JPS5839566B2 - Alkali Kinzoku Bun Santa Ino Seizou Hohou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improved method of making an alkali metal dispersion.

The alkali metal dispersion is used, for example, in (1) to remove from the system, in addition to the crude diolefin monomer, active hydrogen compounds that react with the alkali metal during the purification of the diolefin monomer (2). It is used as one of the main raw materials in the production of alphine catalysts, (3) as a polymerization catalyst for diolefin or monoolefin monomers, and (4) for carrying out reduction and other chemical reactions.

Manufacturing methods include high-speed stirring method, colloid mill method,
Jet method, ultrasonic method, etc. are known.

In both of these methods, an alkali metal is placed in a dispersion medium.
While heating above the melting point of the alkali metal, use physical means to disperse the alkali metal into fine particles to form an emulsion, and after sonication, cool to below the melting point of the alkali metal while maintaining the dispersed state to obtain an alkali metal dispersion. It is something.

The more uniform and smaller the particle size of the alkali metal dispersion, the larger the surface area of the alkali metal and the higher the reactivity of the alkali metal.

The particle diameter of the alkali metal dispersion is usually 1 to 100 microns, preferably 20 microns or less, and ideally has good dispersion stability.

When producing an alkali metal dispersion, three methods can be adopted: a batch method and a continuous method, but the latter method is more desirable in industrial production.

That is, the batch method requires a larger dispersion device and cooling device than the continuous method, and the quality of the dispersion differs from batch to batch, which has the disadvantage that the quality is not constant.

A method for continuously producing an alkali metal emulsion (emulsion at a temperature above the melting point) is, for example, an Al
kali Metal Dispersions 51
Pages ~ 55 (I, KATT, M, TASHI
Written by M.A.

VAN N08TRAND CO1 (published in 1961) and Special Publication No. 16923 (1977).

The former shows a typical method for continuously producing an alkali metal emulsion (emulsion at a temperature above the melting point).

This method is used to reduce the emulsion particle size.
Since it is necessary to have an average residence time of at least about 30 minutes in the emulsifying device, there is a disadvantage that the dispersing device becomes large despite the small production amount per unit time.

In addition, this method has the disadvantage that the emulsion that is discharged as a short-circuit flow is mixed in before the dispersion is sufficiently finely dispersed, resulting in an alkali metal dispersion containing particles with large particle diameters.

The latter Japanese Patent Publication No. 41-16923 has been proposed as a method for overcoming the drawback of the incorporation of dispersions with large particle diameters.

This method uses an apparatus equipped with an emulsifying machine connected by a circulating line in addition to the main body of the dispersion apparatus, and is intended to obtain an alkali metal dispersion with a narrow particle size distribution.

However, this method has the disadvantage that the apparatus is larger and more complicated than the former method compared to the production volume.

As a result of various studies on dispersion and emulsification equipment suitable for obtaining alkali metal dispersions, the present inventors found that using a multi-pass emulsifier, the structure of which is shown in Fig. 1, allows alkali metals with a narrow particle size distribution to be It has been discovered that emulsions can be obtained satisfactorily.

According to this knowledge, the multi-pass emulsifier is smaller than any conventionally known alkali metal emulsion manufacturing equipment in terms of production capacity, and it is also possible to reduce the long residence time required by conventional emulsifiers. Uniform emulsions can be produced without the need to repeatedly run the raw material through an emulsifier.

The multi-pass emulsifier used in the present invention has a structure as shown in FIG.

In the figure, reference numeral 1 denotes a main cylinder having a lid 2 at the top, and a stator 3 having vertical openings is provided at the lower center of the main cylinder, and the stator is attached to the lid 2 by a rod 4.

A turbine 5 is disposed within the stator 3 and is supported by a shaft 7 connected to a motor 6 for producing an upwardly directed axial flow.

Reference numeral 8 denotes an injection port provided at the lower part of the main cylinder 1, and is formed facing the opening of the stator=3.

