WO2002053250A1

WO2002053250A1 - Distillation purification method and device for high-melting organic materials

Info

Publication number: WO2002053250A1
Application number: PCT/JP2001/011191
Authority: WO
Inventors: Shinji Matsuo; Kazuo Ishii; Hiroshi Miyazaki
Original assignee: Nippon Steel Chemical Co., Ltd.
Priority date: 2000-12-28
Filing date: 2001-12-20
Publication date: 2002-07-11
Also published as: JP2002200401A; JP5248721B2

Abstract

A method of distilling and purifying high-melting materials while preventing corrosion of the device, contamination of the distillate and degeneration; and a device used therefor. The distillation purification device comprises an evaporating section (A) for evaporating high-melting organic materials subsequently to melting thereof, and collecting sections (B, C) for condensing and collecting the evaporated gas, the temperature of the collecting sections being substantially stepwise or continuously decreasing toward the downstream side, at least the evaporating section and part of the collecting section being made of a material that can be heated through electromagnetic induction by an dielectric coil, the inner surface of the device contacting high-melting organic materials being made of a material that is inert to such high-melting organic materials. Effecting distillation using this distillation purification device makes it possible to selectively collect only the intended substance in the collecting sections held at a specific temperature by electromagnetic induction; thus, a product of high purity can be obtained at a high yield.

Description

Description Method and apparatus for distillation purification of high melting point organic material

TECHNICAL FIELD The present invention relates to a method and an apparatus for purifying a high melting point organic material by distillation. BACKGROUND ART Generally, techniques such as recrystallization, adsorption separation, distillation, and sublimation are used to purify organic materials.

Purification using recrystallization is a purification method that uses the difference in solubility of substances depending on the temperature.However, it is difficult to select an available solvent, the solubility difference due to temperature is small, and even if there is a difference in solubility, the solubility itself is low. There may be problems such as requiring a large amount of solvent to purify a small and specified amount.

On the other hand, when using adsorptive separation, it is difficult to select an adsorbent.High-melting-point organic materials generally have low solubility in general-purpose organic solvents in general, and as a result, they are used as a mobile bed. Requires a large amount of solvent to be used.

Furthermore, in the purification using these solvents, it is necessary to remove the used solvent.However, depending on the material, mixed crystals with solvent molecules may be formed, and it is necessary to consider a trace amount of residue. . This has led to a high degree of purification. This is problematic for the required materials.

In distillation purification, it is not necessary to consider the above problems as long as thermal stability can be ensured. However, in the case of high melting point materials, blockage in the rectification section for improving the distillation accuracy and the piping for guiding the purified product to the collection section became a serious problem. It becomes necessary to take heat insulation measures such as by uniformly heating the material and the entire pipe, which makes the equipment bloated and equipment maintenance difficult.

Molecular distillation is a technique that is relatively unlikely to cause the above problems and is widely used. However, if the target raw material contains impurities with close boiling points, it is difficult to condense and collect only the target substance because it does not have a rectification section for precise separation control. is there.

It is known that sublimable materials can be purified using an apparatus similar to molecular distillation, and a method for improving this is disclosed in JP-A No. 12-93701, etc. In the first place, sublimable materials are scarce in general in organic compounds in general, and the usable range is limited. DISCLOSURE OF THE INVENTION Accordingly, an object of the present invention is to heat a trace amount to a large amount of a feedstock uniformly and in a short time, and to control the heating temperature and the collection temperature with high precision, thereby making it possible to purify a general method. It is an object of the present invention to provide a method and an apparatus for efficiently distilling and refining a high melting point organic material which is difficult to perform.

The present invention has an evaporating section for melting and evaporating the high-melting point organic material and a collecting section for condensing and collecting the vaporized gas, and the temperature of the collecting section is substantially stepwise toward the downstream side. At least a part of the evaporator and the collector is made of a material that can be heated by electromagnetic induction. It is a distillation purification device composed of a material that is inert to the organic material having a melting point. As a material inert to a high melting point organic material in a molten state, a material selected from metals, glass, ceramics, and fluororesins is preferably exemplified. It is also advantageous to provide one or more weirs in the collection area.

