JP5248721B2 - Method and apparatus for distillation purification of high melting point organic materials - Google Patents

Description

  The present invention relates to a distillation purification method and apparatus for a high melting point organic material.

  Generally, techniques such as recrystallization, adsorption separation, distillation, and sublimation are used for purification of organic materials.

  Purification using recrystallization is a purification method that utilizes the difference in solubility depending on the temperature of the substance, but it is difficult to select the solvent that can be used, the difference in solubility due to temperature is small, even if there is a difference in solubility, the solubility itself is small. There may be a problem that a large amount of solvent is required to carry out a specified amount of purification.

On the other hand, when using adsorptive separation, it is difficult to select an adsorbent, and organic materials with a high melting point generally have low solubility in general-purpose organic solvents. A large amount is required.
Furthermore, in the purification using these solvents, it is necessary to remove the used solvent. However, depending on the material, a mixed crystal with solvent molecules may be formed, and a trace amount of residue needs to be considered. This is a problem for materials that require a high degree of purification.

In distillation purification, it is not necessary to consider the above problems as long as thermal stability can be ensured. However, in high-melting-point materials, clogging in the rectifying section for increasing the distillation accuracy and piping for guiding the purified product to the collecting section becomes a big problem, and in order to prevent this, a powerful heat insulating material or It becomes necessary to take heat insulation measures such as heating the entire pipe uniformly, which makes the enlargement of the apparatus and the maintenance of the apparatus difficult.
Molecular distillation is a technique in which the above-mentioned problems are relatively unlikely to occur, and an apparatus used in “Experimental Chemistry Course” (Maruzen) Basic Operation 1 ”has been introduced. However, if the target purified material contains impurities with near boiling points, it does not have a rectifying section for precise separation control, so it is difficult to condense and collect only the target substance. is there.
It is publicly known that sublimable materials can be purified using an apparatus similar to molecular distillation, and an improved method is disclosed in Japanese Patent Application Laid-Open No. 12-93701. There are few organic compounds in general, and the usable range is limited.

Problems to be solved by the invention

  The object of the present invention is to uniformly heat a small amount of a large amount of feedstock in a short time, and to control the heating temperature and the collection temperature with high accuracy, thereby making it difficult to purify by a general method. An object of the present invention is to provide a method and apparatus for efficiently purifying a material by distillation.

Means for solving the problem

[Means for Solving the Problems]
The distillation purification method of the present invention has an evaporation section that evaporates and evaporates the high melting point organic material and a collection section that condenses and collects the evaporated gas, and the temperature of the collection section is substantially stepped toward the downstream side or It is continuously reduced, and at least a part of the evaporating part and the collecting part are made of a material capable of electromagnetic induction heating, and the inner surface material of the device that comes into contact with the high melting point organic material is the high melting point organic substance. A horizontal distillation purification apparatus composed of a material inert to the material is used. A material selected from metals, glass, ceramics, or fluororesin is used as the material that is inert to the high melting point organic material in the molten state . It is also advantageous to provide one or more weirs in the collecting part. Further, the distillation purification method of the present invention has a heating part and a collecting part in which at least one layer is made of a metal material, and at least a part of the outer periphery thereof is provided with an induction coil for generating heat by an electromagnetic induction method. It has a high-melting-point organic substance using a horizontal distillation refining device in which the temperature gradient is provided in the collection part so that the temperature decreases substantially stepwise or continuously toward the downstream side. The electroluminescent material as material is distilled.

That is, the present invention provides the above-described distillation purification apparatus with a collection unit having a condensation zone in which a high melting point organic material is charged into an evaporation unit, heated and melted and evaporated, and the evaporated gas is maintained in a predetermined temperature range. A distillation purification method in which the purified organic material is introduced and recovered from the zone.

