippery on the skin is required, and as an additive for plastics and paints, a mica having a transparent feeling is required. The mica used for the above purpose is preferably a hexagonal plate-shaped crystal in order to improve the slip, the surface of the mica is smooth, and to avoid the diffused reflection to provide a transparent feeling. Mica is not currently marketed because its industrial production is unknown. In addition, synthetic mica imparts functions such as ultraviolet absorption ability by isomorphic substitution with various types and amounts of ions, but with conventional methods, the types and amounts of ions that can be isomorphically substituted are limited. Therefore, there was a limit to functionalization.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and industrially provides a hexagonal plate-shaped synthetic mica in which the ion species and the amount of isomorphous substitution can be controlled and the particle surface is smooth. An object is to provide a method of easily manufacturing.

[0006]

In order to achieve the above object, the inventors of the present invention have, as a result of diligent studies, pulverized a mica raw material, and heated the above at a high temperature below the melting point of mica to achieve the above object. The inventors have found what has been achieved and have reached the present invention. That is, the present invention is characterized in that the viscous mineral, the compound of the transition metal and the fluoride which are mixed so as to have the intended composition of mica are heated at a high temperature below the melting point of mica.

The synthetic mica produced according to the present invention has the following formula
It can be represented by the general formula (1). X_{1/3 ~ 1}Y_2-3 Z_Four O_Ten F₂ (I) Each of the above X, Y, and Z positions has one of the following ions
Has more than one kind of coordination. X: K⁺, Na⁺, Li⁺, Ca²⁺, Ba²⁺, Sr²⁺, Rb²⁺  Y: Mg²⁺, Fe²⁺, Ni²⁺, Ti²⁺, Zn²⁺, Cu²⁺, Mn²⁺, Al³⁺, Fe³⁺, Co³⁺ Z: Al³⁺, Fe³⁺, B³⁺, Si⁴⁺, Ge⁴⁺ The mica raw material used in the present invention is a combination of raw materials used.
Therefore, the above-mentioned chemical composition is used or raw materials are used in the manufacturing process.
Part of the composition of Eq.
It is what you make. Such things include clay ore
Of fine powders, mixtures of transition metals and fluorides
You can use it. The degree of pulverization depends on the average particle size 0.1 to
100 μm, preferably 0.5 to 10 μm.

Further, in order to obtain a synthetic mica having a narrow particle size distribution width, it is advisable that a suspension obtained by suspending the above-mentioned finely divided raw material in water is made into a mist and spray-dried for secondary aggregation. Spray drying may be performed at 100 ° C or higher, preferably around 200 ° C. In this step, the fine powder raw material having an average particle size of 1 μm has an average particle size of about 2 to 50 μm. By such secondary aggregation, the mica raw material is granulated into a uniform particle size. Then
Fine powder of mica raw material is used at a high temperature below the melting point of mica, preferably 8
Heat treatment is performed at 00 ° C to 1400 ° C to synthesize mica. The heat treatment time depends on the heat treatment temperature and the raw materials used,
Generally, about 3 to 5 hours is sufficient.

Conventionally, for example, by the melt synthesis method which is mainly carried out industrially, the ion species and the amount of ions for isomorphous substitution are limited. On the other hand, according to the method of the present invention, it is easy to mix the clay mineral, the compound containing the transition metal ion to be isomorphically substituted, and the fluoride so that the composition of the target mica is adjusted. The isomorphous substitution can be performed and the ion amount of the isomorphous substitution can be controlled. Examples of raw clay minerals used in the present invention include talc and kaolin. Examples of the compound containing an ion to be isomorphically substituted include oxides and carbonates of ions to be isomorphically substituted, such as manganese carbonate, zinc carbonate, cobalt carbonate, nickel carbonate, iron oxide and titanium oxide. .. Examples of the fluoride include alkali fluorides such as potassium fluoride, potassium silicofluoride, sodium fluoride and sodium silicofluoride.

[0010]

EXAMPLES Next, the present invention will be further described with reference to examples, but the present invention is not limited to these examples. Example 1 Kaolin represented by the composition Al ₂ Si ₂ O ₅ (OH) ₄ 1/2 mol, potassium silicofluoride 1/3 mol, potassium carbonate 1/6 mol, magnesium oxide 5/2 mol, silicon oxide 5 / 3 mol and manganese carbonate 1/2
The molar formulation was pulverized and mixed to have an average particle size of 3 μm, and the pulverized mixture was heat treated in an alumina crucible at 1000 ° C. for 5 hours,
Composition in which part of the octahedron is replaced with zinc KMg _2.5 Zn _0.5 (AlSi ₃ O
A mica crystal represented by ₁₀ ) F ₂ was obtained. Example 2 1/3 mol of talc represented by the composition Mg ₃ Si ₄ O ₁₀ (OH) ₂ , 1/3 mol of potassium silicofluoride, 1/6 mol of potassium carbonate, 3/2 of iron oxide.
Mol and 4/3 mol of silicon oxide were pulverized and mixed to have an average particle size of 1 μm or less, and an aqueous suspension of the pulverized mixture was heated to 200 ° C.
Was spray-dried and collected in the state of secondary aggregation having an average particle size of 3 μm.
This was heat-treated in an alumina crucible at 1000 ° C. for 5 hours, and a composition in which part of the tetrahedron was replaced with trivalent iron and part of the octahedron was replaced with divalent iron KMgFe ₂ (FeSi ₃ O ₁₀ ). A mica crystal represented by F ₂ was obtained.

