JP6650478B2 - Organic solvent purification apparatus and purification method - Google Patents

Description

  The present invention relates to an apparatus and a method for purifying an organic solvent.

  Generally, a purification apparatus and a purification method for purifying an organic solvent by distillation are known.

  For example, Patent Literature 1 discloses a distillation purification method and a distillation purification apparatus for a liquid containing low volatile impurities such as metal components. Patent Document 2 discloses a method for purifying isopropyl alcohol containing As, B, Se, and Ge.

JP 2001-092001 A JP-A-10-109948

  2. Description of the Related Art In recent years, with the development of analysis techniques in an ultra-trace area, such as inductively coupled plasma mass spectrometry (ICP-MS), there has been a demand for even higher purity of a diluting organic solvent used for analysis. Further, organic solvents used in the production of electronic equipment and resist photosensitizers are also required to have higher purity.

  However, in the distillation purification method and the distillation purification device of Patent Document 1, although the concentration of the low-volatile impurities contained in the liquid can be in the ppb order, it cannot be in the ppt order.

  In the purification method of Patent Document 2, although the concentration of the metal contained in isopropyl alcohol can be in the order of ppt, the target metal is limited to As, B, Se, and Ge. Not applicable to metal.

  An object of one embodiment of the present invention is to mainly provide an organic solvent refining apparatus and a refining method capable of reducing the concentration of each metal contained in the organic solvent to 10 ppt or less.

  The present inventor has proposed that the contact portion of the evaporator, the condenser and the recovery device with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more, so that the concentration of each metal contained in the organic solvent can be improved. Can be reduced to 10 ppt or less, and the present invention has been completed.

That is, the present invention includes the following inventions [1] to [8].
[1] An evaporator that heats and vaporizes an organic solvent, a condenser that has a cooling unit that cools and condenses the vaporized organic solvent, and a recovery device that recovers the condensed organic solvent; An organic solvent refining apparatus, wherein a contact portion of the vessel, the condenser, and the collector with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more.
[2] The condenser has a distillation column unit, and the distillation column unit includes a droplet arrival prevention member that prevents droplets of the organic solvent before purification from reaching the cooling unit. [1] An organic solvent refining apparatus according to claim 1.
[3] The apparatus for purifying an organic solvent according to [1] or [2], wherein the evaporator includes an inert gas supply port for supplying an inert gas into the evaporator.
[4] an evaporation step of heating and vaporizing the organic solvent in the evaporator, a condensing step of cooling and condensing the vaporized organic solvent using a condenser having a cooling unit, and a collector for collecting the condensed organic solvent. A refining step of refining the organic solvent, wherein at least a part of the evaporator, the condenser and the recovering device that is in contact with the organic solvent is quartz or silicon carbide having a purity of at least 99.95% by weight. A method for purifying an organic solvent, comprising:
[5] The condenser has a distillation column unit provided with a droplet arrival prevention member, and prevents the droplets of the organic solvent before purification from reaching the cooling unit by the droplet arrival prevention member. The method for purifying an organic solvent according to [4].
[6] The method for purifying an organic solvent according to [4] or [5], wherein in the evaporating step, an inert gas is supplied to the evaporator.
[7] The method for purifying an organic solvent according to any one of [4] to [6], further comprising a washing step of washing the evaporator, the condenser, and the collector with a mixed acid.
[8] An organic solvent in which the concentration of each metal contained as an impurity is 10 ppt or less.

  According to one embodiment of the present invention, it is possible to provide an organic solvent refining apparatus and a refining method capable of reducing the concentration of each metal contained in the organic solvent to 10 ppt or less.

It is a front view showing the schematic structure of the refining device concerning one embodiment of the present invention. It is a front view which shows the cover body of the evaporator with which a refinement | purification apparatus is provided, and a condenser. (A) is a top view which shows the main body of an evaporator, (b) is sectional drawing along the AA line of (a).

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to this, and various changes can be made within the described range, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also described. It is included in the technical scope of the present invention. In this specification, unless otherwise specified, “A to B” representing a numerical range means “A or more and B or less”. Also, “mass” and “weight” are considered to be synonyms.

