JP2019150791A - Refiner and refining method of organic solvent - Google Patents

Abstract

To provide a refiner and a refining method of an organic solvent capable of reducing a concentration of each metal contained in the organic solvent to 10ppt or lower.SOLUTION: A refiner includes a vaporizer for heating and vaporizing an organic solvent, a condenser having a cooling part for cooling and condensing vaporized organic solvent, and a recovery unit for recovering condensed organic solvent, in which at least each contact part with the organic solvent at the vaporizer, the condenser and the recovery unit is constituted of quartz or silicon carbide having a purity of 99.95 wt% or higher.SELECTED DRAWING: Figure 1

Description

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

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

  For example, Patent Document 1 describes a distillation purification method and distillation purification apparatus for a liquid containing a low-volatile impurity such as a metal component. Patent Document 2 describes a method for purifying isopropyl alcohol containing As, B, Se, and Ge.

JP 2001-009201 A Japanese Patent Laid-Open No. 10-109948

  In recent years, for example, due to the development of analysis technology in the ultra-trace range such as inductively coupled plasma mass spectrometry (ICP-MS), further increase in the purity of the organic solvent for dilution used for analysis is required. Further, organic solvents used in the manufacture of electronic devices and resist photosensitizers are also required to have higher purity.

  However, in the distillation purification method and distillation purification apparatus of Patent Document 1, the concentration of the low-volatile impurities contained in the liquid can be set to the ppb order, but cannot be set to the ppt order.

  Moreover, although the refinement | purification method of patent document 2 can make the density | concentration of the metal contained in isopropyl alcohol into a ppt order, the object metal is restricted to As, B, Se, and Ge, and it is various. It cannot be applied to metals.

  An object of one embodiment of the present invention is to provide an organic solvent refining device and a refining method that can reduce the concentration of each metal contained in the organic solvent to 10 ppt or less.

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

That is, the present invention includes the inventions described in [1] to [8] below.
[1] An evaporator that heats and vaporizes an organic solvent, a condenser having a cooling unit that cools and condenses the vaporized organic solvent, and a recovery device that recovers the condensed organic solvent, and includes at least the above evaporation The apparatus for purifying an organic solvent, wherein the contact portion with the organic solvent in the vessel, the condenser and the recovery unit is composed of quartz or silicon carbide having a purity of 99.95% by weight or more.
[2] The condenser has a distillation tower section, and the distillation tower section includes a droplet arrival prevention member for preventing droplets of the organic solvent before purification from reaching the cooling section. [1] An organic solvent refining device according to 1.
[3] The organic solvent purifier according to [1] or [2], wherein the evaporator includes an inert gas supply port for supplying an inert gas therein.
[4] An evaporation step for heating and vaporizing the organic solvent in the evaporator, a condensation step for cooling and condensing the vaporized organic solvent using a condenser having a cooling unit, and a collector for collecting the condensed organic solvent And a recovery step for recovering the organic solvent, wherein at least the contact portion with the organic solvent in the evaporator, condenser, and recovery unit is quartz or silicon carbide having a purity of 99.95 wt% or more. A method for purifying an organic solvent, comprising:
[5] The condenser has a distillation tower portion provided with a droplet arrival prevention member, and prevents the droplets of the organic solvent before purification from reaching the cooling portion by the droplet arrival prevention member. [4] 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 evaporation 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 including 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, there is an effect that it is possible to provide an organic solvent refining apparatus and a refining method that can reduce the concentration of each metal contained in the organic solvent to 10 ppt or less.

It is a front view which shows the schematic structure of the refiner | purifier which concerns on one embodiment of this invention. It is a front view which shows the cover body of an 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 the sectional view on 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 modifications can be made within the scope described, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also applicable. It is included in the technical scope of the present invention. In the present 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 synonymous.

(Organic solvent)
Although it does not specifically limit as an organic solvent refine | purified in 1 aspect of this invention, For example, Alcohol, such as methanol, ethanol, 1-propanol, 2-propanol, propylene glycol; Aliphatic hydrocarbons, such as hexane and heptane; Dichloromethane Halogenated hydrocarbons such as chloroform, aromatic hydrocarbons such as toluene and pyridine, esters such as ethyl acetate and γ-butyllactone, ketones such as acetone and methyl amyl ketone, 1,4-dioxane, tetrahydrofuran and phenylglycidyl 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 less, specifically 1 ppm or less, more preferably 0.1 ppm or less, More preferably, it is 1 ppb or less. In addition, the said density | concentration points out the density | concentration of total amount, when the organic solvent contains multiple types of metals.