Reference numeral 9 denotes a discharge groove provided so as to surround the upper part of the main cylinder 1, and the upper part of the groove drains the main cylinder 1 through an overflow gap 10 formed between the upper edge of the main cylinder 1 and the lid 2. It communicates with the inside,
A discharge port 11 is provided at the bottom thereof.

12 is a bearing case, and 13 is a motor mounting base.

According to this emulsifier, the fluid flows from the inlet 8 to the stator 3.
The turbine 5 causes the flow to flow upward in the axial direction, reverse as shown by the arrow, descend along the inner wall of the main cylinder 1, and stay again! 51-3 to form a circulating flow.

A part of the circulating flow passes through the overflow gap 10, enters the discharge groove 9, and is discharged from the discharge port 11.

The manufacturing process for alkali metal dispersions consists of the first half of the process of creating an emulsion at a temperature above the melting point, and the second half of the process of cooling this high-temperature emulsion below the melting point to make a stable dispersion. Separated.

Obtaining an alkali metal emulsion at a temperature above the melting point of the alkali metal and then cooling it below the melting point is a simple process, but one that is prone to failure.

In other words, when an alkali metal that is stably finely dispersed in a molten state is cooled and changed into a finely dispersed solid state below the melting point, that is, it is cooled from a temperature slightly higher than the melting point to a temperature several tens of degrees lower than the melting point. During this period, the alkali metal dispersion is very unstable, and even a slight shock destroys the dispersion state and causes aggregation of the alkali metal dispersion.

Therefore, during cooling, rapid cooling, stirring, and movement are strictly prohibited, and the commonly used method is to store it in batches in a tank and then slowly cool it from the melting point to several tens of degrees Celsius below the melting point without stirring or moving. There is.

For this reason, it is not possible to take the raw material into or out of the cooling tank during cooling, so two or more cooling tanks are required, and there is a serious drawback that the reproducibility of the production of the alkali metal dispersion is poor.

As a result of various studies on cooling methods for alkali metal emulsions, the present inventors found that
When an alkali metal emulsion at a temperature above the melting point is continuously injected into a dispersion medium that is cooled to a temperature lower than 0°C and stirred and rapidly cooled, a stable alkali metal dispersion at a temperature below the melting point is continuously produced. They discovered that the present invention can be obtained, and in combination with the alkali metal emulsification method described above, completed the method for producing an alkali metal dispersion of the present invention.

This cooling method may be a conventional method, such as Encyclopedia of Polymer 5.
science and technology vol.
, 12 615 pages, starting from line 11 from the bottom (1970
This is an amazing method that completely contradicts the technical philosophy of ``Do not stir during cooling'' as stated in the 2011 publication.

Alkali metals used in the method of the invention include sodium, lithium and potassium.

The dispersion medium used in the method of the present invention is not particularly limited as long as it is inert to alkali metals and is liquid under the conditions for producing the dispersion.

For example, aliphatic hydrocarbons such as n-octane, n-nonane, n-decane, trimethylpentane, cyclohexane,
Aliphatic hydrocarbons such as cycloheptane and dimethylcyclohexane, aromatic hydrocarbons such as benzene, toluene, and xylene, and high-boiling hydrocarbon mixtures with a boiling point of 100°C or higher distilled from petroleum, such as kerosene and liquid paraffin. used.

In the production of alkali metal dispersions, in order to facilitate emulsification and dispersion and increase the stability of emulsions and dispersions,
It is common practice to add a dispersant to a dispersion medium.

The method of the invention also requires the use of a dispersant.

Examples of dispersants include higher fatty acids such as stearic acid and oleic acid, alkylarylsulfonic acids, alkylsulfonic acids, higher alcohol sulfates, and salts thereof.

These dispersants are generally used in an amount of about 5% by weight or less, preferably 0.3 to 3% by weight, based on the alkali metal.

In addition, the concentration of alkali metal in the alkali metal dispersion is 60
It is adjusted to be less than 5% by weight, preferably 5 to 40% by weight.

The temperature during production of the alkali metal emulsion is higher than the melting point of the alkali metal around the multi-pass emulsifier, 181-220°C for lithium, 98-1°C for sodium.
40°C, and 63 to 90°C for potassium, while the temperature to be cooled is preferably at least 10°C lower than the respective melting points.