(Organic solvent)
The organic solvent to be purified in one embodiment of the present invention is not particularly limited, but includes, for example, alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and propylene glycol; aliphatic hydrocarbons such as hexane and heptane; Halogenated hydrocarbons such as water, chloroform and the like; Aromatic hydrocarbons such as toluene and pyridine; Esters such as ethyl acetate and γ-butyl lactone; Ketones such as acetone and methyl amyl ketone; 1,4-dioxane; tetrahydrofuran; Examples include ether (PGE), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PGMEA), acetonitrile, N, N-dimethylformamide, and mixtures thereof.

(impurities)
The concentration of the metal contained as an impurity in the organic solvent before purification is not particularly limited, but is preferably smaller, specifically, preferably 1 ppm or less, more preferably 0.1 ppm or less, More preferably, it is 1 ppb or less. Note that the above concentration refers to the concentration of the total amount when a plurality of types of metals are contained in the organic solvent.

  Examples of the metal that can be removed from the organic solvent include Li, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Rb, Sr, Y, Zr, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Ir, Pt, Au, Pb, and the like.

  Note that the refining apparatus and the refining method according to one embodiment of the present invention remove a metal contained as an impurity in the organic solvent to highly purify the organic solvent. Organic substances, such as high-boiling components and low-boiling components, which are impurities other than metals contained in the organic solvent are removed by a conventional purifying apparatus and a conventional purifying method.

(Purification equipment)
An apparatus for purifying an organic solvent according to an embodiment of the present invention includes an evaporator that heats and vaporizes the organic solvent, a condenser that has a cooling unit that cools and condenses the vaporized organic solvent, and a condensed organic solvent. A recovery device for recovering, and at least a contact portion of the evaporator, the condenser and the recovery device with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more.

  In the refining apparatus, the contact portion of the evaporator, the condenser, and the collector with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more. In the present invention, the term "organic solvent" in contact with the above-mentioned contact site refers to not only the organic solvent before purification but also any state such as a vaporized organic solvent (organic solvent gas) and a condensed (purified) organic solvent. Organic solvent.

  When the evaporator, the condenser and the recovery device are made of quartz, it is preferable that the evaporator, the condenser and the recovery device are also made of quartz in portions other than the contact portion with the organic solvent. Further, quartz is preferably synthetic quartz because of its higher purity.

  When the evaporator, the condenser and the collector are made of silicon carbide, it is difficult to process the silicon carbide into the shape of the evaporator, the condenser and the collector. Preferably, the above-mentioned contact sites of the evaporator, the condenser and the collector are coated with silicon carbide.

  Hereinafter, each member constituting the purification apparatus will be described with reference to FIGS. As shown in FIG. 1, a purifying apparatus 100 according to an embodiment of the present invention includes at least an evaporator 1, a condenser 2, and a collector 3, and the evaporator 1 and the condenser 2 are connected to each other. The condenser 2 and the recovery unit 3 are connected. The refining device 100 is used at a normal pressure in a clean environment such as a clean draft or a clean room. This can prevent the organic solvent after purification from being contaminated. When the evaporator 1, the condenser 2, and the recovery unit 3 are used for the first time, they are used after being washed with a mixed acid, as described in <Washing step> of [Purification method] described later.

<Evaporator 1>
The evaporator 1 heats and vaporizes the organic solvent before purification, and supplies the vaporized organic solvent to the condenser 2. The evaporator 1 includes a main body 10 into which an organic solvent before purification is injected, and a lid 20.

  The shape of the main body 10 of the evaporator 1 is preferably a cylindrical shape having a bottom surface, as shown in FIG. For example, to give a specific example, the shape and size of the main body 10 are a flat bottom surface, an inner diameter of 14 cm, a height of 9 cm, and a thickness of the bottom surface and side surfaces of 5 mm. Accordingly, the heating area and the liquid surface area can be relatively increased as compared with the amount of the injected organic solvent, so that the organic solvent can be vaporized more quickly.