  The organic material to be purified by the present invention is not particularly limited, but has a high melting point that is difficult to purify by a general method, and is particularly effective for an amorphous solid material in which a crystal takes in a solvent or the like and hardly forms a single crystal, For example, it is effective for a solid material for an electronic material or an optical material in which a small amount of impurities, a difference in crystal form, or deformation often has a great influence. Examples of such a substance include an electroluminescence element material and a semiconductor element material, which are suitable for an electroluminescence element material.

  Any electromagnetic induction heating device may be used as long as it generates heat by passing a low-frequency alternating current through a coil disposed around a conductive metal material. The frequency of the current is generally 50 to 500 Hz, and may be a commercial frequency.

  In the purification apparatus used in the present invention, the heating unit and the collection unit may be continuous or connected in the middle. However, in order to effectively perform induction heating, the heating part and the collection part are preferably cylindrical, but the diameter and the cross-sectional shape may be different on the way. According to the direction of the flow of the organic material to be purified, it has a heating part on the upstream side and a collecting part on the downstream side. And the part is comprised from the electroconductive metal material so that at least one part of a heating part and a collection part can carry out electromagnetic induction heating, and the coil is arrange | positioned in the circumference | surroundings.

  FIG. 1 is a cross-sectional view showing an example of an apparatus for purifying an organic substance having a high melting point according to the present invention, which is a cylindrical heating unit A, a collection unit B, and a collection unit connected in series. It consists of part C.

  The heating part A has a heating chamber formed therein, and further includes a metallic material cylindrical body 1 that generates heat by an induced current, an induction coil 6 that surrounds the outer periphery of the cylindrical body, a thermocouple 4 and a temperature controller 8. I have. The induction coil 6 is connected to an AC power source, and the supplied power is controlled by a temperature regulator 8 connected to the thermocouple 4. The shape of the cylindrical body 1 is not particularly limited, but when it is installed horizontally, it may be a semi-cylindrical shape in which the cylinder is divided in half in the length direction, and the flat surface may be the lower surface. It is preferable because a solid material as a raw material can be easily charged and installed at a predetermined position. Further, the cylindrical body 1 may be composed of one layer of metal material, may be composed of two or more layers of metal material, or may be composed of at least one layer of metal material and another non-metal material. There is no problem. However, at least one layer needs to be a metal material that generates heat by an induced current, and is preferably a magnetic material.

  The solid material to be purified may be continuously charged into the heating chamber in the form of powder or the like, but it is convenient to intermittently load it on a boat or the like. When the solid material is easily deteriorated by heat, it can be charged continuously or intermittently in small amounts.

  Heating is performed by supplying electric power, and the electric power supply amount is controlled so as to reach the purification temperature in the shortest possible time. Since reducing the heat capacity is also effective for increasing the rate of temperature increase, it is advantageous not to increase the diameter of the cylindrical body 1 or increase the thickness more than necessary.

  On the downstream side of the heating unit A, a collecting unit that is kept at a lower temperature is provided. In addition, an intermediate zone maintained at an intermediate temperature can be provided between the heating unit A and the collection unit as necessary. This collecting part preferably has a plurality of zones, and at least one zone is capable of induction heating. In the drawing, a zone of the collection part B that is capable of induction heating and a zone of the collection part C that is not so are provided, and the collection part B is connected to the heating part A. The collecting part B is composed of a cylindrical body 2 made of a metal material, an induction coil 7 surrounding the outer periphery thereof, a thermocouple 5 and a temperature controller 9, and is capable of induction heating. As for the heating structure of the collection part B, the same structure as the heating part A can be applied. However, when the material to be collected is liquid, a weir along an appropriate temperature distribution is provided, and a predetermined temperature is set. It is also effective to classify the condensed matter in the range. The shape of the weir may be a shape that does not mix the condensate in a predetermined range and the condensate in another range, but a shape such as a ring-shaped partition wall is preferable. It is also effective to provide an extraction valve at the bottom. If the material to be collected once becomes liquid and then becomes solid in the collecting part, a valve for extraction or the like is unnecessary. A collection unit C is connected to the downstream side of the collection unit B.