Further, the present invention has a heating unit and a collecting unit in which at least one layer is made of a metal material, and at least a part of the outer periphery thereof has an induction coil for generating heat by an electromagnetic induction method. This is a distillation purification device in which the collection section is provided with a temperature gradient such that the temperature decreases substantially stepwise or continuously toward the downstream side.

In addition, the present invention provides a distillation and purification apparatus in which a high-melting-point organic material is charged into an evaporator, heated, melted and evaporated, and the vaporized gas is collected in a collector having a condensing zone maintained in a predetermined temperature range. This is a distillation purification method for recovering purified organic material from the zone after introduction.

Although the organic material to be purified in the present invention is not particularly limited, it has a high melting point, which is difficult to purify by a general method, and is particularly effective for a crystalline solid material in which a crystal takes in a solvent or the like to become a single crystal. Yes, for example, it is effective for solid materials such as electronic materials and optical materials, in which trace impurities or differences in crystal form or deformation often have a large effect. Examples of such a material include an electroluminescent device (EL) material, a semiconductor device material, and the like, which are suitable for an organic EL device material. The electromagnetic induction heating device only needs to generate heat by passing a low-frequency AC current through a coil disposed around a conductive metal material. The frequency of the current is generally 50 to 500 Hz, and a commercial frequency can be used.

In the purification device 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 unit and the collecting unit are preferably cylindrical, but the diameter and the cross-sectional shape may be different in the middle. According to the direction of flow of the organic material to be purified, it has a heating section on the upstream side and a collecting section on the downstream side. At least a part of the heating unit and the collecting unit is made of a conductive metal material so that electromagnetic induction heating can be performed, and a coil is arranged around the conductive metal material. FIG. 1 is a cross-sectional view showing an example of an apparatus for carrying out the purification method of the present invention, which comprises a cylindrical sublimation section A, a collection section B, and a collection section C, each of which is connected in series. FIG. 2 is a cross-sectional view showing an example of a conventional purification device. BEST MODE FOR CARRYING OUT THE INVENTION 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. It consists of part A, collection part B and collection part C.

Heating section A has a heating chamber inside, and generates heat by induction current. A cylindrical member 1 made of a metallic material, an induction coil 6 surrounding the outer periphery of the cylindrical member, a heat transfer device 4 and a temperature controller 8. The induction coil 6 is connected to an AC power supply, and the power supply is controlled by a temperature controller 8 connected to the thermocouple 4. The shape of the cylindrical body 1 is not particularly limited, but when it is installed horizontally, it has a semi-cylindrical shape such that the cylinder is divided in half in a length direction, and a flat surface is used as a lower surface. This is preferable because a solid material as a raw material can be easily charged and installed at a predetermined position. Further, whether the cylindrical body 1 is composed of one layer of metal material, or composed of two or more layers of metal material, it is composed of at least one layer of metal material and another nonmetallic material. No problem. However, at least one of the layers must be made of a metal material that generates heat by induced current, and is preferably a magnetic material.

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

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

On the downstream side of the heating unit A, a collecting unit that keeps the temperature lower than that 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 needed. The trap preferably has a plurality of zones, and at least one zone is capable of induction heating. In the drawing, the zone of the collector B where induction heating is possible, and not A zone for the collecting section C is provided, and the collecting section B is connected to the heating section A. The collecting portion B is composed of a cylindrical body 2 made of a metallic 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 the heating structure of the collecting section B, the same structure as that of the heating section A can be applied.However, when the material to be collected is in a liquid state, a weir along an appropriate temperature distribution is provided and a predetermined temperature is provided. It is also effective to classify those condensed in a range. The shape of the weir may be a shape in which the condensed liquid in the predetermined range and the condensed liquid in the other range are not mixed, but a shape such as a ring-shaped partition wall is preferable. It is also effective to provide a withdrawal valve at the bottom. If the material to be collected once becomes liquid and then becomes solid at the collecting part, a valve or the like for withdrawal is unnecessary. Further, a collecting section C is connected downstream of the collecting section B.