  The main body 10 is used, for example, mounted on an electric heating type heating device (a so-called hot plate or heating heater). The temperature at which the organic solvent before the purification is heated is not particularly limited as long as it is a temperature equal to or higher than the boiling point of the organic solvent and lower than the boiling point of the metal to be removed. Further, it is preferable to end the heating in a state where the organic solvent before purification remains in the main body 10 of the evaporator 1.

  The amount of the organic solvent before purification to be injected into the main body 10 depends on the internal volume of the main body 10, but is preferably 1 L or less. Thereby, the amount of the droplets of the organic solvent before purification that have become droplets reaching the condenser 2 can be minimized.

  As shown in FIGS. 1 and 2, the lid 20 of the evaporator 1 has, for example, a disk shape, and mainly includes a lower part 23 fitted to the main body 10 and an upper part 22 which is the same as or slightly larger than the main body 10. It is configured. For example, as a specific example, the size of the lid 20 is such that the upper portion 22 has a diameter of 15 cm and a thickness of 6.5 mm, and the lower portion 23 has a diameter of 13.8 cm and a thickness of 6.5 mm. The lower portion 23 prevents the lid 20 from shifting due to contact with the inner wall of the main body 10 of the evaporator 1 and also prevents contaminants from being mixed. The contact portion of the lower portion 23 with the main body 10 is sufficiently airtight because the thickness of the main body 10 is sufficient.

  The lid 20 has an inert gas supply port 27 that supplies an inert gas to the evaporator 1. The shape of the inert gas supply port 27 is not particularly limited, but is preferably cylindrical. The opening of the inert gas supply pipe 28 extending from the inert gas supply port 27 is close to the bottom surface of the main body 10 so that the supplied inert gas does not immediately flow toward the condenser 2.

  The inert gas prevents bumping by stirring the organic solvent, and also increases the vaporization rate (purification rate) of the organic solvent, and quickly supplies the vaporized organic solvent to the condenser 2 to provide the combustion supporting gas ( In order to prevent accidents by discharging (atmosphere), the air is supplied to the evaporator 1 as needed, and is ventilated to an organic solvent before purification. Examples of the inert gas include nitrogen, helium, neon, argon, and a mixed gas thereof. The inert gas preferably has a high purity (99.999% or more). The inert gas is supplied from a gas cylinder of the inert gas through a pipe attached to the inert gas supply port 27. The supply speed of the inert gas is not particularly limited as long as the inside of the purification device 100 is maintained at normal pressure, so long as no droplet (droplet) of the organic solvent is generated. It is preferable that the inert gas be continuously supplied from the start of the purification of the organic solvent to the end of the purification. In addition, since the refining device can supply the inert gas to the evaporator 1 and stir the organic solvent, it is not necessary to provide a stirrer.

  The lid 20 of the evaporator 1 has a connecting portion 21 for inserting the connecting portion 50 of the condenser 2 on the evaporator 1 side. The connecting portion 21 is preferably located at the center of the lid 20 of the evaporator 1. The shape and size of the connecting portion 21 may be any shape as long as the connecting portion 50 of the condenser 2 can be stably fixed without a gap. For example, as a specific example, the connecting portion 21 has a cylindrical shape with an inner diameter of 2 cm so that the vaporized organic solvent can easily pass through. It is preferable that the connecting portion 21 and the connecting portion 50 are integrally formed, for example, by performing welding. This can prevent contaminants from being mixed in from the connecting portion.

<Condenser 2>
The condenser 2 cools and condenses the vaporized organic solvent supplied from the evaporator 1, and supplies the condensed organic solvent to the recovery unit 3. As shown in FIGS. 1 and 2, the condenser 2 includes a distillation column unit 30, a cooling unit 40, a connection unit 50 on the evaporator 1 side, and a connection unit 60 on the recovery unit 3 side. The condenser 2 may be composed of two components so that the distillation column section 30 and the connection section 50 and the cooling section 40 and the connection section 60 can be separated from each other.

  The shape and size of the connecting portion 50 of the condenser 2 may be any shape as long as the connecting portion 50 can be stably fixed to the connecting portion 21 of the evaporator 1 without any gap. For example, as a specific example, the connecting portion 50 has a cylindrical shape with an inner diameter of 2 cm and a length of 1.3 cm so that the vaporized organic solvent can easily pass through. The contact portion of the connecting portion 50 with the connecting portion 21 is preferably integrally formed by, for example, welding. This can prevent contaminants from being mixed in from the connecting portion.