  In the drawing, the collecting portion C is formed of a cylindrical body 3, but the outer periphery thereof may be kept warm, cooled, or in contact with air. Further, unlike the drawing, it may be placed upstream of the collection part B. Moreover, although the collection part B made inductive heating may be 1 step | paragraph or 2 steps | paragraphs or more, when there is one kind of substance which should be collected as a target object, it collects it Only the portion to be heated may be induction heated. The collection part B for induction heating is controlled in temperature so that the substance to be collected is collected with a certain purity or more, and has a zone of a predetermined length maintained at a constant temperature. . That is, there are two or more zones in which the temperature is made almost constant by induction heating between the heating part and the collection part, and the temperature is gradually lowered toward the downstream part. The outlet of the collecting part on the most downstream side is connected to the vacuum pump 11 via the trap 10.

  Hereinafter, a method for purifying a high-melting-point organic substance containing impurities using the above-described purification apparatus will be described. For convenience of explanation, the case where the purified material contains the target substance and impurities having a lower boiling point will be described.

  In the refining apparatus of FIG. 1, when an organic material as a raw material is charged into a heating chamber and an AC power source is passed from an AC power source to an induction coil 6, the cylindrical body 1 made of the metal material of the heating unit A is electromagnetically heated. Heat is generated and the charged raw material reaches the boiling temperature through melting. The temperature control of the cylindrical body 1 is to maintain the set temperature by measuring the temperature of the heating part A with the thermocouple 4, turning on / off the AC power source with the temperature controller 8, or controlling the inverter. Can do. The target substance and impurities having a low boiling point in the charged raw material melted in the heating part A are moved to the collecting part B as gas by the suction force of the vacuum pump 11 located behind the collecting part C.

The gas moved to the collection part B is cooled by the cylindrical body 2 held at a temperature not higher than the dew point temperature of the target substance and not lower than the dew point temperature of the contained low-boiling impurities, and is transferred to the inner wall of the cylindrical body 2. Only the target substance is condensed and collected. Heat generation and temperature control in the collection part B can be performed in the same manner as in the heating part A. This temperature is higher than the dew point of the impurity and is preferably as low as possible. However, if there are a large number of impurities and impurities that allow a slight amount of contamination, the temperature is set lower. It is also possible.
Usually, it is collected as a liquid, but if the temperature is sufficiently low, it can be recovered in a solid state. However, making the temperature sufficiently low may be disadvantageous in terms of improving purity. It is also advantageous to condense with liquid, exist in liquid during operation, cool to solid after operation, and scrape. If the condensation temperature contains impurities in the vicinity, it is preferable to collect in the liquid phase, and it is preferable to provide a multistage with the weirs and partition walls in the collection part for collecting the target compound. . If there is no such impurity, it may be quickly collected as a solid.

  In the refining apparatus of the present invention, the cylindrical bodies 1 and 2 constituting the heating part A and the collecting part B are heated by electromagnetic induction heating, so that the entire cylindrical metal material constituting the heating parts A and B is made of metal material. There is a need to make two or more layers, and one or more layers must be made of a metal material, and at least one of these layers is preferably made of a magnetic metal material. As such a metal magnetic material, iron is generally used, but stainless steel can also be used from the viewpoint of heat resistance and corrosion resistance.

  The induction coils 6 and 7 and the temperature regulators 8 and 9 used for electromagnetic induction heating of the cylindrical bodies 1 and 2 may be those used in conventionally known electromagnetic induction heating devices. In order to heat the cylindrical bodies 1 and 2 uniformly, it is important that the induction coils 6 and 7 are installed so as to surround the outer periphery thereof with a predetermined length.

  In this way, by heating the cylindrical bodies 1 and 2 by electromagnetic induction heating, the entire fixed zone of the heating part A and the collecting part B can be heated uniformly, for example, the temperature is raised from room temperature to 400 ° C. However, the heating rate is as high as several minutes to 30 minutes, and the accuracy of temperature control can be increased.