  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 purification device and the purification method according to one embodiment of the present invention remove a metal contained as an impurity in an organic solvent and increase the purity of the organic solvent. Organic substances that are impurities other than metals contained in the organic solvent, such as high-boiling components and low-boiling components, are removed by conventional purification apparatuses and purification methods.

[Purification equipment]
An organic solvent purification apparatus according to an embodiment of the present invention includes an evaporator that heats and vaporizes an organic solvent, a condenser that includes a cooling unit that cools and condenses the vaporized organic solvent, and a condensed organic solvent. And at least a contact portion with the organic solvent in the evaporator, the condenser, and the collector is made of quartz or silicon carbide having a purity of 99.95% by weight or more.

  In the purification apparatus, the contact portion with the organic solvent in the evaporator, the condenser, and the collector is made of quartz or silicon carbide having a purity of 99.95% by weight or more. In the present invention, the “organic solvent” in contact with the contact site is not only an organic solvent before purification, but also any state such as a vaporized organic solvent (organic solvent gas) and a condensed (purified) organic solvent. Refers to organic solvents.

  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 at a portion other than the contact portion with the organic solvent. In addition, quartz is preferably synthetic quartz because of its higher purity.

  When the evaporator, condenser and collector are made of silicon carbide, it is difficult to process the silicon carbide into the shape of these evaporators, condensers and collectors, so it is made of other materials. The contact sites of the evaporator, condenser and collector are preferably coated with silicon carbide.

  Hereinafter, each member which comprises a refiner | purifier is demonstrated, referring FIGS. As shown in FIG. 1, the purification apparatus 100 according to an embodiment of the present invention includes at least an evaporator 1, a condenser 2, and a recovery unit 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 purification apparatus 100 is used at normal pressure in a clean environment such as a clean draft or a clean room. Thereby, it can prevent that the organic solvent after refinement | purification is contaminated. Further, when used for the first time, the evaporator 1, the condenser 2, and the recovery unit 3 are used after being washed with a mixed acid, as will be 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 for injecting an organic solvent before purification, and a lid body 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, as a specific example, the shape and size of the main body 10 have a flat bottom surface, an inner diameter of 14 cm, a height of 9 cm, and a bottom surface and side surface thickness of 5 mm. Thereby, since the heating area and the liquid surface area can be relatively increased as compared with the amount of the injected organic solvent, the organic solvent can be vaporized more quickly.

  The main body 10 is used by being mounted on, for example, an electrothermal heating device (so-called hot plate or heater). The temperature for heating the organic solvent before purification is not particularly limited as long as it is not lower than the boiling point of the organic solvent and lower than the boiling point of the metal to be removed. Moreover, it is preferable to complete | finish heating in the state which the organic solvent before refinement | purification remains in the main body 10 of the evaporator 1. FIG.

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

  As shown in FIGS. 1 and 2, the lid 20 of the evaporator 1 has a disc shape, for example, and mainly includes a lower part 23 fitted to the main body 10 and an upper part 22 that 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 part 22 has a diameter of 15 cm and a thickness of 6.5 mm, and the lower part 23 has a diameter of 13.8 cm and a thickness of 6.5 mm. The lower part 23 prevents the lid 20 from being displaced due to contact with the inner wall of the main body 10 of the evaporator 1 and prevents contamination. The portion of the lower portion 23 that contacts the main body 10 is sufficiently airtight because the main body 10 is sufficiently thick.

  The lid 20 includes 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 inert gas supply pipe 28 extending from the inert gas supply port 27 has an opening 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 the bumping by stirring the organic solvent, increases the vaporization rate (purification rate) of the organic solvent, and quickly supplies the vaporized organic solvent to the condenser 2, thereby supporting the combustion-supporting gas ( In order to prevent accidents by discharging (atmosphere), if necessary, it is supplied to the evaporator 1 and vented to the 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 an inert gas cylinder through a pipe attached to the inert gas supply port 27. The supply rate of the inert gas is not particularly limited as long as the organic solvent is not sprayed (droplets) and may be maintained at a normal pressure in the purification apparatus 100. The inert gas is preferably continuously supplied from the start of purification of the organic solvent to the end of purification. In addition, since a refinement | purification apparatus can supply an inert gas to the evaporator 1 and can stir an organic solvent, it is not necessary to provide a stirring apparatus.