  The distillation column section 30 of the condenser 2 has, for example, a cylindrical shape, and includes at least one droplet reaching prevention member 31 for preventing droplets of the organic solvent before purification from reaching the cooling section 40. (FIGS. 1 and 2 show four cases). For example, as a specific example, the distillation column 30 has an inner diameter of 2 cm, a thickness of 2 mm, and a length (length from the upper surface of the lid 20 to the top of the distillation column 30) of 6 cm. This can minimize the amount of the droplets of the organic solvent before purification that have been scattered and reach the cooling unit 40. The droplet arrival prevention member 31 will be described later.

  The coupling angle between the distillation column section 30 and the cooling section 40 is preferably 60 ° to 80 °. That is, the cooling unit 40 is preferably inclined downward by 10 ° to 30 ° toward the recovery unit 3 side. Since the cooling unit 40 is inclined downward, the condensed organic solvent can be recovered in the recovery unit 3.

  The cooling unit 40 is a surface condenser having a double pipe structure, and has an inner pipe 43 through which a vaporized organic solvent passes, and an outer pipe 44 through which a cooling solvent passes. The outer tube 44 covers the inner tube 43, and cools and condenses the vaporized organic solvent in the inner tube 43 by passing the cooling solvent through the outer tube 44. The inner tube 43 has a cylindrical shape, for example, an inner diameter of 2 cm, a thickness of 2 mm, and a length (length from the boundary with the distillation column unit 30 to the boundary with the connection unit 60) of 15 cm, to give a specific example. . Thus, the vaporized organic solvent can be sufficiently cooled and condensed.

  The shape of the outer tube 44 is cylindrical, and for example, has a length of 10 cm in a specific example. The outer tube 44 has a cooling solvent inlet 45 and a cooling solvent outlet 46. Examples of the cooling solvent include liquids such as water and brine. The temperature of the cooling solvent may be any temperature at which the vaporized organic solvent can be sufficiently cooled (for example, to room temperature). Further, the rate of supplying the cooling solvent may be any rate at which the vaporized organic solvent can be sufficiently cooled.

  The shape and size of the connecting portion 60 of the condenser 2 may be any shape as long as the connecting portion 60 can be fixed stably to the connecting portion 83 of the collector 3 without any gap. For example, as a specific example, the connecting portion 60 has a truncated cone shape with an inner diameter of 3.6 cm and a length of 10 cm on the side of the recovery unit 3 so that the condensed organic solvent can easily pass through. It is preferable that the length of the connecting portion 60 is such that the distal end portion of the connecting portion 60 projects into the collection device 3 when inserted into the connecting portion 83. It is preferable that a rubbing process is performed on a contact portion of the connecting portion 60 with the connecting portion 83. Thereby, the connection between the condenser 2 and the recovery unit 3 is stabilized, and contamination of contaminants from the connection part can be prevented.

(Droplet arrival prevention member 31)
As shown in FIGS. 1 and 2, a plurality of the droplet arrival preventing members 31 may be provided in the distillation column unit 30. The droplet reaching prevention member 31 is a baffle plate having a role of preventing the vaporized organic solvent from rising in the distillation tower section 30 at the shortest distance and reaching the cooling section 40. Accordingly, each of the droplet arrival preventing members 31 is set to have a length from the fixed portion to the tip end so that the opening side of the connecting portion 50 cannot be seen through when the distillation column portion 30 is viewed from above. . The shape of the droplet reaching prevention member 31 may be any shape as long as it can serve as a baffle plate, and is not particularly limited.

  Further, the droplet reaching prevention member 31 is moved from the fixed portion fixed to the distillation column 30 to the tip portion so that the condensed organic solvent and the droplets of the organic solvent before purification that have become droplets do not stay on the upper surface thereof. It is inclined downward toward. The inclination angle of the droplet arrival preventing member 31 is preferably, for example, 40 ° to 60 °.