In the drawing, the collecting portion C is formed of the cylindrical body 3, but the outer periphery thereof may be kept warm, cooled, or come into contact with air. Also, unlike the drawing, it may be placed upstream of the collecting section B. The collection section B, which can be induction-heated, may have one stage or two or more stages, but if only one substance is to be collected as the target substance, it is collected. Only the portion to be collected may be capable of induction heating. The collecting section B for induction heating is controlled in temperature so that the substance to be collected is collected with a certain degree of purity, and has a zone of a predetermined length maintained at a certain temperature. You. In other words, there are two or more zones where the temperature is almost constant by induction heating between the heating part and the trapping part, and the temperature is gradually decreased toward the downstream part. The outlet of the most downstream collecting section is connected to the vacuum pump 11 via the trap 10.

In the following, high-melting organic substances containing impurities are The purification method will be described. For convenience of explanation, the case where the refined raw material contains the target substance and impurities having a lower boiling point will be described.

In the refining device shown in Fig. 1, an organic material, which is a raw material, is charged into a heating chamber, and an AC power supply is passed from an AC power supply to an induction coil 6, so that a cylindrical body 1 made of a metal material of a heating section A is electromagnetically induced. Heat is generated by heating, and the charge reaches the boiling temperature through melting. The temperature of the cylindrical body 1 is controlled by measuring the temperature of the heating section A with the thermocouple 4, turning the AC power on and off with the temperature controller 8, and controlling the inverter by controlling the inverter. Can be held. The target substance and impurities having a low boiling point in the charged raw material melted in the heating section A are transferred to the collecting section B as gas by the suction force of the vacuum pump 11 behind the collecting section C.

The gas transferred to the collecting section B is cooled by the cylindrical body 2 maintained at a temperature equal to or lower than the dew point temperature of the target substance and equal to or higher than the dew point temperature of the contained low-boiling impurities, and the inner wall of the cylindrical body 2 Only the target substance is condensed and collected. The heat generation in the trapping section B and its temperature control can be performed in the same manner as in the heating section A. It is desirable that this temperature be higher than the dew point of the impurities and be as low as possible.However, if the impurities contain a large number of impurities and a small amount of impurities can be tolerated, lower the temperature further. It is also possible to set.

It is usually collected as a liquid, but if the temperature is lowered sufficiently, it can be recovered as a solid. However, lowering the temperature sufficiently can be disadvantageous in terms of improving purity. It is also advantageous to condense with a liquid, exist as a liquid during operation, and cool down after operation to form a solid, which is then discharged. If the condensation temperature contains impurities that are nearby, It is preferable to collect in the liquid phase, and it is preferable that the collecting section for collecting the target compound has a multistage structure provided with the above-mentioned barrier wall. If there is no such impurity, it may be promptly collected as a solid.

In the refining apparatus of the present invention, since the tubular body 1.2 constituting the heating section A and the collecting section B generates heat by electromagnetic induction heating, the entire tubular metallic material constituting the tubular body 1.2 is made of a metallic material. It is necessary that there be, or to be formed of two or more layers, and one or more layers be made of a metal material, but it is preferable that at least one of the layers is made of a magnetic metal material. Iron is generally used as such a metal magnetic material, but stainless steel can be used from the viewpoint of heat resistance and corrosion resistance.

The induction coil 67 and the temperature controllers 8, 9 used for heating the cylindrical bodies 1 and 2 by electromagnetic induction may be those used in a conventionally known electromagnetic induction heating device. In order to heat the cylindrical bodies 1 and 2 uniformly, it is important that the induction coils 6 and 7 be installed so as to surround the outer circumference of the cylindrical bodies 1 and 2 by a predetermined length. By causing the bodies 1 and 2 to generate heat, it is possible to uniformly generate heat in a certain zone of the heating section A and the collecting section B. For example, it takes several minutes to raise the temperature from room temperature to 400 ° C. The heating rate is high, about 30 minutes, and the accuracy of temperature control can be increased.