  The lid 20 of the evaporator 1 has a connecting part 21 for inserting the connecting part 50 on the evaporator 1 side of the condenser 2. The connecting portion 21 is preferably in the central portion of the lid 20 of the evaporator 1. The shape and size of the connecting portion 21 may be any shape that can stably fix the connecting portion 50 of the condenser 2 without a gap. For example, if a specific example is given, the connection part 21 is cylindrical shape with an internal diameter of 2 cm so that the vaporized organic solvent may pass easily. It is preferable that the connection part 21 and the connection part 50 are integrally formed, for example by performing a welding process. Thereby, mixing of the contaminant from a connection part can be prevented.

<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 tower 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. In addition, the condenser 2 may be comprised by two structural members so that the distillation tower part 30 and the connection part 50, and the cooling part 40 and the connection part 60 can mutually be isolate | separated.

  The shape and size of the connecting portion 50 of the condenser 2 may be any shape that can be stably fixed to the connecting portion 21 of the evaporator 1 without a gap. For example, if a specific example is given, the connection part 50 is a cylindrical shape with an internal diameter of 2 cm and length of 1.3 cm so that the vaporized organic solvent may pass easily. It is preferable that the contact part with the connection part 21 in the connection part 50 is integrally formed, for example by performing a welding process. Thereby, mixing of the contaminant from a connection part can be prevented.

  The distillation tower section 30 of the condenser 2 has, for example, a cylindrical shape, and includes at least one droplet arrival prevention member 31 that prevents the droplets of the organic solvent before purification, which have become splashes, from reaching the cooling section 40. Provided (FIGS. 1 and 2 show four cases). For example, as a specific example, the distillation tower 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 tower 30) of 6 cm. As a result, it is possible to minimize the amount of droplets of the organic solvent before purification that have become splashes and reach the cooling unit 40. The droplet arrival preventing member 31 will be described later.

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

  The cooling unit 40 is a surface condenser having a double tube structure, and includes an inner tube 43 through which the vaporized organic solvent passes and an outer tube 44 through which the cooling solvent passes. The outer tube 44 covers the inner tube 43, and when the cooling solvent passes through the outer tube 44, the vaporized organic solvent in the inner tube 43 is cooled and condensed. The inner tube 43 has a cylindrical shape. For example, to give a specific example, the inner diameter is 2 cm, the thickness is 2 mm, and the length is 15 cm (the length from the boundary with the distillation tower 30 to the boundary with the connecting portion 60). . Thereby, the vaporized organic solvent can be sufficiently cooled and condensed.

  The shape of the outer tube 44 is cylindrical, and for example, a specific example is 10 cm in length. 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 a temperature at which the vaporized organic solvent can be sufficiently cooled (for example, to room temperature). Moreover, the speed | rate which supplies a cooling solvent should just be a speed | rate which can fully cool the vaporized organic solvent.

  The shape and size of the connecting portion 60 of the condenser 2 may be any shape that can be stably fixed to the connecting portion 83 of the recovery device 3 without a gap. For example, as a specific example, the connecting portion 60 has a truncated cone shape having an inner diameter of 3.6 cm and a length of 10 cm on the collector 3 side so that the condensed organic solvent can easily pass therethrough. It is preferable that the length of the connecting portion 60 is a length such that a tip portion of the connecting portion 60 protrudes into the collecting device 3 when inserted into the connecting portion 83. The contact portion of the connecting portion 60 with the connecting portion 83 is preferably subjected to rubbing processing. Thereby, the connection between the condenser 2 and the recovery unit 3 is stabilized, and contamination from the connection portion can be prevented.

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

  In addition, the droplet arrival preventing member 31 has a distal end portion from a fixed portion fixed to the distillation tower portion 30 so that condensed organic solvent or droplets of the organic solvent before purification that have become splashes do not stay on the upper surface thereof. Inclined downward toward The inclination angle of the droplet arrival preventing member 31 is preferably 40 ° to 60 °, for example.