  It is preferable that the fixed portion of the droplet arrival prevention member 31 located at the lowermost side (on the side of the evaporator 1) is located at a distance of 2 cm from the upper portion 22 of the lid 20 of the evaporator 1. It is preferable that the fixed portion of the droplet arrival prevention member 31 located at the uppermost position (the cooling portion 40) is located at a distance of 3 cm from the upper portion 22 of the lid 20 of the evaporator 1.

  Since the distillation column unit 30 includes the droplet arrival prevention member 31, it is possible to prevent the droplets of the organic solvent before purification that have become droplets from reaching the cooling unit 40. Therefore, only the vaporized organic solvent is supplied to the cooling unit 40, so that a higher-purity organic solvent can be recovered.

<Recovery device 3>
The recovery device 3 recovers the organic solvent condensed in the condenser 2. The recovery device 3 may be cooled if necessary.

  The shape and size of the recovery device 3 are not particularly limited as long as the condensed (purified) organic solvent can be received. The recovery device 3 discharges the oxidizing gas (atmosphere) and the supplied inert gas that existed in the purification device before the supply of the inert gas, thereby keeping the inside of the purification device 100 at normal pressure. Thus, an inert gas outlet (not shown) is provided.

  As shown in FIG. 1, the recovery device 3 includes a connection portion 83 into which the connection portion 60 of the condenser 2 fits. The shape and size of the connecting portion 83 may be any shape as long as the connecting portion 60 of the condenser 2 is inserted and the connecting portion 60 can be fixed stably without any gap. For example, as a specific example, the connecting portion 83 has a truncated cone shape having an inner diameter of 2.4 cm to 3.0 cm and a length of 3 cm on the condenser 2 side so that the condensed organic solvent can easily pass through. It is preferable that a so-called rubbing process is performed on a contact portion of the connecting portion 83 with the connecting portion 60, similarly to a general glass tool.

  The purified organic solvent recovered in the recovery device 3 is used as an organic solvent for dilution used for analysis in an ultra-trace range (10 ppt) such as inductively coupled plasma mass spectrometry (ICP-MS). The purified organic solvent is stored in the recovery device 3 as needed.

  In the refining apparatus 100 according to one embodiment of the present invention, the evaporator 1, the condenser 2, and the recovery unit 3 in which the contact portion with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more. It has. Therefore, the organic solvent does not come into contact with quartz or a substance other than silicon carbide having a purity of 99.95% by weight or more at the time of purification, and is contained in the organic solvent before purification by vaporizing and condensing the organic solvent before purification. Regardless of the concentration of each metal, the concentration of each metal contained in the purified organic solvent can be reduced to 10 ppt or less, and more preferably, the total concentration of each metal contained in the purified organic solvent is reduced to 10 ppt or less. can do. In particular, the purification device in one embodiment of the present invention purifies an organic solvent in which the concentration of each metal contained as an impurity is 0.1 ppm or less, more preferably 0.05 ppm or less, and the concentration of each metal is 1 ppt or less. Organic solvent.

(Purification method)
The method for purifying an organic solvent according to one embodiment of the present invention includes an evaporation step of heating and evaporating the organic solvent in an evaporator, and condensing the evaporated organic solvent by cooling it using a condenser having a cooling unit. A condensing step, and a recovery step of recovering the condensed organic solvent in a recovery device, comprising: Or silicon carbide having a purity of 99.95% by weight or more. Preferably, the method for purifying an organic solvent in one embodiment of the present invention is performed using the above-described purifying apparatus 100. Further, the method for purifying an organic solvent according to one embodiment of the present invention further includes a washing step of washing the evaporator, the condenser, and the collector with a mixed acid.

  The method for purifying an organic solvent in one embodiment of the present invention is preferably carried out at a normal pressure in a clean environment such as a clean draft or a clean room. This can prevent the organic solvent after purification from being contaminated.

  Hereinafter, a description will be given of a cleaning step, an evaporation step, a condensation step, and a recovery step, which are the respective steps constituting the method for purifying an organic solvent according to an embodiment of the present invention using the above-described purification apparatus 100. However, description of contents that are the same as those described in the organic solvent refining apparatus will be simplified or omitted.