  In the trapping part B, only the target substance is aggregated and trapped, and the impurities in the raw material are allowed to pass in a gaseous state, and the impurities are aggregated and trapped in the trapping part C directly connected to the trapping part B. . Therefore, the collection unit C may be cooled to a predetermined temperature, for example, about room temperature, by air cooling or liquid cooling that is normally performed.

  Between these heating section A, collection section B and collection section C, providing a temperature gradient in which the temperature decreases substantially stepwise or continuously toward the downstream side increases the target purity. Necessary to increase the recovery yield. The step shape means that there are a plurality of zones having a substantially constant temperature in the gas flow direction in the purifier, and does not exclude having a zone in which the temperature continuously decreases. The length of the zone having a substantially constant temperature is determined from the viewpoint of securing a collection capacity having a constant composition.

  In order to increase the purification rate, it is preferable to increase the evaporation rate of the target product by reducing the pressure in the purification apparatus, and it is preferable to provide a vacuum pump 11 or the like on the end side of the collection part C as shown in FIG. . In some cases, an accompanying gas such as nitrogen gas is supplied from the inlet direction of the heating unit A, and the purification rate can be increased by the accompanying gas.

  In the above description of the purification method, the case where the target substance and impurities having a lower boiling point are contained as components has been described. However, when the impurity has a boiling point higher than that of the target substance, it is first collected. Impurities are collected in the part B, and then the target substance is collected in the collecting part C. However, the collection unit for collecting the target substance is preferably a collection unit capable of induction heating, and the collection unit for collecting impurities may not be induction-heatable.

  In the above embodiment, the heating unit A and the collection unit B have two different temperature zones, that is, one collection unit B that generates heat by electromagnetic induction heating and adjusts the temperature, and normal cooling. Although the example of the refinement | purification apparatus provided with the one collection part C by a method was demonstrated, this invention is not limited to this.

  For example, there are two collectors that adjust the temperature by generating heat with electromagnetic induction adjusted to different temperature zones, such as the collector B having two different temperature zones such as B1 and B2. There may be provided one or more collectors having a total of three or more different temperature zones. In the case of the above example as well, three different temperatures are provided between the heating part A, the collecting parts B1, B2 and the collecting part C by providing a temperature gradient in which the temperature decreases substantially stepwise toward the downstream side. In the collecting part having the temperature zone, each component in the gas can be shrunk according to its melting point. In some cases, it is possible to omit the collection part C and to reduce other components such as the target substance and impurities only by the collection part that generates heat by two or more electromagnetic induction types and adjusts the temperature. In order not to mix with the liquid condensed in other parts, an inner cylinder provided with a partition wall or a weir may be used.

  The diameter and length of the cylindrical body used in the purification apparatus are appropriately determined depending on the type of organic material and the processing amount, but the apparatus of the present invention can process from a small amount to a large amount, the boiling point is 300 ° C. or higher, the melting point Is useful for organic materials above 200 ° C. Furthermore, by reducing the pressure of the purification apparatus, processing at a low temperature is possible, which is suitable for purification of unstable substances.

Hereinafter, the present invention will be specifically described based on examples.
Example 1
N, having an HPLC purity of 94%, used as an amount of hole transport material in an organic EL device obtained by reacting 4,4′-diiodobiphenyl, phenyl-1-naphthylamine, potassium carbonate and copper powder in nitrobenzene. N`-di- (naphthalen-1-yl) -N, N'-diphenyl-benzidine (hereinafter referred to as NPB) was purified using the apparatus shown in FIG. For the heating part A and the collecting parts B and C, a stainless steel tube having a diameter of 60 mm and a length of 1000 mm was commonly used. The AC power supply was 200 V and 60 Hz, and inverter control was used for the temperature controllers 6 and 7.
Place the NPB 10g in the heating chamber in a 50mmφ, 100mm long glass boat that has been halved in the length direction. The temperature of the heating part A is 330 ° C, the temperature of the collecting part B is 300 ° C, and the collecting part. The outer periphery of C was kept at substantially room temperature by contacting with air at room temperature, and the inside of the purifier was reduced to 0.1 Torr by the vacuum pump 11. The NPB recovered from the collection part B was 5.6 g, and its HPLC purity was 99%. After the operation, the temperature of the collection part B was lowered and NPB was recovered as a solid.