  The fixing portion of the droplet arrival preventing member 31 located on the lowermost side (the evaporator 1 side) is preferably at a distance of 2 cm from the upper part 22 of the lid 20 of the evaporator 1. The fixed portion of the droplet arrival preventing member 31 located on the uppermost side (cooling portion 40) is preferably at a distance of 3 cm from the upper portion 22 of the lid 20 of the evaporator 1.

  By providing the distillation tower section 30 with the droplet arrival preventing member 31, it is possible to prevent the droplets of the organic solvent before purification that have become splashes from reaching the cooling section 40. Therefore, since only the vaporized organic solvent is supplied to the cooling unit 40, a higher-purity organic solvent can be recovered.

<Recoverer 3>
The collector 3 collects the organic solvent condensed by the condenser 2. The collector 3 may be cooled as necessary.

  The shape and size of the recovery device 3 are not particularly limited as long as it can accept the condensed (purified) organic solvent. The recovery device 3 can discharge the combustion-supporting gas (atmosphere) present in the purifier before the supply of the inert gas and the supplied inert gas to keep the interior of the purifier 100 at normal pressure. As described above, an inert gas discharge port (not shown) is provided.

  As shown in FIG. 1, the recovery device 3 includes a connecting portion 83 into which the connecting portion 60 of the condenser 2 is fitted. 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 stably fixed without a 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 therethrough. It is preferable that what is called a rubbing process is given to the contact part with the connection part 60 in the connection part 83 similarly to a general glass instrument.

  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). In addition, the organic solvent after refinement | purification is stored in the collection | recovery device 3 as needed.

  In the purification apparatus 100 according to one embodiment of the present invention, an evaporator 1, a condenser 2 and a recovery unit 3 in which a contact site with an organic solvent is made of quartz or silicon carbide having a purity of 99.95% by weight or more. It has. For this reason, since 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 during purification, it 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 made 10 ppt or less, and more preferably, the total concentration of each metal contained in the refined organic solvent is made 10 ppt or less. can do. In particular, the purification apparatus according to an 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. It can be used as an organic solvent.

[Purification method]
An organic solvent purification method according to an embodiment of the present invention includes an evaporation step in which an organic solvent in an evaporator is heated and vaporized, and the vaporized organic solvent is cooled and condensed using a condenser having a cooling unit. And a recovery step of recovering the condensed organic solvent in a recovery device, wherein at least a contact portion with the organic solvent in the evaporator, the condenser and the recovery device is quartz. Or a method comprising silicon carbide having a purity of 99.95% by weight or more. Preferably, the method for purifying an organic solvent according to an embodiment of the present invention is performed using the purification apparatus 100 described above. Moreover, the purification method of the organic solvent in one embodiment of this invention further includes the washing | cleaning process of wash | cleaning the said evaporator, a condenser, and a collection | recovery device 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. Thereby, it can prevent that the organic solvent after refinement | purification is contaminated.

  Hereinafter, the cleaning process, the evaporation process, the condensation process, and the recovery process, which are the processes constituting the organic solvent purification method according to the embodiment of the present invention, using the purification apparatus 100 described above will be described. However, the description overlapping with the content described in the organic solvent refining apparatus described above will be simplified or omitted.

<Washing process>
When the evaporator, the condenser and the collector are used for the first time, it is preferable to wash them in advance 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 instrument. The mixed acid is not particularly limited as long as it has a composition and concentration that can remove the metal adhering to the evaporator, the condenser, and the collector.

  The drying is not particularly limited as long as it is a method that does not contaminate each instrument after washing, and examples include a method of natural drying. The washing and drying may be performed at least once, but may be repeated a plurality of times as necessary. In addition, when repeating washing | cleaning in multiple times, the composition and density | concentration of the mixed acid to be used may be mutually the same, and may differ. In other words, a plurality of types of mixed acids may be properly used depending on the amount and type of the deposited metal.

  After washing with the mixed acid once, only the purified organic solvent comes into contact with it, so that washing with the mixed acid can be omitted after use. Moreover, when the kind of organic solvent to refine | purify differs from the kind of organic solvent refine | purified last time, it is preferable to dry after wash | cleaning each instrument with the organic solvent to refine | purify.

<Evaporation process>
In the evaporation step, the organic solvent before purification is injected into the cleaned evaporator, the purification apparatus is assembled, and then the organic solvent in the evaporator is heated and vaporized by, for example, an electrothermal heating apparatus.