<Washing process>
When the evaporator, the condenser, and the recovery device are used for the first time, it is preferable that the evaporator, the condenser, and the recovery device are previously washed with a general mixed acid before purifying the organic solvent.

  In the washing step, the evaporator, the condenser, and the collector are washed with, for example, a mixed acid of sulfuric acid and nitric acid, and dried. The amount of the mixed acid used for one washing is preferably 100 mL or more (the upper limit is about 500 L), although it depends on the size of each device. It should be noted that the mixed acid is not particularly limited as long as it has a composition and a concentration capable of removing the metal adhering to the evaporator, the condenser and the collector.

  Drying may be any method as long as it does not contaminate each device after washing, and includes, for example, a natural drying method, but is not particularly limited. The washing and drying may be performed at least once, but may be repeated a plurality of times as necessary. When the washing is repeated a plurality of times, the composition and concentration of the mixed acid used may be the same or different. That is, a plurality of types of mixed acids may be properly used depending on the amount and type of the attached metal.

  After the cleaning with the mixed acid is performed once, only the organic solvent after the purification comes into contact, so that the cleaning with the mixed acid can be omitted after use. Further, when the type of the organic solvent to be purified is different from the type of the organic solvent previously purified, it is preferable to wash each device with the organic solvent to be purified and then dry.

<Evaporation process>
In the evaporation step, the organic solvent before purification is injected into the evaporator after washing, and after assembling the purification device, the organic solvent in the evaporator is heated and vaporized by, for example, an electrothermal heating device.

  In the evaporation step, an inert gas is continuously supplied into the evaporator as needed. Thereby, since the organic solvent can be stirred, bumping can be prevented, the vaporization rate (purification rate) of the organic solvent can be increased, and the vaporized organic solvent can be quickly supplied to the condenser. In addition, the combustion supporting gas (atmosphere) can be discharged to prevent an accident.

  In the evaporating step, the droplets of the organic solvent before purification that have become droplets are prevented from reaching the cooling part of the condenser by the droplet arrival preventing member provided in the distillation column part of the condenser.

  In the evaporation step, it is preferable to end the heating in a state where the organic solvent before purification remains in the main body of the evaporator.

  The vaporized organic solvent is provided to the next condensation step.

<Condensation process>
In the condensation step, the vaporized organic solvent is condensed by cooling with a cooling solvent using a cooling section of the condenser. The condensed organic solvent is provided to the next recovery step.

<Recovery process>
In the recovery step, the condensed organic solvent is recovered in a recovery device. Thereby, a purified organic solvent can be obtained.

  The evaporating step, the condensing step, and the recovering step are not performed individually, but are performed substantially simultaneously. That is, the purification method according to one embodiment of the present invention continuously purifies the organic solvent by performing the above-described evaporation step, condensation step, and recovery step as a series of steps.

  The used evaporator, condenser, and recovery device can be repeatedly used by performing the above-described washing step.

  In the refining method according to one embodiment of the present invention, at least a part of the evaporator, the condenser, and the collector that comes into contact with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more. It is a method characterized by the following. For this reason, the organic solvent does not come into contact with quartz or a substance other than silicon carbide having a purity of 99.95% by weight or more at the time of purification, so that the organic solvent before purification is vaporized and condensed, and the metal contained in the organic solvent before purification is removed. Regardless of the concentration of, the concentration of each metal contained in the purified organic solvent can be reduced to 10 ppt or less. In particular, the purification method in one embodiment of the present invention is a method for purifying an organic solvent in which the concentration of each metal contained as an impurity is 0.1 ppm or less, more preferably 0.05 ppm or less, and the concentration of each metal is 1 ppt or less. Organic solvent can be obtained.

  The purified organic solvent is used, for example, as an organic solvent for dilution used for analysis in an ultra-trace range (10 ppt) such as inductively coupled plasma mass spectrometry (ICP-MS).

  The present invention is not limited to the embodiments described above, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention should not be construed as being limited to these Examples.