In the collecting section B, only the target substance is agglomerated and captured, and the impurities in the raw material pass through in a gaseous state, and the impurities are agglomerated in the collecting section C directly connected to the collecting section B. , To capture. Therefore, the collecting section C may be cooled to a predetermined temperature, for example, about room temperature, by air cooling or liquid cooling which is usually performed.

Between these heating section A, collection section B and collection section C, It is necessary to provide a temperature gradient in which the temperature decreases almost stepwise or continuously, in order to increase the target purity and increase the recovery yield. Note that the step-like shape means that there are a plurality of zones having a substantially constant temperature in the gas flow direction in the refining device, and does not exclude having a zone where the temperature continuously decreases. The length of the zone where the temperature is almost constant is determined from the viewpoint of securing a trapping capacity of 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 inside the purification device.As shown in Fig. 1, a vacuum pump 11 etc. is installed at the end of the collecting section C. It is good to provide. In some cases, an accompanying gas such as nitrogen gas is supplied from the entrance direction of the heating section A, and the refining speed can be increased by the accompanying gas.

In the above description of the purification method, a case was described in which the target substance and an impurity having a lower boiling point were contained as components, but if the impurity has a higher boiling point than the target substance, First, the trapping section B traps impurities, and then the trapping section C traps the target substance. However, the collecting section for collecting the target substance may be a collecting section capable of induction heating, and the collecting section for collecting impurities may not be capable of induction heating. Further, 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 using an electromagnetic induction heating method and controls the temperature, Although an example of the purification apparatus provided with one collection unit C by the cooling method has been described, the present invention is not limited to this.

For example, a trap that adjusts the temperature by generating heat with an electromagnetic induction type that is adjusted to different temperature zones, such as a case where the collecting section B has two different temperature zones such as Bl and B2. There are two or more junctions, a total of three or more different temperatures It may have a collecting section having a degree zone. Also in the case of the above example, by providing a temperature gradient between the heating section A and the collection sections Bl and B2 and the collection section C, the temperature decreases almost stepwise toward the downstream side. In the trapping section having three different temperature zones, each component in the gas can be reduced according to its melting point. In some cases, it is possible to omit the collecting section C and to decompose the target substance and other components such as impurities only by the collecting section that generates heat by two or more electromagnetic induction methods and controls the temperature. To avoid mixing with liquid condensed in other parts, use an inner cylinder with a partition wall or weir

The diameter and length of the cylindrical body used in the refining device are determined as appropriate depending on the type and amount of the organic material, but the device of the present invention can process from a small amount to a large amount, and has a boiling point of 300 ° C. As described above, it is useful for organic materials having a melting point of 200 ° C or more. Furthermore, by reducing the pressure of the purification equipment, it is possible to process at low temperature, which is suitable for purification of unstable substances. 'Examples Hereinafter, the present invention will be specifically described based on examples.

Example 1

HPLC purity used as a hole transport material in an organic EL device obtained by reacting 4,4-jadodbiphenyl, phenyl-11-naphthylamine, potassium carbonate and copper powder in nitrobenzene 94% of, -di- (naphthalen-1-yl) _Ν, Ν'-diphenyl-benzidine (hereinafter referred to as ΝΡΒ) was purified using the apparatus shown in Fig. 1. Heating section Α, collecting section B, C, 60

10 91) A stainless steel tube of mm φ and length of 100 mm was commonly used. The AC power supply was 200 V, 60 Hz, and the temperature controllers 6 and 7 used inverter control.

Force [I Place the heat chamber in a 50 mm した, 100 mm long glass boat with 50 g of NPB halved in the lengthwise direction and load it in the heat chamber. C, the temperature of the collecting section B is set at 300 ° C. The outer periphery of the collecting section C is brought into contact with air at room temperature to maintain the room temperature almost, and the inside of the purification device is reduced by the vacuum pump 11. Was reduced to 0.1 Torr. The amount of NPB recovered from the collecting part B was 5.6 g, and its HPLC purity was 99%. After the operation was completed, the temperature of the collecting section B was lowered, and NPB was recovered as a solid.