Example 3 1/3 mol of talc represented by the composition Mg ₃ Si ₄ O ₁₀ (OH) ₂ , 1/3 mol of potassium silicofluoride, 1/6 mol of potassium carbonate, 1 mol of magnesium oxide, 1 manganese carbonate. Moles, 1/2 moles of boron oxide and 4/3 moles of silicon oxide were finely mixed to an average particle size of 1 μm or less, and an aqueous suspension of this fine powder mixture was spray-dried at 200 ° C. to give an average particle size of It was recovered in a secondary aggregation state of 3 μm. This was heat-treated in an alumina crucible at 1000 ° C. for 5 hours, and part of the tetrahedron was replaced with boron, and part of the octahedron was replaced with manganese. The composition is represented by KMg ₂ Mn (BSi ₃ O ₁₀ ) F _2. A mica crystal was obtained. Example 4 Kaolin represented by the composition Al ₂ Si ₂ O ₅ (OH) ₄ 1/2 mol, potassium silicofluoride 1/3 mol, potassium carbonate 1/6 mol, cobalt carbonate 3 mol and silicon oxide 5/3 mol. Formulated with an average particle size of 3 μm
Pulverize and mix, and mix this fine powder mixture in an alumina crucible with 1
After heat treatment at 000 ° C. for 5 hours, a mica crystal represented by the composition KCo ₃ (AlSi ₃ O ₁₀ ) F _{2 in} which cobalt was coordinated to an octahedron was obtained.

Example 5 Kaolin represented by the composition Al ₂ Si ₂ O ₅ (OH) ₄ 1/2 mol, potassium silicofluoride 1/3 mol, potassium carbonate 1/6 mol, nickel carbonate 3 mol and silicon oxide 5 Average particle size of 1 μm
Finely mix the following, and add an aqueous suspension of this fine powder mixture to 200
It was spray-dried at ℃ and collected in the state of secondary aggregation having an average particle size of 3 μm. This was heat-treated in an alumina crucible at 1000 ° C. for 5 hours to give a composition of octahedrally coordinated nickel KNi ₃ (AlSi ₃ O ₁₀ ) F ₂
A mica crystal represented by Example 6 Kaolin represented by the composition Al ₂ Si ₂ O ₅ (OH) ₄ 1/2 mol, potassium silicofluoride 1/3 mol, potassium carbonate 1/6 mol, titanium oxide
Formulation of 1/2 mol and 5/3 mol of silicon oxide with an average particle size of 3 μm
Finely mix the following, put this fine powder mixture in an alumina crucible, and heat-treat at 1000 ° C for 5 hours in a reducing atmosphere to prepare a composition KM
g _2.5 Ti ²⁺ _0.5 (AlSi ₃ O ₁₀ ) F ₂
^{A 2+} substituted mica crystal was obtained.

[0013]

According to the present invention, clay minerals, transition metal compounds and fluorides are pulverized and heated at a high temperature below the melting point of mica. Obtained as a mica. At present, a special pulverization method is used to impart smoothness to the mica particles, but it is extremely difficult to obtain the smoothness obtained by the present invention. Further, during the heat treatment, by mixing a compound containing a transition metal ion to be isomorphically substituted with the clay mineral and a fine powder of fluoride, the kind and amount of the ions in the obtained synthetic mica can be selected from a wide range. You can choose. That is, by replacing the mica with the same shape, it imparts functions such as ultraviolet absorption ability, but in the conventional method,
Since the type and amount of ions that can be isomorphically substituted were limited,
There was also a limit to functionalization. According to the method of the present invention, the isomorphic substitution can be carried out in a wide range, so that it becomes possible to give the obtained synthetic mica a lot of functions which have never been obtained.

[0014]

[Effect] As described above, according to the present invention, by finely pulverizing a clay mineral, a compound of a transition metal and a fluoride, and heating and recrystallizing the mixture at a temperature below the melting point of mica,
The surface of the mica, which has not been conventionally industrially produced, is extremely smooth and can be easily obtained as a highly functional hexagonal plate-shaped mica containing a desired amount of a desired transition metal ion. Mica having such properties imparts smoothness to the skin when mixed in cosmetics, and imparts transparency when used as an additive such as plastic, which is extremely useful in industry. It is a thing.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masato Kuratani, 5th, 4th-cho, Chiyoda-ku, Tokyo 9 Topy Industries Co., Ltd.

Claims (1)

[Claims] 1. A method for producing mica particles, which comprises mixing a clay mineral, a compound of a transition metal, and a fluoride so as to have a composition of a target mica, and heating the mixture at a high temperature below the melting point. Method.