Containers for cooling alkali metal emulsions include:
A sufficient amount of a cooled dispersion medium or a dispersion medium containing an alkali metal dispersion is provided to receive the hot emulsion above the melting point and instantly reduce the temperature to 10°C or more, preferably 20°C or more below the melting point. It must be present at all times, and this cold dispersion medium must be agitated so that the hot dispersion is instantaneously dispersed and cooled.

The cooled dispersion is extracted continuously or batchwise for use.

As a method for cooling an alkali metal emulsion, it is desirable to provide a jacket or coil in a container that receives the emulsion, and to flow a refrigerant through the jacket or coil.

However, the solution can also be cooled by circulating it in a cooler provided separately from the container.

Furthermore, when there is no problem even if the concentration of the dispersion solution decreases, the purpose can also be achieved by continuously injecting a pre-cooled solvent into the receiving container of the alkali metal emulsion.

The particle size of the dispersion obtained by the method of this invention is 100 microns or less, usually 1 to 15 microns.

Because alkali metal emulsions or dispersions are highly reactive with air, water, etc., the alkali metals are handled under inert gas throughout the dispersion manufacturing process.

An example of the method for producing an alkali metal dispersion according to the present invention will be described in detail with reference to FIGS. 1 and 2 as follows.

As shown in FIG. 2, the alkali metal is sent from a molten alkali metal container 21 to a multi-pass emulsifier 25 by a pump 23.

The molten alkali metal lines and pumps are heated above their melting point.

On the other hand, the dispersion medium in which a predetermined amount of dispersant is dissolved or dispersed is sent from the container 22 to the multi-pass emulsifier 25 by the pump 24.

This dispersion medium is also heated above the melting point of the alkali metal.

As shown in FIG. 1, the processing liquid entering the multi-pass emulsifying machine through the inlet 8 is directly connected to the motor 6 and rotated by the turbine 5.
It is emulsified, pushed up, and stirred in the tank at a discharge rate several tens to hundreds of times the size of the tank.

In other words, with this stirring, the processing liquid is mixed with the coupin 5 and the stator 3.
While passing through the gap between 0.3 and 1.0 mm several tens to hundreds of times on average, the emulsion is finely dispersed and becomes an emulsion.

And the part 10 of the upper circumference of the calibration that is least affected by stirring.
It is continuously extruded from the outlet 11 and guided to the cooling tank 26.

The cooling tank 26 is preferably cooled by a jacket 28 containing a refrigerant.

A dispersion medium or an alkali metal dispersion is contained in the interior up to about 80% by volume, and is stirred by a stirrer 2T.

A high temperature emulsion is continuously injected here.

The emulsion is instantly cooled to below the melting point of the alkali metal and becomes a uniform alkali metal dispersion.

The alkali metal dispersion thus produced is continuously or batchwise extracted from the outlet 29 and used for various purposes.

The present invention will be explained below by giving examples.

Example 1 Molten sodium at a temperature of 130°C was pumped at a flow rate of 3 using an electromagnetic pump.
Continuously feed to a multi-pass emulsifier at 0 t/hour.

On the other hand, the dispersion medium kerosene containing 0.25% by weight of the dispersant aluminum distearate was pumped at a flow rate of 160 t/w.
The mixture is heated to 130°C and continuously fed to a multi-pass emulsifier.

At this time, the dispersant aluminum distearate was 1.1% by weight based on sodium, and the sodium concentration was approximately 1% by weight in the system.
It is 8% by weight.

The multi-pass emulsifying machine has a tank size of 2 (1, turbine rotation speed of 3800 r, pom, , turbine discharge rate of 400
, g/min.

The average retention time in the multi-pass emulsifier is approximately 6 to 7 minutes.
The average number of passes is 120-140.

The metal sodium dispersion continuously discharged from the multi-pass emulsifier is poured into the cooling tank of 5007 in a heated state.

The cooling tank is filled with 80% kerosene at the start of operation, and the upper space is sealed with nitrogen gas.