Example 2

In place of the apparatus of Example 1, a heating section A was made of a carbon coconut pipe having a length of 300 ram _{N and a} length of 500 ram, and a collecting section B was made of 100 ram. A carbon steel tube having a diameter of 0 mm and a length of 50 ° mm was used, and a stainless steel tube having a length of 100 mm (i) and a length of 500 ram was used for the collecting section C. Heating section A and collection sections B and C were directly connected via a flange. The same NPB 100 g as used in Example 1 was placed in heating section A by placing it on a glass knot having a length of 200 mm, a width of 250 mm, and a height of 2 Omm. Temperature at 380 ° C, the temperature of the collecting section B at 280 ° C, the outer periphery of the collecting section 3 is kept in contact with air at room temperature and maintained at almost room temperature, and the vacuum pump 11 The pressure inside the purification device was reduced to 0.2 Torr. The amount of NPB recovered from the collecting part B was 50.7 g, and its HPLC purity was 99%.

Comparative Example 1

As shown in FIG. 2, 2.0 g of NPB having an HPLC purity of 94% similar to that used in Example 1 was constituted by a glass outer cylinder 13 and a glass inner cylinder collection section 14 shown in FIG.

11 Corrected ^ Paper (Rule ₉₁ ) Purification was performed using an apparatus. The collecting section 14 is cooled by the supplied nitrogen gas. The raw material compound was charged into the bottom of a glass outer cylinder 13. The pressure inside the system was reduced to 2.0 Torr by the vacuum pump 17 via the cooling trap 16, and the temperature of the heating section 12, which was temperature-controlled by the temperature controller 15, was set to 39 ° C. The NPB at the bottom of the outer cylinder 13 was evaporated, and the NPB was condensed and solidified on the outer glass wall of the collection unit 14 and collected. The collected NPB was 1.4 g and the HPLC purity was 96%. INDUSTRIAL APPLICABILITY 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 is collected by a collection unit kept at a specific temperature by electromagnetic induction. By selectively collecting only the target substances, it becomes possible to obtain high-purity products at high yields. In addition, the purification equipment can handle small to large quantities, and the accuracy of temperature control is high, and the purification time can be shortened, resulting in high productivity of the purification equipment.

Claims

' The scope of the claims

(1) Evaporator for melting and evaporating the high-melting organic material, and a collector for condensing and collecting evaporative gas.The temperature of the collector is reduced stepwise or continuously toward the downstream side. In addition, at least a part of the evaporating part and the trapping part is made of a material that can be heated by electromagnetic induction, and furthermore, the inner material of the device that comes into contact with the organic material having a high melting point is in contact with the organic material having the high melting point. Distillation and purification apparatus characterized by being made of inert material. '

(2) The distillation and refining apparatus according to claim 1, wherein the material inert to the high melting point organic material is a material selected from metals, glass, ceramics, and fluorine resin.

(3) The distillation purification device according to claim 1, wherein one or more weirs are provided in the collecting part.

(4) At least one layer of the heating unit is made of a metal material in a refining apparatus having a heating unit and a collecting unit, and an outer periphery of the heating unit is provided with an induction coil for generating heat by electromagnetic induction. A collecting part capable of having a plurality of zones with different temperatures is provided on the downstream side of the part, and at least one layer of one or more of the zones is made of a magnetic metal material, and the outer periphery thereof is provided with electromagnetic induction. And an induction coil for generating heat by a formula, wherein a temperature gradient is provided in the trapping section so that the temperature decreases substantially stepwise or continuously toward the downstream side. Purification equipment.

(5) A high-melting-point organic material is charged into the evaporator, heated and melted and evaporated in the distillation purifier according to any one of claims 1 to 4, and the evaporated gas is condensed in a predetermined temperature range. Purification from the zone by introducing into the collection section having a zone A distillation purification method characterized by taking out the used organic material.

(6) (After correction) The sublimation purification method according to claim 5, wherein the high melting point organic material is an organic compound used as an organic EL element material.

14 Corrected Form (Rule 91)