Example 2
In place of the apparatus of Example 1, a 300 mmφ and 500 mm long carbon steel pipe halved in the length direction is used for the heating part A, and a 100 mmφ and 500 mm long carbon steel pipe is used for the collecting part B. For the collecting part C, a stainless steel tube having a diameter of 100 mmφ and a length of 500 mm was used. The heating part A and the collection parts B and C were directly connected via a flange. 100 g of the same NPB as used in Example 1 was placed in the heating part A on a glass bat having a length of 200 mm, a width of 250 mm, and a height of 20 mm, the temperature of the heating part A was 380 ° C., and the temperature of the collecting part B 280 ° C., the outer circumference of the collection unit 3 was kept in contact with air at room temperature and kept at substantially room temperature, and the inside of the purifier was depressurized to 0.2 Torr by the vacuum pump 11. NPB recovered from the collection part B was 50.7 g, and its HPLC purity was 99%.

Comparative Example 1
Purification of the same HPLC purity of 94% NPB 2.0g used in Example 6 using the apparatus comprising the glass outer cylinder 13 and the glass inner cylinder collector 14 shown in FIG. went. The collection unit 14 is cooled by the supplied nitrogen gas. The raw material compound was charged into the bottom of the glass outer cylinder 13.
The inside of the system is reduced to 2.0 Torr by the vacuum pump 17 through the cooling trap 16, the temperature of the heating unit 12 controlled by the temperature controller 15 is set to 390 ° C., and NPB at the bottom of the glass outer cylinder 13 is evaporated. This was condensed and solidified on the glass outer wall of the collection part 14 and collected. The collected NPB was 1.4 g and the HPLC purity was 96%.

Effect of the invention

  According to the purification method of the present invention, a high-boiling-point, high-melting-point organic material containing impurities is purified by electromagnetic induction heating, and only a target substance is selectively selected at a collection part held at a specific temperature by electromagnetic induction. By collecting, it becomes possible to obtain a high-purity product with a high yield. In addition, the refining apparatus can handle from a small amount to a large amount, and the accuracy of temperature control is high, and the refining time can be shortened, so that the refining apparatus is highly productive.

  Sectional drawing which shows an example of the apparatus for enforcing the purification method of this invention   Sectional drawing which shows an example of the refinement | purification apparatus mentioned as a comparative example

A: Heating part
B, C: Collection unit 1, 2, 3: Tubular body 4, 5: Thermocouple 6, 7: Induction coil 8, 9: Temperature controller 10: Cooling trap 11: Vacuum pump 12: Heating unit 13: Glass outer cylinder 14: Glass inner cylinder

Claims (2)

It has an evaporating part that evaporates and evaporates the high melting point organic materials arranged in the lateral direction, and a collecting part that condenses and collects the evaporated gas, and the temperature of the collecting part is substantially stepped or continuous toward the downstream side. And at least a part of the evaporation part and the collection part are made of a material capable of electromagnetic induction heating, and the outer periphery thereof has an induction coil for generating heat by the electromagnetic induction method, Furthermore, the internal distillation material that contacts the high melting point organic material is made of a material selected from metals, glass, ceramics, and fluororesin inert to the high melting point organic material. An electroluminescent material as a melting point organic material was charged into the evaporation section, heated and melted and evaporated, and the evaporated gas was introduced into a collection section having a condensation zone maintained in a predetermined temperature range and purified from the zone. Take organic materials Distillation purification method comprising Succoth.
The distillation purification method according to claim 1 , wherein one or more weirs are provided in the collecting part .

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