There is a 1.30 r, p5m stirrer in the center of the tank, and it can be considered a complete mixing tank.

Kerosene at 0 to 10°C is passed as a refrigerant through the jacket outside the tank, and the internal solution is constantly maintained at 30 to 35°C.

A continuously heated IJium dispersion is dropped into this from the top and rapidly cooled, and the molten sodium is instantly solidified to form a sodium dispersion at 30 to 35°C.

The amount of extraction is adjusted so that the inside of the cooling tank is filled to about 80%.

A sodium dispersion was produced continuously for 10 days by this method, and no problems occurred during this period.

Thereafter, all of the dispersion in the cooling container was discharged and the inside was observed, but no sodium lumps were observed.

When the particle size distribution of the sodium dispersion thus obtained was measured using a microscope, the particle size range was 1 to 15 μm.
The average particle size was 8μ.

Comparative Example 1 About 3 tons of the sodium dispersion obtained by the method of Example 1 at about 110° C. was received in a stainless steel container with an internal volume of 5 tons sealed with nitrogen gas and cooled under the conditions shown in the table below.

After cooling to room temperature, the dispersion was discharged and the inside of the container was observed.

The results are shown in the table below. From these comparative examples, it will be understood how difficult it is to quantitatively obtain a room temperature sodium dispersion by cooling a high temperature sodium dispersion.

Example 2 Example 1 A lithium dispersion is produced using equipment 1/10th the size.

Molten lithium at a temperature of 220° C. is continuously supplied at a flow rate of 3 t/hour to a multi-pass emulsifier with a tank size of 2 t.

On the other hand, the dispersion medium liquid paraffin containing 0.25% by weight of the dispersing agent aluminum distearate was pumped at a flow rate of 16. g
/hour to 220°C and continuously fed to a multi-pass emulsifier.

The multi-pass emulsifier has a turbine rotation speed of 380 Or, p, m.
, , the turbine is operated at a discharge rate of 401/min.

At this time, the dispersant aluminum distearate is 2.2% by weight based on lithium, and the lithium concentration is about 10% by weight in the system.

The cooling tank with an internal volume of 5 (l) is filled with 80% liquid paraffin in advance, and the upper space is filled with argon gas.

Kerosene at a temperature of 10 to 30°C is passed through the jacket outside the tank as a refrigerant to maintain the internal solution at a temperature below 60 to 70°C.

Also, the internal solution is 130 r, p, m. Stir to make a complete mixing tank.

A high-temperature lithium dispersion is continuously dropped into this from the top and rapidly cooled, instantly solidifying the molten lithium.
Lithium dispersion below ~70°C.

A lithium dispersion was produced continuously for 5 hours using this method, and no problems occurred during this time.

Thereafter, all the dispersion in the cooling container was discharged and the inside was observed, but no lumps of lithium were found.

When the particle size distribution of the lithium dispersion thus obtained was measured using a microscope, the particle size range was 3 to 20 μm, and the average particle size was 12 μm.

[Brief explanation of drawings]

FIG. 1 is a sectional front view of essential parts showing an example of a multi-pass emulsifying machine used in the method of producing an alkali metal dispersion according to the present invention, and FIG. 2 is a 70-sheet diagram of the method of the present invention. 1... Main cylinder, 3... Stator, 5...
...Turbine, 6...Motor, 8...
...Inlet, 9...Drain groove, 10...
... Overflow gap, 11 ... Outlet, 21 ...
... Molten alkali metal container, 22 ... Dispersion medium container, 23.24 ... Pump, 25 ...
Multi-pass emulsifier, 26... Cooling tank, 27...
... Stirrer, 28 ... Jacket, 29 ...
····Vent.

Claims (1)

[Claims] 1. A molten alkali metal emulsion is produced by continuously feeding a molten alkali metal, a dispersant, and an inert dispersion medium into a multi-pass emulsifier, and this emulsion is transferred to a stirred, cooled inert dispersion machine. 1. A method for producing an alkali metal dispersion, which comprises continuously injecting a medium into a container and rapidly cooling it to a temperature 10° C. or more lower than the melting point of the alkali metal.