JPS591215B2 - Fluorine mica and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel fluorinated mica useful as various electrical insulating materials, heat-resistant fillers, heat-resistant paints, mold release agents, and sliding materials, and a method for producing the same.

Conventionally, fluorine mica has been produced using silica, magnesia, alumina, and fluoride as raw materials (at high temperatures of 1300°C or higher).
A method in which fluorine mica is mixed with feldspar, olivine, quartz, fluoride, etc. by the so-called melting method, and the mixture is gradually heated and reacted at 1000°C or higher for 2 to 24 hours. Fluorine mica produced by a solid-state reaction method is known.

However, the fluorine mica obtained in this way is phlogopite (
KMg3Si3AlO1oF2)
KMg2.5Si40, which contains l2O3 or does not contain Al2O3.

F2 or KMg2.75 (s i3.75 Mg,), 2
5) It has the chemical structural formula 010F2.

However, with these methods for producing fluorine mica, for example, in the case of the melting method, the temperature is too high, and in the solid-state reaction method, the sample must be sufficiently mixed in order to react uniformly, and the reaction time is too high. It has drawbacks such as being too long.

The present invention provides talc powder with 15 to 2 parts per weight.
Fluorine mica can be obtained by adding alkali metal fluorine compound powder of Section 5 and heat-treating the mixture at 800 to 1200°C. In this way, fluorine mica can be produced in an extremely short time compared to conventional methods. According to the present invention, it is possible to produce fluorinated mica in large quantities continuously at an extremely low cost. can.

Furthermore, the fluorine mica of the present invention differs from conventional ones in that Al2
Compositional formula MF that does not contain O3, 3Mg0゜4Si02 (M
It is a new substance represented by Na, Na or Ni).

In the method of the present invention, fluorinated mica can be produced even if the talc used as a raw material is not a particularly pure raw material.

This is caused by other impurity elements, such as Al2O3 and Fe2O3.
This is because even if such elements are present, these elements work to eliminate the charge imbalance of the fluorine mica structure.

In this case, although Al2O3 is partially dissolved in the structure, it does not affect the basic structure of the mica.

A commercially available industrial reagent was used as the fluoride.

The mixing ratio of talc and fluoride is 15% and 17%, respectively.

20 parts, 25 o; b were added.

In the present invention, alkali ions are introduced into the interlayers of talc by rapidly heating the mixture of the above-mentioned raw materials to 800°C to 1200°C using an electric furnace, rotary kiln, etc. and holding it for 0 seconds to 24 hours. At the same time, fluorine mica was obtained by partially replacing OH ions, which are the structural water of talc, with fluorine ions.

However, the heat treatment held for 0 seconds is defined as follows.

When a mixture with talc is maintained at a predetermined temperature and inserted into an electric furnace, the temperature inside the furnace drops several tens of degrees, and it takes several tens of seconds to return to the predetermined temperature again.

In other words, holding for 0 seconds means that as soon as the temperature reaches the specified temperature again,
This refers to the heat treatment performed when a sample is removed from the furnace.

The influence of heating temperature and heating time on the yield of fluorine mica is as shown in FIG.

As can be seen from Figure 1, if the temperature is 1000℃ or higher, even if the heat treatment time is 0 seconds, the fluorine mica is sufficiently converted.
Force heating at 1000°C or higher is preferred.

Even at 800°C and 2900°C, if the heat treatment time is increased,
Completely converts into fluorinated mica.

Although it is possible to produce fluorine mica by heating at 1200°C or higher, the powder is sintered, so it is necessary to pulverize the production material.

Furthermore, those heat-treated at 1000° C. are obtained in powder form, and since only fluorine mica is obtained, there is no need for separation or pulverization, and the product can be used as is.

The fluorinated mica of the present invention is produced by heating talc to 850°C to 1200°C using an electric furnace or rotary kiln and holding it for a while, so that alkali ions penetrate into the interlayers of talc and form the same shape as the talc. Fluorine mica is obtained by simultaneous ion substitution of structural water with fluorine ions.