  In the evaporation step, an inert gas is continuously supplied into the evaporator as necessary. As a result, the organic solvent can be stirred, so that 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. It is possible to prevent accidents by discharging combustion-supporting gas (atmosphere).

  Also, in the evaporation step, the droplets of the organic solvent before purification, which have become splashes, are prevented from reaching the cooling section of the condenser by the droplet arrival prevention member provided in the distillation tower section 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 subjected to the next condensation step.

<Condensation process>
In the condensation step, the vaporized organic solvent is cooled and condensed by the cooling solvent using a cooling unit of the condenser. The condensed organic solvent is supplied to the next recovery step.

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

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

  In addition, the used evaporator, condenser, and collection | recovery device can be repeatedly used by performing the washing | cleaning process mentioned above.

  In the purification method according to an embodiment of the present invention, at least the contact portion with the organic solvent in the evaporator, the condenser and the collector is made of quartz or silicon carbide having a purity of 99.95% by weight or more. It is the method characterized by this. For this reason, since the organic solvent does not come into contact with quartz or a substance other than silicon carbide with a purity of 99.95% by weight or more during purification, the organic solvent before purification is vaporized and condensed, and the metal contained in the organic solvent before purification Regardless of the concentration, the concentration of each metal contained in the purified organic solvent can be 10 ppt or less. In particular, in the purification method according to an embodiment of the present invention, 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. The organic solvent can be obtained.

  The organic solvent after purification 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 present invention is not limited to the above-described embodiments, 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.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention should not be construed as being limited to these examples.

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

  After injecting 700 mL of the propylene glycol monomethyl ether 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 the purification apparatus. Water was passed at 20 mL / second through the outer tube of the condenser cooling part. Further, high purity argon gas was continuously supplied to the evaporator from 7 mL / second to 10 mL / second from the start to the end of purification.

  And after making the inside of an evaporator into argon gas atmosphere, the evaporator was heated to 160 degreeC with the heater, the organic solvent was vaporized, and it condensed with the condenser. Heating was completed with propylene glycol monomethyl ether before purification remaining in the evaporator.

  The amount of the organic solvent after 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. Accordingly, propylene glycol monomethyl ether having a total concentration of each metal of 10 ppt or less could be 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 the concentration of each metal contained in the organic solvent can be reduced to 10 ppt or less according to the purification apparatus and the purification method of the organic solvent according to one embodiment of the present invention.

  The organic solvent purification apparatus and purification method according to an embodiment of the present invention are preferably used in the production of an organic solvent for dilution used for analysis in ultratrace regions such as inductively coupled plasma mass spectrometry (ICP-MS). It is done.

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

Claims (8)

An evaporator for heating and vaporizing the organic solvent, a condenser having a cooling unit for cooling and condensing the vaporized organic solvent, and a recovery unit for collecting the condensed organic solvent,
An apparatus for purifying an organic solvent, wherein at least a contact portion with the organic solvent in the evaporator, the condenser and the collector is composed of quartz or silicon carbide having a purity of 99.95% by weight or more.   The said condenser has a distillation tower part, The said distillation tower part is equipped with the droplet arrival prevention member which prevents the droplet of the organic solvent before refinement | purification from reaching the said cooling part. Organic solvent purification equipment.   The said solvent is a refiner | purifier of the organic solvent of Claim 1 or 2 provided with the inert gas supply port which supplies an inert gas to an inside. An evaporation step of heating and vaporizing the organic solvent in the evaporator;
A condensation step of condensing the vaporized organic solvent by cooling using a condenser having a cooling unit;
A recovery process for recovering the condensed organic solvent in a recovery device;
A method for purifying an organic solvent comprising
A method for purifying an organic solvent, wherein at least a contact portion with the organic solvent in the evaporator, the condenser and the collector is composed of quartz or silicon carbide having a purity of 99.95% by weight or more.   The said condenser has a distillation tower part provided with the droplet arrival prevention member, and prevents the droplet of the organic solvent before refinement | purification from reaching the said cooling part with the said droplet arrival prevention member. A method for purifying an organic solvent as described in 1.   The method for purifying an organic solvent according to claim 4 or 5, wherein an inert gas is supplied to the evaporator in the evaporation step.   The method for purifying an organic solvent according to any one of claims 4 to 6, further comprising a washing step of washing the evaporator, the condenser and the collector with a mixed acid.   An organic solvent in which the concentration of each metal contained as an impurity is 10 ppt or less.

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