[Example 1]
Using an organic solvent purifier including an evaporator, a condenser, and a collector made of quartz having a purity of 99.95%, which has been previously washed with a common mixed acid, the total concentration of each metal as an impurity is determined. Purification of propylene glycol monomethyl ether at 0.1 ppm was performed in a clean draft at normal pressure.

  After 700 mL of the above propylene glycol monomethyl ether was injected into the main body of the evaporator, a lid was attached, and the evaporator and the condenser, and the condenser and the collector, were connected to assemble a purification device. Water was passed through the outer tube of the cooling section of the condenser at 20 mL / sec. In addition, high-purity argon gas was continuously supplied to the evaporator at a rate of 7 mL / sec to 10 mL / sec from the start to the end of the purification.

  After the inside of the evaporator was set to an argon gas atmosphere, the evaporator was heated to 160 ° C. by a heater to evaporate the organic solvent and condensed by the condenser. Heating was terminated in a state where propylene glycol monomethyl ether before purification remained in the evaporator.

  The amount of the organic solvent after the purification was 500 mL, and the recovery rate was 71%. As a result of analysis using an induction plasma mass spectrometer, the total concentration of each metal as an impurity contained in the purified organic solvent was 7.2 ppt. Therefore, propylene glycol monomethyl ether having a total concentration of each metal of 10 ppt or less was obtained from propylene glycol monomethyl ether having a total concentration of each metal of 0.1 ppm.

  From the above results, it was found that according to the apparatus and method for purifying an organic solvent according to one embodiment of the present invention, the concentration of each metal contained in the organic solvent can be reduced to 10 ppt or less.

  The apparatus and method for purifying an organic solvent according to one embodiment of the present invention are suitably used, for example, in the production of an organic solvent for dilution used for analysis in an ultra-trace range such as inductively coupled plasma mass spectrometry (ICP-MS). Can be

DESCRIPTION OF SYMBOLS 1 Evaporator 2 Condenser 3 Recovery device 10 Main body 20 Lid 21 Connection part 30 Distillation tower part 31 Droplet prevention member 40 Cooling part 50 Connection part 60 Connection part 83 Connection part

Claims (5)

An evaporator that heats and vaporizes the organic solvent, a condenser that has a cooling unit that cools and condenses the vaporized organic solvent, and a recovery device that recovers the condensed organic solvent,
At least the contact portion of the evaporator, the condenser and the recovery device with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more,
The condenser has a distillation column unit, the distillation column unit includes a plurality of droplet arrival prevention members that prevent the droplets of the organic solvent before purification reach the cooling unit,
The above-mentioned droplet arrival preventing member is inclined downward from the fixing portion fixed to the distillation column toward the tip, and the fixing portion of the lowermost droplet reaching preventing member is a lid of the evaporator. The organic solvent refining device, wherein the fixing portion of the uppermost drop-prevention member is located at a distance of 3 cm from the upper portion of the lid of the evaporator .   The organic solvent refining device according to claim 1, wherein the evaporator includes an inert gas supply port for supplying an inert gas into the evaporator. An evaporation step of heating and vaporizing the organic solvent in the evaporator,
A condensing step of condensing the vaporized organic solvent by cooling using a condenser having a cooling unit,
A recovery process of recovering the condensed organic solvent in a recovery device,
A method for purifying an organic solvent comprising:
At least the contact portion of the evaporator, the condenser and the recovery device with the organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more,
The condenser has a distillation column portion provided with a plurality of droplet arrival prevention members, the droplet arrival prevention member is downwardly inclined from a fixed portion fixed to the distillation column portion toward the tip end , The fixing part of the lowermost drop prevention member is located at a distance of 2 cm from the upper part of the lid of the evaporator, and the fixing part of the lowermost drop prevention member is the lid of the evaporator. Is located at a distance of 3 cm from the upper part, and prevents the droplets of the organic solvent before purification from reaching the cooling part by the droplet arrival prevention member.
Purification method of organic solvent.   The method according to claim 3, wherein an inert gas is supplied to the evaporator in the evaporating step.   The method for purifying an organic solvent according to claim 3 or 4, further comprising a washing step of washing the evaporator, the condenser, and the collector with a mixed acid.

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