It is clear from the one-dimensional electron distribution density diagram shown in FIG. 2 that ions have penetrated into the interlayer region.

This is because, in talc, there are no ions at the position of potassium in Figure 2, that is, in the interlayer region.

In other words, the presence of an ion peak in the interlayer region indicates that talc has changed to fluorinated mica, and similar to the results of qualitative X-ray diffraction analysis, it can be confirmed that fluorinated mica has been produced. .

Judging from the above experimental results, the chemical structural formula of the fluorinated mica according to the present invention is not produced under very stable conditions as in the conventional method, and therefore K ions penetrate into the interlayers of talc at the same time. , two of the four OH ions in the unit cell of talc are replaced by F ions, and the others remain as 0 ions, KMg3Si40.1F, NaMg5Si4011F
.

It has an anion structure like LiMg5Si401,F.

Since this 011F anion structure is generally typical of crystals having a double-chain structure, it can be seen that the fluorinated mica according to the present invention is quite unique.

Fluorine mica (KMg3 S t 40 t t
Figure 3 shows the change in electrical conductivity during the heating process of F).

Fluorine mica has a quite unique composition, but about 500
Celsius, the electrical conductivity is 1011, which is a much smaller value than mica ceramic, making it a good electrical insulating material.

For example, it is suitable as a high-resistance material for precision analysis devices and control devices used at high temperatures, as a filler for heat-resistant and insulating materials, or as a heat-resistant paint.

Example 1 After pulverizing talcum, it was sieved to use the talc with a diameter of 74 μm or less as a raw material.

First, raw materials and fluoride were mixed at predetermined ratios (25%).

This mixture was placed in a platinum crucible, rapidly heated, and held for a predetermined time to obtain fluorine mica.

The production rate of fluorine mica was measured by the X-ray powder method.

That is, the area of the diffraction peak of fluorinated mica was divided by the sum of the area of the diffraction peak of fluorinated mica, the area of the diffraction peak of talc, and the area of the diffraction peak of talc, and the value was taken as the production rate of fluorinated mica.

The results are shown in Figure 1, and the production rate was 100% by heating at 1,000°C or higher and in a very short heat treatment time of 0 seconds.
We were able to produce fluorine mica.

Example 2 When the mixing ratio of talc and fluoride was 20%, pyroxene was obtained at the same time as fluorine mica.

When the mixing ratio was 20%, 17%, and 15%, substances other than fluorine mica were obtained at about 10'%, 20%, and 30%, respectively.

The minerals were determined by the X-ray powder method.

Example 3 When the mixing ratio of talc and fluoride (in this case, only KF) is 25%, 20 parts, 17 parts, and 15 parts, the mixture is placed in a platinum crucible and gradually heated to a treatment temperature. By varying the holding time within the range of 800° C. to 1200° C., results similar to those shown in FIG. 1 were obtained.

However, in this case, compared to Examples 1 and 2, slightly more substances other than the target mineral were obtained. By reheating the heat-treated fluorinated mica, substances other than the target mineral disappeared, and only pure fluorinated mica could be obtained.

The results are shown in FIG. If you reheat it two or more times,
Pure fluorinated mica was obtained.

[Brief explanation of the drawing]

Figure 1 shows that when the mixing ratio of talc and fluoride is 25%,
Figure 2 is a diagram showing the relationship between the heat treatment temperature and the production rate of fluorine mica, and is a one-dimensional mica distribution density diagram of fluorine mica obtained when the holding time was 0 seconds in Example 1. It is clear that it has penetrated into the body. Figure 3 shows the change in electrical conductivity of fluorine mica during the temperature rising process (fluorine mica produced with a holding time of 0 seconds in Example 1), and Figure 4 shows the production rate of fluorine mica due to reheating. FIG.

Claims (1)

[Claims] 1. Fluorine mica represented by the compositional formula MP.3Mg0.4S102 (where M is 2, Na, or Li). 2 For talcum powder, 15 to 25 per weight
A composition formula characterized by adding the related alkali metal fluorine compound powder and heat-treating the mixture at 800 to 1200°C.
2, Na, or Li).